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Thermostable DNA ligase-mediated PCR production of circular plasmid (PPCP) and its application in directed evolution via in situ error-prone PCR.
Le, Yilin; Chen, Huayou; Zagursky, Robert; Wu, J H David; Shao, Weilan
Polymerase chain reaction (PCR) is a powerful method to produce linear DNA fragments. Here we describe the Tma thermostable DNA ligase-mediated PCR production of circular plasmid (PPCP) and its application in directed evolution via in situ error-prone PCR. In this thermostable DNA ligase-mediated whole-plasmid amplification method, the resultant DNA nick between the 5' end of the PCR primer and the extended newly synthesized DNA 3' end of each PCR cycle is ligated by Tma DNA ligase, resulting in circular plasmid DNA product that can be directly transformed. The template plasmid DNA is eliminated by 'selection marker swapping' upon transformation. When performed under an error-prone condition with Taq DNA polymerase, PPCP allows one-step construction of mutagenesis libraries based on in situ error-prone PCR so that random mutations are introduced into the target gene without altering the expression vector plasmid. A significant difference between PPCP and previously published methods is that PPCP allows exponential amplification of circular DNA. We used this method to create random mutagenesis libraries of a xylanase gene and two cellulase genes. Screening of these libraries resulted in mutant proteins with desired properties, demonstrating the usefulness of in situ error-prone PPCP for creating random mutagenesis libraries for directed evolution.
Identification of the antigenic determinants of the American cockroach allergen Per a 1 by error-prone PCR.
Tsai, Wei-Jen; Liu, Ching-Hang; Chen, Shu-Tsung; Yang, Chiou-Ying
The group I allergen of cockroach is found in both American and German cockroaches, designated as Per a 1 and Bla g 1, respectively. Members of these allergens so far identified are composed of tandem repeats that may cause the high allergenicity of Per a 1 allergen. In this study, we used monoclonal antibodies HW-8 and HW-19, which can inhibit the binding of patient IgE to Per a 1 allergen, to define the structure of the antigenic determinants in Per a 1.0103 (designated C3), an isoallergen of Per a 1 allergen. Two recognition sites are present, one in the N-terminus (aa 1-208) and the other in the C-terminus (aa 208-395). The N-terminal epitope is not accessible to antibody molecules on the pET-expressed C3 protein. The C-terminal epitope was further localized to the aa 267-354 region (C3E) by colony immunoscreening of the cDNA epitope library. By negative screening of the mutated C3E expression library generated by error-prone PCR (ER-PCR), an approach which has rarely been applied in epitope mapping, the functional epitope was identified to lie in aa 318-337 with aa 323-331 being the core motif. The minimal region of the functional epitope was further delineated, by sequence alignment, to be D-x-[I, L]-A-[I, L]-L-P-V-D-E-[L, I]-x-A-[L, I], where x represents any amino acids. This motif is found in all Per a 1 allergens and may serve as a basis for designing a peptide vaccine for allergen-specific immunotherapy. To our knowledge, this is the first report for (1) detailed mapping of the cockroach allergens and (2) use of error-prone PCR random mutagenesis and negative selection in molecular allergology.
Error-Prone PCR-Based Mutagenesis Strategy for Rapidly Generating High-Yield Influenza Vaccine Candidates
Ye, Jianqiang; Wen, Feng; Xu, Yifei; Zhao, Nan; Long, Liping; Sun, Hailiang; Yang, Jialiang; Cooley, Jim; Pharr, G. Todd; Webby, Richard; Wan, Xiu-Feng
Vaccination is the primary strategy for the prevention and control of influenza outbreaks. However, the manufacture of influenza vaccine requires a high-yield seed strain, and the conventional methods for generating such strains are time consuming. In this study, we developed a novel method to rapidly generate high-yield candidate vaccine strains by integrating error-prone PCR, site-directed mutagenesis strategies, and reverse genetics. We used this method to generate seed strains for the influenza A(H1N1)pdm09 virus and produced six high-yield candidate strains. We used a mouse model to assess the efficacy of two of the six candidate strains as a vaccine seed virus: both strains provided complete protection in mice against lethal challenge, thus validating our method. Results confirmed that the efficacy of these candidate vaccine seed strains was not affected by the yield-optimization procedure. PMID:25899178
Improved activity and pH stability of E. coli ATCC 11105 penicillin acylase by error-prone PCR.
Balci, Huseyin; Ozturk, Merve Tuzlakoglu; Pijning, Tjaard; Ozturk, Saliha Issever; Gumusel, Fusun
Penicillin G acylase is the key enzyme used in the industrial production of β-lactam antibiotics. This enzyme hydrolyzes penicillin G and related β-lactam antibiotics releasing 6-aminopenicillanic acid, which is an intermediate in the production of semisynthetic penicillins. To improve the enzymatic activity of Escherichia coli penicillin acylase, sequential rounds of error-prone polymerase chain reaction were applied to the E. coli pac gene. After the second round of evolution, the best mutant M2234 with enhanced activity was selected and analyzed. DNA sequence analyses of M2234 revealed that one amino acid residue (K297I), located far from the center of the catalytic pocket, was changed. This mutant (M2234) has a specific activity 4.0 times higher than the parent enzyme and also displayed higher stability at pH 10.
Directed Evolution and Resolution Mechanism of 1, 3-Propanediol Oxidoreductase from Klebsiella pneumoniae toward Higher Activity by Error-Prone PCR and Bioinformatics.
Jiang, Wei; Zhuang, Yuan; Wang, Shizhen; Fang, Baishan
1, 3-propanediol oxidoreductase (PDOR) is a key enzyme in glycerol bioconversion to 1,3-propanediol (1, 3-PD) which is a valuable chemical and one of the six new petrochemical products. We used error-prone PCR and activity screening to identify mutants of Klebsiella pneumoniae (K. pneumoniae) PDOR with improved activity. The activity of one of the identified mutants, PDOR'-24, which includes a single mutation, A199S, was 48 U/mg, 4.9 times that of the wild-type enzyme. Molecular docking was performed to analyze the identified mutants; and amino acids S103, H271, N366, D106, N262 and D364 were predicted to bond with NADH. The origins of the improved activity of PDOR'-24, as well as three other mutants were analyzed by simulating the interaction mechanism of the mutants with the substrate and coenzyme, respectively. This research provides useful information about the use of safranine O plate screening for the directed evolution of oxidoreductases, identifies interesting sites for improving PDOR activity, and demonstrates the utility of using molecular docking to analyze the interaction mechanism of the mutants with the substrate and coenzyme, respectively.
Improvement of enzyme activity of β-1,3-1,4-glucanase from Paenibacillus sp. X4 by error-prone PCR and structural insights of mutated residues.
Baek, Seung Cheol; Ho, Thien-Hoang; Lee, Hyun Woo; Jung, Won Kyeong; Gang, Hyo-Seung; Kang, Lin-Woo; Kim, Hoon
β-1,3-1,4-Glucanase (BGlc8H) from Paenibacillus sp. X4 was mutated by error-prone PCR or truncated using termination primers to improve its enzyme properties. The crystal structure of BGlc8H was determined at a resolution of 1.8 Å to study the possible roles of mutated residues and truncated regions of the enzyme. In mutation experiments, three clones of EP 2-6, 2-10, and 5-28 were finally selected that exhibited higher specific activities than the wild type when measured using their crude extracts. Enzyme variants of BG2-6, BG2-10, and BG5-28 were mutated at two, two, and six amino acid residues, respectively. These enzymes were purified homogeneously by Hi-Trap Q and CHT-II chromatography. Specific activity of BG5-28 was 2.11-fold higher than that of wild-type BGwt, whereas those of BG2-6 and BG2-10 were 0.93- and 1.19-fold that of the wild type, respectively. The optimum pH values and temperatures of the variants were nearly the same as those of BGwt (pH 5.0 and 40 °C, respectively). However, the half-life of the enzyme activity and catalytic efficiency (k cat/K m) of BG5-28 were 1.92- and 2.12-fold greater than those of BGwt at 40 °C, respectively. The catalytic efficiency of BG5-28 increased to 3.09-fold that of BGwt at 60 °C. These increases in the thermostability and catalytic efficiency of BG5-28 might be useful for the hydrolysis of β-glucans to produce fermentable sugars. Of the six mutated residues of BG5-28, five residues were present in mature BGlc8H protein, and two of them were located in the core scaffold of BGlc8H and the remaining three residues were in the substrate-binding pocket forming loop regions. In truncation experiments, three forms of C-terminal truncated BGlc8H were made, which comprised 360, 286, and 215 amino acid residues instead of the 409 residues of the wild type. No enzyme activity was observed for these truncated enzymes, suggesting the complete scaffold of the α6/α6-double-barrel structure is essential for enzyme
Random Mutagenesis by Error-Prone Polymerase Chain Reaction Using a Heavy Water Solvent.
Minamoto, Toshifumi
Heavy water is a form of water that contains a heavier isotope of hydrogen ((2)H, also known as deuterium, D) or oxygen ((17)O or (18)O). When using heavy water as a solvent, error-prone polymerase chain reaction (epPCR) can induce random mutations independent of the polymerase used or the composition of the PCR reaction mixture. This relatively new method can easily be combined with the existing epPCR methods to increase the rate of mutations.
Size and Shape Analysis of Error-Prone Shape Data
Du, Jiejun; Dryden, Ian L.; Huang, Xianzheng
We consider the problem of comparing sizes and shapes of objects when landmark data are prone to measurement error. We show that naive implementation of ordinary Procrustes analysis that ignores measurement error can compromise inference. To account for measurement error, we propose the conditional score method for matching configurations, which guarantees consistent inference under mild model assumptions. The effects of measurement error on inference from naive Procrustes analysis and the performance of the proposed method are illustrated via simulation and application in three real data examples. Supplementary materials for this article are available online. PMID:26109745
Population size estimation in Yellowstone wolves with error-prone noninvasive microsatellite genotypes.
Creel, Scott; Spong, Goran; Sands, Jennifer L; Rotella, Jay; Zeigle, Janet; Joe, Lawrence; Murphy, Kerry M; Smith, Douglas
Determining population sizes can be difficult, but is essential for conservation. By counting distinct microsatellite genotypes, DNA from noninvasive samples (hair, faeces) allows estimation of population size. Problems arise because genotypes from noninvasive samples are error-prone, but genotyping errors can be reduced by multiple polymerase chain reaction (PCR). For faecal genotypes from wolves in Yellowstone National Park, error rates varied substantially among samples, often above the 'worst-case threshold' suggested by simulation. Consequently, a substantial proportion of multilocus genotypes held one or more errors, despite multiple PCR. These genotyping errors created several genotypes per individual and caused overestimation (up to 5.5-fold) of population size. We propose a 'matching approach' to eliminate this overestimation bias.
Random mutagenesis by error-prone pol plasmid replication in Escherichia coli.
Alexander, David L; Lilly, Joshua; Hernandez, Jaime; Romsdahl, Jillian; Troll, Christopher J; Camps, Manel
Directed evolution is an approach that mimics natural evolution in the laboratory with the goal of modifying existing enzymatic activities or of generating new ones. The identification of mutants with desired properties involves the generation of genetic diversity coupled with a functional selection or screen. Genetic diversity can be generated using PCR or using in vivo methods such as chemical mutagenesis or error-prone replication of the desired sequence in a mutator strain. In vivo mutagenesis methods facilitate iterative selection because they do not require cloning, but generally produce a low mutation density with mutations not restricted to specific genes or areas within a gene. For this reason, this approach is typically used to generate new biochemical properties when large numbers of mutants can be screened or selected. Here we describe protocols for an advanced in vivo mutagenesis method that is based on error-prone replication of a ColE1 plasmid bearing the gene of interest. Compared to other in vivo mutagenesis methods, this plasmid-targeted approach allows increased mutation loads and facilitates iterative selection approaches. We also describe the mutation spectrum for this mutagenesis methodology in detail, and, using cycle 3 GFP as a target for mutagenesis, we illustrate the phenotypic diversity that can be generated using our method. In sum, error-prone Pol I replication is a mutagenesis method that is ideally suited for the evolution of new biochemical activities when a functional selection is available.
Designing an Algorithm to Preserve Privacy for Medical Record Linkage With Error-Prone Data
Pal, Doyel; Chen, Tingting; Khethavath, Praveen
Background Linking medical records across different medical service providers is important to the enhancement of health care quality and public health surveillance. In records linkage, protecting the patients' privacy is a primary requirement. In real-world health care databases, records may well contain errors due to various reasons such as typos. Linking the error-prone data and preserving data privacy at the same time are very difficult. Existing privacy preserving solutions for this problem are only restricted to textual data. Objective To enable different medical service providers to link their error-prone data in a private way, our aim was to provide a holistic solution by designing and developing a medical record linkage system for medical service providers. Methods To initiate a record linkage, one provider selects one of its collaborators in the Connection Management Module, chooses some attributes of the database to be matched, and establishes the connection with the collaborator after the negotiation. In the Data Matching Module, for error-free data, our solution offered two different choices for cryptographic schemes. For error-prone numerical data, we proposed a newly designed privacy preserving linking algorithm named the Error-Tolerant Linking Algorithm, that allows the error-prone data to be correctly matched if the distance between the two records is below a threshold. Results We designed and developed a comprehensive and user-friendly software system that provides privacy preserving record linkage functions for medical service providers, which meets the regulation of Health Insurance Portability and Accountability Act. It does not require a third party and it is secure in that neither entity can learn the records in the other's database. Moreover, our novel Error-Tolerant Linking Algorithm implemented in this software can work well with error-prone numerical data. We theoretically proved the correctness and security of our Error
Analysis of error-prone survival data under additive hazards models: measurement error effects and adjustments.
Yan, Ying; Yi, Grace Y
Covariate measurement error occurs commonly in survival analysis. Under the proportional hazards model, measurement error effects have been well studied, and various inference methods have been developed to correct for error effects under such a model. In contrast, error-contaminated survival data under the additive hazards model have received relatively less attention. In this paper, we investigate this problem by exploring measurement error effects on parameter estimation and the change of the hazard function. New insights of measurement error effects are revealed, as opposed to well-documented results for the Cox proportional hazards model. We propose a class of bias correction estimators that embraces certain existing estimators as special cases. In addition, we exploit the regression calibration method to reduce measurement error effects. Theoretical results for the developed methods are established, and numerical assessments are conducted to illustrate the finite sample performance of our methods.
Error-prone and error-restrictive mutations affecting ribosomal protein S12.
Agarwal, Deepali; Gregory, Steven T; O'Connor, Michael
Ribosomal protein S12 plays a pivotal role in decoding functions on the ribosome. X-ray crystallographic analyses of ribosomal complexes have revealed that S12 is involved in the inspection of codon-anticodon pairings in the ribosomal A site, as well as in the succeeding domain rearrangements of the 30S subunit that are essential for accommodation of aminoacyl-tRNA. A role for S12 in tRNA selection is also well supported by classical genetic analyses; mutations affecting S12 are readily isolated in bacteria and organelles, since specific alterations in S12 confer resistance to the error-inducing antibiotic streptomycin, and the ribosomes from many such streptomycin-resistant S12 mutants display decreased levels of miscoding. However, substitutions that confer resistance to streptomycin likely represent a very distinct class of all possible S12 mutants. Until recently, the technical difficulties in generating random, unselectable mutations in essential genes in complex operons have generally precluded the analysis of other classes of S12 alterations. Using a recombineering approach, we have targeted the Escherichia coli rpsL gene, encoding S12, for random mutagenesis and screened the resulting mutants for effects on decoding fidelity. We have recovered over 40 different substitutions located throughout the S12 protein that alter the accuracy of translation without substantially affecting the sensitivity to streptomycin. Moreover, this collection includes mutants that promote miscoding, as well as those that restrict decoding errors. These results affirm the importance of S12 in decoding processes and indicate that alterations in this essential protein can have diverse effects on the accuracy of decoding.
Error-prone translesion replication of damaged DNA suppresses skin carcinogenesis by controlling inflammatory hyperplasia
Tsaalbi-Shtylik, Anastasia; Verspuy, Johan W. A.; Jansen, Jacob G.; Rebel, Heggert; Carlée, Leone M.; van der Valk, Martin A.; Jonkers, Jos; de Gruijl, Frank R.; de Wind, Niels
The induction of skin cancer involves both mutagenic and proliferative responses of the epidermis to ultraviolet (UV) light. It is believed that tumor initiation requires the mutagenic replication of damaged DNA by translesion synthesis (TLS) pathways. The mechanistic basis for the induction of proliferation, providing tumor promotion, is poorly understood. Here, we have investigated the role of TLS in the initiation and promotion of skin carcinogenesis, using a sensitive nucleotide excision repair-deficient mouse model that carries a hypomorphic allele of the error-prone TLS gene Rev1. Despite a defect in UV-induced mutagenesis, skin carcinogenesis was accelerated in these mice. This paradoxical phenotype was caused by the induction of inflammatory hyperplasia of the mutant skin that provides strong tumor promotion. The induction of hyperplasia was associated with mild and transient replicational stress of the UV-damaged genome, triggering DNA damage signaling and senescence. The concomitant expression of Interleukin-6 (IL-6) is in agreement with an executive role for IL-6 and possibly other cytokines in the autocrine induction of senescence and the paracrine induction of inflammatory hyperplasia. In conclusion, error-prone TLS suppresses tumor-promoting activities of UV light, thereby controlling skin carcinogenesis. PMID:20007784
Inducible error-prone repair in B. subtilis. Final report, September 1, 1979-June 30, 1981
Yasbin, R. E.
The research performed under this contract has been concentrated on the relationship between inducible DNA repair systems, mutagenesis and the competent state in the gram positive bacterium Bacillus subtilis. The following results have been obtained from this research: (1) competent Bacillus subtilis cells have been developed into a sensitive tester system for carcinogens; (2) competent B. subtilis cells have an efficient excision-repair system, however, this system will not function on bacteriophage DNA taken into the cell via the process of transfection; (3) DNA polymerase III is essential in the mechanism of the process of W-reactivation; (4) B. subtilis strains cured of their defective prophages have been isolated and are now being developed for gene cloning systems; (5) protoplasts of B. subtilis have been shown capable of acquiring DNA repair enzymes (i.e., enzyme therapy); and (6) a plasmid was characterized which enhanced inducible error-prone repair in a gram positive organism.
Interactions and Localization of Escherichia coli Error-Prone DNA Polymerase IV after DNA Damage
Mallik, Sarita; Popodi, Ellen M.; Hanson, Andrew J.
ABSTRACT Escherichia coli's DNA polymerase IV (Pol IV/DinB), a member of the Y family of error-prone polymerases, is induced during the SOS response to DNA damage and is responsible for translesion bypass and adaptive (stress-induced) mutation. In this study, the localization of Pol IV after DNA damage was followed using fluorescent fusions. After exposure of E. coli to DNA-damaging agents, fluorescently tagged Pol IV localized to the nucleoid as foci. Stepwise photobleaching indicated ∼60% of the foci consisted of three Pol IV molecules, while ∼40% consisted of six Pol IV molecules. Fluorescently tagged Rep, a replication accessory DNA helicase, was recruited to the Pol IV foci after DNA damage, suggesting that the in vitro interaction between Rep and Pol IV reported previously also occurs in vivo. Fluorescently tagged RecA also formed foci after DNA damage, and Pol IV localized to them. To investigate if Pol IV localizes to double-strand breaks (DSBs), an I-SceI endonuclease-mediated DSB was introduced close to a fluorescently labeled LacO array on the chromosome. After DSB induction, Pol IV localized to the DSB site in ∼70% of SOS-induced cells. RecA also formed foci at the DSB sites, and Pol IV localized to the RecA foci. These results suggest that Pol IV interacts with RecA in vivo and is recruited to sites of DSBs to aid in the restoration of DNA replication. IMPORTANCE DNA polymerase IV (Pol IV/DinB) is an error-prone DNA polymerase capable of bypassing DNA lesions and aiding in the restart of stalled replication forks. In this work, we demonstrate in vivo localization of fluorescently tagged Pol IV to the nucleoid after DNA damage and to DNA double-strand breaks. We show colocalization of Pol IV with two proteins: Rep DNA helicase, which participates in replication, and RecA, which catalyzes recombinational repair of stalled replication forks. Time course experiments suggest that Pol IV recruits Rep and that RecA recruits Pol IV. These findings
Possible error-prone repair of neoplastic transformation induced by fission-spectrum neutrons
Hill, C.K.; Han, A.; Elkind, M.M.
We have examined the effect of fission-spectrum neutrons from the JANUS reactor at Argonne National Laboratory, delivered either as acute or protracted irradiation, on the incidence of neoplastic transformation in the C3H 1OT1/2 mouse embryo cell line. Acute exposures were delivered at 10 to 38 rads/min, protracted exposures at 0.086 or 0.43 rad/min. The total doses for both ranged from 2.4 to 350 rads. In the low dose region (2.4 to 80 rads), there was a large enhancement in transformation frequency when the neutrons were delivered at the low dose rates compared with the high dose rates, but the survival of the cells was not significantly different between the two exposure conditions. Analysis of the initial parts of the curves shows that the regression line for protracted doses is about 9 times steeper than that for single acute exposures. Finally, the possibility is discussed that an error-prone repair process may be causing the enhanced transformation frequency by protracted neutron exposures. 12 references, 2 figures, 1 table.
Thermoadaptation-directed evolution of chloramphenicol acetyltransferase in an error-prone thermophile using improved procedures.
Kobayashi, Jyumpei; Furukawa, Megumi; Ohshiro, Takashi; Suzuki, Hirokazu
Enhancing the thermostability of thermolabile enzymes extends their practical utility. We previously demonstrated that an error-prone thermophile derived from Geobacillus kaustophilus HTA426 can generate mutant genes encoding enzyme variants that are more thermostable than the parent enzyme. Here, we used this approach, termed as thermoadaptation-directed enzyme evolution, to increase the thermostability of the chloramphenicol acetyltransferase (CAT) of Staphylococcus aureus and successfully generated a CAT variant with an A138T replacement (CAT(A138T)). This variant was heterologously produced, and its enzymatic properties were compared with those of the wild type. We found that CAT(A138T) had substantially higher thermostability than CAT but had comparable activities, showing that the A138T replacement enhanced protein thermostability without affecting the catalytic activity. Because variants CAT(A138S) and CAT(A138V), which were generated via in vitro site-directed mutagenesis, were more thermostable than CAT, the thermostability enhancement resulting from the A138T replacement can be attributed to both the presence of a hydroxyl group and the bulk of the threonine side chain. CAT(A138T) conferred chloramphenicol resistance to G. kaustophilus cells at high temperature more efficiently than CAT. Therefore, the gene encoding CAT(A138T) may be useful as a genetic marker in Geobacillus spp. Notably, CAT(A138T) generation was achieved only by implementing improved procedures (plasmid-based mutations on solid media); previous procedures (chromosome-based mutations in liquid media) were unsuccessful. This result suggests that this improved procedure is crucial for successful thermoadaptation-directed evolution in certain cases and increases the opportunities for generating thermostable enzymes.
A mutant of Escherichia coli showing constitutive expression of the lysogenic induction and error-prone DNA repair pathways.
Mount, D W
A mutant of E. coli (designated the STS mutant) has been isolated in which the phage induction and error-prone DNA repair pathways appear to be expressed constitutively without the cells having received an inducing signal. Phage lambda was not able to lysogenize this mutant, whereas a noninducible mutant of lambda, lambdacIind-, known to synthesize a repressor that is insensitive to the induction mechanism, lysogenized it normally. This result suggested that normal phage repressor was synthesized in the STS mutant but was then inactivated by the induction mechanism. The STS strain also had mutator characteristics, and showed spontaneous, error-prone repair of UV-damaged phage lambda. Derived from a lexA tif sfiA parent strain, the STS mutant carried an additional mutation spr at the lexA locus that resulted in a high level of expression of the induction pathways. The properties of this and related strains provide additional evidence that induction of phage and induction of error-prone DNA repair occur by a similar mechanism, and further suggest a model for the regulation of these pathways. Images PMID:319458
Error-prone DnaE2 Balances the Genome Mutation Rates in Myxococcus xanthus DK1622.
Peng, Ran; Chen, Jiang-He; Feng, Wan-Wan; Zhang, Zheng; Yin, Jun; Li, Ze-Shuo; Li, Yue-Zhong
dnaE is an alpha subunit of the tripartite protein complex of DNA polymerase III that is responsible for the replication of bacterial genome. The dnaE gene is often duplicated in many bacteria, and the duplicated dnaE gene was reported dispensable for cell survivals and error-prone in DNA replication in a mystery. In this study, we found that all sequenced myxobacterial genomes possessed two dnaE genes. The duplicate dnaE genes were both highly conserved but evolved divergently, suggesting their importance in myxobacteria. Using Myxococcus xanthus DK1622 as a model, we confirmed that dnaE1 (MXAN_5844) was essential for cell survival, while dnaE2 (MXAN_3982) was dispensable and encoded an error-prone enzyme for replication. The deletion of dnaE2 had small effects on cellular growth and social motility, but significantly decreased the development and sporulation abilities, which could be recovered by the complementation of dnaE2. The expression of dnaE1 was always greatly higher than that of dnaE2 in either the growth or developmental stage. However, overexpression of dnaE2 could not make dnaE1 deletable, probably due to their protein structural and functional divergences. The dnaE2 overexpression not only improved the growth, development and sporulation abilities, but also raised the genome mutation rate of M. xanthus. We argued that the low-expressed error-prone DnaE2 played as a balancer for the genome mutation rates, ensuring low mutation rates for cell adaptation in new environments but avoiding damages from high mutation rates to cells.
Error-prone DnaE2 Balances the Genome Mutation Rates in Myxococcus xanthus DK1622
Peng, Ran; Chen, Jiang-he; Feng, Wan-wan; Zhang, Zheng; Yin, Jun; Li, Ze-shuo; Li, Yue-zhong
dnaE is an alpha subunit of the tripartite protein complex of DNA polymerase III that is responsible for the replication of bacterial genome. The dnaE gene is often duplicated in many bacteria, and the duplicated dnaE gene was reported dispensable for cell survivals and error-prone in DNA replication in a mystery. In this study, we found that all sequenced myxobacterial genomes possessed two dnaE genes. The duplicate dnaE genes were both highly conserved but evolved divergently, suggesting their importance in myxobacteria. Using Myxococcus xanthus DK1622 as a model, we confirmed that dnaE1 (MXAN_5844) was essential for cell survival, while dnaE2 (MXAN_3982) was dispensable and encoded an error-prone enzyme for replication. The deletion of dnaE2 had small effects on cellular growth and social motility, but significantly decreased the development and sporulation abilities, which could be recovered by the complementation of dnaE2. The expression of dnaE1 was always greatly higher than that of dnaE2 in either the growth or developmental stage. However, overexpression of dnaE2 could not make dnaE1 deletable, probably due to their protein structural and functional divergences. The dnaE2 overexpression not only improved the growth, development and sporulation abilities, but also raised the genome mutation rate of M. xanthus. We argued that the low-expressed error-prone DnaE2 played as a balancer for the genome mutation rates, ensuring low mutation rates for cell adaptation in new environments but avoiding damages from high mutation rates to cells. PMID:28203231
Lung Basal Stem Cells Rapidly Repair DNA Damage Using the Error-Prone Nonhomologous End-Joining Pathway
Weeden, Clare E.; Chen, Yunshun; Ma, Stephen B.; Hu, Yifang; Ramm, Georg; Sutherland, Kate D.; Smyth, Gordon K.
Lung squamous cell carcinoma (SqCC), the second most common subtype of lung cancer, is strongly associated with tobacco smoking and exhibits genomic instability. The cellular origins and molecular processes that contribute to SqCC formation are largely unexplored. Here we show that human basal stem cells (BSCs) isolated from heavy smokers proliferate extensively, whereas their alveolar progenitor cell counterparts have limited colony-forming capacity. We demonstrate that this difference arises in part because of the ability of BSCs to repair their DNA more efficiently than alveolar cells following ionizing radiation or chemical-induced DNA damage. Analysis of mice harbouring a mutation in the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a key enzyme in DNA damage repair by nonhomologous end joining (NHEJ), indicated that BSCs preferentially repair their DNA by this error-prone process. Interestingly, polyploidy, a phenomenon associated with genetically unstable cells, was only observed in the human BSC subset. Expression signature analysis indicated that BSCs are the likely cells of origin of human SqCC and that high levels of NHEJ genes in SqCC are correlated with increasing genomic instability. Hence, our results favour a model in which heavy smoking promotes proliferation of BSCs, and their predilection for error-prone NHEJ could lead to the high mutagenic burden that culminates in SqCC. Targeting DNA repair processes may therefore have a role in the prevention and therapy of SqCC. PMID:28125611
Task engagement and the relationships between the error-related negativity, agreeableness, behavioral shame proneness and cortisol.
Tops, Mattie; Boksem, Maarten A S; Wester, Anne E; Lorist, Monicque M; Meijman, Theo F
Previous results suggest that both cortisol mobilization and the error-related negativity (ERN/Ne) reflect goal engagement, i.e. the mobilization and allocation of attentional and physiological resources. Personality measures of negative affectivity have been associated both to high cortisol levels and large ERN/Ne amplitudes. However, measures of positive social adaptation and agreeableness have also been related to high cortisol levels and large ERN/Ne amplitudes. We hypothesized that, as long as they relate to concerns over social evaluation and mistakes, both personality measures reflecting positive affectivity (e.g. agreeableness) and those reflecting negative affectivity (e.g. behavioral shame proneness) would be associated with an increased likelihood of high task engagement, and hence to increased cortisol mobilization and ERN/Ne amplitudes. We had female subjects perform a flanker task while EEG was recorded. Additionally, the subjects filled out questionnaires measuring mood and personality, and salivary cortisol immediately before and after task performance was measured. The overall pattern of relationships between our measures supports the hypothesis that cortisol mobilization and ERN/Ne amplitude reflect task engagement, and both relate positively to each other and to the personality traits agreeableness and behavioral shame proneness. We discuss the potential importance of engagement-disengagement and of concerns over social evaluation for research on psychopathology, stress and the ERN/Ne.
A Bayesian approach to strengthen inference for case-control studies with multiple error-prone exposure assessments.
Zhang, Jing; Cole, Stephen R; Richardson, David B; Chu, Haitao
In case-control studies, exposure assessments are almost always error-prone. In the absence of a gold standard, two or more assessment approaches are often used to classify people with respect to exposure. Each imperfect assessment tool may lead to misclassification of exposure assignment; the exposure misclassification may be differential with respect to case status or not; and, the errors in exposure classification under the different approaches may be independent (conditional upon the true exposure status) or not. Although methods have been proposed to study diagnostic accuracy in the absence of a gold standard, these methods are infrequently used in case-control studies to correct exposure misclassification that is simultaneously differential and dependent. In this paper, we proposed a Bayesian method to estimate the measurement-error corrected exposure-disease association, accounting for both differential and dependent misclassification. The performance of the proposed method is investigated using simulations, which show that the proposed approach works well, as well as an application to a case-control study assessing the association between asbestos exposure and mesothelioma.
De novo centriole formation in human cells is error-prone and does not require SAS-6 self-assembly.
Wang, Won-Jing; Acehan, Devrim; Kao, Chien-Han; Jane, Wann-Neng; Uryu, Kunihiro; Tsou, Meng-Fu Bryan
Vertebrate centrioles normally propagate through duplication, but in the absence of preexisting centrioles, de novo synthesis can occur. Consistently, centriole formation is thought to strictly rely on self-assembly, involving self-oligomerization of the centriolar protein SAS-6. Here, through reconstitution of de novo synthesis in human cells, we surprisingly found that normal looking centrioles capable of duplication and ciliation can arise in the absence of SAS-6 self-oligomerization. Moreover, whereas canonically duplicated centrioles always form correctly, de novo centrioles are prone to structural errors, even in the presence of SAS-6 self-oligomerization. These results indicate that centriole biogenesis does not strictly depend on SAS-6 self-assembly, and may require preexisting centrioles to ensure structural accuracy, fundamentally deviating from the current paradigm.
A model for triplet mutation formation based on error-prone translesional DNA synthesis opposite UV photolesions.
Ikehata, Hironobu; Ono, Tetsuya; Tanaka, Kiyoji; Todo, Takeshi
A triplet mutation is defined as multiple base substitutions or frameshifts within a three-nucleotide sequence which includes a dipyrimidine sequence. Triplet mutations have recently been identified as a new type of UV-specific mutation, although the mechanism of their formation is unknown. A total of 163 triplet mutations were identified through an extensive search of previously published data on UV-induced mutations, including mutations from skin, skin cancer, and cultured mammalian cells. Seven common patterns of sequence changes were found: Type I, NTC-->TTT; Type IIa, NCC-->PyTT or PyCT (Py, pyrimidine); Type IIb, TCC-->PuTT or PuCT (Pu, purine); Type III, NCC-->NAT or NTA; Type IV, NTT-->AAT; Type Va, NCT-->NTX; and Type Vb, PuCT-->XTT (N and X, independent anonymous bases). Furthermore, it is suggested that the type of UV lesion responsible for each of these triplet mutation classes are (a) pyrimidine(6-4)pyrimidone photoproducts for Types I, IIb, III, IV and Vb, (b) cyclobutane pyrimidine dimers for Type Va, and (c) Dewar valence isomers for Types IIa and IIb. These estimations are based primarily on results from previous studies using photolyases specific for each type of UV lesion. A model is proposed to explain the formation of each type of triplet mutation, based on error-prone translesional DNA synthesis opposite UV-specific photolesions. The model is largely consistent with the 'A-rule', and predicts error-prone insertions not only opposite photolesions but also opposite the undamaged template base one-nucleotide downstream from the lesions.
A Nucleotide-Analogue-Induced Gain of Function Corrects the Error-Prone Nature of Human DNA Polymerase iota
Ketkar, Amit; Zafar, Maroof K.; Banerjee, Surajit; Marquez, Victor E.; Egli, Martin; Eoff, Robert L.
Y-family DNA polymerases participate in replication stress and DNA damage tolerance mechanisms. The properties that allow these enzymes to copy past bulky adducts or distorted template DNA can result in a greater propensity for them to make mistakes. Of the four human Y-family members, human DNA polymerase iota (hpol{iota}) is the most error-prone. In the current study, we elucidate the molecular basis for improving the fidelity of hpol{iota} through use of the fixed-conformation nucleotide North-methanocarba-2{prime}-deoxyadenosine triphosphate (N-MC-dATP). Three crystal structures were solved of hpol{iota} in complex with DNA containing a template 2{prime}-deoxythymidine (dT) paired with an incoming dNTP or modified nucleotide triphosphate. The ternary complex of hpol{iota} inserting N-MC-dATP opposite dT reveals that the adenine ring is stabilized in the anti orientation about the pseudo-glycosyl torsion angle, which mimics precisely the mutagenic arrangement of dGTP:dT normally preferred by hpol{iota}. The stabilized anti conformation occurs without notable contacts from the protein but likely results from constraints imposed by the bicyclo[3.1.0]hexane scaffold of the modified nucleotide. Unmodified dATP and South-MC-dATP each adopt syn glycosyl orientations to form Hoogsteen base pairs with dT. The Hoogsteen orientation exhibits weaker base-stacking interactions and is less catalytically favorable than anti N-MC-dATP. Thus, N-MC-dATP corrects the error-prone nature of hpol{iota} by preventing the Hoogsteen base-pairing mode normally observed for hpol{iota}-catalyzed insertion of dATP opposite dT. These results provide a previously unrecognized means of altering the efficiency and the fidelity of a human translesion DNA polymerase.
The DNA Ligase IV Syndrome R278H Mutation Impairs B Lymphopoiesis via Error-Prone Nonhomologous End-Joining.
Park, Jihye; Welner, Robert S; Chan, Mei-Yee; Troppito, Logan; Staber, Philipp B; Tenen, Daniel G; Yan, Catherine T
Hypomorphic mutations in the nonhomologous end-joining (NHEJ) DNA repair protein DNA ligase IV (LIG4) lead to immunodeficiency with varying severity. In this study, using a murine knock-in model, we investigated the mechanisms underlying abnormalities in class switch recombination (CSR) associated with the human homozygous Lig4 R278H mutation. Previously, we found that despite the near absence of Lig4 end-ligation activity and severely reduced mature B cell numbers, Lig4(R278H/R278H) (Lig4(R/R)) mice exhibit only a partial CSR block, producing near normal IgG1 and IgE but substantially reduced IgG3, IgG2b, and IgA serum levels. In this study, to address the cause of these abnormalities, we assayed CSR in Lig4(R/R) B cells generated via preassembled IgH and IgK V region exons (HL). This revealed that Lig4(R278H) protein levels while intact exhibited a higher turnover rate during activation of switching to IgG3 and IgG2b, as well as delays in CSR kinetics associated with defective proliferation during activation of switching to IgG1 and IgE. Activated Lig4(R/R)HL B cells consistently accumulated high frequencies of activation-induced cytidine deaminase-dependent IgH locus chromosomal breaks and translocations and were more prone to apoptosis, effects that appeared to be p53-independent, as p53 deficiency did not markedly influence these events. Importantly, NHEJ instead of alternative end-joining (A-EJ) was revealed as the predominant mechanism catalyzing robust CSR. Defective CSR was linked to failed NHEJ and residual A-EJ access to unrepaired double-strand breaks. These data firmly demonstrate that Lig4(R278H) activity renders NHEJ to be more error-prone, and they predict increased error-prone NHEJ activity and A-EJ suppression as the cause of the defective B lymphopoiesis in Lig4 patients.
A comparison of two multiple access schemes for satellite networks with error-prone transmission channels
NASA Astrophysics Data System (ADS)
Boettcher, Axel; Dippold, Michael
Multiple access to the radio channel is an important feature for the efficiency of satellite packet data networks. In the case of mobile stations communicating via satellite, which is the scope of this paper, the performance of the various channel access methods is degraded by transmission errors due to multipath propagation and signal shadowing. Using the same channel and user models and the same method of analysis, the performance of two typical access schemes from different classes is compared: Slotted Aloha and a demand assignment (DAMA) technique. Slotted Aloha exhibits less delay than DAMA for a moderate data traffic, but DAMA supports more data traffic when the link quality is good. Under the influence of shadowing on the channel, Slotted Aloha degrades more slowly than DAMA due to the capture-effect.
The Preference for Error-Free or Error-Prone Postreplication Repair in Saccharomyces cerevisiae Exposed to Low-Dose Methyl Methanesulfonate Is Cell Cycle Dependent
Huang, Dongqing; Piening, Brian D.
Cells employ error-free or error-prone postreplication repair (PRR) processes to tolerate DNA damage. Here, we present a genome-wide screen for sensitivity to 0.001% methyl methanesulfonate (MMS). This relatively low dose is of particular interest because wild-type cells exhibit no discernible phenotypes in response to treatment, yet PRR mutants are unique among repair mutants in their exquisite sensitivity to 0.001% MMS; thus, low-dose MMS treatment provides a distinctive opportunity to study postreplication repair processes. We show that upon exposure to low-dose MMS, a PRR-defective rad18Δ mutant stalls into a lengthy G2 arrest associated with the accumulation of single-stranded DNA (ssDNA) gaps. Consistent with previous results following UV-induced damage, reactivation of Rad18, even after prolonged G2 arrest, restores viability and genome integrity. We further show that PRR pathway preference in 0.001% MMS depends on timing and context; cells preferentially employ the error-free pathway in S phase and do not require MEC1-dependent checkpoint activation for survival. However, when PRR is restricted to the G2 phase, cells utilize REV3-dependent translesion synthesis, which requires a MEC1-dependent delay and results in significant hypermutability. PMID:23382077
UmuDAb: An Error-Prone Polymerase Accessory Homolog Whose N-Terminal Domain Is Required for Repression of DNA Damage Inducible Gene Expression in Acinetobacter baylyi
Stinnett, DeAnna B.; Wells, Whitney K.; Peterson, Megan A.; Hare, Janelle M.
In many bacteria, the DNA damage response induces genes (SOS genes) that were repressed by LexA. LexA represses transcription by binding to SOS promoters via a helix-turn-helix motif in its N-terminal domain (NTD). Upon DNA damage, LexA cleaves itself and allows induction of transcription. In Acinetobacter baumannii and Acinetobacter baylyi, multiple genes are induced by DNA damage, and although the Acinetobacter genus lacks LexA, a homolog of the error-prone polymerase subunit UmuD, called UmuDAb, regulates some DNA damage-induced genes. The mechanism of UmuDAb regulation has not been determined. We constructed UmuDAb mutant strains of A. baylyi to test whether UmuDAb mediates gene regulation through LexA-like repressor actions consisting of relief of repression through self-cleavage after DNA damage. Real-time quantitative PCR experiments in both a null umuDAb mutant and an NTD mutant showed that the DNA damage-inducible, UmuDAb-regulated gene ddrR was highly expressed even in the absence of DNA damage. Protein modeling identified a potential LexA-like helix-turn-helix structure in the UmuDAb NTD, which when disrupted, also relieved ddrR and umuDAb repression under non-inducing conditions. Mutations in a putative SOS box in the shared umuDAb-ddrR promoter region similarly relieved these genes' repression under non-inducing conditions. Conversely, cells possessing a cleavage-deficient UmuDAb were unable to induce gene expression after MMC-mediated DNA damage. This evidence of a UmuDAb repressor mechanism was contrasted with the failure of umuDAb to complement an Escherichia coli umuD mutant for UmuD error-prone DNA replication activity. Similarly, A. baumannii null umuDAb mutant cells did not have a reduced UmuDˊ2UmuC-mediated mutation rate after DNA damage, suggesting that although this UmuDAb protein may have evolved from a umuDC operon in this genus, it now performs a LexA-like repressor function for a sub-set of DNA damage-induced genes. PMID:27010837
UmuDAb: An Error-Prone Polymerase Accessory Homolog Whose N-Terminal Domain Is Required for Repression of DNA Damage Inducible Gene Expression in Acinetobacter baylyi.
Witkowski, Travis A; Grice, Alison N; Stinnett, DeAnna B; Wells, Whitney K; Peterson, Megan A; Hare, Janelle M
In many bacteria, the DNA damage response induces genes (SOS genes) that were repressed by LexA. LexA represses transcription by binding to SOS promoters via a helix-turn-helix motif in its N-terminal domain (NTD). Upon DNA damage, LexA cleaves itself and allows induction of transcription. In Acinetobacter baumannii and Acinetobacter baylyi, multiple genes are induced by DNA damage, and although the Acinetobacter genus lacks LexA, a homolog of the error-prone polymerase subunit UmuD, called UmuDAb, regulates some DNA damage-induced genes. The mechanism of UmuDAb regulation has not been determined. We constructed UmuDAb mutant strains of A. baylyi to test whether UmuDAb mediates gene regulation through LexA-like repressor actions consisting of relief of repression through self-cleavage after DNA damage. Real-time quantitative PCR experiments in both a null umuDAb mutant and an NTD mutant showed that the DNA damage-inducible, UmuDAb-regulated gene ddrR was highly expressed even in the absence of DNA damage. Protein modeling identified a potential LexA-like helix-turn-helix structure in the UmuDAb NTD, which when disrupted, also relieved ddrR and umuDAb repression under non-inducing conditions. Mutations in a putative SOS box in the shared umuDAb-ddrR promoter region similarly relieved these genes' repression under non-inducing conditions. Conversely, cells possessing a cleavage-deficient UmuDAb were unable to induce gene expression after MMC-mediated DNA damage. This evidence of a UmuDAb repressor mechanism was contrasted with the failure of umuDAb to complement an Escherichia coli umuD mutant for UmuD error-prone DNA replication activity. Similarly, A. baumannii null umuDAb mutant cells did not have a reduced UmuD'2UmuC-mediated mutation rate after DNA damage, suggesting that although this UmuDAb protein may have evolved from a umuDC operon in this genus, it now performs a LexA-like repressor function for a sub-set of DNA damage-induced genes.
Quality Control Analysis of Selected Aspects of Programs Administered by the Bureau of Student Financial Assistance. Task 1 and Quality Control Sample; Error-Prone Modeling Analysis Plan.
ERIC Educational Resources Information Center
Saavedra, Pedro; And Others
Parameters and procedures for developing an error-prone model (EPM) to predict financial aid applicants who are likely to misreport on Basic Educational Opportunity Grant (BEOG) applications are introduced. Specifications to adapt these general parameters to secondary data analysis of the Validation, Edits, and Applications Processing Systems…
Multiple point mutations in a shuttle vector propagated in human cells: evidence for an error-prone DNA polymerase activity
Seidman, M.M.; Bredberg, A.; Seetharam, S.; Kraemer, K.H.
Mutagenesis was studied at the DNA-sequence level in human fibroblast and lymphoid cells by use of a shuttle vector plasmid, pZ189, containing a suppressor tRNA marker gene. In a series of experiments, 62 plasmids were recovered that had two to six base substitutions in the 160-base-pair marker gene. Approximately 20-30% of the mutant plasmids that were recovered after passing ultraviolet-treated pZ189 through a repair-proficient human fibroblast line contained these multiple mutations. In contrast, passage of ultraviolet-treated pZ189 through an excision-repair-deficient (xeroderma pigmentosum) line yielded only 2% multiple base substitution mutants. Introducing a single-strand nick in otherwise unmodified pZ189 adjacent to the marker, followed by passage through the xeroderma pigmentosum cells, resulted in about 66% multiple base substitution mutants. The multiple mutations were found in a 160-base-pair region containing the marker gene but were rarely found in an adjacent 170-base-pair region. Passing ultraviolet-treated or nicked pZ189 through a repair-proficient human B-cell line also yielded multiple base substitution mutations in 20-33% of the mutant plasmids. An explanation for these multiple mutations is that they were generated by an error-prone polymerase while filling gaps. These mutations share many of the properties displayed by mutations in the immunoglobulin hypervariable regions.
Error-prone ZW pairing and no evidence for meiotic sex chromosome inactivation in the chicken germ line.
Guioli, Silvana; Lovell-Badge, Robin; Turner, James M A
In the male mouse the X and Y chromosomes pair and recombine within the small pseudoautosomal region. Genes located on the unsynapsed segments of the X and Y are transcriptionally silenced at pachytene by Meiotic Sex Chromosome Inactivation (MSCI). The degree to which MSCI is conserved in other vertebrates is currently unclear. In the female chicken the ZW bivalent is thought to undergo a transient phase of full synapsis at pachytene, starting from the homologous ends and spreading through the heterologous regions. It has been proposed that the repair of the ZW DNA double-strand breaks (DSBs) is postponed until diplotene and that the ZW bivalent is subject to MSCI, which is independent of its synaptic status. Here we present a distinct model of meiotic pairing and silencing of the ZW pair during chicken oogenesis. We show that, in most oocytes, DNA DSB foci on the ZW are resolved by the end of pachytene and that the ZW desynapses in broad synchrony with the autosomes. We unexpectedly find that ZW pairing is highly error prone, with many oocytes failing to engage in ZW synapsis and crossover formation. Oocytes with unsynapsed Z and W chromosomes nevertheless progress to the diplotene stage, suggesting that a checkpoint does not operate during pachytene in the chicken germ line. Using a combination of epigenetic profiling and RNA-FISH analysis, we find no evidence for MSCI, associated with neither the asynaptic ZW, as described in mammals, nor the synaptic ZW. The lack of conservation of MSCI in the chicken reopens the debate about the evolution of MSCI and its driving forces.
Biochemical analysis of six genetic variants of error-prone human DNA polymerase ι involved in translesion DNA synthesis.
Kim, Jinsook; Song, Insil; Jo, Ara; Shin, Joo-Ho; Cho, Hana; Eoff, Robert L; Guengerich, F Peter; Choi, Jeong-Yun
DNA polymerase (pol) ι is the most error-prone among the Y-family polymerases that participate in translesion synthesis (TLS). Pol ι can bypass various DNA lesions, e.g., N(2)-ethyl(Et)G, O(6)-methyl(Me)G, 8-oxo-7,8-dihydroguanine (8-oxoG), and an abasic site, though frequently with low fidelity. We assessed the biochemical effects of six reported genetic variations of human pol ι on its TLS properties, using the recombinant pol ι (residues 1-445) proteins and DNA templates containing a G, N(2)-EtG, O(6)-MeG, 8-oxoG, or abasic site. The Δ1-25 variant, which is the N-terminal truncation of 25 residues resulting from an initiation codon variant (c.3G > A) and also is the formerly misassigned wild-type, exhibited considerably higher polymerase activity than wild-type with Mg(2+) (but not with Mn(2+)), coinciding with its steady-state kinetic data showing a ∼10-fold increase in kcat/Km for nucleotide incorporation opposite templates (only with Mg(2+)). The R96G variant, which lacks a R96 residue known to interact with the incoming nucleotide, lost much of its polymerase activity, consistent with the kinetic data displaying 5- to 72-fold decreases in kcat/Km for nucleotide incorporation opposite templates either with Mg(2+) or Mn(2+), except for that opposite N(2)-EtG with Mn(2+) (showing a 9-fold increase for dCTP incorporation). The Δ1-25 variant bound DNA 20- to 29-fold more tightly than wild-type (with Mg(2+)), but the R96G variant bound DNA 2-fold less tightly than wild-type. The DNA-binding affinity of wild-type, but not of the Δ1-25 variant, was ∼7-fold stronger with 0.15 mM Mn(2+) than with Mg(2+). The results indicate that the R96G variation severely impairs most of the Mg(2+)- and Mn(2+)-dependent TLS abilities of pol ι, whereas the Δ1-25 variation selectively and substantially enhances the Mg(2+)-dependent TLS capability of pol ι, emphasizing the potential translational importance of these pol ι genetic variations, e.g., individual differences
Saccharomyces cerevisiae Ku70 potentiates illegitimate DNA double-strand break repair and serves as a barrier to error-prone DNA repair pathways.
Boulton, S J; Jackson, S P
Ku, a heterodimer of polypeptides of approximately 70 kDa and 80 kDa (Ku70 and Ku80, respectively), binds avidly to DNA double-strand breaks (DSBs). Mammalian cells defective in Ku are hypersensitive to ionizing radiation due to a deficiency in DSB repair. Here, we show that the simple inactivation of the Saccharomyces cerevisiae Ku70 homologue (Yku70p), does not lead to increased radiosensitivity. However, yku70 mutations enhance the radiosensitivity of rad52 strains, which are deficient in homologous recombination. Through establishing a rapid and reproducible in vivo plasmid rejoining assay, we show that Yku70p plays a crucial role in the repair of DSBs bearing cohesive termini. Whereas this damage is repaired accurately in YKU70 backgrounds, in yku70 mutant strains terminal deletions of up to several hundred bp occur before ligation ensues. Interestingly, this error-prone DNA repair pathway utilizes short homologies between the two recombining molecules and is thus highly reminiscent of a predominant form of DSB repair that operates in vertebrates. These data therefore provide evidence for two distinct and evolutionarily conserved illegitimate recombination pathways. One of these is accurate and Yku70p-dependent, whereas the other is error-prone and Yku70-independent. Furthermore, our studies suggest that Yku70 promotes genomic stability both by promoting accurate DNA repair and by serving as a barrier to error-prone repair processes. Images PMID:8890183
Examining Sources of Error in PCR by Single-Molecule Sequencing
Potapov, Vladimir
Next-generation sequencing technology has enabled the detection of rare genetic or somatic mutations and contributed to our understanding of disease progression and evolution. However, many next-generation sequencing technologies first rely on DNA amplification, via the Polymerase Chain Reaction (PCR), as part of sample preparation workflows. Mistakes made during PCR appear in sequencing data and contribute to false mutations that can ultimately confound genetic analysis. In this report, a single-molecule sequencing assay was used to comprehensively catalog the different types of errors introduced during PCR, including polymerase misincorporation, structure-induced template-switching, PCR-mediated recombination and DNA damage. In addition to well-characterized polymerase base substitution errors, other sources of error were found to be equally prevalent. PCR-mediated recombination by Taq polymerase was observed at the single-molecule level, and surprisingly found to occur as frequently as polymerase base substitution errors, suggesting it may be an underappreciated source of error for multiplex amplification reactions. Inverted repeat structural elements in lacZ caused polymerase template-switching between the top and bottom strands during replication and the frequency of these events were measured for different polymerases. For very accurate polymerases, DNA damage introduced during temperature cycling, and not polymerase base substitution errors, appeared to be the major contributor toward mutations occurring in amplification products. In total, we analyzed PCR products at the single-molecule level and present here a more complete picture of the types of mistakes that occur during DNA amplification. PMID:28060945
Use of damaged DNA and dNTP substrates by the error-prone DNA polymerase X from African swine fever virus.
Kumar, Sandeep; Lamarche, Brandon J; Tsai, Ming-Daw
The structural specificity that translesion DNA polymerases often show for a particular class of lesions suggests that the predominant criterion of selection during their evolution has been the capacity for lesion tolerance and that the error-proneness they display when copying undamaged templates may simply be a byproduct of this adaptation. Regardless of selection criteria/evolutionary history, at present both of these properties coexist in these enzymes, and both properties confer a fitness advantage. The repair polymerase, Pol X, encoded by the African swine fever virus (ASFV) is one of the most error-prone polymerases known, leading us to previously hypothesize that it may work in tandem with the exceptionally error-tolerant ASFV DNA ligase to effect viral mutagenesis. Here, for the first time, we test whether the error-proneness of Pol X is coupled with a capacity for lesion tolerance by examining its ability to utilize the types of damaged DNA and dNTP substrates that are expected to be relevant to ASFV. We (i) test Pol X's ability to both incorporate opposite to and extend from ubiquitous oxidative purine (7,8-dihydro-8-oxoguanine), oxidative pyrimidine (5,6-dihydroxy-5,6-dihydrothymine), and noncoding (AP site) lesions, in addition to 5,6-dihydrothymine, (ii) determine the catalytic efficiency and dNTP specificity of Pol X when catalyzing incorporation opposite to, and when extending from, 7,8-dihydro-8-oxoguanine in a template/primer context, and (iii) quantitate Pol X-catalyzed incorporation of the damaged nucleotide 8-oxo-dGTP opposite to undamaged templates in the context of both template/primer and a single-nucleotide gap. Our findings are discussed in light of ASFV biology and the mutagenic DNA repair hypothesis described above.
Structural and Functional Elucidation of the Mechanism Promoting Error-prone Synthesis by Human DNA Polymerase [kappa] Opposite the 7,8-Dihydro-8-oxo-2'-deoxyguanosine Adduct
Irimia, Adriana; Eoff, Robert L.; Guengerich, F.Peter; Egli, Martin
Human polymerase kappa (hPol {kappa}) is one of four eukaryotic Y-class DNA polymerases and may be an important element in the cellular response to polycyclic aromatic hydrocarbons such as benzo[a]pyrene, which can lead to reactive oxygenated metabolite-mediated oxidative stress. Here, we present a detailed analysis of the activity and specificity of hPol {kappa} bypass opposite the major oxidative adduct 7,8-dihydro-8-oxo-2{prime}-deoxyguanosine (8-oxoG). Unlike its archaeal homolog Dpo4, hPol {kappa} bypasses this lesion in an error-prone fashion by inserting mainly dATP. Analysis of transient-state kinetics shows diminished 'bursts' for dATP:8-oxoG and dCTP:8-oxoG incorporation, indicative of non-productive complex formation, but dATP:8-oxoG insertion events that do occur are 2-fold more efficient than dCTP:G insertion events. Crystal structures of ternary hPol {kappa} complexes with adducted template-primer DNA reveal non-productive (dGTP and dATP) alignments of incoming nucleotide and 8-oxoG. Structural limitations placed upon the hPol {kappa} by interactions between the N-clasp and finger domains combined with stabilization of the syn-oriented template 8-oxoG through the side chain of Met-135 both appear to contribute to error-prone bypass. Mutating Leu-508 in the little finger domain of hPol {kappa} to lysine modulates the insertion opposite 8-oxoG toward more accurate bypass, similar to previous findings with Dpo4. Our structural and activity data provide insight into important mechanistic aspects of error-prone bypass of 8-oxoG by hPol {kappa} compared with accurate and efficient bypass of the lesion by Dpo4 and polymerase {eta}.
Differential expression of APE1 and APE2 in germinal centers promotes error-prone repair and A:T mutations during somatic hypermutation.
Stavnezer, Janet; Linehan, Erin K; Thompson, Mikayla R; Habboub, Ghaith; Ucher, Anna J; Kadungure, Tatenda; Tsuchimoto, Daisuke; Nakabeppu, Yusaku; Schrader, Carol E
Somatic hypermutation (SHM) of antibody variable region genes is initiated in germinal center B cells during an immune response by activation-induced cytidine deaminase (AID), which converts cytosines to uracils. During accurate repair in nonmutating cells, uracil is excised by uracil DNA glycosylase (UNG), leaving abasic sites that are incised by AP endonuclease (APE) to create single-strand breaks, and the correct nucleotide is reinserted by DNA polymerase β. During SHM, for unknown reasons, repair is error prone. There are two APE homologs in mammals and, surprisingly, APE1, in contrast to its high expression in both resting and in vitro-activated splenic B cells, is expressed at very low levels in mouse germinal center B cells where SHM occurs, and APE1 haploinsufficiency has very little effect on SHM. In contrast, the less efficient homolog, APE2, is highly expressed and contributes not only to the frequency of mutations, but also to the generation of mutations at A:T base pair (bp), insertions, and deletions. In the absence of both UNG and APE2, mutations at A:T bp are dramatically reduced. Single-strand breaks generated by APE2 could provide entry points for exonuclease recruited by the mismatch repair proteins Msh2-Msh6, and the known association of APE2 with proliferating cell nuclear antigen could recruit translesion polymerases to create mutations at AID-induced lesions and also at A:T bp. Our data provide new insight into error-prone repair of AID-induced lesions, which we propose is facilitated by down-regulation of APE1 and up-regulation of APE2 expression in germinal center B cells.
Rapid and apparently error-prone excision repair of nonreplicating UV-irradiated plasmids in Xenopus laevis oocytes
Hays, J.B.; Ackerman, E.J.; Pang, Q.S. )
Repair of UV-irradiated plasmid DNA microinjected into frog oocytes was measured by two techniques: transformation of repair-deficient (delta uvrB delta recA delta phr) bacteria, and removal of UV endonuclease-sensitive sites (ESS). Transformation efficiencies relative to unirradiated plasmids were used to estimate the number of lethal lesions; the latter were assumed to be Poisson distributed. These estimates were in good agreement with measurements of ESS. By both criteria, plasmid DNA was efficiently repaired, mostly during the first 2 h, when as many as 2 x 10(10) lethal lesions were removed per oocyte. This rate is about 10(6) times the average for removal of ESS from repair-proficient human cells. Repair was slower but still significant after 2 h, but some lethal lesions usually remained after overnight incubation. Most repair occurred in the absence of light, in marked contrast to differentiated frog cells, previously shown to possess photoreactivating but no excision repair activity. There was no increase in the resistance to DpnI restriction of plasmids (methylated in Escherichia coli at GATC sites) incubated in oocytes; this implies no increase in hemimethylated GATC sites, and hence no semiconservative DNA replication. Plasmid substrates capable of either intramolecular or intermolecular homologous recombination were not recombined, whether UV-irradiated or not. Repair of Lac+ plasmids was accompanied by a significant UV-dependent increase in the frequency of Lac- mutants, corresponding to a repair synthesis error frequency on the order of 10(-4) per nucleotide.
Dissociation rate of cognate peptidyl-tRNA from the A-site of hyper-accurate and error-prone ribosomes.
Karimi, R; Ehrenberg, M
The binding stability of the aminoacyl-tRNA site (A-site), estimated from the dissociation rate constant kd, of AcPhe-Phe-tRNA(Phe) has been studied for wild-type (wt), for hyperaccurate ribosomes altered in S12 [streptomycin-dependent (SmD) and streptomycin-pseudodependent (SmP) phenotypes], for error-prone ribosomes altered in S4 (Ram phenotype), and for ribosomes in complex with the error-inducing aminoglycosides streptomycin and neomycin. The AcPhe2-tRNA stability is slightly and identically reduced for SmD and SmP phenotypes in relation to wt ribosomes. The stability is increased (kd is reduced) for Ram ribosomes to about the same extent as the proof-reading accuracy is decreased for this phenotype. kd is also reduced by the action of streptomycin and neomycin, but much less than the reduction in proof-reading accuracy induced by streptomycin. Similar kd values for SmD and SmP ribosomes indicate that the cause of streptomycin dependence is not excessive drop-off of peptidyl-tRNAs from the A-site.
The Error-Prone DNA Polymerase κ Promotes Temozolomide Resistance in Glioblastoma through Rad17-Dependent Activation of ATR-Chk1 Signaling.
