texts: Why is male balding so common in comparison to female balding?

texts: I have heard that over 30% of men will be bald by 30, and that 60% will be bald by 50. However, I hardly ever see a bald woman unless it is a story about a cancer survivor or someone going through cancer, meaning that they lost their hair through chemotherapy rather than natural balding. I do not understand why this is. I do know that women tend to have longer hair than men, so maybe their follicles are more active, preventing them from going bald. If someone could correct my explanation, that'd be appreciated.


texts: Is amphibians being descended from fish reflected in the animalia taxonomy?

texts:
I think it is common knowledge that amphibians are descended from fish. At some point there was a transition from sea to land.
But when I try to confirm this through the Animalia taxonomy, the scientific classification of fish goes

https://en.wikipedia.org/wiki/Fish
while the scientific classification of amphibians go

https://en.wikipedia.org/wiki/Amphibian
If we draw this as a tree of sorts, we end up with

it seems to be quite obvious that fish and amphibians belong to the same phylum but different clades, but I'm not sure how that proves that amphibians are directly descended from fish?
I'm interested in a tree that shows amphibians branching off of the fish lineage.


texts: Why we do not get hurt from HCl secreted in the stomach?

texts: I read in my book that during digestion our stomach secretes hydrochloric acid ($HCl$). Why we do not get hurt from it? It was also said that mucous provides protection, but from where is it coming?


texts:
How do we know that everybody's DNA fingerprint is unique?

I know, I know, everybody's DNA is unique.

But when we do DNA fingerprinting, we're looking at very specific regions of high variability.

How do we know that just by chance, two people's DNA could be the exact same in the spot(s) we're observing.

With real fingerprints, uniqueness is (almost) guaranteed (I believe it's a 1 in 64 billion chance) because they are developed by physical stresses on the fetus in the womb.

Is there any similar mechanism/affect that acts on these non-coding/highly variable sections of DNA?

Thanks!

evamvid


texts: What type of force holds my body rigid & doesn't make it collapse?

texts: My query is that as atoms & its molecules have inter & intra molecular forces,like that only what type of force keeps the cells bonded to each other & prevent it from collapsing ever since.


texts: Why should plants transform glucose into sucrose before transporting it to other parts?

texts: I've learned that plants transform glucose into sucrose before sending it into phloem. But the process seems to be complex and energy comsuming. Why should plants do it? Is it really necessary?


texts: How to study the number of herbivores per type of tree and time of day?

texts:
Suppose I want to find out the number of herbivores in different kinds of trees, and also compare the numbers between day and night. How would this kind of study be run in practice? It easy to think of several possible confounding factors, such as the health of the trees, weather, etc.

If the trees are big, it is also difficult to find every living thing from that. One could of course then count the number of herbivores per defined area but again, picking the area should be carefully controlled.

From a statistical perspective, I can just make an estimate of expected effect size, and calculate the sample size that is about enough for detecting possible differences in the above mentioned conditions. However, I find these other aspects very difficult to do... All help would be appreciated :)


texts: Can an argument be made that humans are 90% bacterial?

texts:
On the blog, All about Scientist in Microword: Microbiology, I read the post We are 90% bacteria, actually, which says that humans are 90% bacterial cells.

If this is the case, then why don't we behave like them and why isn't the bacteria genetic material more dominant?

As bacteria helps us in making many enzymes for us, can we say that we are symbiotic creatures?


texts: Proportion of amino acids from a random polymer of U and C

texts:
A protein synthesis assay was carried out in vitro. A
  polyribonucleotide containing U and C in proportion 1:5 (positions of
  U and C are random) was used as a template. Which amino acids and in
  what proportions will be incorporated into the synthesized polypeptide
  molecules?

  А. 1Phe : 5Pro : 3Leu.

  B. 1Leu : 1Pro : 1Ser : 1Phe.

  C. 1Phe : 5Ser : 5Pro : 5Leu.

  D. 1Phe : 25Pro : 5Ser : 5Leu.

  E. 5Leu : 5Pro.

First thing I am not sure is whether only U and C is there. I have tried solving this sum taking both the conditions into consideration . I also tried solving it from options but could not succeed.


texts:
If any given molecule is polar, and is capable of hydrogen bonding, I can be sure that it's hydrophilic.

However, are those two the only conditions that make a molecule hydrophilic?


texts: The meaning of the "Score" in ScanProsite

texts:
I'm doing some research about a proteïne which is sequenced, however Í'm not able to find any information about the score which ProSite scan shows after finding an possible domain profile.

I have read the prosite help, however there isn't anything which explains what the score means.


texts: Insect Identification Request - Is this a Satin Moth or something else?

texts:
Date:     July 2, 2018
Time:     11:00 AM
Location: Minneapolis MN
Size:     Approx. 1" from head to tail

I saw this moth at work today. I wasn't sure if it was just a Satin Moth, an albino (it seems to have some pigment), or something else. It fluttered over to the door and landed there to rest. A few minutes later it disappeared.

I would really appreciate some help identifying it. Please comment if I need to add additional information.


texts: Best way to automatically link Gene Entrez ID with Gene Symbol in TCGA

texts:
I am trying to figure out how to link Gene Entrez ID with Gene Symbol, for TCGA dataset.

So far, I have found this ftp directory with Gene info updated daily.

But, for Entrez ID 728661, I have found two different mappings:

here symbol is RP11-345P4.4;
here, and in gene info downloaded from ftp above, symbol is SLC35E2B while RP11-345P4.4 is in the field 'locus tag'.

Since I am a newbie I am bit confused about this thing. And, while I think they can be synonyms, I need to know if there is a best practice to use in this case, and if I need to implement some script on my own to do it automatically.

Thanks


texts: Rapid Decomposition Of Fruits & Vegetables During Hurricane

texts:
A very strange thing (To my mind) has just happened in my home. On the eve of Hurricane Irma, I purchased some food including cucumbers and grapes. I left them in my kitchen area overnight. When I woke up the next day, the hurricane was overhead. I went into the kitchen and noticed a large puddle of water on the floor that smelled of cucumber. The bag I had left the cucumbers and grapes in was at the center of this puddle.

I opened the bag and saw that the cucumbers and some of the grapes had completely disintegrated. It wasn't as though they had decomposed in any normal way. There was no visible fungi and the cucumbers didn't look especially rotted, just mostly gone. Only a small portion of the cucumbers remained. Many of the grapes were in a similar state.

How is this possible? When I bought this produce, it was fresh, not old. They had been reduced to almost nothing in less than 24 hours. I tried researching possible causes for rapid decomposition but normal decomposition of a cucumber (To this point) takes several months. I wasn't able to find a single article or time-lapse that reflected my observation. I've always been very interested in mycology so I set out to find a fungus that might be responsible but I have as of yet been unsuccessful. Could the pressure of the atmosphere during the hurricane have played a role?

If anyone can explain this, I would love to know what happened. Do I have some rare fungi floating around my house? Should I be worried?


texts: What is the difference between meristem and bud?

texts: Keep reading both terms quite frequently while studying plant physiology. I did some research trying to establish their differences and I learnt that meristems are undifferentiated cells that can generate more cells that eventually could grow to form any part of the plant. But I really mess up both concepts, so I would really appreciate a comprehensive explanation of both of them separately. Thank you in advance for your help!


texts: Difference in multicellularity between prokaryotic and eukaryotic organisms

texts: As most prokaryotic organisms are single-celled, and in eukaryotic organisms this is the reverse, is there some evolutionary advantage that led to these features evolving? Or is it purely the fact that features of eukaryotic cells allow functions (i.e. enabling multicellular organisms) not possible in prokaryotic cells?


texts: How does further hybridization affect fertility?

texts:
Numeruous scientific sites state that hybrids (like mules) are infertile. On the other hand, ligers are known to mate with both tigers and lions and still have viable offspring.

So my question is: if the hybrid is fertile in the first generation, does further mating with either of the parents' species somehow affect its offsping's fertility?

For example: if liger mates with tiger let the odds to produce viable offsping be 50%. If this offsping further mates with tiger, are odds the same or are they lower / higher?


texts: When we have eaten well and take fat rich diet then in this condition Acetyl CoA produced from fatty acid breakdown will be gone to storage in adipose tissue or not? If it will go for storage then why and if not go for storage then what will be reason?


texts: Is the inhalation of ammonia a possible health problem for bats in an artificial small volume winter roost?

texts:
About 70 bats (Nyctalus noctula) spend their winter in an artificial small volume (0,050 cubic meters) winter roost located in the attic of a building. There is a single small exit to the outside directly from the roost. The roost has been cleaned before winter from bat droppings.

Is inhalated ammonia from bat droppings a potential health risk for them?


texts:
I really fail to understand Hardy-Weinberg equilibrium and can't find an easy enough source of information.

Can you help me to understand Hardy-Weinberg equilibrium?

My goal is to be able to solve the following kind of problem

  In a population with two alleles for a certain locus, B and b, the allele frequency of B is 0.7. What is the frequency of heterozygotes if the population is in Hardy-Weinberg equilibrium?


texts: How correlated are proximally related CpG sites in human DNA?

texts:
Cytosine residues in DNA that can be methylated (i.e. CpG sites) are likely to be in the same methylation state if they are geographically (proximally) close together.

I can only find one paper that states this empirically (1), that 90% of CpG sites within 50bp of one another are in the same methylation state - see below graph.

However this study is quite dated now (in the fields of epigenetics at least), and is very general.

I would like to know whether CpG's in different regions of the genome are more/less likely to be correlated than in other regions (say, exons vs. promoter regions). It would also be interesting to know whether the correlations change with age, and whether this is related to any disease processes?

Thanks for the input.

Eckhardt, et al, 2006. Nature Genetics. doi: 2010.1038/ng1909


texts: Long term storage of agarose-ethidium bromide gels that have already been cast

texts:
I have come up with what I thought was a clever idea: Store the agarose gels I pour, and only cut as many lanes as I need to run later, minimizing wasted agarose (and wasted effort/time) when I need to make many electrophereses using a small number of lanes.

I realized that over time, the EtBr would diffuse out of my gel into the buffer that the gels are kept in. Since I add 2 µl of EtBr to 50 ml gel, and the gels were kept in 400 ml TAE buffer, I added 16 µl EtBr to the buffer, reasoning that now concentrations are equal and no net diffusion will take place.

