texts:
The 2019 study {1} reports that hip abductor tendon pathology is better visualized by 3.0 Tesla MRIs than by 1.5 Tesla MRIs.

The 2014 study {2} also mentions the usefulness of high teslas for tendon analysis:

  MRI of tendons and ligaments benefits from high spatial resolution. Stronger magnetic fields lead to higher signal-to-noise ratios and improvements in image resolution; for this reason, 3-T MRI may be more sensitive than 1.5 T for detection of partial thickness tears [26]. Alternatively, higher resolution may be achieved by using a local surface coil [27]. Imaging with shorter echo times improves sensitivity to tendon changes, although this may come at the expense of specificity [28,29]. T2 weighted images are helpful for identifying fluid signal in tendon or ligament tears (Figure 5) as well as for demonstrating changes in the surrounding tissues [30]. If the orientation of a tendon changes over its course, magic angle effects may be problematic; it may therefore be helpful to acquire images with a sufficiently long echo time to avoid these artefacts.

Which hardware specification should one be looking for to optimize the visualization of a tendinopathy through ultrasound?

References:

{1} Oehler, Nicola, Julia Kristin Ruby, André Strahl, Rainer Maas, Wolfgang Ruether, and Andreas Niemeier. "Hip abductor tendon pathology visualized by 1.5 versus 3. 0 Tesla MRIs." Archives of Orthopaedic and Trauma Surgery (2019): 1-9. https://www.ncbi.nlm.nih.gov/pubmed/31243547; https://doi.org/10.1007/s00402-019-03228-1
{2} Hodgson, R. J., P. J. O'Connor, and A. J. Grainger. "Tendon and ligament imaging." The British journal of radiology (2014).
Harvard ; https://scholar.google.com/scholar?cluster=16366672343955449638&hl=en&as_sdt=0,22 ;
http://www.birpublications.org/doi/full/10.1259/bjr/34786470


texts: Can restriction enzymes (Type II) displace single-stranded binding proteins (SSB)?

texts:
Many type II restriction enzymes have been shown to be able to cut ssDNA.
If single-stranded binding proteins are bound to single-stranded DNA (ssDNA), does this prevent restriction enzymes which cut ssDNA from scanning the ssDNA and interacting with the target cut site?
The NEB website says that using SSB's improve restriction enzyme digestion, so it doesn't seem to be the case that SSBs inhibit target site recognition. But it is unclear to me how a restriction enzyme could recognize the target sequence unless it can also displace SSB's while scanning.
edit: specified REs that cut ssDNA


texts: How can I control or anticipate the time that a caterpillar spends in its chrysalis?

texts:
My young daughter caught a caterpillar (pararge aegeria, to my non-expert eye) and we put it in a breathable jar with leaves, kept indoors in England. (Current climate is around 14-19 degrees Celcius at home, I have no specialist equipment to control the environment.)

In the last few days it has entered its pupil stage in a very dark brown chrysalis. I would like my daughter to be present at its emergence, if possible.

Is there anything I can do to either control the time that it emerges, or anticipate the time that it emerges?


texts: What parts of the brain are involved in regulating blood pressure in mammals?

texts: I'm reading this Wikipedia  article on blood pressure and its regulation, and it mentions that medulla is involved. however, I vaguely remember reading another article on Wikipedia and it mentioned that hypothalamus or hippocampus could be involved. So my question is - what other parts of the brain or neurotransmitters have significant effect on blood pressure regulation?


texts: What I can do in order to improve the folding of the protein?

texts:
I am struggling with the expression of the certain protein. It seems that it is not properly folded and thus, it is not active. I tried to express it at the lower temperature and for the longer time, but it did not help. Can anyone give me a clue what I can try to do?

The size of the protein is around 55 kDa. I know that I have some soluble protein as I run western blot. The protein contain His-taq on the C-terminus so I started with Ni-NTA column chromatography. Steps of purification:

Incubation the lysate with resin (30 min/4°C)
Unbound proteins were collected as the ‘Flow-through’ fraction
Wash 1 with buffer: 50 mM NaH2PO4, 1M NaCl, 10 mM Imidazole
Wash 2 with 10% buffer B in buffer A
Elution with buffer B: 50 mM NaH2PO4, 1M NaCl, 250 mM Imidazole

Because the protein is co-purified with something else in size around 57 kDa (which might be a chaperone protein) I tried also:
1. add ATP to first wash in concentartion of 2.5 mM and incubate column for 1h/4C
2. add ATP to first wash in concentartion of 2.5 mM and incubate column overnight in 4C
3. add ATP to first wash in concentartion of 2.5 mM and incubate column overnight in room temperature
4. add ATP and glycerol to first wash in concentartion of 2.5 mM for ATP and  4M for glycerol and incubate column for 2h in 4add ATP to first wash in concentartion of 2.5 mM and incubate column overnight in 4C

All the method end up with two close to each other bands (only one of them is my protein) and protein is not active.


texts: First of all, a fish opens its mouth and water enters which passes through its gills. This helps in oxygenating its blood. So, if any food particle is in its mouth, how can it "breathe" i.e. how does exchange of gases occur? Shouldn't the pathway where water flows from mouth to gills be clogged like a drain full of sludge?


texts: Does a cell suspend or exit cell cycle at G0?

texts:
In an exam, there was one question which asked whether the cell exits or suspends cell cycle at G0 phase.

I answered that it exits cell cycle but the official answer key says it suspends cell cycle.

I marked exit because a cell in G0  undergoes differentiation and maturation. Is there a difference between the two terms?


texts:
I saw this fascinating article today about how HIV moves through a mouse host in real time.

http://www.engadget.com/2015/10/02/watch-hiv-spread-through-mouse-in-real-time/#continued

It's common to hear a virus' activity described in the way the article does: with intent.

I have a hard time understanding this. Something is considered alive when it has a metabolism, takes in nutrients and expels waist.  It has to have some kind of respiratory system and it's own reproductive mechanism. Although locomotion is optional, most forms of life have some form of getting around.  Some plants are able to move somehow...

Viruses have no sensing organs and no method of locomotion.  They cannot smell or see or move on their own.  This means they have to be carried inside a cell or if free floating in a host's fluids, rely on random motions to get about.

In order to invade, as far as I understand this; they must essentially wait until they come into physical contact with a compatible target.  At this point, their protrusions (I call them "keys") attach to a host cells "door" and they then inject their DNA.

Most (or all?) cells use Mitochondria for "power" so they can do things - like metabolize and reproduce.  I've never seen a diagram of a virus that shows where it get's it's energy to power the 'injection' part of it's 'life cycle'.

How is this done?

In the mouse video, the HIV virus looks like it has a "plan" and that it knows how to select which initial cells to invade and then how to pick a good method of remaining hidden.  How can this be when they have no sense organs?  How can they "know" of other virus particles are being successfully attacked by the host?

This is incredible and incredibly complex.

I'm not a medical professional. I'm just a fascinated by-stander.


texts: Do non-green flower colors have any functional interactions with the sun?

texts:
I always hear the pseudo-evolutionary claim "plants are green because they need to use red and blue light".  If this premise to my question is true,

What (if any) other functional relationship occur between the color of the blossom of the flower or the color of the leaves in the fall, and the spectrum of the sun.  Could it be said that plants are actively absorbing a particular spectrum for a particular purpose by expressing particular colors other than green?


texts: Gene of interest number of copies in transformed K. pastoris

texts:
When transforming a K. pastoris strain, is there a way to predict how many copies of the gene will be integrated following the homologous recombination? More specifically is it something that a molecular biologist is able to control in a simple way, or, is it usually left to the chance (and determined afterward using gene sequencing)?
Alternatively : if I want to transform an electrocompetent wild type strain such as Pichia X33 using a plasmid vector, is the multiple integration an iterative process I control or is it random?)

Edit: Thank you all for the answers. Finally if I understand well the process is pretty random but you can control it to some extent. @gaspanic: I keep the idea of using fluorescent reporters and FACS for that ;)


texts: Was Earth's atmosphere more buoyant in the prehistoric era then today?

texts: The mass and size of the dinosaurs and prehistoric insects continues to amaze me. I read from an earlier post that oxygen was more abundant during the prehistoric era. However supporting the weight for me is still a mystery. Is it possible that the air was denser, allowing slight decrease in weight from greater buoyancy?


texts: Is there any evidence of causation for breathing rate to affect blood pressure in a human?

texts:
I did some research and trials, and with 5 trials for a normal heart rate and 5 done 45 seconds into breath holding, the results came back showing that my heart rate of 116/65 mmHg increased to 138/90 mmHg. I was interested in the cause of this, but couldn’t seem to find any evidence online to explain why this happens, exepct for some simple studies that showed that their is a correlation.

So my question is: has there’s been any studies that hypothesize or found a reason for breath holding to affect blood pressure?


texts:
Assume we know the right DNA sequence of Mycoplasma Genitalium (MG) and we would like to create Life from scratch.
Also assume that matter has been created and we have the knowledge base as today.

How could we practically or theoretically take such a sequence and create a new MG?

I saw this in case you want to read more:

https://www.quantamagazine.org/first-support-for-a-physics-theory-of-life-20170726/


texts: Regarding different nucleotides on a DNA strand

texts:
I am not a biologist therefore, it might seem as an elementary question. I retrieved rodent sequences from UTR database:

http://utrdb.ba.itb.cnr.it

And I know there are supposed to be four nucleotides namely: A,G,C, and T. However, on this database I get sequences that have 'n' nucleotide in several locations, 'm' and 'k' as well. What does these letters mean? I haven't been able to find anything regarding it. Does it mean these positions in UTR are undefined or they are some 'intermediate' nucleotides if there are any?


texts: Is gene only the portion of a single strand which codes for a particular protein?

texts:
I know that gene is a segment of DNA that codes for a specific protein. But is it a segment of a single DNA molecule or a DNA duplex?

The given image shows a section of a dsDNA.

Source of image:https://en.wikipedia.org/wiki/Intron#/media/File:Gene.png

Suppose its the blue portion (5' to 3') that codes for a particular protein.
The figure tells that the blue portion + its complementary red portion make a gene. But if its the blue portion which actually codes for the protein, then shouldn't it alone be considered the gene for that particular protein ?

i.e. Why are portions of the both the DNA strands considered a gene in the figure?