Peng, Chenghao; Chen, Zhengxin; Wang, Shuai; Wang, Hong-Wei; Qiu, Wenjin; Zhao, Lin; Xu, Ran; Luo, Hui; Chen, Yuanyuan; Chen, Dan; You, Yongping; Liu, Ning; Wang, Huibo
The acquisition of drug resistance is a persistent clinical problem limiting the successful treatment of human cancers, including glioblastoma (GBM). However, the molecular mechanisms by which initially chemoresponsive tumors develop therapeutic resistance remain poorly understood. In this study, we report that Pol κ, an error-prone polymerase that participates in translesion DNA synthesis, was significantly upregulated in GBM cell lines and tumor tissues following temozolomide treatment. Overexpression of Pol κ in temozolomide-sensitive GBM cells conferred resistance to temozolomide, whereas its inhibition markedly sensitized resistant cells to temozolomide in vitro and in orthotopic xenograft mouse models. Mechanistically, depletion of Pol κ disrupted homologous recombination (HR)-mediated repair and restart of stalled replication forks, impaired the activation of ATR-Chk1 signaling, and delayed cell-cycle re-entry and progression. Further investigation of the relationship between Pol κ and temozolomide revealed that Pol κ inactivation facilitated temozolomide-induced Rad17 ubiquitination and proteasomal degradation, subsequently silencing ATR-Chk1 signaling and leading to defective HR repair and the reversal of temozolomide resistance. Moreover, overexpression of Rad17 in Pol κ-depleted GBM cells restored HR efficiency, promoted the clearance of temozolomide-induced DNA breaks, and desensitized cells to the cytotoxic effects of temozolomide observed in the absence of Pol κ. Finally, we found that Pol κ overexpression correlated with poor prognosis in GBM patients undergoing temozolomide therapy. Collectively, our findings identify a potential mechanism by which GBM cells develop resistance to temozolomide and suggest that targeting the DNA damage tolerance pathway may be beneficial for overcoming resistance. Cancer Res; 76(8); 2340-53. ©2016 AACR.
The Werner syndrome protein limits the error-prone 8-oxo-dG lesion bypass activity of human DNA polymerase kappa
Maddukuri, Leena; Ketkar, Amit; Eddy, Sarah; Zafar, Maroof K.; Eoff, Robert L.
Human DNA polymerase kappa (hpol κ) is the only Y-family member to preferentially insert dAMP opposite 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dG) during translesion DNA synthesis. We have studied the mechanism of action by which hpol κ activity is modulated by the Werner syndrome protein (WRN), a RecQ helicase known to influence repair of 8-oxo-dG. Here we show that WRN stimulates the 8-oxo-dG bypass activity of hpol κ in vitro by enhancing the correct base insertion opposite the lesion, as well as extension from dC:8-oxo-dG base pairs. Steady-state kinetic analysis reveals that WRN improves hpol κ-catalyzed dCMP insertion opposite 8-oxo-dG ∼10-fold and extension from dC:8-oxo-dG by 2.4-fold. Stimulation is primarily due to an increase in the rate constant for polymerization (kpol), as assessed by pre-steady-state kinetics, and it requires the RecQ C-terminal (RQC) domain. In support of the functional data, recombinant WRN and hpol κ were found to physically interact through the exo and RQC domains of WRN, and co-localization of WRN and hpol κ was observed in human cells treated with hydrogen peroxide. Thus, WRN limits the error-prone bypass of 8-oxo-dG by hpol κ, which could influence the sensitivity to oxidative damage that has previously been observed for Werner's syndrome cells. PMID:25294835
The Werner syndrome protein limits the error-prone 8-oxo-dG lesion bypass activity of human DNA polymerase kappa.
Maddukuri, Leena; Ketkar, Amit; Eddy, Sarah; Zafar, Maroof K; Eoff, Robert L
Human DNA polymerase kappa (hpol κ) is the only Y-family member to preferentially insert dAMP opposite 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG) during translesion DNA synthesis. We have studied the mechanism of action by which hpol κ activity is modulated by the Werner syndrome protein (WRN), a RecQ helicase known to influence repair of 8-oxo-dG. Here we show that WRN stimulates the 8-oxo-dG bypass activity of hpol κ in vitro by enhancing the correct base insertion opposite the lesion, as well as extension from dC:8-oxo-dG base pairs. Steady-state kinetic analysis reveals that WRN improves hpol κ-catalyzed dCMP insertion opposite 8-oxo-dG ∼10-fold and extension from dC:8-oxo-dG by 2.4-fold. Stimulation is primarily due to an increase in the rate constant for polymerization (kpol), as assessed by pre-steady-state kinetics, and it requires the RecQ C-terminal (RQC) domain. In support of the functional data, recombinant WRN and hpol κ were found to physically interact through the exo and RQC domains of WRN, and co-localization of WRN and hpol κ was observed in human cells treated with hydrogen peroxide. Thus, WRN limits the error-prone bypass of 8-oxo-dG by hpol κ, which could influence the sensitivity to oxidative damage that has previously been observed for Werner's syndrome cells.
miR-155 Over-expression Promotes Genomic Instability by Reducing High-fidelity Polymerase Delta Expression and Activating Error-prone DSB Repair
Czochor, Jennifer R.; Sulkowski, Parker; Glazer, Peter M.
miR-155 is an oncogenic microRNA (miR) that is often over-expressed in cancer and is associated with poor prognosis. miR-155 can target several DNA repair factors including RAD51, MLH1, and MSH6, and its over-expression results in an increased mutation frequency in vitro, although the mechanism has yet to be fully understood. Here, we demonstrate that over-expression of miR-155 drives an increased mutation frequency both in vitro and in vivo, promoting genomic instability by affecting multiple DNA repair pathways. miR-155 over-expression causes a decrease in homologous recombination, but yields a concurrent increase in the error-prone non-homologous end-joining (NHEJ) pathway. Despite repressing established targets MLH1 and MSH6, the identified mutation pattern upon miR-155 over-expression does not resemble that of a mismatch repair-deficient background. Further investigation revealed that all four subunits of polymerase delta, a high-fidelity DNA replication and repair polymerase, are down-regulated at the mRNA level in the context of miR-155 over-expression. FOXO3a, a transcription factor and known target of miR-155, has one or more putative binding site(s) in the promoter of all four polymerase delta subunits. Finally, suppression of FOXO3a by miR-155 or by siRNA knockdown is sufficient to repress the expression of the catalytic subunit of polymerase delta, POLD1, at the protein level, indicating that FOXO3a contributes to the regulation of polymerase delta levels. PMID:26850462
LEMming: A Linear Error Model to Normalize Parallel Quantitative Real-Time PCR (qPCR) Data as an Alternative to Reference Gene Based Methods
Feuer, Ronny; Vlaic, Sebastian; Arlt, Janine; Sawodny, Oliver; Dahmen, Uta; Zanger, Ulrich M.; Thomas, Maria
Background Gene expression analysis is an essential part of biological and medical investigations. Quantitative real-time PCR (qPCR) is characterized with excellent sensitivity, dynamic range, reproducibility and is still regarded to be the gold standard for quantifying transcripts abundance. Parallelization of qPCR such as by microfluidic Taqman Fluidigm Biomark Platform enables evaluation of multiple transcripts in samples treated under various conditions. Despite advanced technologies, correct evaluation of the measurements remains challenging. Most widely used methods for evaluating or calculating gene expression data include geNorm and ΔΔCt, respectively. They rely on one or several stable reference genes (RGs) for normalization, thus potentially causing biased results. We therefore applied multivariable regression with a tailored error model to overcome the necessity of stable RGs. Results We developed a RG independent data normalization approach based on a tailored linear error model for parallel qPCR data, called LEMming. It uses the assumption that the mean Ct values within samples of similarly treated groups are equal. Performance of LEMming was evaluated in three data sets with different stability patterns of RGs and compared to the results of geNorm normalization. Data set 1 showed that both methods gave similar results if stable RGs are available. Data set 2 included RGs which are stable according to geNorm criteria, but became differentially expressed in normalized data evaluated by a t-test. geNorm-normalized data showed an effect of a shifted mean per gene per condition whereas LEMming-normalized data did not. Comparing the decrease of standard deviation from raw data to geNorm and to LEMming, the latter was superior. In data set 3 according to geNorm calculated average expression stability and pairwise variation, stable RGs were available, but t-tests of raw data contradicted this. Normalization with RGs resulted in distorted data contradicting
Evidence from mutation spectra that the UV hypermutability of xeroderma pigmentosum variant cells reflects abnormal, error-prone replication on a template containing photoproducts.
Wang, Y C; Maher, V M; Mitchell, D L; McCormick, J J
Xeroderma pigmentosum (XP) variant patients are genetically predisposed to sunlight-induced skin cancer. Fibroblasts derived from these patients are extremely sensitive to the mutagenic effect of UV radiation and are abnormally slow in replicating DNA containing UV-induced photoproducts. However, unlike cells from the majority of XP patients, XP variant cells have a normal or nearly normal rate of nucleotide excision repair of such damage. To determine whether their UV hypermutability reflected a slower rate of excision of photoproducts specifically during early S phase when the target gene for mutations, i.e., the hypoxanthine (guanine) phosphoribosyltransferase gene (HPRT), is replicated, we synchronized diploid populations of normal and XP variant fibroblasts, irradiated them in early S phase, and compared the rate of loss of cyclobutane pyrimidine dimers and 6-4 pyrimidine-pyrimidones from DNA during S phase. There was no difference. Both removed 94% of the 6-4 pyrimidine-pyrimidones within 8 h and 40% of the dimers within 11 h. There was also no difference between the two cell lines in the rate of repair during G1 phase. To determine whether the hypermutability resulted from abnormal error-prone replication of DNA containing photoproducts, we determined the spectra of mutations induced in the coding region of the HPRT gene of XP variant cells irradiated in early S and G1 phases and compared with those found in normal cells. The majority of the mutations in both types of cells were base substitutions, but the two types of cells differed significantly from each other in the kinds of substitutions, but the two types differed significantly from each other in the kinds of substitutions observed either in mutants from S phase (P < 0.01) or from G1 phase (P = 0.03). In the variant cells, the substitutions were mainly transversions (58% in S, 73% in G1). In the normal cells irradiated in S, the majority of the substitutions were G.C --> A.T, and most involved CC
Error rates, PCR recombination, and sampling depth in HIV-1 whole genome deep sequencing.
Zanini, Fabio; Brodin, Johanna; Albert, Jan; Neher, Richard A
Deep sequencing is a powerful and cost-effective tool to characterize the genetic diversity and evolution of virus populations. While modern sequencing instruments readily cover viral genomes many thousand fold and very rare variants can in principle be detected, sequencing errors, amplification biases, and other artifacts can limit sensitivity and complicate data interpretation. For this reason, the number of studies using whole genome deep sequencing to characterize viral quasi-species in clinical samples is still limited. We have previously undertaken a large scale whole genome deep sequencing study of HIV-1 populations. Here we discuss the challenges, error profiles, control experiments, and computational test we developed to quantify the accuracy of variant frequency estimation.
DNA double-strand–break complexity levels and their possible contributions to the probability for error-prone processing and repair pathway choice
Schipler, Agnes; Iliakis, George
Although the DNA double-strand break (DSB) is defined as a rupture in the double-stranded DNA molecule that can occur without chemical modification in any of the constituent building blocks, it is recognized that this form is restricted to enzyme-induced DSBs. DSBs generated by physical or chemical agents can include at the break site a spectrum of base alterations (lesions). The nature and number of such chemical alterations define the complexity of the DSB and are considered putative determinants for repair pathway choice and the probability that errors will occur during this processing. As the pathways engaged in DSB processing show distinct and frequently inherent propensities for errors, pathway choice also defines the error-levels cells opt to accept. Here, we present a classification of DSBs on the basis of increasing complexity and discuss how complexity may affect processing, as well as how it may cause lethal or carcinogenic processing errors. By critically analyzing the characteristics of DSB repair pathways, we suggest that all repair pathways can in principle remove lesions clustering at the DSB but are likely to fail when they encounter clusters of DSBs that cause a local form of chromothripsis. In the same framework, we also analyze the rational of DSB repair pathway choice. PMID:23804754
The Concept of Accident Proneness: A Review
Froggatt, Peter; Smiley, James A.
The term accident proneness was coined by psychological research workers in 1926. Since then its concept—that certain individuals are always more likely than others to sustain accidents, even though exposed to equal risk—has been questioned but seldom seriously challenged. This article describes much of the work and theory on which this concept is based, details the difficulties encountered in obtaining valid information and the interpretative errors that can arise from the examination of imperfect data, and explains why accident proneness became so readily accepted as an explanation of the facts. A recent hypothesis of accident causation, namely that a person's accident liability may vary from time to time, is outlined, and the respective abilities of this and of accident proneness to accord with data from the more reliable literature are examined. The authors conclude that the hypothesis of individual variation in liability is more realistic and in better agreement with the data than is accident proneness. PMID:14106130
Upscaled CTAB-based DNA extraction and real-time PCR assays for Fusarium culmorum and F. graminearum DNA in plant material with reduced sampling error.
Brandfass, Christoph; Karlovsky, Petr
Fusarium graminearum Schwabe (Gibberella zeae Schwein. Petch.) and F. culmorum W.G. Smith are major mycotoxin producers in small-grain cereals afflicted with Fusarium head blight (FHB). Real-time PCR (qPCR) is the method of choice for species-specific, quantitative estimation of fungal biomass in plant tissue. We demonstrated that increasing the amount of plant material used for DNA extraction to 0.5-1.0 g considerably reduced sampling error and improved the reproducibility of DNA yield. The costs of DNA extraction at different scales and with different methods (commercial kits versus cetyltrimethylammonium bromide-based protocol) and qPCR systems (doubly labeled hybridization probes versus SYBR Green) were compared. A cost-effective protocol for the quantification of F. graminearum and F. culmorum DNA in wheat grain and maize stalk debris based on DNA extraction from 0.5-1.0 g material and real-time PCR with SYBR Green fluorescence detection was developed.
A false positive food chain error associated with a generic predator gut content ELISA
Technology Transfer Automated Retrieval System (TEKTRAN)
Conventional prey-specific gut content ELISA and PCR assays are useful for identifying predators of insect pests in nature. However, these assays are prone to yielding certain types of food chain errors. For instance, it is possible that prey remains can pass through the food chain as the result of ...
List of Error-Prone Abbreviations, Symbols, and Dose Designations
... unit dose (e.g., diltiazem 125 mg IV infusion "UD" misin- Use "as directed" terpreted as meaning to give the entire infusion as a unit [bolus] dose) Misinterpretation Correction Mistaken ...
Propensity Score Weighting with Error-Prone Covariates
ERIC Educational Resources Information Center
McCaffrey, Daniel F.; Lockwood, J. R.; Setodji, Claude M.
Inverse probability weighting (IPW) estimates are widely used in applications where data are missing due to nonresponse or censoring or in observational studies of causal effects where the counterfactuals cannot be observed. This extensive literature has shown the estimators to be consistent and asymptotically normal under very general conditions,…
Replicative mechanisms for CNV formation are error prone
Technology Transfer Automated Retrieval System (TEKTRAN)
We investigated 67 breakpoint junctions of gene copy number gains in 31 unrelated subjects. We observed a strikingly high frequency of small deletions and insertions (29%) apparently originating from polymerase slippage events, in addition to frameshifts and point mutations in homonucleotide runs (1...
Development of a high-throughput real time PCR based on a hot-start alternative for Pfu mediated by quantum dots
NASA Astrophysics Data System (ADS)
Sang, Fuming; Yang, Yang; Yuan, Lin; Ren, Jicun; Zhang, Zhizhou
Hot start (HS) PCR is an excellent alternative for high-throughput real time PCR due to its ability to prevent nonspecific amplification at low temperature. Development of a cost-effective and simple HS PCR technique to guarantee high-throughput PCR specificity and consistency still remains a great challenge. In this study, we systematically investigated the HS characteristics of QDs triggered in real time PCR with EvaGreen and SYBR Green I dyes by the analysis of amplification curves, standard curves and melting curves. Two different kinds of DNA polymerases, Pfu and Taq, were employed. Here we showed that high specificity and efficiency of real time PCR were obtained in a plasmid DNA and an error-prone two-round PCR assay using QD-based HS PCR, even after an hour preincubation at 50 °C before real time PCR. Moreover, the results obtained by QD-based HS PCR were comparable to a commercial Taq antibody DNA polymerase. However, no obvious HS effect of QDs was found in real time PCR using Taq DNA polymerase. The findings of this study demonstrated that a cost-effective high-throughput real time PCR based on QD triggered HS PCR could be established with high consistency, sensitivity and accuracy.Hot start (HS) PCR is an excellent alternative for high-throughput real time PCR due to its ability to prevent nonspecific amplification at low temperature. Development of a cost-effective and simple HS PCR technique to guarantee high-throughput PCR specificity and consistency still remains a great challenge. In this study, we systematically investigated the HS characteristics of QDs triggered in real time PCR with EvaGreen and SYBR Green I dyes by the analysis of amplification curves, standard curves and melting curves. Two different kinds of DNA polymerases, Pfu and Taq, were employed. Here we showed that high specificity and efficiency of real time PCR were obtained in a plasmid DNA and an error-prone two-round PCR assay using QD-based HS PCR, even after an hour
Gardner, S N; Clague, D S; Vandersall, J A; Hon, G; Williams, P L
experiments were tainted by contaminated products received from the manufacturer. Much knowledge has been gained in the development of the code thus far, but without final debugging, increasing its robustness and verifying it against experimental results, the papers which we have drafted to share our findings still require the final data necessary for publication. The following sections summarize our final progress on VPCR as it stands after 1.5 years of effort on an ambitious project scoped for a 3 year period. We have additional details of the methods than are provided here, but would like to have legal protection in place before releasing them. The result of this project, a suite of programs that predict PCR products as a function of reaction conditions and sequences, will be used to address outstanding questions in pathogen detection and forensics at LLNL. VPCR should enable scientists to optimize PCR protocols in terms of time, temperature, ion concentration, and primer sequences and concentrations, and to estimate products and error rates in advance of performing experiments. Our proposed capabilities are well ahead of all currently available technologies, which do not model non-equilibrium kinetics, polymerase extension, or predict multiple or undesired PCR products. We are currently seeking DHS funding to complete the project, at which time licensing opportunities will be explored, an updated patent application will be prepared, and a publication will be submitted. A provisional and a full patent application have already been filed (1).
Vegetation fire proneness in Europe
NASA Astrophysics Data System (ADS)
Pereira, Mário; Aranha, José; Amraoui, Malik
Fire selectivity has been studied for vegetation classes in terms of fire frequency and fire size in a few European regions. This analysis is often performed along with other landscape variables such as topography, distance to roads and towns. These studies aims to assess the landscape sensitivity to forest fires in peri-urban areas and land cover changes, to define landscape management guidelines and policies based on the relationships between landscape and fires in the Mediterranean region. Therefore, the objectives of this study includes the: (i) analysis of the spatial and temporal variability statistics within Europe; and, (ii) the identification and characterization of the vegetated land cover classes affected by fires; and, (iii) to propose a fire proneness index. The datasets used in the present study comprises: Corine Land Cover (CLC) maps for 2000 and 2006 (CLC2000, CLC2006) and burned area (BA) perimeters, from 2000 to 2013 in Europe, provided by the European Forest Fire Information System (EFFIS). The CLC is a part of the European Commission programme to COoRdinate INformation on the Environment (Corine) and it provides consistent, reliable and comparable information on land cover across Europe. Both the CLC and EFFIS datasets were combined using geostatistics and Geographical Information System (GIS) techniques to access the spatial and temporal evolution of the types of shrubs and forest affected by fires. Obtained results confirms the usefulness and efficiency of the land cover classification scheme and fire proneness index which allows to quantify and to compare the propensity of vegetation classes and countries to fire. As expected, differences between northern and southern Europe are notorious in what concern to land cover distribution, fire incidence and fire proneness of vegetation cover classes. This work was supported by national funds by FCT - Portuguese Foundation for Science and Technology, under the project PEst-OE/AGR/UI4033/2014 and by
Prone and supine percutaneous nephrolithotomy.
Lucarelli, G; Breda, A
Since the first successful stone extraction through a nephrostomy in 1976, percutaneous nephrolithotomy (PCNL) has became the preferred procedure especially for treatment of large, complex and staghorn calculi. For decades this method has been performed with the patient in the prone position. More recently, particular interest has been taken on supine PCNL due to less anestesiological risks and the possibility of simultaneous anterograde and retrograde access to the whole urinary tract. Although many retrospective studies have been published, only two prospective trials comparing the two positions are reported in the literature. The best access to PCNL represents still a controversial issue. The overall experience reported in literature indicates that each modality is equally feasible and safe. Therefore, to date the surgeon's preference is the prime indication to one access over the other.
Prone positioning in acute respiratory distress syndrome.
Gibson, Kristy; Dufault, Marlene; Bergeron, Kathy
Acute respiratory distress syndrome (ARDS) is a condition with a high morbidity and mortality rate, and treatment is often long and costly. Prone positioning is a rarely used intervention for patients with this syndrome, although research suggests it may be effective. A literature search was undertaken to examine the effects of prone positioning on oxygenation, morbidity and mortality in patients with ARDS. It revealed that prone positioning, when used with low tidal volume ventilation over an extended period, may reduce mortality rates in selected patients with severe ARDS. The selection of patients with severe ARDS for prone positioning should be done on a case-by-case basis to maximise benefits and minimise complications. Further research is required on the use of prone positioning in patients with severe ARDS to support or disclaim the therapy's use in practice, and to compare confounding variables such as ideal prone duration and mechanical versus manual pronation.
Development of a high-throughput real time PCR based on a hot-start alternative for Pfu mediated by quantum dots.
Sang, Fuming; Yang, Yang; Yuan, Lin; Ren, Jicun; Zhang, Zhizhou
Hot start (HS) PCR is an excellent alternative for high-throughput real time PCR due to its ability to prevent nonspecific amplification at low temperature. Development of a cost-effective and simple HS PCR technique to guarantee high-throughput PCR specificity and consistency still remains a great challenge. In this study, we systematically investigated the HS characteristics of QDs triggered in real time PCR with EvaGreen and SYBR Green I dyes by the analysis of amplification curves, standard curves and melting curves. Two different kinds of DNA polymerases, Pfu and Taq, were employed. Here we showed that high specificity and efficiency of real time PCR were obtained in a plasmid DNA and an error-prone two-round PCR assay using QD-based HS PCR, even after an hour preincubation at 50 °C before real time PCR. Moreover, the results obtained by QD-based HS PCR were comparable to a commercial Taq antibody DNA polymerase. However, no obvious HS effect of QDs was found in real time PCR using Taq DNA polymerase. The findings of this study demonstrated that a cost-effective high-throughput real time PCR based on QD triggered HS PCR could be established with high consistency, sensitivity and accuracy.
Statistical approaches to account for false-positive errors in environmental DNA samples.
Lahoz-Monfort, José J; Guillera-Arroita, Gurutzeta; Tingley, Reid
Environmental DNA (eDNA) sampling is prone to both false-positive and false-negative errors. We review statistical methods to account for such errors in the analysis of eDNA data and use simulations to compare the performance of different modelling approaches. Our simulations illustrate that even low false-positive rates can produce biased estimates of occupancy and detectability. We further show that removing or classifying single PCR detections in an ad hoc manner under the suspicion that such records represent false positives, as sometimes advocated in the eDNA literature, also results in biased estimation of occupancy, detectability and false-positive rates. We advocate alternative approaches to account for false-positive errors that rely on prior information, or the collection of ancillary detection data at a subset of sites using a sampling method that is not prone to false-positive errors. We illustrate the advantages of these approaches over ad hoc classifications of detections and provide practical advice and code for fitting these models in maximum likelihood and Bayesian frameworks. Given the severe bias induced by false-negative and false-positive errors, the methods presented here should be more routinely adopted in eDNA studies.
Symmetric Biomechanically Guided Prone-to-Supine Breast Image Registration.
Eiben, Björn; Vavourakis, Vasileios; Hipwell, John H; Kabus, Sven; Buelow, Thomas; Lorenz, Cristian; Mertzanidou, Thomy; Reis, Sara; Williams, Norman R; Keshtgar, Mohammed; Hawkes, David J
Prone-to-supine breast image registration has potential application in the fields of surgical and radiotherapy planning, image guided interventions, and multi-modal cancer diagnosis, staging, and therapy response prediction. However, breast image registration of three dimensional images acquired in different patient positions is a challenging problem, due to large deformations induced to the soft breast tissue caused by the change in gravity loading. We present a symmetric, biomechanical simulation based registration framework which aligns the images in a central, virtually unloaded configuration. The breast tissue is modelled as a neo-Hookean material and gravity is considered as the main source of deformation in the original images. In addition to gravity, our framework successively applies image derived forces directly into the unloading simulation in place of a subsequent image registration step. This results in a biomechanically constrained deformation. Using a finite difference scheme avoids an explicit meshing step and enables simulations to be performed directly in the image space. The explicit time integration scheme allows the motion at the interface between chest and breast to be constrained along the chest wall. The feasibility and accuracy of the approach presented here was assessed by measuring the target registration error (TRE) using a numerical phantom with known ground truth deformations, nine clinical prone MRI and supine CT image pairs, one clinical prone-supine CT image pair and four prone-supine MRI image pairs. The registration reduced the mean TRE for the numerical phantom experiment from initially 19.3 to 0.9 mm and the combined mean TRE for all fourteen clinical data sets from 69.7 to 5.6 mm.
Men More Prone to Severe Psoriasis
... fullstory_164498.html Men More Prone to Severe Psoriasis: Study Researchers say this may explain why more ... 2017 THURSDAY, April 6, 2017 (HealthDay News) -- Severe psoriasis is much more common in men than women, ...
Smokers Prone to Problems After Joint Replacement
... fullstory_164137.html Smokers Prone to Problems After Joint Replacement: Study Cessation programs help reduce the rate ... that smokers do worse than non-smokers after joint replacements, and now this research shows there's good ...
Ethnic and gender differences in boredom proneness
Gibson, G.S.; Morales,
Although boredom may exhibit many shared elements, culturally specific attitudes have also been found to exist. The present paper investigated boredom proneness among African-American college students. Data from 120 participants on the Boredom Proneness (BP) Scale was analyzed and compared to cross-cultural participants. African-American females scored significantly higher than African-American males. Scores were presented from two other studies to show a comparative look at boredom proneness in five other ethnic groups. African-American females are the only female ethnic group to score higher on the BP Scale than their male counterparts. Additionally, overall African-Americans, were found to have higher BP scores than their Western counterparts.
Isometric elbow extensors strength in supine- and prone-lying positions.
Abdelzaher, Ibrahim E; Ababneh, Anas F; Alzyoud, Jehad M
The purpose of this study was to compare isometric strength of elbow extensors measured in supine- and prone-lying positions at elbow flexion angles of 45 and 90 degrees. Twenty-two male subjects under single-blind procedures participated in the study. Each subject participated in both supine-lying and prone-lying measuring protocols. Calibrated cable tensiometer was used to measure isometric strength of the right elbow extensors and a biofeedback electromyography was used to assure no substitution movements from shoulder girdle muscles. The mean values of isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees were 11.1 ± 4.2 kg and 13.1 ± 4.6 kg, while those measured from prone-lying position were 9.9 ± 3.6 kg and 12 ± 4.2 kg, respectively. There is statistical significant difference between the isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees compared to that measured from prone-lying position (p < 0.05). The results suggest that in manual muscle testing starting position can affect the isometric strength of elbow extensors since supine-lying starting position is better than prone-lying starting position.
A computerized methodology for improved virus typing by PCR-RFLP gel electrophoresis.
Maramis, Christos F; Delopoulos, Anastasios N; Lambropoulos, Alexandros F
The analysis of digitized images from polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP)gel electrophoresis examinations is a popular method for virus typing, i.e., for identifying the virus type(s) that have infected an investigated biological sample. However, being mostly manual, the conventional virus typing protocol remains laborious, time consuming, and error prone. In order to overcome these shortcomings,we propose a computerized methodology for improving virus typing via PCR-RFLP gel electrophoresis. A novel realistic observation model of the viral DNA motion on the gel matrix is employed to assist in exploiting additional virus-related information in comparison to the conventional approaches. The extracted rich information is fed to a novel typing algorithm, resulting in faster and more accurate decisions. The proposed methodology is evaluated for the case of the human papillomavirus typing on a dataset of 80 real and 1500 simulated samples, producing very satisfactory results.Ind
Alternated Prone and Supine Whole-Breast Irradiation Using IMRT: Setup Precision, Respiratory Movement and Treatment Time
Veldeman, Liv; De Gersem, Werner; Speleers, Bruno; Truyens, Bart; Van Greveling, Annick; Van den Broecke, Rudy; De Neve, Wilfried
Purpose: The objective of this study was to compare setup precision, respiration-related breast movement and treatment time between prone and supine positions for whole-breast irradiation. Methods and Materials: Ten patients with early-stage breast carcinoma after breast-conserving surgery were treated with prone and supine whole breast-irradiation in a daily alternating schedule. Setup precision was monitored using cone-beam computed tomography (CBCT) imaging. Respiration-related breast movement in the vertical direction was assessed by magnetic sensors. The time needed for patient setup and for the CBCT procedure, the beam time, and the length of the whole treatment slot were also recorded. Results: Random and systematic errors were not significantly different between positions in individual patients for each of the three axes (left-right, longitudinal, and vertical). Respiration-related movement was smaller in prone position, but about 80% of observations showed amplitudes <1 mm in both positions. Treatment slots were longer in prone position (21.2 {+-} 2.5 min) than in supine position (19.4 {+-} 0.8 min; p = 0.044). Conclusion: Comparison of setup precision between prone and supine position in the same patient showed no significant differences in random and systematic errors. Respiratory movement was smaller in prone position. The longer treatment slots in prone position can probably be attributed to the higher repositioning need.
Reasoning, delusion proneness and stress: an experimental investigation.
Keefe, Kristy M; Warman, Debbie M
Previous studies have been inconsistent in demonstrating a relationship between delusion proneness and induced stress on reasoning biases. The present study was an experimental investigation of the role of stress in the form of feeling rushed, which has previously been shown to be related to the jumping-to-conclusions reasoning bias for delusion-prone individuals, on the reasoning of delusion-prone individuals. University students (n = 133) completed a measure of delusion proneness and were randomly assigned to either receive or not receive a stress induction in the form of a speeded subtraction task. All participants engaged in four trials of a probabilistic reasoning task. Delusion-prone and not delusion-prone participants performed similarly when there was no stress induction, but delusion-prone individuals demonstrated reasoning biases relative to not delusion-prone individuals when stress was induced. The reasoning of delusion-prone individuals may be particularly vulnerable when they feel rushed and in stressful conditions.
Covariation bias in panic-prone individuals.
Pauli, P; Montoya, P; Martz, G E
Covariation estimates between fear-relevant (FR; emergency situations) or fear-irrelevant (FI; mushrooms and nudes) stimuli and an aversive outcome (electrical shock) were examined in 10 high-fear (panic-prone) and 10 low-fear respondents. When the relation between slide category and outcome was random (illusory correlation), only high-fear participants markedly overestimated the contingency between FR slides and shocks. However, when there was a high contingency of shocks following FR stimuli (83%) and a low contingency of shocks following FI stimuli (17%), the group difference vanished. Reversal of contingencies back to random induced a covariation bias for FR slides in high- and low-fear respondents. Results indicate that panic-prone respondents show a covariation bias for FR stimuli and that the experience of a high contingency between FR slides and aversive outcomes may foster such a covariation bias even in low-fear respondents.
Increase in error threshold for quasispecies by heterogeneous replication accuracy
NASA Astrophysics Data System (ADS)
Aoki, Kazuhiro; Furusawa, Mitsuru
In this paper we investigate the error threshold for quasispecies with heterogeneous replication accuracy. We show that the coexistence of error-free and error-prone polymerases can greatly increase the error threshold without a catastrophic loss of genetic information. We also show that the error threshold is influenced by the number of replicores. Our research suggests that quasispecies with heterogeneous replication accuracy can reduce the genetic cost of selective evolution while still producing a variety of mutants.
Paranormal belief and proneness to dissociation.
Irwin, H J
The study investigated the relationship between scores on paranormal belief and proneness to dissociation in a sample of 100 Australian students of psychology. Scores on dissociation were positively correlated with those on global paranormal belief and with belief in psi, precognition, spiritualism, and extraordinary life-forms. It is suggested that in some instances paranormal beliefs may be a component of a complex defensive framework constructed in the face of the perceived uncontrollability of life.
Genetic Screen for PTSD-Prone Soldiers
for determining genotypes at 8 loci in the calcyon gene which is strongly associated with attention deficit hyperactivity disorder (ADHD) and...associated with attention deficit hyperactivity disorder (ADHD) could be useful as an unbiased screen for PTSD-prone soldiers. Subjects participating... deficit / hyperactivity disorder . Mol. Psychiatry 10, 1117-1125. Li,J.Z., Absher,D.M., Tang,H., Southwick,A.M., Casto,A.M., Ramachandran,S., Cann,H.M
Registration of prone and supine CT colonography scans using correlation optimized warping and canonical correlation analysis
Wang Shijun; Yao Jianhua; Liu Jiamin; Petrick, Nicholas; Van Uitert, Robert L.; Periaswamy, Senthil; Summers, Ronald M.
Purpose: In computed tomographic colonography (CTC), a patient will be scanned twice--Once supine and once prone--to improve the sensitivity for polyp detection. To assist radiologists in CTC reading, in this paper we propose an automated method for colon registration from supine and prone CTC scans. Methods: We propose a new colon centerline registration method for prone and supine CTC scans using correlation optimized warping (COW) and canonical correlation analysis (CCA) based on the anatomical structure of the colon. Four anatomical salient points on the colon are first automatically distinguished. Then correlation optimized warping is applied to the segments defined by the anatomical landmarks to improve the global registration based on local correlation of segments. The COW method was modified by embedding canonical correlation analysis to allow multiple features along the colon centerline to be used in our implementation. Results: We tested the COW algorithm on a CTC data set of 39 patients with 39 polyps (19 training and 20 test cases) to verify the effectiveness of the proposed COW registration method. Experimental results on the test set show that the COW method significantly reduces the average estimation error in a polyp location between supine and prone scans by 67.6%, from 46.27{+-}52.97 to 14.98 mm{+-}11.41 mm, compared to the normalized distance along the colon centerline algorithm (p<0.01). Conclusions: The proposed COW algorithm is more accurate for the colon centerline registration compared to the normalized distance along the colon centerline method and the dynamic time warping method. Comparison results showed that the feature combination of z-coordinate and curvature achieved lowest registration error compared to the other feature combinations used by COW. The proposed method is tolerant to centerline errors because anatomical landmarks help prevent the propagation of errors across the entire colon centerline.
[Ketosis prone type 2 diabetes (KPD)].
Concha L, Luciana; Durruty A, Pilar; García de Los Ríos A, Manuel
Ketosis prone type 2 diabetes (KPD) is presently a well-defined clinical entity, characterized by a debut with severe hyperglycemia and ketoacidosis similar to the presenting form of Type 1 diabetes mellitus (DM1). However, it appears in subjects with Type 2 diabetes mellitus (DM2) phenotype. This situation is caused by an acute, reversible dysfunction of the beta cell in individuals with insulin resistance. Once the acute stage subsides, patients behave as having a DM2 and do not require insulin treatment. They should be kept on a diet and oral hypoglycemic drugs due to their susceptibility to have recurrent acute ketotic decompensations.
Extralevator abdominoperineal resection in the prone position.
Flor-Lorente, Blas; Frasson, Matteo; Montilla, Erick
The Miles operation is every day more in the limelight. The abdominoperineal resection compared to anterior resection results in increased rate of circumferential resection margin (CRM) infiltration, increased iatrogenic tumor perforation rate and poorer quality of the mesorectum. These worse results may be caused by excessive dissection between the distal mesorectum and the plane of the levator ani and the consequent "resection waist" or "cone" effect in the specimen. A wider excision of the pelvic floor muscles, known as extraelevator abdominoperineal resection (ELAPE), would provide a "cylindrical" specimen which would hypothetically reduce the risk of tumor perforation and CRM infiltration and local recurrence rate. However, there is insufficient evidence to conclude that the ELAPE is oncologically superior compared to standard abdominoperineal resection. Independently from the surgical technique adopted, another actual point of discussion is the position of the patient during the perineal part of the operation. The position on "prone" provides excellent pelvic exposure, a top-down dissection under direct vision and is very comfortable for the operating surgeons. However, there is no clear scientific evidence of the superiority of prone ELAPE over supine ELAPE in terms of oncologic results, morbidity and mortality. The laparoscopy seems to be the best surgical approach for the abdominal part of the operation, although it has not been validated so far by large prospective studies. Prospective, controlled and randomized trials are necessary to resolve all these issues. The current interest in a more accurate and standardized perineal surgery to obtain a cylindrical specimen, undoubtedly, will improve results.
Does logic moderate the fundamental attribution error?
Stalder, D R
The fundamental attribution error was investigated from an individual difference perspective. Mathematicians were compared with nonmathematicians (Exp. 1; n: 84), and undergraduates who scored high on a test of logical reasoning ability were compared with those who scored low (Exp. 2; n: 62). The mathematicians and those participants scoring higher on logic appeared less prone to the fundamental attribution error, primarily using a measure of confidence in attributions.
The Impact of Covariate Measurement Error on Risk Prediction
Khudyakov, Polyna; Gorfine, Malka; Zucker, David; Spiegelman, Donna
In the development of risk prediction models, predictors are often measured with error. In this paper, we investigate the impact of covariate measurement error on risk prediction. We compare the prediction performance using a costly variable measured without error, along with error-free covariates, to that of a model based on an inexpensive surrogate along with the error-free covariates. We consider continuous error-prone covariates with homoscedastic and heteroscedastic errors, and also a discrete misclassified covariate. Prediction performance is evaluated by the area under the receiver operating characteristic curve (AUC), the Brier score (BS), and the ratio of the observed to the expected number of events (calibration). In an extensive numerical study, we show that (i) the prediction model with the error-prone covariate is very well calibrated, even when it is mis-specified; (ii) using the error-prone covariate instead of the true covariate can reduce the AUC and increase the BS dramatically; (iii) adding an auxiliary variable, which is correlated with the error-prone covariate but conditionally independent of the outcome given all covariates in the true model, can improve the AUC and BS substantially. We conclude that reducing measurement error in covariates will improve the ensuing risk prediction, unless the association between the error-free and error-prone covariates is very high. Finally, we demonstrate how a validation study can be used to assess the effect of mismeasured covariates on risk prediction. These concepts are illustrated in a breast cancer risk prediction model developed in the Nurses' Health Study. PMID:25865315
... common links HHS U.S. Department of Health and Human Services U.S. Food and Drug Administration A to Z Index Follow ... Practices National Patient Safety Foundation To Err is Human: ... Errors: Quality Chasm Series National Coordinating Council for Medication Error ...
NASA Astrophysics Data System (ADS)
Scherer, Philipp O. J.
Input data as well as the results of elementary operations have to be represented by machine numbers, the subset of real numbers which is used by the arithmetic unit of today's computers. Generally this generates rounding errors. This kind of numerical error can be avoided in principle by using arbitrary precision arithmetics or symbolic algebra programs. But this is unpractical in many cases due to the increase in computing time and memory requirements. Results from more complex operations like square roots or trigonometric functions can have even larger errors since series expansions have to be truncated and iterations accumulate the errors of the individual steps. In addition, the precision of input data from an experiment is limited. In this chapter we study the influence of numerical errors on the uncertainties of the calculated results and the stability of simple algorithms.
Benett, William J.; Richards, James B.
A sleeve-type silicon polymerase chain reaction (PCR) chamber or thermocycler having improved thermal performance. The silicon sleeve reaction chamber is improved in thermal performance by etched features therein that reduce thermal mass and increase the surface area of the sleeve for cooling. This improved thermal performance of the thermocycler enables an increase in speed and efficiency of the reaction chamber. The improvement is accomplished by providing grooves in the faces of the sleeve and a series of grooves on the interior surfaces that connect with grooves on the faces of the sleeve. The grooves can be anisotropically etched in the silicon sleeve simultaneously with formation of the chamber.
Benett, William J.; Richards, James B.
A sleeve-type silicon polymerase chain reaction (PCR) chamber or thermocycler having improved thermal performance. The silicon sleeve reaction chamber is improved in thermal performance by etched features therein that reduce thermal mass and increase the surface area of the sleeve for cooling. This improved thermal performance of the thermocycler enables an increase in speed and efficiency of the reaction chamber. The improvement is accomplished by providing grooves in the faces of the sleeve and a series of grooves on the interior surfaces that connect with grooves on the faces of the sleeve. The grooves can be anisotropically etched in the silicon sleeve simultaneously with formation of the chamber.
Neglected Children, Shame-Proneness, and Depressive Symptoms
Bennett, David S.; Sullivan, Margaret Wolan; Lewis, Michael
Neglected children may be at increased risk for depressive symptoms. This study examines shame-proneness as an outcome of child neglect and as a potential explanatory variable in the relation between neglect and depressive symptoms. Participants were 111 children (52 with a Child Protective Services [CPS] allegation of neglect) seen at age 7. Neglected children reported more shame-proneness and more depressive symptoms than comparison children. Guilt-proneness, in contrast, was unrelated to neglect and depressive symptoms, indicating specificity for shame-proneness. The potential role of shame as a process variable that can help explain how some neglected children exhibit depressive symptoms is discussed. PMID:20724372
Piezoelectric control of structures prone to instabilities
NASA Astrophysics Data System (ADS)
Kim, Sunjung
Thin-walled structures such as stiffened panels fabricated out of high strength materials are ubiquitous in aerospace structures. These are prone to buckle in a variety of modes with strong possibility of adverse interaction under axial compression and/or bending. Optimally designed stiffened panels, at an appropriate combination of axial compression and suddenly applied lateral pressure undergo large amplitude oscillations and may experience divergence. Under aerodynamic loading, they can experience flutter instability with the amplitudes of oscillations attaining a limit (LCO) or escalating without any limit. Control of structures prone to these forms of instability using piezo-electric actuators is the theme of this dissertation. Issues involved in the control of stiffened panels under axial compression and liable to buckle simultaneously in local and overall modes are studied. The analytical approach employs finite elements in which are embedded periodic components of local buckling including the second order effects. It is shown that the adverse effects of mode interaction can be counteracted by simply controlling the overall bending of the stiffener by piezo-electric actuators attached its tips. Control is exercised by self-sensing actuators by direct negative feedback voltages proportional to the bending strains of the stiffener. In a dynamic loading environment, where vibrations are triggered by suddenly applied lateral pressure, negative velocity feedback is employed with voltages proportional to the bending strain-rate. The local plate oscillations are effectively controlled by a piezo-electric actuators placed along the longitudinal center line of the panel. The problem of flutter under aerodynamic pressure of stiffened panels in the linear and post-critical regimes is studied using modal analysis and finite strips. The analysis, control and interpretation of the response are facilitated by identification of two families of characteristic modes of
Error Detection and Error Classification: Failure Awareness in Data Transfer Scheduling
Louisiana State University; Balman, Mehmet; Kosar, Tevfik
Data transfer in distributed environment is prone to frequent failures resulting from back-end system level problems, like connectivity failure which is technically untraceable by users. Error messages are not logged efficiently, and sometimes are not relevant/useful from users point-of-view. Our study explores the possibility of an efficient error detection and reporting system for such environments. Prior knowledge about the environment and awareness of the actual reason behind a failure would enable higher level planners to make better and accurate decisions. It is necessary to have well defined error detection and error reporting methods to increase the usability and serviceability of existing data transfer protocols and data management systems. We investigate the applicability of early error detection and error classification techniques and propose an error reporting framework and a failure-aware data transfer life cycle to improve arrangement of data transfer operations and to enhance decision making of data transfer schedulers.
Empirical evaluation of humpback whale telomere length estimates; quality control and factors causing variability in the singleplex and multiplex qPCR methods
Background Telomeres, the protective cap of chromosomes, have emerged as powerful markers of biological age and life history in model and non-model species. The qPCR method for telomere length estimation is one of the most common methods for telomere length estimation, but has received recent critique for being too error-prone and yielding unreliable results. This critique coincides with an increasing awareness of the potentials and limitations of the qPCR technique in general and the proposal of a general set of guidelines (MIQE) for standardization of experimental, analytical, and reporting steps of qPCR. In order to evaluate the utility of the qPCR method for telomere length estimation in non-model species, we carried out four different qPCR assays directed at humpback whale telomeres, and subsequently performed a rigorous quality control to evaluate the performance of each assay. Results Performance differed substantially among assays and only one assay was found useful for telomere length estimation in humpback whales. The most notable factors causing these inter-assay differences were primer design and choice of using singleplex or multiplex assays. Inferred amplification efficiencies differed by up to 40% depending on assay and quantification method, however this variation only affected telomere length estimates in the worst performing assays. Conclusion Our results suggest that seemingly well performing qPCR assays may contain biases that will only be detected by extensive quality control. Moreover, we show that the qPCR method for telomere length estimation can be highly precise and accurate, and thus suitable for telomere measurement in non-model species, if effort is devoted to optimization at all experimental and analytical steps. We conclude by highlighting a set of quality controls which may serve for further standardization of the qPCR method for telomere length estimation, and discuss some of the factors that may cause variation in qPCR experiments
Rude, Disrespectful Surgeons May Also Be More Error-Prone: Study
... also more likely to make mistakes in the operating room, a new study finds. Researchers compared surgical outcomes with patient reports of unprofessional behavior by their doctors at several health systems in the United States. The investigators found that ...
Error-prone initiation factor 2 mutations reduce the fitness cost of antibiotic resistance
Zorzet, Anna; Pavlov, Michael Y; Nilsson, Annika I; Ehrenberg, Måns; Andersson, Dan I
Mutations in the fmt gene (encoding formyl methionine transferase) that eliminate formylation of initiator tRNA (Met-tRNAi) confer resistance to the novel antibiotic class of peptide deformylase inhibitors (PDFIs) while concomitantly reducing bacterial fitness. Here we show in Salmonella typhimurium that novel mutations in initiation factor 2 (IF2) located outside the initiator tRNA binding domain can partly restore fitness of fmt mutants without loss of antibiotic resistance. Analysis of initiation of protein synthesis in vitro showed that with non-formylated Met-tRNAi IF2 mutants initiated much faster than wild-type IF2, whereas with formylated fMet-tRNAi the initiation rates were similar. Moreover, the increase in initiation rates with Met-tRNAi conferred by IF2 mutations in vitro correlated well with the increase in growth rate conferred by the same mutations in vivo, suggesting that the mutations in IF2 compensate formylation deficiency by increasing the rate of in vivo initiation with Met-tRNAi. IF2 mutants had also a high propensity for erroneous initiation with elongator tRNAs in vitro, which could account for their reduced fitness in vivo in a formylation-proficient strain. More generally, our results suggest that bacterial protein synthesis is mRNA-limited and that compensatory mutations in IF2 could increase the persistence of PDFI-resistant bacteria in clinical settings. PMID:20132454
Psychological performance of accident-prone automobile drivers in China: a case-control study.
Jin, H Q; Araki, S; Wu, X K; Zhang, Y W; Yokoyama, K
To evaluate the role of neurobehavioural factors in the aetiology of recurrent automobile accidents, we administered the Revised Wechsler Adult Intelligence Scale (WAIS-R), the Eysenck Personality Questionnaire (EPQ), and choice and simple reaction time tests to 31 accident-prone automobile drivers. These drivers who had caused three or more traffic accidents during the years 1980-1984, were selected from records of 2723 traffic accidents registered by Hefei Traffic Police Department during the years 1980-1984. The same tests were administered to an equal number of sex- and age-matched control drivers who had no reported involvement in automobile accidents. None of the subjects had suffered from any neuropsychiatric illness or head injury. Comparisons between the two groups indicated that for accident-prone drivers scores on picture completion and block design subtests of the WAIS-R were significantly lowered (p less than 0.05); scores for neurosis extrovert behaviour and psychosis (EPQ) were significantly higher (p less than 0.05); and the number of errors in the choice reaction time test was significantly higher (p less than 0.01). It is suggested that accident-prone drivers have lower psychological performance, poorer judgement and a higher tendency than safe drivers to be neurotic, extrovert and psychotic.
Comparison of Droplet Digital PCR and qPCR for the Quantification of Shiga Toxin-Producing Escherichia coli in Bovine Feces.
Verhaegen, Bavo; De Reu, Koen; De Zutter, Lieven; Verstraete, Karen; Heyndrickx, Marc; Van Coillie, Els
Cattle are considered to be the main reservoir for Shiga toxin-producing Escherichia coli (STEC) and are often the direct or indirect source of STEC outbreaks in humans. Accurate measurement of the concentration of shed STEC in cattle feces could be a key answer to questions concerning transmission of STEC, contamination sources and efficiency of treatments at farm level. Infected animals can be identified and the contamination level quantified by real-time quantitative PCR (qPCR), which has its specific limitations. Droplet digital PCR (ddPCR) has been proposed as a method to overcome many of the drawbacks of qPCR. This end-point amplification PCR is capable of absolute quantification independent from any reference material and is less prone to PCR inhibition than qPCR. In this study, the qPCR-based protocol described by Verstraete et al. (2014) for Shiga toxin genes stx1 and stx2 and the intimin gene eae quantification was optimized for ddPCR analysis. The properties of ddPCR and qPCR using two different mastermixes (EMM: TaqMan(®) Environmental Master Mix 2.0; UMM: TaqMan(®) Universal PCR Master Mix) were evaluated, using standard curves and both artificial and natural contaminated cattle fecal samples. In addition, the susceptibility of these assays to PCR-inhibitors was investigated. Evaluation of the standard curves and both artificial and natural contaminated cattle fecal samples suggested a very good agreement between qPCR using EMM and ddPCR. Furthermore, similar sensitivities and no PCR inhibition were recorded for both assays. On the other hand, qPCR using UMM was clearly prone to PCR inhibition. In conclusion, the ddPCR technique shows potential for the accurate absolute quantification of STEC on the farms, without relying on standardized reference material.
Comparison of Droplet Digital PCR and qPCR for the Quantification of Shiga Toxin-Producing Escherichia coli in Bovine Feces
Verhaegen, Bavo; De Reu, Koen; De Zutter, Lieven; Verstraete, Karen; Heyndrickx, Marc; Van Coillie, Els
Cattle are considered to be the main reservoir for Shiga toxin-producing Escherichia coli (STEC) and are often the direct or indirect source of STEC outbreaks in humans. Accurate measurement of the concentration of shed STEC in cattle feces could be a key answer to questions concerning transmission of STEC, contamination sources and efficiency of treatments at farm level. Infected animals can be identified and the contamination level quantified by real-time quantitative PCR (qPCR), which has its specific limitations. Droplet digital PCR (ddPCR) has been proposed as a method to overcome many of the drawbacks of qPCR. This end-point amplification PCR is capable of absolute quantification independent from any reference material and is less prone to PCR inhibition than qPCR. In this study, the qPCR-based protocol described by Verstraete et al. (2014) for Shiga toxin genes stx1 and stx2 and the intimin gene eae quantification was optimized for ddPCR analysis. The properties of ddPCR and qPCR using two different mastermixes (EMM: TaqMan® Environmental Master Mix 2.0; UMM: TaqMan® Universal PCR Master Mix) were evaluated, using standard curves and both artificial and natural contaminated cattle fecal samples. In addition, the susceptibility of these assays to PCR-inhibitors was investigated. Evaluation of the standard curves and both artificial and natural contaminated cattle fecal samples suggested a very good agreement between qPCR using EMM and ddPCR. Furthermore, similar sensitivities and no PCR inhibition were recorded for both assays. On the other hand, qPCR using UMM was clearly prone to PCR inhibition. In conclusion, the ddPCR technique shows potential for the accurate absolute quantification of STEC on the farms, without relying on standardized reference material. PMID:27213452
Dissociation and fantasy proneness in psychiatric patients: a preliminary study.
Merckelbach, Harald; à Campo, Joost; Hardy, Solange; Giesbrecht, Timo
Nonclinical studies found that dissociative experiences are intimately linked to a trait known as fantasy proneness. We examined the links among dissociative symptoms, fantasy proneness, and impulsivity in psychiatric outpatients. Our sample consisted of 22 patients with schizophrenia, 20 patients with a diagnosis of borderline personality disorder, and 19 patients with a major depressive disorder. For the whole sample, levels of dissociation were found to be related to fantasy proneness and impulsivity. There were group differences in dissociative symptoms, with patients with borderline personality disorder reporting more such symptoms than patients with either schizophrenia or major depressive disorder. The overlap between dissociation and fantasy proneness may have important ramifications for studies addressing comorbid phenomena of dissociative symptoms.
Empathy, Guilt Proneness, and Gender: Relative Contributions to Prosocial Behaviour
Torstveit, Linda; Sütterlin, Stefan; Lugo, Ricardo Gregorio
Guilt is a moral emotion that is often looked upon as a negative trait. However, studies show that some individuals are more predisposed to think, feel and act in a more ethical manner because of a lower threshold to experience guilt. Some theories of helping behaviour emphasize the evolutionary mechanisms, while other theories stress the importance of social variables. This study investigated whether guilt proneness as a dispositional trait can be associated with prosocial behaviour. Five hundred sixty-nine participants reported in an online survey their own levels of guilt proneness, frequency of prosocial behaviour, and related cognitions such as empathy. This study is among the first to demonstrate how guilt proneness combined with empathy can explain additional variance in prosocial behaviour. The findings also indicate gender differences in the precursors of prosocial behaviour, suggesting women are more influenced by the effects of guilt proneness on prosocial behaviour than men. PMID:27298635
Empathy, Guilt Proneness, and Gender: Relative Contributions to Prosocial Behaviour.
Torstveit, Linda; Sütterlin, Stefan; Lugo, Ricardo Gregorio
Guilt is a moral emotion that is often looked upon as a negative trait. However, studies show that some individuals are more predisposed to think, feel and act in a more ethical manner because of a lower threshold to experience guilt. Some theories of helping behaviour emphasize the evolutionary mechanisms, while other theories stress the importance of social variables. This study investigated whether guilt proneness as a dispositional trait can be associated with prosocial behaviour. Five hundred sixty-nine participants reported in an online survey their own levels of guilt proneness, frequency of prosocial behaviour, and related cognitions such as empathy. This study is among the first to demonstrate how guilt proneness combined with empathy can explain additional variance in prosocial behaviour. The findings also indicate gender differences in the precursors of prosocial behaviour, suggesting women are more influenced by the effects of guilt proneness on prosocial behaviour than men.
The Role of a Prone Setup in Breast Radiation Therapy
Huppert, Nelly; Jozsef, Gabor; DeWyngaert, Keith; Formenti, Silvia Chiara
Most patients undergoing breast conservation therapy receive radiotherapy in the supine position. Historically, prone breast irradiation has been advocated for women with large pendulous breasts in order to decrease acute and late toxicities. With the advent of CT planning, the prone technique has become both feasible and reproducible. It was shown to be advantageous not only for women with larger breasts but in most patients since it consistently reduces, if not eliminates, the inclusion of heart and lung within the field. The prone setup has been accepted as the best localizing position for both MRI and stereotactic biopsy, but its adoption has been delayed in radiotherapy. New technological advances including image-modulated radiation therapy and image-guided radiation therapy have made possible the exploration of accelerated fractionation schemes with a concomitant boost to the tumor bed in the prone position, along with better imaging and verification of reproducibility of patient setup. This review describes some of the available techniques for prone breast radiotherapy and the available experience in their application. The NYU prone breast radiotherapy approach is discussed, including a summary of the results from several prospective trials. PMID:22655240
The role of a prone setup in breast radiation therapy.
Huppert, Nelly; Jozsef, Gabor; Dewyngaert, Keith; Formenti, Silvia Chiara
Most patients undergoing breast conservation therapy receive radiotherapy in the supine position. Historically, prone breast irradiation has been advocated for women with large pendulous breasts in order to decrease acute and late toxicities. With the advent of CT planning, the prone technique has become both feasible and reproducible. It was shown to be advantageous not only for women with larger breasts but in most patients since it consistently reduces, if not eliminates, the inclusion of heart and lung within the field. The prone setup has been accepted as the best localizing position for both MRI and stereotactic biopsy, but its adoption has been delayed in radiotherapy. New technological advances including image-modulated radiation therapy and image-guided radiation therapy have made possible the exploration of accelerated fractionation schemes with a concomitant boost to the tumor bed in the prone position, along with better imaging and verification of reproducibility of patient setup. This review describes some of the available techniques for prone breast radiotherapy and the available experience in their application. The NYU prone breast radiotherapy approach is discussed, including a summary of the results from several prospective trials.
Understanding and Confronting Our Mistakes: The Epidemiology of Error in Radiology and Strategies for Error Reduction.
Bruno, Michael A; Walker, Eric A; Abujudeh, Hani H
Arriving at a medical diagnosis is a highly complex process that is extremely error prone. Missed or delayed diagnoses often lead to patient harm and missed opportunities for treatment. Since medical imaging is a major contributor to the overall diagnostic process, it is also a major potential source of diagnostic error. Although some diagnoses may be missed because of the technical or physical limitations of the imaging modality, including image resolution, intrinsic or extrinsic contrast, and signal-to-noise ratio, most missed radiologic diagnoses are attributable to image interpretation errors by radiologists. Radiologic interpretation cannot be mechanized or automated; it is a human enterprise based on complex psychophysiologic and cognitive processes and is itself subject to a wide variety of error types, including perceptual errors (those in which an important abnormality is simply not seen on the images) and cognitive errors (those in which the abnormality is visually detected but the meaning or importance of the finding is not correctly understood or appreciated). The overall prevalence of radiologists' errors in practice does not appear to have changed since it was first estimated in the 1960s. The authors review the epidemiology of errors in diagnostic radiology, including a recently proposed taxonomy of radiologists' errors, as well as research findings, in an attempt to elucidate possible underlying causes of these errors. The authors also propose strategies for error reduction in radiology. On the basis of current understanding, specific suggestions are offered as to how radiologists can improve their performance in practice.
DEM-based Approaches for the Identification of Flood Prone Areas
NASA Astrophysics Data System (ADS)
Samela, Caterina; Manfreda, Salvatore; Nardi, Fernando; Grimaldi, Salvatore; Roth, Giorgio; Sole, Aurelia
Manfreda et al. (2011) that suggested a modified Topographic Index (TIm) for the identification of flood prone area. 4) The downslope index proposed by Hjerdt et al. (2004) that quantifies the topographic controls on hydrology by evaluating head differences following the (surface) flow path in the steepest direction. The method does not use the exit point at the stream as reference; instead, the algorithm looks at how far a parcel of water has to travel along its flow path to lose a given head potential, d [m]. This last index was not defined with the aim to describe flood prone areas; in fact it represents an interesting alternative descriptor of morphological features that deserve to be tested. Analyses have been carried out for some Italian catchments. The outcomes of the four methods are presented using, for calibration and validation purposes, flood inundation maps made available by River Basin Authorities. The aim is, therefore, to evaluate the reliability and the relative errors in the detection of the areas subject to the flooding hazard. These techniques should not be considered as an alternative of traditional procedures, but additional tool for the identification of flood-prone areas and hazard graduation over large regions or when a preliminary identification is needed. Reference Degiorgis M., G. Gnecco, S. Gorni, G. Roth, M. Sanguineti, A. C. Taramasso, Classifiers for the detection of flood-prone areas using remote sensed elevation data, J. Hydrol., 470-471, 302-315, 2012. Hjerdt, K. N., J. J. McDonnell, J. Seibert, A. Rodhe, A new topographic index to quantify downslope controls on local drainage, Water Resour. Res., 40, W05602, 2004. Manfreda, S., M. Di Leo, A. Sole, Detection of Flood Prone Areas using Digital Elevation Models, Journal of Hydrologic Engineering, Vol. 16, No. 10, 781-790, 2011. Nardi, F., E. R. Vivoni, S. Grimaldi, Investigating a floodplain scaling relation using a hydrogeomorphic delineation method, Water Resour. Res., 42, W09409, 2006.
ERIC Educational Resources Information Center
Kima, Peter E.; Rasche, Madeline E.
PCR has revolutionized many aspects of biochemistry and molecular biology research. In the following exercise, students learn PCR by isolating their own DNA, amplifying specific segments of the X and Y chromosomes, and estimating the sizes of the PCR products using agarose gel electrophoresis. Based on the pattern of PCR products, students can…
The relationship between fantasy proneness and schizotypy in adolescents.
Sánchez-Bernardos, María Luisa; Avia, María Dolores
Previous research has found substantial relationships between fantasy proneness and schizotypy in adulthood. The aim of the present study is to examine the connections between these constructs in an adolescent sample. A sample of 511 adolescents filled out a measure of fantasy proneness and a measure of psychotic-like phenomena. The factorial pattern for schizotypal traits in adolescents replicate the earlier documented three-factor structure. Also, the full range of schizotypal features was found to be related to imaginative tendencies tapped by fantasy proneness. Finally, joint analysis of fantasy and schizotypy showed that, in adolescents, fantasy converges with magical ideation and the cognitive-perceptual dimension of schizotypy, but diverges from the interpersonal aspects of schizotypy.