However, after several weeks, I noticed that the EtBr signal from the gel is severely weakened. What can I do to fix this? I can see the following options:

Use higher concentration of EtBr in the buffer (how much?)
Change buffer weekly, adding fresh EtBr every time
Cover the transparent container with aluminum foil to prevent hypothetical photobleaching

Which one is most likely to solve my problem? Should I just give up, and throw away gels that are older than a day or two (I want to avoid this option, because of the record keeping needed to track when the gel was last made)?


texts: Why are diseases generally specific to a particular species

texts:
"Zoonosis" is the process of transmitting a disease from an infected animal to a human. This suggests that animal-to-human transmission is not common. HIV is believed to have first spread to humans zoonotically, but has since mutated to a human-only strain.

This all raises the question: Why do diseases mostly just target a particular species? Aren't most metabolic processes very similar across species, especially within the same order and class? Dogs and cats can't catch the common cold, but they have similar diseases of their own.

There are obviously enough similarities that mice can be used in preliminary tests of human drugs, but the results are very tentative until human trials are done.


texts: What does the point in the middle between two numbers mean?

texts:
[...] cells were removed to a cover glass and treated with plasma for 2 min, then returned to TS broth and centrifuged for 10 min. Cells were harvested and washed twice with PBS, then mixed with tryptic soy agar. The agar block was fixed with 2·5% glutaraldehyde in 0·1 mol l−1 PBS. Samples were postfixed in 1% (w/v) OsO4 in 0·1 mol l−1 PBS for 2 h at room temperature, washed once with the same buffer, dehydrated in a graded ethanol series and embedded in low‐viscosity medium. Thin sections of the specimens were double‐stained with uranyl acetate and lead citrate...

What does mean this bolded point? Is it a decimal separator, or has other scientific meaning?

If this is decimal point, why is vertically middle aligned?

Source: a recent Korea researchers team article


texts: Why doesn't Diabetes cause death by starvation?

texts: The main cause for diabetes is lack of insulin in the body. Insulin is the hormone that allows body cells to absorb glucose from the blood. With out insulin, the body cells can't get glucose from the blood. So, why doesn't diabetes cause death by starvation?


texts: Which inflammatory response with Cytomegalovirus infection?

texts:
I am thinking about inflammation process with Cytomegalovirus infection.
I first thought it is about chronic inflammation, but then changed my mind because of virus infection.
I think cytokines must be there in activation.

I am thinking which of these is right mechanism for both of these

mononuclear cells and granulocytes (I think this must be chronic inflammation)
granulocytes with scar formation (I think no scar)
cytopathic cytoproliferation inflammation

I think the cytopathic cytoproliferation inflammation is the right one because cytokines are activating the inflammatory response in virus infection.
However, I am not sure if this inflammation is of chronic type.

Which type of inflammation can cytomegalovirus infection lead to?


texts: Is there an "evolutionary species similarity calculator"?

texts:
Is there a website where I can input pairs of species and get an "evolutionary similarity score"?

E.g. (numbers are completely made up)

Input: Chimp and Human, Output: 97%
Input: Cat and Human, Output: 85%
Input: Is Cat closer to Human or Chimp, or Snake, Output: Cat is closer to Chimp (87%), second is Human (85%) and Snake is last with 50%.

I have no idea what the actual scale should be, but I imagine there is at least one interesting scale, perhaps several.

Cross posted to Quora


texts: Reducing the Proportion of Phenotype in Hardy Weinberg Population through Selection

texts:
I was given the following question:

You travel to an unknown island and find a population of strangely colored
slugs! Upon close investigation, you notice that 16% of the slugs have a
shriveled tails, a most terrible condition you decide to name Yilunemia. The condition makes the affected slugs have a 50% chance of surviving to
reproduce. This is a autonomic recessive condition caused by a single gene,
and heterozygotes are not affected.

Assuming Yilunemia confers no discernible evolutionary advantage, how
many generations should it take for the proportion of slugs with the Yilunemia disease to fall below 5%?

Possible answers:

5
6
7
8
9

I've tried to apply usual formula for frequency after selection:

0.36 + 0.48 + 0.16 = 1

0.36 + 0.48 + 0.5 * 0.16 = 0.92

Divide by 0.92 gives:

0.39 + 0.52 + 0.087 = 1

If I keep doing this, after the 3rd generation, the frequency of Yilunemia condition is 0.045, which is less than 5%. However, this isn't an answer choice, therefore I must be doing something wrong.

Any suggestions?


texts: Why do some moles grow longer and darker hair than the rest of the skin?

texts:
In different parts of the body I have skin moles or in medical terms, nevus.
In some of them hair grow seemingly either darker/thicker (I'm not sure how much of the two) and notably longer. Here are pictures very similar to what happens. What is the reason behind this?


texts: Why is oxygen and CO2 measured in pressure instead of mmoles/L like other ions?

texts: Na, K, Cl...All measured in mmol/L in plasma. Why is oxygen and CO2 measured in pressure (mmHg)? (I guess it has something to do with them being bound to RBC but I don't know why the difference).


texts:
We become numb when there is short supply of blood to some parts, as mentioned here.

If that is the reason, why don't neurons and other cells die at that part if they don't receive oxygen and other things needed?


texts:
I just have a quick question regarding what my textbook says. I have tried searching online but I have failed to find an answer. Basically, my textbook states that arterioles are smaller in diameter compared to arteries but have a larger lumen. Isn't the diameter measured across the lumen? So how can the artery have a smaller lumen but be larger in diameter?

Thank you


texts: How to explain Genome, Genes, RNA and protein in one figure to non-biologist?

texts:
I have a presentation to do where non-biologist are attending. In order to introduce a little bit my work I have to do a quick summary on genomes. So what is a genome, a gene, an mRNA and a protein. And the best would be to have that in one figure, an easy to understand. I found this : http://dnamismatch.com/Test/wp-content/uploads/2013/07/Genes-and-genomes.png

Anyone knows other resources ?

Thanks


texts: What is the name of this about 10cm high, grey, "flat hat" fungus?

texts: I found this fungus on Corsica (France). Can you please help me to identify it?


texts: PCR efficiency or DNA yield with single primer

texts:
How to calculate number of DNA molecules synthesized after 'n' no. cycles with single primer (either only forward primer or reverse primer)? Is there any formula to calculate the DNA yield after such PCR?

Supposing, I am setting a PCR reaction for 100 template DNA molecules for 30 cycles, with only one primer - forward primer for target gene. How many DNA molecules will be generated at the end of 30 cycles. All other conditions remain the same.

Thanks.


texts: Is it possible to see the microbes on your hand without using UV light or a microscope?

texts: I know that black light (UV) is often used to see the microbes (colloquially referred to as germs) on people's hands but is there any way by which we can examine the microbes on people's hands without having the surroundings be completely dark (what is required for black light to work) or using a microscope? I am trying to show a roomful of people the microbes on my hand but the surroundings aren't going to be completely dark and there is no way I can use a microscope.


texts: What are the common methods to estimate additive genetic variance?

texts:
Additive genetic variance can be estimated in a number of ways, and is a key concept in evolutionary biology and quantitative genetics.

What are the typical methods (experimental designs) used to estimate this variance? How are they done?

I found papers such as this, which use paternal half sib breeding designs and the fit a model to estimate genetic variance and then multiply the values by 4 to estimate the G-matrix.

  Of particular importance is the sire-level covariance matrix because, when multiplied by four, it provides an estimate of G.

I am interested in this because I am working on hemiclones and want to think about the differences, strengths, and weaknesses of classical methods compared to hemiclonal analysis.

*note, I mean to estimate the standing additive genetic variation within a population


texts: Peak-calling in CLIP: What is the effect of RNA-concentration?

texts:
I hope it's ok to repost my question from 8 months ago from StackExchange:Bioinformatics, that is still in beta.
https://bioinformatics.stackexchange.com/questions/10730/peak-calling-in-clip-what-is-the-effect-of-rna-concentration

Question:
I would like to ask how RNA-concentrations influence the diverse CLIP peak-callers in their evaluation of peaks. The peak-callers I would like to understand are: Piranha, CIMS, Paralyzer and the one used in eCLIP (CLIPper). (After weeks of literature research I still can't find an answer!)

More details:
If the concentration of an RNA is too low it can't be cross-linked to the tested protein and no cross-link-peaks will be found, independent on the peak-caller and independent on whether there would be physicochemical interaction hot-spots (peaks). (obviously)
But what is the consequence of increasing the RNA-concentration from a "sufficient", to a high or extremely high level?
Which of the peak-callers will find more peaks on an RNA, the higher it's concentration and which peak-callers could be considered to be robust? (Robust in a sense that the score of the peaks is independent of the RNA concentration. Also the number of called peaks of a particular RNA-protein interaction depends mainly on the number of "real interaction-hotspots" and would not necessarily increase with concentration. )
Also let's assume the interaction frequency/density is quite uniform (no physical hot-spots): Then which peak-callers would almost necessarily start calling (more) peaks, the higher the concentration of the RNA was in the experiment?

Some considerations:
I know that there are many RNAs that don't interact with any proteins (in the databases) and that there are some RNAs that interact basically everywhere throughout their sequence to almost all tested proteins. (Potentially this is observed due to concentration dependencies!)
CIMS & Paralyzer, to my understanding, take the fitted crosslink-induced mutation rate at the specific sites to evaluate peaks. This ratio (mutated/total), in theory seems robust to me.
Piranha, as I understand, tries to fit the raw data to a sum of many individual binomial-functions, basically assuming the bulk of reads as background noise, only evaluating local peaks in read-counts relative to the background. This seems robust to effects of very high concentrations.
I would be thankful for any comments or references!


texts: What is the function of the RNA primer in DNA replication?

texts: During DNA replication, RNA primase puts an RNA primer in the lagging strand. What is the function of this RNA primer? Why can't the enzymes put DNA fragments directly?


texts: Are free-nuclear division and endomitosis the same?

texts: As far as I understood it, both are cases of karyokinesis, not followed by cytokinesis.


texts: Is it correct that the body only responds to the most painful stimulus?

texts:
I'm rather ashamed to say that this question is partly based on an episode of House.