Trust me, every picture on the internet tells the same.


texts:
When I was a kid and someone got a concussion, I seem to remember people telling me that it was when your brain impacts the side of your skull, accelerating fast enough to do so despite the cerebrospinal fluid buffer.

But wikipedia doesn't mention this explicitly. Is this just one possible cause for concussions? Is it possible to generalize about them? How much don't we know?


texts: Monozygotic vs Dizygotic heteropaternal superfecundation

texts:
Update: I had a wrong assumption.

After triple checking, I now see that how ordinary monozygotic twins arise is 1 sperm and 1 ovum and then later the zygote splits up.

(1.1. and that that phil and lil from rugrats are opposite sex and identical twins is actually an extremely underrated genetic miracle, possibly giving more credibility to the rugrats theory/hypothesis. There's also semi-identical twins in a song of ice and fire - though i guess not game of thrones -, Ben 10, legend of korra, KND, baka to test, and i think samurai jack, etc)

Honest to God, what i weirdly remembered was that ordinary 'monozygotic' twins arise from 2 sperm 1 ovum and then this 'zygote' or whatever of 2 sperm and 1 ovum splits up into 2 zygotes i.e. the splitting up of the 'zygote' is a natural consequence from that 2 sperm have fertilised 1 ovum. From what I weirdly remembered, it would be natural to ask what if the 2 sperm were from different males.

(2.1. Additionally, the Phil and Lil thingy is not really a genetic miracle since all you need is a 22X sperm and a 22Y sperm to fertilise 1 ovum. Damn television. i really thought opposite sex identical twins were not that rare.)

However, apparently it is possible for 2 more sperm to fertilise 1 ovum, in a case called semi-identical twins or something, but there are apparently only 2 reported cases.

New question: Okay in the unlikely event that what would be semi-identical twins would arise from sperm from different males, well, then what?

From wiki:

Homopaternal superfecundation refers to the fertilization of two separate ova from the same father, leading to fraternal twins;6 while heteropaternal superfecundation is referred to as a form of atypical twinning where, genetically, the twins are half siblings.

There doesn't seem to be a distinction between heteropaternal superfecundation occurring with two ova and with one ovum. How will monozygotic heteropaternal superfecundation twins look like as opposed to dizygotic heteropaternal superfecundation twins and to identical twins?

Are/Were there real life cases of monozygotic heteropaternal superfecundation?

The heteropaternal superfecundation selected cases given on wikipedia seem to be for dizygotic. I tried looking up on google, but I've found so far only dizygotic.


texts: What exact characters determine an animal's Genus?

texts:
I do know that if two animals cannot naturally reproduce, they are said to be of two different species. But what determines the genus?

Just for example, the African elephant belongs Loxodonta but the Indian counterpart belongs to Elephas , despite the fact that they are so similar, as opposed to say, the fact that, the Bengal Tiger and the Snow leopard despite being so different , are placed in one genus, Panthera ?


texts: Are there any air-plants with parts that are edible for humans?

texts: Are any air plants (Tillansia sp.) safe for humans to eat? I haven't been able to find whether or not there are. Pineapple is in the same family (Bromeliaceae), but isn't an air plant.


texts: Book recommendation to know and understand the brain and the phenomena and processes related to it

texts: I need a book recommendation or, more properly, any source recommendation to know and understand more about the phenomena related to the brain, as far as we know how the brain works. I'm interested in the very structure the brain has and how it leads to what we experience. Due to the way biological processes happen, how the things we define for ourselves are related to each other. It would be cool if it adds more to the biophysics of those processes and the possible picture of their evolution, as well as the physical characteristics of those biological structures.


texts:
Ten of these bugs were found behind my bed. I live in Northern California.
The bug is 5mm in length.


texts: In my biology textbook, I read that the primary oocyte gets arrested in the early stages of meiosis in prophase I (diplotene stage). I wanted to know why this is so. I searched google, and this phenomenon is known as dictyate. Furthermore the source was talking about translational arrest after transcription. Why does it occur during cell division? Moreover, what's so necessary about this phenomenon?


texts:
I have been asked whether hormones are antigenic.

I would have to think that the answer is no because they are used as various drugs such as FSH in infertility treatments without the need of immunosupressants.


texts: More efficient method of calculation genotype or phenotype ratios rather than doing a trihybrid punnett square or forked-line method?

texts: Is there any other more efficient method of predicting ratios of offspring phenotypes or genotypes than doing a trihybrid Punnett square or forked-line diagram? Or are those two methods really the only solution. This is for a question dealing with unlinked traits.


texts: Why are there species instead of a continuum of various animals?

texts:
As I understand it, various animal traits have to evolve gradually, but what happens to the species that are "neither here nor there"?

To put it differently, if a species evolved from another, it did so because it's somehow better, right? So why are there examples of the original species not being extinct?

What factors determine weather some species "stick"?


texts: Role of epigenetics in evolution and transmission of defects caused by drugs

texts:
In a documentary, they were saying that epigenetics changes caused by the environment in an individual can be transferred to the following generations. I have some questions on that:

How many generations are affected by an epigenetic change? can this be permanent?

Can drugs cause epigenetics changes in the current population that are visible in the following generations in the form of disease and birth defects?

Do epigenetic play any role in evolution? For example, is it possible that an epigenetic change becomes a permanent genetic change after a certain number of generations?


texts:
For my course project, I am thinking of listing out major chemical reactions that occur at synapses, along with their temporal characteristics.

I could not find any textbooks to use as a starting point, and Google did not help me either. I was hoping to receive help in finding a review paper or textbook about chemical computations at the synapse.


texts:
I read the Wikipedia article on acute flaccid myelitis which contains a graph showing confirmed US cases peaking biennially in 2014, 2016 and 2018.

That got me wondering because I found that pattern to seem unusual compared to an annual one tied to seasons or a constant or increasing one. So I did a quick Google search on "biennial patterns in rates of infection" and turned up this paper: Regular biennial cycles in epidemics caused by parametric resonance which discusses, mathematically, the biennial patterns sometimes found in the incidence of measles.

What I'd like to know, in layman's terms, is the causes of biennial patterns such as these in terms of the way these infections spread among victims and develop within them.


texts: Factor causing Methicilin-resistance in MRSA?

texts:
I think the main reason is the natural selection that is causing methicillin-resistance.
However, I am not completely sure what this means practically.

Here, the original question:

MRSA was isolated in the throat secretion of patient hospitalized with bronchitis. Which of the following
statements best characterizes this microorganism?

a. its MIC is increased to methicillin, but not to penicillin
b. methicillin-resistance is associated with production of β-lactamases
c. Methicillin-resistance is caused by changes in configuration (mutation) of PBP

What is the right answer?


texts: Is the DNA different in each type of cell? What DNA is passed to offspring?

texts:
Our body contains many different types of cells and each of those cells have their own DNA (correct me if wrong) like skin cells their own DNA that makes them skin cells instead of muscle cells.

So my question is what DNA does a human pass down in a sperm or egg cell? Is it a specialised DNA imprint from which our whole body can be created?


texts: Has there ever been an attempt to create nutritionally tailored food for adult human consumption?

texts:
For all domestic animals, and for all animals kept in laboratory, complete and precise composition of perfect food is figured out (cat food, dog food, cattle, rats, laboratory monkeys and apes) -- which contains precise composition of carbs, fats, proteins, aminoacids, minerals and vitamins. Everything is known. Convenient dry cat/dog food contains exactly that. Animals are healthy on this food.

The composition is also known for human babies. This is manufactured as "baby formula". Everything baby's organism needs to be healthy (and to grow).

How let's take human adults.

Was ever attempt made to create "dry human 'dog-food'"? This sounds stupid, but there are emergency situation in which such food can come very useful.

So my question is, is there anything special in human biology that prevents creation of complete "dry human food" that contains everything our organism needs to be healthy ?

Or it was created but tasted so disgusting that nobody would eat it ?

Or it actually exist somewhere ? Just curious.


texts: How to search for a protein sequence of an specific taxa in NCBI?

texts:
My example: Sequence of HBB (Hemoglobin Beta) in Fishes.

How can I do a good search to obtain above sequences in NCBI? (I know hot to download them into a FASTA file)


texts: Why is leucine amino acid used the most in proteins and tryptophan the least?

texts:
The amino acid leucine, is used in proteins more than others. Leucine with 9.1 percent (its average in more than 1.150 different proteins) is used most and tryptophan with 1.4 percent is used less than all other amino acids.

Why is leucine used more than tryptophan?


texts: Can a new plant grow from half a Succulent leaf?

texts:
Succulents like Crassula ovata can be propagated by simply tearing a leaf from the stem and putting it into soil. The leaf will usually grow roots and additional leaves from the calloused wound, and eventually become a full Crassula plant itself.

Now I only have half of a leaf left, the other half got rotten, and dried out. In particular, the part of the leaf that was attached to the mother plant is missing. The remainder is about 3/4" long.

Is it still possible to grow a new plant from just this part of a leaf? Or is it at least necessary that the part of the leaf that was attached to the stem is still present?


texts: Reference request: neocortex creating 11 dimensional structures

texts: I've come across several pop science articles like this one that vaguely describe a method of analyzing brain tissue involving algebraic topology and 11 dimensional structures. They all seem to cite each other. One of the researchers involved was Kathryn Hess. I've searched the web, a community college library, and the UCLA library and haven't been able to find the original paper. Does anyone know where I could learn more about their methods?


texts:
I have an annotation from gencode.vM1.annotation of a mouse. Exons, genes, transcripts and UTR are listed there. For each feature a start and end positions are present.

I need to find a TSS for each gene. Will it be wrong to define one TSS for all transcripts belonging to one gene? So, I want to define a TSS for each gene as a minimum start UTR from all transcripts.

Example:

gene id, transcript id, feature, start, end

gene A, transcript A1, UTR, 102, 205
gene A, transcript A1, UTR, 506, 520
gene A, transcript A2, UTR, 78, 205
gene A, transcript A2, UTR, 502, 512

So, for gene A I would define a TSS on position 78 (minimum start UTR). And the gene body end on the position 520 (maximum end UTR).


texts:
I know, this question is opinion-based, but where else should I ask it (or how could I ask it here without being flagged "opinon-based!")?