Right-frontal cortical asymmetry predicts increased proneness to nostalgia.
Tullett, Alexa M; Wildschut, Tim; Sedikides, Constantine; Inzlicht, Michael
Nostalgia is often triggered by feelings-such as sadness, loneliness, or meaninglessness-that are typically associated with withdrawal motivation. Here, we examined whether a trait tendency to experience withdrawal motivation is associated with nostalgia proneness. Past work indicates that baseline right-frontal cortical asymmetry is a neural correlate of withdrawal-related motivation. We therefore hypothesized that higher baseline levels of right-frontal asymmetry would predict increased proneness to nostalgia. We assessed participants' baseline levels of frontal cortical activity using EEG. Results supported the hypothesis and demonstrated that the association between relative right-frontal asymmetry and increased nostalgia remained significant when controlling for the Big Five personality traits. Overall, these findings indicate that individuals with a stronger dispositional tendency to experience withdrawal-related motivation are more prone to nostalgia.
How to avoid perioperative visual loss following prone spinal surgery
Epstein, Nancy E.
Background: In a prior article, "Perioperative visual loss (POVL) following prone spinal surgery: A review," Epstein documented that postoperative visual loss (POVL) occurs in from 0.013% to 0.2% of spine procedures performed in the prone position. POVL is largely attributed to ischemic optic neuropathy (ION), central retinal artery occlusion (CRAO), cortical blindness (CB), direct compression (prone pillows/horseshoe, eye protectors), and rarely, acute angle closure glaucoma. Methods: Risk factors for ION include prolonged surgery, extensive fusions, anemia, hypotension, hypovolemia, diabetes, obesity, use of the Wilson frame, male sex, and microvascular pathology. CRAO may result from improper prone positioning (e.g., eye compression or rotation contributing to jugular/venous or carotid compression), while CB more typically results from both direct compression and obesity. Results: Several preventive/prophylactic measures should limit the risk of POVL. The routine use of an arterial line and continuous intraoperative monitoring document intraoperative hypotension/hypovolemia/anemia that can be immediately corrected with appropriate resuscitative measures. Application of a 3-pin head holder completely eliminates direct eye compression and maintains the neck in a neutral posture, thus avoiding rotation that can contribute to jugular/venous obstruction and/or inadvertent carotid compression. In addition, elevating the head 10° from the horizontal directly reduces intraocular pressure. Conclusions: The best way to avoid POVL following prone spine surgery is to prevent it. Routine use of an arterial line, intraoperative monitoring, a 3-pin head holder, and elevation of the head 10° from the horizontal should limit the risk of encountering POVL after spinal procedures performed in the prone position. PMID:27274406
Hypnotic responsiveness: expectancy, attitudes, fantasy proneness, absorption, and gender.
Green, Joseph P; Lynn, Steven Jay
This study examines the effect of providing information linking participants' attitudes toward hypnosis with later hypnotic performance. Using total scale scores from McConkey's Opinions About Hypnosis scale, as well as subscale scores, the authors found a weak association between attitudes and performance among 460 student participants; however, the correlation was unaffected by prehypnotic information specifically connecting attitudes and performance. A brief, 3-item measure of hypnotic expectancies generated the strongest correlation with hypnotic responsiveness. The authors also found that the association between fantasy proneness and hypnotizability was unaffected by the order of scale administration. Finally, the study highlighted gender differences across measures of fantasy proneness, absorption, expectancy, and hypnotizability.
Quantitative Expression Analysis in Brassica napus by Northern Blot Analysis and Reverse Transcription-Quantitative PCR in a Complex Experimental Setting.
Rumlow, Annekathrin; Keunen, Els; Klein, Jan; Pallmann, Philip; Riemenschneider, Anja; Cuypers, Ann; Papenbrock, Jutta
Analysis of gene expression is one of the major ways to better understand plant reactions to changes in environmental conditions. The comparison of many different factors influencing plant growth challenges the gene expression analysis for specific gene-targeted experiments, especially with regard to the choice of suitable reference genes. The aim of this study is to compare expression results obtained by Northern blot, semi-quantitative PCR and RT-qPCR, and to identify a reliable set of reference genes for oilseed rape (Brassica napus L.) suitable for comparing gene expression under complex experimental conditions. We investigated the influence of several factors such as sulfur deficiency, different time points during the day, varying light conditions, and their interaction on gene expression in oilseed rape plants. The expression of selected reference genes was indeed influenced under these conditions in different ways. Therefore, a recently developed algorithm, called GrayNorm, was applied to validate a set of reference genes for normalizing results obtained by Northern blot analysis. After careful comparison of the three methods mentioned above, Northern blot analysis seems to be a reliable and cost-effective alternative for gene expression analysis under a complex growth regime. For using this method in a quantitative way a number of references was validated revealing that for our experiment a set of three references provides an appropriate normalization. Semi-quantitative PCR was prone to many handling errors and difficult to control while RT-qPCR was very sensitive to expression fluctuations of the reference genes.
First order error corrections in common introductory physics experiments
NASA Astrophysics Data System (ADS)
Beckey, Jacob; Baker, Andrew; Aravind, Vasudeva; Clarion Team
As a part of introductory physics courses, students perform different standard lab experiments. Almost all of these experiments are prone to errors owing to factors like friction, misalignment of equipment, air drag, etc. Usually these types of errors are ignored by students and not much thought is paid to the source of these errors. However, paying attention to these factors that give rise to errors help students make better physics models and understand physical phenomena behind experiments in more detail. In this work, we explore common causes of errors in introductory physics experiment and suggest changes that will mitigate the errors, or suggest models that take the sources of these errors into consideration. This work helps students build better and refined physical models and understand physics concepts in greater detail. We thank Clarion University undergraduate student grant for financial support involving this project.
Transcription errors induce proteotoxic stress and shorten cellular lifespan.
Vermulst, Marc; Denney, Ashley S; Lang, Michael J; Hung, Chao-Wei; Moore, Stephanie; Moseley, M Arthur; Mosely, Arthur M; Thompson, J Will; Thompson, William J; Madden, Victoria; Gauer, Jacob; Wolfe, Katie J; Summers, Daniel W; Schleit, Jennifer; Sutphin, George L; Haroon, Suraiya; Holczbauer, Agnes; Caine, Joanne; Jorgenson, James; Cyr, Douglas; Kaeberlein, Matt; Strathern, Jeffrey N; Duncan, Mara C; Erie, Dorothy A
Transcription errors occur in all living cells; however, it is unknown how these errors affect cellular health. To answer this question, we monitor yeast cells that are genetically engineered to display error-prone transcription. We discover that these cells suffer from a profound loss in proteostasis, which sensitizes them to the expression of genes that are associated with protein-folding diseases in humans; thus, transcription errors represent a new molecular mechanism by which cells can acquire disease phenotypes. We further find that the error rate of transcription increases as cells age, suggesting that transcription errors affect proteostasis particularly in aging cells. Accordingly, transcription errors accelerate the aggregation of a peptide that is implicated in Alzheimer's disease, and shorten the lifespan of cells. These experiments reveal a previously unappreciated role for transcriptional fidelity in cellular health and aging.
''I'm Sitting Here Feeling Aphasic!'' A Study of Recurrent Perseverative Errors Elicited in Unimpaired Speakers
ERIC Educational Resources Information Center
Moses, Melanie S.; Nickels, Lyndsey A.; Sheard, Christine
In this study, the recurrent perseverative errors produced by 44 speakers without impairment were examined in picture naming and reading aloud tasks under a fast response deadline. The proportion of perseverative relative to non-perseverative errors was greater in picture naming, the more error-prone task, than in reading aloud. Additionally,…
Prone position in patients with acute respiratory distress syndrome
Setten, Mariano; Plotnikow, Gustavo Adrián; Accoce, Matías
Acute respiratory distress syndrome occupies a great deal of attention in intensive care units. Despite ample knowledge of the physiopathology of this syndrome, the focus in intensive care units consists mostly of life-supporting treatment and avoidance of the side effects of invasive treatments. Although great advances in mechanical ventilation have occurred in the past 20 years, with a significant impact on mortality, the incidence continues to be high. Patients with acute respiratory distress syndrome, especially the most severe cases, often present with refractory hypoxemia due to shunt, which can require additional treatments beyond mechanical ventilation, among which is mechanical ventilation in the prone position. This method, first recommended to improve oxygenation in 1974, can be easily implemented in any intensive care unit with trained personnel. Prone position has extremely robust bibliographic support. Various randomized clinical studies have demonstrated the effect of prone decubitus on the oxygenation of patients with acute respiratory distress syndrome measured in terms of the PaO2/FiO2 ratio, including its effects on increasing patient survival. The members of the Respiratory Therapists Committee of the Sociedad Argentina de Terapia Intensiva performed a narrative review with the objective of discovering the available evidence related to the implementation of prone position, changes produced in the respiratory system due to the application of this maneuver, and its impact on mortality. Finally, guidelines are suggested for decision-making. PMID:27925054
The Validity and Utility of the Depression Proneness Rating Scale.
ERIC Educational Resources Information Center
Zemore, Robert; And Others
The development of the Depression Proneness Rating Scale (DPRS) and three investigations into its reliability, validity, and factor structure are described. Subjects of all three studies were university undergraduates. The first study (n=100) found a stability coefficient of 0.82 for the DPRS over a test-retest (Time 1-Time 2) interval of 9 weeks.…
Prone position in patients with acute respiratory distress syndrome.
Setten, Mariano; Plotnikow, Gustavo Adrián; Accoce, Matías
Acute respiratory distress syndrome occupies a great deal of attention in intensive care units. Despite ample knowledge of the physiopathology of this syndrome, the focus in intensive care units consists mostly of life-supporting treatment and avoidance of the side effects of invasive treatments. Although great advances in mechanical ventilation have occurred in the past 20 years, with a significant impact on mortality, the incidence continues to be high. Patients with acute respiratory distress syndrome, especially the most severe cases, often present with refractory hypoxemia due to shunt, which can require additional treatments beyond mechanical ventilation, among which is mechanical ventilation in the prone position. This method, first recommended to improve oxygenation in 1974, can be easily implemented in any intensive care unit with trained personnel. Prone position has extremely robust bibliographic support. Various randomized clinical studies have demonstrated the effect of prone decubitus on the oxygenation of patients with acute respiratory distress syndrome measured in terms of the PaO2/FiO2 ratio, including its effects on increasing patient survival. The members of the Respiratory Therapists Committee of the Sociedad Argentina de Terapia Intensiva performed a narrative review with the objective of discovering the available evidence related to the implementation of prone position, changes produced in the respiratory system due to the application of this maneuver, and its impact on mortality. Finally, guidelines are suggested for decision-making.
The Social Antecedents of Anger Proneness in Young Adulthood
ERIC Educational Resources Information Center
Turner, R. Jay; Russell, David; Glover, Regan; Hutto, Pamela
Anger has been shown to be an important factor in occupational maladjustment, family conflict, physical and sexual assault, criminal behavior, and substance abuse. It has also been linked with such adverse health outcomes as hypertension, heart disease, and cancer. Focusing on anger proneness, conceptualized as a relatively enduring propensity to…
Pathogenesis of A-beta+ ketosis-prone diabetes
Technology Transfer Automated Retrieval System (TEKTRAN)
A-beta+ ketosis-prone diabetes (KPD) is an emerging syndrome of obesity, unprovoked ketoacidosis, reversible beta-cell dysfunction, and near-normoglycemic remission. We combined metabolomics with targeted kinetic measurements to investigate its pathophysiology. Fasting plasma fatty acids, acylcarnit...
Prone position craniotomy in pregnancy without fetal heart rate monitoring.
Jacob, Jean; Alexander, Ashish; Philip, Shoba; Thomas, Anoop
A pregnant patient in second trimester scheduled for posterior fossa craniotomy in prone position is a challenge for the anesthesiologist. Things to consider are physiological changes during pregnancy, non-obstetric surgery in pregnant patients, neuroanesthetic principles, effects of prone positioning, and need for fetal heart rate (FHR) monitoring. We have described the anesthetic management of this case and discussed intra-operative FHR monitoring including controversies about its role, indications, and various options available as per fetal gestational age. In our case we attempted intermittent intra-operative FHR monitoring to optimize maternal positioning and fetal oxygenation even though the fetus was pre-viable. However the attempt was abandoned due to practical difficulties with prone positioning. Patient made good neurological recovery following the procedure and delivered a healthy term baby 4 months later. Decisions regarding fetal monitoring should be individualized based on viability of the fetus and feasibility of emergency cesarean delivery. Good communication between a multidisciplinary team involving neurosurgeon, anesthesiologist, obstetrician, and neonatologist is important for a successful outcome for mother and fetus. We conclude that prone position neurosurgery can safely be carried out in a pregnant patient with pre-viable fetus without FHR monitoring.
Target Uncertainty Mediates Sensorimotor Error Correction
Vijayakumar, Sethu; Wolpert, Daniel M.
Human movements are prone to errors that arise from inaccuracies in both our perceptual processing and execution of motor commands. We can reduce such errors by both improving our estimates of the state of the world and through online error correction of the ongoing action. Two prominent frameworks that explain how humans solve these problems are Bayesian estimation and stochastic optimal feedback control. Here we examine the interaction between estimation and control by asking if uncertainty in estimates affects how subjects correct for errors that may arise during the movement. Unbeknownst to participants, we randomly shifted the visual feedback of their finger position as they reached to indicate the center of mass of an object. Even though participants were given ample time to compensate for this perturbation, they only fully corrected for the induced error on trials with low uncertainty about center of mass, with correction only partial in trials involving more uncertainty. The analysis of subjects' scores revealed that participants corrected for errors just enough to avoid significant decrease in their overall scores, in agreement with the minimal intervention principle of optimal feedback control. We explain this behavior with a term in the loss function that accounts for the additional effort of adjusting one's response. By suggesting that subjects' decision uncertainty, as reflected in their posterior distribution, is a major factor in determining how their sensorimotor system responds to error, our findings support theoretical models in which the decision making and control processes are fully integrated. PMID:28129323
Target Uncertainty Mediates Sensorimotor Error Correction.
Acerbi, Luigi; Vijayakumar, Sethu; Wolpert, Daniel M
Human movements are prone to errors that arise from inaccuracies in both our perceptual processing and execution of motor commands. We can reduce such errors by both improving our estimates of the state of the world and through online error correction of the ongoing action. Two prominent frameworks that explain how humans solve these problems are Bayesian estimation and stochastic optimal feedback control. Here we examine the interaction between estimation and control by asking if uncertainty in estimates affects how subjects correct for errors that may arise during the movement. Unbeknownst to participants, we randomly shifted the visual feedback of their finger position as they reached to indicate the center of mass of an object. Even though participants were given ample time to compensate for this perturbation, they only fully corrected for the induced error on trials with low uncertainty about center of mass, with correction only partial in trials involving more uncertainty. The analysis of subjects' scores revealed that participants corrected for errors just enough to avoid significant decrease in their overall scores, in agreement with the minimal intervention principle of optimal feedback control. We explain this behavior with a term in the loss function that accounts for the additional effort of adjusting one's response. By suggesting that subjects' decision uncertainty, as reflected in their posterior distribution, is a major factor in determining how their sensorimotor system responds to error, our findings support theoretical models in which the decision making and control processes are fully integrated.
Optical measurement of dimensional parameters of the breast with subjects in prone position
Roessler, Ann-Christin; Althoff, Felix; Jaeger, Florian; Kalender, Willi; Wenkel, Evelyn
Abstract. Various applications require information on breast parameters, such as breast length and volume. An optical system was designed and tested for measuring these parameters with subjects in a prone position. The study results were used for optimizing patient positioning and handling for a future breast computed tomography (BCT) system. Measurements were conducted using an optical measurement system. To test the functionality and accuracy of the system, measurements were performed using reference phantoms. Additionally, 20 women and 5 men were examined to calculate breast parameters in alternative positions and breathing states. The results of the optical measurements were compared with magnetic resonance imaging (MRI) measurements. Volume and length of the reference phantoms were determined with errors below 2%. The patient study demonstrated a mean breast volume of 530.7 ml for women during normal breathing. During an exhalation state, breast volume increased significantly by 17.7 ml in comparison with normal breathing. Differences with MRI measurements were found to be 3% for breast length and 9% for breast volume on average. The proposed optical measurement system was found to be suitable for measuring the dimensional parameters of the breast in a prone position and provides a tool for evaluating breast coverage for BCT. PMID:26240833
Perioperative visual loss following prone spinal surgery: A review
Epstein, Nancy E.
Background: Postoperative visual loss (POVL) following prone spine surgery occurs in from 0.013% to 1% of cases and is variously attributed to ischemic optic neuropathy (ION: anterior ION or posterior ION [reported in 1.9/10,000 cases: constitutes 89% of all POVL cases], central retinal artery occlusion [CRAO], central retinal vein occlusion [CRVO], cortical blindness [CB], direct compression [horseshoe, prone pillows, and eye protectors Dupaco Opti-Gard]), and acute angle closure glaucoma (AACG). Methods: Risk factors for ION include prolonged operative times, long-segment spinal instrumentation, anemia, intraoperative hypotension, diabetes, obesity, male sex, using the Wilson frame, microvascular pathology, decreased the percent of colloid administration, and extensive intraoperative blood loss. Risk factors for CRAO more typically include improper positioning during the surgery (e.g., cervical rotation), while those for CB included prone positioning and obesity. Results: POVL may be avoided by greater utilization of crystalloids versus colloids, administration of α-2 agonists (e.g., decreases intraocular pressure), avoidance of catecholamines (e.g., avoid vasoconstrictors), avoiding intraoperative hypotension, and averting anemia. Patients with glaucoma or glaucoma suspects may undergo preoperative evaluation by ophthalmologists to determine whether they require prophylactic treatment prior to prone spinal surgery and whether and if prophylactic treatment is warranted. Conclusions: The best way to avoid POVL is to recognize its multiple etiologies and limit the various risk factors that contribute to this devastating complication of prone spinal surgery. Furthermore, routinely utilizing a 3-pin head holder will completely avoid ophthalmic compression, while maintaining the neck in a neutral posture, largely avoiding the risk of jugular vein and/or carotid artery compromise and thus avoiding increasing IOP. PMID:27274409
Hypothesis testing in an errors-in-variables model with heteroscedastic measurement errors.
de Castro, Mário; Galea, Manuel; Bolfarine, Heleno
In many epidemiological studies it is common to resort to regression models relating incidence of a disease and its risk factors. The main goal of this paper is to consider inference on such models with error-prone observations and variances of the measurement errors changing across observations. We suppose that the observations follow a bivariate normal distribution and the measurement errors are normally distributed. Aggregate data allow the estimation of the error variances. Maximum likelihood estimates are computed numerically via the EM algorithm. Consistent estimation of the asymptotic variance of the maximum likelihood estimators is also discussed. Test statistics are proposed for testing hypotheses of interest. Further, we implement a simple graphical device that enables an assessment of the model's goodness of fit. Results of simulations concerning the properties of the test statistics are reported. The approach is illustrated with data from the WHO MONICA Project on cardiovascular disease.
The application of Aronson's taxonomy to medication errors in nursing.
Johnson, Maree; Young, Helen
Medication administration is a frequent nursing activity that is prone to error. In this study of 318 self-reported medication incidents (including near misses), very few resulted in patient harm-7% required intervention or prolonged hospitalization or caused temporary harm. Aronson's classification system provided an excellent framework for analysis of the incidents with a close connection between the type of error and the change strategy to minimize medication incidents. Taking a behavioral approach to medication error classification has provided helpful strategies for nurses such as nurse-call cards on patient lockers when patients are absent and checking of medication sign-off by outgoing and incoming staff at handover.
Enhancing disaster management by mapping disaster proneness and preparedness.
Mishra, Vishal; Fuloria, Sanjay; Bisht, Shailendra Singh
The focus of most disaster management programmes is to deploy resources-physical and human-from outside the disaster zone. This activity can produce a delay in disaster mitigation and recovery efforts, and a consequent loss of human lives and economic resources. It may be possible to expedite recovery and prevent loss of life by mapping out disaster proneness and the availability of resources in advance. This study proposes the development of two indices to do so. The Indian census data of 2001 is used to develop a methodology for creating one index on disaster proneness and one on resourcefulness for administrative units (tehsils). Findings reveal that tehsil residents face an elevated risk of disaster and that they are also grossly under-prepared for such events. The proposed indices can be used to map regional service provision facilities and to assist authorities in evaluating immediate, intermediate, and long-term disaster recovery needs and resource requirements.
Evaluating fatigue in lupus-prone mice: preliminary assessments.
Meeks, Allison; Larson, Susan J
Fatigue is a debilitating condition suffered by many as the result of chronic disease, yet relatively little is known about its biological basis or how to effectively manage its effects. This study sought to evaluate chronic fatigue by using lupus-prone mice and testing them at three different time periods. Lupus-prone mice were chosen because fatigue affects over half of patients with Systemic Lupus Erythematosus. Eleven MLR⁺/(+) (genetic controls) and twelve MLR/MpJ-Fas
Prone positioning reduces severe pushing behavior: three case studies
Fujino, Yuji; Amimoto, Kazu; Sugimoto, Satoshi; Fukata, Kazuhiro; Inoue, Masahide; Takahashi, Hidetoshi; Makita, Shigeru
[Purpose] Pushing behavior is classically described as a disorder of body orientation in the coronal plane. Most interventions for pushing behavior have focused on correcting the deviation in vertical perception. However, pushing behavior seems to involve erroneous movements associated with excessive motor output by the non-paretic limbs and trunk. The present study aimed to inhibit muscular hyper-activity by placing the non-paretic limbs and trunk in the prone position. [Subjects and Methods] The subjects of the present study were 3 acute stroke patients with severe pushing behavior. The study consisted of the following 3 phases: baseline, intervention, and follow-up. In addition to conventional therapy, patients received relaxation therapy in the prone position for 10 minutes a day over 2 days. The severity of pushing behavior was assessed using the scale for contraversive pushing, and truncal balance was evaluated using the trunk control test. These assessments were performed before and after the baseline phase, and after the intervention and follow-up phases. [Results] At the baseline phase, both scores were poor. Both scores improved after the intervention and follow-up phases, and all the patients could sit independently. [Conclusion] Relaxation therapy in the prone position might ameliorate pushing behavior and impaired truncal balance. PMID:27799722
NASA Astrophysics Data System (ADS)
Konrad, Regina; Busch, Ulrich
Die vielfältigen Anwendungsmöglichkeiten der Polymerasekettenreaktion (polymerase chain reaction, PCR) machen sie zu einer der wichtigsten und am häufigsten eingesetzten Methoden in der molekularbiologischen Forschung und Diagnostik. Für diese Technologie wurde der Erfinder der Methode, Kary Mullis, 1993 mit dem Nobelpreis ausgezeichnet. Die PCR erlaubt einen hochsensitiven und spezifischen in-vitro-Nachweis von Desoxyribonukleinsäuren (DNA), da im Zuge der Reaktion Sequenzabschnitte gezielt vermehrt werden. Innerhalb weniger Stunden können aus einem einzigen Zielmolekül 1012 identische Moleküle entstehen [1].
A PCR based protocol for detecting indel mutations induced by TALENs and CRISPR/Cas9 in zebrafish.
Yu, Chuan; Zhang, Yaguang; Yao, Shaohua; Wei, Yuquan
Genome editing techniques such as the zinc-finger nucleases (ZFNs), transcription activator-like effecter nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system Cas9 can induce efficient DNA double strand breaks (DSBs) at the target genomic sequence and result in indel mutations by the error-prone non-homologous end joining (NHEJ) DNA repair system. Several methods including sequence specific endonuclease assay, T7E1 assay and high resolution melting curve assay (HRM) etc have been developed to detect the efficiency of the induced mutations. However, these assays have some limitations in that they either require specific sequences in the target sites or are unable to generate sequencing-ready mutant DNA fragments or unable to distinguish induced mutations from natural nucleotide polymorphism. Here, we developed a simple PCR-based protocol for detecting indel mutations induced by TALEN and Cas9 in zebrafish. We designed 2 pairs of primers for each target locus, with one putative amplicon extending beyond the putative indel site and the other overlapping it. With these primers, we performed a qPCR assay to efficiently detect the frequencies of newly induced mutations, which was accompanied with a T-vector-based colony analysis to generate single-copy mutant fragment clones for subsequent DNA sequencing. Thus, our work has provided a very simple, efficient and fast assay for detecting induced mutations, which we anticipate will be widely used in the area of genome editing.
Melatonin improves inflammation processes in liver of senescence-accelerated prone male mice (SAMP8).
Cuesta, Sara; Kireev, Roman; Forman, Katherine; García, Cruz; Escames, Germaine; Ariznavarreta, Carmen; Vara, Elena; Tresguerres, Jesús A F
Aging is associated with an increase in oxidative stress and inflammation. The aim of this study was to investigate the effect of aging on various physiological parameters related to inflammation in livers obtained from two types of male mice models: Senescence-accelerated prone (SAMP8) and senescence-accelerated-resistant (SAMR1) mice, and to study the influence of the administration of melatonin (1mg/kg/day) for one month on old SAMP8 mice on these parameters. The parameters studied have been the mRNA expression of TNF-α, iNOS, IL-1β, HO-1, HO-2, MCP1, NFkB1, NFkB2, NFkB protein or NKAP and IL-10. All have been measured by real-time reverse transcription polymerase chain reaction RT-PCR. Furthermore we analyzed the protein expression of TNF-α, iNOS, IL-1β, HO-1, HO-2, and IL-10 by Western-blot. Aging increased oxidative stress and inflammation especially in the liver of SAMP8 mice. Treatment with melatonin decreased the mRNA expression of TNF-α, IL-1β, HO (HO-1 and HO-2), iNOS, MCP1, NFκB1, NFκB2 and NKAP in old male mice. The protein expression of TNF-α, IL-1β was also decreased and IL-10 increased with melatonin treatment and no significant differences were observed in the rest of parameters analyzed. The present study showed that aging was related to inflammation in livers obtained from old male senescence prone mice (SAMP8) and old male senescence resistant mice (SAMR1) being the alterations more evident in the former. Exogenous administration of melatonin was able to reduce inflammation.
Error Rate Comparison during Polymerase Chain Reaction by DNA Polymerase
McInerney, Peter; Adams, Paul; Hadi, Masood Z.
As larger-scale cloning projects become more prevalent, there is an increasing need for comparisons among high fidelity DNA polymerases used for PCR amplification. All polymerases marketed for PCR applications are tested for fidelity properties (i.e., error rate determination) by vendors, and numerous literature reports have addressed PCR enzyme fidelity. Nonetheless, it is often difficult to make direct comparisons among different enzymes due to numerous methodological and analytical differences from study to study. We have measured the error rates for 6 DNA polymerases commonly used in PCR applications, including 3 polymerases typically used for cloning applications requiring high fidelity. Errormore » rate measurement values reported here were obtained by direct sequencing of cloned PCR products. The strategy employed here allows interrogation of error rate across a very large DNA sequence space, since 94 unique DNA targets were used as templates for PCR cloning. The six enzymes included in the study, Taq polymerase, AccuPrime-Taq High Fidelity, KOD Hot Start, cloned Pfu polymerase, Phusion Hot Start, and Pwo polymerase, we find the lowest error rates with Pfu , Phusion, and Pwo polymerases. Error rates are comparable for these 3 enzymes and are >10x lower than the error rate observed with Taq polymerase. Mutation spectra are reported, with the 3 high fidelity enzymes displaying broadly similar types of mutations. For these enzymes, transition mutations predominate, with little bias observed for type of transition.« less
Recursive construction and error correction of DNA molecules and libraries from synthetic and natural DNA.
Yehezkel, Tuval Ben; Linshiz, Gregory; Kaplan, Shai; Gronau, Ilan; Ravid, Sivan; Adar, Rivka; Shapiro, Ehud
Making error-free, custom DNA assemblies from potentially faulty building blocks is a fundamental challenge in synthetic biology. Here, we show how recursion can be used to address this challenge using a recursive procedure that constructs error-free DNA molecules and their libraries from error-prone synthetic oligonucleotides and naturally existing DNA. Specifically, we describe how divide and conquer (D&C), the quintessential recursive problem-solving technique, is applied in silico to divide target DNA sequences into overlapping, albeit error prone, oligonucleotides, and how recursive construction is applied in vitro to combine them to form error-prone DNA molecules. To correct DNA sequence errors, error-free fragments of these molecules are then identified, extracted, and used as new, typically longer and more accurate, inputs to another iteration of the recursive construction procedure; the entire process repeats until an error-free target molecule is formed. The method allows combining synthetic and natural DNA fragments into error-free designer DNA libraries, thus providing a foundation for the design and construction of complex synthetic DNA assemblies.
44 CFR 60.22 - Planning considerations for flood-prone areas.
Code of Federal Regulations, 2010 CFR
... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Planning considerations for...., Mudflow)-Prone and Flood-Related Erosion-Prone Areas § 60.22 Planning considerations for flood-prone areas.... In the event of an overall drainage basin plan, provide that the flood carrying capacity within...
Prone Breast Intensity Modulated Radiation Therapy: 5-Year Results
Osa, Etin-Osa O.; DeWyngaert, Keith; Roses, Daniel; Speyer, James; Guth, Amber; Axelrod, Deborah; Fenton Kerimian, Maria; Goldberg, Judith D.; Formenti, Silvia C.
Purpose: To report the 5-year results of a technique of prone breast radiation therapy delivered by a regimen of accelerated intensity modulated radiation therapy with a concurrent boost to the tumor bed. Methods and Materials: Between 2003 and 2006, 404 patients with stage I-II breast cancer were prospectively enrolled into 2 consecutive protocols, institutional trials 03-30 and 05-181, that used the same regimen of 40.5 Gy/15 fractions delivered to the index breast over 3 weeks, with a concomitant daily boost to the tumor bed of 0.5 Gy (total dose 48 Gy). All patients were treated after segmental mastectomy and had negative margins and nodal assessment. Patients were set up prone: only if lung or heart volumes were in the field was a supine setup attempted and chosen if found to better spare these organs. Results: Ninety-two percent of patients were treated prone, 8% supine. Seventy-two percent had stage I, 28% stage II invasive breast cancer. In-field lung volume ranged from 0 to 228.27 cm{sup 3}, mean 19.65 cm{sup 3}. In-field heart volume for left breast cancer patients ranged from 0 to 21.24 cm{sup 3}, mean 1.59 cm{sup 3}. There was no heart in the field for right breast cancer patients. At a median follow-up of 5 years, the 5-year cumulative incidence of isolated ipsilateral breast tumor recurrence was 0.82% (95% confidence interval [CI] 0.65%-1.04%). The 5-year cumulative incidence of regional recurrence was 0.53% (95% CI 0.41%-0.69%), and the 5-year overall cumulative death rate was 1.28% (95% CI 0.48%-3.38%). Eighty-two percent (95% CI 77%-85%) of patients judged their final cosmetic result as excellent/good. Conclusions: Prone accelerated intensity modulated radiation therapy with a concomitant boost results in excellent local control and optimal sparing of heart and lung, with good cosmesis. Radiation Therapy Oncology Group protocol 1005, a phase 3, multi-institutional, randomized trial is ongoing and is evaluating the equivalence of a similar dose and
DNA deamination enables direct PCR amplification of the cystatin B (CSTB) gene-associated dodecamer repeat expansion in myoclonus epilepsy type Unverricht-Lundborg.
Weinhaeusel, Andreas; Morris, Michael A; Antonarakis, Stylianos E; Haas, Oskar A
The Unverricht-Lundborg type of progressive myoclonus epilepsy (EPM1) is an autosomal recessive disorder that is caused by the dysfunction of the cystatin B (CSTB) gene product. In the vast majority of affected cases, mRNA transcription is impaired by a biallelic expansion of a dodecamer repeat within the 5'-untranslated region of the respective gene. Since this minisatellite contains exclusively G and C nucleotides, direct PCR analysis of allele expansion is extremely difficult and error prone. To circumvent these problems, we have developed a PCR assay that is based on the deamination of the DNA prior to amplification. We have developed a method based on PCR after DNA deamination of the GC-rich repeat region, which improves the PCR condition to such an extent that we were not only able to reliably amplify expanded alleles of affected individuals (homozygotes and compound heterozygotes), but also the two alleles of full mutation carriers, whose analysis is particularly difficult because of PCR bias and heteroduplex formation between the two alleles. We used promoter- and repeat-specific primer combinations to investigate whether dodecamer repeat expansion concurs with de novo methylation of the CSTB gene promoter in a similar fashion to other repeat expansion syndromes. We confirmed previous evidence obtained by HpaII digestion and Southern blot analysis that both the promoter and the repeat regions are unmethylated, in both healthy and affected individuals. Thus, in contrast to certain trinucleotide repeat expansion-associated diseases, such as fragile X syndrome (FRAXA) and myotonic dystrophy, methylation analyses can not be utilized for indirect diagnostic testing.
[Reactance proneness, collectivism, uniqueness, and resistance to persuasion].
Imajo, Shuzo
This study examined the reliability and validity of Japanese psychological reactance scales. A total of 167 undergraduates completed a questionnaire of Therapeutic Reactance Scale (TRS), the Hong Reactance Scale (HRS), the Uniqueness Scale, and the Collectivism Scale. They also received messages involving three persuasion situations that were either high or low in terms of threat, and were asked to describe their reactions to them. The author categorized the reactions into three: acceptance, indirect resistance, and direct resistance. Reliabilities of the reactance scales were satisfactory. Their scores positively correlated with uniqueness scores, and negatively with collectivism scores. Those high on reactance proneness were less persuaded in two of the three situations. But in the third, an HRS by threat interaction was observed, indicating that only those who were high on reactance proneness under the high-threat condition showed resistance to persuasion. These results suggest that the Japanese versions of reactance scale were reliable and valid. However, the assertiveness aspect of TRS may not be appropriate for the definition of reactance. The influence of culture on psychological reactance was also discussed.
Study on proneness of spontaneous combustion of macerals
Zhang, Y.G.; Li, F.; Tang, X.Y.; Xie, K.C.
Pure macerals from brown coal to gas coal were separated from coalfields of Pingzhuang, Liaoyuan, Fuxin, Fushun, Changguang Hunyuan and Tangcun, and effect of macerals on spontaneous combustion was recently investigated with ignition temperature and index gas technique. Three kinds of maceral group with same rank have different ignition temperature and proneness of spontaneous combustion. Vitrinite group has the lowest ignition temperature, it is the most liable to spontaneous combustion, and the proneness of spontaneous combustion of coal increases with the increases of vitrain content, fusinite group has the highest ignition temperature, is least liable; Exinite group is in the middle. Gaseous products of three kinds of maceral group such as CO, C{sub 2}H{sub 4} and C{sub 3}H{sub 6} which are used as index gas have different rates of formation during oxidation; the vitrinite group is higher than others. Vitrinite group with more active site is easy to oxidize at low temperature. Exinite group with the lowest aromaticity and many aliphatic structure present in the aromatic layers is of steady chemical properties, so it is least liable to oxidize at low temperature. Fusinite group with the short CH{sub 3} and/or CH{sub 2} side chain and fewer active sites in the aromatic rings is inert in chemical properties and most difficult to oxidize at low temperature.
Topological quantum computing with a very noisy network and local error rates approaching one percent.
Nickerson, Naomi H; Li, Ying; Benjamin, Simon C
A scalable quantum computer could be built by networking together many simple processor cells, thus avoiding the need to create a single complex structure. The difficulty is that realistic quantum links are very error prone. A solution is for cells to repeatedly communicate with each other and so purify any imperfections; however prior studies suggest that the cells themselves must then have prohibitively low internal error rates. Here we describe a method by which even error-prone cells can perform purification: groups of cells generate shared resource states, which then enable stabilization of topologically encoded data. Given a realistically noisy network (≥10% error rate) we find that our protocol can succeed provided that intra-cell error rates for initialisation, state manipulation and measurement are below 0.82%. This level of fidelity is already achievable in several laboratory systems.
Elliott, C.J.; McVey, B. ); Quimby, D.C. )
The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.
Metabolism - inborn errors of ... Bodamer OA. Approach to inborn errors of metabolism. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 205. Rezvani I, Rezvani G. An ...
Systematic errors in strong lens modeling
NASA Astrophysics Data System (ADS)
Johnson, Traci Lin; Sharon, Keren; Bayliss, Matthew B.
The lensing community has made great strides in quantifying the statistical errors associated with strong lens modeling. However, we are just now beginning to understand the systematic errors. Quantifying these errors is pertinent to Frontier Fields science, as number counts and luminosity functions are highly sensitive to the value of the magnifications of background sources across the entire field of view. We are aware that models can be very different when modelers change their assumptions about the parameterization of the lensing potential (i.e., parametric vs. non-parametric models). However, models built while utilizing a single methodology can lead to inconsistent outcomes for different quantities, distributions, and qualities of redshift information regarding the multiple images used as constraints in the lens model. We investigate how varying the number of multiple image constraints and available redshift information of those constraints (ex., spectroscopic vs. photometric vs. no redshift) can influence the outputs of our parametric strong lens models, specifically, the mass distribution and magnifications of background sources. We make use of the simulated clusters by M. Meneghetti et al. and the first two Frontier Fields clusters, which have a high number of multiply imaged galaxies with spectroscopically-measured redshifts (or input redshifts, in the case of simulated clusters). This work will not only inform upon Frontier Field science, but also for work on the growing collection of strong lensing galaxy clusters, most of which are less massive and are capable of lensing a handful of galaxies, and are more prone to these systematic errors.
When soft controls get slippery: User interfaces and human error
Stubler, W.F.; O`Hara, J.M.
Many types of products and systems that have traditionally featured physical control devices are now being designed with soft controls--input formats appearing on computer-based display devices and operated by a variety of input devices. A review of complex human-machine systems found that soft controls are particularly prone to some types of errors and may affect overall system performance and safety. This paper discusses the application of design approaches for reducing the likelihood of these errors and for enhancing usability, user satisfaction, and system performance and safety.
ERIC Educational Resources Information Center
Kearsley, Greg P.
This paper discusses and provides some preliminary data on errors in APL programming. Data were obtained by analyzing listings of 148 complete and partial APL sessions collected from student terminal rooms at the University of Alberta. Frequencies of errors for the various error messages are tabulated. The data, however, are limited because they…
The present study examined the roles of shame- and guilt-proneness as mediators of associations between general causality orientations and depressive symptoms. We expected autonomy would be associated with less depressive symptoms based on higher guilt-proneness and lower shame-proneness, whereas control would be associated with more depressive symptoms based on lower guilt-proneness and higher shame-proneness. Undergraduates (N = 354) completed assessments of general causality orientations, shame- and guilt-proneness, and depressive symptoms in exchange for extra credit. Results of mediation analyses were generally supportive of the framework indicating that shame- and guilt-proneness mediate associations between self-determination and depressive symptoms. Autonomy was indirectly associated with less depressive symptoms through positive associations with guilt-proneness, in spite of unexpected positive associations with shame-proneness. Control and impersonal orientation were indirectly associated with more depressive symptoms through positive associations with shame-proneness. Results extend previous research relating self-determination to mental health in providing preliminary support suggesting that individual differences in self-determination facilitate differential tendencies in experiencing guilt and shame.
Jerky driving--An indicator of accident proneness?
Bagdadi, Omar; Várhelyi, András
This study uses continuously logged driving data from 166 private cars to derive the level of jerks caused by the drivers during everyday driving. The number of critical jerks found in the data is analysed and compared with the self-reported accident involvement of the drivers. The results show that the expected number of accidents for a driver increases with the number of critical jerks caused by the driver. Jerk analyses make it possible to identify safety critical driving behaviour or "accident prone" drivers. They also facilitate the development of safety measures such as active safety systems or advanced driver assistance systems, ADAS, which could be adapted for specific groups of drivers or specific risky driving behaviour.
Quantitative electroencephalography as a biomarker for proneness toward developing psychosis.
Fuggetta, Giorgio; Bennett, Matthew A; Duke, Philip A; Young, Andrew M J
The fully dimensional approach to the relationship between schizotypal personality traits and schizophrenia describes schizotypy as a continuum throughout the general population ranging from low schizotypy (LoS) and psychological health to high schizotypy (HiS) and psychosis-proneness. However, no biological markers have yet been discovered that reliably quantify an individual's degree of schizotypy and/or psychosis. This study aimed to evaluate quantitative electroencephalographic (qEEG) measures of power spectra as potential biomarkers of the proneness towards the development of psychosis in schizotypal individuals. The resting-state oscillatory brain dynamics under eyes-closed condition from 16 LoS and 16 HiS individuals were analysed for qEEG measures of background rhythm frequency, relative power in δ, θ, low-α, high-α, low-β, high-β and low-γ frequency bands, and the high-temporal cross-correlation of power spectra between low- and high-frequency bands observed by averaging signals from whole-head EEG electrodes. HiS individuals at rest locked the thalamocortical loop in the low-α band at a lower-frequency oscillation and displayed an abnormally high level of neural synchronisation. In addition, the high-α band was found to be positively correlated with both the high-β and low-γ bands unlike LoS individuals, indicating widespread thalamocortical resonance in HiS individuals. The increase of regional alpha oscillations in HiS individuals suggests abnormal high-level attention, whereas the pattern of correlation between frequency bands resembles the thalamocortical dysrhythmia phenomenon which underlies the symptomatology of a variety of neuropsychiatric disorders including schizophrenia. These qEEG biomarkers may aid clinicians in identifying HiS individuals with a high-risk of developing psychosis.
Skills, rules and knowledge in aircraft maintenance: errors in context
NASA Technical Reports Server (NTRS)
Hobbs, Alan; Williamson, Ann
Automatic or skill-based behaviour is generally considered to be less prone to error than behaviour directed by conscious control. However, researchers who have applied Rasmussen's skill-rule-knowledge human error framework to accidents and incidents have sometimes found that skill-based errors appear in significant numbers. It is proposed that this is largely a reflection of the opportunities for error which workplaces present and does not indicate that skill-based behaviour is intrinsically unreliable. In the current study, 99 errors reported by 72 aircraft mechanics were examined in the light of a task analysis based on observations of the work of 25 aircraft mechanics. The task analysis identified the opportunities for error presented at various stages of maintenance work packages and by the job as a whole. Once the frequency of each error type was normalized in terms of the opportunities for error, it became apparent that skill-based performance is more reliable than rule-based performance, which is in turn more reliable than knowledge-based performance. The results reinforce the belief that industrial safety interventions designed to reduce errors would best be directed at those aspects of jobs that involve rule- and knowledge-based performance.
SU-E-J-21: Setup Variability of Colorectal Cancer Patients Treated in the Prone Position and Dosimetric Comparison with the Supine Position
Kim, A; Foster, J; Chu, W; Karotki, A
Purpose: Many cancer centers treat colorectal patients in the prone position on a belly board to minimize dose to the small bowel. That may potentially Result in patient setup instability with corresponding impact on dose delivery accuracy for highly conformal techniques such as IMRT/VMAT. Two aims of this work are 1) to investigate setup accuracy of rectum patients treated in the prone position on a belly board using CBCT and 2) to evaluate dosimetric impact on bladder and small bowel of treating rectum patients in supine vs. prone position. Methods: For the setup accuracy study, 10 patients were selected. Weekly CBCTs were acquired and matched to bone. The CBCT-determined shifts were recorded. For the dosimetric study, 7 prone-setup patients and 7 supine-setup patients were randomly selected from our clinical database. Various clinically relevant dose volume histogram values were recorded for the small bowel and bladder. Results: The CBCT-determined rotational shifts had a wide variation. For the dataset acquired at the time of this writing, the ranges of rotational setup errors for pitch, roll, and yaw were [−3.6° 4.7°], [−4.3° 3.2°], and [−1.4° 1.4°]. For the dosimetric study: the small bowel V(45Gy) and mean dose for the prone position was 5.6±12.1% and 18.4±6.2Gy (ranges indicate standard deviations); for the supine position the corresponding dose values were 12.9±15.8% and 24.7±8.8Gy. For the bladder, the V(30Gy) and mean dose for prone position were 68.7±12.7% and 38.4±3.3Gy; for supine position these dose values were 77.1±13.7% and 40.7±3.1Gy. Conclusion: There is evidence of significant rotational instability in the prone position. The OAR dosimetry study indicates that there are some patients that may still benefit from the prone position, though many patients can be safely treated supine.
Assessment of trichloroethylene (TCE) exposure in murine strains genetically-prone and non-prone to develop autoimmune disease.
Keil, Deborah E; Peden-Adams, Margie M; Wallace, Stacy; Ruiz, Phillip; Gilkeson, Gary S
There is increasing laboratory and epidemiologic evidence relating exposure to trichloroethylene (TCE) with autoimmune disease including scleroderma and lupus. New Zealand Black/New Zealand White (NZBWF1) and B6C3F1 mice were exposed to TCE (0, 1, 400 or 14,000 ppb) via drinking water for 27 or 30 weeks, respectively. NZBWF1 mice spontaneously develop autoimmune disease while B6C3F1 mice, a standard strain used in immunotoxicology testing, are not genetically prone to develop autoimmune disease. During the TCE exposure period, serum levels of total IgG, and autoantibodies (anti-ssDNA, -dsDNA, and -glomerular antigen [GA]) were monitored. At the termination of the study, renal pathology, natural killer (NK) cell activity, total IgG levels, autoantibody production, T-cell activation, and lymphocytic proliferative responses were evaluated. TCE did not alter NK cell activity, or T- and B-cell proliferation in either strain. Numbers of activated T-cells (CD4+/CD44+) were increased in the B6C3F1 mice but not in the NZBWF1 mice. Renal pathology, as indicated by renal score, was significantly increased in the B6C3F1, but not in the NZBWF1 mice. Serum levels of autoantibodies to dsDNA and ssDNA were increased at more time points in B6C3F1, as compared to the NZBWF1 mice. Anti-GA autoantibodies were increased by TCE treatment in early stages of the study in NZBWF1 mice, but by 23 weeks of age, control levels were comparable to those of TCE-exposed animals. Serum levels anti-GA autoantibodies in B6C3F1 were not affected by TCE exposure. Overall, these data suggest that TCE did not contribute to the progression of autoimmune disease in autoimmune-prone mice during the period of 11-36 weeks of age, but rather lead to increased expression of markers associated with autoimmune disease in a non-genetically prone mouse strain.
Larson, Michael J; Fair, Joseph E; Good, Daniel A; Baldwin, Scott A
Recent research suggests a relationship between empathy and error processing. Error processing is an evaluative control function that can be measured using post-error response time slowing and the error-related negativity (ERN) and post-error positivity (Pe) components of the event-related potential (ERP). Thirty healthy participants completed two measures of empathy, the Interpersonal Reactivity Index (IRI) and the Empathy Quotient (EQ), and a modified Stroop task. Post-error slowing was associated with increased empathic personal distress on the IRI. ERN amplitude was related to overall empathy score on the EQ and the fantasy subscale of the IRI. The Pe and measures of empathy were not related. Results remained consistent when negative affect was controlled via partial correlation, with an additional relationship between ERN amplitude and empathic concern on the IRI. Findings support a connection between empathy and error processing mechanisms.
Error resiliency of distributed video coding in wireless video communication
NASA Astrophysics Data System (ADS)
Ye, Shuiming; Ouaret, Mourad; Dufaux, Frederic; Ansorge, Michael; Ebrahimi, Touradj
Distributed Video Coding (DVC) is a new paradigm in video coding, based on the Slepian-Wolf and Wyner-Ziv theorems. DVC offers a number of potential advantages: flexible partitioning of the complexity between the encoder and decoder, robustness to channel errors due to intrinsic joint source-channel coding, codec independent scalability, and multi-view coding without communications between the cameras. In this paper, we evaluate the performance of DVC in an error-prone wireless communication environment. We also present a hybrid spatial and temporal error concealment approach for DVC. Finally, we perform a comparison with a state-of-the-art AVC/H.264 video coding scheme in the presence of transmission errors.
Characterization of genetic deletions in Becker muscular dystrophy using monoclonal antibodies against a deletion-prone region of dystrophin
Thanh, L.T.; Man, Nguyen Thi; Morris, G.E.
We have produced a new panel of 20 monoclonal antibodies (mAbs) against a region of the dystrophin protein corresponding to a deletion-prone region of the Duchenne muscular dystrophy gene (exons 45-50). We show that immunohistochemistry or Western blotting with these {open_quotes}exon-specific{close_quotes} mAbs can provide a valuable addition to Southern blotting or PCR methods for the accurate identification of genetic deletions in Becker muscular dystrophy patients. The antibodies were mapped to the following exons: exon 45 (2 mAbs), exon 46 (6), exon 47 (1), exons 47/48 (4), exons 48-50 (6), and exon 50 (1). PCR amplification of single exons or groups of exons was used both to produce specific dystrophin immunogens and to map the mAbs obtained. PCR-mediated mutagenesis was also used to identify regions of dystrophin important for mAb binding. Because the mAbs can be used to characterize the dystrophin produced by individual muscle fibres, they will also be useful for studying {open_quotes}revertant{close_quotes} fibres in Duchenne muscle and for monitoring the results of myoblast therapy trials in MD patients with deletions in this region of the dystrophin gene. 27 refs., 7 figs., 3 tabs.
Aircraft system modeling error and control error
NASA Technical Reports Server (NTRS)
Kulkarni, Nilesh V. (Inventor); Kaneshige, John T. (Inventor); Krishnakumar, Kalmanje S. (Inventor); Burken, John J. (Inventor)
A method for modeling error-driven adaptive control of an aircraft. Normal aircraft plant dynamics is modeled, using an original plant description in which a controller responds to a tracking error e(k) to drive the component to a normal reference value according to an asymptote curve. Where the system senses that (1) at least one aircraft plant component is experiencing an excursion and (2) the return of this component value toward its reference value is not proceeding according to the expected controller characteristics, neural network (NN) modeling of aircraft plant operation may be changed. However, if (1) is satisfied but the error component is returning toward its reference value according to expected controller characteristics, the NN will continue to model operation of the aircraft plant according to an original description.
Impaired Self-Monitoring of Inner Speech in Schizophrenia Patients with Verbal Hallucinations and in Non-clinical Individuals Prone to Hallucinations
Brébion, Gildas; Stephan-Otto, Christian; Ochoa, Susana; Roca, Mercedes; Nieto, Lourdes; Usall, Judith
Background: Previous research has shown that various memory errors reflecting failure in the self-monitoring of speech were associated with auditory/verbal hallucinations in schizophrenia patients and with proneness to hallucinations in non-clinical individuals. Method: We administered to 57 schizophrenia patients and 60 healthy participants a verbal memory task involving free recall and recognition of lists of words with different structures (high-frequency, low-frequency, and semantically organisable words). Extra-list intrusions in free recall were tallied, and the response bias reflecting tendency to make false recognitions of non-presented words was computed for each list. Results: In the male patient subsample, extra-list intrusions were positively associated with verbal hallucinations and inversely associated with negative symptoms. In the healthy participants the extra-list intrusions were positively associated with proneness to hallucinations. A liberal response bias in the recognition of the high-frequency words was associated with verbal hallucinations in male patients and with proneness to hallucinations in healthy men. Meanwhile, a conservative response bias for these high-frequency words was associated with negative symptoms in male patients and with social anhedonia in healthy men. Conclusion: Misattribution of inner speech to an external source, reflected by false recollection of familiar material, seems to underlie both clinical and non-clinical hallucinations. Further, both clinical and non-clinical negative symptoms may exert on verbal memory errors an effect opposite to that of hallucinations. PMID:27683568
Procrastination and suicide proneness: A moderated-mediation model for cognitive schemas and gender.
Klibert, Jeffrey; LeLeux-LaBarge, Kayla; Tarantino, Nicholas; Yancey, Thresa; Lamis, Dorian A
This study examined the direct and indirect paths between procrastination and suicide proneness while considering gender differences. Participants included 547 undergraduates from a southeastern university. Procrastination was positively related to suicide proneness for both genders, although this relation was stronger for women. Moderated-mediation analyses with bootstrapping highlighted insufficient self-control schemas as a mediator in the relation between procrastination and suicide proneness. However, indirect pathways did not vary by gender. Results represent an extension of the Procrastination-Health Model by highlighting the contribution of cognitive factors in explaining the relation between procrastination and suicide proneness.
The discovery of error-prone DNA polymerase V and its unique regulation by RecA and ATP.
Goodman, Myron F
My career pathway has taken a circuitous route, beginning with a Ph.D. degree in electrical engineering from The Johns Hopkins University, followed by five postdoctoral years in biology at Hopkins and culminating in a faculty position in biological sciences at the University of Southern California. My startup package in 1973 consisted of $2,500, not to be spent all at once, plus an ancient Packard scintillation counter that had a series of rapidly flashing light bulbs to indicate a radioactive readout in counts/minute. My research pathway has been similarly circuitous. The discovery of Escherichia coli DNA polymerase V (pol V) began with an attempt to identify the mutagenic DNA polymerase responsible for copying damaged DNA as part of the well known SOS regulon. Although we succeeded in identifying a DNA polymerase, one that was induced as part of the SOS response, we actually rediscovered DNA polymerase II, albeit in a new role. A decade later, we discovered a new polymerase, pol V, whose activity turned out to be regulated by bound molecules of RecA protein and ATP. This Reflections article describes our research trajectory, includes a review of key features of DNA damage-induced SOS mutagenesis leading us to pol V, and reflects on some of the principal researchers who have made indispensable contributions to our efforts.
The extent of error-prone replication restart by homologous recombination is controlled by Exo1 and checkpoint proteins.
Tsang, Ellen; Miyabe, Izumi; Iraqui, Ismail; Zheng, Jiping; Lambert, Sarah A E; Carr, Antony M
Genetic instability, a hallmark of cancer, can occur when the replication machinery encounters a barrier. The intra-S-phase checkpoint maintains stalled replication forks in a replication-competent configuration by phosphorylating replisome components and DNA repair proteins to prevent forks from catastrophically collapsing. Here, we report a novel function of the core Schizosaccharomyces pombe checkpoint sensor kinase, Rad3 (an ATR orthologue), that is independent of Chk1 and Cds1 (a CHK2 orthologue); Rad3(ATR) regulates the association of recombination factors with collapsed forks, thus limiting their genetic instability. We further reveal antagonistic roles for Rad3(ATR) and the 9-1-1 clamp - Rad3(ATR) restrains MRN- and Exo1-dependent resection, whereas the 9-1-1 complex promotes Exo1 activity. Interestingly, the MRN complex, but not its nuclease activity, promotes resection and the subsequent association of recombination factors at collapsed forks. The biological significance of this regulation is revealed by the observation that Rad3(ATR) prevents Exo1-dependent genome instability upstream of a collapsed fork without affecting the efficiency of recombination-mediated replication restart. We propose that the interplay between Rad3(ATR) and the 9-1-1 clamp functions to fine-tune the balance between the need for the recovery of replication through recombination and the risk of increased genome instability.
TRIP13 promotes error-prone nonhomologous end joining and induces chemoresistance in head and neck cancer
Banerjee, Rajat; Russo, Nickole; Liu, Min; Basrur, Venkatesha; Bellile, Emily; Palanisamy, Nallasivam; Scanlon, Christina S.; van Tubergen, Elizabeth; Inglehart, Ronald C.; Metwally, Tarek; Mani, Ram-Shankar; Yocum, Anastasia; Nyati, Mukesh K.; Castilho, Rogerio M.; Varambally, Sooryanarayana; Chinnaiyan, Arul M.
Head and neck cancer (SCCHN) is a common, aggressive, treatment-resistant cancer with a high recurrence rate and mortality, but the mechanism of treatment-resistance remains unclear. Here we describe a mechanism where the AAA-ATPase TRIP13 promotes treatment-resistance. Overexpression of TRIP13 in non-malignant cells results in malignant transformation. High expression of TRIP13 in SCCHN leads to aggressive, treatment-resistant tumors and enhanced repair of DNA damage. Using mass spectrometry, we identify DNA-PKcs complex proteins that mediate non homologous end joining (NHEJ), as TRIP13 binding partners. Using repair-deficient reporter systems, we show that TRIP13 promotes NHEJ, even when homologous recombination is intact. Importantly, overexpression of TRIP13 sensitizes SCCHN to an inhibitor of DNA-PKcs. Thus, this study defines a new mechanism of treatment resistance in SCCHN and underscores the importance of targeting NHEJ to overcome treatment failure in SCCHN and potentially in other cancers that overexpress TRIP13. PMID:25078033
Structural Dynamics as a Contributor to Error-prone Replication by an RNA-dependent RNA Polymerase*
Moustafa, Ibrahim M.; Korboukh, Victoria K.; Arnold, Jamie J.; Smidansky, Eric D.; Marcotte, Laura L.; Gohara, David W.; Yang, Xiaorong; Sánchez-Farrán, María Antonieta; Filman, David; Maranas, Janna K.; Boehr, David D.; Hogle, James M.; Colina, Coray M.; Cameron, Craig E.
RNA viruses encoding high- or low-fidelity RNA-dependent RNA polymerases (RdRp) are attenuated. The ability to predict residues of the RdRp required for faithful incorporation of nucleotides represents an essential step in any pipeline intended to exploit perturbed fidelity as the basis for rational design of vaccine candidates. We used x-ray crystallography, molecular dynamics simulations, NMR spectroscopy, and pre-steady-state kinetics to compare a mutator (H273R) RdRp from poliovirus to the wild-type (WT) enzyme. We show that the nucleotide-binding site toggles between the nucleotide binding-occluded and nucleotide binding-competent states. The conformational dynamics between these states were enhanced by binding to primed template RNA. For the WT, the occluded conformation was favored; for H273R, the competent conformation was favored. The resonance for Met-187 in our NMR spectra reported on the ability of the enzyme to check the correctness of the bound nucleotide. Kinetic experiments were consistent with the conformational dynamics contributing to the established pre-incorporation conformational change and fidelity checkpoint. For H273R, residues comprising the active site spent more time in the catalytically competent conformation and were more positively correlated than the WT. We propose that by linking the equilibrium between the binding-occluded and binding-competent conformations of the nucleotide-binding pocket and other active-site dynamics to the correctness of the bound nucleotide, faithful nucleotide incorporation is achieved. These studies underscore the need to apply multiple biophysical and biochemical approaches to the elucidation of the physical basis for polymerase fidelity. PMID:25378410
The Discovery of Error-prone DNA Polymerase V and Its Unique Regulation by RecA and ATP
Goodman, Myron F.
My career pathway has taken a circuitous route, beginning with a Ph.D. degree in electrical engineering from The Johns Hopkins University, followed by five postdoctoral years in biology at Hopkins and culminating in a faculty position in biological sciences at the University of Southern California. My startup package in 1973 consisted of $2,500, not to be spent all at once, plus an ancient Packard scintillation counter that had a series of rapidly flashing light bulbs to indicate a radioactive readout in counts/minute. My research pathway has been similarly circuitous. The discovery of Escherichia coli DNA polymerase V (pol V) began with an attempt to identify the mutagenic DNA polymerase responsible for copying damaged DNA as part of the well known SOS regulon. Although we succeeded in identifying a DNA polymerase, one that was induced as part of the SOS response, we actually rediscovered DNA polymerase II, albeit in a new role. A decade later, we discovered a new polymerase, pol V, whose activity turned out to be regulated by bound molecules of RecA protein and ATP. This Reflections article describes our research trajectory, includes a review of key features of DNA damage-induced SOS mutagenesis leading us to pol V, and reflects on some of the principal researchers who have made indispensable contributions to our efforts. PMID:25160630
Automated Forensic Animal Family Identification by Nested PCR and Melt Curve Analysis on an Off-the-Shelf Thermocycler Augmented with a Centrifugal Microfluidic Disk Segment
Zengerle, Roland; von Stetten, Felix; Schmidt, Ulrike
Nested PCR remains a labor-intensive and error-prone biomolecular analysis. Laboratory workflow automation by precise control of minute liquid volumes in centrifugal microfluidic Lab-on-a-Chip systems holds great potential for such applications. However, the majority of these systems require costly custom-made processing devices. Our idea is to augment a standard laboratory device, here a centrifugal real-time PCR thermocycler, with inbuilt liquid handling capabilities for automation. We have developed a microfluidic disk segment enabling an automated nested real-time PCR assay for identification of common European animal groups adapted to forensic standards. For the first time we utilize a novel combination of fluidic elements, including pre-storage of reagents, to automate the assay at constant rotational frequency of an off-the-shelf thermocycler. It provides a universal duplex pre-amplification of short fragments of the mitochondrial 12S rRNA and cytochrome b genes, animal-group-specific main-amplifications, and melting curve analysis for differentiation. The system was characterized with respect to assay sensitivity, specificity, risk of cross-contamination, and detection of minor components in mixtures. 92.2% of the performed tests were recognized as fluidically failure-free sample handling and used for evaluation. Altogether, augmentation of the standard real-time thermocycler with a self-contained centrifugal microfluidic disk segment resulted in an accelerated and automated analysis reducing hands-on time, and circumventing the risk of contamination associated with regular nested PCR protocols. PMID:26147196
Quantitative Expression Analysis in Brassica napus by Northern Blot Analysis and Reverse Transcription-Quantitative PCR in a Complex Experimental Setting
Rumlow, Annekathrin; Keunen, Els; Klein, Jan; Pallmann, Philip; Riemenschneider, Anja; Cuypers, Ann
Analysis of gene expression is one of the major ways to better understand plant reactions to changes in environmental conditions. The comparison of many different factors influencing plant growth challenges the gene expression analysis for specific gene-targeted experiments, especially with regard to the choice of suitable reference genes. The aim of this study is to compare expression results obtained by Northern blot, semi-quantitative PCR and RT-qPCR, and to identify a reliable set of reference genes for oilseed rape (Brassica napus L.) suitable for comparing gene expression under complex experimental conditions. We investigated the influence of several factors such as sulfur deficiency, different time points during the day, varying light conditions, and their interaction on gene expression in oilseed rape plants. The expression of selected reference genes was indeed influenced under these conditions in different ways. Therefore, a recently developed algorithm, called GrayNorm, was applied to validate a set of reference genes for normalizing results obtained by Northern blot analysis. After careful comparison of the three methods mentioned above, Northern blot analysis seems to be a reliable and cost-effective alternative for gene expression analysis under a complex growth regime. For using this method in a quantitative way a number of references was validated revealing that for our experiment a set of three references provides an appropriate normalization. Semi-quantitative PCR was prone to many handling errors and difficult to control while RT-qPCR was very sensitive to expression fluctuations of the reference genes. PMID:27685087
Olson, Eric J.