I have previously heard that, if there are multiple simultaneous painful stimuli, the mind will only feel the sensation of pain from the most severe injury.  A large amount of googling has turned up nothing and PubMed searches are proving tricky as I cant find the name of this effect (if it exists).

If it does exist, is the mechanism solely effective for pain signals or would we for example only feel cold at our coldest points (i.e. from the face or the hands rather than both) on a frosty morning?


texts:
I've read that SARS-Cov-2 has several variants, e.g.:

Can the U.S. keep Covid variants in check? Here's what it takes.
Novavax’s Vaccine Works Well — Except on Variant First Found in South Africa

When does one decide to refer to a virus as a new variant?

My research:

I looked at https://biology.stackexchange.com/questions/tagged/variant?tab=Votes
The question What determines when a virus becomes a “new strain”? addresses strain. Is strain the same as variant?


texts: I was reading about bootstrap in phylogenetics and it got me wondering that amongst all of the methods (UPGMA, Maximum Likelihood, Parsimony, Neighbour joining method) which method generally provides the largest bootstrap support? Or does that vary from problem to problem?


texts: There was some experiment in which a S phase cell was fused with other cell and the other cell also began to replicate DNA. Would the same happen if fused with nerve cell ? Why or why not?


texts: Here is a question I've never asked myself until now: All textbooks show synapses with a decently large synaptic cleft between the axon terminal and the dendrite. How is this connection held in place mechanically? How is the axon terminal attached to the dendrite?


texts: Is the primary evolutionary purpose of a fleshy fruit to benefit the sprouting seed or the frugivorous seed disperser animal?

texts:
In a question about the low protein content in fruits, one answer suggests the energy, carbohydrate, and protein content in a fruit evolved to entice animal seed dispersers, not foster the sprouting seed.

Another answer suggests plants are made mostly of cellulose, hence why the fruit has more carbohydrates than protein. The implication here is that the content of the fruit is optimized for the benefit of the sprouting seed, which is constructing a plant, not an animal.

It seems like it would be an easy answer to prove experimentally: plant two seeds in nutrient-poor soil, one with its fruit whole, another with its fruit mostly eaten (or even entirely passed through an animal's digestive tract). Then see which seeds thrive better.

Obviously fruits cultivated for human consumption have had their evolutionary course commandeered for benefit of the frugivore. And to a lesser extent probably many plants have a symbiotic relationship with their seed dispersers. But is that relationship an enhancement of the primary evolutionary purpose, or an enhancement?


texts:
I am not sure this question belongs in biology, but I can't find a more suitable stack exchange site, feel free to delete it if this doesn't fit here.
Also, this question is going to be slightly gross, just a warning, but I promise it comes to a point.
I have read that the adenoids have a texture to them but, unlike say the palatine tonsils, they don't have crypts.
Last year my palatine tonsils became fairly badly infected and had to be removed over the summer. Before the surgery, I discovered I could reach back to the tonsils with my tongue, enabling me to remove the tonsil stones that built up. Gross, I know, but I believe it actually did make the infection noticeably better. After the surgery, and after the area had healed, I resumed discovering the back of my throat and, eventually, up the nasal cavity, all the way to the back of the nasal septum, which means I can reach the Eustachian tubes, adenoids, and posterior nares. If that sounds impossible, I assure you, it is perfectly achievable, and only mildly uncomfortable. With my tongue I can feel the texture of the adenoids but, more toward the posterior nares, this texture changes and resembles folds or crypts like I remember the texture of the palatine tonsils. Three times, always in the morning after waking up, I have discovered debris in this region strongly resembling tonsil stones but green instead of off white. The mucus, however, is always clear.

My question has several parts:

What are these crypts? Are they even crypts at all? Are they part of the adenoids?
Why can I not find mention to these structures in any diagrams or medical articles?
Why can I not find mention to tonsil stone like debris except in the palatine tonsils? I am quite convinced that, if these are not tonsil stones of a sort, they are closely related.

The proportions of diagrams and cross sections of the nasal cavity all seem wildly different. Some of them are just blatantly wrong, depicting, for example, the Eustachian tubes coming from the roof of the nasal cavity instead of the sides. It has been very difficult to find good information on any of this. I am not even sure if I am referring to the region correctly. By nasal cavity, I mean everything between the back of the throat and the posterior nares, although I am aware the nasal cavity includes the region all the way up to the anterior nares as well.
This is the only picture I can find that shows the nasal septum.

This is a better diagram of the rest of the structures. The pharyngeal tonsils are the adenoids.


texts: What drives max heart rate on beta blockers?

texts:
In a healthy human being, the increase in heart rate from rest to around 100 to 110 beats per minute at low intensity exercise is due to withdrawal of the parasympathetic nervous system's influence. If exercise intensity increases beyond that point, the matching increases in heart rate above 100 to 110 beats per minute are due to sympathetic nervous system influence.

There is a transition range around 100 to 110 beats per minute where the intrinsic rate of the heart beat is determined by the body's metabolic activity.

However, when a person takes a beta blocker, the sympathetic influence on the heart rate is attenuated, so that the person's max heart rate is lowered to around 110 beats per minute.

What is driving the heart rate at high intensity exercise in patients who take beta blockers?  Is the heart rate around 110 beats per minute in patients on beta blockers driven primarily by the metabolic influences in the blood? What other factors are influencing heart rate around 110 beats per minute in patients who take beta blockers?


texts: Why don't we consciously know how our bodies work?

texts:
Our brain is responsible for regulating our entire body. However, we don't consciously know how our bodies work — our brain has to learn about biology, medicine, and so on.

Since our brain controls our bodies at the cellular level and below, why do we still have to learn about these processes to become doctors, biologists, etc.? Shouldn't we born knowing about them?


texts: Could fingerprints potentially be changed using a gene gun?

texts:
Not to confuse with your "DNA fingerprint"  I've read surgery is readily used to not just remove but even to change people's prints through employing very small grafts between opposing hands.

About 5 years ago a Chinese group identified SMARCAD1 as a key player in the development of fingerprints. this was  discovered by generating gene expression profiles of people with a very rare condition called adermatoglyphia. These people have  no finger prints.

A gene gun, which uses micropartical bombardment is a technique that propels microscopic particles of heavy metals, coated with the gene of interest, "deep" into tissues.

If you were to alter the genetics of the epidermal stem cells, you could potentially permanently change the tissue that arises from those stem cells. Could this in principle work if over expression of SMARCAD1 resulted in remodeling of the prints or has other more important genes been shown since to be involved?

Do any model organisms have fingerprints, or a version thereof?

I know I'm fishing here, lots of questions. I thought it was an interesting topic and wanted to see what people here had to say.


texts: Any studies on the effects and/or benefits of oil pulling?

texts:
A friend recently recommended me a process called 'oil pulling' for my teeth as I am struggling with my dental health at the moment. The process involves using a tablespoon of some kind of vegetable oil (like coconut oil) and swilling it around in your mouth for 20 minutes without swallowing. This supposedly acts as an anti bacterial and pulls toxins out of the body and helps with dental hygiene.

Are there any studies demonstrating or refuting its validity? Any help would be much appreciated.


texts: Is it correct to use the terms multinucleate and syncitia interchangeably?

texts:
If you see the skeletal muscle,it is having several nuclei and is said to be "multinucleate".Similarly the cardiac muscle is also having several nuclei yet it is specifically termed"syncitial".So my question is: Is there any reason behind this or are the terms interchangeable?
I am listing the sources from which the question came up in my mind:
[Source1]

Individual muscle fibers are formed during development from the fusion of several undifferentiated immature cells known as myoblasts into long, cylindrical, multi-nucleated cells. Differentiation into this state is primarily completed before birth.[Source2]
The cardiac syncytium is a network of cardiomyocytes connected to each other by intercalated discs that enable the rapid transmission of electrical impulses through the network, enabling the syncytium to act in a coordinated contraction of the myocardium.[Source3]


texts: This unidentified animal was trapped in northern part of Kerala State India and images circulated through social media. Doea anyone know what species this is?


texts:
I saw on TV that not all sperm are the same. Some have mutations like 2 and 3 tails?  There were other mutations as well.

If one of these mutated sperm actually fertilized an egg, would the embryo be mutated in some form or fashion?


texts: Why is there a mass limit on biological powered flight?

texts:
So, this is a thing I never fully understood. There are a lot of reasons for a flying creature to be limited in mass (though I'm unsure if I'm familiar with all of them), from energy consumption to material strength. However, there seems to be an argument that goes along the lines that over a certain mass, no matter what, they can't generate enough power to counteract gravity.

What limitation could they exactly mean with that?


texts: How do you calculate or predict the charge of a protein at pH 7?

texts:
How do you calculate or predict the charge of a protein at pH 7 given a fasta sequence?

Any papers or online servers to do this is well appreciated.


texts: Does Amphibian embryo's blastocoel become a primitive yolk sac without yolk?

texts:
The mammalian blastocoel becomes yolk sac without yolk according to my professor. I have not found any evidence that such a thing happens in amphibians like frog.

I need to be able to compare and contrast cleavage and formation of blastula in amphibians and in humans.
My thoughts raised another question.
My friend says that blastula exists only when blastocoel exists.

2. Is the thing without blastocoel but with yolk sac the blastula?


texts: What determines the shape of the center-surround receptive fields of retinal ganglion cells?

texts:
The wikipedia article about receptive fields of visual system tells us the following:

  The receptive field is often identified as the region of the retina where the action of light alters the firing of the neuron. In retinal ganglion cells (see below), this area of the retina would encompass all the photoreceptors, i.e., all the rods and cones in the retina.

Then it shows some pictures

I understand the part where it says that the neurons firing increases as we put light on the center of the receptive field (for ON center type) and etc.

What I'm not sure about is the location of this circle; where is this circle that we put light on?

What I think might be the answer is that, as the quote says, the circle is the area of retina where we have the rod/cone shaped photoreceptors.

So this means that, for every ganglion cell, the photoreceptors connected to it are always shaped like a circle?


texts:
By "dream", I mean:

Dreaming while sleeping.
Dreaming about their future life while being awake.

Thank you in advance.


texts: Is my cell-culture contaminated with mold?

texts:
I am growing cell cultures at the moment, and I sometimes find 1-2 of these elongated, black structures in one of my 8 wells. Should I be concerned?