Which neuronal simulators - in the line of NEURON and GENESIS - are the "best", "mostly used", "mostly influential" today, not only in supercomputing, but also for small scale (personal) use?

The one I found best - even though designed for large scale applications - for my small scale (personal) requirements was nest, an explicit successor of NEURON. I have the impression, that nest is "better" for me than NEURON, in terms of usability, visualization, data exploration, ... but I don't know if there aren't even better neuro-simulation tools.

Would anyone mind giving his/her opinion?


texts: Does the Valsalva maneuver require a completely closed airway? How do the effects compare to exhalation against partial resistance?

texts:
The Valsalva maneuver is defined as "attempted exhalation against a closed airway", "The effort to breathe out forcibly while the mouth and nose are firmly closed or the vocal cords pressed together", or, colloquially, straining as if you were trying to poop. It can "pop" the eustachian tubes open, stimulate the vagus nerve, and briefly spike blood pressure, occasionally leading to people dying from a burst aneurysm on the toilet.

Some breathing practices involve pushing air out against resistance, such as ujjayi breath in yoga. This can be done by partly closing the glottis while exhaling, or by firmly exhaling through the mouth with lips slightly open, as if one were whistling. It can also happen while forcefully exhaling through a congested nose.

This seems like it should raise eustachian and thoracic pressure in the same way as the "full" Valsalva maneuver, though to a lesser extent. Are the effects of these other breathing practices similar to the Valsalva maneuver, or are there any unique effects of the Valsalva maneuver that only occur with a fully closed airway?

As a second question, would you expect any unique effects exhaling against resistance? It seems different in that the practitioner is still breathing, and that they can continue the practice indefinitely, as opposed to a breath-holding Valsalva.


texts: How does DNA codon (5`-3`) convert to mRNA?

texts:
There is a problem I stumbled upon when doing a lesson on molecular genetics (Grade 12 level).

The lesson contains many tables in this format:

I don't understand how it got to the mRNA codon considering how RNA polymerase creates mRNA. From what I know already RNA polymerase reads the anti-sense/template strand (3`-5`strand) and synthesizes mRNA in a 5`-3` direction.

For example, using the first column with the DNA codon 5`-TAC-3`, I would automatically convert it to 3`-5` complementary anti-sense strand because of the nature of the enzyme. It would be 3`-ATG-5`. Now using that anti-sense strand I would find the complementary base pairs and the mRNA strand would be 5'-UAC-3'. This is not consistent with the example given by the lesson. I can understand how to get to the answer (just find the complimentary base pairs of the DNA codon given) but it goes against what I know.

Now if the table said (3`-5`) instead of (5`-3`) it would make sense. Am I misunderstanding a fundamental concept?


texts: Do male marsupials have a pouch, or is it a female organ only (like the womb)?


texts: What is the mechanism responsible for the periodicity of hiccups?

texts:
Hiccups (singultus) are caused by involuntary spasm of the intercostal muscles and diaphragm, producing a sudden inspiration with associated glottic closure. It seems the neurobiology of the reflex has been relatively well worked out (nicely summarized in this review):

Afferent limb: the vagus, phrenic, and cervical sympathetic chain
Central mediators: the hypothalamus, medullary reticular formation, and brainstem respiratory centers
Efferent limb:  primarily mediated by the phrenic nerve but also including the intercostals, and secondarily the recurrent laryngeal nerve to cause glottic closure

To my knowledge, hiccups are always cyclical, with a period of between 1 and 30 seconds. According to the afore cited article, this interval is relatively constant it a given individual. The cycling stops after some time; efferent vagal tone can suppress it, or it stops spontaneously. My question is:

What is the mechanism responsible for this periodicity?

Something must be triggering that afferent limb every 1 - 30s, but I can’t think of a normal physiologic process that triggers the firing of one or more nerves with such periodicity and then stops abruptly.


texts: Finding numbers for the amount of neurons in the brain is quite easy. Finding them for other human organs is harder. How many neurons are there in the human heart?


texts: There are 6 classifications of CFTR mutations. Is a causal relationship to the sweat test known?

texts:
Cystic fibrosis (CF) is caused by mutations in the gene for the protein cystic fibrosis transmembrane conductance regulator (CFTR).

The CFTR mutations are classified in 6 classes.

The sweat test is used to screen for CF. With the following boundaries:

<= 29 mmol/L = CF is very unlikely
30 – 59 mmol/L = intermediate possibility
=> 60 mmol/L = CF is likely

Can I make assumptions from the sweat test in which category a patient may belong? Or can I even make assumptions about a specific mutation?


texts:
According to Campbell Biology,

  A growth factor is a protein released by certain cells that stimulates other cells to divide.

and according to Wikipedia,

  A mitogen is a chemical substance that encourages a cell to commence cell division, triggering mitosis.

What’s the difference between them? I suppose a mitogen specifically refers to mitosis, but if something is stimulating mitosis, isn’t it stimulating growth? Are mitogens all growth factors? Are all growth factors mitogens?


texts: What is the rest state for eyelids - Open or Closed?

texts:
If one were to not apply any efforts on the eyelid muscles, will they remain open or closed?

In movies when we see a person die, either case could happen - their eyelids could be open or closed when they pass away. (Not sure if that's the case in real life, as I have been fortunate enough to not witness any deaths).

I started thinking about this when I got into meditation. During meditation one is supposed to relax all their body muscles. I wonder, if I were to reach that perfect stage of relaxing what will happen to my eyelids. Will they automatically open? I feel like I've to make tiny yet finite deliberate effort to keep them closed. Not sure if that's the case with everyone.


texts: What are the small lumps in the mouth of the fish, and what is its function?

texts: Today I was performing a fish head dissection to investigate the gas exchange process in biology. Then when I opened the mouth I noticed these small hard structures at the base, I assume they may be a form of teeth that allows the fish to grind hard shells of invertebrates and plant matter. Yet I was curious as to why some fish have this and others don't and what exactly it's function is. Also if you have a name I would highly appreciate it as I can label it in my lab book. Thank you so much for your time.


texts: How is yellow elastic cartilage a true cartilage?

texts: My book has only mentioned the fact but no reason is given so I would like to know the reason for it. I would like to know what more to add in the body but the question just doesn't get posted.


texts: How long does it take for a blocked dopamine receptor to be broken down by the body?

texts:
Do the blocked dopamine receptors get broken down by the body and if so how often ?

In other words how long does it take for the dopamine receptors blocked by irreversible dopamine antagonists to degrade ?


texts:
Dosage compensation is used to make up for different copy numbers of the major sex chromosomes in males and females (One X or Z chromosome in one and two in the other). Two main mechanisms of dosage compensation exist, inactivation and upregulation.

But dosage compensation is not entirely perfect, the amount of gene product from an upregulated X/Z-linked genes in the heterogametic sex is not exactly that of the two in the homogametic sex.

  "In Drosophila, the male-specific lethal (MSL) ribonucleoprotein
  complex mediates dosage compensation by upregulating transcription
  from the single male X chromosome approximately twofold."

On average how well is dosage compensation performed? What is the variance like:

within a single chromosome (between genes)?
within species?
between species?


texts: Why are lips covered with specialized skin?

texts:
I found out some interesting facts while studying our lips:

They are covered in glabrous skin, while most of the skin surface is hairy;
The outermost layer (stratum corneum) of the skin is far thinner than on any other part of our body;
They lack pigmentation (melanin);
Their pink colour is due to underlying capillaries.
Their only source of moisture is our saliva. They lack sebaceous gland;

  What is the reason behind this specialization of our lips?

Why is it not covered with the thicker skin type found elsewhere on the body? The lips are not more sensitive than the fingertips for example (see figures below), i.e., the pressure thresholds are similar (upper graph) and the two-point discrimination thresholds as well (lower graph).

Source: Dreamviews

Source: Institute Balseiro


texts: Are the number of base pairs in a given chromosome same between different individuals?

texts:
This is a basic question but I couldn't find an answer through a web search; hopefully this is the right place to ask. Is the number of base pairs in a
particular chromosome the same in all individuals? For example if I take an
X-chromosome from two random humans would I count exactly 155,270,560
base pairs in both cases? or are there mutations that would make one longer than the other? If they're not exactly the same, what's the range in length variation?


texts: Why doesn't pure fat taste better than pure sugar?

texts:
I mean looking from evolutionary perspective sugar tastes sweet and individuals that had this perception ate more sugar and survived and those that didn't perceive sugar as sweet didn't eat it and died from hunger.

So the better (more caloric) food is - the better it should taste so that one would be more likely to eat it and if choice had to be made between berries or lard (assuming that food is scarce) one should go for lard as this would increase his chances of survival

Out of all foods lard has the highest calorie content (898 cal per 100g) and therefore highest concentration of fat and yet it doesn't taste very nice.

There must be some explanation why fat doesn't taste much better than sugar?


texts: It's my understanding that most human sensory systems obey an approximately logarithmic stimulus/response curve. This includes the visual system, auditory system, and the smallest perceptible difference on things like weight. Do we know the origin of this pattern? Is it something inherent in how neurons encode information and fire (for example, maybe the refractory period reduces neuron responsiveness to stimulus in just the right way relative to how information is encoded)? Or is it something that specifically evolved to give us the ability to handle a wide range of stimulus amplitudes? If it's the latter, how is the transformation from linear stimulus/response to logarithmic response achieved?


texts: Why doesn't it feel suffocating when taking a shower?

texts:
When one walks into a bathroom where someone is (or just finished) taking a shower it is hard to breathe, because it's filled with steam, yet the person taking a shower can breathe just fine despite being in the area with even more steam.