An apparatus, program product, and method that run an algorithm on a hardware based processor, generate a hardware error as a result of running the algorithm, generate an algorithm output for the algorithm, compare the algorithm output to another output for the algorithm, and detect the hardware error from the comparison. The algorithm is designed to cause the hardware based processor to heat to a degree that increases the likelihood of hardware errors to manifest, and the hardware error is observable in the algorithm output. As such, electronic components may be sufficiently heated and/or sufficiently stressed to create better conditions for generating hardware errors, and the output of the algorithm may be compared at the end of the run to detect a hardware error that occurred anywhere during the run that may otherwise not be detected by traditional methodologies (e.g., due to cooling, insufficient heat and/or stress, etc.).
NASA Technical Reports Server (NTRS)
Buechler, W.; Tucker, A. G.
Several methods were employed to detect both the occurrence and source of errors in the operational software of the AN/SLQ-32. A large embedded real time electronic warfare command and control system for the ROLM 1606 computer are presented. The ROLM computer provides information about invalid addressing, improper use of privileged instructions, stack overflows, and unimplemented instructions. Additionally, software techniques were developed to detect invalid jumps, indices out of range, infinte loops, stack underflows, and field size errors. Finally, data are saved to provide information about the status of the system when an error is detected. This information includes I/O buffers, interrupt counts, stack contents, and recently passed locations. The various errors detected, techniques to assist in debugging problems, and segment simulation on a nontarget computer are discussed. These error detection techniques were a major factor in the success of finding the primary cause of error in 98% of over 500 system dumps.
Measurement Error Adjustment Using the SIMEX Method: An Application to Student Growth Percentiles
ERIC Educational Resources Information Center
Shang, Yi
Growth models are used extensively in the context of educational accountability to evaluate student-, class-, and school-level growth. However, when error-prone test scores are used as independent variables or right-hand-side controls, the estimation of such growth models can be substantially biased. This article introduces a…
Predicting First Grade Achievement from Form Errors in Printing at the Start of Pre-Kindergarten.
ERIC Educational Resources Information Center
Simner, Marvin L.
A 3-year longitudinal investigation indicated that form errors in printing that children make can aid in the identification of at-risk or failure-prone pupils as early as the start of prekindergarten. Two samples were selected, one consisting of 104 and the other of 63 prekindergarten children. Mean age of the samples was 52 months. Item analysis…
NASA Technical Reports Server (NTRS)
Briggs, Hugh C.
An error budget is a commonly used tool in design of complex aerospace systems. It represents system performance requirements in terms of allowable errors and flows these down through a hierarchical structure to lower assemblies and components. The requirements may simply be 'allocated' based upon heuristics or experience, or they may be designed through use of physics-based models. This paper presents a basis for developing an error budget for models of the system, as opposed to the system itself. The need for model error budgets arises when system models are a principle design agent as is increasingly more common for poorly testable high performance space systems.
NASA Technical Reports Server (NTRS)
Noble, Viveca K.
There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.
The U.S. Environmental Protection Agency (EPA) held a workshop in January 2003 on the detection of viruses in water using polymerase chain reaction (PCR)-based methods. Speakers were asked to address a series of specific questions, including whether a single standard method coul...
The purpose of this presentation is to present an overview of the quality control (QC) sections of a draft EPA document entitled, "Quality Assurance/Quality Control Guidance for Laboratories Performing PCR Analyses on Environmental Samples." This document has been prepared by th...
SU-F-BRB-02: Towards Quantitative Clinical Decision On Deep Inspiration Breath Hold (DIBH) Or Prone for Left-Sided Breast Irradiation
Lin, H; Gao, Y; Liu, T; Gelblum, D; Ho, A; Powell, S; Tang, X; Xu, X
Purpose: To develop quantitative clinical guidelines between supine Deep Inspiratory Breath Hold (DIBH) and prone free breathing treatments for breast patients, we applied 3D deformable phantoms to perform Monte Carlo simulation to predict corresponding Dose to the Organs at Risk (OARs). Methods: The RPI-adult female phantom (two selected cup sizes: A and D) was used to represent the female patient, and it was simulated using the MCNP6 Monte Carlo code. Doses to OARs were investigated for supine DIBH and prone treatments, considering two breast sizes. The fluence maps of the 6-MV opposed tangential fields were exported. In the Monte Carlo simulation, the fluence maps allow each simulated photon particle to be weighed in the final dose calculation. The relative error of all dose calculations was kept below 5% by simulating 3*10{sup 7} photons for each projection. Results: In terms of dosimetric accuracy, the RPI Adult Female phantom with cup size D in DIBH positioning matched with a DIBH treatment plan of the patient. Based on the simulation results, for cup size D phantom, prone positioning reduced the cardiac dose and the dose to other OARs, while cup size A phantom benefits more from DIBH positioning. Comparing simulation results for cup size A and D phantom, dose to OARs was generally higher for the large breast size due to increased scattering arising from a larger portion of the body in the primary beam. The lower dose that was registered for the heart in the large breast phantom in prone positioning was due to the increase of the distance between the heart and the primary beam when the breast was pendulous. Conclusion: Our 3D deformable phantom appears an excellent tool to predict dose to the OARs for the supine DIBH and prone positions, which might help quantitative clinical decisions. Further investigation will be conducted. National Institutes of Health R01EB015478.
Pathogenesis of A−β+ Ketosis-Prone Diabetes
Patel, Sanjeet G.; Hsu, Jean W.; Jahoor, Farook; Coraza, Ivonne; Bain, James R.; Stevens, Robert D.; Iyer, Dinakar; Nalini, Ramaswami; Ozer, Kerem; Hampe, Christiane S.; Newgard, Christopher B.; Balasubramanyam, Ashok
A−β+ ketosis-prone diabetes (KPD) is an emerging syndrome of obesity, unprovoked ketoacidosis, reversible β-cell dysfunction, and near-normoglycemic remission. We combined metabolomics with targeted kinetic measurements to investigate its pathophysiology. Fasting plasma fatty acids, acylcarnitines, and amino acids were quantified in 20 KPD patients compared with 19 nondiabetic control subjects. Unique signatures in KPD—higher glutamate but lower glutamine and citrulline concentrations, increased β-hydroxybutyryl-carnitine, decreased isovaleryl-carnitine (a leucine catabolite), and decreased tricarboxylic acid (TCA) cycle intermediates—generated hypotheses that were tested through stable isotope/mass spectrometry protocols in nine new-onset, stable KPD patients compared with seven nondiabetic control subjects. Free fatty acid flux and acetyl CoA flux and oxidation were similar, but KPD had slower acetyl CoA conversion to β-hydroxybutyrate; higher fasting β-hydroxybutyrate concentration; slower β-hydroxybutyrate oxidation; faster leucine oxidative decarboxylation; accelerated glutamine conversion to glutamate without increase in glutamate carbon oxidation; and slower citrulline flux, with diminished glutamine amide–nitrogen transfer to citrulline. The confluence of metabolomic and kinetic data indicate a distinctive pathogenic sequence: impaired ketone oxidation and fatty acid utilization for energy, leading to accelerated leucine catabolism and transamination of α-ketoglutarate to glutamate, with impaired TCA anaplerosis of glutamate carbon. They highlight a novel process of defective energy production and ketosis in A−β+ KPD. PMID:23160531
Multidisciplinary approach to converting power chair into motorized prone cart.
Brose, Steven W; Wali, Eisha
Pressure ulcers remain a major source of morbidity and mortality in veterans with neurologic impairment. Management of pressure ulcers typically involves pressure relief over skin regions containing wounds, but this can lead to loss of mobility and independence when the wounds are located in regions that receive pressure from sitting. An innovative, low-cost, multidisciplinary effort was undertaken to maximize quality of life in a veteran with a thoracic-4 level complete spinal cord injury and a stage 4 ischial wound. The person's power wheelchair was converted into a motorized prone cart, allowing navigation of the Department of Veterans Affairs spinal cord injury hospital ward and improved socialization while relieving pressure on the wound. Physical and occupational therapy assisted with the reconfiguration of the power chair and verified safe transfers into the chair and driving of the device. Psychology verified positive psychosocial benefit, while nursing and physician services verified an absence of unwanted pain or skin injury resulting from use of the device. Further investigation of ways to apply this technique is warranted to improve the quality of life of persons with pressure ulcers.
Arthroscopic subtalar arthrodesis: the posterior approach in the prone position.
Carro, Luis Perez; Golanó, Pau; Vega, Jordi
Arthroscopic subtalar arthrodesis, as reported by Tasto, is done in the lateral decubitus position, and the portal sites are lateral. This report describes a new alternative method in which the patient is in the prone position and a posterior 2-portal approach is used, as described by van Dijk et al. The initial debridement and synovectomy are performed with 4- and 5-mm resectors. Debridement and decortication are done posterior to the interosseous ligament because only the posterior facet is fused. Denudation of the articular surfaces is performed with curettes, as well as 4.5- and 5.5-mm burs, to remove 2 mm of subchondral bone. Stabilization in 5 degrees of hindfoot valgus is accomplished with 2 percutaneous cannulated headless screws from the non-weight-bearing portion of the calcaneal tuberosity directed to a point 5 to 10 mm posterior to the anterior margin of the posterior facet. The advantages of this alternative treatment are better intra-articular visualization, more thorough preparation of the fusion site, and minimal bone removal of the lateral side with better control of the arthrodesis position and with less chance of malunion, as well as the possibility to perform a concomitant surgical fusion or debridement of the ankle joint during the same operative procedure with no need for additional portals or orientation.
Development of Korean Smartphone Addiction Proneness Scale for Youth
Kim, Dongil; Lee, Yunhee; Lee, Juyoung; Nam, JeeEun Karin; Chung, Yeoju
This study developed a Smartphone Addiction Proneness Scale (SAPS) based on the existing internet and cellular phone addiction scales. For the development of this scale, 29 items (1.5 times the final number of items) were initially selected as preliminary items, based on the previous studies on internet/phone addiction as well as the clinical experience of involved experts. The preliminary scale was administered to a nationally representative sample of 795 students in elementary, middle, and high schools across South Korea. Then, final 15 items were selected according to the reliability test results. The final scale consisted of four subdomains: (1) disturbance of adaptive functions, (2) virtual life orientation, (3) withdrawal, and (4) tolerance. The final scale indicated a high reliability with Cronbach's α of .880. Support for the scale's criterion validity has been demonstrated by its relationship to the internet addiction scale, KS-II (r = .49). For the analysis of construct validity, we tested the Structural Equation Model. The results showed the four-factor structure to be valid (NFI = .943, TLI = .902, CFI = .902, RMSEA = .034). Smartphone addiction is gaining a greater spotlight as possibly a new form of addiction along with internet addiction. The SAPS appears to be a reliable and valid diagnostic scale for screening adolescents who may be at risk of smartphone addiction. Further implications and limitations are discussed. PMID:24848006
Signature of an aggregation-prone conformation of tau
NASA Astrophysics Data System (ADS)
Eschmann, Neil A.; Georgieva, Elka R.; Ganguly, Pritam; Borbat, Peter P.; Rappaport, Maxime D.; Akdogan, Yasar; Freed, Jack H.; Shea, Joan-Emma; Han, Songi
The self-assembly of the microtubule associated tau protein into fibrillar cell inclusions is linked to a number of devastating neurodegenerative disorders collectively known as tauopathies. The mechanism by which tau self-assembles into pathological entities is a matter of much debate, largely due to the lack of direct experimental insights into the earliest stages of aggregation. We present pulsed double electron-electron resonance measurements of two key fibril-forming regions of tau, PHF6 and PHF6*, in transient as aggregation happens. By monitoring the end-to-end distance distribution of these segments as a function of aggregation time, we show that the PHF6(*) regions dramatically extend to distances commensurate with extended β-strand structures within the earliest stages of aggregation, well before fibril formation. Combined with simulations, our experiments show that the extended β-strand conformational state of PHF6(*) is readily populated under aggregating conditions, constituting a defining signature of aggregation-prone tau, and as such, a possible target for therapeutic interventions.
Development of Korean Smartphone addiction proneness scale for youth.
Kim, Dongil; Lee, Yunhee; Lee, Juyoung; Nam, JeeEun Karin; Chung, Yeoju
This study developed a Smartphone Addiction Proneness Scale (SAPS) based on the existing internet and cellular phone addiction scales. For the development of this scale, 29 items (1.5 times the final number of items) were initially selected as preliminary items, based on the previous studies on internet/phone addiction as well as the clinical experience of involved experts. The preliminary scale was administered to a nationally representative sample of 795 students in elementary, middle, and high schools across South Korea. Then, final 15 items were selected according to the reliability test results. The final scale consisted of four subdomains: (1) disturbance of adaptive functions, (2) virtual life orientation, (3) withdrawal, and (4) tolerance. The final scale indicated a high reliability with Cronbach's α of .880. Support for the scale's criterion validity has been demonstrated by its relationship to the internet addiction scale, KS-II (r = .49). For the analysis of construct validity, we tested the Structural Equation Model. The results showed the four-factor structure to be valid (NFI = .943, TLI = .902, CFI = .902, RMSEA = .034). Smartphone addiction is gaining a greater spotlight as possibly a new form of addiction along with internet addiction. The SAPS appears to be a reliable and valid diagnostic scale for screening adolescents who may be at risk of smartphone addiction. Further implications and limitations are discussed.
Signature of an aggregation-prone conformation of tau
Eschmann, Neil A.; Georgieva, Elka R.; Ganguly, Pritam; Borbat, Peter P.; Rappaport, Maxime D.; Akdogan, Yasar; Freed, Jack H.; Shea, Joan-Emma; Han, Songi
The self-assembly of the microtubule associated tau protein into fibrillar cell inclusions is linked to a number of devastating neurodegenerative disorders collectively known as tauopathies. The mechanism by which tau self-assembles into pathological entities is a matter of much debate, largely due to the lack of direct experimental insights into the earliest stages of aggregation. We present pulsed double electron-electron resonance measurements of two key fibril-forming regions of tau, PHF6 and PHF6*, in transient as aggregation happens. By monitoring the end-to-end distance distribution of these segments as a function of aggregation time, we show that the PHF6(*) regions dramatically extend to distances commensurate with extended β-strand structures within the earliest stages of aggregation, well before fibril formation. Combined with simulations, our experiments show that the extended β-strand conformational state of PHF6(*) is readily populated under aggregating conditions, constituting a defining signature of aggregation-prone tau, and as such, a possible target for therapeutic interventions. PMID:28303942
Twenty Questions about Student Errors.
ERIC Educational Resources Information Center
Fisher, Kathleen M.; Lipson, Joseph Isaac
Discusses the value of studying errors made by students in the process of learning science. Addresses 20 research questions dealing with student learning errors. Attempts to characterize errors made by students and clarify some terms used in error research. (TW)
Action errors, error management, and learning in organizations.
Frese, Michael; Keith, Nina
Every organization is confronted with errors. Most errors are corrected easily, but some may lead to negative consequences. Organizations often focus on error prevention as a single strategy for dealing with errors. Our review suggests that error prevention needs to be supplemented by error management--an approach directed at effectively dealing with errors after they have occurred, with the goal of minimizing negative and maximizing positive error consequences (examples of the latter are learning and innovations). After defining errors and related concepts, we review research on error-related processes affected by error management (error detection, damage control). Empirical evidence on positive effects of error management in individuals and organizations is then discussed, along with emotional, motivational, cognitive, and behavioral pathways of these effects. Learning from errors is central, but like other positive consequences, learning occurs under certain circumstances--one being the development of a mind-set of acceptance of human error.
Dandona, R.; Dandona, L.
Recent data suggest that a large number of people are blind in different parts of the world due to high refractive error because they are not using appropriate refractive correction. Refractive error as a cause of blindness has been recognized only recently with the increasing use of presenting visual acuity for defining blindness. In addition to blindness due to naturally occurring high refractive error, inadequate refractive correction of aphakia after cataract surgery is also a significant cause of blindness in developing countries. Blindness due to refractive error in any population suggests that eye care services in general in that population are inadequate since treatment of refractive error is perhaps the simplest and most effective form of eye care. Strategies such as vision screening programmes need to be implemented on a large scale to detect individuals suffering from refractive error blindness. Sufficient numbers of personnel to perform reasonable quality refraction need to be trained in developing countries. Also adequate infrastructure has to be developed in underserved areas of the world to facilitate the logistics of providing affordable reasonable-quality spectacles to individuals suffering from refractive error blindness. Long-term success in reducing refractive error blindness worldwide will require attention to these issues within the context of comprehensive approaches to reduce all causes of avoidable blindness. PMID:11285669
ERIC Educational Resources Information Center
Richmond, Kent C.
Students of English as a second language (ESL) often come to the classroom with little or no experience in writing in any language and with inaccurate assumptions about writing. Rather than correct these assumptions, teachers often seem to unwittingly reinforce them, actually inducing errors into their students' work. Teacher-induced errors occur…
Use of Droplet Digital PCR for Estimation of Fish Abundance and Biomass in Environmental DNA Surveys
Doi, Hideyuki; Uchii, Kimiko; Takahara, Teruhiko; Matsuhashi, Saeko; Yamanaka, Hiroki; Minamoto, Toshifumi
An environmental DNA (eDNA) analysis method has been recently developed to estimate the distribution of aquatic animals by quantifying the number of target DNA copies with quantitative real-time PCR (qPCR). A new quantitative PCR technology, droplet digital PCR (ddPCR), partitions PCR reactions into thousands of droplets and detects the amplification in each droplet, thereby allowing direct quantification of target DNA. We evaluated the quantification accuracy of qPCR and ddPCR to estimate species abundance and biomass by using eDNA in mesocosm experiments involving different numbers of common carp. We found that ddPCR quantified the concentration of carp eDNA along with carp abundance and biomass more accurately than qPCR, especially at low eDNA concentrations. In addition, errors in the analysis were smaller in ddPCR than in qPCR. Thus, ddPCR is better suited to measure eDNA concentration in water, and it provides more accurate results for the abundance and biomass of the target species than qPCR. We also found that the relationship between carp abundance and eDNA concentration was stronger than that between biomass and eDNA by using both ddPCR and qPCR; this suggests that abundance can be better estimated by the analysis of eDNA for species with fewer variations in body mass. PMID:25799582
44 CFR 60.22 - Planning considerations for flood-prone areas.
Code of Federal Regulations, 2013 CFR
... flood-prone areas. 60.22 Section 60.22 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing Flood-Prone, Mudslide...
44 CFR 60.22 - Planning considerations for flood-prone areas.
Code of Federal Regulations, 2012 CFR
... flood-prone areas. 60.22 Section 60.22 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing Flood-Prone, Mudslide...
44 CFR 60.22 - Planning considerations for flood-prone areas.
Code of Federal Regulations, 2011 CFR
... flood-prone areas. 60.22 Section 60.22 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing Flood-Prone, Mudslide...
44 CFR 60.22 - Planning considerations for flood-prone areas.
Code of Federal Regulations, 2014 CFR
... flood-prone areas. 60.22 Section 60.22 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing Flood-Prone, Mudslide...
Critical Differences between the Type-A Prone and Type-A Personalitites.
ERIC Educational Resources Information Center
Cassel, Russell N.; Cassel, Susie L.
Type-A Prone and Type-A personalities were assessed on the basis of the Cassel Type-A Personality Assessment Profile. Statistical data analysis indicated differences in positive lifestyle, blood pressure, and self-control and no differences in negative lifestyle, pulse rate, or peripheral temperature. Type-A Prone and Type-A norm profiles were…
Suicide Proneness in College Students: Relationships with Gender, Procrastination, and Achievement Motivation
ERIC Educational Resources Information Center
Klibert, Jeffrey; Langhinrichsen-Rohling, Jennifer; Luna, Amy; Robichaux, Michelle
This study examined the relationships between 2 academic dispositions (i.e., procrastination and achievement motivation) and 2 indices of suicidal proneness in college women and men. The degree these 2 academic dispositions could predict unique variance in suicide proneness scores, above and beyond the influence of depression and self-esteem was…
44 CFR 60.23 - Planning considerations for mudslide (i.e., mudflow)-prone areas.
Code of Federal Regulations, 2013 CFR
..., Mudslide (i.e., Mudflow)-Prone and Flood-Related Erosion-Prone Areas § 60.23 Planning considerations for... location of public utilities and service facilities, such as sewer, water, gas and electrical systems and..., flood plain, mudslide (i.e., mudflow), soil, land, and water regulation in neighboring communities;...
The Relationship of Stress Arousal and Stress Prone Personality Traits to Menstrual Distress.
ERIC Educational Resources Information Center
Marini, David C.
The various relationships of stress arousal and stress-prone personality traits to menstrual distress were investigated in order to quantify psychophysiological arousal differences between high and low menstrual distress symptom reporters and examine differences in stress-prone personality traits between high and low menstrual distress symptom…
NASA Astrophysics Data System (ADS)
Braun, Dieter
The Polymerase Chain Reaction (PCR) allows for highly sensitive and specific amplification of DNA. It is the backbone of many genetic experiments and tests. Recently, three labs independently uncovered a novel and simple way to perform a PCR reaction. Instead of repetitive heating and cooling, a temperature gradient across the reaction vessel drives thermal convection. By convection, the reaction liquid circulates between hot and cold regions of the chamber. The convection triggers DNA amplification as the DNA melts into two single strands in the hot region and replicates into twice the amount in the cold region. The amplification progresses exponentially as the convection moves on. We review the characteristics of the different approaches and show the benefits and prospects of the method.
Morling, Niels
Since the introduction in the mid-1980s of analyses of minisatellites for DNA analyses, a revolution has taken place in forensic genetics. The subsequent invention of the PCR made it possible to develop forensic genetics tools that allow both very informative routine investigations and still more and more advanced, special investigations in cases concerning crime, paternity, relationship, disaster victim identification etc. The present review gives an update on the use of DNA investigations in forensic genetics.
Preliminary Results on Setup Precision of Prone-Lateral Patient Positioning for Whole Breast Irradiation
Veldeman, Liv; Speleers, Bruno; Bakker, Marlies; Jacobs, Filip; Coghe, Marc; De Gersem, Werner; Impens, Aline; Nechelput, Sarah; De Wagter, Carlos
Purpose: The aim of this study was to develop a rapid and reproducible technique for prone positioning and to compare dose-volume indices in prone and supine positions. Methods and Materials: Eighteen patients underwent computed tomography imaging for radiotherapy planning in prone and supine position. Experience was gained in the first eight patients, which lead to modifications of the Horizon prone breast board (Civco Medical Solutions, Orange City, Iowa, USA) and the patient setup technique. A unilateral breast holder (U-BH) was developed (Van de Velde, Schellebelle, Belgium) to retract the contralateral breast away from the treated breast. The technique was then applied to an additional 10 patients. The setup precision was evaluated using daily cone-beam CT. Results: Modifications to the breast board were made to secure a prone-lateral rather then a pure prone position. We evolved from a classical setup using laser marks on the patients' body to a direct breast setup using marks on the breast only. The setup precision of the direct positioning procedure with the modified breast board and the U-BH is comparable to supine setup data in the literature. Dose-volume indices for heart and lung show significantly better results for prone than for supine position, and dose homogeneity within the treated breast did not differ according to the treatment position. Conclusions: The setup precision of our prone-lateral positioning technique is comparable to supine data in literature. Our data show the advantage of prone radiotherapy to spare the lung and heart. Further research is necessary to reduce the duration of prone setup.
Uncorrected refractive errors.
Naidoo, Kovin S; Jaggernath, Jyoti
Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC), were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR) Development, Service Development and Social Entrepreneurship.
Medication Errors in Cardiopulmonary Arrest and Code-Related Situations.
Flannery, Alexander H; Parli, Sara E
PubMed/MEDLINE (1966-November 2014) was searched to identify relevant published studies on the overall frequency, types, and examples of medication errors during medical emergencies involving cardiopulmonary resuscitation and related situations, and the breakdown by type of error. The overall frequency of medication errors during medical emergencies, specifically situations related to resuscitation, is highly variable. Medication errors during such emergencies, particularly cardiopulmonary resuscitation and surrounding events, are not well characterized in the literature but may be more frequent than previously thought. Depending on whether research methods included database mining, simulation, or prospective observation of clinical practice, reported occurrence of medication errors during cardiopulmonary resuscitation and surrounding events has ranged from less than 1% to 50%. Because of the chaos of the resuscitation environment, errors in prescribing, dosing, preparing, labeling, and administering drugs are prone to occur. System-based strategies, such as infusion pump policies and code cart management, as well as personal strategies exist to minimize medication errors during emergency situations.
NASA Technical Reports Server (NTRS)
In a complex computer environment there is ample opportunity for error, a mistake by a programmer, or a software-induced undesirable side effect. In insurance, errors can cost a company heavily, so protection against inadvertent change is a must for the efficient firm. The data processing center at Transport Life Insurance Company has taken a step to guard against accidental changes by adopting a software package called EQNINT (Equations Interpreter Program). EQNINT cross checks the basic formulas in a program against the formulas that make up the major production system. EQNINT assures that formulas are coded correctly and helps catch errors before they affect the customer service or its profitability.
Estimating Bias Error Distributions
NASA Technical Reports Server (NTRS)
Liu, Tian-Shu; Finley, Tom D.
This paper formulates the general methodology for estimating the bias error distribution of a device in a measuring domain from less accurate measurements when a minimal number of standard values (typically two values) are available. A new perspective is that the bias error distribution can be found as a solution of an intrinsic functional equation in a domain. Based on this theory, the scaling- and translation-based methods for determining the bias error distribution arc developed. These methods are virtually applicable to any device as long as the bias error distribution of the device can be sufficiently described by a power series (a polynomial) or a Fourier series in a domain. These methods have been validated through computational simulations and laboratory calibration experiments for a number of different devices.
Klonoff, David C; Lias, Courtney; Vigersky, Robert; Clarke, William; Parkes, Joan Lee; Sacks, David B; Kirkman, M Sue; Kovatchev, Boris
Currently used error grids for assessing clinical accuracy of blood glucose monitors are based on out-of-date medical practices. Error grids have not been widely embraced by regulatory agencies for clearance of monitors, but this type of tool could be useful for surveillance of the performance of cleared products. Diabetes Technology Society together with representatives from the Food and Drug Administration, the American Diabetes Association, the Endocrine Society, and the Association for the Advancement of Medical Instrumentation, and representatives of academia, industry, and government, have developed a new error grid, called the surveillance error grid (SEG) as a tool to assess the degree of clinical risk from inaccurate blood glucose (BG) monitors. A total of 206 diabetes clinicians were surveyed about the clinical risk of errors of measured BG levels by a monitor. The impact of such errors on 4 patient scenarios was surveyed. Each monitor/reference data pair was scored and color-coded on a graph per its average risk rating. Using modeled data representative of the accuracy of contemporary meters, the relationships between clinical risk and monitor error were calculated for the Clarke error grid (CEG), Parkes error grid (PEG), and SEG. SEG action boundaries were consistent across scenarios, regardless of whether the patient was type 1 or type 2 or using insulin or not. No significant differences were noted between responses of adult/pediatric or 4 types of clinicians. Although small specific differences in risk boundaries between US and non-US clinicians were noted, the panel felt they did not justify separate grids for these 2 types of clinicians. The data points of the SEG were classified in 15 zones according to their assigned level of risk, which allowed for comparisons with the classic CEG and PEG. Modeled glucose monitor data with realistic self-monitoring of blood glucose errors derived from meter testing experiments plotted on the SEG when compared to
NASA Astrophysics Data System (ADS)
Lidar, Daniel A.; Brun, Todd A.
Prologue; Preface; Part I. Background: 1. Introduction to decoherence and noise in open quantum systems Daniel Lidar and Todd Brun; 2. Introduction to quantum error correction Dave Bacon; 3. Introduction to decoherence-free subspaces and noiseless subsystems Daniel Lidar; 4. Introduction to quantum dynamical decoupling Lorenza Viola; 5. Introduction to quantum fault tolerance Panos Aliferis; Part II. Generalized Approaches to Quantum Error Correction: 6. Operator quantum error correction David Kribs and David Poulin; 7. Entanglement-assisted quantum error-correcting codes Todd Brun and Min-Hsiu Hsieh; 8. Continuous-time quantum error correction Ognyan Oreshkov; Part III. Advanced Quantum Codes: 9. Quantum convolutional codes Mark Wilde; 10. Non-additive quantum codes Markus Grassl and Martin Rötteler; 11. Iterative quantum coding systems David Poulin; 12. Algebraic quantum coding theory Andreas Klappenecker; 13. Optimization-based quantum error correction Andrew Fletcher; Part IV. Advanced Dynamical Decoupling: 14. High order dynamical decoupling Zhen-Yu Wang and Ren-Bao Liu; 15. Combinatorial approaches to dynamical decoupling Martin Rötteler and Pawel Wocjan; Part V. Alternative Quantum Computation Approaches: 16. Holonomic quantum computation Paolo Zanardi; 17. Fault tolerance for holonomic quantum computation Ognyan Oreshkov, Todd Brun and Daniel Lidar; 18. Fault tolerant measurement-based quantum computing Debbie Leung; Part VI. Topological Methods: 19. Topological codes Héctor Bombín; 20. Fault tolerant topological cluster state quantum computing Austin Fowler and Kovid Goyal; Part VII. Applications and Implementations: 21. Experimental quantum error correction Dave Bacon; 22. Experimental dynamical decoupling Lorenza Viola; 23. Architectures Jacob Taylor; 24. Error correction in quantum communication Mark Wilde; Part VIII. Critical Evaluation of Fault Tolerance: 25. Hamiltonian methods in QEC and fault tolerance Eduardo Novais, Eduardo Mucciolo and
Absolute reliability of isokinetic knee flexion and extension measurements adopting a prone position.
Ayala, F; De Ste Croix, M; Sainz de Baranda, P; Santonja, F
The main purpose of this study was to determine the absolute and relative reliability of isokinetic peak torque (PT), angle of peak torque (APT), average power (PW) and total work (TW) for knee flexion and extension during concentric and eccentric actions measured in a prone position at 60, 180 and 240° s(-1). A total of 50 recreational athletes completed the study. PT, APT, PW and TW for concentric and eccentric knee extension and flexion were recorded at three different angular velocities (60, 180 and 240° s(-1)) on three different occasions with a 72- to 96-h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CV(TE)), percentage change in the mean (ChM) and relative reliability with intraclass correlations (ICC(3,1)). For both the knee extensor and flexor muscle groups, all strength data (except APT during knee flexion movements) demonstrated moderate absolute reliability (ChM < 3%; ICCs > 0·70; and CV(TE) < 20%) independent of the knee movement (flexion and extension), type of muscle action (concentric and eccentric) and angular velocity (60, 180 and 240° s(-1)). Therefore, the current study suggests that the CV(TE) values reported for PT (8-20%), APT (8-18%) (only during knee extension movements), PW (14-20%) and TW (12-28%) may be acceptable to detect the large changes usually observed after rehabilitation programmes, but not acceptable to examine the effect of preventative training programmes in healthy individuals.
NASA Astrophysics Data System (ADS)
von Clarmann, T.
The difference due to the content of a priori information between a constrained retrieval and the true atmospheric state is usually represented by the so-called smoothing error. In this paper it is shown that the concept of the smoothing error is questionable because it is not compliant with Gaussian error propagation. The reason for this is that the smoothing error does not represent the expected deviation of the retrieval from the true state but the expected deviation of the retrieval from the atmospheric state sampled on an arbitrary grid, which is itself a smoothed representation of the true state. The idea of a sufficiently fine sampling of this reference atmospheric state is untenable because atmospheric variability occurs on all scales, implying that there is no limit beyond which the sampling is fine enough. Even the idealization of infinitesimally fine sampling of the reference state does not help because the smoothing error is applied to quantities which are only defined in a statistical sense, which implies that a finite volume of sufficient spatial extent is needed to meaningfully talk about temperature or concentration. Smoothing differences, however, which play a role when measurements are compared, are still a useful quantity if the involved a priori covariance matrix has been evaluated on the comparison grid rather than resulting from interpolation. This is, because the undefined component of the smoothing error, which is the effect of smoothing implied by the finite grid on which the measurements are compared, cancels out when the difference is calculated.
Thermodynamics of Error Correction
NASA Astrophysics Data System (ADS)
Sartori, Pablo; Pigolotti, Simone
Information processing at the molecular scale is limited by thermal fluctuations. This can cause undesired consequences in copying information since thermal noise can lead to errors that can compromise the functionality of the copy. For example, a high error rate during DNA duplication can lead to cell death. Given the importance of accurate copying at the molecular scale, it is fundamental to understand its thermodynamic features. In this paper, we derive a universal expression for the copy error as a function of entropy production and work dissipated by the system during wrong incorporations. Its derivation is based on the second law of thermodynamics; hence, its validity is independent of the details of the molecular machinery, be it any polymerase or artificial copying device. Using this expression, we find that information can be copied in three different regimes. In two of them, work is dissipated to either increase or decrease the error. In the third regime, the protocol extracts work while correcting errors, reminiscent of a Maxwell demon. As a case study, we apply our framework to study a copy protocol assisted by kinetic proofreading, and show that it can operate in any of these three regimes. We finally show that, for any effective proofreading scheme, error reduction is limited by the chemical driving of the proofreading reaction.
Modeling fluxes and form in landslide-prone terrain
NASA Astrophysics Data System (ADS)
Roering, J. J.; Booth, A. M.; Stock, J. D.
Landslides dramatically alter the Earth's surface over short timescales. The mass transfer associated with a limited number of slope failures can dominate the sediment budget of a region for decades or longer. The initiation, failure geometry, and runout of individual landslides depend on a range of factors and cannot be predicted from current models. Given these realities of landslide behavior over human timescales, it is challenging to reasonably represent these processes in landscape evolution models. Here, we evaluate the ability of two landslide models, both of which are formulated to apply at geomorphic timescales, to generate topographic patterns and sediment flux rates observed in natural landscapes. Episodic debris flow activity is ubiquitous in steep, low-order mountainous catchments and generates valley networks with low concavity. A physically-based model for debris flow incision (Stock and Dietrich, GSA Bull, 2006) proposes that incision rates depend on the frequency, volume, and velocity of debris flows as well as the density of trigger sites and the state of bedrock weathering in low-order valleys. Valley slope angles are predicted to decline with drainage area according to how these properties vary spatially. We calibrated the model for a well-studied small catchment in the Oregon Coast Range using cosmogenic radionuclide erosion rates and then analyzed the slope-area signature of low-order valleys across much of the Central Oregon Coast Range to explore spatial variations in baselevel lowering. This endeavor shows that baselevel lowering rates vary significantly due to patches of resistant bedrock, drainage reorganization, and tectonic forcing. In regions with weak sedimentary bedrock, earthflows can reduce hillslope gradients, promote gullying, and dominate sediment yield through their downslope translation. A one-dimensional, physically-based model for earthflow-prone hillslope evolution (Booth and Roering, JGR, in press) incorporates earthflow
Ancient DNA analysis is becoming widespread. These studies use polymerase chain reaction (PCR) to amplify minute quantities of heavily damaged template. Unusual steps are taken to achieve the sensitivity necessary to detect ancient DNA, including high- cycle PCR amplification t...
Is decreased diameter of renal pelvis in prone position an indicator of successful pyeloplasty?
Sharma, Gyanendra; Sharma, Anshu; Leung, Vivian Yee-Fong; Chu, Winnie Chiu-Wing
Objective: To evaluate patients who had undergone pyeloplasty for pelviureteric junction obstruction, by measuring the anteroposterior diameter (APD) of the renal pelvis in supine and prone positions, and determine whether a decrease in APD in prone position can exclude obstruction in dilated renal system. Materials and Methods: From January 2012 to December 2013, patients who had undergone pyeloplasty were evaluated by ultrasound in two centers. The difference of APD of the renal pelvis in supine and prone positions was obtained. Correlation was made with the pre- and post-pyeloplasty renal function by radionuclide renogram. Results: There were 42 patients (31 males, 11 females; age range 5 months to 18 years). Residual hydronephrosis was detected in 41 patients of whom 35 patients (85%) showed decrease in APD by >10% in prone position. These patients and the one without hydronephrosis showed either no deterioration or improvement in renal function. Six patients (15%) showed either no change or increase in APD in prone position. Three patients (7.5%) were confirmed to have decrease in renal function indicating obstruction. Three patients (7.5%) showed no deterioration of renal function, but sluggish drainage on radionuclide renogram. Conclusion: Demonstration of decreased APD of renal pelvis in prone position by ultrasound is useful to differentiate obstructed from non-obstructed dilated renal system, and it correctly identified 85% candidates with successful pyeloplasty. In patients with no decrease or increase in APD at prone position, further follow-up is recommended to rule out obstruction. PMID:27081219
Regional ventilation-perfusion distribution is more uniform in the prone position
NASA Technical Reports Server (NTRS)
Mure, M.; Domino, K. B.; Lindahl, S. G.; Hlastala, M. P.; Altemeier, W. A.; Glenny, R. W.
The arterial blood PO(2) is increased in the prone position in animals and humans because of an improvement in ventilation (VA) and perfusion (Q) matching. However, the mechanism of improved VA/Q is unknown. This experiment measured regional VA/Q heterogeneity and the correlation between VA and Q in supine and prone positions in pigs. Eight ketamine-diazepam-anesthetized, mechanically ventilated pigs were studied in supine and prone positions in random order. Regional VA and Q were measured using fluorescent-labeled aerosols and radioactive-labeled microspheres, respectively. The lungs were dried at total lung capacity and cubed into 603-967 small ( approximately 1.7-cm(3)) pieces. In the prone position the homogeneity of the ventilation distribution increased (P = 0.030) and the correlation between VA and Q increased (correlation coefficient = 0.72 +/- 0.08 and 0.82 +/- 0.06 in supine and prone positions, respectively, P = 0.03). The homogeneity of the VA/Q distribution increased in the prone position (P = 0.028). We conclude that the improvement in VA/Q matching in the prone position is secondary to increased homogeneity of the VA distribution and increased correlation of regional VA and Q.
Individual Differences in Emotion Regulation, Childhood Trauma and Proneness to Shame and Guilt in Adolescence
Dispositional shame and guilt have been associated with psychopathology and an increasing number of studies have traced this relation back to adolescence. This developmental period is thought to be characterized by maturational changes in emotion regulation, which also play an important role in vulnerability to psychopathology, but little is known about the links between emotion regulation and dispositional shame and guilt. The current study investigated the relations between individual differences in the habitual use of a wide range of emotion regulation strategies and proneness to shame and guilt in a large sample of adolescents (N = 706), aged 13 to 17 years. History of childhood trauma was also assessed. Our results showed that emotion regulation independently explained about 20% of the variance of shame-proneness and guilt-proneness. Higher use of maladaptive (e.g., Self-Blaming, Catastrophizing) and lower use of adaptive (e.g., Refocus on Planning, Positive Reappraisal) emotion regulation strategies were positively associated with shame-proneness. In contrast, lower use of maladaptive (e.g., Catastrophizing, Blaming Others) and higher use of adaptive (e.g., Refocus on Planning, Positive Reappraisal) emotion regulation strategies were associated with guilt-proneness, independent of the influence of childhood trauma, which also explained a relatively minor portion of guilt-proneness. Although there were age differences (i.e., rumination was used more by older adolescents, and the influence of emotion regulation on depression and anxiety symptoms increased with age) and sex differences (i.e., girls reported higher use of Putting into Perspective and Other Blaming compared to boys) in emotion regulation, age and sex were not significantly associated with proneness to shame and guilt. The positive relations with maladaptive emotion regulation underscores the dysfunctional nature of shame-proneness. Future studies could use longitudinal measures to establish that
Prone cross-table lateral view: an alternative to the invertogram in imperforate anus
Narasimharao, K.L.; Prasad, G.R.; Katariya, S.; Yadav, K.; Mitra, S.K.; Pathak, I.C.
The prone cross-table lateral radiograph provides equal or sometimes better information, compared to the invertogram, for demonstration of the level of rectal atresia in neonates. Easy positioning, better cooperation of the patient, elimination of the effect of gravity, and better delineation of the rectal gas shadow are the advantages of the prone lateral view. Among the 45 cases compared, equal findings were noted in 37, but in eight babies the level of rectal atresia was more caudal in the prone radiograph than in the invertogram.
Prone-position thoracoscopic resection of posterior mediastinal lymph node metastasis from rectal cancer.
Shirakawa, Yasuhiro; Noma, Kazuhiro; Koujima, Takeshi; Maeda, Naoaki; Tanabe, Shunsuke; Ohara, Toshiaki; Fujiwara, Toshiyoshi
Mediastinal lymph node metastasis from colorectal cancer is rare, and barely any reports have described resection of this pathology. We report herein a successful thoracoscopic resection of mediastinal lymph node metastasis in a prone position. A 65-year-old man presented with posterior mediastinal lymph node metastasis after resection of the primary rectal cancer and metachronous hepatic metastasis. Metastatic lymph nodes were resected completely using thoracoscopic surgery in the prone position, which provided advantages of minimal invasiveness, good surgical field, and reduced ergonomic burden on the surgeon. Thoracoscopic resection in the prone position was thought to have the potential to become the standard procedure of posterior mediastinal tumors.
Maidhof, Clemens
To err is human, and hence even professional musicians make errors occasionally during their performances. This paper summarizes recent work investigating error monitoring in musicians, i.e., the processes and their neural correlates associated with the monitoring of ongoing actions and the detection of deviations from intended sounds. Electroencephalography (EEG) studies reported an early component of the event-related potential (ERP) occurring before the onsets of pitch errors. This component, which can be altered in musicians with focal dystonia, likely reflects processes of error detection and/or error compensation, i.e., attempts to cancel the undesired sensory consequence (a wrong tone) a musician is about to perceive. Thus, auditory feedback seems not to be a prerequisite for error detection, consistent with previous behavioral results. In contrast, when auditory feedback is externally manipulated and thus unexpected, motor performance can be severely distorted, although not all feedback alterations result in performance impairments. Recent studies investigating the neural correlates of feedback processing showed that unexpected feedback elicits an ERP component after note onsets, which shows larger amplitudes during music performance than during mere perception of the same musical sequences. Hence, these results stress the role of motor actions for the processing of auditory information. Furthermore, recent methodological advances like the combination of 3D motion capture techniques with EEG will be discussed. Such combinations of different measures can potentially help to disentangle the roles of different feedback types such as proprioceptive and auditory feedback, and in general to derive at a better understanding of the complex interactions between the motor and auditory domain during error monitoring. Finally, outstanding questions and future directions in this context will be discussed. PMID:23898255
Errata: Papers in Error Analysis.
ERIC Educational Resources Information Center
Svartvik, Jan, Ed.
Papers presented at the symposium of error analysis in Lund, Sweden, in September 1972, approach error analysis specifically in its relation to foreign language teaching and second language learning. Error analysis is defined as having three major aspects: (1) the description of the errors, (2) the explanation of errors by means of contrastive…
How good is a PCR efficiency estimate: Recommendations for precise and robust qPCR efficiency assessments.
Svec, David; Tichopad, Ales; Novosadova, Vendula; Pfaffl, Michael W; Kubista, Mikael
We have examined the imprecision in the estimation of PCR efficiency by means of standard curves based on strategic experimental design with large number of technical replicates. In particular, how robust this estimation is in terms of a commonly varying factors: the instrument used, the number of technical replicates performed and the effect of the volume transferred throughout the dilution series. We used six different qPCR instruments, we performed 1-16 qPCR replicates per concentration and we tested 2-10 μl volume of analyte transferred, respectively. We find that the estimated PCR efficiency varies significantly across different instruments. Using a Monte Carlo approach, we find the uncertainty in the PCR efficiency estimation may be as large as 42.5% (95% CI) if standard curve with only one qPCR replicate is used in 16 different plates. Based on our investigation we propose recommendations for the precise estimation of PCR efficiency: (1) one robust standard curve with at least 3-4 qPCR replicates at each concentration shall be generated, (2) the efficiency is instrument dependent, but reproducibly stable on one platform, and (3) using a larger volume when constructing serial dilution series reduces sampling error and enables calibration across a wider dynamic range.
NASA Astrophysics Data System (ADS)
von Clarmann, T.
The difference due to the content of a priori information between a constrained retrieval and the true atmospheric state is usually represented by a diagnostic quantity called smoothing error. In this paper it is shown that, regardless of the usefulness of the smoothing error as a diagnostic tool in its own right, the concept of the smoothing error as a component of the retrieval error budget is questionable because it is not compliant with Gaussian error propagation. The reason for this is that the smoothing error does not represent the expected deviation of the retrieval from the true state but the expected deviation of the retrieval from the atmospheric state sampled on an arbitrary grid, which is itself a smoothed representation of the true state; in other words, to characterize the full loss of information with respect to the true atmosphere, the effect of the representation of the atmospheric state on a finite grid also needs to be considered. The idea of a sufficiently fine sampling of this reference atmospheric state is problematic because atmospheric variability occurs on all scales, implying that there is no limit beyond which the sampling is fine enough. Even the idealization of infinitesimally fine sampling of the reference state does not help, because the smoothing error is applied to quantities which are only defined in a statistical sense, which implies that a finite volume of sufficient spatial extent is needed to meaningfully discuss temperature or concentration. Smoothing differences, however, which play a role when measurements are compared, are still a useful quantity if the covariance matrix involved has been evaluated on the comparison grid rather than resulting from interpolation and if the averaging kernel matrices have been evaluated on a grid fine enough to capture all atmospheric variations that the instruments are sensitive to. This is, under the assumptions stated, because the undefined component of the smoothing error, which is the
Experimental investigation of observation error in anuran call surveys
McClintock, B.T.; Bailey, L.L.; Pollock, K.H.; Simons, T.R.
Occupancy models that account for imperfect detection are often used to monitor anuran and songbird species occurrence. However, presenceabsence data arising from auditory detections may be more prone to observation error (e.g., false-positive detections) than are sampling approaches utilizing physical captures or sightings of individuals. We conducted realistic, replicated field experiments using a remote broadcasting system to simulate simple anuran call surveys and to investigate potential factors affecting observation error in these studies. Distance, time, ambient noise, and observer abilities were the most important factors explaining false-negative detections. Distance and observer ability were the best overall predictors of false-positive errors, but ambient noise and competing species also affected error rates for some species. False-positive errors made up 5 of all positive detections, with individual observers exhibiting false-positive rates between 0.5 and 14. Previous research suggests false-positive errors of these magnitudes would induce substantial positive biases in standard estimators of species occurrence, and we recommend practices to mitigate for false positives when developing occupancy monitoring protocols that rely on auditory detections. These recommendations include additional observer training, limiting the number of target species, and establishing distance and ambient noise thresholds during surveys. ?? 2010 The Wildlife Society.
The importance of robust error control in data compression applications
NASA Technical Reports Server (NTRS)
Woolley, S. I.
Data compression has become an increasingly popular option as advances in information technology have placed further demands on data storage capabilities. With compression ratios as high as 100:1 the benefits are clear; however, the inherent intolerance of many compression formats to error events should be given careful consideration. If we consider that efficiently compressed data will ideally contain no redundancy, then the introduction of a channel error must result in a change of understanding from that of the original source. While the prefix property of codes such as Huffman enables resynchronisation, this is not sufficient to arrest propagating errors in an adaptive environment. Arithmetic, Lempel-Ziv, discrete cosine transform (DCT) and fractal methods are similarly prone to error propagating behaviors. It is, therefore, essential that compression implementations provide sufficient combatant error control in order to maintain data integrity. Ideally, this control should be derived from a full understanding of the prevailing error mechanisms and their interaction with both the system configuration and the compression schemes in use.
SU-E-T-307: Dosimetric Comparison of Prone Versus Supine Positioning for Adjuvant Breast Radiation Therapy
Pope, C; O'Connor, B; Hayes, L; Rella, J; Ruiz, B; Yang, J
Purpose: The prone treatment position has been used to reduce ipsilateral lung and heart dose in left breast radiation. We conducted a retrospective study to evaluate the difference in the dosimetry between prone and supine treatment positions. Methods: Eight left breast cancer patients were simulated in both the supine and prone positions as a pretreatment evaluation for the optimal treatment position. Treatment plans were created for all patients in both the supine and prone positions using a field in field three dimensional planning technique. Prescribed dose was 45 Gy delivered by two tangential photon fields. Irradiated volume (IV) was evaluated by V50, V100, and dose to lung and heart by V5, V10, V20, and the mean dose were evaluated. Results: All dosimetry metrics for both the supine and prone plans met our internal normal structure guidelines which are based on Quantec data. The average IVs (50% and 100%) were 2223cc and 1361cc prone, 2315cc and 1315cc supine. The average ipsilateral lung Mean dose (0.83Gy prone vs 5.8Gy supine), V5 (1.6% prone vs 20.9% supine), V10 (0.78% prone vs 15% supine) and V20 (0.36% prone vs 11% supine) were significantly lower in prone position. Heart Mean dose (1.4Gy prone vs 2.9Gy supine), V10 (1.4% prone vs 5.0% supine) and V20 (0.4% prone vs 3.5% supine) were found improved for all patients except one where the mean dose was the same and all other values were improved. Conclusion: The prone position offer preferable dosimetry for all patients planned in our study. These patients were chosen based on the physician's belief that they would benefit from prone treatment either because they had large pendulous breasts or due to the amount of heart seen in the field on CT simulation.
[Prone position: effect on gas exchange and functional capacity for exercise in patients with pulmonary hypertension].
Bastidas-L, Andrea Carolina; Colina-Chourio, José A; Guevara, Jesnel M; Nunez, Alexis
The objective of this investigation was to evaluate gas exchange and cardiopulmonary functional behavior in patients with pulmonary hypertension (PH) before, during and after the change to a prone position. Thirty patients with PH and alterations in gas exchange were included in the study. Gas exchange measurements were performed in four stages: at the baseline supine position and after 30, 120 and 240 minutes in prone position. Also, the patients were evaluated by the six minutes walking test (6MWT) after 30 days in prone position during night's sleep. After four hours in prone position, all patients showed an increase of PaO2 and arterial saturation of oxygen (SaO2), with a decrease of intrapulmonary shunts, improving the gas exchange and therefore the physiological demand imposed by exercise in patients with PH.
Modeling interactions betweenspotted owl and barred owl populations in fire-prone forests
Background / Question / Methods Efforts to conserve northern spotted owls (Strix occidentalis caurina) in the eastern Cascades of Washington must merge the challenges of providing sufficient structurally complex forest habitat in a fire-prone landscape with the limitations impos...
Smokers May Be Prone to Risks from Breast Cancer Radiation Therapy
... html Smokers May Be Prone to Risks From Breast Cancer Radiation Therapy Long-term chances of heart attack, ... 29, 2017 WEDNESDAY, March 29, 2017 (HealthDay News) -- Breast cancer patients who smoke have an increased risk for ...
When feeling bad leads to feeling good: guilt-proneness and affective organizational commitment.
Flynn, Francis J; Schaumberg, Rebecca L
The authors posit that higher levels of guilt-proneness are associated with higher levels of affective organizational commitment. To explain this counterintuitive link, the authors suggest that a dispositional tendency to feel guilt motivates individuals to exert greater effort on their work-related tasks that, in turn, strengthens their affinity for the organization. The authors tested this idea using a laboratory study and field data from 2 samples of working adults. Individuals who are more guilt-prone reported higher levels of organizational attachment compared with less guilt-prone individuals. Furthermore, mediation analyses indicate that the link between guilt-proneness and affective commitment is driven by greater task effort. The authors discuss the implications of these findings for understanding the affective drivers of commitment in organizations.
Expected Estimating Equation using Calibration Data for Generalized Linear Models with a Mixture of Berkson and Classical Errors in Covariates
de Dieu Tapsoba, Jean; Lee, Shen-Ming; Wang, Ching-Yun
Data collected in many epidemiological or clinical research studies are often contaminated with measurement errors that may be of classical or Berkson error type. The measurement error may also be a combination of both classical and Berkson errors and failure to account for both errors could lead to unreliable inference in many situations. We consider regression analysis in generalized linear models when some covariates are prone to a mixture of Berkson and classical errors and calibration data are available only for some subjects in a subsample. We propose an expected estimating equation approach to accommodate both errors in generalized linear regression analyses. The proposed method can consistently estimate the classical and Berkson error variances based on the available data, without knowing the mixture percentage. Its finite-sample performance is investigated numerically. Our method is illustrated by an application to real data from an HIV vaccine study. PMID:24009099
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NASA Technical Reports Server (NTRS)
A mathematical theory for development of "higher order" software to catch computer mistakes resulted from a Johnson Space Center contract for Apollo spacecraft navigation. Two women who were involved in the project formed Higher Order Software, Inc. to develop and market the system of error analysis and correction. They designed software which is logically error-free, which, in one instance, was found to increase productivity by 600%. USE.IT defines its objectives using AXES -- a user can write in English and the system converts to computer languages. It is employed by several large corporations.
A comprehensive analysis of translational missense errors in the yeast Saccharomyces cerevisiae.
Kramer, Emily B; Vallabhaneni, Haritha; Mayer, Lauren M; Farabaugh, Philip J
The process of protein synthesis must be sufficiently rapid and sufficiently accurate to support continued cellular growth. Failure in speed or accuracy can have dire consequences, including disease in humans. Most estimates of the accuracy come from studies of bacterial systems, principally Escherichia coli, and have involved incomplete analysis of possible errors. We recently used a highly quantitative system to measure the frequency of all types of misreading errors by a single tRNA in E. coli. That study found a wide variation in error frequencies among codons; a major factor causing that variation is competition between the correct (cognate) and incorrect (near-cognate) aminoacyl-tRNAs for the mutant codon. Here we extend that analysis to measure the frequency of missense errors by two tRNAs in a eukaryote, the yeast Saccharomyces cerevisiae. The data show that in yeast errors vary by codon from a low of 4 x 10(-5) to a high of 6.9 x 10(-4) per codon and that error frequency is in general about threefold lower than in E. coli, which may suggest that yeast has additional mechanisms that reduce missense errors. Error rate again is strongly influenced by tRNA competition. Surprisingly, missense errors involving wobble position mispairing were much less frequent in S. cerevisiae than in E. coli. Furthermore, the error-inducing aminoglycoside antibiotic, paromomycin, which stimulates errors on all error-prone codons in E. coli, has a more codon-specific effect in yeast.
ECG Segmentation and P-Wave Feature Extraction: Application to Patients Prone to Atrial Fibrillation
detection of patients prone to atrial fibrillation (AF), one of the most frequent arrhythmias. It focuses first on the segmentation of the...Keywords : atrial fibrillation , ECG segmentation, P-wave, hidden Markov model, wavelets, ECG database I. INTRODUCTION Atrial fibrillation (AF) is a very... atrial thrombosis, with the subsequent risk of a stroke. The aim of this study is to try to automatically detect patients prone to atrial fibrillation (AF
Prone position in acute respiratory distress syndrome. Rationale, indications, and limits.
Gattinoni, Luciano; Taccone, Paolo; Carlesso, Eleonora; Marini, John J
In the prone position, computed tomography scan densities redistribute from dorsal to ventral as the dorsal region tends to reexpand while the ventral zone tends to collapse. Although gravitational influence is similar in both positions, dorsal recruitment usually prevails over ventral derecruitment, because of the need for the lung and its confining chest wall to conform to the same volume. The final result of proning is that the overall lung inflation is more homogeneous from dorsal to ventral than in the supine position, with more homogeneously distributed stress and strain. As the distribution of perfusion remains nearly constant in both postures, proning usually improves oxygenation. Animal experiments clearly show that prone positioning delays or prevents ventilation-induced lung injury, likely due in large part to more homogeneously distributed stress and strain. Over the last 15 years, five major trials have been conducted to compare the prone and supine positions in acute respiratory distress syndrome, regarding survival advantage. The sequence of trials enrolled patients who were progressively more hypoxemic; exposure to the prone position was extended from 8 to 17 hours/day, and lung-protective ventilation was more rigorously applied. Single-patient and meta-analyses drawing from the four major trials showed significant survival benefit in patients with PaO2/FiO2 lower than 100. The latest PROSEVA (Proning Severe ARDS Patients) trial confirmed these benefits in a formal randomized study. The bulk of data indicates that in severe acute respiratory distress syndrome, carefully performed prone positioning offers an absolute survival advantage of 10-17%, making this intervention highly recommended in this specific population subset.
Exploring the relationship between boredom proneness and self-control in traumatic brain injury (TBI).
Isacescu, Julia; Danckert, James
Characterized as an agitated state in which the individual is motivated to engage in their environment but all attempts to do so fail to satisfy, boredom represents a disengaged attentional state that is associated with negative affect and poor self-control. There have been anecdotal reports of increased levels of boredom post-traumatic brain injury (TBI). For the first time, we provide objective evidence that TBI patients do indeed experience higher levels of boredom proneness. Hierarchical regression analyses showed that the presence and severity of head injury were a significant positive predictor of levels of boredom proneness and a negative predictor of self-control. As with healthy controls, TBI patients showed a strong negative correlation between boredom proneness and self-control-those with lower levels of self-control exhibited higher levels of boredom proneness. This was despite the fact that our TBI patients reported higher overall levels of self-control (probably concomitant with their older mean age). The TBI patients also showed strong positive correlations between boredom proneness and measures of physical aggression and anger. Together, this suggests that patients with TBI may be more susceptible to increased levels of boredom proneness and other negative affective states that arise as a consequence of failures of self-control.
An analysis on muscle tone and stiffness during sling exercise on static prone position
Kim, Jeong-Ja
[Purpose] The purpose of this study was to examine changes in the muscle tone and stiffness of the lumbar region while individuals adopted the static prone position using sling suspension. [Subjects and Methods] The subjects were 30 healthy women in their 20s. The muscle tone and stiffness of the upper and lower lumbar regions of the sling suspension group and a control group were measured using myotonmetory as they maintained the static prone positon. [Results] The sling suspension group showed statistically significant declines in the muscle tone and stiffness of the upper lumbar region 5–10 min after adopting the initial prone position. They also showed statistically significant declines in the muscle tone and stiffness of the lower lumbar region immediately after being suspended in the slings and a statistically significant decline in the muscle tone of the lower lumbar region 5–10 min after adopting the initial prone position during which the sling suspension was applied. In contrast, the muscle tone and stiffness of the lumbar region of the control group increased while maintaining the static prone position. [Conclusion] The static prone position performed on a treatment table using sling suspension can be an effective intervention for reducing the muscle tone and stiffness of the lumbar region. PMID:28174469
Vocational interests and career indecision among psychosis-prone college students.
Poreh, A M; Schullen, C
This study investigated the relationship between scores on scales that purport to measure psychosis-proneness and scores on vocational interests, identity, and differentiation scales in a sample of 233 college students who completed the Perceptual Aberration and Magical Ideation scales, the Strong Campbell Interest Inventory, and the Career Decision Scale. The present findings are consistent with prior work indicating a sex-related association of scores on measures of psychosis-proneness and vocational interests. A positive correlation between scores on vocational indecision and measures of psychosis-proneness was also found, suggesting that both men and women who score high on psychosis-proneness find it difficult to formulate long-term career goals. Finally, there was no significant correlation between scores on measures of psychosis-proneness and Holland's Vocational Differentiation Index. Present results are discussed in light of previously reported sex differences among psychosis-prone adults and diagnosed schizophrenics. The implications of the findings for vocational counselors are also addressed.
Delusion proneness in nonclinical individuals and cognitive insight: the contributions of rumination and reflection.