I have been growing these for about 5 days at this point, replacing the media every the other day. I figure that the life-cycle of mold is pretty fast, and that if it were truly mold that it would overpopulate the well pretty quickly. Perhaps it's just debris?


texts: What is the functional and structural distinction between core (H2A, H2B, H3,H4) and linker(H1/H5) histones?

texts: Many explanations of histone biochemistry isn't quite elucidating for the undergraduate student. How does histone structure (dimers, octomers) relate to their specific functions as core or linker histones? Also, how do both linker and core histones interact within nucleosomes to ultimately regulate gene expression?


texts:
I could not spell the agar [gonoline-uroline] which I heard yesterday.
My spelling is so wrong that I could not find it in Google.

What is the right spelling for this agar?


texts: Are there differing organelle to cytoplasm ratio in animal cells?

texts: Could anyone provide me with examples of cells with high organelle to cytoplasm ratios (heavily packed), and examples of cells with low organelle to cytoplasm ratios (sparsely packed)?


texts: Will humans ever evolve to cope with the rising temperature of our planet?

texts:
I am a complete layman of this field(Biology).I went through an article about global temperature rise and i wanted to ask this question.

  Federal science agencies announced Wednesday that 2016 was the warmest year on record, beating the previous record of global temperature set in 2015, which had beat the previous record set in 2014.

(As seen in the graph temperature is rising rapidly and will increase even more in the near future.)

Can we evolve to cope with high temperature?Will we evolve?Is mutation the only answer?

(Frankly not looking for an answer saying by natural selection,the last thing i want to hear)


texts: Which method of seed dispersal is the most common among the seed plants?

texts:
The five most common methods of seed dispersal in the plant kingdom are:

wind (anemochory): tumbleweeds, dandelions, maples
animals:(epizoochory) externally - burs / (endozoochory) internally - fruits
water (hydrochory): aquatic-water lily/terrestrial-mangrove trees
gravity (barochory): apples, coconuts
ballistic (ballochory): impatiens, geraniums

source: https://en.wikipedia.org/wiki/Seed_dispersal

As far as which one of these five is the most common, this site says that animal dispersal is more common than wind but nothing in relation to the other methods listed above.  Each method likely is most common in it's most well suited niche, but which one is the most common (in the widest range of species) overall?


texts:
I have learned (probably in high school?) that hairs turning white is caused by the part of the folicle which produces the pigment dying and being replaced by an air bubble. This sounds very irreversible.

I have long dark brown hair, and since I turned 25, I have had a few white hairs here and there. It is not unusual to find hairs which have a dark tip but are white at the root, which fits the above theory.

But I also have hairs which are the opposite: the lower ten centimeters are pure white, but at some point, there is an abrupt transition to dark brown, and the hair is dark again up to the root. This is all a natural phenomenon, I haven't used dyes or bleaches.

So what makes white hair white, if it can turn back to dark? Why would a single hair turn back?


texts: Is it PSI-BLAST or BLASTP if I use PSI-BLAST for only one iteration

texts: In my case, I used PSI-BLAST in the local BLAST+ to search queries against the self created database. After the first search, I added the searched result to the database and then conducted the multiple sequence alignment myself with MUSCLE to get the conserved parts. Then, I searched the queries against the consensus sequence obtained from the multiple sequence alignment (without gap). In this process, I did not calculate a PSSM, while the first iteration of PSI-BLAST uses a constant matrix, which is much similar to BLASTP. So what did I actually use in the process – PSI-BLAST or BLASTP?


texts: Same primers and different melting peaks for two samples (~1°C appart)

texts:
In the figure, you can see that melting peaks differ by ~1°C at each sample.

Should I be worried?


texts: Resource for finding Repressive/Inhibitory factors for a given gene?

texts:
I have a list of genes for each of which I'd like to find:

A list of transcription factors that up-regulate the gene
A list of inhibitory factors that down-regulate it.

I used this tool on Qiagen's website to find transcription factors (and will be thrilled if someone can share a better tool). Its less than ideal for my purposes because I need to search each gene individually and there doesn't seem to be anyway of downloading or copy/pasting the transcription factors it returns; but it works.

What I really need now though, is a way to find inhibitory factors by gene. Does anyone know how I can do this?

I have already tried using  wikipathways and found it to show almost none of the transcription factors I found on Qiagen's website leading me to conclude that their data is far from comprehensive. I have applied for access to Ingenuity only to discover that I will not be granted access soon enough to make use of it.


texts: What is meant by Physarum polycephalum having 720 sexes?

texts:
There is currently some media hype about the slime mold Physarum polycephalum, which will soon be exhibited in the Paris zoo. This was my first time hearing about slime molds, but so far so good.

What I don't understand though is this organism supposedly having 720 sexes. This seems strange to me, as to my – admittedly layman's – knowledge, single-celled organisms like this one aren't supposed to have sexes at all, reproducing instead through cell division. It looks to me like pretty much all newspapers reporting on this have no idea either and decided to just keep it because it sounds interesting. On Wikipedia, nothing is said about hundreds of sexes at the time of writing.

What does this actually mean?


texts: Can any gas other than nitrogen cause decompression sickness (the bends)?

texts:
I know that our bodies use most of the oxygen we breathe in during a dive but, wouldn't our tissues, under pressure, absorb more oxygen than we need?  For instance, in normal circumstances, we don't use all the oxygen in each breath and we exhale some (this is what 'rebreathers' are for, right?)
Couldn't any gas we breathe in under pressure cause decompression sickness when we decompress?
Read this, from NASA:

"Astronauts put on their spacesuits several hours before a spacewalk.
The suits are pressurized. This means that the suits are filled with
oxygen.
Once in their suits, astronauts breathe pure oxygen for a few hours.
Breathing only oxygen gets rid of all the nitrogen in an astronaut's
body. If they didn't get rid of the nitrogen, the astronauts might get
gas bubbles in their body when they walked in space. These gas bubbles
can cause astronauts to feel pain in their shoulders, elbows, wrists
and knees. This pain is called getting "the bends" because it affects
the places where the body bends. Scuba divers can also get "the
bends."


texts: Why is the hexose monophosphate shunt called a direct oxidative pathway?

texts:
Why is the hexose monophosphate shunt (pentose phosphate pathway) called a direct oxidative pathway( Ref. Biochemistry by Satyanarayana , 4th edition, pg.no: 244) , even though oxygen molecule is not used for oxidation? It uses NADP for its oxidation. So if utilisation of NADP is direct oxidation then what will be indirect oxidation?
How can I differentiate direct and indirect oxidation? Is the use of Electron transport chain considered as secondary oxidation?


texts:
Is there any virus, either natural or engineered, known to infect yeast through mechanisms similar to phages/human viruses, that is, by horizontal contamination mediated by extracellular viral particles?

I have found examples of eukaryotic viruses replicating in yeast (Zhao, Microb Cell, 2017 - link) but it seems that natural yeast viruses only transmit through mating or vertical transmission, without extracellular steps (Luque, Viruses, 2018 - link).

Has anybody ever reported, say, non-specific mechanisms like VSV-G mediated fusion, to fuse virions with yeasts?


texts: Some common medicinal preparations contain diazepam with aluminium Hydroxide, there may be other compounds [e.g. magnesium trisilicate and polydimethylsiloxane with Aluminum Hydroxide and Diazepam as ingredients of Tablet Peptica ( Geno pharmaceuticals)]. These drugs are commonly used as antacids. We can see in the drug Peptica that Aluminum Hydroxide and Magnesium Trisilicate were included for neutralizing the acidity (HCl) of stomach.....thus serving their purpose as antacids. Polydimethylsiloxane is a carminative preparation ('Carminative' means preparations that expulse gas from the gastrointestinal tract or prevent its formation). But what is the need for adding Diazepam here?


texts:
I am doing a project on microbial fuel cell. For the purpose of the efficiency of the question, MFCs can be summarized to:

  Devices that use anaerobic bacteria as the catalysts to oxidize organic and inorganic matter and generate current. I referenced this article

While writing the analysis I was quite confused about the fermentation process in which anaerobic bacteria in soil undergo. Usually the fermentation process and its byproduct would be specified, however, in this case there are numerous bacteria that the soil contains.

I want to ask if there is a specified fermentation process that the soil bacteria undergo (which is probably not the case), or is it unknown so I should just talk about fermentation in general.

Thanks in advance!

ps. it would be greatly appreciated if a link to some websites or articles that would possibly help me is included :)


texts:
According to the endosymbiotic theory, mitochondria are descended from specialised bacteria (probably purple nonsulfur bacteria) that somehow survived endocytosis by another species of prokaryote or some other cell type, and became incorporated into the cytoplasm [ref].

And plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes [ref].

I was however taught that mitochondria have no plasmid and only have circular DNA. If the endosymbiotic theory is true, then how come mitochondria have no plasmid?


texts: Energy efficiency of muscles and animals as a whole

texts:
When human or animal do some work, they use energy from their food. What is known about overall efficiency of this process?

Say a horse is turning a winch and does 10,000 kJ of work. How much more food will it eat to sustain that effort (compared to when it just stands around)?


texts: How does sunlight affect the longevity of SARS-CoV-2 on surface?

texts:
UV radiation is known to degrade most viruses rather quickly.  How does the UV radiation from sunlight affect the longevity of SARS-CoV-2 on surfaces.

Of particular interest to me is the virus' lifespan on gas pump handles, which are typically in covered but open spaces.


texts: Identification for a bird in the middle of the tree

texts:
In the central city of Dobrich Bulgaria, I was following a Great spotted woodpecker in a tree and suddenly I found this other bird on the same tree.

The context of the picture is:

Country: Bulgaria
City: Dobrich, Center urban area
Period: mid August (2016)

I think this is a specimen of Silvia Curruca, can anybody confirm this?


texts: T cells are formed in bone marrow and mature in Thymus. How are they transported from bone marrow to thymus ? Through the lymph vessels ?


texts: Is UV radiation more likely to cause mutations during mitosis?

texts:
According to Life: The Science of Biology (10th edition), UV radiation might cause the formation of pyrimidine dimers, which are the primary cause of skin cancer in humans.

Are mutations more likely in case a cell is exposed to UV during mitosis?