Why is that?


texts: What mechanism suppresses melatonin release in humans?

texts: I'm looking at melanopsin, a photo pigment in the human eye. One of its actions is to trigger suprachiasmatic nuclei SCN to suppress melatonin release. I'm interested in learning what is the exact mechanism that actually suppresses melatonin release. Is it another hormone or some way of modulating the pineal gland function?


texts: Why is the Kakapo more attracted to humans than its own kind?

texts: The Kakapo can be seen in this video by BBC. It is said that the species is strongly sexually attracted to humans. Why could this be the case?


texts: Distinction between primary and secondary tumor

texts: How can a primary tumor be distinguished from a secondary tumor? I tried finding it on the internet but it only said that they are found by means of immunohistology but I couldn't understand how.Please elaborate


texts: How are behaviors genetically coded in animals?

texts: I am curious as to how complex behavior is passed down genetically? For example, how is the building of a web genetically coded in a spider? And how is the complex behavior of constricting prey coded into a boa? As these critters do not get raised by their parents, and hence cannot learn to copy these behaviors, it has to be genetically imprinted. How?


texts: Is consuming proteins different vs. consuming amino-acids and how?

texts: Yesterday I had a discussion with a friend. He said that consuming proteins and amino-acids is different. He said that those who grow muscles would agree on that. I wanted to argue against that statement, but I lacked arguments... As far as I know, amino-acids are part of proteins. So, when proteins go to our body with food, we digest it and make amino-acids. Then they can form any kind of proteins we need. The same would happen when consuming amino-acids directly, not in protein form. Maybe then the process would be faster. But from my point of view, there is no much of a difference. Could anyone please give me a more sound opinion on why is consuming proteins and amino-acids different, if it is?


texts: Is epilepsy genetically inheritable? If yes, is it dominant?


texts:
There's a flying insect being caught indoors today in Sydney Australia. Before it is being caught, it basically flies like a moth. However googling of Tinea pellionella and other cloth moths does not suggest it is a cloth moth as hair is missing from its very small sized head.

It is also known to be very common every year when spring approaches in australia

To assist identification, the bug was caught in a plastic jar to allow multiple angles of it to be photographed

Measured body length (not including long antennae): 1.1 cm
Color: Brown an golden brown with lustre
Legs: 6 (front pair very short, middle pair is forked, hind legs have some golden brown feathery structure)
Head is black, very small and have no hair

Here one can easily see the hindlegs are covered by some bristle like golden brown feathery structures, and also its shiny golden segmented abdomen

The camera is not fast enough to capture it unblur when it is flying, but the few moments when it opened its wings can be seen here extracted from a video

And these are our best shots using the iphone camera in capturing its flight with its wings fully opened.

  Is this a type of moth, is it a pest or is it neutral. What is the species?


texts:
I found this insect in Fish Haven, Idaho (right next to Bear Lake) in June and think it’s absolutely fascinating:

If you can’t tell from the picture, it’s a few centimeters in length—very thin with a pair of transparent wings that extend straight backwards past the end of the abdomen. The thorax is brown, and past the point where the wings connect it is long and neck-like, leading to a black head with two long antennae. Can anyone identify this insect?


texts: What metabolic processes do dormant and ungerminated seeds carry out?

texts:
What metabolic processes does a dormant embryo in a seed carry out?

Seeds will not germinate, either because of a lack of favourable conditions, seed hibernation, or because of a genetically pre-determined physical or physiological mechanism preventing germination before a specific period or event. In addition to not germinating due to those factors, seeds can also experience dormancy.

With these germination preventing mechanisms in place, the seed will not germinate in the absence of specific triggers. But the seed viability period is limited in which it germinates if the trigger is available.

If any, what metabolic processes do seeds carry out in their dormant/hibernating state, on cessation of which, the seed becomes non-viable?

  Does the embryo in a dessicated dormant seed respire, excrete, ingest etc, though with a reduced speed? If it does, is the depletion
  of the respiratory substrate which results in termination of seed
  viability?


texts: Hela cells are infected with HPV. So is it safe to work with them? What are the safety precautions?


texts: Is there a word for the assumption that a sufficiently complex and refined organ must be the result of natural selection on a large time scale?

texts:
Is there a term for the valid assumption that a sufficiently complex and refined organ must be the result of natural selection on a large time scale?

Example:
A biologist exists in a world where nothing has eyes.  They find a creature with an eye as developed as a modern mammal's in our reality.  Assuming this biologist understood what the eye was able to do as far as limiting and focusing incoming light and sending visual information to the brain, etc - it would go without saying that this was a gradually evolved system.

It would be impossible for a parent from a completely eyeless ancestry to spawn a child that had the equivalent of a fully developed modern mammalian eye, both because of the statistically improbability of that happening, and possibly even because of limitations in the way dna works.

Is there a word for this assumption? e.g. "As per the Axiom of Reliable Intuitive Ancestry Determination for Sufficiently Complex and Refined Traits, we will start our genetic research confident that the eye must be the result of iterative natural selection on a large scale of time."

Preferably a term that acknowledges the validity or reliability of this assumption when it comes to very complex and refined organs or systems, such as the eye, the brain, or the circulatory system.


texts:
RNA is known to form an A-form helix, while DNA generally forms a B-form helix under physiological conditions.

From left to right: A-form DNA, B-form DNA, Z-form DNA. Image created by Richard Wheeler

The preference of RNA for the different conformation is supposed to be caused by the 2'-OH, my question is now how exactly this favors the A-helix? Which interactions are important and cause RNA to adopt an A-form helix?


texts: Bacterial cell lysis buffer used in proteomics procedures

texts: What kinds of detergent-free bacterial lysis buffers exist? The proteins we're extracting will be later analyzed by LC-MS/MS, and we're looking for a lysis buffer that won't interfere with this downstream analysis.


texts: Recombination between DNA segments question

texts:
In the diagram shown above, segments A and C are copies of a repeated DNA sequence, flanking a unique stretch shown as B. A and C are in an inverted orientation relative to each other, as indicated by the arrows. Intramolecular recombination between segments A and C would most likely lead to ...

duplication of segment B only
duplications of segments A, B, and C
inversion of segment B
deletion of segment B only
deletion of segments A, B, and C

I do not understand this question. Or how the answer was arrived it. Can someone provide some light on the subject? Is this related to transposons?


texts: What does it mean to "cure" microscope slides?

texts:
I am reading a journal paper and I have come across the following statement in the materials and methods section regarding the preparation of microscope slides:

Coverslips were washed once more with PBS, inversely mounted on
microscope slides with ProLongTM Diamond antifade mountant containing
DAPI (Invitrogen). Slides were cured for 24 hours at room temperature
before observation.

I am not sure what exactly is meant by the statement the "slides were cured". I have searched on Google for some answers but I have not found anything useful. Any insights are appreciated.


texts:
Dune (novel) describes a body suit called Stillsuit:

  a stillsuit is a "body-enclosing garment" of Fremen design which
  performs the "functions of heat dissipation and filtering bodily
  wastes", as well as retaining and reclaiming moisture

For this question, I am interested into reclaiming property of this suit. The book argues about the fact that the losses were virtually only due to exposed skin.

However, I am wondering if the human body is actually consuming (through biochemical reactions) any water or it is used entirely as a dissolvent or maybe as a catalyst), so that its loss entirely depends on the ability of reclaiming it externally.

Question: Does human organism consume water or is it only used as solvent?


texts: Why are the bodies of the Risso's dolphin covered in scratches?

texts: Risso's dolphin in wild population seem to obtain scratches with aging. What is causing them and what do they mean?


texts: How does the NAD+/NADH ratio affect lifespan in vertebrates?

texts:
Here's the proximate physical implication of the ratio (from the Wikipedia article on NADH).

  The balance between the oxidized and reduced forms of nicotinamide
  adenine dinucleotide is called the NAD+/NADH ratio. This ratio is an
  important component of what is called the redox state of a cell, a
  measurement that reflects both the metabolic activities and the health
  of cells. The effects of the NAD+/NADH ratio are complex,
  controlling the activity of several key enzymes, including
  glyceraldehyde 3-phosphate dehydrogenase and pyruvate dehydrogenase.
  In healthy mammalian tissues, estimates of the ratio between free NAD+
  and NADH in the cytoplasm typically lie around 700; the ratio is thus
  favourable for oxidative reactions. The ratio of total
  NAD+/NADH is much lower, with estimates ranging from 0.05 to 4. In
  contrast, the NADP+/NADPH ratio is normally about 0.005, so NADPH is
  the dominant form of this coenzyme. These different ratios are key
  to the different metabolic roles of NADH and NADPH.

So here's my question: how does this manifest in vertebrate aging? Is it something that's simply the resultant of other aging processes, or can the ratio also contribute to aging in a certain way?


texts: How many cell membranes are oxygen and carbon dioxide diffuse through in the lungs?

texts:
In the lungs, oxygen and carbon dioxide pass through cell membranes by diffusion.
Which row is correct?

The correct answer is D, but I think it should be B. I can only think about three layers as maximum which are; epithelium of alveolus, endothelium of capillaries and the membrane of red blood cell. I don't know what are remainings.

Any help would be much appreciated!


texts: Which infectious disease would increase global life expectancy the most if eradicated

texts: In the 1700s it was estimated, by Daniel Bernoulli, that wiping out smallpox would increase global life expectancy by over three years. If we could wipe out one infectious disease today, which would produce the largest increase in global life expectancy and by how much would life expectancy change?


texts: Components of the concept of Developmental Noise?

texts:
Developmental noise is a concept that correspond to the amount of possible phenotypic variance of a given genotype in a given environment.

Intrinsic noise (aka Cellular noise) is a component of developmental noise and it refers to phenotypic variations caused by the stochasticity of biochemical processes.

My question is:

What are the other component(s) of developmental noise?


texts:
Do trees have no set lifespan and
"quite"immortal?

texts:
Many trees survive centuries and die only in disasters like
storms and lightnings or infections. So do they have no set
life span? Are they exceptionally resistant to genetic
mutations and have very less cell cycle regulations which
keep them 'forever young'?


texts: How is the transcription direction of RNA polymerase determined?

texts: When transcription factors attach to the DNA strand - How do they know in which direction they have to initialize the transcription by rna polymerase? Is it always read in the same direction anyway? What about those 'promoters'? Do they influence the transcription direction?


texts: How credible is the Remenko's two-component color vision theory?

texts:
I've come across an article (in Russian), which describes a nonlinear two-component color vision theory made in 1975 by S. Remenko. The article heavily criticizes trichromatic theory as very imperfect. There's a whole page related to the criticism. Some of the citations there refer to Feynman's lectures vol. I ch. 35, where also some doubts are expressed. See e.g. the part by Feynman:

  Using the three different kinds of color blindness, the three pigment response curves have finally been determined, and are shown in Fig. 35–8. Finally? Perhaps. There is a question as to whether the three-pigment idea is right, whether color blindness results from lack of one pigment, and even whether the color-mix data on color blindness are right. Different workers get different results. This field is still very much under development.