Carse, Traci; Langdon, Robyn
Although previous research demonstrates that clinical individuals with delusions score low on one of the facets of cognitive insight, self-reflection, and high on the other facet, self-certainty, analogous studies of delusion proneness in nonclinical individuals have found that delusion proneness in nonclinical individuals associates with higher levels of both self-certainty and self-reflection. The present study sought to reconcile these inconsistent results by examining the contributions of different facets of self-reflection, rumination and reflection, to delusion proneness. One hundred fifty-two individuals completed three questionnaires: the Beck Cognitive Insight Scale (BCIS), the Peters et al. Delusions Inventory (PDI), and the Rumination-Reflection Questionnaire (RRQ). The results showed that the individuals scoring higher on delusion proneness demonstrated higher levels of both self-certainty and self-reflection on the BCIS as well as higher levels of rumination and reflection on the RRQ. As predicted, the strength of the relationship between BCIS self-reflection and delusion proneness was diminished when rumination was controlled for. These findings suggest that the previously observed positive relation between BCIS self-reflection and nonclinical delusion proneness might be driven, in part, by the ruminative aspect of self-reflection.
Design and Evaluation of a Stand-Up Motorized Prone Cart
Harrow, Jeffrey J; Malassigné, Pascal; Nelson, Audrey L; Jensen, Robert P; Amato, Margaret; Palacios, Polly L
Background/Objective: Prone carts are used for mobility by individuals with spinal cord injury in whom seated mobility (wheelchair) is contraindicated due to ischial or sacral pressure ulcers. Currently available prone carts are uncomfortable, subjecting the user to neck and shoulder strain, and make social interaction and performing activities of daily living difficult. A better design of prone carts is needed. In addition, standing devices have shown some medical benefits. The objective was to design and evaluate an improved prone cart that facilitates standing. Design: Engineering development project with user feedback through questionnaire. Users selected by convenience sampling. Methods: A marketing survey was performed of nurse managers of spinal cord injury units. Then 2 prototype carts were designed and built. These carts are able to tilt up to 45° and have a joystick-controlled motor for propulsion and other design features, including a workspace storage shelf and rearview mirrors. The carts were evaluated by both patients and caregivers at 2 Veteran's Administration hospitals. Outcome Measures: Questionnaire of subjects, both patients and caregivers, who used the cart. Findings: Both patients and caregivers liked the carts and the ability to assume a nonhorizontal body angle. The major complaint about the cart was that it seemed too long when it came to making turns. Conclusion: This prone cart design is an improvement over the standard, flat variety. However, further design changes will be necessary. This study provided valuable information that will be useful in the next-generation prone cart design project. PMID:17385270
Efficacy of prone position in acute respiratory distress syndrome patients: A pathophysiology-based review
Koulouras, Vasilios; Papathanakos, Georgios; Papathanasiou, Athanasios; Nakos, Georgios
Acute respiratory distress syndrome (ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mortality. The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. Prone positioning is a supplementary strategy available in managing patients with ARDS. It was first described 40 years ago and it proves to be in alignment with two major ARDS pathophysiological lung models; the "sponge lung" - and the "shape matching" -model. Current evidence strongly supports that prone positioning has beneficial effects on gas exchange, respiratory mechanics, lung protection and hemodynamics as it redistributes transpulmonary pressure, stress and strain throughout the lung and unloads the right ventricle. The factors that individually influence the time course of alveolar recruitment and the improvement in oxygenation during prone positioning have not been well characterized. Although patients' response to prone positioning is quite variable and hard to predict, large randomized trials and recent meta-analyses show that prone position in conjunction with a lung-protective strategy, when performed early and in sufficient duration, may improve survival in patients with ARDS. This pathophysiology-based review and recent clinical evidence strongly support the use of prone positioning in the early management of severe ARDS systematically and not as a rescue maneuver or a last-ditch effort. PMID:27152255
Children's Proneness to Shame and Guilt Predict Risky and Illegal Behaviors in Young Adulthood
Stuewig, Jeffrey; Tangney, June P.; Kendall, Stephanie; Folk, Johanna B.; Meyer, Candace Reinsmith; Dearing, Ronda L.
Do shame and guilt help people avoid doing wrong? Although some research suggests that guilt-proneness is a protective factor while shame-proneness puts individuals at risk, most research is either cross-sectional or short-term. In this longitudinal study, 380 5th graders (ages 10–12) completed measures of proneness to shame and guilt. We re-interviewed 68% of participants after they turned 18 years old (range 18–21). Guilt-proneness assessed in childhood predicted fewer sexual partners, less use of illegal drugs and alcohol, and less involvement with the criminal justice system. Shame-proneness, in contrast, was a risk factor for later deviant behavior. Shame-prone children were more likely to have unprotected sex and use illegal drugs in young adulthood. These results held when controlling for childhood SES and teachers' ratings of aggression. Children's moral emotional styles appear to be well established by at least middle childhood, with distinct downstream implications for risky behavior in early adulthood. PMID:24842762
ERIC Educational Resources Information Center
Julian, Liam
In this article, the author talks about George Orwell, his instructive errors, and the manner in which Orwell pierced worthless theory, faced facts and defended decency (with fluctuating success), and largely ignored the tradition of accumulated wisdom that has rendered him a timeless teacher--one whose inadvertent lessons, while infrequently…
E-prescribing errors identified in a compounding pharmacy: a quality-improvement project.
Reed-Kane, Dana; Kittell, Katrina; Adkins, Jacquelyn; Flocks, Sarah; Nguyen, Thu
Errors during the prescribing process can cause problems for patients. When the pharmacist intercepts a prescribing error, it can cause a delay, as the patient may not receive the medication until the problem is resolved. Electronic prescriptions are purported to reduce prescribing errors. However, studies have shown that electronic prescriptions can be prone to certain types of errors. Compounding pharmacies may present an additional obstacle for e-prescribing, as the prescribed medications are not commercially available and may not be listed in the e-prescribing software. The objectives of this study were to estimate the electronic prescription error rate in a compounding pharmacy, determine the most common error types, list the most common interventions pharmacists made, and estimate how long it took to resolve these errors. The study design was quality improvement with descriptive data. During the four weeks of data collection, the pharmacists were trained to complete a standardized data collection form when they identified an electronic prescription error. Percentages were calculated for new prescriptions, electronic prescriptions with errors, error types, and error resolution methods. In the four-week period of the study, there were 982 new prescriptions, 111 of which were electronic prescriptions. Of those 111 electronic prescriptions, 70 had errors. The electronic prescriptions error rate was 63%. The most common type of error was wrong entry field (70.3%). For this project, wrong entry field was defined to mean that the drug name was in the wrong field (81%) or that multiple entries were in the wrong field (7%). Pharmacists usually used their own judgment to resolve an error (67%). Many e-prescription errors were identified in this compounding pharmacy. When prescription errors happen, workflow and patient care are disrupted. Our goal is to discuss these findings with Surescripts and e-prescribing software companies to seek systems-based solutions.
Report of the Subpanel on Error Characterization and Error Budgets
NASA Technical Reports Server (NTRS)
The state of knowledge of both user positioning requirements and error models of current and proposed satellite systems is reviewed. In particular the error analysis models for LANDSAT D are described. Recommendations are given concerning the geometric error model for the thematic mapper; interactive user involvement in system error budgeting and modeling and verification on real data sets; and the identification of a strawman mission for modeling key error sources.
Enhanced Named Entity Extraction via Error-Driven Aggregation
Lemmond, T D; Perry, N C; Guensche, J W; Nitao, J J; Glaser, R E; Kidwell, P; Hanley, W G
Despite recent advances in named entity extraction technologies, state-of-the-art extraction tools achieve insufficient accuracy rates for practical use in many operational settings. However, they are not generally prone to the same types of error, suggesting that substantial improvements may be achieved via appropriate combinations of existing tools, provided their behavior can be accurately characterized and quantified. In this paper, we present an inference methodology for the aggregation of named entity extraction technologies that is founded upon a black-box analysis of their respective error processes. This method has been shown to produce statistically significant improvements in extraction relative to standard performance metrics and to mitigate the weak performance of entity extractors operating under suboptimal conditions. Moreover, this approach provides a framework for quantifying uncertainty and has demonstrated the ability to reconstruct the truth when majority voting fails.
Automatic Error Analysis Using Intervals
ERIC Educational Resources Information Center
Rothwell, E. J.; Cloud, M. J.
A technique for automatic error analysis using interval mathematics is introduced. A comparison to standard error propagation methods shows that in cases involving complicated formulas, the interval approach gives comparable error estimates with much less effort. Several examples are considered, and numerical errors are computed using the INTLAB…
Control by model error estimation
NASA Technical Reports Server (NTRS)
Likins, P. W.; Skelton, R. E.
Modern control theory relies upon the fidelity of the mathematical model of the system. Truncated modes, external disturbances, and parameter errors in linear system models are corrected by augmenting to the original system of equations an 'error system' which is designed to approximate the effects of such model errors. A Chebyshev error system is developed for application to the Large Space Telescope (LST).
ERIC Educational Resources Information Center
Rieger, Martina; Martinez, Fanny; Wenke, Dorit
Using a typing task we investigated whether insufficient imagination of errors and error corrections is related to duration differences between execution and imagination. In Experiment 1 spontaneous error imagination was investigated, whereas in Experiment 2 participants were specifically instructed to imagine errors. Further, in Experiment 2 we…
Speech Errors across the Lifespan
ERIC Educational Resources Information Center
Vousden, Janet I.; Maylor, Elizabeth A.
Dell, Burger, and Svec (1997) proposed that the proportion of speech errors classified as anticipations (e.g., "moot and mouth") can be predicted solely from the overall error rate, such that the greater the error rate, the lower the anticipatory proportion (AP) of errors. We report a study examining whether this effect applies to changes in error…
Situating Student Errors: Linguistic-to-Algebra Translation Errors
ERIC Educational Resources Information Center
Adu-Gyamfi, Kwaku; Bossé, Michael J.; Chandler, Kayla
While it is well recognized that students are prone to difficulties when performing linguistic-to-algebra translations, the nature of students' difficulties remain an issue of contention. Moreover, the literature indicates that these difficulties are not easily remediated by domain-specific instruction. Some have opined that this is the case…
Intraoperative visualization and assessment of electromagnetic tracking error
NASA Astrophysics Data System (ADS)
Harish, Vinyas; Ungi, Tamas; Lasso, Andras; MacDonald, Andrew; Nanji, Sulaiman; Fichtinger, Gabor
Electromagnetic tracking allows for increased flexibility in designing image-guided interventions, however it is well understood that electromagnetic tracking is prone to error. Visualization and assessment of the tracking error should take place in the operating room with minimal interference with the clinical procedure. The goal was to achieve this ideal in an open-source software implementation in a plug and play manner, without requiring programming from the user. We use optical tracking as a ground truth. An electromagnetic sensor and optical markers are mounted onto a stylus device, pivot calibrated for both trackers. Electromagnetic tracking error is defined as difference of tool tip position between electromagnetic and optical readings. Multiple measurements are interpolated into the thin-plate B-spline transform visualized in real time using 3D Slicer. All tracked devices are used in a plug and play manner through the open-source SlicerIGT and PLUS extensions of the 3D Slicer platform. Tracking error was measured multiple times to assess reproducibility of the method, both with and without placing ferromagnetic objects in the workspace. Results from exhaustive grid sampling and freehand sampling were similar, indicating that a quick freehand sampling is sufficient to detect unexpected or excessive field distortion in the operating room. The software is available as a plug-in for the 3D Slicer platforms. Results demonstrate potential for visualizing electromagnetic tracking error in real time for intraoperative environments in feasibility clinical trials in image-guided interventions.
Whole-breast irradiation: a subgroup analysis of criteria to stratify for prone position treatment
Ramella, Sara; Trodella, Lucio; Ippolito, Edy; Fiore, Michele; Cellini, Francesco; Stimato, Gerardina; Gaudino, Diego; Greco, Carlo; Ramponi, Sara; Cammilluzzi, Eugenio; Cesarini, Claudio; Piermattei, Angelo; Cesario, Alfredo; D'Angelillo, Rolando Maria
To select among breast cancer patients and according to breast volume size those who may benefit from 3D conformal radiotherapy after conservative surgery applied with prone-position technique. Thirty-eight patients with early-stage breast cancer were grouped according to the target volume (TV) measured in the supine position: small ({<=}400 mL), medium (400-700 mL), and large ({>=}700 ml). An ad-hoc designed and built device was used for prone set-up to displace the contralateral breast away from the tangential field borders. All patients underwent treatment planning computed tomography in both the supine and prone positions. Dosimetric data to explore dose distribution and volume of normal tissue irradiated were calculated for each patient in both positions. Homogeneity index, hot spot areas, the maximum dose, and the lung constraints were significantly reduced in the prone position (p < 0.05). The maximum heart distance and the V{sub 5Gy} did not vary consistently in the 2 positions (p = 0.06 and p = 0.7, respectively). The number of necessary monitor units was significantly higher in the supine position (312 vs. 232, p < 0.0001). The subgroups analysis pointed out the advantage in lung sparing in all TV groups (small, medium and large) for all the evaluated dosimetric constraints (central lung distance, maximum lung distance, and V{sub 5Gy}, p < 0.0001). In the small TV group, a dose reduction in nontarget areas of 22% in the prone position was detected (p = 0.056); in the medium and high TV groups, the difference was of about -10% (p = NS). The decrease in hot spot areas in nontarget tissues was 73%, 47%, and 80% for small, medium, and large TVs in the prone position, respectively. Although prone breast radiotherapy is normally proposed in patients with breasts of large dimensions, this study gives evidence of dosimetric benefit in all patient subgroups irrespective of breast volume size.
Hyponatremia: management errors.
Seo, Jang Won; Park, Tae Jin
Rapid correction of hyponatremia is frequently associated with increased morbidity and mortality. Therefore, it is important to estimate the proper volume and type of infusate required to increase the serum sodium concentration predictably. The major common management errors during the treatment of hyponatremia are inadequate investigation, treatment with fluid restriction for diuretic-induced hyponatremia and treatment with fluid restriction plus intravenous isotonic saline simultaneously. We present two cases of management errors. One is about the problem of rapid correction of hyponatremia in a patient with sepsis and acute renal failure during continuous renal replacement therapy in the intensive care unit. The other is the case of hypothyroidism in which hyponatremia was aggravated by intravenous infusion of dextrose water and isotonic saline infusion was erroneously used to increase serum sodium concentration.
NASA Technical Reports Server (NTRS)
001 is an integrated tool suited for automatically developing ultra reliable models, simulations and software systems. Developed and marketed by Hamilton Technologies, Inc. (HTI), it has been applied in engineering, manufacturing, banking and software tools development. The software provides the ability to simplify the complex. A system developed with 001 can be a prototype or fully developed with production quality code. It is free of interface errors, consistent, logically complete and has no data or control flow errors. Systems can be designed, developed and maintained with maximum productivity. Margaret Hamilton, President of Hamilton Technologies, also directed the research and development of USE.IT, an earlier product which was the first computer aided software engineering product in the industry to concentrate on automatically supporting the development of an ultrareliable system throughout its life cycle. Both products originated in NASA technology developed under a Johnson Space Center contract.
Sandford, II, Maxwell T.; Handel, Theodore G.; Ettinger, J. Mark
A method of embedding auxiliary information into the digital representation of host data containing noise in the low-order bits. The method applies to digital data representing analog signals, for example digital images. The method reduces the error introduced by other methods that replace the low-order bits with auxiliary information. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user through use of a digital key. The modular error embedding method includes a process to permute the order in which the host data values are processed. The method doubles the amount of auxiliary information that can be added to host data values, in comparison with bit-replacement methods for high bit-rate coding. The invention preserves human perception of the meaning and content of the host data, permitting the addition of auxiliary data in the amount of 50% or greater of the original host data.
The Diagnosis of Error in Histories of Science
NASA Astrophysics Data System (ADS)
Thomas, William
Whether and how to diagnose error in the history of science is a contentious issue. For many scientists, diagnosis is appealing because it allows them to discuss how knowledge can progress most effectively. Many historians disagree. They consider diagnosis inappropriate because it may discard features of past actors' thought that are important to understanding it, and may have even been intellectually productive. Ironically, these historians are apt to diagnose flaws in scientists' histories as proceeding from a misguided desire to idealize scientific method, and from their attendant identification of deviations from the ideal as, ipso facto, a paramount source of error in historical science. While both views have some merit, they should be reconciled if a more harmonious and productive relationship between the disciplines is to prevail. In To Explain the World, Steven Weinberg narrates the slow but definite emergence of what we call science from long traditions of philosophical and mathematical thought. This narrative follows in a historiographical tradition charted by historians such as Alexandre Koyre and Rupert Hall about sixty years ago. It is essentially a history of the emergence of reliable (if fallible) scientific method from more error-prone thought. While some historians such as Steven Shapin view narratives of this type as fundamentally error-prone, I do not view such projects as a priori illegitimate. They are, however, perhaps more difficult than Weinberg supposes. In this presentation, I will focus on two of Weinberg's strong historical claims: that physics became detached from religion as early as the beginning of the eighteenth century, and that physics proved an effective model for placing other fields on scientific grounds. While I disagree with these claims, they represent at most an overestimation of vintage science's interest in discarding theological questions, and an overestimation of that science's ability to function at all reliably.
NASA Technical Reports Server (NTRS)
Hinds, Erold W. (Principal Investigator)
This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.
Surface temperature measurement errors
Keltner, N.R.; Beck, J.V.
Mathematical models are developed for the response of surface mounted thermocouples on a thick wall. These models account for the significant causes of errors in both the transient and steady-state response to changes in the wall temperature. In many cases, closed form analytical expressions are given for the response. The cases for which analytical expressions are not obtained can be easily evaluated on a programmable calculator or a small computer.
A semiparametric copula method for Cox models with covariate measurement error.
Kim, Sehee; Li, Yi; Spiegelman, Donna
We consider measurement error problem in the Cox model, where the underlying association between the true exposure and its surrogate is unknown, but can be estimated from a validation study. Under this framework, one can accommodate general distributional structures for the error-prone covariates, not restricted to a linear additive measurement error model or Gaussian measurement error. The proposed copula-based approach enables us to fit flexible measurement error models, and to be applicable with an internal or external validation study. Large sample properties are derived and finite sample properties are investigated through extensive simulation studies. The methods are applied to a study of physical activity in relation to breast cancer mortality in the Nurses' Health Study.
A non-orthogonal SVD-based decomposition for phase invariant error-related potential estimation.
Phlypo, Ronald; Jrad, Nisrine; Rousseau, Sandra; Congedo, Marco
The estimation of the Error Related Potential from a set of trials is a challenging problem. Indeed, the Error Related Potential is of low amplitude compared to the ongoing electroencephalographic activity. In addition, simple summing over the different trials is prone to errors, since the waveform does not appear at an exact latency with respect to the trigger. In this work, we propose a method to cope with the discrepancy of these latencies of the Error Related Potential waveform and offer a framework in which the estimation of the Error Related Potential waveform reduces to a simple Singular Value Decomposition of an analytic waveform representation of the observed signal. The followed approach is promising, since we are able to explain a higher portion of the variance of the observed signal with fewer components in the expansion.
Bayesian Error Estimation Functionals
NASA Astrophysics Data System (ADS)
Jacobsen, Karsten W.
The challenge of approximating the exchange-correlation functional in Density Functional Theory (DFT) has led to the development of numerous different approximations of varying accuracy on different calculated properties. There is therefore a need for reliable estimation of prediction errors within the different approximation schemes to DFT. The Bayesian Error Estimation Functionals (BEEF) have been developed with this in mind. The functionals are constructed by fitting to experimental and high-quality computational databases for molecules and solids including chemisorption and van der Waals systems. This leads to reasonably accurate general-purpose functionals with particual focus on surface science. The fitting procedure involves considerations on how to combine different types of data, and applies Tikhonov regularization and bootstrap cross validation. The methodology has been applied to construct GGA and metaGGA functionals with and without inclusion of long-ranged van der Waals contributions. The error estimation is made possible by the generation of not only a single functional but through the construction of a probability distribution of functionals represented by a functional ensemble. The use of the functional ensemble is illustrated on compound heat of formation and by investigations of the reliability of calculated catalytic ammonia synthesis rates.
Sources of Error in Mammalian Genetic Screens
Sack, Laura Magill; Davoli, Teresa; Xu, Qikai; Li, Mamie Z.; Elledge, Stephen J.
Genetic screens are invaluable tools for dissection of biological phenomena. Optimization of such screens to enhance discovery of candidate genes and minimize false positives is thus a critical aim. Here, we report several sources of error common to pooled genetic screening techniques used in mammalian cell culture systems, and demonstrate methods to eliminate these errors. We find that reverse transcriptase-mediated recombination during retroviral replication can lead to uncoupling of molecular tags, such as DNA barcodes (BCs), from their associated library elements, leading to chimeric proviral genomes in which BCs are paired to incorrect ORFs, shRNAs, etc. This effect depends on the length of homologous sequence between unique elements, and can be minimized with careful vector design. Furthermore, we report that residual plasmid DNA from viral packaging procedures can contaminate transduced cells. These plasmids serve as additional copies of the PCR template during library amplification, resulting in substantial inaccuracies in measurement of initial reference populations for screen normalization. The overabundance of template in some samples causes an imbalance between PCR cycles of contaminated and uncontaminated samples, which results in a systematic artifactual depletion of GC-rich library elements. Elimination of contaminating plasmid DNA using the bacterial endonuclease Benzonase can restore faithful measurements of template abundance and minimize GC bias. PMID:27402361
Dry-reagent-based PCR as a novel tool for the rapid detection of Clostridium spp.
Seise, Barbara; Pollok, Sibyll; Seyboldt, Christian; Weber, Karina
Improved conventional PCR techniques are required for the rapid on-site detection of human and animal diseases. In this context, a PCR method using dry-stored reagents intended for the detection of Clostridium spp. is presented. Basic PCR reagents (BSA, PCR buffer, MgCl₂ and primers), which were dried on polyolefin matrices, showed stability at ambient temperatures for up to 10 months without any loss of functionality. An outstanding advantage of our amelioration is the elimination of PCR process errors caused by the improper storage and handling of liquid reagents. Moreover, our PCR-based amplification can be performed in less than 30 min, saving time compared with conventional detection methods. Thus, dry-reagent-based PCR is implementable in a suitcase-like modular device for the rapid on-site detection of microbial pathogens such as blackleg of ruminants caused by Clostridium chauvoei.
RNA polymerase errors cause splicing defects and can be regulated by differential expression of RNA polymerase subunits
Carey, Lucas B
Errors during transcription may play an important role in determining cellular phenotypes: the RNA polymerase error rate is >4 orders of magnitude higher than that of DNA polymerase and errors are amplified >1000-fold due to translation. However, current methods to measure RNA polymerase fidelity are low-throughout, technically challenging, and organism specific. Here I show that changes in RNA polymerase fidelity can be measured using standard RNA sequencing protocols. I find that RNA polymerase is error-prone, and these errors can result in splicing defects. Furthermore, I find that differential expression of RNA polymerase subunits causes changes in RNA polymerase fidelity, and that coding sequences may have evolved to minimize the effect of these errors. These results suggest that errors caused by RNA polymerase may be a major source of stochastic variability at the level of single cells. DOI: http://dx.doi.org/10.7554/eLife.09945.001 PMID:26652005
Hip rotation range of motion in sitting and prone positions in healthy Japanese adults
Han, Heonsoo; Kubo, Akira; Kurosawa, Kazuo; Maruichi, Shizuka; Maruyama, Hitoshi
[Purpose] The aim of this study was to elucidate the difference in hip external and internal rotation ranges of motion (ROM) between the prone and sitting positions. [Subjects] The subjects included 151 students. [Methods] Hip rotational ROM was measured with the subjects in the prone and sitting positions. Two-way repeated measures analysis of variance (ANOVA) was used to analyze ipsilateral hip rotation ROM in the prone and sitting positions in males and females. The total ipsilateral hip rotation ROM was calculated by adding the measured values for external and internal rotations. [Results] Ipsilateral hip rotation ROM revealed significant differences between two positions for both left and right internal and external rotations. Hip rotation ROM was significantly higher in the prone position than in the sitting position. Hip rotation ROM significantly differed between the men and women. Hip external rotation ROM was significantly higher in both positions in men; conversely, hip internal rotation ROM was significantly higher in both positions in women. [Conclusion] Hip rotation ROM significantly differed between the sexes and between the sitting and prone positions. Total ipsilateral hip rotation ROM, total angle of external rotation, and total angle of internal rotation of the left and right hips greatly varied, suggesting that hip joint rotational ROM is widely distributed. PMID:25729186
Relationship between childhood trauma, mindfulness, and dissociation in subjects with and without hallucination proneness.
Perona-Garcelán, Salvador; García-Montes, José M; Rodríguez-Testal, Juan Francisco; López-Jiménez, Ana Ma; Ruiz-Veguilla, Miguel; Ductor-Recuerda, María Jesús; Benítez-Hernández, María del Mar; Arias-Velarde, Ma Ángeles; Gómez-Gómez, María Teresa; Pérez-Álvarez, Marino
The purpose of this study was to examine the relationship between childhood traumas, mindfulness, and dissociation (more specifically, absorption and depersonalization) in healthy subjects with and without hallucination proneness. A sample of 318 subjects was given the Launay-Slade Hallucination Scale-Revised (R. P. Bentall & P. Slade, 1985). From this sample, 2 groups were formed: one with high and the other with low hallucination proneness. Furthermore, all participants were given the Tellegen Absorption Scale (A. Tellegen & G. Atkinson, 1974), the Cambridge Depersonalization Scale (M. Sierra & G. E. Berrios, 2000), the Southampton Mindfulness Questionnaire (P. D. J. Chadwick et al., 2008), and the Trauma Questionnaire (J. R. E. Davidson, D. Hughes, & D. G. Blazer, 1990). The results showed that in the group with high hallucination proneness, there were significantly more subjects with traumatic experiences than in the group with low predisposition, although no significant difference in the mean number of traumatic experiences undergone in childhood was found between the 2 groups, although there was a trend toward significance. A correlation analysis showed a significant negative association between mindfulness on the one hand and absorption and depersonalization on the other. A positive relationship was also found between childhood traumas and absorption and depersonalization. Finally, multiple mediation analysis showed that the absorption and depersonalization variables acted as mediators between childhood traumas and hallucination proneness. We discuss the importance of the relationship between the variables studied and hallucination proneness and suggest some approaches for their treatment.
Aggregate-prone desmin mutations impair mitochondrial calcium uptake in primary myotubes.
Smolina, Natalia; Bruton, Joseph; Sjoberg, Gunnar; Kostareva, Anna; Sejersen, Thomas
Desmin, being a major intermediate filament of mature muscle cell, interacts with mitochondria within the cell and participates in mitochondria proper localization. The goal of the present study was to assess the effect of aggregate-prone and non-aggregate-prone desmin mutations on mitochondrial calcium uptake. Primary murine satellite cells were transduced with lentiviruses carrying desmin in wild type or mutant form, and were induced to differentiate into myotubes. Four mutations resulting in different degree of desmin aggregates formation were analyzed. Tail domain mutation Asp399Tyr has the mildest impact on desmin filament polymerization, rod domain mutation Ala357Pro causes formation of large aggregates composed of filamentous material, and Leu345Pro and Leu370Pro are considered to be the most severest in their impact on desmin polymerization and structure. For mitochondrial calcium measurement cells were loaded with rhod 2-AM. We found that aggregate-prone mutations significantly decreased [Ca(2+)]mit, whereas non-aggregate-prone mutations did not decrease [Ca(2+)]mit. Moreover aggregate-prone desmin mutations resulted in increased resting cytosolic [Ca(2+)]. However this increase was not accompanied by any alterations in sarcoplasmic reticulum calcium release. We suggest that the observed decline in [Ca(2+)]mit was due to desmin aggregate accumulation resulting in the loss of desmin mitochondria interactions.
Perceived threat mediates the relationship between psychosis proneness and aggressive behavior.
Fanning, Jennifer Renee; Berman, Mitchell Eric; Mohn, Richard Samuel; McCloskey, Michael Sean
Psychotic symptoms are associated with aggressive tendencies, but this relationship is both complex and imperfect. In contrast to psychotic disorders, little is known about aggressive behavior and sub-clinical psychotic symptoms (e.g., "psychosis proneness"), which are relatively common in the general population. Threat/control-override (TCO), which is the propensity to overestimate the likelihood that an outside agent will (1) inflict harm (threat) or (2) control one's behaviors (control-override), has been associated with aggression in both psychiatric and community samples. The purpose of this study was to determine if psychosis proneness is related to aggression, and if one or both aspects of TCO mediate this relationship. We hypothesized that the propensity to overestimate threat would mediate this relationship, but control-override would not. Sixty men and sixty women (mean age=20.00 years, sd=3.00) with no history of psychotic disorder completed measures assessing psychosis proneness, threat control/override, aggressive history, aggressive ideation, and aggressive behavior. Three structural equation models were tested: (1) Threat and control-override modeled as separate mediating variables, (2) TCO as a unitary mediating latent construct, and (3) TCO considered as part of a psychosis proneness latent variable. Results indicated that psychosis proneness is positively related to aggression and that the best model fit was obtained when threat and control-override were modeled as separate variables, with mediation through threat alone. The utility of TCO for explaining the relation between psychosis spectrum symptoms and aggression is discussed.
Clarifying the Link Between Job Satisfaction and Absenteeism: The Role of Guilt Proneness.
Schaumberg, Rebecca L; Flynn, Francis J
We propose that the relationship between job satisfaction and absenteeism depends partly on guilt proneness. Drawing on withdrawal and process models of absenteeism, we argue that job satisfaction predicts absences for employees who are low (but not high) in guilt proneness because low guilt-prone people's behaviors are governed more by fulfilling their own egoistic desires than by fulfilling others' normative expectations. We find support for this prediction in a sample of customer service agents working for a major telecommunications company and a sample of working adults employed in a range of industries. In each study, we use measures of employees' guilt proneness and job satisfaction to predict their subsequent workplace absences. In Study 2, we extend our hypothesis tests to 2 traits that are conceptually comparable to guilt proneness (i.e., moral identity and agreeableness), showing that these traits similarly moderate the relationship between job satisfaction and absenteeism. We discuss the implications of these findings for extant models of absenteeism and research on moral affectivity in the workplace. (PsycINFO Database Record
SU-E-T-538: Does Abdominal Compression Through Prone Patient Position Reduce Respiratory Motion in Lung Cancer Radiotherapy?
Catron, T; Rosu, M; Weiss, E
Purpose: This study assesses the effect of physiological abdominal compression from prone positioning by comparing respiratory-induced tumor movements in supine and prone positions. Methods: 19 lung cancer patients underwent repeated supine and prone free-breathing 4DCT scans. The effect of patient position on motion magnitude was investigated for tumors, lymph nodes (9 cases), and subgroups of central (11 cases), peripheral (8 cases) and small peripheral tumors (5 cases), by evaluating the population average excursions, absolute and relative to a carina-point. Results: Absolute motion analysis: In prone, motion increased by ~20% for tumors and ~25% for lymph nodes. Central tumors moved more compared to peripheral tumors in both supine and prone (~22%, and ~4% respectively). Central tumors movement increased by ~12% in prone. For peripheral tumors the increase in prone position was ~25% (~40% and 29% changes on along RL and AP directions). Motion relative to carina-point analysis: Overall, tumor excursions relative to carina-point increased by ~17% in prone. Lymph node relative magnitudes were lower by ~4%. Likewise, the central tumors moved ~7% less in prone. The subgroup of peripheral tumors exhibited increased amplitudes by ~44%; the small peripheral tumors had even larger relative displacements in prone (~46%). Conclusion: Tumor and lymph node movement in the patient population from this study averaged to be higher in prone than in supine position. Results from carina analysis also suggest that peripheral tissues have more physiologic freedom of motility when placed in the prone position, regardless of size. From these observations we should continue to avoid prone positioning for all types of primary lung tumor, suggesting that patients should receive radiotherapy for primary lung cancer in supine position to minimize target tissue mobility during normal respiratory effort. Further investigation will include more patients with peripheral tumors to validate our
NASA Technical Reports Server (NTRS)
Tubbs, Eldred F.
A two-step approach to wavefront sensing for the Large Deployable Reflector (LDR) was examined as part of an effort to define wavefront-sensing requirements and to determine particular areas for more detailed study. A Hartmann test for coarse alignment, particularly segment tilt, seems feasible if LDR can operate at 5 microns or less. The direct measurement of the point spread function in the diffraction limited region may be a way to determine piston error, but this can only be answered by a detailed software model of the optical system. The question of suitable astronomical sources for either test must also be addressed.
unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 DETECTING ERRORS IN PROGRAMS* Lloyd D. Fosdick...from a finite set of tests [35,36]a Recently Howden [37] presented a result showing that for a particular class of Lindenmayer grammars it was possible...Diego, CA. 37o Howden, W.E.: Lindenmayer grammars and symbolic testing. Information Processing Letters 7,1 (Jano 1978), 36-39. 38~ Fitzsimmons, Ann
Endoplasmic reticulum stress caused by aggregate-prone proteins containing homopolymeric amino acids.
Uchio, Naohiro; Oma, Yoko; Toriumi, Kazuya; Sasagawa, Noboru; Tanida, Isei; Fujita, Eriko; Kouroku, Yoriko; Kuroda, Reiko; Momoi, Takashi; Ishiura, Shoichi
Many human proteins have homopolymeric amino acid (HPAA) tracts, but their physiological functions or cellular effects are not well understood. Previously, we expressed 20 HPAAs in mammalian cells and showed characteristic intracellular localization, in that hydrophobic HPAAs aggregated strongly and caused high cytotoxicity in proportion to their hydrophobicity. In the present study, we investigated the cytotoxicity of these aggregate-prone hydrophobic HPAAs, assuming that the ubiquitin proteasome system is impaired in the same manner as other well-known aggregate-prone polyglutamine-containing proteins. Some highly hydrophobic HPAAs caused a deficiency in the ubiquitin proteasome system and excess endoplasmic reticulum stress, leading to apoptosis. These results indicate that the property of causing excess endoplasmic reticulum stress by proteasome impairment may contribute to the strong cytotoxicity of highly hydrophobic HPAAs, and proteasome impairment and the resulting excess endoplasmic reticulum stress is not a common cytotoxic effect of aggregate-prone proteins such as polyglutamine.
Comparative Analysis of Decision Trees with Logistic Regression in Predicting Fault-Prone Classes
NASA Astrophysics Data System (ADS)
Singh, Yogesh; Takkar, Arvinder Kaur; Malhotra, Ruchika
There are available metrics for predicting fault prone classes, which may help software organizations for planning and performing testing activities. This may be possible due to proper allocation of resources on fault prone parts of the design and code of the software. Hence, importance and usefulness of such metrics is understandable, but empirical validation of these metrics is always a great challenge. Decision Tree (DT) methods have been successfully applied for solving classification problems in many applications. This paper evaluates the capability of three DT methods and compares its performance with statistical method in predicting fault prone software classes using publicly available NASA data set. The results indicate that the prediction performance of DT is generally better than statistical model. However, similar types of studies are required to be carried out in order to establish the acceptability of the DT models.
Deep vein thrombosis after spine operation in prone position with subclavian venous catheterization: a case report.
Cho, Jae Kyung; Han, Jin Hee; Park, Sung Wook; Kim, Keon Sik
We experienced a case of deep vein thrombosis after spine surgery in the prone position with a central venous catheter (CVC). Posterior lumbar interbody fusion was performed on a 73-year-old female patient who was diagnosed with spinal stenosis. Accordingly, in the operation room under general anesthesia, two-lumen CVC were inserted into the left subclavian vein. The surgery was performed in the prone position with a Wilson frame. On the next day, there was a sudden occurrence of severe edema in the patient's left arm. By ultrasonography and computed tomography scanning, extensive deep vein thrombosis was observed in the left subclavian vein. The existence of a factor affecting blood flow such as the prone position may increase the risk of thrombus formation. Therefore, careful perioperative evaluation should be implemented.
Suicide proneness in college students: relationships with gender, procrastination, and achievement motivation.
Klibert, Jeffrey; Langhinrichsen-Rohling, Jennifer; Luna, Amy; Robichaux, Michelle
This study examined the relationships between 2 academic dispositions (i.e., procrastination and achievement motivation) and 2 indices of suicidal proneness in college women and men. The degree these 2 academic dispositions could predict unique variance in suicide proneness scores, above and beyond the influence of depression and self-esteem was also examined for each gender. Participants included 475 (336 women, 139 men) undergraduates from a southeastern university. For both genders, procrastination and achievement motivation were significantly correlated at the univarate level with the suicide proneness indices. However, for college women, but not men, procrastination significantly accounted for unique amounts of variance in both suicide indices above and beyond the influence of depression and self-esteem. Implications for suicide intervention efforts directed toward college women and men are offered.
Registration of prone and supine colons in the presence of topological changes
NASA Astrophysics Data System (ADS)
Suh, Jung W.; Wyatt, Christopher L.
CT colonography is a minimally-invasive screening technique for colorectal polyps in which X-ray CT images of the distended colon are acquired, usually in the prone and supine positions. Registration of segmented colons from both images will be useful for computer-assisted polyp detection. We have previously presented algorithms for registration of the prone and supine colon when both are well distended and there is a single connected lumen. However due to inadequate bowel preparation or peristalsis there may be collapsed segments in one or both of the colons resulting in a topological change in the images. Such changes make deformable registrations of the colons difficult, and at present there are no registration algorithms which can accommodate them. In this paper we present an algorithm which can perform volume registration of prone/supine colon images in the presence of a topological change.
Speech Errors, Error Correction, and the Construction of Discourse.
ERIC Educational Resources Information Center
Linde, Charlotte
Speech errors have been used in the construction of production models of the phonological and semantic components of language, and for a model of interactional processes. Errors also provide insight into how speakers plan discourse and syntactic structure,. Different types of discourse exhibit different types of error. The present data are taken…
Otitis-Prone Children Produce Functional Antibodies to Pneumolysin and Pneumococcal Polysaccharides
Wiertsema, Selma P.; Corscadden, Karli J.; Mateus, Tulia; Mullaney, Gemma L.; Zhang, Guicheng; Richmond, Peter C.; Thornton, Ruth B.
ABSTRACT The pneumococcus is a major otitis media (OM) pathogen, but data are conflicting regarding whether otitis-prone children have impaired humoral immunity to pneumococcal antigens. We and others have shown that otitis-prone and healthy children have similar antibody titers to pneumococcal proteins and polysaccharides (vaccine and nonvaccine types); however, the quality of antibodies from otitis-prone children has not been investigated. Antibody function, rather than titer, is considered to be a better correlate of protection from pneumococcal disease. Therefore, we compared the capacities of antibodies from otitis-prone (cases) and healthy (controls) children to neutralize pneumolysin, the pneumococcal toxin currently in development as a vaccine antigen, and to opsonize pneumococcal vaccine and nonvaccine serotypes. A pneumolysin neutralization assay was conducted on cholesterol-depleted complement-inactivated sera from 165 cases and 61 controls. A multiplex opsonophagocytosis assay (MOPA) was conducted on sera from 20 cases and 20 controls. Neutralizing and opsonizing titers were calculated with antigen-specific IgG titers to determine antibody potency for pneumolysin, pneumococcal conjugate vaccine (PCV) polysaccharides, and non-PCV polysaccharides. There was no significant difference in antibody potencies between cases and controls for the antigens tested. Antipneumolysin neutralizing titers increased with the number of episodes of acute OM, but antibody potency did not. Pneumolysin antibody potency was lower in children colonized with pneumococci than in noncarriers, and this was significant for the otitis-prone group (P < 0.05). The production of functional antipneumococcal antibodies in otitis-prone children demonstrates that they respond to the current PCV and are likely to respond to pneumolysin-based vaccines as effectively as healthy children. PMID:28031178
Protective effect of prone posture against hypergravity-induced arterial hypoxaemia in humans.
Rohdin, M; Petersson, J; Mure, M; Glenny, R W; Lindahl, S G E; Linnarsson, D
Patients with acute respiratory distress syndrome have increased lung tissue weight and therefore an increased hydrostatic pressure gradient down the lung. Also, they have a better arterial oxygenation in prone (face down) than in supine (face up) posture. We hypothesized that this effect of the direction of gravity also existed in healthy humans, when increased hydrostatic gradients were induced by hypergravity. Ten healthy subjects were studied in a human centrifuge while exposed to 1 or 5 G in anterio-posterior (supine) or posterio-anterior (prone) direction. We measured blood gases using remote-controlled sampling and gas exchange by mass spectrometry. Hypergravity led to marked impairments of arterial oxygenation in both postures and more so in supine posture. At 5 G, the arterial oxygen saturation was 84.6 +/- 1.2 % (mean +/- S.E.M.) in supine and 89.7 +/- 1.4 % in prone posture (P < 0.001 for supine vs. prone). Ventilation and alveolar PO2 were increased at 5 G and did not differ between postures. The alveolar-to-arterial PO2 difference increased at 5 G to 8.0 +/- 0.2 kPa and 6.6 +/- 0.3 kPa in supine and prone postures (P = 0.003). Arterial oxygenation was less impaired in prone during hypergravity due to a better-preserved alveolo-arterial oxygen transport. We speculate that mammals have developed a cardiopulmonary structure that favours function with the gravitational vector in the posterio-anterior direction.
Trilisky, Igor; Ward, Emily; Dachman, Abraham H
CT colonography (CTC) is a colorectal cancer screening modality which is becoming more widely implemented and has shown polyp detection rates comparable to those of optical colonoscopy. CTC has the potential to improve population screening rates due to its minimal invasiveness, no sedation requirement, potential for reduced cathartic examination, faster patient throughput, and cost-effectiveness. Proper implementation of a CTC screening program requires careful attention to numerous factors, including patient preparation prior to the examination, the technical aspects of image acquisition, and post-processing of the acquired data. A CTC workstation with dedicated software is required with integrated CTC-specific display features. Many workstations include computer-aided detection software which is designed to decrease errors of detection by detecting and displaying polyp-candidates to the reader for evaluation. There are several pitfalls which may result in false-negative and false-positive reader interpretation. We present an overview of the potential errors in CTC and a systematic approach to avoid them.
Lionakis, M.S.; Hajishengallis, G.
In recent years, the study of genetic defects arising from inborn errors in immunity has resulted in the discovery of new genes involved in the function of the immune system and in the elucidation of the roles of known genes whose importance was previously unappreciated. With the recent explosion in the field of genomics and the increasing number of genetic defects identified, the study of naturally occurring mutations has become a powerful tool for gaining mechanistic insight into the functions of the human immune system. In this concise perspective, we discuss emerging evidence that inborn errors in immunity constitute real-life models that are indispensable both for the in-depth understanding of human biology and for obtaining critical insights into common diseases, such as those affecting oral health. In the field of oral mucosal immunity, through the study of patients with select gene disruptions, the interleukin-17 (IL-17) pathway has emerged as a critical element in oral immune surveillance and susceptibility to inflammatory disease, with disruptions in the IL-17 axis now strongly linked to mucosal fungal susceptibility, whereas overactivation of the same pathways is linked to inflammatory periodontitis. PMID:25900229
Predicting Fault Prone Modules by the Dempster-Shafer Belief Networks
Guo, Lan; Cukic, Bojan; Singh, Harshinder
This paper describes a novel methodology for predicting fault prone modules. The methodology is based on Dempster-Shafer (D-S) belief networks. Our approach consists of three steps: First, building the Dempster-Shafer network by the induction algorithm; Second, selecting the predictors (attributes) by the logistic procedure; Third, feeding the predictors describing the modules of the current project into the inducted Dempster-Shafer network and identifying fault prone modules. We applied this methodology to a NASA dataset. The prediction accuracy of our methodology is higher than that achieved by logistic regression or discriminant analysis on the same dataset. PMID:26120284
[Ventilation in prone decubitus in a patient with respiratory distress during heart surgery].
Rama-Maceiras, P; Duro, J; Figueira-Moure, A; Rey-Rilo, T; Toral, A; Rodríguez-Rodríguez, A
Acute respiratory failure and adult respiratory distress syndrome are serious complications after heart surgery and are associated with a high mortality rate. We report the case of a 50-year-old man who developed severe respiratory distress after heart surgery with extracorporeal circulation and for whom oxygenation was possible with ventilation in prone decubitus position only after other therapeutic measured had failed. The physiological bases of ventilation in prone decubitus position, as well as the indications and contraindications of the technique are discussed. Early treatment, which is fundamental for managing these patients, facilitates a favorable outcome as is illustrated by the case we report.
Error Analysis in Mathematics Education.
ERIC Educational Resources Information Center
Rittner, Max
The article reviews the development of mathematics error analysis as a means of diagnosing students' cognitive reasoning. Errors specific to addition, subtraction, multiplication, and division are described, and suggestions for remediation are provided. (CL)
Skylab water balance error analysis
NASA Technical Reports Server (NTRS)
Leonard, J. I.
Estimates of the precision of the net water balance were obtained for the entire Skylab preflight and inflight phases as well as for the first two weeks of flight. Quantitative estimates of both total sampling errors and instrumentation errors were obtained. It was shown that measurement error is minimal in comparison to biological variability and little can be gained from improvement in analytical accuracy. In addition, a propagation of error analysis demonstrated that total water balance error could be accounted for almost entirely by the errors associated with body mass changes. Errors due to interaction between terms in the water balance equation (covariances) represented less than 10% of the total error. Overall, the analysis provides evidence that daily measurements of body water changes obtained from the indirect balance technique are reasonable, precise, and relaible. The method is not biased toward net retention or loss.
Prospective issues for error detection.
Blavier, Adélaïde; Rouy, Emmanuelle; Nyssen, Anne-Sophie; de Keyser, Véronique
From the literature on error detection, the authors select several concepts relating error detection mechanisms and prospective memory features. They emphasize the central role of intention in the classification of the errors into slips/lapses/mistakes, in the error handling process and in the usual distinction between action-based and outcome-based detection. Intention is again a core concept in their investigation of prospective memory theory, where they point out the contribution of intention retrievals, intention persistence and output monitoring in the individual's possibilities for detecting their errors. The involvement of the frontal lobes in prospective memory and in error detection is also analysed. From the chronology of a prospective memory task, the authors finally suggest a model for error detection also accounting for neural mechanisms highlighted by studies on error-related brain activity.
IPTV multicast with peer-assisted lossy error control
NASA Astrophysics Data System (ADS)
Li, Zhi; Zhu, Xiaoqing; Begen, Ali C.; Girod, Bernd
Emerging IPTV technology uses source-specific IP multicast to deliver television programs to end-users. To provide reliable IPTV services over the error-prone DSL access networks, a combination of multicast forward error correction (FEC) and unicast retransmissions is employed to mitigate the impulse noises in DSL links. In existing systems, the retransmission function is provided by the Retransmission Servers sitting at the edge of the core network. In this work, we propose an alternative distributed solution where the burden of packet loss repair is partially shifted to the peer IP set-top boxes. Through Peer-Assisted Repair (PAR) protocol, we demonstrate how the packet repairs can be delivered in a timely, reliable and decentralized manner using the combination of server-peer coordination and redundancy of repairs. We also show that this distributed protocol can be seamlessly integrated with an application-layer source-aware error protection mechanism called forward and retransmitted Systematic Lossy Error Protection (SLEP/SLEPr). Simulations show that this joint PARSLEP/ SLEPr framework not only effectively mitigates the bottleneck experienced by the Retransmission Servers, thus greatly enhancing the scalability of the system, but also efficiently improves the resistance to the impulse noise.
Error Sources in Asteroid Astrometry
NASA Technical Reports Server (NTRS)
Owen, William M., Jr.
Asteroid astrometry, like any other scientific measurement process, is subject to both random and systematic errors, not all of which are under the observer's control. To design an astrometric observing program or to improve an existing one requires knowledge of the various sources of error, how different errors affect one's results, and how various errors may be minimized by careful observation or data reduction techniques.
Error Patterns in Problem Solving.
ERIC Educational Resources Information Center
Babbitt, Beatrice C.
Although many common problem-solving errors within the realm of school mathematics have been previously identified, a compilation of such errors is not readily available within learning disabilities textbooks, mathematics education texts, or teacher's manuals for school mathematics texts. Using data on error frequencies drawn from both the Fourth…
Measurement Error. For Good Measure....
ERIC Educational Resources Information Center
Johnson, Stephen; Dulaney, Chuck; Banks, Karen
No test, however well designed, can measure a student's true achievement because numerous factors interfere with the ability to measure achievement. These factors are sources of measurement error, and the goal in creating tests is to have as little measurement error as possible. Error can result from the test design, factors related to individual…
Uncertainty quantification and error analysis
Higdon, Dave M; Anderson, Mark C; Habib, Salman; Klein, Richard; Berliner, Mark; Covey, Curt; Ghattas, Omar; Graziani, Carlo; Seager, Mark; Sefcik, Joseph; Stark, Philip
UQ studies all sources of error and uncertainty, including: systematic and stochastic measurement error; ignorance; limitations of theoretical models; limitations of numerical representations of those models; limitations on the accuracy and reliability of computations, approximations, and algorithms; and human error. A more precise definition for UQ is suggested below.
Feature Referenced Error Correction Apparatus.
A feature referenced error correction apparatus utilizing the multiple images of the interstage level image format to compensate for positional...images and by the generation of an error correction signal in response to the sub-frame registration errors. (Author)
[Rapid PCR authentication Lonicera japanica].
Jiang, Chao; Hou, Jing-Yi; Huang, Lu-Qi; Yuan, Yuan; Chen, Min; Jin, Yan
To simply and rapid authenticate Lonicera japanica. Rapid allele-specific PCR primer was designed base on trnL-trnF 625 G/T Single nucleotide polymorphism and the PCR reaction systems including annealing temperature was optimized; optimized results were performed to authenticate L. japanica and its 9 adulterants. When 100 x SYBR Green I was added in the PCR product of 87 degrees C initial denatured 1 min; 87 degrees C denatured 5 s, 68 degrees C annealing 5 s, 30 cycle; L. japanica visualize strong green fluorescence under 365 nm UV lamp whereas adulterants without. The results indicate rapid allele-specific PCR could authenticate L. japanica and its adulterants rapidly and simply.
Hamilton, J W
In his overall assessment of parapraxes in 1901, Freud included typographical mistakes but did not elaborate on or study this subject nor did he have anything to say about it in his later writings. This paper lists textual errors from a variety of current literary sources and explores the dynamic importance of their execution and the failure to make necessary corrections during the editorial process. While there has been a deemphasis of the role of unconscious determinants in the genesis of all slips as a result of recent findings in cognitive psychology, the examples offered suggest that, with respect to motivation, lapses in compulsivity contribute to their original commission while thematic compliance and voyeuristic issues are important in their not being discovered prior to publication.
Rapid mapping of volumetric errors
Krulewich, D.; Hale, L.; Yordy, D.
This paper describes a relatively inexpensive, fast, and easy to execute approach to mapping the volumetric errors of a machine tool, coordinate measuring machine, or robot. An error map is used to characterize a machine or to improve its accuracy by compensating for the systematic errors. The method consists of three steps: (1) modeling the relationship between the volumetric error and the current state of the machine; (2) acquiring error data based on length measurements throughout the work volume; and (3) optimizing the model to the particular machine.
Register file soft error recovery
Fleischer, Bruce M.; Fox, Thomas W.; Wait, Charles D.; Muff, Adam J.; Watson, III, Alfred T.
Register file soft error recovery including a system that includes a first register file and a second register file that mirrors the first register file. The system also includes an arithmetic pipeline for receiving data read from the first register file, and error detection circuitry to detect whether the data read from the first register file includes corrupted data. The system further includes error recovery circuitry to insert an error recovery instruction into the arithmetic pipeline in response to detecting the corrupted data. The inserted error recovery instruction replaces the corrupted data in the first register file with a copy of the data from the second register file.
Supine or prone position for mini-PNL procedure: does it matter.
Tokatlı, Zafer; Gokce, Mehmet Ilker; Süer, Evren; Sağlam, Remzi
In this study it is aimed to compare the success and complication rates of mini-PNL procedure in supine and prone positions. In this retrospective study data of 180 patients treated with MPNL either in supine (n = 54) or prone (n = 126) positions between May 2009 and August 2014 was investigated. Success was defined as no visible stones >2 mm. Perioperative complications were classified using the modified Clavien system. Groups were compared with Chi square test or Student t test and for statistical significance p value of 0.05 was accepted. Mean age of the population was 42.5 ± 8.2 years and mean stone size was 23.9 ± 4.1 mm. The two groups were similar with regard to demographic characteristics and stone related characteristics except the ASA status. Success rates of the supine and prone groups were 85.1 and 87.3%, respectively (p = 0.701). No statistically significant differences in terms of complications were observed. Mean operative time was the only parameter different between the two groups (55 vs 82 min, p = 0.001). Supine position for PNL seems to be promising and the complication and success rates are shown to be similar to the prone position with MPNL technique. The only significant benefit of this technique is shorter operative time.
Change in trunk muscle activities with prone bridge exercise in patients with chronic low back pain
Kong, Yong-soo; Park, Seol; Kweon, Mi-Gyong; Park, Ji-won
[Purpose] The aim of this study was to determine the effect of three different bridge exercises on internal oblique, external oblique, transverse abdominis, and erector spinae activities. [Subjects and Methods] Forty-five subjects with chronic low back pain participated in this study. The training outcome was evaluated with three different testing methods: supine bridge exercise, supine bridge on Swiss ball exercise, and prone bridge exercise. The activities of the transverse abdominis, internal oblique, external oblique, and erector spinae were measured using surface electromyography. [Results] There were significant differences in the internal oblique, external oblique, and erector spinae according to the three kinds of bridging exercises. The internal oblique, external oblique and transverse abdominis activities were highest in the prone bridge exercise, followed by those in the supine bridge on Swiss ball exercise, and supine bridge exercises. The activity of erector spine was highest in the supine bridge on Swiss ball exercise followed by the supine bridge exercise and prone bridge exercise. [Conclusion] These results suggest that prone bridge exercise is more effective than conventional supine bridge exercise and supine bridge on Swiss ball in increasing trunk muscle activity of chronic low back pain patients. PMID:26957771
44 CFR 60.3 - Flood plain management criteria for flood-prone areas.
Code of Federal Regulations, 2011 CFR
... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Flood plain management criteria for flood-prone areas. 60.3 Section 60.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood...
44 CFR 60.3 - Flood plain management criteria for flood-prone areas.
Code of Federal Regulations, 2014 CFR
... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Flood plain management criteria for flood-prone areas. 60.3 Section 60.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood...
44 CFR 60.3 - Flood plain management criteria for flood-prone areas.
Code of Federal Regulations, 2010 CFR
... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plain management criteria for flood-prone areas. 60.3 Section 60.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood...
44 CFR 60.24 - Planning considerations for flood-related erosion-prone areas.
Code of Federal Regulations, 2012 CFR
... flood-related erosion-prone areas. 60.24 Section 60.24 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing...
44 CFR 60.24 - Planning considerations for flood-related erosion-prone areas.
Code of Federal Regulations, 2014 CFR
... flood-related erosion-prone areas. 60.24 Section 60.24 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing...
44 CFR 60.24 - Planning considerations for flood-related erosion-prone areas.
Code of Federal Regulations, 2010 CFR
... flood-related erosion-prone areas. 60.24 Section 60.24 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing...
44 CFR 60.24 - Planning considerations for flood-related erosion-prone areas.
Code of Federal Regulations, 2013 CFR
... flood-related erosion-prone areas. 60.24 Section 60.24 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing...
44 CFR 60.3 - Flood plain management criteria for flood-prone areas.
Code of Federal Regulations, 2012 CFR
... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Flood plain management criteria for flood-prone areas. 60.3 Section 60.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood...
44 CFR 60.24 - Planning considerations for flood-related erosion-prone areas.
Code of Federal Regulations, 2011 CFR
... flood-related erosion-prone areas. 60.24 Section 60.24 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Additional Considerations in Managing...
44 CFR 60.3 - Flood plain management criteria for flood-prone areas.
Code of Federal Regulations, 2013 CFR
... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Flood plain management criteria for flood-prone areas. 60.3 Section 60.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood...
A Modified Obesity Proneness Model Predicts Adolescent Weight Concerns and Inability to Self-Regulate Eating
ERIC Educational Resources Information Center
Nickelson, Jen; Bryant, Carol A.; McDermott, Robert J.; Buhi, Eric R.; DeBate, Rita D.
Background: The prevalence of obesity among high school students has risen in recent decades. Many high school students report trying to lose weight and some engage in disordered eating to do so. The obesity proneness model suggests that parents may influence their offspring's development of disordered eating. This study examined the viability of…
Binge eating proneness emerges during puberty in female rats: a longitudinal study.
Klump, Kelly L; Suisman, Jessica L; Culbert, Kristen M; Kashy, Deborah A; Sisk, Cheryl L
Puberty is a critical risk period for binge eating and eating disorders characterized by binge eating. Previous research focused almost entirely on psychosocial risk factors during puberty to the relative exclusion of biological influences. The current study addressed this gap by examining the emergence of binge eating during puberty in a rat model. We predicted that there would be minimal differences in binge eating proneness during pre-early puberty, but significant differences would emerge during puberty. Two independent samples of female Sprague-Dawley rats (n = 30 and n = 36) were followed longitudinally across pre-early puberty, mid-late puberty, and adulthood. Binge eating proneness was defined using the binge eating resistant (BER)/binge eating prone (BEP) model of binge eating that identifies BER and BEP rats in adulthood. Across two samples of rats, binge eating proneness emerged during puberty. Mixed linear models showed little difference in palatable food intake between BER and BEP rats during pre-early puberty, but significant group differences emerged during mid-late puberty and adulthood. Group differences could not be accounted for by changes in nonpalatable food intake or body weight. Similar to patterns in humans, individual differences in binge eating emerge during puberty in female rats. These findings provide strong confirming evidence for the importance of biological risk factors in developmental trajectories of binge eating risk across adolescence.
"Deviance Proneness" and Adolescent Smoking 1980 versus 2001: Has There Been a "Hardening" of Adolescent Smoking?
ERIC Educational Resources Information Center
Chassin, Laurie; Presson, Clark; Morgan-Lopez, Antonio; Sherman, Steven J.
In a midwestern community sample, we tested for evidence of "hardening" of adolescent cigarette smoking between 1980 and 2001 by comparing adolescent smokers and nonsmokers at these two times on measures indicative of "deviance proneness" in Jessor and Jessor's [Jessor, R., & Jessor, S. L. (1977). "Problem behavior and psychosocial development: A…
Shame and Guilt-Proneness in Adolescents: Gene-Environment Interactions
Szentágotai-Tătar, Aurora; Chiș, Adina; Vulturar, Romana; Dobrean, Anca; Cândea, Diana Mirela; Miu, Andrei C.
Rooted in people's preoccupation with how they are perceived and evaluated, shame and guilt are self-conscious emotions that play adaptive roles in social behavior, but can also contribute to psychopathology when dysregulated. Shame and guilt-proneness develop during childhood and adolescence, and are influenced by genetic and environmental factors that are little known to date. This study investigated the effects of early traumatic events and functional polymorphisms in the brain-derived neurotrophic factor (BDNF) gene and the serotonin transporter gene promoter (5-HTTLPR) on shame and guilt in adolescents. A sample of N = 271 healthy adolescents between 14 and 17 years of age filled in measures of early traumatic events and proneness to shame and guilt, and were genotyped for the BDNF Val66Met and 5-HTTLPR polymorphisms. Results of moderator analyses indicated that trauma intensity was positively associated with guilt-proneness only in carriers of the low-expressing Met allele of BDNF Val66Met. This is the first study that identifies a gene-environment interaction that significantly contributes to guilt proneness in adolescents, with potential implications for developmental psychopathology. PMID:26230319
Do Guilt- and Shame-Proneness Differentially Predict Prosocial, Aggressive, and Withdrawn Behaviors during Early Adolescence?
ERIC Educational Resources Information Center
Roos, Sanna; Hodges, Ernest V. E.; Salmivalli, Christina
In this short-term longitudinal study, we systematically examined the distinctiveness of guilt- and shame-proneness in early adolescents (N = 395, mean age = 11.8 years) in terms of differential relations with peer reported prosocial behavior, withdrawal, and aggression. Results from structural equation modeling indicated that guilt-proneness…
The Coronary-Prone Behavior Pattern and Trait Anxiety: Evidence for Discriminant Validity.
ERIC Educational Resources Information Center
Nielson, Warren R.; Dobson, Keith S.
Supports the discriminant validity of the Coronary-Prone Behavior Pattern, as assessed by the Jenkins Activity Survey, in relation to trait anxiety. Future research should include measures of trait anxiety to collaborate findings in a laboratory setting. (Author/JAC)
Female Coronary-Prone Behaviors: Relationship to Alpha and Self-Concept.