My TA (who is a stem cell researcher) implied that the answer is yes, as she explicitly said that the risk of getting cancer from gel manicure is non-trivial, due to the following reasoning:

During the treatment, small cuts are made (not on purpose) to the skin around the nails.
The exposure to UV occurs just after that, while the tissue is healing.
This significantly increases the risk of cancer.

However, I didn't find information about that by googling. On the contrary, I encountered studies about using UV to enhance healing of wounds, e.g., Is UV radiation beneficial in postburn wound healing?.

In addition, Wikipedia's scar page says (though I didn't find a reference for that claim in the Wikipedia page):

  scars in the skin are less resistant to ultraviolet radiation

Also, people are instructed to avoid exposure to UV after laser hair removal.

Is these two related to mitosis? Or are they instead related to some property of scar tissue?

references:
Rennekampff, H-O., et al. "Is UV radiation beneficial in postburn wound healing?." Medical hypotheses 75.5 (2010): 436-438.


texts:
I have read a lot about the programming language, Cello, that MIT created to program DNA; however, I cannot seem to find any sources online that shows you how to program with Cello. Are there any good sources out there with regard to this topic?

Thanks


texts: True or False: Endocytosis delivers vesicles directly to the cis face of the Golgi complex

texts:
Does anyone know the answer to this question, and also the explanation of to why this is True or False?

I know that Endocytosis is the process of uptake of materials into cells including microorganisms, solute particles, and food particles from the ECF. The Golgi Complex is the trafficking directory organelle of the cell which vesicles enter in the cis face and exit in the 'rougher' trans face. It adds tags to vesicles for target compartments. Proteins come from the rER wrapped in vesicles and directed to the Golgi Complex.

In my knowledge the membrane bound or secreted proteins are directed to the rER first, thus I am half certain that this question's answer is False.


texts: Formation of ammonia from air and moisture

texts:
On extended bicycle trips I sometimes slept under a plastic sheet, which helped with mosquitoes on hot nights. But there was a noticeable build-up of ammonia which made this almost impossible for more than an hour or so at a time.

Air is mostly nitrogen $(N_2)$ and there is always water (containing hydrogen) on a humid day. But I wonder about the mechanism for the formation of ammonia under these circumstances? There are (according to Wiki) trace amounts of methane and $H_2$ in the air. But methane and hydrogen (g) are I think pretty stable.

I wonder if the presence of exhaled air (containing $CO_2)$ could be a factor?

Thanks for any ideas.


texts:
I came across the phrase lateral septum and I can't seem to find the precise definition online. Is it "the areas roughly to the right and the left of the septum pellucidum"? Or is it the parts of the septum pellucidium itsef? I'm confused.
If it is near the septum pellucidum (to the left and right), does it include particular nuclei?

Brain pathways for sexual excitation involve the activation of incertohypothalamic and mesolimbic DA transmission in the mPOA and NAcc that focuses attention on incentive sexual stimuli and engages motor patterns of approach and consummation. Collectively, the behavioral patterns stimulated by those systems and the subjective feelings that accompany them constitute the epiphenomenon referred to as sexual desire or, when mixed with genital and sympathetic arousal, “libido.” The core of this pathway includes the mPOA and its outputs to the VTA, which contain DA cell bodies that project to various limbic and cortical regions, such as the prefrontal cortex, olfactory tubercle, NAcc, ACC, lateral septum, and corticomedial amygdala.

The article is "Pathways of Sexual Desire" by James Pfaus (2009).
I have read the Septal area article in Wikipedia but still cannot get it.


texts: What kind of spider is this? I have never seen one like this before

texts: This was on my butterfly bush yesterday with a moth by the neck.  I have never seen one like this before.  Just wondering what the name is.  This is in southern Illinois.


texts: Why Can't the passage of acquired behavior be considered acquired inheritance?

texts:
While reading about a cross-fostering experiment conducted on Male California mice and Peromyscus californicus, I came across the fact that the behavior acquired by a generation of mice due to foster-parents is transferred to the next generation as the next generation also gets the same amount of parental-care and attention as the first.

As we can say that behavior is also a character in a way (and is influenced by genes as well as environment), wouldn't the transfer of such behavior over time (if the mice bred by foster parents were positively selected for) be considered 'inheritance of acquired characters?'


texts: What percentage of the genetic variance is explained by the 'n'- most important loci?

texts:
Introduction
Standard models in population genetics look up at the evolution of few loci which impact fitness. The variance in fitness is determined by the genetic variance and the environmental variance (and the co-variance between environment and genetics). In this question I am interested only about genetic variance and about what percentage of the total (additive or not) genetic variance in fitness do 'n' loci explain.
Question
In general, in natural populations, what percentage of the total genetic variance is explained by the 'n'- most important loci?
Here, by "most important loci" I mean loci which variance explain much of the total genetic variance.
In other words, the subquestions are of the kind:

how much of the fitness variance does the most important locus explain?
How much of the fitness variance do the 3 most important loci explain?
How much of the fitness variance do the 100 most important loci explain?

Of course, the answer depends on the population under consideration. Factors that might influence the answers are for example

species
population size
environment stability
…

Beside this question, I also welcome some insights concerning how different factors are likely to influence the answer.


texts: Evolutionary advantages of wet nose of cats and dogs?

texts: Everyone knows that some animals, at least cats and dogs, keep their noses wet and cool. But why did they evolve it? What evolutionary advantages does it provide? Smell-sensing cells need cooling for precision, may be? Or the liquid dissolves smellful gases into itself, simplifying analysis this way? Or may be it just simplifies cleaning the nose from the previous sniffing act?


texts:
S. pyogenes is "flesh-eating" bacteria.
It results from life-theatening myonecrosis caused by this organism.
S. pyogenes avoids phagocytosis (mediated primarily by capsule, M and M-like proteins, C5a peptidase), adhere to and invade host cells (M protein, lipoteichoic, F protein), and produce toxins (streptococcal pyrogenic exotoxins, steptolysin S, streptolsin O, streptokinase, DNases).

Suppurative diseases: pharyngitis, soft-tissue infections.

Erysipelas: localised skin infection with pain, inflammation, lymph node enlargement and systemic symptoms.

Cellulitis: infection of the skin that involves the subcutaneous tissues.

Necrotising fasciitis: deep infection of skin that involves destruction of muscle and fat layers.

I think these are most its skin infections. But what about its diagnostics?

I think take biopsy from living tissue, not from necrotic.
If pus, then probably from it.
I think we can do Gram staining, recognise gram-positive cocci like in a string
Then, we can do hydrogen peroxide test - if no bubbles, then suspicion to S. pyogenes, since catalase negative.
The do optochin test which is positive for S. pyogenes.

What is the correct procedure for doing skin infection diagnostics for group A streptococci?


texts:
I have read a lot about the outbreak of the coronavirus, I know that in january scientists had already sequenced the viral genome.

How was the virus identified prior to the sequencing

Given that viruses are not like germs that you can see and distinguish readily in microscope, how could scientists know that there was something new about the new disease and how could they purify the pathogen that cause that disease without knowing what it is and without knowing its genetic code?

Where can I find information about procedures that are used to identify new viral pathogens?

Given that there is a group of people with suspicious desease, what are the laboratory procedures used to eliminate known pathogens and how you discover that you have a novel virus without knowing its genetic sequence (and without the ability to extract it - as far as I know you can not isolate virus particle with tweezers...).

Thank you!


texts: Program (on Mac) to show 3D protein structures?

texts:
I have an assignment for 6th grade biology. I have to look at a 3D structure of a protein and manipulate it so it only shows the AA I’m interested in currently.

what I already did
I already looked up the programs most used for this and they point me to JMol and Yasara but the download files are .bin files and the like and I don’t I don’t understand which file is the one I should download and how to install it.

Can someone help me please ?


texts:
Vitiligo is a skin disorder where the pigment disappears. More on Wikipedia. This is believed to be caused by autoimmunity and has made me interested in autoimmunity in general.  I am still very much a layman, however.

One of the characteristics of vitiligo is that it is uneven. Some patches of skin look normal, others are completely albino-like.

If the immune system has decided that skin pigment is an enemy, why doesn't it destroy all the skin pigment?

I understand that little is known about vitiligo, so I will accept answers describing similar effects in other autoimmune disorders.


texts: How do cockroaches resist the effects of ionizing radiation?

texts:
Cockroaches are very hardy insects. It is known that, among other things, they are able to withstand bursts of ionizing radiation that would kill a human being.

The explanations of this observed resistance I've seen include cell division not being that fast in cockroaches, and the relative simplicity of these insects compared to other organisms. I know that microbes are able to resist radiation by having "tough" DNA (more G-C base pairs) and ready repair systems. Do cockroaches also have mechanisms like these, or is it really as simple as them being, well, "simple"?


texts: Is Zymase, A Complex of Enzymes? Which ones?

texts:
Some websites state that the enzyme zymase (which I understand to be a complex of several enzymes) is responsible for catalyzing glycolysis in order to produce pyruvate.
On the other hand, some other websites state that zymase is responsible for catalyzing the conversion of pyruvate to acetaldehyde, and acetaldehyde to ethanol and carbon dioxide.

Which one of the above is correct? And, what are the names of the enzymes that are collectively called zymase.

I thank you for your time and consideration. Good day!


texts: What does does a blood sample tell you about an individual's identity?

texts: I am working on a fiction/mystery scene where blood is found in a particular character's residence but the character themselves is missing. I would like to understand whether the law enforcement/forensics team are realistically able to identify if the blood belongs to the missing character, without having a prior blood sample or DNA of this missing character? If not what details are they able to learn from the sample eg. gender, age, physical characteristics etc?


texts: Defining dominance and selection in these formulae

texts:
This paper uses two equations to explain the different conditions under which sexually antagonistic genetic variance is maintained in a population, while allowing for unequal dominance, for autosomally linked loci:

$h_f / 1-h_m + h_fs_f   <$ $ $ $   s_m/s_f   <  1-h_f/h_m(1-s_f)$

And X-chromosome linked (X-linked) loci:

$2 h_f / 1+h_f s_f < $ $ $ $ s_m/s_f < $ $ $ $2(1-h_f)/1-h_f s_f$

where $s_m$ and $s_f$ are the selection coffecients against the less fit homozygote (or hemizygote) in males and females respectively where the most fit genotype has a relative fitness of 1. Similarly $h_m$ and $h_f$ represent the dominance of the less fit allele in males and females, and $h_m$ is not applicable in the X-linked equation because there is no dominance (due to hemizygosity it can only be homozygote).