But the only English-language place I've found mentioning Remenko's two-component theory was the book "Computer Systems for Healthcare and Medicine" by Piotr Bilski and Francesca Guerriero, where the first name also looks suspiciously Russian.

So I'm somewhat skeptic about credibility of all this Remenko's theory and the criticism of the trichromatic theory. But having not much expertise in color vision theories, I thus prefer to ask the experts: is the theory by Remenko actually credible? Is it even known outside of Russian-speaking world? Has it been falsified? Is trichromatic theory really flawed in any significant way so that a replacement theory would be required (are Feynman's remarks out of date?)?


texts: Is there a rule for the annotation of the basepair or gene locus origin in bacterial genomes?

texts:
Since all bacteria have one circular chromosome, there is no designated origin to start the systematic gene locus numbering. Therefore, what is the rule to start the numbering at a particular point (i.e. why is in the E.coli K12 strain the thrL gene given the ordered locus number b0001? If the answer is: It is the first Gene downstream of basepair-1, then why is basepair-1 at this particular position)

Why the question? Since bacteria show frequently functional synteny between genes, should I be surprised to find a gene frequently associated with the (arbitrary?) annotation origin? If the annotation origin is i.e. the origin of replication that would be an interesting case of synteny, but if no such rule exists, then such a case would most likely just reflect the historic sequence of Genome Sequencing


texts: I can imagine several specialized unicellular beings collaborating. But how does life get from that point to a unique pluricelular being that reproduces into another pluricelular being?


texts: In the paper they are infection WT and IL-22-/- mice with C rodentium on some occasions they use oral infection, on others they use IV and on some they use a bacteremia model. Can anyone please clarify why they may have done this?


texts:
What is the average speed of molecules in human cells?
Are there molecules moving much faster than others? What is it due to?


texts: Recent research in bioluminescence powering photosynthesis?

texts:
In 2013 there was a Chinese study published on "Bioluminescence as a light source for photosynthesis," which is briefly summarized in this Chemistry World article. There was a question on Biology.SE about a year earlier asking about the feasibility of such (and a somewhat related question for photovoltaics also in 2013).

My question here is if there is any newer research in the area of bioluminescence powering photosynthesis? Bonus if it is even more specifically related to any kind of crop production (so on a larger scale).

Please note:

I am not a biologist (last biology I took was AP Biology in high school a number of years ago).
From the other answers here on Biology.SE, I understand there is inefficiency with the use of bioluminescent light for "powering" things, but I'm still interested in more theory behind it as related to photosynthesis (hence the question about any newer research) for purposes of a fictional work I'm pursuing where sunlight is not an option. As a side question, imagine a "sky" of bioluminescence; would that be enough to grow some level of crops or trees?


texts: Can someone identify this odd looking spider?

texts: I found this spider crawling on my tile floor. We live in rural central Virginia.  I’ve found spider species with similar looks but nothing exactly like this. Its size was less than 1 inch. Can anyone identify it?


texts: Is the nuclear envelope present in G1 of interphase?

texts: Is the nuclear envelope present in G1 of interphase of eukaryotic cell? If so how does a method like Calcium mediated transfection get DNA past the nuclear envelope?


texts: Does increased calorie intake cause increase in libido in humans?

texts:
I'm interested in the effect of increased calorie intake on sex hormones and chosen mating strategy in humans.

I'm aware that humans have a dual mating strategy - somewhere between pair bond and casual mating. There are a number of physical measures to indicate this - such as sexual dismorphism between male and female, sperm counts and tested size, as well as age of puberty of females.

I've recently listened to a podcast that suggested that long term increased calorie intake causes differences between two mating strategies in case of apes. An example given was that gibbon ape filled their ecological niche and has no predators. Their population size is controlled by food supply. This makes food scarce and gibbons are more monogamous with more paternal investment (to teach offspring to forage)

At the same time another kind of savanna dwelling ape has natural predators limiting population and thus having more food supply. This ape has more offspring and less paternal investment and more promiscuity. It is as if they are more sexually active.

I'm interested if there is any truth to this and if this is also applicable to humans. Does increased calorie intake long term increases libido, while caloric restrictions reduce it?


texts: Virus cannot survive on surface after certain time period, but why and how?

texts:
I'm not a biology student at all, but I'm trying to get a clearer picture on what is meant by "virus cannot survive after a certain period".

To my understanding, a virus cannot be killed it can only be inactivated (for example, by means of heat and lowered pH).

So I really don't understand how can virus get inactivated by just being on a certain surface for an extended period.

I've come across numerous articles which told me virus won't survive on a surface. They usually focus on comparing the survival time between different types of surfaces but never touch on how the virus gets inactivated.

Can someone help me understand the "how"?


texts:
What is the title name for endocrine system + exocrine system?

In another language that I speak they are called "secretion system" but in English the term secretion system is different and it is about proteins in Gram-negative bacteria.


texts: Why don't rats have a gallbladder, unlike other rodents?

texts:
It has long been known that rats do not have a gallbladder, though other species including humans, monkeys, cows, reptiles, dogs and mice, all have a gallbladder.

In this paper from almost 100 years ago, scientists were studying what differences the presence or absence of a gallbladder gives the composition of bile. The authors found (what we now appreciate very well) that bile from mice who have a gallbladder was much more concentrated than rat bile - i.e. one of the functions of the gallbladder is to concentrate bile.

I know this is a very speculative question, but is it known whether having or lacking a gallbladder confers some sort of evolutionary or biologic advantage (or disadvantage)?


texts: Comparing Shine Dalgarno scores, creating a distribution

texts:
I am in the process of creating a poster for the phage that I recently annotated. The phage is an A4 and the portion of the poster I am working on is analyzing the data that we have collected. I have an excel sheet that has all the Shine Dalgarno scores for each gene that we annotated and decided was the best. Using mathematica I tallied all the data into a table and this is what I got (The x value of the list shows the score, the y value shows the amount of genes that had this score):

How can I create a distribution from this data? Would I need to use a Histogram, a plot, or some other graphic to represent the data?

Biologically speaking, can we make any observations about the genome from these scores?


texts:
When somebody else tells me about his or her itching or pain in some specific body part, I sometimes begin to feel similar feelings.

I can think of about three explanations:

I feel pain all over my body all the time for many different reasons but my entrance neural pathways stop it as unimportant of these signals but when I focus on a single signal, it begins to be important for me.
Mirror neurons are doing their job.
For an unknown reason, I psychosomatically induce my friend's feelings.

Which of these theories is at least partially engaged in said phenomenon?


texts: Can microdialysis be made in Drosophila melanogaster?

texts:
I've asked this before in stack overflow's cognitive science community, and someone recommended me to ask here:

I've found a couple of studies using microdialysis on insects, but didn't found any in Drosophila. I've found that the membrane diameter are from 240um, and it seems that Drosophila melanogaster brain must be between 200-300um , but I was wondering if the lack of studies of perfused drugs in Drosophila is due to this technical constraint, or is just I'm searching wrongly.

--
Edit: I specified the original target, Drosophila melanogaster, since there are bigger parients like Hawaian D. heteroneura and D. cyrtoloma. that could be subject to MD with current probes.


texts: Is it possible for bacteria to acquire family-wide antibiotic resistance?

texts:
If there is bacteria, lets say Enterococci that is sensitive to:

Amoxycillin-Clavulinic acid
Ampicillin-Sulbactam
Ofloxacin
Ciprofloxacin

Is it possible to become resistance to Ampicillin-Sulbactam by using Amoxycillin-Clavulinic acid ?

Is it possible to become resistance to Ofloxacin by using Ciprofloxacin ?


texts: Has any research lab done serious work to engineer new bacteria which assemble graphene wafers?

texts:
I was thinking about crazy uses for engineered bacteria. Nano-assembly of Graphene seems like a potentially excellent target for the technology. Have any research/full-blown labs worked on this? Any papers on it?
What would be some of the difficulties?


texts: What is the mechanism by which bactericides kill bacteria?

texts: "Bactericides kill bacteria". What is the meaning of "killing" in this context, and how exactly is this "killing" happening chemically?


texts: In mammals and birds the external reproductive organs and waste removal organs see to be the same. Is this always the case with other animals such as insects etc...? Are there any good reasons for it?


texts:
Does the hepatic portal system form capillary beds?  If so, is the capillary bed coordinated with that of arterial capillaries?

What review paper might I look in?


texts: Why does hair grow after trimming but remains at a constant length after a while?

texts: Some hair especially body hair regrows after trimming but stops growing after a while. What is the mechanism behind control of hair growth and how is the length limit determined?


texts: How specific is the adaptive immune response?

texts:
When you read about the adaptive immune response, you are often told that the response is specific to each pathogen - that the response is tailored. My question is - to what extent is this really true? And if it is true, how is the response tailored?

I understand that the B cell receptors (and, consequently, the antibodies produced by plasma cells in response to a pathogen) are highly specific. A pathogen will bind specifically to a B cell receptor on a particular B cell and particular antibodies will be produced for that pathogen. Again, T cells are specific for each pathogen.

But, it strikes me that there doesn't seem to be that much variation in what antibodies do. Each antibody is particular to its pathogen, but all antibodies work by doing the same few things, e.g. opsonisation, or inhibiting viruses from infiltrating cells. Yes the antibodies may be specific, but to what extent is it true that the antibody will produce a specific response to a specific pathogen? I mean, does the antibody for staphylococcus affect staphylococcus differently from the way the antibody for listeria affects listeria?

Again, each CD8+ Tc cell is specific to its pathogen, but they then seem to go about killing their target pathogen in very similar ways - inducing apoptosis or lysis via perforin and various cytotoxins. So, again, would the CD8+ Tc cell for influenza respond differently to the CD8+ Tc cell for norovirus?


texts: List of heritability estimates in humans?

texts:
Many people on this site ask questions that directly or indirectly have to do with heritability in human.

Do you know a list of estimates of heritability of various traits in humans? Or could you try to create such list?