ERIC Educational Resources Information Center
Comer, David W.; And Others
Researchers have been working toward isolating a set of psychological risk factors that would reliably predict coronary problems. This coronary-prone behavior pattern, Type A, is characterized by extremes of competitiveness, striving for achievement, impatience, and hostility. Differences were examined between 20 Type A and 20 Type B…
44 CFR 60.23 - Planning considerations for mudslide (i.e., mudflow)-prone areas.
Code of Federal Regulations, 2010 CFR
... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Planning considerations for mudslide (i.e., mudflow)-prone areas. 60.23 Section 60.23 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National...
[Methodic approaches to determining the level of occupational fitness in jobs prone to trauma].
Iushkova, O I; Matiukhin, V V; Poroshenko, A S; Iampol'skaia, E G
The article deals with main methods to evaluate functional state of various body systems and with the methods-based criteria of occupational fitness for miscellaneous activities. Examination of 11 types of jobs prone to trauma helped to specify integral parameter for occupational selection.
Towards error-free interaction.
Tsoneva, Tsvetomira; Bieger, Jordi; Garcia-Molina, Gary
Human-machine interaction (HMI) relies on pat- tern recognition algorithms that are not perfect. To improve the performance and usability of these systems we can utilize the neural mechanisms in the human brain dealing with error awareness. This study aims at designing a practical error detection algorithm using electroencephalogram signals that can be integrated in an HMI system. Thus, real-time operation, customization, and operation convenience are important. We address these requirements in an experimental framework simulating machine errors. Our results confirm the presence of brain potentials related to processing of machine errors. These are used to implement an error detection algorithm emphasizing the differences in error processing on a per subject basis. The proposed algorithm uses the individual best bipolar combination of electrode sites and requires short calibration. The single-trial error detection performance on six subjects, characterized by the area under the ROC curve ranges from 0.75 to 0.98.
Standard Deviation and Intra Prediction Mode Based Adaptive Spatial Error Concealment (SEC) in H.264/AVC
NASA Astrophysics Data System (ADS)
Wang, Jun; Wang, Lei; Ikenaga, Takeshi; Goto, Satoshi
Transmission of compressed video over error prone channels may result in packet losses or errors, which can significantly degrade the image quality. Therefore an error concealment scheme is applied at the video receiver side to mask the damaged video. Considering there are 3 types of MBs (Macro Blocks) in natural video frame, i. e., Textural MB, Edged MB, and Smooth MB, this paper proposes an adaptive spatial error concealment which can choose 3 different methods for these 3 different MBs. For criteria of choosing appropriate method, 2 factors are taken into consideration. Firstly, standard deviation of our proposed edge statistical model is exploited. Secondly, some new features of latest video compression standard H.264/AVC, i. e., intra prediction mode is also considered for criterion formulation. Compared with previous works, which are only based on deterministic measurement, proposed method achieves the best image recovery. Subjective and objective image quality evaluations in experiments confirmed this.
Is the supine position superior to the prone position for percutaneous nephrolithotomy (PCNL)?
Zhang, Xiaohua; Xia, Leilei; Xu, Tianyuan; Wang, Xianjin; Zhong, Shan; Shen, Zhoujun
The objective of this study is to update the two previous meta-analyses in order to evaluate the efficacy and safety of percutaneous nephrolithotomy (PCNL) for patients in the prone position versus supine position. An electronic database search of MEDLINE, EMBASE, google scholar, and the Cochrane library was performed up to June, 2013. All studies comparing prone with supine position for PCNL were included. The outcome measures were stone-free rate, operative time, complication and hospital stay. Two randomized controlled trials (RCTs) and 7 non-RCTs, including 6,413 patients (4,956 patients in the prone position group and 1,457 patients in the supine position group), met the inclusion criteria. Meta-analysis of extractable data showed that PCNL in the supine position was associated with a significantly shorter operative time (WMD: 21.7; 95% CI 2.46-40.94; p = 0.03) but lower stone-free rate (OR: 1.36; 95% CI 1.19-1.56; p < 0.0001) than PCNL in the prone position. There was no difference between the two positions regarding hospital stay (WMD = 0.05; 95% CI -0.16-0.25; p = 0.66) and complication rate (OR: 1.1; 95% CI 0.94-1.28; p = 0.24). In conclusion, the present study found different results from the two previous meta-analyses results regarding stone-free rate; PCNL in the supine position had a significantly lower stone-free rate than that in prone position.
Improved Error Thresholds for Measurement-Free Error Correction
NASA Astrophysics Data System (ADS)
Crow, Daniel; Joynt, Robert; Saffman, M.
Motivated by limitations and capabilities of neutral atom qubits, we examine whether measurement-free error correction can produce practical error thresholds. We show that this can be achieved by extracting redundant syndrome information, giving our procedure extra fault tolerance and eliminating the need for ancilla verification. The procedure is particularly favorable when multiqubit gates are available for the correction step. Simulations of the bit-flip, Bacon-Shor, and Steane codes indicate that coherent error correction can produce threshold error rates that are on the order of 10-3 to 10-4—comparable with or better than measurement-based values, and much better than previous results for other coherent error correction schemes. This indicates that coherent error correction is worthy of serious consideration for achieving protected logical qubits.
Improved Error Thresholds for Measurement-Free Error Correction.
Crow, Daniel; Joynt, Robert; Saffman, M
Motivated by limitations and capabilities of neutral atom qubits, we examine whether measurement-free error correction can produce practical error thresholds. We show that this can be achieved by extracting redundant syndrome information, giving our procedure extra fault tolerance and eliminating the need for ancilla verification. The procedure is particularly favorable when multiqubit gates are available for the correction step. Simulations of the bit-flip, Bacon-Shor, and Steane codes indicate that coherent error correction can produce threshold error rates that are on the order of 10^{-3} to 10^{-4}-comparable with or better than measurement-based values, and much better than previous results for other coherent error correction schemes. This indicates that coherent error correction is worthy of serious consideration for achieving protected logical qubits.
Medication safety in neonatal care: a review of medication errors among neonates
Krzyzaniak, Natalia; Bajorek, Beata
Objective: The objective of this study was to describe the medication errors in hospitalized patients, comparing those in neonates with medication errors across the age spectrum. Method: In tier 1, PubMed, Embase and Google Scholar were searched, using selected MeSH terms relating to hospitalized paediatric, adult and elderly populations. Tier 2 involved a search of the same electronic databases for literature relating to hospitalized neonatal patients. Results: A total of 58 articles were reviewed. Medication errors were well documented in each patient group. Overall, prescribing and administration errors were most commonly identified across each population, and mostly related to errors in dosing. Errors due to patient misidentification and overdosing were particularly prevalent in neonates, with 47% of administration errors involving at least tenfold overdoses. Unique errors were identified in elderly patients, comprising duplication of therapy and unnecessary prescribing of medicines. Overall, the medicines most frequently identified with error across each patient group included: heparin, antibiotics, insulin, morphine and parenteral nutrition. While neonatal patients experience the same types of medication errors as other hospitalized patients, the medication-use process within this group is more complex and has greater consequences resulting from error. Suggested strategies to help overcome medication error most commonly involved the integration of a clinical pharmacist into the treating team. Conclusion: This review highlights that each step of the medication-use process is prone to error across the age spectrum. Further research is required to develop targeted strategies relevant to specific patient groups that integrate key pharmacy services into wards. PMID:27298721
NASA Technical Reports Server (NTRS)
Merceret, Francis; Lane, John; Immer, Christopher; Case, Jonathan; Manobianco, John
The contour error map (CEM) algorithm and the software that implements the algorithm are means of quantifying correlations between sets of time-varying data that are binarized and registered on spatial grids. The present version of the software is intended for use in evaluating numerical weather forecasts against observational sea-breeze data. In cases in which observational data come from off-grid stations, it is necessary to preprocess the observational data to transform them into gridded data. First, the wind direction is gridded and binarized so that D(i,j;n) is the input to CEM based on forecast data and d(i,j;n) is the input to CEM based on gridded observational data. Here, i and j are spatial indices representing 1.25-km intervals along the west-to-east and south-to-north directions, respectively; and n is a time index representing 5-minute intervals. A binary value of D or d = 0 corresponds to an offshore wind, whereas a value of D or d = 1 corresponds to an onshore wind. CEM includes two notable subalgorithms: One identifies and verifies sea-breeze boundaries; the other, which can be invoked optionally, performs an image-erosion function for the purpose of attempting to eliminate river-breeze contributions in the wind fields.
Comparison of analytical error and sampling error for contaminated soil.
Gustavsson, Björn; Luthbom, Karin; Lagerkvist, Anders
Investigation of soil from contaminated sites requires several sample handling steps that, most likely, will induce uncertainties in the sample. The theory of sampling describes seven sampling errors that can be calculated, estimated or discussed in order to get an idea of the size of the sampling uncertainties. With the aim of comparing the size of the analytical error to the total sampling error, these seven errors were applied, estimated and discussed, to a case study of a contaminated site. The manageable errors were summarized, showing a range of three orders of magnitudes between the examples. The comparisons show that the quotient between the total sampling error and the analytical error is larger than 20 in most calculation examples. Exceptions were samples taken in hot spots, where some components of the total sampling error get small and the analytical error gets large in comparison. Low concentration of contaminant, small extracted sample size and large particles in the sample contribute to the extent of uncertainty.
Droplet-based micro oscillating-flow PCR chip
NASA Astrophysics Data System (ADS)
Wang, Wei; Li, Zhi-Xin; Luo, Rong; Lü, Shu-Hai; Xu, Ai-Dong; Yang, Yong-Jun
Polymerase chain reactions (PCR), thermally activated chemical reactions which are widely used for nucleic acid amplification, have recently received much attention in microelectromechanical systems and micro total analysis systems because a wide variety of DNA/RNA molecules can be enriched by PCR for further analyses. In the present work, a droplet-based micro oscillating-flow PCR chip was designed and fabricated by the silicon microfabrication technique. Three different temperature zones, which were stable at denaturation, extension and annealing temperatures and isolated from each other by a thin-wall linkage, were integrated with a single, simple and straight microchannel to form the chip's basic functional structure. The PCR mixture was injected into the chip as a single droplet and flowed through the three temperature zones in the main microchannel in an oscillating manner to achieve the temperature maintenance and transitions. The chip's thermal performance was theoretically analyzed and numerically simulated. The results indicated that the time needed for the temperature of the droplet to change to the target value is less than 1 s, and the root mean square error of temperature is less than 0.2 °C. A droplet of 1 µl PCR mixture with standard HPV (Human Papilloma Virus)-DNA sample inside was amplified by the present chip and the results were analyzed by slab gel electrophoresis with separation of DNA markers in parallel. The electrophoresis results demonstrated that the micro oscillating-flow PCR chip successfully amplified the HPV-DNA, with a processing time of about 15 min which is significantly reduced compared to that for the conventional PCR instrument.
Differences in innate immune response gene regulation in the middle ear of children who are otitis prone and in those not otitis prone
Casey, Janet; Pichichero, Michael
Objective: Acute otitis media (AOM) causes an inflammatory response in the middle ear. We assessed differences in innate immune responses involved in bacterial defense at onset of AOM in children who were stringently defined as otitis prone (sOP) and children not otitis prone (NOP). Study Design: Innate immune genes analysis from middle ear fluid (MEF) samples of children. Methods: Genes of toll-like receptors (TLR), nod-like and retinoic acid-inducible gene-I-like receptors, downstream effectors important for inflammation and apoptosis, including cytokines and chemokines, were studied from MEF samples by using a real-time polymerase chain reaction array. Protein levels of differentially regulated genes were measured by Luminex. Results: Gene expression in MEF among children who were sOP was significantly different in upregulation of interleukin 8, secretory leukocyte peptidase inhibitor, and chemokine (C-C motif) ligand 3, and in downregulation of interferon regulatory factor 7 and its related signaling molecules interferon alpha, Toll-like receptor adaptor molecule 2, chemokine (C-C motif) ligand 5, and mitogen-activated protein kinase 8 compared with children who were NOP. Differences in innate gene regulation were similar when AOM was caused by Streptococcus pneumoniae or nontypeable Haemophilus influenzae. Conclusion: Innate-immune response genes are differentially regulated in children who were sOP compared with children with NOP. PMID:28124644
Evaluation of the anatomical parameters for normal tissue sparing in the prone position radiotherapy with small sized left breasts
Kim, Hyunjung; Kim, Jinyoung
Prone position radiotherapy for a small (< 750 cm3) breast is controversial because of the variable benefits for the irradiated heart volume. The objective anatomical parameters related with chest wall shape that can determine the heart dose sparing patients in the prone position. Twenty-one patients underwent CT-simulation in supine and prone position. Dose volume parameters were compared and the objective indexes such as the Haller index, anthropometric index, mid-sternum thickness, and central lung distance (CLD) were evaluated the relationship between the shape of the chest wall and irradiated normal tissue volume in prone position. The median breast volume was 440.10 cm3 (range, 151.5–727.41 cm3). There was no difference of breast target volume between supine and prone position (p = 0.178). The Haller index under 2.5 (p = 0.046), an anthropometric index over 0.05 (p = 0.007), and the CLD over 2 (p = 0.023) conferred a greater heart sparing effect in the prone position. In conclusions, the objective anatomical parameters related chest wall shape predict the decrease in irradiated heart volume in the prone position. Therefore, it is possible to screen for patients with a reduced heart volume irradiation among those with small breasts before applying prone position radiotherapy. PMID:27756882
77 FR 41881 - Safety Advisory 2012-03; Buckling-Prone Conditions in Continuous Welded Rail Track
Federal Register 2010, 2011, 2012, 2013, 2014
... Federal Railroad Administration Safety Advisory 2012-03; Buckling-Prone Conditions in Continuous Welded... identify buckling-prone conditions. In an effort to heighten awareness of the potential consequences of an... railroads to be caused by the rail buckling under extreme heat conditions (commonly referred to as...
Dopamine reward prediction error coding.
Schultz, Wolfram
Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.
Dopamine reward prediction error coding
Schultz, Wolfram
Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards—an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware. PMID:27069377
Processor register error correction management
Bose, Pradip; Cher, Chen-Yong; Gupta, Meeta S.
Processor register protection management is disclosed. In embodiments, a method of processor register protection management can include determining a sensitive logical register for executable code generated by a compiler, generating an error-correction table identifying the sensitive logical register, and storing the error-correction table in a memory accessible by a processor. The processor can be configured to generate a duplicate register of the sensitive logical register identified by the error-correction table.
Maternal milk, but not formula, regulates the immune response to beta-lactoglobulin in allergy-prone rat pups.
Tooley, Katie L; El-Merhibi, Adaweyah; Cummins, Adrian G; Grose, Randall H; Lymn, Kerry A; DeNichilo, Mark; Penttila, Irmeli A
Controversy exists regarding the timing of the introduction of allergic foods into the diet. We investigated the immune response of rat pups exposed to beta-lactoglobulin (BLG), one of the main allergenic proteins in cow milk. Brown Norway allergy-prone rats were allocated into groups: dam-reared and unchallenged (DR), DR challenged with BLG via gavage (11 mg/d), or rats fed via gastric cannula a formula containing BLG (11 mg/d). BLG was given from d 4 of life. Rats were killed at d 10, 14, or 21. Sera were assayed for total IgE, BLG-specific IgG1, and rat mucosal mast cell protease II (RMCPII; indicator of mucosal mast cell degranulation). Ileum was assessed for cytokine mRNA. Mesenteric lymph nodes (MLN) were assessed for forkhead boxP3 (Foxp3) and chemokine (C-C motif) receptor 7 (CCR7) expression by real-time PCR and immunostained for Foxp3(+) CD4(+) regulatory cells. Formula feeding compared with dam-rearing with or without oral BLG challenge resulted in significantly greater serum IgE, BLG-specific IgG1, RMCPII, and intestinal mast cells but reduced MLN Foxp3(+) cells, Foxp3, and CCR7 expression and ileal cytokines, interleukin (IL)-4, IL-10, and interferon-gamma (P < 0.05). Importantly, giving BLG in the presence of maternal milk resulted in an immune response profile similar to that of unchallenged DR rats but with greater Foxp3 and CCR7 mRNA expression and CD4(+) Foxp3(+) cells (P < 0.05). We conclude that introducing an allergenic food with breast milk reduces immunological indicators of an allergic response, whereas introduction during formula feeding generates an allergic response.
PCR Inhibition of a Quantitative PCR for Detection of Mycobacterium avium Subspecies Paratuberculosis DNA in Feces: Diagnostic Implications and Potential Solutions
Acharya, Kamal R.; Dhand, Navneet K.; Whittington, Richard J.; Plain, Karren M.
Molecular tests such as polymerase chain reaction (PCR) are increasingly being applied for the diagnosis of Johne's disease, a chronic intestinal infection of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). Feces, as the primary test sample, presents challenges in terms of effective DNA isolation, with potential for PCR inhibition and ultimately for reduced analytical and diagnostic sensitivity. However, limited evidence is available regarding the magnitude and diagnostic implications of PCR inhibition for the detection of MAP in feces. This study aimed to investigate the presence and diagnostic implications of PCR inhibition in a quantitative PCR assay for MAP (High-throughput Johne's test) to investigate the characteristics of samples prone to inhibition and to identify measures that can be taken to overcome this. In a study of fecal samples derived from a high prevalence, endemically infected cattle herd, 19.94% of fecal DNA extracts showed some evidence of inhibition. Relief of inhibition by a five-fold dilution of the DNA extract led to an average increase in quantification of DNA by 3.3-fold that consequently increased test sensitivity of the qPCR from 55 to 80% compared to fecal culture. DNA extracts with higher DNA and protein content had 19.33 and 10.94 times higher odds of showing inhibition, respectively. The results suggest that the current test protocol is sensitive for herd level diagnosis of Johne's disease but that test sensitivity and individual level diagnosis could be enhanced by relief of PCR inhibition, achieved by five-fold dilution of the DNA extract. Furthermore, qualitative and quantitative parameters derived from absorbance measures of DNA extracts could be useful for prediction of inhibitory fecal samples. PMID:28210245
PCR Inhibition of a Quantitative PCR for Detection of Mycobacterium avium Subspecies Paratuberculosis DNA in Feces: Diagnostic Implications and Potential Solutions.
Acharya, Kamal R; Dhand, Navneet K; Whittington, Richard J; Plain, Karren M
Molecular tests such as polymerase chain reaction (PCR) are increasingly being applied for the diagnosis of Johne's disease, a chronic intestinal infection of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). Feces, as the primary test sample, presents challenges in terms of effective DNA isolation, with potential for PCR inhibition and ultimately for reduced analytical and diagnostic sensitivity. However, limited evidence is available regarding the magnitude and diagnostic implications of PCR inhibition for the detection of MAP in feces. This study aimed to investigate the presence and diagnostic implications of PCR inhibition in a quantitative PCR assay for MAP (High-throughput Johne's test) to investigate the characteristics of samples prone to inhibition and to identify measures that can be taken to overcome this. In a study of fecal samples derived from a high prevalence, endemically infected cattle herd, 19.94% of fecal DNA extracts showed some evidence of inhibition. Relief of inhibition by a five-fold dilution of the DNA extract led to an average increase in quantification of DNA by 3.3-fold that consequently increased test sensitivity of the qPCR from 55 to 80% compared to fecal culture. DNA extracts with higher DNA and protein content had 19.33 and 10.94 times higher odds of showing inhibition, respectively. The results suggest that the current test protocol is sensitive for herd level diagnosis of Johne's disease but that test sensitivity and individual level diagnosis could be enhanced by relief of PCR inhibition, achieved by five-fold dilution of the DNA extract. Furthermore, qualitative and quantitative parameters derived from absorbance measures of DNA extracts could be useful for prediction of inhibitory fecal samples.
Mal-Adaptation of Event-Related EEG Responses Preceding Performance Errors
Eichele, Heike; Juvodden, Hilde T.; Ullsperger, Markus; Eichele, Tom
Recent EEG and fMRI evidence suggests that behavioral errors are foreshadowed by systematic changes in brain activity preceding the outcome by seconds. In order to further characterize this type of error precursor activity, we investigated single-trial event-related EEG activity from 70 participants performing a modified Eriksen flanker task, in particular focusing on the trial-by-trial dynamics of a fronto-central independent component that previously has been associated with error and feedback processing. The stimulus-locked peaks in the N2 and P3 latency range in the event-related averages showed expected compatibility and error-related modulations. In addition, a small pre-stimulus negative slow wave was present at erroneous trials. Significant error-preceding activity was found in local stimulus sequences with decreased conflict in the form of less negativity at the N2 latency (310–350 ms) accumulating across five trials before errors; concomitantly response times were speeding across trials. These results illustrate that error-preceding activity in event-related EEG is associated with the performance monitoring system and we conclude that the dynamics of performance monitoring contribute to the generation of error-prone states in addition to the more remote and indirect effects in ongoing activity such as posterior alpha power in EEG and default mode drifts in fMRI. PMID:20740080
Compensating For GPS Ephemeris Error
NASA Technical Reports Server (NTRS)
Wu, Jiun-Tsong
Method of computing position of user station receiving signals from Global Positioning System (GPS) of navigational satellites compensates for most of GPS ephemeris error. Present method enables user station to reduce error in its computed position substantially. User station must have access to two or more reference stations at precisely known positions several hundred kilometers apart and must be in neighborhood of reference stations. Based on fact that when GPS data used to compute baseline between reference station and user station, vector error in computed baseline is proportional ephemeris error and length of baseline.
NASA Technical Reports Server (NTRS)
Mcruer, D. T.; Clement, W. F.; Allen, R. W.
Human error, a significant contributing factor in a very high proportion of civil transport, general aviation, and rotorcraft accidents is investigated. Correction of the sources of human error requires that one attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation operations is presented. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.
Confidence limits and their errors
Rajendran Raja
Confidence limits are common place in physics analysis. Great care must be taken in their calculation and use especially in cases of limited statistics. We introduce the concept of statistical errors of confidence limits and argue that not only should limits be calculated but also their errors in order to represent the results of the analysis to the fullest. We show that comparison of two different limits from two different experiments becomes easier when their errors are also quoted. Use of errors of confidence limits will lead to abatement of the debate on which method is best suited to calculate confidence limits.
Comparison of two real-time PCR assays for the detection of malaria parasites from hemolytic blood samples - Short communication.
Hagen, Ralf Matthias; Hinz, Rebecca; Tannich, Egbert; Frickmann, Hagen
We compared the performance of an in-house and a commercial malaria polymerase chain reaction (PCR) assay using freeze-thawed hemolytic blood samples. A total of 116 freeze-thawed ethylenediamine tetraacetic acid (EDTA) blood samples of patients with suspicion of malaria were analyzed by an in-house as well as by a commercially available real-time PCR. Concordant malaria negative PCR results were reported for 39 samples and malaria-positive PCR results for 67 samples. The in-house assay further detected one case of Plasmodium falciparum infection, which was negative in the commercial assay as well as five cases of P. falciparum malaria and three cases of Plasmodium vivax malaria, which showed sample inhibition in the commercial assay. The commercial malaria assay was positive in spite of a negative in-house PCR result in one case. In all concordant results, cycle threshold values of P. falciparum-positive samples were lower in the commercial PCR than in the in-house assay. Although Ct values of the commercial PCR kit suggest higher sensitivity in case of concordant results, it is prone to inhibition if it is applied to hemolytic freeze-thawed blood samples. The number of misidentifications was, however, identical for both real-time PCR assays.
Measurement Error and Equating Error in Power Analysis
ERIC Educational Resources Information Center
Phillips, Gary W.; Jiang, Tao
Power analysis is a fundamental prerequisite for conducting scientific research. Without power analysis the researcher has no way of knowing whether the sample size is large enough to detect the effect he or she is looking for. This paper demonstrates how psychometric factors such as measurement error and equating error affect the power of…
Correcting numerical integration errors caused by small aliasing errors
Smallwood, D.O.
Small sampling errors can have a large effect on numerically integrated waveforms. An example is the integration of acceleration to compute velocity and displacement waveforms. These large integration errors complicate checking the suitability of the acceleration waveform for reproduction on shakers. For waveforms typically used for shaker reproduction, the errors become significant when the frequency content of the waveform spans a large frequency range. It is shown that these errors are essentially independent of the numerical integration method used, and are caused by small aliasing errors from the frequency components near the Nyquist frequency. A method to repair the integrated waveforms is presented. The method involves using a model of the acceleration error, and fitting this model to the acceleration, velocity, and displacement waveforms to force the waveforms to fit the assumed initial and final values. The correction is then subtracted from the acceleration before integration. The method is effective where the errors are isolated to a small section of the time history. It is shown that the common method to repair these errors using a high pass filter is sometimes ineffective for this class of problem.
Anxiety and Error Monitoring: Increased Error Sensitivity or Altered Expectations?
ERIC Educational Resources Information Center
Compton, Rebecca J.; Carp, Joshua; Chaddock, Laura; Fineman, Stephanie L.; Quandt, Lorna C.; Ratliff, Jeffrey B.
This study tested the prediction that the error-related negativity (ERN), a physiological measure of error monitoring, would be enhanced in anxious individuals, particularly in conditions with threatening cues. Participants made gender judgments about faces whose expressions were either happy, angry, or neutral. Replicating prior studies, midline…
DNA methylation errors in imprinting disorders and assisted reproductive technology.
Chiba, Hatsune; Hiura, Hitoshi; Okae, Hiroaki; Miyauchi, Naoko; Sato, Fumi; Sato, Akiko; Arima, Takahiro
There have been increased incident reports of rare imprinting disorders associated with assisted reproductive technology (ART). ART is an important treatment for infertile people of reproductive age and is increasingly common. The identification of epigenetic changes at imprinted loci in ART infants has led to the suggestion that the techniques themselves may predispose embryos to acquisition of imprinting errors and disease. It is still unknown, however, at what point(s) these imprinting errors arise, or the risk factors. In this review it was hypothesized that the particular steps of the ART process may be prone to induction of imprinting methylation errors during gametogenesis, fertilization and early embryonic development. In addition, imprinting diseases and their causes are explained. Moreover, using a Japanese nationwide epidemiological study of imprinting diseases, their association with ART is determined. Epigenetic studies are required to understand the pathogenesis of this association; the ART-related risk factor(s); and the precautions that can be taken to prevent the occurrence of these syndromes. It is hoped that the constitution of children born after ART will indicate the safest and most ethical approach to use, which will be invaluable for the future development of standard ART treatment.
Aberrant expression of PDGF ligands and receptors in the tumor prone ovary of follitropin receptor knockout (FORKO) mouse.
Chen, Xinlei; Aravindakshan, Jayaprakash; Yang, Yinzhi; Tiwari-Pandey, Rashmi; Sairam, M Ram
Although PDGF family members play a vital role in cell proliferation, motility and chemotaxis via activation of structurally similar alpha- and beta-receptors, little is known of their function in ovarian regulation and induction of tumorigenesis. Microarray analyses of ovaries from young follitropin receptor knockout (FORKO) mice that are prone to late ovarian tumors upon aging have revealed significant imbalances in PDGF ligands and receptors. We hypothesized that FSH/FSH-R signaling may exert effects partly by regulation of PDGF the family. To further understand their implications for ovarian tumorigenesis, we studied FORKO ovaries and hormonal regulation of the PDGF family members in normal mice, by using RT-PCR, Q-PCR, immunohistochemistry and western blotting. While PDGF-C and PDGFR-alpha increased, PDGFR-beta mRNA and protein decreased significantly in absence of FSH-R signaling. In the normal ovary, PDGFR-alpha was not affected by gonadotropin (eCG) stimulation but PDGF-C and PDGFR-beta decreased. Administration of estradiol decreased PDGF and their receptors. To further probe the differential regulation of PDGF family members by eCG and estradiol, we co-administered eCG with estrogen antagonist, ICI 182780. Increase in PDGFR-alpha in the absence of estradiol suggests direct effects of FSH signaling. During the estrous cycle in mice PDGF-C, PDGF-D and PDGFR-alpha mRNA levels were higher at the proestrous. By IHC, we report for the first time the localization of PDGF-C, PDGFR-alpha and PDGFR-beta protein in mouse ovarian compartments including the surface epithelium that is also altered in mutants. Immunostaining of PDGFRs increased as the follicle developed to preantral stage and declined thereafter. Thus, FSH modulates PDGF family members, partly via E2, suggesting that loss of FSH-R signaling causes an imbalance of PDGF family members predisposing the abnormal ovarian follicular environment for inducing tumorigenesis in aging FORKO mice.
Error studies for SNS Linac. Part 1: Transverse errors
Crandall, K.R.
The SNS linac consist of a radio-frequency quadrupole (RFQ), a drift-tube linac (DTL), a coupled-cavity drift-tube linac (CCDTL) and a coupled-cavity linac (CCL). The RFQ and DTL are operated at 402.5 MHz; the CCDTL and CCL are operated at 805 MHz. Between the RFQ and DTL is a medium-energy beam-transport system (MEBT). This error study is concerned with the DTL, CCDTL and CCL, and each will be analyzed separately. In fact, the CCL is divided into two sections, and each of these will be analyzed separately. The types of errors considered here are those that affect the transverse characteristics of the beam. The errors that cause the beam center to be displaced from the linac axis are quad displacements and quad tilts. The errors that cause mismatches are quad gradient errors and quad rotations (roll).
Error begat error: design error analysis and prevention in social infrastructure projects.
Love, Peter E D; Lopez, Robert; Edwards, David J; Goh, Yang M
Design errors contribute significantly to cost and schedule growth in social infrastructure projects and to engineering failures, which can result in accidents and loss of life. Despite considerable research that has addressed their error causation in construction projects they still remain prevalent. This paper identifies the underlying conditions that contribute to design errors in social infrastructure projects (e.g. hospitals, education, law and order type buildings). A systemic model of error causation is propagated and subsequently used to develop a learning framework for design error prevention. The research suggests that a multitude of strategies should be adopted in congruence to prevent design errors from occurring and so ensure that safety and project performance are ameliorated.
LANDSAT imagery analysis: An aid for predicting landslide prone areas for highway construction. [in Arkansas
NASA Technical Reports Server (NTRS)
Macdonald, H. C.; Grubbs, R. S.
The most obvious landform features of geologic significance revealed on LANDSAT imagery are linear trends or lineaments. These trends were found to correspond, at least to a large degree, with unmapped faults or complex fracture zones. LANDSAT imagery analysis in northern Arkansas revealed a lineament complex which provides a remarkable correlation with landslide-prone areas along major highway routes. The weathering properties of various rock types, which are considered in designing stable cut slopes and drainage structures, appear to be adversely influenced by the location and trends of LANDSAT defined lineaments. Geologic interpretation of LANDSAT imagery, where applicable and utilized effectively, provides the highway engineer with a tool for predicting and evaluating landslide-prone areas.
Why dissociation and schizotypy overlap: the joint influence of fantasy proneness, cognitive failures, and childhood trauma.
Giesbrecht, Timo; Merckelbach, Harald; Kater, Maartje; Sluis, Anne Fetsje
A number of studies have noted that dissociative symptoms (e.g., feelings of derealization, depersonalization, memory complaints, absorption) overlap with the tendency to report psychotic-like experiences (i.e., schizotypy). The question arises as to what may account for the shared variance between dissociation and schizotypy. The present study investigated whether fantasy proneness, cognitive failures, and childhood trauma may jointly explain the dissociation-schizotypy link. To this end, we administered the Dissociative Experiences Scale, the Schizotypal Personality Scale, the Creative Experiences Questionnaire, the Cognitive Failures Questionnaire, and the Childhood Trauma Questionnaire to a sample of undergraduates (N = 185). Fantasy proneness, cognitive failures, and childhood trauma together explained substantial part (58%) of the dissociation-schizotypy link. The present study succeeded in explaining a considerate part of the shared variance between dissociation and schizotypy.
Simple shielding reduces dose to the contralateral breast during prone breast cancer radiotherapy
Goyal, Uma Locke, Angela; Smith-Raymond, Lexie; Georgiev, Georgi N.
Our goal was to design a prone breast shield for the contralateral breast and study its efficacy in decreasing scatter radiation to the contralateral breast in a prone breast phantom setup receiving radiation therapy designed for breast cancer. We constructed a prone breast phantom setup consisting of (1) A thermoplastic mask with a left-sided depression created by a water balloon for a breast shape; (2) 2 plastic bags to hold water in the thermoplastic mask depression; (3) 2000 mL of water to fill the thermoplastic mask depression to create a water-based false breast; (4) 1-cm thick bolus placed in the contralateral breast holder; (5) 2 lead (Pb) sheets, each 0.1-cm thick for blocking scatter radiation in the contralateral bolus-based false breast; (6) a prone breast board to hold the thermoplastic mask, water, bolus, and lead; (7) 9 cm solid water on top of the breast board to simulate body; (8) a diode was used to verify dose for each treatment field of the treated water-based breast; (9) metal–oxide–semiconductor-field effect transistor (MOSFET) dosimeters to measure dose to the contralateral bolus-based breast. The phantom prone breast setup was CT simulated and treatment was designed with 95% isodose line covering the treated breast. The maximum dose was 107.1%. Megavoltage (MV) port images ensured accurate setup. Measurements were done using diodes on the treated water-based breast and MOSFET dosimeters at the medial and lateral sides of the contralateral bolus-based breast without and with the Pb shield. Five treatments were done for each of the 3 data sets and recorded individually for statistical purposes. All treatments were completed with 6 MV photons at 200 cGy per treatment. The dose contributions from each of the 3 data sets including 15 treatments total without and with the prone lead shield to the medial and lateral portions of contralateral bolus-based breast were averaged individually. Unshielded dose means were 37.11 and 2.94 cGy, and
Probability mapping of indoor radon-prone areas using disjunctive kriging.
Raspa, G; Salvi, F; Torri, G
After a reference to the use of maps of radon-prone areas for indoor radon risk management, and to the methods used to produce them, there is a brief illustration of the geostatistical method of disjunctive kriging (DK) introduced by G. Matheron as a substitute for conditional expectation. There are some good reasons of using this method for the mapping of radon-prone areas as follows: (1) spatial correlation is exploited; (2) unbiasedness is conserved even in the conditions of quasi-stationarity; (3) lognormality of the data is not required; (4) choosing the point estimation allows drawing up smooth probability maps. An application of DK is also presented for the production of probability maps in a campaign of indoor radon measurements conducted by Institute for Environmental Protection and Research, in the provinces of Rome and Viterbo (Central Italy). In the application, it is assessed in particular how much the spatial correlation, even though low, influences the results.
Meralgia Paresthetica after Prone Positioning Ventilation in the Intensive Care Unit
Ballegaard, Martin; Bestle, Morten H.; Tfelt-Hansen, Peer
Meralgia paresthetica (MP) is a mononeuropathy of the lateral femoral cutaneous nerve (LFCN) caused by external compression of the nerve during its course close to the anterior superior iliac spine. We present a case of a patient with acute respiratory distress induced by Legionella pneumonia who was admitted to the intensive care unit (ICU) for mechanical ventilation. In the ICU, the patient received one session of prone position ventilation for 8.5 consecutive hours. At evaluation six months later, the patient reported persistent bilateral numbness of the anterolateral thigh, which he complained had begun right after he woke up at the ICU. He was referred for further neurological and neurophysiological examination and was diagnosed with bilateral MP, a condition never previously described as a complication to mechanical ventilation in prone position in the ICU. PMID:27752369
The Prone Position During Surgery and its Complications: A Systematic Review and Evidence-Based Guidelines
Kwee, Melissa M.; Ho, Yik-Hong; Rozen, Warren M.
Surgery in the prone position is often a necessity when access to posterior anatomic structures is required. However, many complications are known to be associated with this type of surgery, as physiologic changes occur with increased pressure to anterior structures. While several studies have discussed postoperative vision loss, much fewer studies with lower levels of evidence have addressed other complications. A systematic literature review was conducted using 2 different databases, and 53 papers were regarded as appropriate for inclusion. Qualitative and quantitative analysis was performed. Thirteen complications were identified. Postoperative vision loss and cardiovascular complications, including hypovolemia and cardiac arrest, had the most number of studies and highest level of evidence. Careful planning for optimal positioning, padding, timing, as well as increased vigilance are evidence-based recommendations where operative prone positioning is required. PMID:25692433
Simple shielding reduces dose to the contralateral breast during prone breast cancer radiotherapy.
Goyal, Uma; Locke, Angela; Smith-Raymond, Lexie; Georgiev, Georgi N
Our goal was to design a prone breast shield for the contralateral breast and study its efficacy in decreasing scatter radiation to the contralateral breast in a prone breast phantom setup receiving radiation therapy designed for breast cancer. We constructed a prone breast phantom setup consisting of (1) A thermoplastic mask with a left-sided depression created by a water balloon for a breast shape; (2) 2 plastic bags to hold water in the thermoplastic mask depression; (3) 2000mL of water to fill the thermoplastic mask depression to create a water-based false breast; (4) 1-cm thick bolus placed in the contralateral breast holder; (5) 2 lead (Pb) sheets, each 0.1-cm thick for blocking scatter radiation in the contralateral bolus-based false breast; (6) a prone breast board to hold the thermoplastic mask, water, bolus, and lead; (7) 9cm solid water on top of the breast board to simulate body; (8) a diode was used to verify dose for each treatment field of the treated water-based breast; (9) metal-oxide-semiconductor-field effect transistor (MOSFET) dosimeters to measure dose to the contralateral bolus-based breast. The phantom prone breast setup was CT simulated and treatment was designed with 95% isodose line covering the treated breast. The maximum dose was 107.1%. Megavoltage (MV) port images ensured accurate setup. Measurements were done using diodes on the treated water-based breast and MOSFET dosimeters at the medial and lateral sides of the contralateral bolus-based breast without and with the Pb shield. Five treatments were done for each of the 3 data sets and recorded individually for statistical purposes. All treatments were completed with 6MV photons at 200cGy per treatment. The dose contributions from each of the 3 data sets including 15 treatments total without and with the prone lead shield to the medial and lateral portions of contralateral bolus-based breast were averaged individually. Unshielded dose means were 37.11 and 2.94cGy, and shielded dose
Thoracic disc herniation: An unusual complication after prone positioning in spinal surgery
Ebrahim, Mohammed Zahier; Vlok, Adriaan J.
Neurological complications of the prone position have been well documented. Post-operative paraplegia and neurological deterioration unrelated to the site of surgery after proning in spinal surgery is a rare but potentially devastating complication. We describe the case of a 47 year old female who underwent an L4/5 discectomy and posterior instrumented fusion. A few hours after surgery she developed bilateral lower limb weakness with a T11 sensory level. Post-operative MRI revealed an acute disc herniation at the T11/12 level with associated spinal cord compression. This was not present on the pre-operative imaging. A subsequent T11/12 discectomy and instrumented fusion was performed and the patient's motor and sensory function returned to normal.
Left-sided thoracoscopy in the prone position for surgery of distal esophageal benign pathologies
Issaka, Adamu; Kara, Hasan Volkan; Eldem, Barkin
Exposure of the distal esophagus can be achieved by a wide variety of surgical approaches. The standard procedure is mostly by laparoscopy. In cases where laparoscopy is relatively contraindicated, thoracoscopy is preferred. In this case, exposure of the distal esophagus from the aorta, heart and lung is technically challenging using thoracoscopy in the right lateral decubitus position. Surgery in the prone position for esophageal cancer has been successfully described in previous literature. We present our experience with left-sided thoracoscopy in the prone position in three patients with benign distal esophageal pathologies. This approach provided a much better exposure of the distal esophagus and enabled a successful surgery to be done in all patients with less manipulation of the lung. PMID:27489640
The effect of auditory verbal imagery on signal detection in hallucination-prone individuals
Moseley, Peter; Smailes, David; Ellison, Amanda; Fernyhough, Charles
Cognitive models have suggested that auditory hallucinations occur when internal mental events, such as inner speech or auditory verbal imagery (AVI), are misattributed to an external source. This has been supported by numerous studies indicating that individuals who experience hallucinations tend to perform in a biased manner on tasks that require them to distinguish self-generated from non-self-generated perceptions. However, these tasks have typically been of limited relevance to inner speech models of hallucinations, because they have not manipulated the AVI that participants used during the task. Here, a new paradigm was employed to investigate the interaction between imagery and perception, in which a healthy, non-clinical sample of participants were instructed to use AVI whilst completing an auditory signal detection task. It was hypothesized that AVI-usage would cause participants to perform in a biased manner, therefore falsely detecting more voices in bursts of noise. In Experiment 1, when cued to generate AVI, highly hallucination-prone participants showed a lower response bias than when performing a standard signal detection task, being more willing to report the presence of a voice in the noise. Participants not prone to hallucinations performed no differently between the two conditions. In Experiment 2, participants were not specifically instructed to use AVI, but retrospectively reported how often they engaged in AVI during the task. Highly hallucination-prone participants who retrospectively reported using imagery showed a lower response bias than did participants with lower proneness who also reported using AVI. Results are discussed in relation to prominent inner speech models of hallucinations. PMID:26435050
Long-term Clinical Outcomes of Whole-Breast Irradiation Delivered in the Prone Position
Stegman, Lauren D.; Beal, Katherine P.; Hunt, Margie A.; Fornier, Monica N.; McCormick, Beryl . E-mail: email@example.com
Purpose: The aim of this study was to evaluate retrospectively the effectiveness and toxicity of post-lumpectomy whole-breast radiation therapy delivered with prone positioning. Methods and Materials: Between September 1992 and August 2004, 245 women with 248 early-stage invasive or in situ breast cancers were treated using a prone breast board. Photon fields treated the whole breast to 46 to 50.4 Gy with standard fractionation. The target volume was clinically palpable breast tissue; no attempt was made to irradiate chest wall lymphatics. Tumor bed boosts were delivered in 85% of cases. Adjuvant chemotherapy and hormonal therapy were administered to 42% and 62% of patients, respectively. Results: After a median follow-up of 4.9 years, the 5 year actuarial true local and elsewhere ipsilateral breast tumor recurrence rates were 4.8% and 1.3%, respectively. The 5-year actuarial rates of regional nodal recurrence and distant metastases were 1.6% and 7.4%. Actuarial disease-free, disease-specific, and overall survival rates at 5 years were 89.4%, 97.3%, and 93%, respectively. Treatment breaks were required by 2.4% of patients. Grade 3 acute dermatitis and edema were each limited to 2% of patients. Only 4.9% of patients complained of acute chest wall discomfort. Chronic Grade 2 to 3 skin and subcutaneous tissue toxicities were reported in 4.4% and 13.7% of patients, respectively. Conclusions: Prone position breast radiation results in similar long-term disease control with a favorable toxicity profile compared with standard supine tangents. The anatomic advantages of prone positioning may contribute to improving the therapeutic ratio of post-lumpectomy radiation by improving dose homogeneity and minimizing incidental cardiac and lung dose.
Electromagnetic Tracking of Intrafraction Prostate Displacement in Patients Externally Immobilized in the Prone Position
Bittner, Nathan; Wallner, Kent E.; Merrick, Gregory S.
Purpose: To evaluate intrafraction prostate displacement among patients immobilized in the prone position using real-time monitoring of implanted radiofrequency transponders. Methods and Materials: The Calypso localization system was used to track prostate motion in patients receiving external beam radiation therapy (XRT) for prostate cancer. All patients were treated in the prone position and immobilized with a thermoplastic immobilization device. Real-time measurement of prostate displacement was recorded for each treatment fraction. These measurements were used to determine the duration and magnitude of displacement along the three directional axes. Results: The calculated centroid of the implanted transponders was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 38.0%, 13.9%, and 4.5% of the time. In the lateral dimension, the centroid was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 2.7%, 0.4%, and 0.06% of the time. In the superior-inferior dimension, the centroid was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 16.1%, 4.7%, and 1.5% of the time, respectively. In the anterior-posterior dimension, the centroid was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 13.4%, 3.0%, and 0.5% of the time. Conclusions: Intrafraction prostate displacement in the prone position is comparable to that in the supine position. For patients with large girth, in whom the supine position may preclude accurate detection of implanted radiofrequency transponders, treatment in the prone position is a suitable alternative.
Anesthetic Management of the Parturient for Lumbar Disc Surgery in the Prone Position
Martel, Colleen G.; Volpi-Abadie, Jacqueline; Ural, Kelly
Background While back pain is common in pregnancy, urgent surgical intervention is rarely required. Case Report A parturient in the third trimester presented with foot drop and sensory deficits. Surgical intervention was deemed necessary and was performed in the prone position to facilitate exposure. A multidisciplinary approach was vital to the management plan. Conclusion For any pregnant patient undergoing nonobstetric surgery, the care provided should be individualized and thoughtful, keeping in mind both the mother and fetus. PMID:26412999
Clinical review: Intra-abdominal hypertension: does it influence the physiology of prone ventilation?
Kirkpatrick, Andrew W; Pelosi, Paolo; De Waele, Jan J; Malbrain, Manu Lng; Ball, Chad G; Meade, Maureen O; Stelfox, Henry T; Laupland, Kevin B
Prone ventilation (PV) is a ventilatory strategy that frequently improves oxygenation and lung mechanics in critical illness, yet does not consistently improve survival. While the exact physiologic mechanisms related to these benefits remain unproven, one major theoretical mechanism relates to reducing the abdominal encroachment upon the lungs. Concurrent to this experience is increasing recognition of the ubiquitous role of intra-abdominal hypertension (IAH) in critical illness, of the relationship between IAH and intra-abdominal volume or thus the compliance of the abdominal wall, and of the potential difference in the abdominal influences between the extrapulmonary and pulmonary forms of acute respiratory distress syndrome. The present paper reviews reported data concerning intra-abdominal pressure (IAP) in association with the use of PV to explore the potential influence of IAH. While early authors stressed the importance of gravitationally unloading the abdominal cavity to unencumber the lung bases, this admonition has not been consistently acknowledged when PV has been utilized. Basic data required to understand the role of IAP/IAH in the physiology of PV have generally not been collected and/or reported. No randomized controlled trials or meta-analyses considered IAH in design or outcome. While the act of proning itself has a variable reported effect on IAP, abundant clinical and laboratory data confirm that the thoracoabdominal cavities are intimately linked and that IAH is consistently transmitted across the diaphragm--although the transmission ratio is variable and is possibly related to the compliance of the abdominal wall. Any proning-related intervention that secondarily influences IAP/IAH is likely to greatly influence respiratory mechanics and outcomes. Further study of the role of IAP/IAH in the physiology and outcomes of PV in hypoxemic respiratory failure is thus required. Theories relating inter-relations between prone positioning and the
Severe acute respiratory distress syndrome in a child with malaria: favorable response to prone positioning.
Flores, Jose C; Imaz, Ana; López-Herce, Jesús; Seriñá, Carlota
We present the case of a 4-year-old boy with malaria who developed acute respiratory distress syndrome with severe hypoxemia refractory to mechanical ventilation and inhaled nitric oxide. Placing the patient in prone position immediately and persistently improved oxygenation: the ratio of P(aO(2)) to fraction of inspired oxygen rose from 47 to 180 mm Hg and the oxygenation index decreased from 40 to 11. The patient survived, with no respiratory sequelae.
Applications of Digital PCR for Clinical Microbiology.
Kuypers, Jane; Jerome, Keith R
Digital PCR (dPCR) is an important new tool for use in the clinical microbiology laboratory. Its advantages over quantitative PCR (qPCR), including absolute quantification without a standard curve, improved precision, improved accuracy in the presence of inhibitors, and more accurate quantitation when amplification efficiency is low, make dPCR the assay of choice for several specimen testing applications. This mini-review will discuss the advantages and disadvantages of dPCR compared to qPCR, its applications in clinical microbiology and the considerations for implementation of the method in a clinical laboratory.
Rosuvastatin Treatment Prevents Progressive Kidney Inflammation and Fibrosis in Stroke-Prone Rats
Gianella, Anita; Nobili, Elena; Abbate, Mauro; Zoja, Carla; Gelosa, Paolo; Mussoni, Luciana; Bellosta, Stefano; Canavesi, Monica; Rottoli, Daniela; Guerrini, Uliano; Brioschi, Maura; Banfi, Cristina; Tremoli, Elena; Remuzzi, Giuseppe; Sironi, Luigi
Salt-loaded, spontaneously hypertensive stroke-prone rats show progressive increases in blood pressure and proteinuria and accumulate acute-phase proteins in body fluids, modeling events during renal damage. The aim of this study was to assess the pathological events occurring in the kidney of spontaneously hypertensive stroke-prone rats over time and evaluate the effects of statin treatment, which is known to improve renal and cardiovascular outcomes. Kidneys of male spontaneously hypertensive stroke-prone rats euthanized at different stages of proteinuria showed progressive inflammatory cell infiltration, the accumulation of α-smooth muscle actin-positive cells, degenerative changes in podocytes, and severe fibrosis. These were accompanied by an imbalance in the plasminogen/plasmin and metalloprotease systems characterized by the increased renal expression of plasminogen activator inhibitor-1, tissue plasminogen activator, and urokinase plasminogen activator; the net result was an increase in plasmin and matrix metalloproteinase (MMP)-2 and a reduction in MMP-9 activity. Chronic treatment with the hydrophilic rosuvastatin had renoprotective effects in terms of morphology and inflammation and prevented the changes in plasmin, MMP-2, and MMP-9 activity. These effects were independent of the changes in blood pressure and plasma lipid levels. Treatment with the lipophilic simvastatin was not renoprotective. These data suggest that rosuvastatin may have potential utility as a therapeutic option in renal diseases that are characterized by inflammation and fibrosis. PMID:17392157
Factors associated with larval control practices in a dengue outbreak prone area.
Mohamad, Mariam; Selamat, Mohamad Ikhsan; Ismail, Zaliha
In order to reduce the risk of dengue outbreak recurrence in a dengue outbreak prone area, the members of the community need to sustain certain behavior to prevent mosquito from breeding. Our study aims to identify the factors associated with larval control practices in this particular community. A cross-sectional study involves 322 respondents living in a dengue outbreak prone area who were interviewed using a pretested questionnaire. The level of knowledge about Aedes mosquitoes, dengue transmission, its symptoms, and personal preventive measures ranges from fair to good. The level of attitude towards preventive measures was high. However, reported level of personal larval control practices was low (33.2%). Our multiple logistic regression analysis showed that only those with a good level of attitude towards personal preventive measure and frequent attendance to health campaigns were significantly associated with the good larval control practices. We conclude that, in a dengue outbreak prone area, having a good attitude towards preventive measures and frequent participation in health campaigns are important factors to sustain practices on larval control.
Non-invasive ventilation in prone position for refractory hypoxemia after bilateral lung transplantation.
Feltracco, Paolo; Serra, Eugenio; Barbieri, Stefania; Persona, Paolo; Rea, Federico; Loy, Monica; Ori, Carlo
Temporary graft dysfunction with gas exchange abnormalities is a common finding during the postoperative course of a lung transplant and is often determined by the post-reimplantation syndrome. Supportive measures including oxygen by mask, inotropes, diuretics, and pulmonary vasodilators are usually effective in non-severe post-reimplantation syndromes. However, in less-responsive clinical pictures, tracheal intubation with positive pressure ventilation, or non-invasive positive pressure ventilation (NIV), is necessary. We report on the clinical course of two patients suffering from refractory hypoxemia due to post-reimplantation syndrome treated with NIV in the prone and Trendelenburg positions. NIV was well tolerated and led to resolution of atelectactic areas and dishomogeneous lung infiltrates. Repeated turning from supine to prone under non invasive ventilation determined a stable improvement of gas exchange and prevented a more invasive approach. Even though NIV in the prone position has not yet entered into clinical practice, it could be an interesting option to achieve a better match between ventilation and perfusion. This technique, which we successfully applied in lung transplantation, can be easily extended to other lung diseases with non-recruitable dorso-basal areas.
The Chapman psychosis-proneness scales: Consistency across culture and time.
Chan, Raymond C K; Shi, Hai-song; Geng, Fu-lei; Liu, Wen-hua; Yan, Chao; Wang, Yi; Gooding, Diane C
The purpose of the present study was to examine the factor structure and the temporal stability of the Chapman psychosis-proneness scales in a representative sample of nonclinical Chinese young adults. The four psychosis-proneness scales evaluated were the Perceptual Aberration (PAS), Magical Ideation (MIS), revised Social Anhedonia (RSAS), and revised Physical Anhedonia (RPAS) scales. The sample consisted of 1724 young adults with a mean age of 18.8 years (S.D. = 0.84). The results of the confirmatory factor analyses indicated that the best fitting model was a two-factor model with positive schizotypy (PER and MIS) scales and negative schizotypy (RSAS and RPAS) scales. The data add to the growing literature indicating that the measurement of schizotypal traits is consistent across cultures. In addition, the results support the measurement invariance of the Chapman psychosis-proneness scales across time, i.e., there was ample evidence of test-retest reliability over a test interval of 6 months.
Children's Scale Errors with Tools
ERIC Educational Resources Information Center
Casler, Krista; Eshleman, Angelica; Greene, Kimberly; Terziyan, Treysi
Children sometimes make "scale errors," attempting to interact with tiny object replicas as though they were full size. Here, we demonstrate that instrumental tools provide special insight into the origins of scale errors and, moreover, into the broader nature of children's purpose-guided reasoning and behavior with objects. In Study 1, 1.5- to…
Dual Processing and Diagnostic Errors
ERIC Educational Resources Information Center
Norman, Geoff
In this paper, I review evidence from two theories in psychology relevant to diagnosis and diagnostic errors. "Dual Process" theories of thinking, frequently mentioned with respect to diagnostic error, propose that categorization decisions can be made with either a fast, unconscious, contextual process called System 1 or a slow, analytical,…
Explaining Errors in Children's Questions
ERIC Educational Resources Information Center
Rowland, Caroline F.
The ability to explain the occurrence of errors in children's speech is an essential component of successful theories of language acquisition. The present study tested some generativist and constructivist predictions about error on the questions produced by ten English-learning children between 2 and 5 years of age. The analyses demonstrated that,…
Error Estimates for Mixed Methods.
This paper presents abstract error estimates for mixed methods for the approximate solution of elliptic boundary value problems. These estimates are...then applied to obtain quasi-optimal error estimates in the usual Sobolev norms for four examples: three mixed methods for the biharmonic problem and a mixed method for 2nd order elliptic problems. (Author)
Operational Interventions to Maintenance Error
NASA Technical Reports Server (NTRS)
Kanki, Barbara G.; Walter, Diane; Dulchinos, VIcki
A significant proportion of aviation accidents and incidents are known to be tied to human error. However, research of flight operational errors has shown that so-called pilot error often involves a variety of human factors issues and not a simple lack of individual technical skills. In aircraft maintenance operations, there is similar concern that maintenance errors which may lead to incidents and accidents are related to a large variety of human factors issues. Although maintenance error data and research are limited, industry initiatives involving human factors training in maintenance have become increasingly accepted as one type of maintenance error intervention. Conscientious efforts have been made in re-inventing the team7 concept for maintenance operations and in tailoring programs to fit the needs of technical opeRAtions. Nevertheless, there remains a dual challenge: 1) to develop human factors interventions which are directly supported by reliable human error data, and 2) to integrate human factors concepts into the procedures and practices of everyday technical tasks. In this paper, we describe several varieties of human factors interventions and focus on two specific alternatives which target problems related to procedures and practices; namely, 1) structured on-the-job training and 2) procedure re-design. We hope to demonstrate that the key to leveraging the impact of these solutions comes from focused interventions; that is, interventions which are derived from a clear understanding of specific maintenance errors, their operational context and human factors components.
Error Correction, Revision, and Learning
ERIC Educational Resources Information Center
Truscott, John; Hsu, Angela Yi-ping
Previous research has shown that corrective feedback on an assignment helps learners reduce their errors on that assignment during the revision process. Does this finding constitute evidence that learning resulted from the feedback? Differing answers play an important role in the ongoing debate over the effectiveness of error correction,…
Human Error: A Concept Analysis
NASA Technical Reports Server (NTRS)
Hansen, Frederick D.
Human error is the subject of research in almost every industry and profession of our times. This term is part of our daily language and intuitively understood by most people however, it would be premature to assume that everyone's understanding of human error s the same. For example, human error is used to describe the outcome or consequence of human action, the causal factor of an accident, deliberate violations,a nd the actual action taken by a human being. As a result, researchers rarely agree on the either a specific definition or how to prevent human error. The purpose of this article is to explore the specific concept of human error using Concept Analysis as described by Walker and Avant (1995). The concept of human error is examined as currently used in the literature of a variety of industries and professions. Defining attributes and examples of model, borderline, and contrary cases are described. The antecedents and consequences of human error are also discussed and a definition of human error is offered.
Twenty questions about student errors
NASA Astrophysics Data System (ADS)
Fisher, Kathleen M.; Lipson, Joseph Isaac
Errors in science learning (errors in expression of organized, purposeful thought within the domain of science) provide a window through which glimpses of mental functioning can be obtained. Errors are valuable and normal occurrences in the process of learning science. A student can use his/her errors to develop a deeper understanding of a concept as long as the error can be recognized and appropriate, informative feedback can be obtained. A safe, non-threatening, and nonpunitive environment which encourages dialogue helps students to express their conceptions and to risk making errors. Pedagogical methods that systematically address common student errors produce significant gains in student learning. Just as the nature-nurture interaction is integral to the development of living things, so the individual-environment interaction is basic to thought processes. At a minimum, four systems interact: (1) the individual problem solver (who has a worldview, relatively stable cognitive characteristics, relatively malleable mental states and conditions, and aims or intentions), (2) task to be performed (including relative importance and nature of the task), (3) knowledge domain in which task is contained, and (4) the environment (including orienting conditions and the social and physical context).Several basic assumptions underlie research on errors and alternative conceptions. Among these are: Knowledge and thought involve active, constructive processes; there are many ways to acquire, organize, store, retrieve, and think about a given concept or event; and understanding is achieved by successive approximations. Application of these ideas will require a fundamental change in how science is taught.
Onorbit IMU alignment error budget
NASA Technical Reports Server (NTRS)
Corson, R. W.
The Star Tracker, Crew Optical Alignment Sight (COAS), and Inertial Measurement Unit (IMU) from a complex navigation system with a multitude of error sources were combined. A complete list of the system errors is presented. The errors were combined in a rational way to yield an estimate of the IMU alignment accuracy for STS-1. The expected standard deviation in the IMU alignment error for STS-1 type alignments was determined to be 72 arc seconds per axis for star tracker alignments and 188 arc seconds per axis for COAS alignments. These estimates are based on current knowledge of the star tracker, COAS, IMU, and navigation base error specifications, and were partially verified by preliminary Monte Carlo analysis.
Angle interferometer cross axis errors
Bryan, J.B.; Carter, D.L.; Thompson, S.L.
Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them by remachining the reference surfaces.
Angle interferometer cross axis errors
NASA Astrophysics Data System (ADS)
Bryan, J. B.; Carter, D. L.; Thompson, S. L.
Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them.
NASA Technical Reports Server (NTRS)
Mcruer, D. T.; Clement, W. F.; Allen, R. W.
Human errors tend to be treated in terms of clinical and anecdotal descriptions, from which remedial measures are difficult to derive. Correction of the sources of human error requires an attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A comprehensive analytical theory of the cause-effect relationships governing propagation of human error is indispensable to a reconstruction of the underlying and contributing causes. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation, maritime, automotive, and process control operations is highlighted. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.
Discretization errors in particle tracking
NASA Astrophysics Data System (ADS)
Carmon, G.; Mamman, N.; Feingold, M.
High precision video tracking of microscopic particles is limited by systematic and random errors. Systematic errors are partly due to the discretization process both in position and in intensity. We study the behavior of such errors in a simple tracking algorithm designed for the case of symmetric particles. This symmetry algorithm uses interpolation to estimate the value of the intensity at arbitrary points in the image plane. We show that the discretization error is composed of two parts: (1) the error due to the discretization of the intensity, bD and (2) that due to interpolation, bI. While bD behaves asymptotically like N-1 where N is the number of intensity gray levels, bI is small when using cubic spline interpolation.