I'm having a little trouble understanding how $s$ and $h$ are defined here.

For $s$, is it the fitness of the deleterious homozygote or the difference in relative fitness between the two homozygotes? Such that either $s$ = the relative fitness of the homozygote, or, $s$ = 1 - relative fitness of deleterious homozygote, where one represents the fitness of the fittest homozygote thus giving the fitness differential.

For $h$, is the dominance defined as the fitness difference between the less-fit homozygote and the heterozygote, or the most-fit homozygote and the heterozygote? Or is it the deviation from the average fitness of the two homozygotes?

Going from the graph (see below for values of fitnesses), what are the values of $s_m$, $s_f$, $h_m$, and $h_f$ where the dashed line is Females and solid line is Males. I see possible values of either $s_m$ = 0.2 or 0.8 (fittest genotype - fitness of weakest), likewise $s_f$ is either 0.3 or 0.7, $h_m$ is either 0.1 (deviation from most-fit genotype), 0.7 (deviation from least-fit) , or 0.3 (deviation from average) and $h_f$ is either 0.3, 0.4, or 0.05.

The values here are, as fitnesses for genotypes A1A1, A1A2, and A2A2, for males, 1.0, 0.9, 0.2, and for females 0.3, 0.7, 1.0.


texts: Is there a closed path through the circulatory system that never passes through the liver?

texts:
I know the liver is responsible for doing lots of stuff to the blood, including both adding glucose and removing "weird stuff" (stuff destroyed by hepatocytes).  And I know that statistically every volume element of blood will eventually pass through the liver.
However, if you were magically minaturized a la Fantastic Voyage, and traveled with the blood flow, making ideal turning decisions at every arterial branching but never going upstream or out of the blood vessels themselves, could you completely avoid the liver?


texts: How many metabolites are in the metabolome of (almost) all eucaryotic cells?

texts:
Which small biomolecules (up to the size of amino acids) are present in (almost) every eucaryotic cell and thus part of its biochemical network, constantly and inevitably being produced and metabolized?

Is there either a comprehensive list (e.g. being a sublist of this one) or at least a number: How many are there (roughly)?

To ask it differently: How many small molecules are in the metabolome of (almost) all eucaryotic cells?

Side question: Does the famous Metabolic Pathways poster contain all of them, or which percentage (roughly)?


texts: Why is the number of cells virtually a constant?

texts:
Going back to highschool, I learnt about mitosis: in order to renew their cells, eucaryots' cells divide themselves into two copies.
But my course didn't cover what moderate the replication. By moderation, I mean something that prevent the number of cells to grow forever.
So here is my question:
What phenomena are responsible for the moderation of cell replications?
I did some research on my own on both the internet and SE, but couldn't find anything (maybe because I don't know the correct keywords)


texts: What could humans do to "see" what dogs smell?

texts: We're able to see a lot of things using computers that we can't see normally: yellow-green, UV light, X-rays, etc. What do we have that harnesses the ability to "see" what dogs smell (e.g., harnessing a dog's sense of smell to detect cancer and so forth)?


texts: Is viral single-stranded RNA in the absence of reverse transcriptase infectious?

texts:
In a medical microbiology textbook I'm reading (Murray et al, 1994), the authors state the following:

The retrovirus genome has a 5' cap and is polyadenylated at the 3' end. Although the genome resembles a messenger RNA (mRNA), it is not infectious because it does not encode for a polymerase that can directly generate more mRNA. The genome consists of at least three major genes that encode for the enzymatic and structural proteins of the virus: gag (group-specific antigen), pol (polymerase), and env (envelope). At the end of the genome are long terminal repeat (LTR) sequences

From this, I interpreted that because viral RNA doesn't encode an RNA polymerase, it is not itself infectious. However, if a cell were to be injected with retroviral single-stranded RNA alone, wouldn't this RNA be translated into proteins (including reverse transcriptase) as if it were normal mRNA into a protein? If this were correct, then the single-stranded RNA has all the information in itself to propagate the virus. Single-stranded RNA needs to be reverse-transcribed into the host's DNA before being transcribed into mRNA that can be translated.
Is there something different between viral RNA and the mRNA transcript that makes one translatable and the other not?
Source: Murray, Patrick R et al, Medical Microbiology (1994), Second Edition.
EDIT/UPDATE
I contacted the author of this chapter (Dr. Ken Rosenthal) and gained some more insight into how this hypothetical (injecting plain retroviral RNA into a cell) would play out. His answer is that yes producing new viruses possible but not probable. The reasoning for this is as follows:

The main reason that a new virus would likely not be created is that for the genome to make a new virus, reverse transcriptase is needed. Without reverse transcriptase, cDNA can't be made. Suppose that a ribosome was able to make reverse transcriptase with naked retroviral RNA and this newly made reverse transcriptase stayed near the ribosome. It would have difficulties making new cDNA from the original RNA template. One of those challenges is that cDNA synthesis needs a specific primer on reverse transcriptase.
The translated retroviral RNA would likely be degraded due to their finite lifespan in the cytoplasm.
There would need to be enough viral proteins translated to form a capsid. This would be unlikely considering the lifetime of the RNA in
Even if there were enough proteins in the cytoplasm, these proteins would then have to remove the RNA from the ribosome to encapsidate it. This is also unlikely.

Considering this, the microinjection of naked retroviral RNA would be an inefficient process to cause an infection.


texts: Photolysis in the Light Reactions of Photosynthesis

texts: I'm a bit confused concerning photolysis. During the light reactions, photons are used to excite the chlorophyll molecules so they are passed to the primary electron acceptor. The electrons initially come from a split water molecule. Is water split by the photons?


texts: Selection for less efficient egg transfer in Human Botfly life cycle

texts:
I have heard that the Human Botfly transfers its eggs through other invertebrates, and it strikes my curiosity that if an insect could simply land on its host directly to deposit its eggs, then why have intermediate hosts?

I have speculated that the vectors may be better specialized for penetrating hosts, and that penetrating hosts may be difficult, or that approaching hosts is risky. Another speculation on my part is that the Human Botfly may be filling a niche where it does not need to compete.


texts: Im trying to find out what type of snail this is

texts: The snail is pretty large and located in texas.


texts: The parameter for setting the number of mismatches in standalone blast

texts:
In a standalone blast search, is there a parameter that could be specified to fix the number of mismatches allowed in an alignment. I went through the parameters and I could only find parameters to set score.

-q => Penalty for a nucleotide mismatch (blastn only) [Integer] default = -3

-r => Reward for a nucleotide match (blastn only) [Integer] default = 1

What do I do if I only require hits with a maximum allowed mismatch or gap of 2 per alignment.


texts: Understanding the derivation of the Nernst equation

texts:
I am trying to understand how the Nernst equation can be derived and am mostly referring to the explanation given in the book Theoretical Neuroscience by Dayan and Abbott.

Given we have a concentration gradient and consider only Potassium, the overall approach to derive the Nernst equation is to find the equilibrium state where the flow of ions out of the cell and the flow of ions into the cell due to diffusion are the same. For the flow of ions we find the following two expressions:
$$
F_{out \rightarrow in} = \gamma [K^+]_{out} \\
F_{in \rightarrow out} = \gamma [K^+]_{in} \cdot exp({\frac{q V}{k_b T}})
$$
In these two formulas $\gamma$ is some complex factor that we don't know that e.g. encodes the number of channels but it does not matter since it will disappear when we equate both equations. $[K^+]_{out}$ is the concentration of potassium ions outside the cell and $[K^+]_{in}$ is the potassium concentration inside the cell. $V$ is the difference in electrical potential between the inside and the outside and $T$ is the temperature.

The reasoning given by Abbott and Dayan is that the flow of ions from inside the cell to the outside needs to overcome the energy barrier of the electrical gradient. Only ions that have sufficient thermal energy can do so, this is why the Boltzmann factor appears. The flow of ions from the outside to the inside does not need to overcome such a gradient. It is therefore proportional to the concentration of the outside.

The last part is where I struggle. Don't we need to account for the fact that positively charged ions are pulled into the cell due to the potential difference. Am I wrong in claiming that there is an electrical field that will increase the number of ions traveling into the cell?


texts:
There seems to be strong evidence to support the hypothesis that eating ginger helps reduce nausea e.g. during pregnancy (e.g. Vutyavanich et al.).  It seems that gingerol is the active ingredient in preventing nausea (cf. Qian et al.).  Wikipedia writes: "Cooking ginger transforms gingerol into zingerone...".  Presumably, zingerone does not affect nausea.

Question: Does cooking ginger reduce its anti-nausea effect?

A Google search will reveal numerous suggestions for giving ginger tea to pregnant women to help with morning sickness.  But boiling the ginger could conceivably defeat the purpose of taking the ginger in the first place (and any effects are primarily due to the placebo).

There's an article (Basirat et al.) which describes an experiment in which biscuits with ginger were given to patients (instead of ginger tablets), although their results alone have not convinced me one way or the other.  The authors conclude that their results indicate an anti-nausea effect, but some of their tests do not match that conclusion (i.e. a placebo was comparably effective).  Also, the group given the ginger biscuits started off with worse conditions on average.


texts: Do some cells have more than 2n at some part of their cell cycle?

texts: For example, do human cells reach 4n after s phase during interphase after replication of DNA?


texts:
This spring we have recieved from a local Botanical garden in Southern Germany a pack of seeds with the label "surprise". We could grow one plant from the seeds, the seeds looked like "pepper" = Paprika Capsicum annuum seeds. The plant got about 50 cm high and bore one fruit of 5 cm length including the trunk. The leaf in the picture has 10 cm total length. It has a very rough backside but not really hairy one. Also the upper side feels rough but there are no hairs. Also some yellow flower can be seen.

Initially I thought it is some capsicum so I cut it but was surprised when I saw the thick pulp. The skin is also quite strong and like very soft leather. It has a nice sweetish taste and some remembrance of lemon in taste but also some exotic "veggie" note. What could that plant be?