That might be great to have various kind of traits, personality traits, life-history traits, morphological traits, …

I am not necessarily asking for GWA studies that inform about what genes explain the observed variance (although that would be really great) but just some estimates of heritability and eventually information about the method used (parent-offspring regression, twins, ...) and which population was studied.


texts: Botany practice questions for self-study

texts: I am studying for the USA Biolympiad. I have read Raven's Biology of Plants and Reece's Campbell Biology, but I am struggling to find plant biology practice questions. Can anybody recommend some resources with loads of plant biology practice questions? I prefer passage style questions rather than single-sentence questions that just test your ability to regurgitate facts.


texts: Measuring, using and analyzing skin resistance in kohms

texts:
What are ballpark ranges of skin resistance in Kohms for average men and their significance (for example 500-1000s = stressed vs 1000+ = fairly relaxed)

What do various skin resistances in kohms say about a person's emotional or arousal state:

For example:
Is a skin resistance of less than 0 possible and what what does that say about the person


texts: Human brain is superior than till-date computers, yet why we perform poor than computer?

texts:
Scientists found storage capacity of synapses by measuring their size.
They found, on average, a synapse can hold about 4.7 bits of information.
This means that the entire human brain has a capacity of one petabyte.
This is same as about 20 million four-drawer filing cabinets filled with text.

Striving around this stuff, I have a weird doubt crawling in my mind and it goes like this: Why is it like this that a human whose brain has got a capacity to store 1 petabyte, i.e. 1 million GB, cannot fully remember even the contents and information of a simple textbook which on the maximum would not be more than 1 GB, when he has to appear in exam? Why is storage capacity not directly linked with remembering capacity?


texts: Help identify these (two) fishes - Netherlands

texts:
Yesterday my kids caught these two fish. I tried to figure out what kind of fish (species and name, to tell my kids a bit more about them) they are but I was not successful. Today we made a trip to a nearby sea-life exhibition which exhibits native sea animals but I couldn't find similar fishes there :-)

They were caught in Callantsoog (north-western Netherlands) in salt water in shallow water next to a breakwater wall at low tide.

This is the first fish. To me it looks like some kind of catfish.

It is approx. 10 cm long.

This is the second fish. To me it looks like some kind of eel.

It is approx. 20 / 25cm long.


texts: How and why did mammals go back to the oceans?

texts: If I understand evolutionary biology correctly, mammals first evolved on land as small, rodent-like creatures, in a time when reptiles were dominant on land. Eventually, they diversified into the species we know today. Some of these species, however, are aquatic - whales and dolphins readily spring to mind. Why did the ancestors of whales and dolphins leave the land to go to the oceans? How did they evolve from their original form to their superficially ichthyoid appearance today?


texts: What is Colloidal biology and does it have any scientific background?

texts:
There is the following bulletin published for the History of Chemistry Vol. 32: 105-118 in 2007:

“MOLECULAR” VERSUS “COLLOIDAL”: CONTROVERSIES IN BIOLOGY AND BIOCHEMISTRY, 1900–1940*

written by PhD habilitation research professor Ute Deichmann at the Leo Baeck Institute (LBI) in London and leader of the History of the Biological and Chemical Sciences Research Group at the Instritute for Genetics, University of Cologne.

Therefore, the question is: What is Colloidal biology, what are the basic differences between molecular biology and does it have any background in modern scientific community?


texts:
Image description: text reads "An $F_1$ x $F_1$ self gives a 15:1 phenotypic ratio in the F2. What phenotypic ratio would you expect if you test-crossed the F1?"

How do I find out the $F_1$ phenotypic ratio by using the given $F_2$ phenotypic ratio?
What method should I use to solve?


texts: Strange Striped Insect identification (Northern Indiana)

texts:
These bugs are coming out of some wood that I cut and burned in Northern Indiana (USA) . I am not sure if it is coming out of a white ash, cherry or oak.  We did have the emerald ash boarer come though the area -- is this an ash boarer?

Thanks.


texts: Why is a slow worm not considered a snake?

texts:
Slow worms are considered lizards as opposed to snakes, both are reptiles. Now I get that there are traits that distinguish them (eye lids, ears ...). But snake species themselves vary already quite a lot.

The Wikipedia article on snakes states:

  Based on comparative anatomy, there is consensus that snakes descended from lizards.

But how comes slow worms are considered lizards despite the loss of their limbs during evolution, whereas the same evidently has happened to snakes?

What's the defining factor here? The time frame when it happened, that it happened independently (like the evolution of, say, an eye)?

Note: I couldn't find any detailed descriptions about the alleged evolution of slow worms, whereas for snakes it is easy to find material.


texts:
If a ribosome is made of protein, yet is used in protein sysnthesis, what created the first ribosome?

What created the ribosomal RNA?


texts:
For computer modeling purposes, I am looking for some referenced quantitative measurements of the effect(s) of temperature on biochemical reactions.

Question

In particular, my question is:

How does temperature influence the rate of protein degradation?

Reducing the scope of my question

My question might be too broad in the sense that there might have too much variance in how different proteins respond to temperature in order to draw in general tendency. If this is so, someone willing to answer may reduce the question to transcription factor, to General Transcription Factor (GTF) or even to TFIIA.

I am NOT looking for..

I am not looking for a theoretical explanation of how temperature influences this process (I have basic understanding of the importance of the activation energy as displayed on a Maxwell-Boltzman distribution and of the Michaelis-Menten equation).

I am looking for..

I am looking for a function that I can plug in my algorithms to incorporate the influence of various temperatures on the process I want to simulate. I want to simulate the average gene network from an average standard eukaryote. For other purpose, I chose parameter values coming from the yeast. A index such as the Q10 would be very useful as well.

Similar already-answered question

Similar questions have been asked and answered here and here


texts: Why do neutrophils have segmented nuclei?

texts: To clarify, I'm not asking what causes high segmentation in neutrophils. I'm asking how segmented nuclei function in a regular neutrophil cell.


texts: Why must gene entrapping constructs be integrated into introns and not exons?

texts:
Homework Question:

In enhancer trapping, reporter transgenes are integrated randomly into the fly genome and their expression identifies enhancers and thereby genes expressed in particular patterns. In mice, a similar technique for gene identification is employed called “gene trapping.” In gene trapping, an exon encoding a reporter protein such as GFP (see below) is integrated into random locations in ES cell chromosomes (when DNA constructs are introduced into mouse ES cells, most recombination events are into random sites; homologous recombination is relatively rare). ES cell lines with randomly integrated transgenes are used to generate mice.

Where in the genome must a gene trapping construct integrate in order for ES cells to express GFP?

Answer:

My Question:

Why can't the construct simply be knocked into the coding DNA sequence of the mouse genome? Why does it have to be integrated into an intron?


texts:
Today, when I just woke up and saw this. I need to identify the species of this mosquito. I don't think its dangerous like Female Anopheles. I'm afraid if it is a carrier of any dangerous diseases such as Filaria, Dengue, etc.

Location: Bokaro, Jharkhand, India

Temprature: $ 29°C $


texts: What kind of a microscope do I need to see cell organelles?

texts:
I would like to study cells and looking for a microscope that would allow me to see:

groups of cells
individual cell
cells organelles

I would like to target insects and mammal tissue.
I would be very grateful for info in magnification ranges that I need and maybe some popular models of microscopes.

Is there a difference between digital and non-digital microscopes for that purpose?


texts: Why in some cells is GTP made in citric acid cycle and in some ATP?

texts: In many  animals GTP is produced in citric acid cycle. While in  plants,bacteria and some animals ATP is produced. Why is this so ? What is the advantage ?


texts: Could you identify which species of ant is this queen?

texts:
could you identify which species of ant is this queen. I caught it in Bangalore, India. I caught it after a rain at around five to six.

]2


texts: Good model for comparative genomics in relation to temperature adaptation

texts:
Can anyone suggest any highly related bacterial or parasitic species which live at very distinct temperatures, which might be a good model for comparison of genomes in regard to temperature adaptation. For example, related pathogens of which one species infects warm blooded animals, and the other infected cold blooded animals? So far I have come up with one possible example: Salmonella enterica is a pathogen which infects warm blooded animals, whilst Salmonella bongori infects mainly reptiles.

Examples for which there are publicly available genomes, and which have been used in previous studies would be preferable.


texts:
I have the following question in systems biology:
a) Draw a graph showing the relationship of growth (Vbio) and Vefni for the system here. (Let the horizontal axis represent Vbio and the vertical axis represent Vefni)

My first thought was that it would simply be straight line from (0.5,0.5) to (1,0). But now I'm thinking that I have to take V4 into account as well.

b) Determine one or more reactions that are such that if they are taken
out the production of M4 is coupled to growth (growth-coupling). Draw a
graph showing the relationship Vbio and Vefni for the mutant.

Here I thought it would be V1 and V4. I'm not sure though because I haven't found a good explanation for what growth-coupling is exactly.

c)  Why is it desirable to couple chemical production to growth? i.e. what advantages do those systems have over the ones where no such coupling is present?

Here I have no idea.


texts: Reconstituting genomes of archaic tribes of humans

texts:
Will it be logically possible for genome studies to reconstitute the genomes of our local human populations as they were 2000 and 4000 years ago? What is the mathematical precision and science for that kind of thing?

I am fascinated by human facial features and i wonder what our archaic tribes looked like regionally when they were isolated, a few thousand years ago, before mixing into the melting pot that they are today.

If we can one day image facial construction from DNA using some thousands of facial genes, it will be cool if we can also find what local dna pools were like precisely a few hundred generations ago. Is it possible?


texts: How are newly synthesised proteins targeted to the plasma membrane?

texts:
There does not seem to be a definitive answer to how proteins destined to be intrinsic plasma membrane proteins are directed there. Presumably, assuming starting at a cytosolic ribosome, the pathway is via the SRP/Sec61 translocon system into the ER co-translationally, followed by COPII vesicular transport to the Golgi for modifications.