The Benefits of Prone SPECT Myocardial Perfusion Imaging in Reducing Both Artifact Defects and Patient Radiation Exposure
Stathaki, Maria; Koukouraki, Sophia; Papadaki, Emmanouela; Tsaroucha, Angeliki; Karkavitsas, Nikolaos
Background Prone imaging has been demonstrated to minimize diaphragmatic and breast tissue attenuation. Objectives To determine the role of prone imaging on the reduction of unnecessary rest perfusion studies and coronary angiographies performed, thus decreasing investigation time and radiation exposure. Methods We examined 139 patients, 120 with an inferior wall and 19 with an anterior wall perfusion defect that might represented attenuation artifact. Post-stress images were acquired in both the supine and prone position. Coronary angiography was used as the "gold standard" for evaluating coronary artery patency. The study was terminated and rest imaging was obviated in the presence of complete improvement of the defect in the prone position. Quantitative interpretation was performed. Results were compared with clinical data and coronary angiographic findings. Results Prone acquisition correctly revealed defect improvement in 89 patients (89/120) with inferior wall and 12 patients (12/19) with anterior wall attenuation artifact. Quantitative analysis demonstrated statistically significant difference in the mean summed stress scores (SSS) of supine and mean SSS of prone studies in patients with disappearing inferior wall defect in the prone position and patent right coronary artery (true negative results). The mean difference between SSS in supine and in prone position was higher with disappearing than with remaining defects. Conclusion Technetium-99m (Tc-99m) tetrofosmin myocardial perfusion imaging with the patient in the prone position overcomes soft tissue attenuation; moreover it provides an inexpensive, accurate approach to limit the number of unnecessary rest perfusion studies and coronary angiographies performed. PMID:26559981
Calibration-free assays on standard real-time PCR devices
Debski, Pawel R.; Gewartowski, Kamil; Bajer, Seweryn; Garstecki, Piotr
Quantitative Polymerase Chain Reaction (qPCR) is one of central techniques in molecular biology and important tool in medical diagnostics. While being a golden standard qPCR techniques depend on reference measurements and are susceptible to large errors caused by even small changes of reaction efficiency or conditions that are typically not marked by decreased precision. Digital PCR (dPCR) technologies should alleviate the need for calibration by providing absolute quantitation using binary (yes/no) signals from partitions provided that the basic assumption of amplification a single target molecule into a positive signal is met. Still, the access to digital techniques is limited because they require new instruments. We show an analog-digital method that can be executed on standard (real-time) qPCR devices. It benefits from real-time readout, providing calibration-free assessment. The method combines advantages of qPCR and dPCR and bypasses their drawbacks. The protocols provide for small simplified partitioning that can be fitted within standard well plate format. We demonstrate that with the use of synergistic assay design standard qPCR devices are capable of absolute quantitation when normal qPCR protocols fail to provide accurate estimates. We list practical recipes how to design assays for required parameters, and how to analyze signals to estimate concentration. PMID:28327545
Calibration-free assays on standard real-time PCR devices
NASA Astrophysics Data System (ADS)
Debski, Pawel R.; Gewartowski, Kamil; Bajer, Seweryn; Garstecki, Piotr
Quantitative Polymerase Chain Reaction (qPCR) is one of central techniques in molecular biology and important tool in medical diagnostics. While being a golden standard qPCR techniques depend on reference measurements and are susceptible to large errors caused by even small changes of reaction efficiency or conditions that are typically not marked by decreased precision. Digital PCR (dPCR) technologies should alleviate the need for calibration by providing absolute quantitation using binary (yes/no) signals from partitions provided that the basic assumption of amplification a single target molecule into a positive signal is met. Still, the access to digital techniques is limited because they require new instruments. We show an analog-digital method that can be executed on standard (real-time) qPCR devices. It benefits from real-time readout, providing calibration-free assessment. The method combines advantages of qPCR and dPCR and bypasses their drawbacks. The protocols provide for small simplified partitioning that can be fitted within standard well plate format. We demonstrate that with the use of synergistic assay design standard qPCR devices are capable of absolute quantitation when normal qPCR protocols fail to provide accurate estimates. We list practical recipes how to design assays for required parameters, and how to analyze signals to estimate concentration.
Quantification Bias Caused by Plasmid DNA Conformation in Quantitative Real-Time PCR Assay
Lin, Chih-Hui; Chen, Yu-Chieh; Pan, Tzu-Ming
Quantitative real-time PCR (qPCR) is the gold standard for the quantification of specific nucleic acid sequences. However, a serious concern has been revealed in a recent report: supercoiled plasmid standards cause significant over-estimation in qPCR quantification. In this study, we investigated the effect of plasmid DNA conformation on the quantification of DNA and the efficiency of qPCR. Our results suggest that plasmid DNA conformation has significant impact on the accuracy of absolute quantification by qPCR. DNA standard curves shifted significantly among plasmid standards with different DNA conformations. Moreover, the choice of DNA measurement method and plasmid DNA conformation may also contribute to the measurement error of DNA standard curves. Due to the multiple effects of plasmid DNA conformation on the accuracy of qPCR, efforts should be made to assure the highest consistency of plasmid standards for qPCR. Thus, we suggest that the conformation, preparation, quantification, purification, handling, and storage of standard plasmid DNA should be described and defined in the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) to assure the reproducibility and accuracy of qPCR absolute quantification. PMID:22194997
Gut microbiome in sudden infant death syndrome (SIDS) differs from that in healthy comparison babies and offers an explanation for the risk factor of prone position.
Highet, Amanda R; Berry, Anne M; Bettelheim, Karl A; Goldwater, Paul N
The role of bacteria in the causation of sudden infant death syndrome (SIDS) is gaining acceptance. Mainstream research favouring respiratory compromise has failed to provide a plausible pathogenetic mechanism despite many years of investigation and thousands of research papers. Bacterial colonisation of the colon of the human infant is influenced by many factors including age, mode of delivery, diet, environment, and antibiotic exposure. The gut microbiome influences development of the immune system. The gut microflora could be important in protection against the bacteria and/or their toxins purportedly involved in SIDS pathogenesis. The aim was to perform a preliminary investigation of the gut microflora in sudden infant death syndrome (SIDS) compared with live comparison babies. The intestinal contents from 52 SIDS, and 102 faecal samples from age-matched live comparison infants were screened by PCR to target 16s RNA genes of Clostridium innocuum, Cl. Perfringens, Cl. difficile, Bacteroides thetaiotaomicron and Staphylococcus aureus. Gut colonisation of the babies with these bacteria was analysed in relation to age, gender and type of feeding; and for SIDS babies sleeping position. Cl. difficile, Cl. innocuum and B. thetaiotaomicron were significantly associated with SIDS with 25%, 46% and 30% of cases PCR positive for these respective bacteria compared with only 6%, 23% and 8.8% respectively in the comparison group. SIDS babies had dual colonisation by both Cl. perfringens and Cl. difficile significantly more often than comparison babies and also with triple colonisation by Cl. perfringens, Cl. difficile and Cl. innocuum. SIDS babies were more often colonised by S. aureus than comparison babies. In addition, SIDS babies found prone were significantly more likely to be colonised by S. aureus than for other positions recorded (OR = ∞; CI = 2·04 - ∞). No significant differences between breast and bottle-fed SIDS babies was observed in regard to each
Gait analysis of transfemoral amputees: errors in inverse dynamics are substantial and depend on prosthetic design.
Dumas, Raphael; Branemark, Rickard; Frossard, Laurent
Quantitative assessments of prostheses performances rely more and more frequently on gait analysis focusing on prosthetic knee joint forces and moments computed by inverse dynamics. However, this method is prone to errors, as demonstrated in comparison with direct measurements of these forces and moments. The magnitude of errors reported in the literature seems to vary depending on prosthetic components. Therefore, the purposes of this study were (A) to quantify and compare the magnitude of errors in knee joint forces and moments obtained with inverse dynamics and direct measurements on ten participants with transfemoral amputation during walking and (B) to investigate if these errors can be characterised for different prosthetic knees. Knee joint forces and moments computed by inverse dynamics presented substantial errors, especially during the swing phase of gait. Indeed, the median errors in percentage of the moment magnitude were 4% and 26% in extension/flexion, 6% and 19% in adduction/abduction as well as 14% and 27% in internal/external rotation during stance and swing phase, respectively. Moreover, errors varied depending on the prosthetic limb fitted with mechanical or microprocessorcontrolled knees. This study confirmed that inverse dynamics should be used cautiously while performing gait analysis of amputees. Alternatively, direct measurements of joint forces and moments could be relevant for mechanical characterising of components and alignments of prosthetic limbs.
ADEPT, a dynamic next generation sequencing data error-detection program with trimming
Feng, Shihai; Lo, Chien-Chi; Li, Po-E; ...
Illumina is the most widely used next generation sequencing technology and produces millions of short reads that contain errors. These sequencing errors constitute a major problem in applications such as de novo genome assembly, metagenomics analysis and single nucleotide polymorphism discovery. In this study, we present ADEPT, a dynamic error detection method, based on the quality scores of each nucleotide and its neighboring nucleotides, together with their positions within the read and compares this to the position-specific quality score distribution of all bases within the sequencing run. This method greatly improves upon other available methods in terms of the truemore » positive rate of error discovery without affecting the false positive rate, particularly within the middle of reads. We conclude that ADEPT is the only tool to date that dynamically assesses errors within reads by comparing position-specific and neighboring base quality scores with the distribution of quality scores for the dataset being analyzed. The result is a method that is less prone to position-dependent under-prediction, which is one of the most prominent issues in error prediction. The outcome is that ADEPT improves upon prior efforts in identifying true errors, primarily within the middle of reads, while reducing the false positive rate.« less
ADEPT, a dynamic next generation sequencing data error-detection program with trimming
Feng, Shihai; Lo, Chien-Chi; Li, Po-E; Chain, Patrick S. G.
Illumina is the most widely used next generation sequencing technology and produces millions of short reads that contain errors. These sequencing errors constitute a major problem in applications such as de novo genome assembly, metagenomics analysis and single nucleotide polymorphism discovery. In this study, we present ADEPT, a dynamic error detection method, based on the quality scores of each nucleotide and its neighboring nucleotides, together with their positions within the read and compares this to the position-specific quality score distribution of all bases within the sequencing run. This method greatly improves upon other available methods in terms of the true positive rate of error discovery without affecting the false positive rate, particularly within the middle of reads. We conclude that ADEPT is the only tool to date that dynamically assesses errors within reads by comparing position-specific and neighboring base quality scores with the distribution of quality scores for the dataset being analyzed. The result is a method that is less prone to position-dependent under-prediction, which is one of the most prominent issues in error prediction. The outcome is that ADEPT improves upon prior efforts in identifying true errors, primarily within the middle of reads, while reducing the false positive rate.
MUST: A Scalable Approach to Runtime Error Detection in MPI Programs
Hilbrich, T; Schulz, M; de Supinski, B R; Muller, M
The Message-Passing Interface (MPI) is large and complex. Therefore, programming MPI is error prone. Several MPI runtime correctness tools address classes of usage errors, such as deadlocks or nonportable constructs. To our knowledge none of these tools scales to more than about 100 processes. However, some of the current HPC systems use more than 100,000 cores and future systems are expected to use far more. Since errors often depend on the task count used, we need correctness tools that scale to the full system size. We present a novel framework for scalable MPI correctness tools to address this need. Our fine-grained, module-based approach supports rapid prototyping and allows correctness tools built upon it to adapt to different architectures and use cases. The design uses PnMPI to instantiate a tool from a set of individual modules. We present an overview of our design, along with first performance results for a proof of concept implementation.
Transcoding-Based Error-Resilient Video Adaptation for 3G Wireless Networks
NASA Astrophysics Data System (ADS)
Eminsoy, Sertac; Dogan, Safak; Kondoz, Ahmet M.
Transcoding is an effective method to provide video adaptation for heterogeneous internetwork video access and communication environments, which require the tailoring (i.e., repurposing) of coded video properties to channel conditions, terminal capabilities, and user preferences. This paper presents a video transcoding system that is capable of applying a suite of error resilience tools on the input compressed video streams while controlling the output rates to provide robust communications over error-prone and bandwidth-limited 3G wireless networks. The transcoder is also designed to employ a new adaptive intra-refresh algorithm, which is responsive to the detected scene activity inherently embedded into the video content and the reported time-varying channel error conditions of the wireless network. Comprehensive computer simulations demonstrate significant improvements in the received video quality performances using the new transcoding architecture without an extra computational cost.
Critical appraisal of quantitative PCR results in colorectal cancer research: can we rely on published qPCR results?
Dijkstra, J R; van Kempen, L C; Nagtegaal, I D; Bustin, S A
The use of real-time quantitative polymerase chain reaction (qPCR) in cancer research has become ubiquitous. The relative simplicity of qPCR experiments, which deliver fast and cost-effective results, means that each year an increasing number of papers utilizing this technique are being published. But how reliable are the published results? Since the validity of gene expression data is greatly dependent on appropriate normalisation to compensate for sample-to-sample and run-to-run variation, we have evaluated the adequacy of normalisation procedures in qPCR-based experiments. Consequently, we assessed all colorectal cancer publications that made use of qPCR from 2006 until August 2013 for the number of reference genes used and whether they had been validated. Using even these minimal evaluation criteria, the validity of only three percent (6/179) of the publications can be adequately assessed. We describe common errors, and conclude that the current state of reporting on qPCR in colorectal cancer research is disquieting. Extrapolated to the study of cancer in general, it is clear that the majority of studies using qPCR cannot be reliably assessed and that at best, the results of these studies may or may not be valid and at worst, pervasive incorrect normalisation is resulting in the wholesale publication of incorrect conclusions. This survey demonstrates that the existence of guidelines, such as MIQE, is necessary but not sufficient to address this problem and suggests that the scientific community should examine its responsibility and be aware of the implications of these findings for current and future research.
Errors, error detection, error correction and hippocampal-region damage: data and theories.
MacKay, Donald G; Johnson, Laura W
This review and perspective article outlines 15 observational constraints on theories of errors, error detection, and error correction, and their relation to hippocampal-region (HR) damage. The core observations come from 10 studies with H.M., an amnesic with cerebellar and HR damage but virtually no neocortical damage. Three studies examined the detection of errors planted in visual scenes (e.g., a bird flying in a fish bowl in a school classroom) and sentences (e.g., I helped themselves to the birthday cake). In all three experiments, H.M. detected reliably fewer errors than carefully matched memory-normal controls. Other studies examined the detection and correction of self-produced errors, with controls for comprehension of the instructions, impaired visual acuity, temporal factors, motoric slowing, forgetting, excessive memory load, lack of motivation, and deficits in visual scanning or attention. In these studies, H.M. corrected reliably fewer errors than memory-normal and cerebellar controls, and his uncorrected errors in speech, object naming, and reading aloud exhibited two consistent features: omission and anomaly. For example, in sentence production tasks, H.M. omitted one or more words in uncorrected encoding errors that rendered his sentences anomalous (incoherent, incomplete, or ungrammatical) reliably more often than controls. Besides explaining these core findings, the theoretical principles discussed here explain H.M.'s retrograde amnesia for once familiar episodic and semantic information; his anterograde amnesia for novel information; his deficits in visual cognition, sentence comprehension, sentence production, sentence reading, and object naming; and effects of aging on his ability to read isolated low frequency words aloud. These theoretical principles also explain a wide range of other data on error detection and correction and generate new predictions for future test.
Mars gravitational field estimation error
NASA Technical Reports Server (NTRS)
Compton, H. R.; Daniels, E. F.
The error covariance matrices associated with a weighted least-squares differential correction process have been analyzed for accuracy in determining the gravitational coefficients through degree and order five in the Mars gravitational potential junction. The results are presented in terms of standard deviations for the assumed estimated parameters. The covariance matrices were calculated by assuming Doppler tracking data from a Mars orbiter, a priori statistics for the estimated parameters, and model error uncertainties for tracking-station locations, the Mars ephemeris, the astronomical unit, the Mars gravitational constant (G sub M), and the gravitational coefficients of degrees six and seven. Model errors were treated by using the concept of consider parameters.
Stochastic Models of Human Errors
NASA Technical Reports Server (NTRS)
Elshamy, Maged; Elliott, Dawn M. (Technical Monitor)
Humans play an important role in the overall reliability of engineering systems. More often accidents and systems failure are traced to human errors. Therefore, in order to have meaningful system risk analysis, the reliability of the human element must be taken into consideration. Describing the human error process by mathematical models is a key to analyzing contributing factors. Therefore, the objective of this research effort is to establish stochastic models substantiated by sound theoretic foundation to address the occurrence of human errors in the processing of the space shuttle.
Error bounds in cascading regressions
Karlinger, M.R.; Troutman, B.M.
Cascading regressions is a technique for predicting a value of a dependent variable when no paired measurements exist to perform a standard regression analysis. Biases in coefficients of a cascaded-regression line as well as error variance of points about the line are functions of the correlation coefficient between dependent and independent variables. Although this correlation cannot be computed because of the lack of paired data, bounds can be placed on errors through the required properties of the correlation coefficient. The potential meansquared error of a cascaded-regression prediction can be large, as illustrated through an example using geomorphologic data. ?? 1985 Plenum Publishing Corporation.
Exploring the impact of forcing error characteristics on physically based snow simulations within a global sensitivity analysis framework
NASA Astrophysics Data System (ADS)
Raleigh, M. S.; Lundquist, J. D.; Clark, M. P.
Physically based models provide insights into key hydrologic processes but are associated with uncertainties due to deficiencies in forcing data, model parameters, and model structure. Forcing uncertainty is enhanced in snow-affected catchments, where weather stations are scarce and prone to measurement errors, and meteorological variables exhibit high variability. Hence, there is limited understanding of how forcing error characteristics affect simulations of cold region hydrology and which error characteristics are most important. Here we employ global sensitivity analysis to explore how (1) different error types (i.e., bias, random errors), (2) different error probability distributions, and (3) different error magnitudes influence physically based simulations of four snow variables (snow water equivalent, ablation rates, snow disappearance, and sublimation). We use the Sobol' global sensitivity analysis, which is typically used for model parameters but adapted here for testing model sensitivity to coexisting errors in all forcings. We quantify the Utah Energy Balance model's sensitivity to forcing errors with 1 840 000 Monte Carlo simulations across four sites and five different scenarios. Model outputs were (1) consistently more sensitive to forcing biases than random errors, (2) generally less sensitive to forcing error distributions, and (3) critically sensitive to different forcings depending on the relative magnitude of errors. For typical error magnitudes found in areas with drifting snow, precipitation bias was the most important factor for snow water equivalent, ablation rates, and snow disappearance timing, but other forcings had a more dominant impact when precipitation uncertainty was due solely to gauge undercatch. Additionally, the relative importance of forcing errors depended on the model output of interest. Sensitivity analysis can reveal which forcing error characteristics matter most for hydrologic modeling.
[Simulation on the restoration effect of soil moisture in alfalfa (Medicago sativa)-grain rotation system in semi-arid and drought-prone regions of Loess Plateau].
Wang, Xue-Chun; Li, Jun; Fang, Xin-Yu; Sun, Jian; Tahir, Muhammad Naveed
With the combination of field survey and EPIC modeling, this paper simulated the restoration effect of soil moisture in different alfalfa (Medicago sativa)-grain rotation systems in semi-arid and drought-prone regions of Loess Plateau. In perennial alfalfa field and in grain crop field after alfalfa, the correlation coefficients between the simulated and observed values of soil moisture content in 0-10 m layer were larger than 0.9 (P < 0.01), and their relative root mean square errors were between 0.05 and 0.16, with the relative errors less than 10%. The dynamic changes of the simulated soil moisture contents in different soil layers were consistent with those of the observed values. In the study regions, it was difficult for the restoration of soil moisture in the deep soil layers of alfalfa field. During the cultivation of alfalfa, the soil moisture content in the layers at 8-10 m depth should not be less than 5.7%. Considering the sustainable development of agricultural production, the appropriate cultivation duration of alfalfa should be 4-6 years and no more than 8 years. For the restoration of soil moisture after alfalfa cultivation in the study regions, the rotation system potato (Solanum tuberosum) --> potato --> spring wheat (Triticum aestivum) could be adopted, and alfalfa could be cultivated again after 32-33 years.
Aging transition by random errors
Sun, Zhongkui; Ma, Ning; Xu, Wei
In this paper, the effects of random errors on the oscillating behaviors have been studied theoretically and numerically in a prototypical coupled nonlinear oscillator. Two kinds of noises have been employed respectively to represent the measurement errors accompanied with the parameter specifying the distance from a Hopf bifurcation in the Stuart-Landau model. It has been demonstrated that when the random errors are uniform random noise, the change of the noise intensity can effectively increase the robustness of the system. While the random errors are normal random noise, the increasing of variance can also enhance the robustness of the system under certain conditions that the probability of aging transition occurs reaches a certain threshold. The opposite conclusion is obtained when the probability is less than the threshold. These findings provide an alternative candidate to control the critical value of aging transition in coupled oscillator system, which is composed of the active oscillators and inactive oscillators in practice. PMID:28198430
Robust characterization of leakage errors
NASA Astrophysics Data System (ADS)
Wallman, Joel J.; Barnhill, Marie; Emerson, Joseph
Leakage errors arise when the quantum state leaks out of some subspace of interest, for example, the two-level subspace of a multi-level system defining a computational 'qubit', the logical code space of a quantum error-correcting code, or a decoherence-free subspace. Leakage errors pose a distinct challenge to quantum control relative to the more well-studied decoherence errors and can be a limiting factor to achieving fault-tolerant quantum computation. Here we present a scalable and robust randomized benchmarking protocol for quickly estimating the leakage rate due to an arbitrary Markovian noise process on a larger system. We illustrate the reliability of the protocol through numerical simulations.
Static Detection of Disassembly Errors
Krishnamoorthy, Nithya; Debray, Saumya; Fligg, Alan K
Static disassembly is a crucial first step in reverse engineering executable files, and there is a consider- able body of work in reverse-engineering of binaries, as well as areas such as semantics-based security anal- ysis, that assumes that the input executable has been correctly disassembled. However, disassembly errors, e.g., arising from binary obfuscations, can render this assumption invalid. This work describes a machine- learning-based approach, using decision trees, for stat- ically identifying possible errors in a static disassem- bly; such potential errors may then be examined more closely, e.g., using dynamic analyses. Experimental re- sults using a variety of input executables indicate that our approach performs well, correctly identifying most disassembly errors with relatively few false positives.
Prospective errors determine motor learning
Takiyama, Ken; Hirashima, Masaya; Nozaki, Daichi
Diverse features of motor learning have been reported by numerous studies, but no single theoretical framework concurrently accounts for these features. Here, we propose a model for motor learning to explain these features in a unified way by extending a motor primitive framework. The model assumes that the recruitment pattern of motor primitives is determined by the predicted movement error of an upcoming movement (prospective error). To validate this idea, we perform a behavioural experiment to examine the model's novel prediction: after experiencing an environment in which the movement error is more easily predictable, subsequent motor learning should become faster. The experimental results support our prediction, suggesting that the prospective error might be encoded in the motor primitives. Furthermore, we demonstrate that this model has a strong explanatory power to reproduce a wide variety of motor-learning-related phenomena that have been separately explained by different computational models. PMID:25635628
Aging transition by random errors
NASA Astrophysics Data System (ADS)
Sun, Zhongkui; Ma, Ning; Xu, Wei
In this paper, the effects of random errors on the oscillating behaviors have been studied theoretically and numerically in a prototypical coupled nonlinear oscillator. Two kinds of noises have been employed respectively to represent the measurement errors accompanied with the parameter specifying the distance from a Hopf bifurcation in the Stuart-Landau model. It has been demonstrated that when the random errors are uniform random noise, the change of the noise intensity can effectively increase the robustness of the system. While the random errors are normal random noise, the increasing of variance can also enhance the robustness of the system under certain conditions that the probability of aging transition occurs reaches a certain threshold. The opposite conclusion is obtained when the probability is less than the threshold. These findings provide an alternative candidate to control the critical value of aging transition in coupled oscillator system, which is composed of the active oscillators and inactive oscillators in practice.
Interpolation Errors in Spectrum Analyzers
NASA Technical Reports Server (NTRS)
Martin, J. L.
To obtain the proper measurement amplitude with a spectrum analyzer, the correct frequency-dependent transducer factor must be added to the voltage measured by the transducer. This report examines how entering transducer factors into a spectrum analyzer can cause significant errors in field amplitude due to the misunderstanding of the analyzer's interpolation methods. It also discusses how to reduce these errors to obtain a more accurate field amplitude reading.
Does targeted pre-load optimisation by stroke volume variation attenuate a reduction in cardiac output in the prone position.
Wu, C-Y; Lee, T-S; Chan, K-C; Jeng, C-S; Cheng, Y-J
The prone position can reduce cardiac output by up to 25% due to reduced preload. We hypothesised that preload optimisation targeted to stroke volume variation before turning prone might alleviate this. A supine threshold stroke volume variation of 14% in a preliminary study identified patients whose cardiac outputs would decline when turned prone. In 45 patients, cardiac output declined only in the group whose supine stroke volume variation was high (mean (SD) 5.1 (2.0) to 3.9 (1.9) l.min(-1) ; p < 0.001), but not in patients in whom it was low, or in those in whom stroke volume variation was high, but who received volume preload (p = 0.525 and 0.941, respectively). We conclude that targeted preload optimisation using a supine stroke volume variation value < 14% is effective in preventing falls in cardiac output induced by the prone position.
Quantum error correction for beginners.
Devitt, Simon J; Munro, William J; Nemoto, Kae
Quantum error correction (QEC) and fault-tolerant quantum computation represent one of the most vital theoretical aspects of quantum information processing. It was well known from the early developments of this exciting field that the fragility of coherent quantum systems would be a catastrophic obstacle to the development of large-scale quantum computers. The introduction of quantum error correction in 1995 showed that active techniques could be employed to mitigate this fatal problem. However, quantum error correction and fault-tolerant computation is now a much larger field and many new codes, techniques, and methodologies have been developed to implement error correction for large-scale quantum algorithms. In response, we have attempted to summarize the basic aspects of quantum error correction and fault-tolerance, not as a detailed guide, but rather as a basic introduction. The development in this area has been so pronounced that many in the field of quantum information, specifically researchers who are new to quantum information or people focused on the many other important issues in quantum computation, have found it difficult to keep up with the general formalisms and methodologies employed in this area. Rather than introducing these concepts from a rigorous mathematical and computer science framework, we instead examine error correction and fault-tolerance largely through detailed examples, which are more relevant to experimentalists today and in the near future.
Error image aware content restoration
NASA Astrophysics Data System (ADS)
Choi, Sungwoo; Lee, Moonsik; Jung, Byunghee
As the resolution of TV significantly increased, content consumers have become increasingly sensitive to the subtlest defect in TV contents. This rising standard in quality demanded by consumers has posed a new challenge in today's context where the tape-based process has transitioned to the file-based process: the transition necessitated digitalizing old archives, a process which inevitably produces errors such as disordered pixel blocks, scattered white noise, or totally missing pixels. Unsurprisingly, detecting and fixing such errors require a substantial amount of time and human labor to meet the standard demanded by today's consumers. In this paper, we introduce a novel, automated error restoration algorithm which can be applied to different types of classic errors by utilizing adjacent images while preserving the undamaged parts of an error image as much as possible. We tested our method to error images detected from our quality check system in KBS(Korean Broadcasting System) video archive. We are also implementing the algorithm as a plugin of well-known NLE(Non-linear editing system), which is a familiar tool for quality control agent.
Dominant modes via model error
NASA Technical Reports Server (NTRS)
Yousuff, A.; Breida, M.
Obtaining a reduced model of a stable mechanical system with proportional damping is considered. Such systems can be conveniently represented in modal coordinates. Two popular schemes, the modal cost analysis and the balancing method, offer simple means of identifying dominant modes for retention in the reduced model. The dominance is measured via the modal costs in the case of modal cost analysis and via the singular values of the Gramian-product in the case of balancing. Though these measures do not exactly reflect the more appropriate model error, which is the H2 norm of the output-error between the full and the reduced models, they do lead to simple computations. Normally, the model error is computed after the reduced model is obtained, since it is believed that, in general, the model error cannot be easily computed a priori. The authors point out that the model error can also be calculated a priori, just as easily as the above measures. Hence, the model error itself can be used to determine the dominant modes. Moreover, the simplicity of the computations does not presume any special properties of the system, such as small damping, orthogonal symmetry, etc.
Smartphone addiction proneness in relation to sleep and morningness–eveningness in German adolescents
Randler, Christoph; Wolfgang, Lucia; Matt, Katharina; Demirhan, Eda; Horzum, Mehmet Barış; Beşoluk, Şenol
Background Mobile phones are an important part of adolescents' life. In this study, the relationships among smartphone addiction, age, gender, and chronotype of German adolescents were examined. Materials and methods Two studies focused on two different measures of smartphone addiction. The Smartphone Addiction Proneness Scale (SAPS) was applied to 342 younger adolescents (13.39 ± 1.77; 176 boys, 165 girls, and 1 not indicated) in Study 1 and the Smartphone Addiction Scale was applied to 208 older adolescents (17.07 ± 4.28; 146 girls and 62 boys) in Study 2, both samples in southwest Germany. In addition, a demographic questionnaire and the Composite Scale of Morningness (CSM) and sleep measures were implemented. Results The most remarkable result of this study was that morningness–eveningness (as measured by CSM scores) is an important predictor for smartphone addiction; even stronger than sleep duration. Evening oriented adolescents scored higher on both smartphone addiction scales. In addition, gender is an important predictor for smartphone addiction and girls are more prone to become addicted. In addition, while sleep duration on weekdays negatively predicted SAPS, age, sleep duration on weekends, and midpoint of sleep on weekdays and weekends did not predicted smartphone addiction in both scales. The analysis of covariance revealed statistically significant effects of the covariates gender and age in both studies, as well as the main effect of chronotype. According to the t-test results, girls had higher scores than boys in smartphone addiction. Conclusion Evening types and girls are more prone to become smartphone addicted. PMID:27499228
Influence Of Scapular Position On The Core Musculature Activation In The Prone Plank Exercise.
Cortell-Tormo, Juan M; García-Jaén, Miguel; Chulvi-Medrano, Iván; Hernández-Sánchez, Sergio; Lucas-Cuevas, Ángel G; Tortosa-Martínez, Juan
Prone plank is a widely used exercise in core stability training. Research has shown that pelvic tilt plays an important role on the electromyographical (EMG) activation of core musculature. However, the influence of scapular position on EMG activation is currently unknown. Therefore, this study evaluated the influence of scapular position on the core muscles during a prone plank. Surface electromyography of the rectus abdominis (RA), external oblique (EO), internal oblique (IO) and erector spinae (ES) was collected in fifteen participants (10 men, 5 women). Four variations of the prone plank were evaluated: scapular abduction with anterior (ABANT) and posterior (ABRET) pelvic tilt; and scapular adduction with anterior (ADANT) and posterior (ADRET) pelvic tilt. Individual muscle EMG and overall EMG for each plank exercise was analyzed. Joint positions were controlled with a 2D kinematic analysis. Ratings of perceived effort (RPE) were also registered. ADRET resulted in higher overall EMG activity compared to ABANT (p=0.04) and ADANT (p=0.04). Moreover, ADRET resulted in greater EMG activity compared to ADANT, ABANT, and ABRET for EO (p=0.000; p=0.000; p=0.035), IO (p=0.000; p=0.000; p=0.005) and ES (p=0.019; p=0.001; p=0.014). Regarding RA, ADRET was significantly higher compared to ADANT (p=0.002) and ABANT (p=0.005). Finally, ADRET provoked a higher RPE compared to ABANT (p=0.000), ABRET (p=0.001) and ADANT (p=0.015). These findings demonstrate the influence of the scapular and pelvic position on the EMG response of the core muscle groups analyzed in this study, and highlight the greater contribution of these muscles to the postural stabilizing demands during posterior pelvic tilt positions, particularly when the scapulae are in adduction.
On the retention of gene duplicates prone to dominant deleterious mutations.
Malaguti, Giulia; Singh, Param Priya; Isambert, Hervé
Recent studies have shown that gene families from different functional categories have been preferentially expanded either by small scale duplication (SSD) or by whole-genome duplication (WGD). In particular, gene families prone to dominant deleterious mutations and implicated in cancers and other genetic diseases in human have been greatly expanded through two rounds of WGD dating back from early vertebrates. Here, we strengthen this intriguing observation, showing that human oncogenes involved in different primary tumors have retained many WGD duplicates compared to other human genes. In order to rationalize this evolutionary outcome, we propose a consistent population genetics model to analyze the retention of SSD and WGD duplicates taking into account their propensity to acquire dominant deleterious mutations. We solve a deterministic haploid model including initial duplicated loci, their retention through sub-functionalization or their neutral loss-of-function or deleterious gain-of-function at one locus. Extensions to diploid genotypes are presented and population size effects are analyzed using stochastic simulations. The only difference between the SSD and WGD scenarios is the initial number of individuals with duplicated loci. While SSD duplicates need to spread through the entire population from a single individual to reach fixation, WGD duplicates are de facto fixed in the small initial post-WGD population arising through the ploidy incompatibility between post-WGD individuals and the rest of the pre-WGD population. WGD duplicates prone to dominant deleterious mutations are then shown to be indirectly selected through purifying selection in post-WGD species, whereas SSD duplicates typically require positive selection. These results highlight the long-term evolution mechanisms behind the surprising accumulation of WGD duplicates prone to dominant deleterious mutations and are shown to be consistent with cancer genome data on the prevalence of human
Quick Analysis Method for Estimating Debris Flow Prone Area Caused by Overflow from Landslide dam
NASA Astrophysics Data System (ADS)
Shimizu, T.; Uchida, T.; Yamakoshi, T.; Yoshino, K.; Kisa, H.; Ishizuka, T.; Kaji, A.
When earthquake or torrential rainfall cause deep catastrophic landslides, landslide dams can be formed in mountainous region. If water overflows from the landslide dams, large scale debris flow can occurs and possibly causes serious disasters in the downward region. Debris flow caused by the overflow from landslide dam is possible to affect the larger area than normal debris flow and flash flood. It is important for both a decision maker and resident in the area to recognize the disaster prone area as early as possible. For that reason, it is important to establish a quick analysis method for estimating debris flow prone area caused by overflow from landslide dams under the emergency situation. This situation requires the method to have both accuracy and speed for release. Nonetheless these two factors have trade-off relationship. We recently developed the quick analysis method to estimate debris flow disaster prone area caused by overflow from landslide dams. The method including the ways of efficient survey and numerical simulation programs called QUAD-L (QUick Analysis system for Debris flow caused by Landslide dam overflow). Our quick analysis system was actually applied to show the area for evacuation against debris flow caused by overflow from landslide dam formed by the 2011 Typhoon Talas which hit mainly the central region of Japan on September 2-4th, 2011. In addition to background of this application, since May 1st, 2011, Erosion and Sediment Control (SABO) Department of the Ministry of Land, Infrastructure, Transport and Tourism, Japan (MLIT) launched a new scheme using above-mentioned quick analysis method.
Smartphone addiction proneness in relation to sleep and morningness-eveningness in German adolescents.
Randler, Christoph; Wolfgang, Lucia; Matt, Katharina; Demirhan, Eda; Horzum, Mehmet Barış; Beşoluk, Şenol
Background Mobile phones are an important part of adolescents' life. In this study, the relationships among smartphone addiction, age, gender, and chronotype of German adolescents were examined. Materials and methods Two studies focused on two different measures of smartphone addiction. The Smartphone Addiction Proneness Scale (SAPS) was applied to 342 younger adolescents (13.39 ± 1.77; 176 boys, 165 girls, and 1 not indicated) in Study 1 and the Smartphone Addiction Scale was applied to 208 older adolescents (17.07 ± 4.28; 146 girls and 62 boys) in Study 2, both samples in southwest Germany. In addition, a demographic questionnaire and the Composite Scale of Morningness (CSM) and sleep measures were implemented. Results The most remarkable result of this study was that morningness-eveningness (as measured by CSM scores) is an important predictor for smartphone addiction; even stronger than sleep duration. Evening oriented adolescents scored higher on both smartphone addiction scales. In addition, gender is an important predictor for smartphone addiction and girls are more prone to become addicted. In addition, while sleep duration on weekdays negatively predicted SAPS, age, sleep duration on weekends, and midpoint of sleep on weekdays and weekends did not predicted smartphone addiction in both scales. The analysis of covariance revealed statistically significant effects of the covariates gender and age in both studies, as well as the main effect of chronotype. According to the t-test results, girls had higher scores than boys in smartphone addiction. Conclusion Evening types and girls are more prone to become smartphone addicted.
The contact allergen dinitrochlorobenzene (DNCB) and respiratory allergy in the Th2-prone Brown Norway rat.
Kuper, C Frieke; Stierum, Rob H; Boorsma, Andre; Schijf, Marcel A; Prinsen, Menk; Bruijntjes, Joost P; Bloksma, Nanne; Arts, Josje H E
All LMW respiratory allergens known to date can also induce skin allergy in test animals. The question here was if in turn skin allergens can induce allergy in the respiratory tract. Respiratory allergy was tested in Th2-prone Brown Norway (BN) rats by dermal sensitization with the contact allergen dinitrochlorobenzene (DNCB; 1%, day 0; 0.5%, day 7) and a head/nose-only inhalation challenge of 27mg/m3 of DNCB (15 min, day 21), using a protocol that successfully identified chemical respiratory allergens. Skin allergy to DNCB was examined in BN rats and Th1-prone Wistar rats in a local lymph node assay followed by a topical patch challenge of 0.1% DNCB. Sensitization of BN rats via the skin induced DNCB-specific IgG in serum, but not in all animals, and an increased number of CD4+ cells in the lung parenchyma. Subsequent inhalation challenge with DNCB did not provoke apneas or allergic inflammation (signs of respiratory allergy) in the BN rats. However, microarray analysis of mRNA isolated from the lung revealed upregulation of the genes for Ccl2 (MCP-1), Ccl4 (MIP-1beta), Ccl7 and Ccl17. Skin challenge induced considerably less skin irritation and allergic dermatitis in the BN rat than in the Wistar rat. In conclusion, the Th2-prone BN rat appeared less sensitive to DNCB than the Wistar rat; nevertheless, DNCB induced allergic inflammation in the skin of BN rats but even a relatively high challenge concentration did not induce allergy in the respiratory tract, although genes associated with allergy were upregulated in lung tissue.
Accelerated Whole Breast Irradiation With Intensity-Modulated Radiotherapy to the Prone Breast
Croog, Victoria J.; Wu, Abraham J.; McCormick, Beryl; Beal, Kathryn P.
Purpose: Whole breast irradiation (WBI) is the standard of care for patients with early-stage breast cancer who opt for breast conservation. After a randomized trial demonstrated equivalent cosmesis and disease control with accelerated WBI (AWBI), our institution began to offer AWBI to appropriate patients. The aim of this study was to examine our unique experience with AWBI using prone positioning and simplified intensity-modulated radiotherapy (IMRT) planning with a sequential boost to the tumor bed. Methods and Materials: We identified 356 patients who had been treated with prone WBI using IMRT in our department between January 2004 and December 2006. Of these, 128 (36%) patients had received AWBI (representing 131 treated breasts), consisting of 16 daily fractions of 265 cGy to a total dose of 4,240 cGy followed by a conventionally fractionated boost. Results: Patients who opted for AWBI were similar demographically to the patients undergoing conventional WBI. In the AWBI cohort, 83% of the patients had Stage T1 disease and 22% had nodal involvement (N1). The tumors were estrogen receptor-positive, progesterone receptor-positive and Her-2/Neu-amplified in 82%, 69%, and 11%, respectively. The median duration of AWBI plus a boost was 29 days, and no patient required a toxicity-related treatment break. No Grade 3 or greater acute toxicity developed. At a median follow-up of 18 months, one ipsilateral breast recurrence developed that was salvaged with mastectomy and immediate reconstruction. Conclusion: AWBI to the prone breast using simplified IMRT with a sequential boost offers women requiring breast-only adjuvant radiotherapy an abbreviated treatment with early tumor control and cosmesis comparable to that with standard fractionation.
Nanomaterial Containing Wall Paints Can Increase Radon Concentration in Houses Located in Radon Prone Areas
Haghani, M.; Mortazavi, S. M. J.; Faghihi, R.; Mehdizadeh, S.; Moradgholi, J.; Darvish, L.; Fathi-Pour, E.; Ansari, L.; Ghanbar-pour, M. R.
Background: Nowadays, extensive technological advancements have made it possible to use nanopaints which show exciting properties. In IR Iran excessive radon levels (up to 3700 Bq m–3) have been reported in homes located in radon prone areas. Over the past decades, concerns have been raised about the risk posed by residential radon exposure. Objective: This study aims at investigating the effect of using nanomaterial containing wall paints on radon concentration in homes. Methods: Two wooden model houses were used in this study. Soil samples from Ramsar high background radiation areas were used for simulating the situation of a typical house in radon-prone areas. Conventional water-soluble wall paint was used for painting the walls of the 1st house model; while the 2nd house model was painted with the same wall paint with montmorillonitenanoclay. Results: Three days after sealing the house models, radon level was measured by using a portable radon survey meter. The mean radon level inside the 1st house model (conventional paint) was 515.3 ± 17.8 Bq/m3 while the mean radon concentration in the 2nd house model (nano-painted house model) was 570.8 ± 18.5 Bq/m3. The difference between these means was statistically significant (P<0.001). Conclusion: To the best of our knowledge, this study is the first investigation on the effect of nano-material containing wall paints on indoor radon concentrations. It can be concluded that nano-material-containing wall paints should not be used in houses with wooden walls located in radon prone areas. Although the mechanism of this effect is not clearly known, decreased porosity in nano-paints might be a key factor in increasing the radon concentration in homes. PMID:25505754
Excessive daydreaming: a case history and discussion of mind wandering and high fantasy proneness.
Schupak, Cynthia; Rosenthal, Jesse
This case study describes a patient presenting with a long history of excessive daydreaming which has caused her distress but is not incident to any other apparent clinical psychiatric disorders. We have treated this patient for over 10 years, and she has responded favorably to fluvoxamine therapy, stating that it helps to control her daydreaming. Our patient, and other psychotherpists, have brought to our attention other possible cases of excessive daydreaming. We examine the available literature regarding daydreaming, mind wandering, and fantasy proneness relative to current cognitive and neuroanatomical models of executive attention.
Correlates of the multidimensional construct of hypnotizability: paranormal belief, fantasy proneness, magical ideation, and dissociation.
Dasse, Michelle N; Elkins, Gary R; Weaver, Charles A
Hypnotizability is a multifaceted construct that may relate to multiple aspects of personality and beliefs. This study sought to address 4 known correlates of hypnotizability to aid in its understanding. Eighty undergraduates completed the Magical Ideation Scale (MIS), the Creative Experiences Questionnaire (CEQ), the Australian Sheep-Goat Scale (ASGS), and the Dissociative Experiences Scale (DES) and then were administered the Creative Imagination Scale (CIS). All 5 scales were significantly correlated. Participants higher in hypnotizability scored higher on the CEQ and the MIS. The findings demonstrate the influence of fantasy proneness and magical thinking on hypnotizability and support the theory that hypnotizability is a complex interaction of multiple traits.
Crisis Management of Accidental Extubation in a Prone-Positioned Patient with Klippel-Feil Syndrome.
Spond, Matthew; Burns, Tyler; Rosenbaum, Thea; Lienhart, Kristen
We present the case of an accidental extubation in a prone-positioned patient with a challenging airway because of Klippel-Feil syndrome and previous cervical spine fusions. The surgical procedure was well underway when this occurred, which added substantially to the difficulties produced by this event. We herein highlight the corrective steps we took in our case. We also recommend the need for a comprehensive preoperative briefing with all operating room personnel together with an action plan for how to prevent this particular scenario.
Short-term absence from industry: III The inference of `proneness' and a search for causes
Froggatt, P.
Froggatt, P. (1970).Brit. J. industr. Med.,27, 297-312. Short-term absence from industry. III. The inference of `proneness' and a search for causes. The abilities of five hypotheses (`chance', `proneness', and three of `true contagion' - as defined in the text) to explain the distributions of one-day and two-day absences among groups of male and female industrial personnel and clerks in government service are examined by curve-fitting and correlation methods. The five hypotheses generate (in order) the Poisson, negative binomial, Neyman type A, Short, and Hermite (two-parameter form) distributions which are fitted to the data using maximum-likelihood estimates. The conclusion is drawn that `proneness', i.e., a stable `liability', compounded from several though unquantifiable factors, and constant for each individual over the period of the study, is markedly successful in explaining the data. It is emphasized that some of the other hypotheses under test cannot be unequivocably rejected; and there is in theory an infinite number, still unformulated or untested, which may be acceptable or even fit the data better. Correlation coefficients for the numbers of one-day (and two-day) absences taken by the same individuals in two equal non-overlapping periods of time are of the order 0·5 to 0·7 (0·3 to 0·5 for two-day absences) and the corresponding regressions fulfil linear requirements. These correlations are higher than any between `personal characteristics' and their overt consequence in contingent fields of human enquiry. For one-day absences the predictive power for the future from the past record could in some circumstances justify executive action. When freely available, overtime was greatest among junior married men and least among junior married women. The validity of the inference of `proneness' and the implications of its acceptance are fully discussed. While interpretation is not unequivocal, one-day absences seemingly have many causes; two-day absences are
On the relationship between meaning in life and boredom proneness: examining a logotherapy postulate.
Melton, Amanda M A; Schulenberg, Stefan E
Logotherapy, developed by Viktor Frankl, posits that when one lacks meaning in life, boredom can result. Thus, the two constructs should be inversely related. To examine this relationship, 279 students (M = 19.8 yr., SD = 2.6; 179 women, 98 men) from a university in the southern United States were administered the Purpose of Life test and the Boredom Proneness Scale. As expected, a statistically significant negative correlation was found between the scores on the two scales (r = -.71). Directions for research are offered.
Holding Back the Tears: Individual Differences in Adult Crying Proneness Reflect Attachment Orientation and Attitudes to Crying.
Millings, Abigail; Hepper, Erica G; Hart, Claire M; Swift, Louise; Rowe, Angela C
Despite being a universal human attachment behavior, little is known about individual differences in crying. To facilitate such examination we first recommend shortened versions of the attitudes and proneness sections of the Adult Crying Inventory using two independent samples. Importantly, we examine attachment orientation differences in crying proneness and test the mediating role of attitudes toward crying in this relationship. Participants (Sample 1 N = 623, Sample 2 N = 781), completed online measures of adult attachment dimensions (avoidance and anxiety), attitudes toward crying, and crying proneness. Exploratory factor analyses in Sample 1 revealed four factors for crying attitudes: crying helps one feel better; crying is healthy; hatred of crying; and crying is controllable; and three factors for crying proneness: threat to self; sadness; and joy. Confirmatory factor analyses in Sample 2 replicated these structures. Theoretically and statistically justified short forms of each scale were created. Multiple mediation analyses revealed similar patterns of results across the two samples, with the attitudes "crying is healthy" and "crying is controllable" consistently mediating the positive links between attachment anxiety and crying proneness, and the negative links between attachment avoidance and crying proneness. Results are discussed in relation to attachment and emotion regulation literature.
Holding Back the Tears: Individual Differences in Adult Crying Proneness Reflect Attachment Orientation and Attitudes to Crying
Millings, Abigail; Hepper, Erica G.; Hart, Claire M.; Swift, Louise; Rowe, Angela C.
Despite being a universal human attachment behavior, little is known about individual differences in crying. To facilitate such examination we first recommend shortened versions of the attitudes and proneness sections of the Adult Crying Inventory using two independent samples. Importantly, we examine attachment orientation differences in crying proneness and test the mediating role of attitudes toward crying in this relationship. Participants (Sample 1 N = 623, Sample 2 N = 781), completed online measures of adult attachment dimensions (avoidance and anxiety), attitudes toward crying, and crying proneness. Exploratory factor analyses in Sample 1 revealed four factors for crying attitudes: crying helps one feel better; crying is healthy; hatred of crying; and crying is controllable; and three factors for crying proneness: threat to self; sadness; and joy. Confirmatory factor analyses in Sample 2 replicated these structures. Theoretically and statistically justified short forms of each scale were created. Multiple mediation analyses revealed similar patterns of results across the two samples, with the attitudes "crying is healthy" and "crying is controllable" consistently mediating the positive links between attachment anxiety and crying proneness, and the negative links between attachment avoidance and crying proneness. Results are discussed in relation to attachment and emotion regulation literature. PMID:27458402
PCR hot-start using duplex primers.
Kong, Deming; Shen, Hanxi; Huang, Yanping; Mi, Huaifeng
A new technique of PCR hot-start using duplex primers has been developed which can decrease the undesirable products arising throughout PCR amplification thereby giving better results than a manual hot-start method.
Single-stranded DNA oligomers stimulate error-prone alternative repair of DNA double-strand breaks through hijacking Ku protein
Yuan, Ying; Britton, Sébastien; Delteil, Christine; Coates, Julia; Jackson, Stephen P.; Barboule, Nadia; Frit, Philippe; Calsou, Patrick
In humans, DNA double-strand breaks (DSBs) are repaired by two mutually-exclusive mechanisms, homologous recombination or end-joining. Among end-joining mechanisms, the main process is classical non-homologous end-joining (C-NHEJ) which relies on Ku binding to DNA ends and DNA Ligase IV (Lig4)-mediated ligation. Mostly under Ku- or Lig4-defective conditions, an alternative end-joining process (A-EJ) can operate and exhibits a trend toward microhomology usage at the break junction. Homologous recombination relies on an initial MRN-dependent nucleolytic degradation of one strand at DNA ends. This process, named DNA resection generates 3′ single-stranded tails necessary for homologous pairing with the sister chromatid. While it is believed from the current literature that the balance between joining and recombination processes at DSBs ends is mainly dependent on the initiation of resection, it has also been shown that MRN activity can generate short single-stranded DNA oligonucleotides (ssO) that may also be implicated in repair regulation. Here, we evaluate the effect of ssO on end-joining at DSB sites both in vitro and in cells. We report that under both conditions, ssO inhibit C-NHEJ through binding to Ku and favor repair by the Lig4-independent microhomology-mediated A-EJ process. PMID:26350212
The error-prone DNA polymerase zeta catalytic subunit (Rev3) gene is ubiquitously expressed in normal and malignant human tissues.
Kawamura, K; O-Wang, J; Bahar, R; Koshikawa, N; Shishikura, T; Nakagawara, A; Sakiyama, S; Kajiwara, K; Kimura, M; Tagawa, M
Mutagenesis induced by UV light and chemical agents in yeast is largely dependent on the function of Rev3, the catalytic subunit of DNA polymerase zeta that carries out translesion DNA synthesis. Human and mouse homologues of the yeast Rev3 gene have recently been identified, and inhibition of Rev3 expression in cultured human fibroblasts by Rev3 anti-sense was shown to reduce UV-induced mutagenesis, indicating that Rev3 also plays a crucial role in mutagenesis in mammalian cells. A common variant transcript with an insertion of 128-bp between nucleotides +139 and +140 is found in both human and mouse Rev3 cDNAs, but its biological significance has not been defined. We show here that the insertion variant is not translatable either under in vitro or in vivo conditions. We also found that the translational efficiency of Rev3 gene is enhanced by the 5' untranslated region that contains a putative stem-loop structure postulated to inhibit the translation. Since the human Rev3 gene is localized to chromosome 6q21, a region previously shown to contain genes involved in tumor suppression and cellular senescence, we examined its expression in various normal and malignant tissues. Rev3 and its insertion variant transcripts were ubiquitously detected in all 27 normal human tissues studied, with an additional variant species found in tissues with relatively high levels of Rev3 expression. Levels of Rev3 transcripts were similar in lung, gastric, colon and renal tumors compared to normal tissue counterparts. The data indicate that Rev3 expression is ubiquitous and is not dysregulated in malignancies.
Mice expressing an error-prone DNA polymerase in mitochondria display elevated replication pausing and chromosomal breakage at fragile sites of mitochondrial DNA
Bailey, Laura J.; Cluett, Tricia J.; Reyes, Aurelio; Prolla, Tom A.; Poulton, Joanna; Leeuwenburgh, Christiaan; Holt, Ian J.
Expression of a proof-reading deficient form of mitochondrial DNA (mtDNA) polymerase γ, POLG, causes early death accompanied by features of premature ageing in mouse. However, the mechanism of cellular senescence remains unresolved. In addition to high levels of point mutations of mtDNA, the POLG mutator mouse harbours linear mtDNAs. Using one- and two-dimensional agarose gel electrophoresis, we show that the linear mtDNAs derive from replication intermediates and are indicative of replication pausing and chromosomal breakage at the accompanying fragile sites. Replication fork arrest is not random but occurs at specific sites close to two cis-elements known as OH and OL. Pausing at these sites may be enhanced in the case of exonuclease-deficient POLG owing to delayed resumption of DNA replication, or replisome instability. In either case, the mtDNA replication cycle is perturbed and this might explain the progeroid features of the POLG mutator mouse. PMID:19244310
MutS regulates access of the error-prone DNA polymerase Pol IV to replication sites: a novel mechanism for maintaining replication fidelity
Margara, Lucía M.; Fernández, Marisa M.; Malchiodi, Emilio L.; Argaraña, Carlos E.; Monti, Mariela R.
Translesion DNA polymerases (Pol) function in the bypass of template lesions to relieve stalled replication forks but also display potentially deleterious mutagenic phenotypes that contribute to antibiotic resistance in bacteria and lead to human disease. Effective activity of these enzymes requires association with ring-shaped processivity factors, which dictate their access to sites of DNA synthesis. Here, we show for the first time that the mismatch repair protein MutS plays a role in regulating access of the conserved Y-family Pol IV to replication sites. Our biochemical data reveals that MutS inhibits the interaction of Pol IV with the β clamp processivity factor by competing for binding to the ring. Moreover, the MutS–β clamp association is critical for controlling Pol IV mutagenic replication under normal growth conditions. Thus, our findings reveal important insights into a non-canonical function of MutS in the regulation of a replication activity. PMID:27257069
Comparison of prone versus supine 18F-FDG-PET of locally advanced breast cancer: Phantom and preliminary clinical studies
Williams, Jason M.; Rani, Sudheer D.; Li, Xia; Whisenant, Jennifer G.; Abramson, Richard G.; Arlinghaus, Lori R.; Lee, Tzu-Cheng; MacDonald, Lawrence R.; Partridge, Savannah C.; Kang, Hakmook; Linden, Hannah M.; Kinahan, Paul E.; Yankeelov, Thomas E.
Purpose: Previous studies have demonstrated how imaging of the breast with patients lying prone using a supportive positioning device markedly facilitates longitudinal and/or multimodal image registration. In this contribution, the authors' primary objective was to determine if there are differences in the standardized uptake value (SUV) derived from [{sup 18}F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in breast tumors imaged in the standard supine position and in the prone position using a specialized positioning device. Methods: A custom positioning device was constructed to allow for breast scanning in the prone position. Rigid and nonrigid phantom studies evaluated differences in prone and supine PET. Clinical studies comprised 18F-FDG-PET of 34 patients with locally advanced breast cancer imaged in the prone position (with the custom support) followed by imaging in the supine position (without the support). Mean and maximum values (SUV{sub peak} and SUV{sub max}, respectively) were obtained from tumor regions-of-interest for both positions. Prone and supine SUV were linearly corrected to account for the differences in 18F-FDG uptake time. Correlation, Bland–Altman, and nonparametric analyses were performed on uptake time-corrected and uncorrected data. Results: SUV from the rigid PET breast phantom imaged in the prone position with the support device was 1.9% lower than without the support device. In the nonrigid PET breast phantom, prone SUV with the support device was 5.0% lower than supine SUV without the support device. In patients, the median (range) difference in uptake time between prone and supine scans was 16.4 min (13.4–30.9 min), which was significantly—but not completely—reduced by the linear correction method. SUV{sub peak} and SUV{sub max} from prone versus supine scans were highly correlated, with concordance correlation coefficients of 0.91 and 0.90, respectively. Prone SUV{sub peak} and SUV{sub max} were
Palatal Dysmorphogenesis : Quantitative RT-PCR
Gary A. Held and Barbara D. Abbott
Reverse transcription PCR (RT-PCR) is a very sensitive method for detecting mRNA in tissue samples. However, as it is usually performed it is does not yield quantitativ...
Error-associated behaviors and error rates for robotic geology
NASA Technical Reports Server (NTRS)
Anderson, Robert C.; Thomas, Geb; Wagner, Jacob; Glasgow, Justin
This study explores human error as a function of the decision-making process. One of many models for human decision-making is Rasmussen's decision ladder [9]. The decision ladder identifies the multiple tasks and states of knowledge involved in decision-making. The tasks and states of knowledge can be classified by the level of cognitive effort required to make the decision, leading to the skill, rule, and knowledge taxonomy (Rasmussen, 1987). Skill based decisions require the least cognitive effort and knowledge based decisions require the greatest cognitive effort. Errors can occur at any of the cognitive levels.
Integrating a calibrated groundwater flow model with error-correcting data-driven models to improve predictions
NASA Astrophysics Data System (ADS)
Demissie, Yonas K.; Valocchi, Albert J.; Minsker, Barbara S.; Bailey, Barbara A.
SummaryPhysically-based groundwater models (PBMs), such as MODFLOW, contain numerous parameters which are usually estimated using statistically-based methods, which assume that the underlying error is white noise. However, because of the practical difficulties of representing all the natural subsurface complexity, numerical simulations are often prone to large uncertainties that can result in both random and systematic model error. The systematic errors can be attributed to conceptual, parameter, and measurement uncertainty, and most often it can be difficult to determine their physical cause. In this paper, we have developed a framework to handle systematic error in physically-based groundwater flow model applications that uses error-correcting data-driven models (DDMs) in a complementary fashion. The data-driven models are separately developed to predict the MODFLOW head prediction errors, which were subsequently used to update the head predictions at existing and proposed observation wells. The framework is evaluated using a hypothetical case study developed based on a phytoremediation site at the Argonne National Laboratory. This case study includes structural, parameter, and measurement uncertainties. In terms of bias and prediction uncertainty range, the complementary modeling framework has shown substantial improvements (up to 64% reduction in RMSE and prediction error ranges) over the original MODFLOW model, in both the calibration and the verification periods. Moreover, the spatial and temporal correlations of the prediction errors are significantly reduced, thus resulting in reduced local biases and structures in the model prediction errors.
Correcting for Measurement Error in Time-Varying Covariates in Marginal Structural Models.
Kyle, Ryan P; Moodie, Erica E M; Klein, Marina B; Abrahamowicz, Michał
Unbiased estimation of causal parameters from marginal structural models (MSMs) requires a fundamental assumption of no unmeasured confounding. Unfortunately, the time-varying covariates used to obtain inverse probability weights are often error-prone. Although substantial measurement error in important confounders is known to undermine control of confounders in conventional unweighted regression models, this issue has received comparatively limited attention in the MSM literature. Here we propose a novel application of the simulation-extrapolation (SIMEX) procedure to address measurement error in time-varying covariates, and we compare 2 approaches. The direct approach to SIMEX-based correction targets outcome model parameters, while the indirect approach corrects the weights estimated using the exposure model. We assess the performance of the proposed methods in simulations under different clinically plausible assumptions. The simulations demonstrate that measurement errors in time-dependent covariates may induce substantial bias in MSM estimators of causal effects of time-varying exposures, and that both proposed SIMEX approaches yield practically unbiased estimates in scenarios featuring low-to-moderate degrees of error. We illustrate the proposed approach in a simple analysis of the relationship between sustained virological response and liver fibrosis progression among persons infected with hepatitis C virus, while accounting for measurement error in γ-glutamyltransferase, using data collected in the Canadian Co-infection Cohort Study from 2003 to 2014.
A Digital PCR-Based Method for Efficient and Highly Specific Screening of Genome Edited Cells
Berman, Jennifer R.; Postovit, Lynne-Marie
The rapid adoption of gene editing tools such as CRISPRs and TALENs for research and eventually therapeutics necessitates assays that can rapidly detect and quantitate the desired alterations. Currently, the most commonly used assay employs "mismatch nucleases" T7E1 or "Surveyor" that recognize and cleave heteroduplexed DNA amplicons containing mismatched base-pairs. However, this assay is prone to false positives due to cancer-associated mutations and/or SNPs and requires large amounts of starting material. Here we describe a powerful alternative wherein droplet digital PCR (ddPCR) can be used to decipher homozygous from heterozygous mutations with superior levels of both precision and sensitivity. We use this assay to detect knockout inducing alterations to stem cell associated proteins, NODAL and SFRP1, generated using either TALENs or an "all-in-one" CRISPR/Cas plasmid that we have modified for one-step cloning and blue/white screening of transformants. Moreover, we highlight how ddPCR can be used to assess the efficiency of varying TALEN-based strategies. Collectively, this work highlights how ddPCR-based screening can be paired with CRISPR and TALEN technologies to enable sensitive, specific, and streamlined approaches to gene editing and validation. PMID:27089539
SU-E-J-227: Breathing Pattern Consistency and Reproducibility: Comparative Analysis for Supine and Prone Body Positioning
Laugeman, E; Weiss, E; Chen, S; Hugo, G; Rosu, M
Purpose: Evaluate and compare the cycle-to-cycle consistency of breathing patterns and their reproducibility over the course of treatment, for supine and prone positioning. Methods: Respiratory traces from 25 patients were recorded for sequential supine/prone 4DCT scans acquired prior to treatment, and during the course of the treatment (weekly or bi-weekly). For each breathing cycle, the average(AVE), end-of-exhale(EoE) and end-of-inhale( EoI) locations were identified using in-house developed software. In addition, the mean values and variations for the above quantities were computed for each breathing trace. F-tests were used to compare the cycle-to-cycle consistency of all pairs of sequential supine and prone scans. Analysis of variances was also performed using population means for AVE, EoE and EoI to quantify differences between the reproducibility of prone and supine respiration traces over the treatment course. Results: Consistency: Cycle-to-cycle variations are less in prone than supine in the pre-treatment and during-treatment scans for AVE, EoE and EoI points, for the majority of patients (differences significant at p<0.05). The few cases where the respiratory pattern had more variability in prone appeared to be random events. Reproducibility: The reproducibility of breathing patterns (supine and prone) improved as treatment progressed, perhaps due to patients becoming more comfortable with the procedure. However, variability in supine position continued to remain significantly larger than in prone (p<0.05), as indicated by the variance analysis of population means for the pretreatment and subsequent during-treatment scans. Conclusions: Prone positioning stabilizes breathing patterns in most subjects investigated in this study. Importantly, a parallel analysis of the same group of patients revealed a tendency towards increasing motion amplitude of tumor targets in prone position regardless of their size or location; thus, the choice for body positioning
Genome-wide profiling of yeast DNA:RNA hybrid prone sites with DRIP-chip.
