texts: Producing a genetically modified animal with cell walls

texts:
I'm curious if there has been any genetic experiments transferring cell wall producing genes into the genome of a animal model organism such as the fruit fly (Drosophila melanogaster) or a larger animal such as a mouse (Mus musculus).

If there hasn't what do you think would happen, if anything at all?

Thanks!


texts: What does "rapamycin-sensitive oncogenic transformation" mean?

texts:
Can someone explain exactly what "rapamycin-sensitive oncogenic transformation" is? I get that it's a drug that suppresses the immune system but what does it have to do with oncogenic transformation?

Here's the article where they talk about it:

http://www.pnas.org/content/104/13/5569.full


texts:
According to Psychcentral depression, bipolar disorder, ADHD, schizophrenia and autism are traceable to the same inherited genetic variations

According to AsapSCIENCE, depression could be genetic due to a variation in the serotonin transporter gene. Having at least one short seems to give some kind of genetic predisposition to depression.

So what's the analogue of the serotonin transporter gene in ADHD? Is there a dopamine transporter gene?

Double posted on Cognitive Sciences Stackexchange


texts: How many human proteins have a solved 3D structure?

texts: I was wondering how many human proteins have a solved 3D structure. Is there a database with only human proteins? I looked at pdb but couldn't find a filter.


texts:
The telomerase is an enzyme that adds telomeres.

What stops the telomerase from adding too many telomere sequences ? What's the regulating mechanism ?


texts: Why don't we develop immunity against common cold?

texts: We all suffer from common cold, and that, frequently. Why have we not developed immunity against it till now? By immunity I mean immunity as a species.


texts:
I am confused as to what endocytic processes are termed specific and non-specific.
I am only sure of pinocytosis as a non-specific process but I can't successfully put phagocytosis in the right category. Worse still, there are contrasting views in many sources four of which I have attached their URL.
In my opinion, as phagocytosis requires ligand-receptor interactions, it should be specific. But then phagocytosis has been known as a mechanism of innate immunity, a supposedly non-specific form of defense.
I am so confused.
(In support of specificity)
1.
https://www.khanacademy.org/test-prep/mcat/cells/transport-across-a-cell-membrane/a/phagocytosis
2.
https://www.immunology.org/public-information/bitesized-immunology/systems-and-processes/phagocytosis
(In support of non-specificity)
1.
https://www.cliffsnotes.com/study-guides/biology/microbiology/nonspecific-body-defense/phagocytosis
2.
https://www.sciencedirect.com/topics/medicine-and-dentistry/phagocytosis


texts: Where can I find a diagram of cortex connections?

texts:
Has anyone come across a diagram (2D, 3D, maybe even interactive) of the connectiontions between cortex regions? Especially, the diagram should display the strength and direction of those connections (but not every single axon). I am interested in information like "Brodmann area 7 receives heavy connections from area 1,2,3 and 17,18", displayed in a neatly arranged way.

If there is no diagram that fulfills my need, is there another source of information, like a table, where I can find that sort of information?

Edit: After some more research I found this paper which contains some interesting diagrams in its appendix. However, this paper does not describe the human brain.


texts:
I live in south-west Germany and today while mowing the lawn I discovered a strange structure. It looks like a molehill on which additional branches were placed. This kind of branches are easy to find in my garden, because they were removed from the trees by a strong wind. However, I have no explanation for this accumulation of branches on a small mound of earth. I have seen an animal that looked like a rat in the last few days.... But I think a rat would not build such a building? What kind of animal lives in my garden?
Additional Picture:

I would like to edit my question to provide the additional information requested by "tyersome":
There were high winds about two days before I discovered this structure. However, what is disconcerting to me is that there is obviously soil under the branches here, and the branches are conscientiously piled up.  The other branches are widely scattered in the garden. There have often been strong winds, but a similar structure has never been created before. I have been unable to detect any other signs of animal activity associated with this structure. I have left the structure undisturbed and have not investigated it further so far, as I believe it to be an animal burrow and I do not want to cause any disturbance to the inhabitants. Thus, I have not cut the grass around this structure, but have left it standing. Animals that can be observed in my garden are for example: pigeons, squirrels, other birds, mice.
Second Edit: There are trees nearby. Could it be a bird's nest that fell out of a tree? In addition: Is it safe for any occupants if I examine the structure more closely or turn it over?
UPDATE:
Day 2: Encouraged by your valuable comments, I examined the structure more closely today. Turning it over showed that it is probably, as you suspected, a bird's nest. There was also no entrance in the ground where the structure was located. I could not find any eggs or feathers. Therefore, the species of bird that built this nest remains unknown. The nest has a total diameter of 80 cm (31 inches). The diameter of the inner ("soft") nest is about 20 cm (8 inches). I didn't expect such a big bird's nest in my garden.