From here, is the system that of COPI transport back to the ER? I think I read that if sitting in the ER membrane, proteins can 'slide' into the PM via some vague endomembrane system juggling. Or, packaging into vesicles which can then fuse with the PM?


texts: What is known about major events of pre-LUCA evolution?

texts: All organisms share many common biochemical features (including 20 amino acid genetic code) and are believed to have a common ancestor (so-called LUCA). According to wikipedia article, this common ancestor was quite complex organism with advanced biochemistry. Are there an knowledge about evolutionary events occurred during pre-LUCA era? Namely, which of biochemical pathways already present in LUCA were evolved earlier than anothers?


texts: Why do animals yawn? What is the biology behind it?

texts: We yawn whenever we are tired and body needs rest. Why does the mouth open wide and a large volume of oxygen is inhaled?


texts: What characteristics of the protein folding process ensure that the energy landscape is a funnel?

texts:
The folding funnel hypothesis states that the energy landscape that proteins observe when they fold is funnel shaped with a single global optima. This ensures that no matter what sequence of folds the protein follows, it should eventually end up in the same folded configuration thanks to the laws of thermodynamics.

For example, see this illustration of the energy landscape from Dill & MacCallum (2012) "The Protein-Folding Problem, 50 Years On" Science 338 (6110) pp 1042-1046:

Clearly, the folding works because the energy landscape is funnel shaped. Any other configuration, e.g. a landscape with multiple significant local optima or a flat landscape, would result in a protein folding in all kinds of different ways.

What are the characteristics of the overall system that ensure that the energy landscape is funnel shaped, and that nearly any protein in an unfolded state will reach the global optima? (e.g.: is it because the proteins themselves have certain statistical properties? or it is something to do with how the types of "moves" the protein makes on the energy landscape?)


texts:
I am confused about the prerequisites for cell division and cancer.

Which of the following is necessary for the cell cycle to progress?

Hormones
Growth factor
Cyclins
Cyclin dependent kinases

Which of the following is essential for cancer proliferation?

Growth factors
Signalling molecules
DNA replication
A control mechanism

How do the cell cycle and cancer relate to each other?


texts: Can I use yogurt to prevent the growth of black mold?

texts:
I have a mold problem in my bathroom.  There is a narrow groove between the top of my tub and the wall it is attached to where a black gunk repeatedly grows.  I can shoot the material out with a spray bottle but it grows back.

I've been taught many times that a bacterial film can prevent the growth of other bacteria, because the film created by one prevents another from colonizing that spot.  I have the inclination to think yogurt has bacteria.  If I were to clear the groove of the material, then spray the groove with a mixture of yogurt and water, would the bacteria in the yogurt colonize the freshly cleared groove and prevent the growth of what I assume to be mold?

I assume this is on topic as I am looking for a sort of corroboration/rejection of this scenario rooted in the biological workings of bacteria.


texts: Does "RT-PCR" denote "real-time PCR" or "reverse transcription PCR"?

texts: I often find the term "RT-PCR" used in articles without any further qualification. Searching for the meaning of the acronym sometimes leads to "real-time polymerase chain reaction" and sometimes "reverse transcription polymerase chain reaction." I understand that reverse transcription PCR uses a reverse transcriptase to convert RNA to DNA, which is then amplified by the usual PCR method. I'm not sure I understand what real-time PCR is, but it sounds to be distinct from reverse transcription PCR. Are these distinct methods that happen to have the same abbreviation? Or do they somehow mean the same thing? What is usually meant by the acronym "RT-PCR"? Is there some context I can use to distinguish them?


texts: What are the determinants of tumor metastasis

texts: Under what conditions do tumors migrate? Is it due to hostile microenvironment conditions, drug application, mutations, or other causes? Are there any migration probability values (I am doing an in silico research) or equations to determine this?


texts: How do biologists infer correct ORF of a DNA sequence?

texts:
Each DNA (RNA) sequence has 6 possible Open Reading Frames(ORF). My question is: What are the theoretical bases of in vitro or in silico tries to find correct reading frame of a sequence?

Is it just distance between Start and Stop codons, or are there some other factors with more important impacts in this subject?


texts: Vitamin D oral intake, transportation and absorption

texts:
Several factors affecting vitamin D and its active form absorption and storage

acidity of stomach (not significant effect)
cytopathic effects of viruses
cytopathic effects of bacteria

where the last two reasons can be some reasons which may explain why vitamin D should be administered with bread; to make a surface covering around out vitamin D molecules.
Probably, the fibers also work in some short of transport media.
They can also partially explain why big dose of vitamin D does not last long time in the normostenic body.

Summary of procedures in administrating vitamin D orally

with bread (carbohydrates; fibers) - possible protection, better transportation and more to absorbtion
with oils (fat metabolism could help in destroying extra free radicals; but I see no other sense in administrating vitamin D with fish oils)
daily (not weekly)

Why does the lipid-soluble vitamin D not last in the body long time?


texts: Why doesn't telomerase activity cause DNA to get longer each time a cell undergoes DNA replication?

texts: Telomerase extends the ends of the lagging strands in order for all of DNA to be be copied. Doesn't this also mean that DNA gets progressively longer each time it undergoes replication? Why is this not the case?


texts: Why don't cells double gene expression after S-Phase?

texts: In the cell cycle (G1-S-G2-M), all of the DNA is replicated during the S or Synthesis stage. The cell may then spend some considerable time in the G2 phase before splitting in the M phase. Since there is double the amount of genetic material in the G2 phase, what mechanism if any, prevents the amount of gene expression from also doubling?


texts: Could all mammalian receptors be described as allosteric?

texts:
Allosteric regulation in enzymes is where a molecule binds at a site other than the active site and thus changes the tertiary structure of the active site, hence altering the binding of substrate and formation of enzyme-substrate complexes.

As I understand it, if this is extended to receptors, for example G protein-coupled receptors, which effectively causes a conformation change which is transmitted across the membrane and 'activates' a G protein which is associated with the receptor. The Gα subunit swaps a GDP for a GTP which causes the dissociation of the alpha from the beta-gamma coupled subunits and from the receptor. The dissociated Gα and Gβγ subunits then take part in a cascade process interacting with other molecules.

However, photoreceptors such as rods/cones in the eye respond to light. These photons tend to cause changes in the structure of the rhodopsin/iodopsin pigments and not the actual 'receptors' themselves. G proteins do seem to be involved in this process too.

Therefore, are photoreceptors allosteric? And if not, are they an anomaly in mammalian receptors, or are there many other examples of receptors that do not rely on allostery?


texts: Cannot conjugate Biotin-labeled DNA to Streptavidin-labeled solid surface

texts:
I have been trying to immobilize DNA by the bioconjugation of biotin and streptavidin, but I cannot get this work.

I added EDC and streptavidin to COOH functionalized resin, reacted for 3 hours in room temperature, and then washed with PBS.

Then I tried to anneal biotin-labeled primer and FAM-labeled complementary sequence. (Heated it up to 95 degree then let it cool down to room temperature.

After I added SA-functionalized resin and FAM-Biotin strands together, the conjugation wouldn't work. The resins are not fluorescent after wash.

I also tried to use PCR products which are labeled on both side.

Is there any problem with my assay? How long it takes for the conjugation of biotin and SA at very low concentration?

Thank you for any information.


texts: Suppose the Hayflick's limit of a cell is 10 and it divides 10 times.  At this point, it undergoes differentiation.  Is it possible for it to undergo dedifferentiation at this point?


texts: Microscope recommendation for an amateur?

texts:
I am a mathematics student looking for a hobby and this has come up as a potential hobby. Thus I am interested in buying a high-magnification microscope that is within the limits of my budget.

My first question is, is high-magnification always better? That is, what are some examples, if any, where high-magnification isn't preferred?

Secondly, I am thinking of getting either the "OMAX 40X-2000X Digital Lab LED Binocular Compound Microscope with Built-in 1.3MP USB Camera and Double Layer Mechanical Stage". I have no idea what most of that jargon means, except that it is digital and it can magnify up to 2000x. http://www.amazon.com/40X-2000X-Binocular-Compound-Microscope-Mechanical/dp/B006MX03Q0/ref=pd_sbs_indust_4

Is there any reason I shouldn't get this microscope?


texts: How long can an infant human hold his/her breath as part of the "dive reflex"?

texts:
Various other questions on the site have talked about the Diving Reflex, which is also known as the Mammalian Diving Reflex. This reflex is observed in mammals of various species, but also in human adults and infants. A number of studies have been done examining the diving reflex (e.g. Advances in Physiologic Education).

If you've ever observed an infant submerged in water (e.g. at a swimming pool) who has this reflex it seems so amazing because the baby will spontaneously hold his/her breath while submerged.

Are there any estimates of long an infant will hold his/her breath as part of the dive reflex?

Obviously this is dangerous to try and test this in the real world, but I'm wondering if anyone has any idea. This reflex seems so remarkable to me because unlike the adult human who knows they shouldn't breath in water, I would think that the baby doesn't know that at such a young age.


texts: Which cells release inflammatory mediators?

texts:
Wikipedia says

  Inflammation is stimulated by chemical factors released by injured cells and serves to establish a physical barrier against the spread of infection, and to promote healing of any damaged tissue following the clearance of pathogens.

then it mentions

  The process of acute inflammation is initiated by cells already present in all tissues, mainly resident macrophages, dendritic cells, histiocytes, Kupffer cells, and mastocytes. These cells present receptors contained on the surface or within the cell, named pattern recognition receptors (PRRs), which recognize molecules that are broadly shared by pathogens but distinguishable from host molecules, collectively referred to as pathogen-associated molecular patterns (PAMPs). At the onset of an infection, burn, or other injuries, these cells undergo activation (one of their PRRs recognizes a PAMP) and release inflammatory mediators responsible for the clinical signs of inflammation.

From this we can clearly deduce that the inflammatory mediators are released by Pattern recongintion receptor producing cells. But while studing this topic from different sources some, books on nursing and Pharmacy. They keep repeating that inflammatory mediators are released by injured cells.

What is correct?


texts: What is the conical mouthpart of a soldier termite and what does it do?

texts:
I'm trying to get a visual understanding of termite anatomy and I'm getting quite confused on the protruding mouthpart area (it looks like a beak) located between the pincers.

What does it do / what is it for? It does not look like a chewing mouthpart.

Further, is it related to the mouthparts of the worker / females termites?

Oddly enough, I found "Conehead" termites with what appears to be a far more profound version of this part (though it might not be) and again I see no purpose for it.