After searching the web my idea was that it could be Solanum sessiliflorum DUNAL, that is Amazonian tomato or "cocona". But I am not sure at all. Any hints appreciated!


texts: Can leukopenia in a person with an otherwise normal immune system lead to non-infectious diseases in the long-term?

texts:
If a person has developed leukopenia as a side-effect of long-term use of anti-convulsant medications and his/her immune system appears normal otherwise (does not get infections any more often than a healthy person, and bone marrow biopsy did not indicate anything abnormal), does the condition need to be treated? Is it even possible to treat leukopenia effectively as long as the person is on anti-convulsant medication?

Does leukopenia increase a person's chances of getting some non-infectious diseases too? I know WBC is primarily responsible for fighting infectious micro-organisms, but does it have any significant role in cleaning up body's own malfunctioning or ageing cells?


texts: What is the evolutionary advantage of regret?

texts:
Some motivational speakers may say that regrets are only useful to learn something from.

What are the other advantages?


texts: This is a dose-response experiment testing a new cancer drug.  the darker line represents cancer cells.  what range of dose should be used? I think it's 2-4 because this affects cancer cells only.  is this correct?


texts: Resources of all known biochemical pathways?

texts: I am looking for a encyclopedia or biochemical pathway atlas of all known or reported pathways. I am very much interested in network and systems biology. Also the references can be open databases, books or whatever. I came to know about a site called wikipathways , but it is not opening for me.


texts: Regarding detection of pregnancy during post mortem

texts: Is it possible to detect pregnancy in a woman who is dead considering the fact that she did not a have a showing belly.


texts: How to learn molecular biology through pubmed research articles?

texts:
Instead of using a textbook, is there an alternative curriculum, that simply lists a set of pubmed research articles for each topic covered in a typical undergrad molecular biology course?

I am currently learning molecular biology by reading a textbook.  Different chapters focus on different topics such as Cells and Genomes, Cell Chemistry, Proteins, DNA, Gene Expression, etc...  However, I'd prefer to learn these topics directly from research papers on pubmed.

For example, I would imagine the DNA "chapter" of such a curriculum would include the Watson Crick paper on DNA.

As another example, searching for "Protein" in pubmed reveals a ton of research papers, but which subset of them cover the topics taught in an intro molecular biology course?

Note: The pubmed articles don't have to be free or open access, I'm ok with getting the papers through my university library.  Also if an alternative curriculum such as this doesn't exist, maybe there is a supplemental one?  Or maybe you can recommend a set of papers that you'd include in such a curriculum?


texts: Why White Blood Cells (WBCs) do not react to foreign bodies like sperm?

texts:
Why do the white blood cells allow foreign bodies like sperm to exist inside body cavity without any reaction?

White blood cells function is to fight against foreign bodies (from the text books).


texts: Can you replace glucose with glycerol in cell media?

texts:
In order to feed an animal cell in process called Respiration, can I replace Glucose with Glycerol?

The Equation bellow:
Glycerol + Oxygen -> Water + Carbon Oxide


texts: What is a lip? (upper lip and lower lip)

texts:
Everyone knows what a lip is but I'm asking from a technical and anatomical standpoint.

Actually what we call "lip" is "vermilion" in medical terminology. But I want to ask if my understanding is right or not regarding to surface anatomy of the lip.

Lip consists of two parts called upper lip and lower lip. And upper lip and lower lip consists of two parts: skin (cutaneous) part and vermilion part  (vermilion is a special kind of skin also but we do not call it skin).

Thus:
Lip = upper lip (upper cutaneous lip + upper vermilion) + lower lip (lower cutaneous lip + lower vermilion)

This is a diagram that depicts the upper lip portion:

Source: http://elementsofmorphology.nih.gov/anatomy-oral.shtml

Questions:

Am I right so far? Did I miss any points?

Is the term "upper lip" ever used for the skin (cutaneous) part only? (especially in surgical terminology and reconstruction surgeries)

Are the "upper cutaneous lip" and "lower cutaneous lip" terms established terms in medicine? Are there any other names or latin names for those?  (I also see the usage of "cutaneous upper lip" and "cutaneous lower lip")


texts: Does every protein starts with Methionine amino acid

texts: During process of protein synthesis we need AUG Codon to start translation .As we know this codon codes for Methionine amino acid so can we say that every protein starts with Methionine amino acid ?


texts: I understand that evolution occurred to form the current hominids from a common ancestor millions of years ago. As evolutionary processes take a long time, is there proof of evolution occurring with humans today?


texts: Plants with nutritional requirements similar to Cannabis

texts:
What are some short plants that preferably could be grown indoor which have similar nutritional requirements (in terms of N-P-K ratio, doses etc.) as Cannabis?
The purpose of this is testing a mineral fertilizer for Cannabis, without actually growing Cannabis as it is illegal in my country.
I was looking into Cannabaceae family and found out that Hops are closely related. However, due to its size/height it won't be convenient to grow it at home. Also, I'm not sure if being in the same family implies similar nutritional needs.
Plus bonus for valuable/exotic plants.


texts: What is the expected effect of pH on the activity of a fungal pectinase?

texts:
I am working on an enzyme assay for a fungal pectinase.I assayed the enzyme in different buffers from pH 1-12.5 However,the enzyme has good activities starting from pH1-10.5.

Is it possible to have enzyme activity over such a broad range of pH?


texts: Molecular/cellular biology textbook to consolidate what I know about molecular/cell biology

texts:
I'm a medical student (who is halfway through med school) looking for a textbook that will consolidate some of the biology I already know. While I've read a lot of books that go into great detail about genetics, immunology and cell signaling, I've not found many books that focus on clear insights.

After recently having perused a very well-written nanotechnology book geared towards bionanotechnology ("Bionanotechnology: lessons from nature," by Goodsell), I found many cell biology topics very well explained. For example, it states simply that "lipids are used for infrastructure [in the body]", and that "polysaccharides are used in specialized structural roles". Such sentences I've personally never really come across in any of the "standard" molecular biology texts (Alberts, Cooper, etc); I found that they focus far too much on detailing exactly the components of the DNA polymerase, or the ribosome (which are very important, but also something I'd like to go "beyond".)

Clarification on what type of book I seek:

A book within cell or molecular biology
Scope of book; a book that covers any of the following: biochemistry, genetics (replication, translation, transcription, gene expression and its regulation, epigenetics, heredity, genetic engineering), developmental biology, cell biology (cell structure, organelles, cellular processes, cell signaling) and molecular biology (techniques such as high-throughput biology; concepts such as enhancers, repressors) and molecular evolution.
Level of the book doesn't matter, although I have completed all the subjects above at an undergraduate (bachelor) level - the book could thus be directed towards graduate/masters students.

Any books/texts that will hone one's knowledge on the subjects mentioned will be warmly received!


texts:
This is both a math and biology question but I think it makes more sense for a biologist to answer it. My question is: what can be said, if anything, about the space of all possible human DNAs (for a suitable definition of "human" in the context of this question)? Is it open or closed with respect to a suitable topology?

EDIT: To fix ideas and make it less a matter of opinion, one (admittedly incomplete, this is for the sake of making the question more precise) definition to use might be "those who can reproduce with existing fertile human beings"?

EDIT 2: To be clear, I am not a biologist but a computer scientist and maybe my question is guided by assumptions that simply do not hold. My naive vision of someone's DNA is a string of A,T,G,C which, when "interpreted", becomes that person. I am also under the impression that a single mutation of a letter may render them nonviable. On the other hand, other mutations may produce an individual with altered characteristics, who may or may not be able to reproduce with other human beings. So I was wondering if there is an interesting way to think of the space (in a mathematical sense) of all strings of DNA which produce a viable human being in this sense. If my assumption that a single mutation can render one nonviable, I would expect that this space would be "closed" for some topology.
I'm totally ready to accept that this way of thinking about DNA is flawed and/or unrealistic, and in that case I'd be happy to learn why, if possible in layman's terms.


texts: I read in Tortora and Derrickson that giving diuretics to diabetes insipidus patients may in fact alleviate the symptoms of the disease.  How is this possible?


texts: Is newly produced sperm healthy if there was previous DNA damage?

texts: I read that sperm cannot repair DNA damage. So does this mean that if your sperm has DNA damage, then all of your sperm (whether present or future) has DNA damage? Or does it just mean that the present sperm has DNA damage, but new sperm will be healthy?


texts:
I am learning myology and encountered 2 problems in tetanus and summation:

Unfused tetanus is just a continual summation of twitches if I am not mistaken. However, is it a MUST for summation / unfused tetanus to constantly increasing muscle tension from the photo (the graph) i.e. is this the definition?

Since we are in unfused tetanus when we hold something, and I can’t feel my biceps are constantly increasing in contraction / tension. (to my understanding, complete tetanus is when we are lifting up very heavy things only as it utilizes too much ATP)

Can I say the muscles are in tetanus during contracting (lifting), and also in tetanus during constantly contracted state (keep the thing holding up) Since tetanus is just a frequent action of sliding filaments, which is common in both actions?

Also, during tetanus, I don’t need to shorten my muscles anymore (just holding something still), but myosin heads are still power-stroking to shorten the sarcomere/muscle, may I ask how to explain this?
Thank you very much.


texts: We all know restriction enzymes are proteins, but we never freeze them. They are instead provided in high glycerol containing solutions by companies and stored at -20C. Is there a reason why this is so?


texts: Do cells communicate only in binary levels?

texts:
In modern communication we generally have various schemes to communicate the given signal, one of them is to convey information with different levels. does cell signaling too have levels apart from binary 'Yes' and 'No'.

For instance if a cell 'A' wants to communicate with another cell 'B'. I know it can do that by varying the concentration of molecules in the given media and 'B' will decide in favor of 'Yes' or 'No' based on the concentration sensed. But my question is does this sensing always happens in binary levels or is there some thing like:

If nothing sensed do operation 'a'
If moderate concentration sensed do operation 'b'
If high concentration sensed do operation 'c'

I mean communication not done in binary levels but may be quaternary levels. If yes can any reference be provided?


texts: What is the source of the electrons generated in the Krebs cycle?

texts: In the Krebs cycle, where do the hydrogens and electrons that NAD+ and FAD accept come from? It seems that citric acid only loses two hydrogens because it starts out with eight hydrogens and then becomes oxaloacetic acid, which has four hydrogens.


texts: What's the best sign language to teach a dolphin?

texts:
I know some scientists and trainers used hand signals to communicate with dolphins. The problem is: the dolphins have no hand to express themselves. With chimpanzees, we see how creative they are, not only in creating new words, but also in teaching their offspring without being told to do so (not sure if it was Jane Goodall who told that story in Through a Window).