The nest may have fallen from this tree:

UPDATE (10. May 2021):
Since I had to assume that additional information would be needed to determine the species, I again examined the area extremely carefully today. In doing so, I was able to find eggshells that were located near the tree. I cannot say with certainty that these eggshells are directly related to the nest, but it is likely.

Then I researched, which bird eggs might correspond to these.
Based on the appearance of the eggs, I suspect the following species: The Common Blackbird (Turdus merula), the Eurasian Magpie (Pica pica) and the Eurasian Jay (Garrulus glandarius).
I have observed each of these species in my garden:
The Common Blackbird: very often,
the Eurasian Magpie: occasionally,
the Eurasian Jay: occasionally
Wikipedia states that the eggs of the Common Blackbird (Turdus merula) are  2.9 × 2.1 centimetres (1.14 × 0.93 in) in size.
The eggs of the Eurasian Magpie (Pica pica) "measure 32.9 mm × 23 mm (1.30 in × 0.91 in)".
However, I could not find any information about the size of Eurasian Jay eggs.
I would guess that the blackbird is too small to carry the large branches that are used in the base of the nest. I have also seen a blackbird's nest in a bush in my garden: I think the eggs were smaller and the nest was also made of much finer material.
So the Eurasian Magpie, as stated by "tyersome", is a very hot candidate for me. Can this be confirmed from the eggshells?


texts: Do people live longer only because of better hygiene, medicine, society etc or also because they're slowly evolving to live longer under same circumstances?


texts: How fast will cells lyse under hypotonic conditions?

texts: Routinely, lysis of cells with hypotonic solutions is carried out along with some physical (douncing) or enzymatic (lysozyme) method to break open the cells. If one were not to do any of these and just resuspend cells in water, how long would it take to lyse the cells? I was discussing with a lab mate who claimed it would take hours while in my understanding, salt equilibrium should not take very long (maybe on the order of minutes?) and hence, lysis should be done within 20-30 minutes.


texts: Magnetic-activated cell sorting vs. FACS

texts:
When sorting cell populations it is possible to use either magnetic-activated cell sorting or fluorescence-activated cell-sorting (FACS). I am wondering when you would choose either technique and what the pro's and con's of each technique are.

As FACS sorts cells one by one, I can imagine magnetic-activated cell sorting is a faster process. So I guess if time is an important factor this could be used to base your decision on. Also by sorting cells one at a time I assume FACS is a lot more precise, and will lead to less 'contamination'.

So, are there other factors at play here that can influence the choice of magnetic-activated cell sorting over FACS, and what are the pro's and con's of these techniques respectively?


texts: If I insert a new gene with a yeast integrating plasmid and select with a drop out culture once, can I assume that the newly integrated gene will stay in the strain without putting selective pressure on it?  (i.e. can i use normal liquid culture and plates after getting the yeast with the newly integrated strain?


texts: Tools that take a kinship matrix for phylogenetic decorrelation

texts:
I have plant genotypes that have been classified as Invasive, Wild or Domestic. I am trying to investigate what explanatory variables (such as "leaf size", "width of petals" and other continuous variables) affect the probability of being classified a sone of the three groups. I therefore have to perform a multinomial logistic regression. However, I would like to account for phylogenetic non-independence using a kinship matrix.

Are there R tools that can perform such regression?