Is there a place on the internet where the breakdown of termites can be found? This would be very useful.

What is between the pincers?


texts: Which class of animals constitute the largest biomass?

texts: I found here that species-wise it is cow. But, collectively, insects may exceed even mammals. So, which class of animals constitutes the largest biomass?


texts: Why do fishes have both a gustatory and an olfactory system?

texts:
I would like to know if there is a reason why fishes (and many aquatic species) have both an olfactory and a gustatory system. As far as I know, in all fish species the chemoreceptors, organs and neuronal pathways are different for taste and olfaction, but why is it an asset to have two distinct sensory systems for chemical compounds in an aqueous medium ?

For terrestrial animals it makes sense to separate information stemming from remote sources mediated by volatile molecules and from the oral cavity, where the molecules are everything one can find in food. But in aqueous medium this distinction is far less obvious, especially when one considers that in some species there are taste receptors located on the body surface (lips, barbels).

I've read a few articles and this thread describing the physiological and neurological aspects of this separation, but it's not answering my question (and it actually aroused my curiosity even more).


texts:
Does anyone know of an .NET (C#,VB.NET, maybe F#) DNA parser?  If not I will probably make one, it doesn't seem like it would be hard.  My general idea was to generate something that would report the codon biases and go back and adjust the bias for engineering.

I realize the later part is a bit specific, but if anyone knew about an open .NET program that annualized/parsed the codon bias, I'd be interested.

Thanks.


texts: Finding a template/oligo combination for my first PCR experiment

texts:
I'm an information technology engineer. I love biology so I research biological topics and have an interest in PCR. That's why I have decided to create a PCR machine.

Everything is done now and I want to do my first experiment to see if it works or not. I would be very happy if someone could give me any suggestions for testing it at home. Which oligo should I use for testing in the easiest way? I mean a template DNA for testing that is easy to find and extract.


texts: Is it possible for a human to wake up in a wrong way?

texts:
There's an old folk saying that goes like "He got out of bed on a wrong foot" - to indicate that the person's day is going poorly because of the way that person woke up.

Is it is possible for a human to disrupt the awakening process, causing negative cognitive side effects for the rest of the day? If so, how long does it take to restore normal cognition?

There's this related question that I asked - if different parts of a human brain can be asleep independently of each other? This question is a variation on that one, and specifically deals with the process of awakening or activating brain regions in the morning.

I'm aware of the concept of "Sleep inertia". However, it does not seem to be the phenomenon in question, as sleep inertia is frequently mentioned in the context of napping. (where napping over a certain time leads to sleep inertia). Additionally, sleep inertia has been described in terms of decline of motor activity, and not as cognitive side effects lasting for a whole day.

From personal experience, it seems that I'm doing best if I get out of bed immediately following a natural awakening, even if it is rather early, as opposed to snoozing for another 30-40 minutes.


texts: Is HSV-vector-mediated miRNA expression in dorsal root ganglia stable?

texts:
My question is on the following article:

"Reduction of voltage gated sodium channel protein in DRG by vector mediated miRNA reduces pain in rats with painful diabetic neuropathy"

My question is, do you think the rats continued to have decreased levels of voltage-gated Na+ channels after this experiment, or did they likely gain them back up eventually, because dorsal root ganglion neurons regenerate themselves? I couldn't find this info in the article.


texts: What properties of the pathogens of infectious diseases make recovered individuals susceptible to the disease?

texts: I was wondering what properties of the pathogens of infectious diseases make these diseases more prone to making recovered individuals immediately susceptible to the disease? I was thinking that with Salmonellosis, for example, there are different variants of the Salmonella type of bacteria, but I'm not sure if having more variants of a pathogen necessarily makes it more difficult for the human body to recognize these pathogens.


texts: Chromosomes are of different size but why do all chromosomes have similar GC percentage?

texts:
When I browsed NCBI I saw a pattern: even if the chromosome sizes, number of genes, and number of proteins are different, GC% in chromosomes tend to be similar. The examples are linked below.

Yeast,
Plasmodium falciparum

If you see Mitochondria genome it is not very similar to chromosome. Why all chromosomes tend adjust their GC% near to the average of total GC%
Is there a specific reason related to metaphase of meosis?

to further clarify I have some images to help

The chromosome size or genes in an organism are not adjusting near the average of their total but GC% does. It has only 3-2% (falciparum) or 3-4% (vivax) variation in GC%. It feel like its balancing like equalizer. Why?


texts: Species Identification : Worm like insect but broad at back

texts:
Can anyone help me identify this insect

Location: Southern India

Size: About 2cm

It looks like a worm but has a broad back, it seems like (not very sure) it tucks it's thin head inside the broad shell like body to ward off.

Here is the picture,


texts: How can bobcats feel the mice under the snow?

texts: I've just seen the Planet Earth II's second episode "Mountains" where they shock us with these North American bobcats that can feel mice from the distance of several meters, sneak to them and kill them with a single jump. What is their biggest source of information about them? The smell? Feeling of the quiet rumbling of the earth? Hearing it? Any of it seems almost impossible to me, with regard to the conditions of the polar regions.


texts: The difference between the two ways of glycine represntation

texts:
I'm confused because I see now two different way to represent the glycine amino acid. while I understand the first way of the representation the second one I don't understand at all. I believe that both represent the same amino acid but I see that some of the componenets are absent in the second way (no COOH and no carbon). I would like to know the explanation.

This is the first (and the simplest way):

and this is the form that I don't understand:


texts: How to quantify the Abundance of a particular gene in Bacteria and Archaea?

texts:
For 16s rDNA metagenomic analysis, do I need to do the following steps?

  DNA extraction-> Purification-> PCR amplification-> Clone -> Pick every single
  colony-> PCR amplify -> Sequence -> Phylogenetic Analysis

For the abundance of a particular gene abundance, what steps do I need to follow? Is it necessary to clone?

`


texts: What is the known maximum ranging distance of a bat's sonar?

texts:
Bats are known to navigate by using echo-location.

How far away can a bat detect an object by its sonar?


texts: Can you grow more Biomass in a brickhouse only powered by solar cells than in a greenhouse? Will we ever be able to?

texts:
So I asked following question some physicists but they couldn't really help me though:

  Right now I read that 1m² of solar cells generates roughly 100Watts of
  energy. There are really efficient Grow LEDs that use only two spikes
  in the lightspectrum to make plants
  grow.

  I have seen some graphs like the Quantum Efficiency of Sola
  Cells
  that suggest that solar cells can absorb energy in the range of 400nm
  up to 1200nm (in varying degrees of efficiency).

  By my logic (given a high enough overall efficiency of the solar
  cell), a solar cell can make light that is most of the time reflected
  by plants in the range of e.g. 500nm-600nm / or 800nm+, into
  electrical energy, and that electrical energy can be used, in turn, to
  produce light in the range of 400nm and 700nm that the plants can use
  again for photosynthesis.

  Additionally, i could imagine that the sun sometimes hits the range of
  diminishing returns in terms of brightness (lux, lumen?) when it's
  really really bright and hot and shining directly on the plants.
  Instead it would maybe be more efficient to capture that energy
  (photon) and convert them only to the wavelength needed in enough
  brightness that plants can grow (again, given a high enough solar cell
  efficiency, right now it's 20%, i heard 40% is a theoretical limit?)

  You could phrase the question a little bit different: I have 1m² of
  land and two possibilities:

  build a greenhouse and plant 1m² of crops
  build a brickhouse as high as I want with as many layers of 1m² levels. But they are only allowed to be lighted with LEDs and no
  direct sunlight. And the LEDs are only allowed to be powered by 1m² of
  solar cell on the roof.

  What is the needed solar cell efficiency (generated watts/m²) for the
  solar cell to reach the break even point of total biomass production /
  timeunit between case 1. and 2.

  If there are other environmental conditions that would benefit only
  one of these cases, assume in favor of case 2 and mention the
  variable.

  I was in a heated discussion about this yesterday and I would love for
  someone who knows more then me to help me wrap my head around this.

So, to give some extra Information for you guys or to rephrase it again to increase the chance to get an answer: current solar cells operate anywhere from 100W-200W/m² with an upper limit somewhere around 400W to 450W for the way we do it right now. (100W is 10% efficiency, 20% are high quality PVCells right now)

Thanks a lot!


texts: Need help designing an enzyme immunoassay (EIA)

texts: I have a FITC-labelled DNA sequence and an anti-FITC antibody, however this antibody is not conjugated with HRP or any other enzyme. I work in a lab with limited finances, so is there a way I could make use of these without having to order an HRP conjugated antibody to be used in a detection assay?


texts: How can I get started in molecular biology?

texts: I have a background in computer science and math and am interested in learning molecular / synthetic biology - what resources do people recommend?


texts: How do Gram + bacteria use a proton gradient for F-type ATPase?

texts:
Does anyone know of any papers showing how Gram positive Fermiculates or Actinobacteria use  a H+ gradient for an F-type ATPase, It seems impossible since there is no outer LPS membrane to maintain the protons in a periplasmic space. Is the use of ATPase for production of ATP exclusively a Gram negative thing?

I found this question "Production of ATP in Lactobacilli" but no answers:
https://biology.stackexchange.com/questions/14669/production-of-atp-in-lactobacilli


texts: How does the enzyme Dicer function in the RISC complex?

texts: I know that the RISC (RNA-induced silencing complex) is one of the primary complexes involved in gene regulation through RNAi.  What I want to know is, what role exactly does Dicer play in this complex?


texts: Where can I buy paracoccus denitrificans? I need it for an experiment. I cannot find online where I can purchase this.


texts: How to know the gestation time of pregnant mice?

texts: In lab mice I wish to establish how many weeks my animals are into their pregnancy. Is there some way?


texts: Is there a difference between "genetic cross regulation" and "crosstalk"?

texts: What is the difference between genetic cross regulation and crosstalk? I'm a physics major and learning about bioinformatics now. So it might seem trivial to many but from the article "Wanner BL. Minireview. Is cross regulation by phosphorylation of two component response regulator proteins important in bacteria? J Bacteriol 1992; 174:2053-8." I could not find a quantitative way to separate these two kind of gene regulations. Also, I would appreciate if anyone can suggest me something to read for further knowledge on this topic. Thanks!