Chan, Yujia A; Aristizabal, Maria J; Lu, Phoebe Y T; Luo, Zongli; Hamza, Akil; Kobor, Michael S; Stirling, Peter C; Hieter, Philip
DNA:RNA hybrid formation is emerging as a significant cause of genome instability in biological systems ranging from bacteria to mammals. Here we describe the genome-wide distribution of DNA:RNA hybrid prone loci in Saccharomyces cerevisiae by DNA:RNA immunoprecipitation (DRIP) followed by hybridization on tiling microarray. These profiles show that DNA:RNA hybrids preferentially accumulated at rDNA, Ty1 and Ty2 transposons, telomeric repeat regions and a subset of open reading frames (ORFs). The latter are generally highly transcribed and have high GC content. Interestingly, significant DNA:RNA hybrid enrichment was also detected at genes associated with antisense transcripts. The expression of antisense-associated genes was also significantly altered upon overexpression of RNase H, which degrades the RNA in hybrids. Finally, we uncover mutant-specific differences in the DRIP profiles of a Sen1 helicase mutant, RNase H deletion mutant and Hpr1 THO complex mutant compared to wild type, suggesting different roles for these proteins in DNA:RNA hybrid biology. Our profiles of DNA:RNA hybrid prone loci provide a resource for understanding the properties of hybrid-forming regions in vivo, extend our knowledge of hybrid-mitigating enzymes, and contribute to models of antisense-mediated gene regulation. A summary of this paper was presented at the 26th International Conference on Yeast Genetics and Molecular Biology, August 2013.
Triage of oxidation-prone proteins by Sqstm1/p62 within the mitochondria
Lee, Minjung; Shin, Jaekyoon
Highlights: {yields} The mitochondrion contains its own protein quality control system. {yields} p62 localizes within the mitochondria and forms mega-dalton sized complexes. {yields} p62 interacts with oxidation-prone proteins and the proteins of quality control. {yields} In vitro delivery of p62 improves mitochondrial functions. {yields} p62 is implicated as a participant in mitochondrial protein quality control. -- Abstract: As the mitochondrion is vulnerable to oxidative stress, cells have evolved several strategies to maintain mitochondrial integrity, including mitochondrial protein quality control mechanisms and autophagic removal of damaged mitochondria. Involvement of an autophagy adaptor, Sqstm1/p62, in the latter process has been recently described. In the present study, we provide evidence that a portion of p62 directly localizes within the mitochondria and supports stable electron transport by forming heterogeneous protein complexes. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) of mitochondrial proteins co-purified with p62 revealed that p62 interacts with several oxidation-prone proteins, including a few components of the electron transport chain complexes, as well as multiple chaperone molecules and redox regulatory enzymes. Accordingly, p62-deficient mitochondria exhibited compromised electron transport, and the compromised function was partially restored by in vitro delivery of p62. These results suggest that p62 plays an additional role in maintaining mitochondrial integrity at the vicinity of target machineries through its function in relation to protein quality control.
Absence of food alternatives promotes risk-prone feeding of unpalatable substances in honey bees.
Desmedt, Lucie; Hotier, Lucie; Giurfa, Martin; Velarde, Rodrigo; de Brito Sanchez, Maria Gabriela
The question of why animals sometimes ingest noxious substances is crucial to understand unknown determinants of feeding behaviour. Research on risk-prone feeding behaviour has largely focused on energy budgets as animals with low energy budgets tend to ingest more aversive substances. A less explored possibility is that risk-prone feeding arises from the absence of alternative feeding options, irrespectively of energy budgets. Here we contrasted these two hypotheses in late-fall and winter honey bees. We determined the toxicity of various feeding treatments and showed that when bees can choose between sucrose solution and a mixture of this sucrose solution and a noxious/unpalatable substance, they prefer the pure sucrose solution and reject the mixtures, irrespective of their energy budget. Yet, when bees were presented with a single feeding option and their escape possibilities were reduced, they consumed unexpectedly some of the previously rejected mixtures, independently of their energy budget. These findings are interpreted as a case of feeding helplessness, in which bees behave as if it were utterly helpless to avoid the potentially noxious food and consume it. They suggest that depriving bees of variable natural food sources may have the undesired consequence of increasing their acceptance of food that would be otherwise rejected.
The challenges of trafficking hydrolysis prone metals and ascidians as an archetype.
Gaffney, Jean P; Valentine, Ann M
Some of the metal ions that are required, exploited, or simply managed in biological systems are susceptible to hydrolysis and to hydrolytic precipitation in the aqueous, aerobic environment of much of biology. Organisms have evolved exquisite mechanisms for handling these metal ions, offering striking examples of biological control over inorganic coordination chemistry. This year marks the one hundredth anniversary of the discovery of remarkably high vanadium concentrations in the blood cells of the ascidian. In the ensuing years, these marine invertebrates were established as masters of the biological chemistry of very hydrolysis-prone metals, with various ascidian species accumulating high concentrations of iron, vanadium, and titanium, among others. These three metals have very different histories of biological relevance, and many questions remain about how, and ultimately why, these organisms sequester them. This Perspective addresses the aqueous coordination chemistry that organisms like ascidians must control if they are to manipulate hydrolysis-prone metal ions, and describes some of the ascidian biomolecules that have been implicated in this phenomenon. The recently available genome sequence for one ascidian species offers a glimpse into its metal-management arsenal. It offers the opportunity to map the relatively well-studied paradigm of iron management onto the genome of an organism that is intermediate in evolution between invertebrates and vertebrates. The ascidians have much to teach us about how to manage metals like iron, titanium, and vanadium and how that ability evolved.
Greater trochanter location measurement using a three-dimensional motion capture system during prone hip extension
Yu, Ji-Su; Oh, Jae-Seop
[Purpose] The greater trochanter (GT) is an important structure in biomedical research, but the measurement methods require development. This study presents data from a new measurement method that does not use GT-marker-based measurement (No GT-m) in comparison with GT-marker based measurement (GT-m). [Subjects and Methods] We recruited 20 healthy subjects, who were asked to perform and maintain a prone position and then move to the prone hip extension. A motion capture system collected the kinematic data and the location of the GT was calculated by two measurements. [Results] GT migration distance differed significantly between the two measurements and the coefficient of the variation value was lower for the No GT-m method. Thigh lengths of the No GT-m method were comparable to the original lengths. There were significant differences between the GT-m and the other methods. [Conclusions] These data suggest that the GT-m method yielded a lower precision with a smaller GT migration distance. In the comparison of thigh length, the No GT-m method was in close agreement with the original length. We suggest that determining the location of the GT using the No GT-m has greater accuracy than the GT-m method. PMID:28265151
Use of thermal inertia determined by HCMM to predict nocturnal cold prone areas in Florida
NASA Technical Reports Server (NTRS)
Allen, L. H., Jr. (Principal Investigator)
Pairs of HCMM day-night thermal infrared (IR) data were selected during the 1978-79 winter to examine patterns of surface temperature and thermal inertia (TI) of peninsular Florida. The GOES and NOAA-6 thermal IR, as well as National Climatic Center temperatures and rainfall, were also used. The HCMM apparent thermal inertia (ATI) images closely corresponded to the general soil map of Florida, based on soil drainage classes. Areas with low ATI overlay well-drained soils, such as deep sands and drained organic soils, whereas with high ATI overlay areas with wetlands and bodies of water. The HCMM ATI images also corresponded well with GOES-detected winter nocturnal cold-prone areas. Use of HCMM data with Carlson's energy balance model showed both high moisture availability (MA) and high thermal inertia (TI) of wetland-type surfaces and low MA and low TI of upland, well-drained soils. Since soil areas with low TI develop higher temperatures during the day, then antecedent patterns of highest maximum daytime surface temperature can also be used to predict nocturnal cold-prone areas in Florida.
Hydrological and hydraulic models for determination of flood-prone and flood inundation areas
NASA Astrophysics Data System (ADS)
Aksoy, Hafzullah; Sadan Ozgur Kirca, Veysel; Burgan, Halil Ibrahim; Kellecioglu, Dorukhan
Geographic Information Systems (GIS) are widely used in most studies on water resources. Especially, when the topography and geomorphology of study area are considered, GIS can ease the work load. Detailed data should be used in this kind of studies. Because of, either the complication of the models or the requirement of highly detailed data, model outputs can be obtained fast only with a good optimization. The aim in this study, firstly, is to determine flood-prone areas in a watershed by using a hydrological model considering two wetness indexes; the topographical wetness index, and the SAGA (System for Automated Geoscientific Analyses) wetness index. The wetness indexes were obtained in the Quantum GIS (QGIS) software by using the Digital Elevation Model of the study area. Flood-prone areas are determined by considering the wetness index maps of the watershed. As the second stage of this study, a hydraulic model, HEC-RAS, was executed to determine flood inundation areas under different return period-flood events. River network cross-sections required for this study were derived from highly detailed digital elevation models by QGIS. Also river hydraulic parameters were used in the hydraulic model. Modelling technology used in this study is made of freely available open source softwares. Based on case studies performed on watersheds in Turkey, it is concluded that results of such studies can be used for taking precaution measures against life and monetary losses due to floods in urban areas particularly.
Absence of food alternatives promotes risk-prone feeding of unpalatable substances in honey bees
Desmedt, Lucie; Hotier, Lucie; Giurfa, Martin; Velarde, Rodrigo; de Brito Sanchez, Maria Gabriela
The question of why animals sometimes ingest noxious substances is crucial to understand unknown determinants of feeding behaviour. Research on risk-prone feeding behaviour has largely focused on energy budgets as animals with low energy budgets tend to ingest more aversive substances. A less explored possibility is that risk-prone feeding arises from the absence of alternative feeding options, irrespectively of energy budgets. Here we contrasted these two hypotheses in late-fall and winter honey bees. We determined the toxicity of various feeding treatments and showed that when bees can choose between sucrose solution and a mixture of this sucrose solution and a noxious/unpalatable substance, they prefer the pure sucrose solution and reject the mixtures, irrespective of their energy budget. Yet, when bees were presented with a single feeding option and their escape possibilities were reduced, they consumed unexpectedly some of the previously rejected mixtures, independently of their energy budget. These findings are interpreted as a case of feeding helplessness, in which bees behave as if it were utterly helpless to avoid the potentially noxious food and consume it. They suggest that depriving bees of variable natural food sources may have the undesired consequence of increasing their acceptance of food that would be otherwise rejected. PMID:27534586
An Analysis of Muscle Activities of Healthy Women during Pilates Exercises in a Prone Position.
Kim, Bo-In; Jung, Ju-Hyeon; Shim, Jemyung; Kwon, Hae-Yeon; Kim, Haroo
[Purpose] This study analyzed the activities of the back and hip muscles during Pilates exercises conducted in a prone position. [Subjects] The subjects were 18 healthy women volunteers who had practiced at a Pilates center for more than three months. [Methods] The subjects performed three Pilates exercises. To examine muscle activity during the exercises, 8-channel surface electromyography (Noraxon USA, Inc., Scottsdale, AZ) was used. The surface electrodes were attached to the bilateral latissimus dorsi muscle, multifidus muscle, gluteus maximus, and semitendinous muscle. Three Pilates back exercises were compared: (1) double leg kick (DLK), (2) swimming (SW), and (3) leg beat (LB). Electrical muscle activation was normalized to maximal voluntary isometric contraction. Repeated measures analysis of variance was performed to assess the differences in activation levels among the exercises. [Results] The activity of the multifidus muscle was significantly high for the SW (52.3±11.0, 50.9±9.8) and LB exercises(51.8±12.8, 48.3±13.9) and the activity of the semitendinosus muscle was higher for the LB exercise (49.2±8.7, 52.9±9.3) than for the DLK and SW exercises. [Conclusion] These results may provide basic material for when Pilates exercises are performed in a prone position and may be useful information on clinical Pilates for rehabilitation programs.
Death receptor 6 contributes to autoimmunity in lupus-prone mice
Fujikura, Daisuke; Ikesue, Masahiro; Endo, Tsutomu; Chiba, Satoko; Higashi, Hideaki; Uede, Toshimitsu
Expansion of autoreactive follicular helper T (Tfh) cells is tightly restricted to prevent induction of autoantibody-dependent immunological diseases, such as systemic lupus erythematosus (SLE). Here we show expression of an orphan immune regulator, death receptor 6 (DR6/TNFRSF21), on a population of Tfh cells that are highly expanded in lupus-like disease progression in mice. Genome-wide screening reveals an interaction between syndecan-1 and DR6 resulting in immunosuppressive functions. Importantly, syndecan-1 is expressed specifically on autoreactive germinal centre (GC) B cells that are critical for maintenance of Tfh cells. Syndecan-1 expression level on GC B cells is associated with Tfh cell expansion and disease progression in lupus-prone mouse strains. In addition, Tfh cell suppression by DR6-specific monoclonal antibody delays disease progression in lupus-prone mice. These findings suggest that the DR6/syndecan-1 axis regulates aberrant GC reactions and could be a therapeutic target for autoimmune diseases such as SLE. PMID:28045014
Safe Sedation and Hypnosis using Dexmedetomidine for Minimally Invasive Spine Surgery in a Prone Position
Dexmedetomidine, an imidazoline compound, is a highly selective α2-adrenoceptor agonist with sympatholytic, sedative, amnestic, and analgesic properties. In order to minimize the patients' pain and anxiety during minimally invasive spine surgery (MISS) when compared to conventional surgery under general anesthesia, an adequate conscious sedation (CS) or monitored anesthetic care (MAC) should be provided. Commonly used intravenous sedatives and hypnotics, such as midazolam and propofol, are not suitable for operations in a prone position due to undesired respiratory depression. Dexmedetomidine converges on an endogenous non-rapid eye movement (NREM) sleep-promoting pathway to exert its sedative effects. The great merit of dexmedetomidine for CS or MAC is the ability of the operator to recognize nerve damage during percutaneous endoscopic lumbar discectomy, a representative MISS. However, there are 2 shortcomings for dexmedetomidine in MISS: hypotension/bradycardia and delayed emergence. Its hypotension/bradycardiac effects can be prevented by ketamine intraoperatively. Using atipamezole (an α2-adrenoceptor antagonist) might allow doctors to control the rate of recovery from procedural sedation in the future. MAC, with other analgesics such as ketorolac and opioids, creates ideal conditions for MISS. In conclusion, dexmedetomidine provides a favorable surgical condition in patients receiving MISS in a prone position due to its unique properties of conscious sedation followed by unconscious hypnosis with analgesia. However, no respiratory depression occurs based on the dexmedetomidine-related endogenous sleep pathways involves the inhibition of the locus coeruleus in the pons, which facilitates VLPO firing in the anterior hypothalamus. PMID:25317279
Thoracoscopic long myotomy in the prone position to treat rapid esophageal contractions with normal latency.
Nomura, Tsutomu; Iwakiri, Katsuhiko; Matsutani, Takeshi; Hagiwara, Nobutoshi; Fujita, Itsuro; Nakamura, Yoshiharu; Kawami, Noriyuki; Miyashita, Masao; Uchida, Eiji
A 56-year-old woman with an 8-year history of dysphagia and chest pain received a diagnosis of diffuse esophageal spasm by esophageal high-resolution manometry (HRM). Approximately 2 years of medical therapy was ineffective, and the patient's symptoms were worsening. Therefore, surgery was considered to be the most optimal treatment for this patient. The right thoracoscopic approach was selected because a long myotomy from the distal to proximal level of the esophagus was needed based on the HRM findings. The operation was performed in the prone position with establishment of pneumothorax. The total length of the myotomy was 16 cm, and the operation was finished within 2 hours. After the operation, the symptoms were considerably improved and no contractions were detected by HRM. The HRM findings before the operation were classified as rapid contractions with normal latency based on the 2012 Chicago classification of esophageal motility. Treatment for patients with rapid esophageal contractions with normal latency has not been previously described; however, treatment for diffuse esophageal spasm was considered to be pertinent to this patient. In conclusion, right thoracoscopic esophageal long myotomy in the prone position with establishment of pneumothorax may be useful when a proximal-level esophagomyotomy is required based on preoperative mapping by HRM.
Functioning of Neural Systems Supporting Emotion Regulation in Anxiety-Prone Individuals
Campbell-Sills, Laura; Simmons, Alan N.; Lovero, Kathryn L.; Rochlin, Alexis A.; Paulus, Martin P.; Stein, Murray B.
Previous neuroimaging studies suggest that prefrontal cortex (PFC) modulation of the amygdala and related limbic structures is an underlying neural substrate of effortful emotion regulation. Anxiety-prone individuals experience excessive negative emotions, signaling potential dysfunction of systems supporting down-regulation of negative emotions. We examined the hypothesis that anxious individuals require increased recruitment of lateral and medial PFC to decrease negative emotions. An emotion regulation task that involved viewing moderately negative images was presented during functional magnetic resonance imaging (fMRI). Participants with elevated trait anxiety scores (n = 13) and normal trait anxiety scores (n = 13) were trained to reduce negative emotions using cognitive reappraisal. Blood oxygenation level-dependent (BOLD) changes were contrasted for periods when participants were reducing emotions versus when they were maintaining emotions. Compared to healthy controls, anxious participants showed greater activation of brain regions implicated in effortful (lateral PFC) and automatic (subgenual anterior cingulate cortex) control of emotions during down-regulation of negative emotions. Left ventrolateral PFC activity was associated with greater self-reported reduction of distress in anxious participants, but not in healthy controls. These findings provide evidence of altered functioning of neural substrates of emotion regulation in anxiety-prone individuals. Anxious participants required greater engagement of lateral and medial PFC in order to successfully reduce negative emotions. PMID:20673804
Seismic hazard assessment and pattern recognition of earthquake prone areas in the Po Plain (Italy)
NASA Astrophysics Data System (ADS)
Gorshkov, Alexander; Peresan, Antonella; Soloviev, Alexander; Panza, Giuliano F.
A systematic and quantitative assessment, capable of providing first-order consistent information about the sites where large earthquakes may occur, is crucial for the knowledgeable seismic hazard evaluation. The methodology for the pattern recognition of areas prone to large earthquakes is based on the morphostructural zoning method (MSZ), which employs topographic data and present-day tectonic structures for the mapping of earthquake-controlling structures (i.e. the nodes formed around lineaments intersections) and does not require the knowledge about past seismicity. The nodes are assumed to be characterized by a uniform set of topographic, geologic, and geophysical parameters; on the basis of such parameters the pattern recognition algorithm defines a classification rule to discriminate seismogenic and non-seismogenic nodes. This methodology has been successfully applied since the early 1970s in a number of regions worldwide, including California, where it permitted the identification of areas that have been subsequently struck by strong events and that previously were not considered prone to strong earthquakes. Recent studies on the Iberian Peninsula and the Rhone Valley, have demonstrated the applicability of MSZ to flat basins, with a relatively flat topography. In this study, the analysis is applied to the Po Plain (Northern Italy), an area characterized by a flat topography, to allow for the systematic identification of the nodes prone to earthquakes with magnitude larger or equal to M=5.0. The MSZ method differs from the standard morphostructural analysis where the term "lineament" is used to define the complex of alignments detectable on topographic maps or on satellite images. According to that definition the lineament is locally defined and the existence of the lineament does not depend on the surrounding areas. In MSZ, the primary element is the block - a relatively homogeneous area - while the lineament is a secondary element of the morphostructure
of an error in satellite orientation and the sun being in a plane other than the equatorial plane may result in errors in position determination. The nature of the errors involved is described and their magnitudes estimated.
Orbit IMU alignment: Error analysis
NASA Technical Reports Server (NTRS)
Corson, R. W.
A comprehensive accuracy analysis of orbit inertial measurement unit (IMU) alignments using the shuttle star trackers was completed and the results are presented. Monte Carlo techniques were used in a computer simulation of the IMU alignment hardware and software systems to: (1) determine the expected Space Transportation System 1 Flight (STS-1) manual mode IMU alignment accuracy; (2) investigate the accuracy of alignments in later shuttle flights when the automatic mode of star acquisition may be used; and (3) verify that an analytical model previously used for estimating the alignment error is a valid model. The analysis results do not differ significantly from expectations. The standard deviation in the IMU alignment error for STS-1 alignments was determined to the 68 arc seconds per axis. This corresponds to a 99.7% probability that the magnitude of the total alignment error is less than 258 arc seconds.
Error analysis using organizational simulation.
Fridsma, D. B.
Organizational simulations have been used by project organizations in civil and aerospace industries to identify work processes and organizational structures that are likely to fail under certain conditions. Using a simulation system based on Galbraith's information-processing theory and Simon's notion of bounded-rationality, we retrospectively modeled a chemotherapy administration error that occurred in a hospital setting. Our simulation suggested that when there is a high rate of unexpected events, the oncology fellow was differentially backlogged with work when compared with other organizational members. Alternative scenarios suggested that providing more knowledge resources to the oncology fellow improved her performance more effectively than adding additional staff to the organization. Although it is not possible to know whether this might have prevented the error, organizational simulation may be an effective tool to prospectively evaluate organizational "weak links", and explore alternative scenarios to correct potential organizational problems before they generate errors. PMID:11079885
Sensation seeking and error processing.
Zheng, Ya; Sheng, Wenbin; Xu, Jing; Zhang, Yuanyuan
Sensation seeking is defined by a strong need for varied, novel, complex, and intense stimulation, and a willingness to take risks for such experience. Several theories propose that the insensitivity to negative consequences incurred by risks is one of the hallmarks of sensation-seeking behaviors. In this study, we investigated the time course of error processing in sensation seeking by recording event-related potentials (ERPs) while high and low sensation seekers performed an Eriksen flanker task. Whereas there were no group differences in ERPs to correct trials, sensation seeking was associated with a blunted error-related negativity (ERN), which was female-specific. Further, different subdimensions of sensation seeking were related to ERN amplitude differently. These findings indicate that the relationship between sensation seeking and error processing is sex-specific.
Error Field Correction in ITER
Park, Jong-kyu; Boozer, Allen H.; Menard, Jonathan E.; Schaffer, Michael J.
A new method for correcting magnetic field errors in the ITER tokamak is developed using the Ideal Perturbed Equilibrium Code (IPEC). The dominant external magnetic field for driving islands is shown to be localized to the outboard midplane for three ITER equilibria that represent the projected range of operational scenarios. The coupling matrices between the poloidal harmonics of the external magnetic perturbations and the resonant fields on the rational surfaces that drive islands are combined for different equilibria and used to determine an ordered list of the dominant errors in the external magnetic field. It is found that efficient and robust error field correction is possible with a fixed setting of the correction currents relative to the currents in the main coils across the range of ITER operating scenarios that was considered.
Constraint checking during error recovery
NASA Technical Reports Server (NTRS)
Lutz, Robyn R.; Wong, Johnny S. K.
The system-level software onboard a spacecraft is responsible for recovery from communication, power, thermal, and computer-health anomalies that may occur. The recovery must occur without disrupting any critical scientific or engineering activity that is executing at the time of the error. Thus, the error-recovery software may have to execute concurrently with the ongoing acquisition of scientific data or with spacecraft maneuvers. This work provides a technique by which the rules that constrain the concurrent execution of these processes can be modeled in a graph. An algorithm is described that uses this model to validate that the constraints hold for all concurrent executions of the error-recovery software with the software that controls the science and engineering activities of the spacecraft. The results are applicable to a variety of control systems with critical constraints on the timing and ordering of the events they control.
Real-time PCR in Food Science: PCR Diagnostics.
Rodriguez-Lazaro, David; Cook, Nigel; Hernandez, Marta
A principal consumer demand is a guarantee of the safety and quality of food. The presence of foodborne pathogens and their potential hazard, the use of genetically modified organisms (GMOs) in food production, and the correct labelling in foods suitable for vegetarians are among the subjects where society demands total transparency. The application of controls within the quality assessment programmes of the food industry is a way to satisfy these demands, and is necessary to ensure efficient analytical methodologies are possessed and correctly applied by the Food Sector. The use of real-time PCR has become a promising alternative approach in food diagnostics. It possesses a number of advantages over conventional culturing approaches, including rapidity, excellent analytical sensitivity and selectivity, and potential for quantification. However, the use of expensive equipment and reagents, the need for qualified personnel, and the lack of standardized protocols are impairing its practical implementation for food monitoring and control.
Comparison of next-generation droplet digital PCR (ddPCR) with quantitative PCR (qPCR) for enumeration of Cryptosporidium oocysts in faecal samples.
Yang, Rongchang; Paparini, Andrea; Monis, Paul; Ryan, Una
Clinical microbiology laboratories rely on quantitative PCR for its speed, sensitivity, specificity and ease-of-use. However, quantitative PCR quantitation requires the use of a standard curve or normalisation to reference genes. Droplet digital PCR provides absolute quantitation without the need for calibration curves. A comparison between droplet digital PCR and quantitative PCR-based analyses was conducted for the enteric parasite Cryptosporidium, which is an important cause of gastritis in both humans and animals. Two loci were analysed (18S rRNA and actin) using a range of Cryptosporidium DNA templates, including recombinant plasmids, purified haemocytometer-counted oocysts, commercial flow cytometry-counted oocysts and faecal DNA samples from sheep, cattle and humans. Each method was evaluated for linearity, precision, limit of detection and cost. Across the same range of detection, both methods showed a high degree of linearity and positive correlation for standards (R(2)⩾0.999) and faecal samples (R(2)⩾0.9750). The precision of droplet digital PCR, as measured by mean Relative Standard Deviation (RSD;%), was consistently better compared with quantitative PCR, particularly for the 18S rRNA locus, but was poorer as DNA concentration decreased. The quantitative detection of quantitative PCR was unaffected by DNA concentration, but droplet digital PCR quantitative PCR was less affected by the presence of inhibitors, compared with quantitative PCR. For most templates analysed including Cryptosporidium-positive faecal DNA, the template copy numbers, as determined by droplet digital PCR, were consistently lower than by quantitative PCR. However, the quantitations obtained by quantitative PCR are dependent on the accuracy of the standard curve and when the quantitative PCR data were corrected for pipetting and DNA losses (as determined by droplet digital PCR), then the sensitivity of both methods was comparable. A cost analysis based on 96 samples revealed that
Medication errors: definitions and classification.
Aronson, Jeffrey K
1. To understand medication errors and to identify preventive strategies, we need to classify them and define the terms that describe them. 2. The four main approaches to defining technical terms consider etymology, usage, previous definitions, and the Ramsey-Lewis method (based on an understanding of theory and practice). 3. A medication error is 'a failure in the treatment process that leads to, or has the potential to lead to, harm to the patient'. 4. Prescribing faults, a subset of medication errors, should be distinguished from prescription errors. A prescribing fault is 'a failure in the prescribing [decision-making] process that leads to, or has the potential to lead to, harm to the patient'. The converse of this, 'balanced prescribing' is 'the use of a medicine that is appropriate to the patient's condition and, within the limits created by the uncertainty that attends therapeutic decisions, in a dosage regimen that optimizes the balance of benefit to harm'. This excludes all forms of prescribing faults, such as irrational, inappropriate, and ineffective prescribing, underprescribing and overprescribing. 5. A prescription error is 'a failure in the prescription writing process that results in a wrong instruction about one or more of the normal features of a prescription'. The 'normal features' include the identity of the recipient, the identity of the drug, the formulation, dose, route, timing, frequency, and duration of administration. 6. Medication errors can be classified, invoking psychological theory, as knowledge-based mistakes, rule-based mistakes, action-based slips, and memory-based lapses. This classification informs preventive strategies.
Detection limits of quantitative and digital PCR assays and their influence in presence-absence surveys of environmental DNA
Hunter, Margaret; Dorazio, Robert M.; Butterfield, John S.; Meigs-Friend, Gaia; Nico, Leo; Ferrante, Jason
A set of universal guidelines is needed to determine the limit of detection (LOD) in PCR-based analyses of low concentration DNA. In particular, environmental DNA (eDNA) studies require sensitive and reliable methods to detect rare and cryptic species through shed genetic material in environmental samples. Current strategies for assessing detection limits of eDNA are either too stringent or subjective, possibly resulting in biased estimates of species' presence. Here, a conservative LOD analysis grounded in analytical chemistry is proposed to correct for overestimated DNA concentrations predominantly caused by the concentration plateau, a nonlinear relationship between expected and measured DNA concentrations. We have used statistical criteria to establish formal mathematical models for both quantitative and droplet digital PCR. To assess the method, a new Grass Carp (Ctenopharyngodon idella) TaqMan assay was developed and tested on both PCR platforms using eDNA in water samples. The LOD adjustment reduced Grass Carp occupancy and detection estimates while increasing uncertainty – indicating that caution needs to be applied to eDNA data without LOD correction. Compared to quantitative PCR, digital PCR had higher occurrence estimates due to increased sensitivity and dilution of inhibitors at low concentrations. Without accurate LOD correction, species occurrence and detection probabilities based on eDNA estimates are prone to a source of bias that cannot be reduced by an increase in sample size or PCR replicates. Other applications also could benefit from a standardized LOD such as GMO food analysis, and forensic and clinical diagnostics.
Development of a multiplex quantitative fluorescent PCR assay for identification of rearrangements in the AZFb and AZFc regions.
Zhang, Jun; Li, Pei-qiong; Yu, Qi-hong; Chen, Hua-yun; Li, Juan; He, Yun-shao
The azoospermia factor b (AZFb) and azoospermia factor c (AZFc) regions in the human Y chromosome consist of five palindromes constructed from six distinct families of amplicons and are prone to rearrangement. Partial deletion and duplication in the region can cause azoospermia or oligozoospermia and male infertility. The aim of the study was to establish a quantitative fluorescent PCR (QF-PCR) assay to classify AZFb and AZFc rearrangements. A single pair of fluorescent primers was designed to amplify simultaneously the amplicon in AZFc and the length-variant homologous sequences outside of the region as control. Since the copy number of the control sequences is fixed in the human genome, dosage of the target could be easily obtained through comparing the height of the fluorescent peaks between the target and the control after amplification with limited PCR cycles. Most types of rearrangements in AZFb and AZFc regions could be classified with QF-PCR containing four such primer pairs. Eleven types of rearrangement in AZFb and AZFc regions were well discriminated with QF-PCR. In conclusion, QF-PCR is a simple and reliable method to detect rearrangements in AZFb and AZFc.
Detection limits of quantitative and digital PCR assays and their influence in presence-absence surveys of environmental DNA.
Hunter, Margaret E; Dorazio, Robert M; Butterfield, John S S; Meigs-Friend, Gaia; Nico, Leo G; Ferrante, Jason A
A set of universal guidelines is needed to determine the limit of detection (LOD) in PCR-based analyses of low-concentration DNA. In particular, environmental DNA (eDNA) studies require sensitive and reliable methods to detect rare and cryptic species through shed genetic material in environmental samples. Current strategies for assessing detection limits of eDNA are either too stringent or subjective, possibly resulting in biased estimates of species' presence. Here, a conservative LOD analysis grounded in analytical chemistry is proposed to correct for overestimated DNA concentrations predominantly caused by the concentration plateau, a nonlinear relationship between expected and measured DNA concentrations. We have used statistical criteria to establish formal mathematical models for both quantitative and droplet digital PCR. To assess the method, a new Grass Carp (Ctenopharyngodon idella) TaqMan assay was developed and tested on both PCR platforms using eDNA in water samples. The LOD adjustment reduced Grass Carp occupancy and detection estimates while increasing uncertainty-indicating that caution needs to be applied to eDNA data without LOD correction. Compared to quantitative PCR, digital PCR had higher occurrence estimates due to increased sensitivity and dilution of inhibitors at low concentrations. Without accurate LOD correction, species occurrence and detection probabilities based on eDNA estimates are prone to a source of bias that cannot be reduced by an increase in sample size or PCR replicates. Other applications also could benefit from a standardized LOD such as GMO food analysis and forensic and clinical diagnostics.
Automatic-repeat-request error control schemes
NASA Technical Reports Server (NTRS)
Lin, S.; Costello, D. J., Jr.; Miller, M. J.
Error detection incorporated with automatic-repeat-request (ARQ) is widely used for error control in data communication systems. This method of error control is simple and provides high system reliability. If a properly chosen code is used for error detection, virtually error-free data transmission can be attained. Various types of ARQ and hybrid ARQ schemes, and error detection using linear block codes are surveyed.
Real-Time PCR (qPCR) Primer Design Using Free Online Software
ERIC Educational Resources Information Center
Thornton, Brenda; Basu, Chhandak
Real-time PCR (quantitative PCR or qPCR) has become the preferred method for validating results obtained from assays which measure gene expression profiles. The process uses reverse transcription polymerase chain reaction (RT-PCR), coupled with fluorescent chemistry, to measure variations in transcriptome levels between samples. The four most…
Digital stereo photogrammetry for grain-scale monitoring of fluvial surfaces: Error evaluation and workflow optimisation
NASA Astrophysics Data System (ADS)
Bertin, Stephane; Friedrich, Heide; Delmas, Patrice; Chan, Edwin; Gimel'farb, Georgy
Grain-scale monitoring of fluvial morphology is important for the evaluation of river system dynamics. Significant progress in remote sensing and computer performance allows rapid high-resolution data acquisition, however, applications in fluvial environments remain challenging. Even in a controlled environment, such as a laboratory, the extensive acquisition workflow is prone to the propagation of errors in digital elevation models (DEMs). This is valid for both of the common surface recording techniques: digital stereo photogrammetry and terrestrial laser scanning (TLS). The optimisation of the acquisition process, an effective way to reduce the occurrence of errors, is generally limited by the use of commercial software. Therefore, the removal of evident blunders during post processing is regarded as standard practice, although this may introduce new errors. This paper presents a detailed evaluation of a digital stereo-photogrammetric workflow developed for fluvial hydraulic applications. The introduced workflow is user-friendly and can be adapted to various close-range measurements: imagery is acquired with two Nikon D5100 cameras and processed using non-proprietary "on-the-job" calibration and dense scanline-based stereo matching algorithms. Novel ground truth evaluation studies were designed to identify the DEM errors, which resulted from a combination of calibration errors, inaccurate image rectifications and stereo-matching errors. To ensure optimum DEM quality, we show that systematic DEM errors must be minimised by ensuring a good distribution of control points throughout the image format during calibration. DEM quality is then largely dependent on the imagery utilised. We evaluated the open access multi-scale Retinex algorithm to facilitate the stereo matching, and quantified its influence on DEM quality. Occlusions, inherent to any roughness element, are still a major limiting factor to DEM accuracy. We show that a careful selection of the camera
Prone Positioning Causes the Heart To Be Displaced Anteriorly Within the Thorax: Implications for Breast Cancer Treatment
Chino, Junzo P. Marks, Lawrence B.
Introduction: Prone positioning has been suggested as an alternative to the conventional supine position for patients receiving breast radiotherapy, but few data exist on how this may alter heart location. We herein quantitatively compare the intrathoracic location of the heart in the prone and supine positions in patients treated for breast cancer. Methods and Materials: In 16 patients treated with tangent photons for breast cancer, the computed tomography planning images (obtained in the supine position) and diagnostic magnetic resonance images (obtained in the prone position) were studied. For each case, the distance between the anterior pericardium and the anterior chest wall was measured at nine specific points; three points at each of three axial levels. The differences in the measurements between the prone and supine positions were compared with the Wilcoxon signed-rank test. Results: There is a systematic displacement of the lateral and superior aspect of the heart closer to the chest wall in the prone vs. supine position (mean displacement 19 mm (95% confidence interval 13.7-25.1 mm, p < 0.001); the medial and inferior aspects remain fixed. There was also a reduction in volume of lung interposed between the heart and chest wall when prone (mean decrease of 22 mL, p < 0.001 for difference). Conclusions: The superior and lateral aspects of the heart typically move anteriorly during prone positioning compared with the supine position. This may have negative consequences in situations in which the high-risk target tissues include the chest wall or deep breast.
Lossi, Laura; Gambino, Graziana; Salio, Chiara; Merighi, Adalberto
In situ polymerase chain reaction (PCR) is a histological technique that exploits the advantages of PCR for detection of mRNA directly in tissue sections. It somehow conjugates together PCR and in situ hybridization that is more traditionally employed for mRNA localization in cell organelles, intact cells, or tissue sections. This chapter describes the application of in situ PCR for neuropeptide mRNA localization. We provide here a detailed protocol for direct in situ reverse transcription (RT) PCR (RT-PCR) with nonradioactive probes after fixation and paraffin embedding or cryosectioning. Digoxigenin-labeled nucleotides (digoxigenin-11-dUTP) are incorporated in the PCR product after RT and subsequently detected with an anti-digoxigenin antibody conjugated with alkaline phosphatase. The procedure can be modified for use with fluorescent probes and employed in combination with enzyme/fluorescence immunocytochemical labeling.
Management of human error by design
NASA Technical Reports Server (NTRS)
Wiener, Earl
Design-induced errors and error prevention as well as the concept of lines of defense against human error are discussed. The concept of human error prevention, whose main focus has been on hardware, is extended to other features of the human-machine interface vulnerable to design-induced errors. In particular, it is pointed out that human factors and human error prevention should be part of the process of transport certification. Also, the concept of error tolerant systems is considered as a last line of defense against error.
Variability in DNA polymerase efficiency: effects of random error, DNA extraction method, and isolate type
Technology Transfer Automated Retrieval System (TEKTRAN)
Using computer-generated data calculated with known amounts of random error (E = 1, 5 & 10%) associated with calculated qPCR cycle number (C ) at four jth 1:10 dilutions, we found that the "efficiency" (eff) associated with each population distribution of n = 10,000 measurements varied from 0.95 to ...
Delineation of flood-prone areas and the identification of residential hotspots for two African cities
NASA Astrophysics Data System (ADS)
De Risi, Raffaele; Jalayer, Fatemeh; De Paola, Francesco; Iervolino, Iunio; Giugni, Maurizio; Topa, Maria Elena; Yonas, Nebyou; Nebebe, Alemu; Woldegerima, Tekle; Yeshitela, Kumelachew; Kibassa, Deusdedit; Shemdoe, Riziki; Cavan, Gina; Lindley, Sarah; Renner, Florian; Printz, Andreas
This work employs two GIS-based frameworks for identifying the urban residential hot spots. This is done by overlaying a map of potentially flood prone areas (the topographic wetness index, TWI) and a map of urban morphology types (UMT) classified as residential. The topographic wetness index (TWI, Qin et al. 2011) allows for the delineation of a portion of a hydrographic basin potentially exposed to flood inundation by identifying all the areas characterized by a topographic index that exceeds a given threshold. The urban morphological types (Pauleit and Duhme 2000, Gill et al. 2008, Cavan et al. 2012) form the foundation of a classification scheme which brings together facets of urban form and function. The application of the UMTs allows the delineation of geographical units. The distinction of UMTs at a 'meso'-scale (i.e. between the city level and that of the individual units) makes a suitable basis for the spatial analysis of cities. The TWI threshold value depends on the resolution of the digital elevation model (DEM), topology of the hydrographic basin (i.e. urban, peri-urban or rural) and the constructed infrastructure (Manfreda et al. 2011). This threshold value is usually calibrated based on the results of detailed delineation of the inundation profile for selected zones. In this study, the TWI threshold is calibrated based on the calculated inundation profiles for various return periods for selected zones within the basin through a Bayesian framework. The Bayesian framework enables the probabilistic characterization of the threshold value by calculating the complementary probability of false delineation of flood prone zones as a function of various threshold values. For a given return period, the probability of false delineation is calculated as the sum of the probability of indicating a zone flood prone which is not indicated as such by the inundation profile and the probability that a zone is indicated as not flood prone but indicated as flood prone by
Multiplexed Primer Prediction for PCR
MPP predicts sets of multiplex-compatible primers for Polymerase Chain Reaction (PCR), finding a near minimal set of primers such that at least one amplicon will be generated from every target sequence in the input file. The code finds highly conserved oligos that are suitable as primers, according to user-specified desired primer characteristics such as length, melting temperature, and amplicon length. The primers are predicted not to form unwanted dimer or hairpin structures. The target sequences used as input can be diverse, since no multiple sequence alighment is required. The code is scalable, taking up to tens of thousands of sequences as input, and works, for example, to find a "universal primer set" for all viral genomes provided as a single input file. The code generates a periodic check-point file, thus in the event of premature execution termination, the application can be restarted from the last check-point file.
Design risk assessment for burst-prone mines: Application in a Canadian mine
NASA Astrophysics Data System (ADS)
Cheung, David J.
A proactive stance towards improving the effectiveness and consistency of risk assessments has been adopted recently by mining companies and industry. The next 10-20 years forecasts that ore deposits accessible using shallow mining techniques will diminish. The industry continues to strive for success in "deeper" mining projects in order to keep up with the continuing demand for raw materials. Although the returns are quite profitable, many projects have been sidelined due to high uncertainty and technical risk in the mining of the mineral deposit. Several hardrock mines have faced rockbursting and seismicity problems. Within those reported, mines in countries like South Africa, Australia and Canada have documented cases of severe rockburst conditions attributed to the mining depth. Severe rockburst conditions known as "burst-prone" can be effectively managed with design. Adopting a more robust design can ameliorate the exposure of workers and equipment to adverse conditions and minimize the economic consequences, which can hinder the bottom line of an operation. This thesis presents a methodology created for assessing the design risk in burst-prone mines. The methodology includes an evaluation of relative risk ratings for scenarios with options of risk reduction through several design principles. With rockbursts being a hazard of seismic events, the methodology is based on research in the area of mining seismicity factoring in rockmass failure mechanisms, which results from a combination of mining induced stress, geological structures, rockmass properties and mining influences. The methodology was applied to case studies at Craig Mine of Xstrata Nickel in Sudbury, Ontario, which is known to contain seismically active fault zones. A customized risk assessment was created and applied to rockburst case studies, evaluating the seismic vulnerability and consequence for each case. Application of the methodology to Craig Mine demonstrates that changes in the design can
Formenti, Silvia C.; Hsu, Howard; Fenton-Kerimian, Maria; Roses, Daniel; Guth, Amber; Jozsef, Gabor; Goldberg, Judith D.; DeWyngaert, J. Keith
Purpose To report the 5-year results of a prospective trial of three-dimensional conformal external beam radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation in the prone position (P-APBI). Methods Post-menopausal patients with Stage I breast cancer with non palpable <2 cm tumors, negative margins, and negative nodes, positive hormonal receptors, and no extensive intraductal component (EIC) were eligible. The trial was offered only once eligible patients had refused to undergo standard whole-breast radiotherapy. Patients were simulated and treated on a dedicated table for prone set-up. The 3D-CRT delivered was 30 Gy in five 6 Gy/daily fractions over 10 days with port film verification at each treatment. Ipsilateral breast, ipsilateral nodal, contralateral breast, and distant failure (IBF, INF, CBF, DF) were estimated using the cumulative incidence method. Disease-free, overall, and cancer-specific survival (DFS, OS, CSS) were recorded. Results One hundred patients accrued to this IRB- approved prospective trial, one with bilateral breast cancer. One patient withdrew consent after simulation and another elected to interrupt radiotherapy after receiving two treatments. Ninety-eight patients are evaluable for toxicity and, in one case, both breasts were treated with PBI. Median patient age was 68 years (range 53–88 years); in 55% the tumor size was <1 cm. All patients had hormonal receptor positive cancers: 87% underwent adjuvant anti-hormonal therapy. At a median follow-up of 64 months (range, 2–125 months), there was one local recurrence (1% IBF) and one contralateral breast cancer (1% CBF). There were no deaths due to breast cancer by 5 years. Grade 3 late toxicities occurred in 2 patients (1 breast edema, 1 transient breast pain). Cosmesis was rated good/excellent in 89% of patients with at least 36 months follow-up. Conclusions Five-year efficacy and toxicity of 3D-CRT to deliver prone-PBI are comparable to other experiences with similar
Multichannel error correction code decoder
NASA Technical Reports Server (NTRS)
Wagner, Paul K.; Ivancic, William D.
A brief overview of a processing satellite for a mesh very-small-aperture (VSAT) communications network is provided. The multichannel error correction code (ECC) decoder system, the uplink signal generation and link simulation equipment, and the time-shared decoder are described. The testing is discussed. Applications of the time-shared decoder are recommended.
NASA Astrophysics Data System (ADS)
Eremina, Svetlana V.; Korneva, Anna A.
The paper presents analysis of the errors made by ESP (English for specific purposes) users which have been considered as typical. They occur as a result of misuse of resources of English grammar and tend to resist. Their origin and places of occurrence have also been discussed.
Error Analysis and Remedial Teaching.
ERIC Educational Resources Information Center
Corder, S. Pit
The purpose of this paper is to analyze the role of error analysis in specifying and planning remedial treatment in second language learning. Part 1 discusses situations that demand remedial action. This is a quantitative assessment that requires measurement of the varying degrees of disparity between the learner's knowledge and the demands of the…
Sampling Errors of Variance Components.
ERIC Educational Resources Information Center
Sanders, Piet F.
A study on sampling errors of variance components was conducted within the framework of generalizability theory by P. L. Smith (1978). The study used an intuitive approach for solving the problem of how to allocate the number of conditions to different facets in order to produce the most stable estimate of the universe score variance. Optimization…
NASA Astrophysics Data System (ADS)
Swartz, Clifford E.
In Victorian literature it was usually some poor female who came to see the error of her ways. How prescient of her! How I wish that all writers of manuscripts for The Physics Teacher would come to similar recognition of this centerpiece of measurement. For, Brothers and Sisters, we all err.
Amplify Errors to Minimize Them
ERIC Educational Resources Information Center
Stewart, Maria Shine
In this article, the author offers her experience of modeling mistakes and writing spontaneously in the computer classroom to get students' attention and elicit their editorial response. She describes how she taught her class about major sentence errors--comma splices, run-ons, and fragments--through her Sentence Meditation exercise, a rendition…
Having Fun with Error Analysis
ERIC Educational Resources Information Center
Siegel, Peter
We present a fun activity that can be used to introduce students to error analysis: the M&M game. Students are told to estimate the number of individual candies plus uncertainty in a bag of M&M's. The winner is the group whose estimate brackets the actual number with the smallest uncertainty. The exercise produces enthusiastic discussions and…
NASA Technical Reports Server (NTRS)
Rice, R. F.
The root-mean-square error performance measure is used to compare the relative performance of several widely known source coding algorithms with the RM2 image data compression system. The results demonstrate that RM2 has a uniformly significant performance advantage.
The Zero Product Principle Error.
ERIC Educational Resources Information Center
Padula, Janice
Argues that the challenge for teachers of algebra in Australia is to find ways of making the structural aspects of algebra accessible to a greater percentage of students. Uses the zero product principle to provide an example of a common student error grounded in the difficulty of understanding the structure of algebra. (DDR)
Competing Criteria for Error Gravity.
ERIC Educational Resources Information Center
Hughes, Arthur; Lascaratou, Chryssoula
Presents study in which native-speaker teachers of English, Greek teachers of English, and English native-speakers who were not teachers judged seriousness of errors made by Greek-speaking students of English in their last year of high school. Results show native English speakers were more lenient than Greek teachers, and three groups differed in…
ERIC Educational Resources Information Center
Labov, William; Baker, Bettina
Early efforts to apply knowledge of dialect differences to reading stressed the importance of the distinction between differences in pronunciation and mistakes in reading. This study develops a method of estimating the probability that a given oral reading that deviates from the text is a true reading error by observing the semantic impact of the…
Error Processing in Huntington's Disease
Andrich, Jürgen; Gold, Ralf; Falkenstein, Michael
Background Huntington's disease (HD) is a genetic disorder expressed by a degeneration of the basal ganglia inter alia accompanied with dopaminergic alterations. These dopaminergic alterations are related to genetic factors i.e., CAG-repeat expansion. The error (related) negativity (Ne/ERN), a cognitive event-related potential related to performance monitoring, is generated in the anterior cingulate cortex (ACC) and supposed to depend on the dopaminergic system. The Ne is reduced in Parkinson's Disease (PD). Due to a dopaminergic deficit in HD, a reduction of the Ne is also likely. Furthermore it is assumed that movement dysfunction emerges as a consequence of dysfunctional error-feedback processing. Since dopaminergic alterations are related to the CAG-repeat, a Ne reduction may furthermore also be related to the genetic disease load. Methodology/Principle Findings We assessed the error negativity (Ne) in a speeded reaction task under consideration of the underlying genetic abnormalities. HD patients showed a specific reduction in the Ne, which suggests impaired error processing in these patients. Furthermore, the Ne was closely related to CAG-repeat expansion. Conclusions/Significance The reduction of the Ne is likely to be an effect of the dopaminergic pathology. The result resembles findings in Parkinson's Disease. As such the Ne might be a measure for the integrity of striatal dopaminergic output function. The relation to the CAG-repeat expansion indicates that the Ne could serve as a gene-associated "cognitive" biomarker in HD. PMID:17183717
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at firstname.lastname@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at firstname.lastname@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication error report analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at firstname.lastname@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at email@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
ISMP Medication Error Report Analysis.
These medication errors have occurred in health care facilities at least once. They will happen again-perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below. Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at firstname.lastname@example.com. ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
Reduced discretization error in HZETRN
Slaba, Tony C.; Blattnig, Steve R.; Tweed, John
The deterministic particle transport code HZETRN is an efficient analysis tool for studying the effects of space radiation on humans, electronics, and shielding materials. In a previous work, numerical methods in the code were reviewed, and new methods were developed that further improved efficiency and reduced overall discretization error. It was also shown that the remaining discretization error could be attributed to low energy light ions (A < 4) with residual ranges smaller than the physical step-size taken by the code. Accurately resolving the spectrum of low energy light particles is important in assessing risk associated with astronaut radiation exposure. In this work, modifications to the light particle transport formalism are presented that accurately resolve the spectrum of low energy light ion target fragments. The modified formalism is shown to significantly reduce overall discretization error and allows a physical approximation to be removed. For typical step-sizes and energy grids used in HZETRN, discretization errors for the revised light particle transport algorithms are shown to be less than 4% for aluminum and water shielding thicknesses as large as 100 g/cm{sup 2} exposed to both solar particle event and galactic cosmic ray environments.
ERIC Educational Resources Information Center
Kane, Michael
Errors don't exist in our data, but they serve a vital function. Reality is complicated, but our models need to be simple in order to be manageable. We assume that attributes are invariant over some conditions of observation, and once we do that we need some way of accounting for the variability in observed scores over these conditions of…
ERIC Educational Resources Information Center
Theory of Test Translation Error
ERIC Educational Resources Information Center
Solano-Flores, Guillermo; Backhoff, Eduardo; Contreras-Nino, Luis Angel
In this article, we present a theory of test translation whose intent is to provide the conceptual foundation for effective, systematic work in the process of test translation and test translation review. According to the theory, translation error is multidimensional; it is not simply the consequence of defective translation but an inevitable fact…
Toward a cognitive taxonomy of medical errors.
Zhang, Jiajie; Patel, Vimla L; Johnson, Todd R; Shortliffe, Edward H
One critical step in addressing and resolving the problems associated with human errors is the development of a cognitive taxonomy of such errors. In the case of errors, such a taxonomy may be developed (1) to categorize all types of errors along cognitive dimensions, (2) to associate each type of error with a specific underlying cognitive mechanism, (3) to explain why, and even predict when and where, a specific error will occur, and (4) to generate intervention strategies for each type of error. Based on Reason's (1992) definition of human errors and Norman's (1986) cognitive theory of human action, we have developed a preliminary action-based cognitive taxonomy of errors that largely satisfies these four criteria in the domain of medicine. We discuss initial steps for applying this taxonomy to develop an online medical error reporting system that not only categorizes errors but also identifies problems and generates solutions.
Error and its meaning in forensic science.
Christensen, Angi M; Crowder, Christian M; Ousley, Stephen D; Houck, Max M
The discussion of "error" has gained momentum in forensic science in the wake of the Daubert guidelines and has intensified with the National Academy of Sciences' Report. Error has many different meanings, and too often, forensic practitioners themselves as well as the courts misunderstand scientific error and statistical error rates, often confusing them with practitioner error (or mistakes). Here, we present an overview of these concepts as they pertain to forensic science applications, discussing the difference between practitioner error (including mistakes), instrument error, statistical error, and method error. We urge forensic practitioners to ensure that potential sources of error and method limitations are understood and clearly communicated and advocate that the legal community be informed regarding the differences between interobserver errors, uncertainty, variation, and mistakes.
Does a Species' Extinction–Proneness Predict Its Contribution to Nestedness? A Test Using a Sunbird-Tree Visitation Network
Nsor, Charles A.; Godsoe, William
Animal pollinators and the plants they pollinate depend on networks of mutualistic partnerships and more broadly on the stability of such networks. Based mainly on insect-plant visitation networks, theory predicts that species that are most prone to extinction contribute the most to nestedness, however empirical tests are rare. We used a sunbird-tree visitation network within which were both extinction prone vs non extinction prone sunbird species to test the idea. We predicted that the extinction prone species would contribute the most to nestedness. Using local abundance as a proxy for extinction risk we considered that locally rare sunbird species, by virtue of their small population size and associated demographic stochasticity to be more at risk of extinction than the common species. Our network was not strongly nested and all sunbird species made similar contributions to nestedness, so that in our empirical test, extinction proneness did not predict contribution to nestedness. The consequences of this finding remain unclear. It may be that network theory based on plant-insect mutualisms is not widely applicable and does not work for tree- sunbird mutualistic networks. Alternatively it may be that our network was too small to provide results with any statistical power. Without doubt our study highlights the problems faced when testing network theory in the field; a plethora of ecological considerations can variously impact on results. PMID:28103287
Does a Species' Extinction-Proneness Predict Its Contribution to Nestedness? A Test Using a Sunbird-Tree Visitation Network.
Nsor, Charles A; Chapman, Hazel M; Godsoe, William
Animal pollinators and the plants they pollinate depend on networks of mutualistic partnerships and more broadly on the stability of such networks. Based mainly on insect-plant visitation networks, theory predicts that species that are most prone to extinction contribute the most to nestedness, however empirical tests are rare. We used a sunbird-tree visitation network within which were both extinction prone vs non extinction prone sunbird species to test the idea. We predicted that the extinction prone species would contribute the most to nestedness. Using local abundance as a proxy for extinction risk we considered that locally rare sunbird species, by virtue of their small population size and associated demographic stochasticity to be more at risk of extinction than the common species. Our network was not strongly nested and all sunbird species made similar contributions to nestedness, so that in our empirical test, extinction proneness did not predict contribution to nestedness. The consequences of this finding remain unclear. It may be that network theory based on plant-insect mutualisms is not widely applicable and does not work for tree- sunbird mutualistic networks. Alternatively it may be that our network was too small to provide results with any statistical power. Without doubt our study highlights the problems faced when testing network theory in the field; a plethora of ecological considerations can variously impact on results.
How Informative are the Vertical Buoyancy and the Prone Gliding Tests to Assess Young Swimmers' Hydrostatic and Hydrodynamic Profiles?
Barbosa, Tiago M; Costa, Mário J; Morais, Jorge E; Moreira, Marc; Silva, António J; Marinho, Daniel A
The aim of this research was to develop a path-flow analysis model to highlight the relationships between buoyancy and prone gliding tests and some selected anthropometrical and biomechanical variables. Thirty-eight young male swimmers (12.97 ± 1.05 years old) with several competitive levels were evaluated. It were assessed the body mass, height, fat mass, body surface area, vertical buoyancy, prone gliding after wall push-off, stroke length, stroke frequency and velocity after a maximal 25 [m] swim. The confirmatory model included the body mass, height, fat mass, prone gliding test, stroke length, stroke frequency and velocity. All theoretical paths were verified except for the vertical buoyancy test that did not present any relationship with anthropometrical and biomechanical variables nor with the prone gliding test. The good-of-fit from the confirmatory path-flow model, assessed with the standardized root mean square residuals (SRMR), is considered as being close to the cut-off value, but even so not suitable of the theory (SRMR = 0.11). As a conclusion, vertical buoyancy and prone gliding tests are not the best techniques to assess the swimmer's hydrostatic and hydrodynamic profile, respectively.
Differences in Irradiated Lung Gene Transcription Between Fibrosis-Prone C57BL/6NHsd and Fibrosis-Resistant C3H/HeNHsd Mice
Kalash, Ronny; Berhane, Hebist; Au, Jeremiah; Rhieu, Byung Han; Epperly, Michael W.; Goff, Julie; Dixon, Tracy; Wang, Hong; Zhang, Xichen; Franicola, Darcy; Shinde, Ashwin; Greenberger, Joel S.
Background/Aim We compared pulmonary irradiation-induced whole lung, gene transcripts, over 200 days after 20 Gy thoracic irradiation in fibrosis-prone C57BL/6NHsd with fibrosis-resistant C3H/HeNHsd female mice. Materials and Methods Lung specimens were analyzed by rt-PCR and changes over time in representative gene transcript levels were correlated with protein levels using Western Blot. Results C3H/HeNHsd mice showed a significantly longer duration of elevation of gene transcripts for stress-response genes (NFkβ, Nrf2, Sp1, Ap1), radioprotection gene (SOD2), and endothelial cell associated genes (vWF, VEGFa). C57BL/6NHsd mice showed acute elevation then downregulation and a second elevation in gene transcripts for NFkβ, CTGF, IGFbp7, TNFα, collagen1a, and TLR4. There were reciprocal patterns of elevation and decrease in levels of transcripts for epigenetic reader proteins Brd1, 2, 3, and 4 between mouse strains. Conclusions Regulatory pathways linked to radiation pulmonary fibrosis may identify new targets for anti-fibrotic radiation mitigators. PMID:24632969
Comparison of constitutive gene expression levels of hepatic cholesterol biosynthetic enzymes between Wistar-Kyoto and stroke-prone spontaneously hypertensive rats.
Nemoto, Kiyomitsu; Ikeda, Ayaka; Ito, Sei; Miyata, Misaki; Yoshida, Chiaki; Degawa, Masakuni
Serum total cholesterol amounts in the stroke-prone hypertensive rat (SHRSP) strain are lower than in the normotensive control strain, Wistar-Kyoto (WKY) rat. To understand the strain difference, constitutive gene expression levels of hepatic cholesterol biosynthetic enzymes in male 8-week-old SHRSP and WKY rats were comparatively examined by DNA microarray and real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses. Of 22 cholesterol biosynthetic enzyme genes, expression levels of 8 genes, Pmvk, Idi1, Fdps, Fdft1, Sqle, Lss, Sc4mol, and Hsd17b7, in SHRSP were less than 50% those of the WKY rats; especially, the expression level of Sqle gene, encoding squalene epoxidase, a rate-limiting enzyme in cholesterol biosynthesis pathway, was about 20%. The gene expression level of sterol regulatory element-binding protein-2 (SREBP-2), which functions as a transcription factor upregulating gene expression of cholesterol biosynthetic enzymes, in SHRSP was about 70% of that in WKY rats. These results demonstrate the possibility that the lower serum total cholesterol level in SHRSP is defined by lower gene expression of most hepatic cholesterol biosynthetic enzymes. In particular, decreased gene expression level of Sqle gene might be the most essential factor. Moreover, the broad range of lowered rates of these genes in SHRSP suggests that the abnormal function and/or expression not only of SREBP-2 but also of one or more other transcription factors for those gene expressions exist in SHRSP.
Neural correlates of post-error slowing during a stop signal task: a functional magnetic resonance imaging study.
Li, Chiang-shan Ray; Huang, Cong; Yan, Peisi; Paliwal, Prashni; Constable, Robert Todd; Sinha, Rajita
The ability to detect errors and adjust behavior accordingly is essential for maneuvering in an uncertain environment. Errors are particularly prone to occur when multiple, conflicting responses are registered in a situation that requires flexible behavioral outputs; for instance, when a go signal requires a response and a stop signal requires inhibition of the response during a stop signal task (SST). Previous studies employing the SST have provided ample evidence indicating the importance of the medial cortical brain regions in conflict/error processing. Other studies have also related these regional activations to postconflict/error behavioral adjustment. However, very few studies have directly explored the neural correlates of postconflict/error behavioral adjustment. Here we employed an SST to elicit errors in approximately half of the stop trials despite constant behavioral adjustment of the observers. Using functional magnetic resonance imaging, we showed that prefrontal loci including the ventrolateral prefrontal cortex are involved in post-error slowing in reaction time. These results delineate the neural circuitry specifically involved in error-associated behavioral modifications.