So, what additional techniques could be used with cetaceans to really communicate with them?


texts: Interpreting SNP-in-gene associations from GWAS studies

texts:
For most SNPs identified in GWAS studies, is the underlying assumption that if it is indeed associated with a phenotype (and lets assume its associated because it affects protein function), that you don't need two knocked out copies of that gene for it to confer susceptibility risk to the individual?

In other words, is my assumption that GWAS is likely uncovering alleles that confer risk in single copy, correct?


texts: Examples of seeking behavior by brainless animals

texts: Are there any examples of brainless animals (e.g. jellyfish) exhibiting seeking behavior, such as following smell or light gradients towards food, or following hormones towards mates?


texts: Relation between bases while changing into a SNP

texts: Is there any relation or influence among the bases (A, C, G, T) while they are converted into a snp? Such as, is A converted into T, similar to converted into C or G? Or is this all random and no way to evaluate?


texts: How to convert a genus name to a noun or adjective

texts: Consider the crayfish family Cambaridae.  As I understand it, this familial name can be turned into an English noun or adjective by changing the first letter to lower case and dropping the "ae." An example use is "Responses of cambarid crayfish to predator odor" (adjective). Similar conversions from generic names are widely used as well.  For example, for the crayfish genus Procambarus, the english conversion "procambarid" is widely used, primarily as an adjective, but also as a noun. A google scholar search for this word turns up hundreds of uses.  A search for "id" conversions for other generics names for hermit crabs, and snake genera turn up uses of them as well. I cannot find any information that actually describes this conversion and it's rules.  Can someone point me to a reference, or otherwise help clarify the issue?


texts: Stomach Virus : How does it affect the bacteria of the intestines?

texts: When you have a stomach virus and it causes extreme bowel movements to the point of almost pure stomach acid, does this kill off the bacteria in our intestinal tracks?


texts: What value type would a chromosome position be in a database or form?

texts: I wanted to create a tool for some fields like SIFT, Phenotype, etc..so for example I know Phenotype will have "Text" values or SIFT will have some determined values from a drop down list...but what about Chrom Positions? what are some valid sample values for that? so I can know what type I can use for it.


texts: does phagocytosis dependent on opsonization?

texts:
does phagocytotic activity of macrophages and neutrophils depends on opsonization by IGg (antibody) and C3 complex,if it does, so then why macrophages and neutrophils are categorized in Innate immune defense system (despite the interference of antibody).

and if it is not dependent so why macrophages act as antigen presenting cells to make antibodies, while they lysed it and fragmented it (the pathogen) on it's surface by it's own,so what is the need for it to make antibodies while the innate system can handle it alone?


texts: How to fit simulated with measured data having systematic errors?

texts:
Consider a given time series of measured data, i.e. the number of persons tested positive for COVID-19. And consider a simulation - consisting of a model, possibly fed with some parameters estimated a priori (not via the measured data) - which gives another time series.

More often than not these two time series won't fit at once. But the goal of a simulation usually is to have a fit with measured data, and finally one wants to show: "See, these two histograms do match essentially."

That they don't match may have two reasons:

the measured data are erroneous (possibly in a systematic way) and/or
the model and/or the estimated parameters are erroneous

Assuming that the model is roughly correct (i.e. an advanced SEIR model) what are acceptable ways to "explain away" the gap between measured and simulated data?

The measured data may have two sources of error that are known in principle but not quantitatively:

a reporting delay (which includes incubation and latency time, time for testing, and time for proper reporting), giving rise to a shift of data.
a dark figure (i.e. cases that were not detected, falsely attributed, or false negative or positive cases), giving rise to typically lower values of the measured data (than in reality).

What is the "right way" to reflect these sources of errors, especially when drawing diagrams?

First correct and adjust the measured histogram, assuming some estimated reporting delays and dark figures, and then compare the corrected histogram with the simulated histogram?
First adjust the simulated data in a reciprocal way (by artificially adding some fictuous estimated reporting delay and dark figures) and then compare adjusted histogram with the non-corrected histogram of measured data?

Is one of these the one and only "good practice" - or are both or none of them scientifically tenable.


texts:
Doing a deck project and found a bird's nest.  Can I safely move it in order to continue working?

Think they'll fledge soon?
This is in New Jersey.


texts: Basic mathematical/logical reasoning makes it clear that you need two eyes to have depth of vision. By seeing an object from two perspectives, our brain can calculate the distance of the object based on the angle from each eye to the object. However even when I close one eye, I am able to judge reasonably well the depth of objects. Furthermore when I look at a picture I can instantly (I tried to be as unbiased as I could about this) tell it was a picture. How are we able to do this?


texts: Infection of urinary tract if the pH of urine is made alkaline

texts: It is very well known that drugs like phenobarbiton,morphine are unionized, lipid soluble.So,in case if there is toxicity due to these drugs,the only way to save the patient is make the pH of urine alkaline and thus facilitating its excretion.But,the normal pH of the urine is acidic which protects the person from various urinary tract infections,if the pH is made alkaline is there a increased for the patient to have urinary tract infections?


texts:
i was reading this artical after hearing about it on the news, while reading i saw the term "floaters" which made me remember of a recent Family Guy Episode in which there is a joke about them in Peter's vision.

I am wondering, what exactly are they? what is their technical term? and is it possible to remove them permanently (apart from the obvious gouging out your eyes).


texts: I see some source say octopus do not have sex chromosome. So what's the sex determination mechanism for cephalopods?


texts: How does the choice of blood draw site influence the possible specificity of a serological test?

texts:
The news has reported that a new serological test for the presence of anti-SARS-CoV-2 antibodies has received an emergency use authorization from the FDA, and notably has a higher specificity than other tests (99.8%).

The new test requires blood to be drawn from a vein, rather than a finger prick, and a quote from the test's manufacturer reads, "If you take blood from a finger prick, you will never be able to achieve the same level of specificity that you will achieve … when you take blood from the vein" (non-scientific news outlet source). Although the question is prompted by news related to COVID-19, I'm interested in the general case as well.

It is unclear to me why this would be the case, since antibodies should be present in capillary blood taken from the fingertip. I would suspect one of two reasons, but I don't have enough of a biology background to verify whether they make sense:

1) The volume of blood which can be drawn from a vein is much larger. This would make sense if it improved the sensitivity to a low-concentration antibody of interest, since there may not be enough antibodies in a fingertip sample to bind to antigens in the test. However, it's not clear why having a larger sample would help with specificity.

2) Fingertip blood samples are contaminated with lymph, matter from the skin surface, and so on. I'm not sure how it would affect the specificity of the test. In my naive understanding of serology tests, the reagent would consist of a synthetic antigen of interest, plus either anti-human-Ig or a second moonoclonal antibody for the antigen that would be used to detect any bound antibodies from the sample. It's not clear to me how these sorts of contamination could cause false positives for this sort of binding.


texts: Why the smell of sweat greatly varies across the body?

texts: Having only two types of sweat glands (eccrine, apocrine) I would expect the sweat odor "spectrum" to be very "narrow". However, the smell of sweat greatly varies between scalp, arms, armpits, groin and feet. Why is that?


texts: I've read that drinking river water is unsafe. Did people in the past drink water from the well exclusively or did they deal with diarrhea constantly?


texts: Insects or Birds covering least distance but most wing moves

texts:
I was in search in of list or detail about Insects and Birds which move their wings most but cover least distance.

I know that in insects house fly moves its wings about 200/sec and covers 5mph (about 7.3 feet) distance and in birds Hummingbird moves its wings about 80/sec and covers 60mph (about 88 feet) distance, but I am in search of about 10 in each insects and birds. And also about their heart beats.

If you have combine list, it will be much appreciated. If you know any book or website about same topic it will much helpful.


texts: How quicky does dental pH change after eating?

texts:
I would like to know how quickly after eating I can expect the pH do change in my mouth, and how quickly this will cause dental damage.

Obviously any answer to this will have plenty of caveats (diet, composition of oral bacteria, etc) but I would like some numbers for some scenarios please.


texts: Cancer: what does it mean "at presentation"?

texts:
Unclear to me what this means:

"Objective The biological heterogeneity of hepatocellular carcinoma (HCC) makes prognosis difficult. We translate the results of a genome-wide high-throughput analysis into a tool that accurately predicts at presentation tumour growth and survival of patients with HCC."

Reference


texts:
So for a project in one of my classes we must identify two monocots and two dicots growing at our school. We've managed to identify all but one:

So more information:

My school is in southern nevada
It's about one foot tall
It's growing with joshua trees and oak trees and some rosemary.

Update: I think it's a texas sage, but I'm not completely certain, verification would be nice.


texts:
My question concern the abbreviation of the genus of a species.

I talk about two species: Amphiprion clarkii and Amphiprion perideraion.

Question 1

Let's assume I haven't said a word about these species in my article yet. Should I say:

Amphiprion perideraion is a small fish and Amphiprion clarkii is a big fish

or

Amphiprion perideraion is a small fish and A. clarkii is a big fish

Question 2

If I talk about these two species in the abstract, should I use the abreviation the first time I cite them in the introduction or not?


texts: What is the biological age of grafted plants?

texts:
Suppose you graft a piece of an existing 'old' plant onto a host plant. Will the graft continue to grow having the same biological age as its parent? In other words, would the graft die at the same time as its parent plant? Or would the process of grafting result in some sort of rejuvenation of the grafted daughter plant? Or alternatively, would the host plant carrying the graft determine the biological age of the graft primarily?

PS: Personal experience-based (anecdotal) answers are more than welcomed


texts: Linkage is the tendency of genes on the same chromosome to remain together during the process of inheritance. Is it possible that two genes will remain linked generation after generation without any crossing over between them? Can anyone give an example?


texts: During a whole day breathing, how many kcal or watts do we get from the oxygen we breathe?