I considered lmekin for example but I don't think it manages to take a response that can take 3 different categories. Is there some function I would be interested in (in the ape package for example)?


texts: Why does higher venous volume increase atrial pressure?

texts: If the cardiac output stays the same (hypothetically, although obviously it doesn't stay the same), then why does higher venous volume increase right atrial pressure? Shouldn't the flow rate be conserved (with a constant cardiac output) so that the venous return to the right atrium is no different than before, and therefore the pressure is no different?


texts: Is it possible in modern biology to make any person's identical twin (or genetical clone) using his DNA?

texts:
I was told by a Biotech professor (who came in our college for a guest lecture) that Bio Technology has now become so advanced that if we want to make an identical twin (or Genetical DNA Twin) of a person then we can now be able to it using his DNA. I am a Mathematics Student so I don't know much about it. I just attended the lecture because I found it interesting. I am sorry, I know I should have asked this very simple question in Quora but, I wanted a precise answer which could be believed. So I asked here, where I will get answers only from the very experts. I apologize again Thank You So Much in advance

Edit 1 :- I am satisfied with @Remi.b 's answer, @Bryan 's explanation and @anongoodnurse ' references. I should also have mentioned genetical DNA Clone in the place of identical twin. Now I've added.


texts:
These guys are infesting my place. I searched through this site and came to know that they are cloth moths. All these days I used to see the left one type in the image. Recently I started to get the ones looking like the right ones.

As you can see the the right ones have a black border like thing at the end of the casing which the other kind does not have. Also , it looks like it has a different kind of structure from the left one, no ? I don't know..
So, are they the same ones or different kinds ?


texts:
There is a (VIDEO) on Facebook where the fish starts to flail around despite no heart or internal organs.

What causes the fish to flail around the way it does?

My theories:

It is because of pressure causing the muscles to contract - much like when you leave your own hand loose and squeeze up your arm making your fingers curl.
It is because the nerves are still alive - much like how you can rub the fish heart the right way and cause it to beat again even though the fish is very much dead. (I watched my fifth-grade teacher do this in class)


texts: Organism-specific Kegg Pathway: Must all boxes be high-lighted/present for a reaction to occur?

texts:
I'm new to using Kegg and not sure how to interpret the position of the pathway enzymes in the pathway that I'm looking at. More specifically: If all boxes (of KOs) must be present/colored green or not for a reaction to occur.

I'm looking at this pathway: http://www.kegg.jp/kegg-bin/show_pathway?ooe00010

Looking at the 'help' for Kegg indicates that the KOs represent a protein complex, because the boxes are 'stacked' against each other. Is this correct?

Specific reactions that I've been looking at: alpha-D-glucose-6P to beta-D-glucose-6P (One box is there, the other is missing).
Or the route from Glyceraldehyde-3P to pyruvate. I'm thinking that these pathways must be present, but in the very first reaction only 1 of 2 boxes are colored. I suppose it's also a possibility that Kegg's database is simply incomplete?


texts: Large black caterpillar, cocoon, moth - Los Angeles

texts:
This is my first visit here, probably the first of many, since I have many species to identify!

The first is a regular resident of my back yard in the Los Angeles neighborhood of Mt. Washington. It's a large black caterpillar that comes out at night to feed on what I assume is native flora. I have seen as many as five or six at a time in a good (wet) year, but the last couple of years have literally seen only one at a time. Note the ant in the lower left for scale:

A couple of years ago, I brought one home and kept it in a terrarium until it pupated and hatched.  I have a picture of the cocoon, but can't post more than 2 links right now. It was dark brownish-red, with strands of silk that looked to anchor it to the ground, with the empty body on top.

It turned into this very pretty moth:

Unfortunately, it beat up its wings a little, as it took me some time to realize it had hatched. It was released at night.

I had a possible ID at one point on another website, but I didn't follow up with them, and have a lot of trouble searching there for my old thread. Found this place, and thought I'd give it a shot. As I say, I have many more species questions, but I'll just start with this one. Many thanks in advance.


texts: Is it possible to estimate how much variation in common phenotypes is predicted by genetics?

texts:
Phenotypes such as; skin color, eye color, nose shape, lip size, limb proportions, and skull shape.

Im trying to find a source for this quote.

"If you ask what percentage of your genes is reflected in your external appearance, the basis by which we talk about race, the answer seems to be in the range of .01 percent," said Dr.

Harold P. Freeman" From - http://astro.temple.edu/~ruby/opp/racesnyt.html


texts: Examples of creating a new animal species by humans

texts:
So recently, I was arguing with my friend who happens to be creationist. As he does not believe in the "theory of evolution" I asked him how he can explain such a big diversity in the dog Canis familiaris sppecies. (The example taken from Charles Darwin's on the Origin of Species saying that humans made to dogs what mother nature has done to every species)

My friend replied something like:

  Well, having chihuahuas or huskies is one thing but, getting a tetrapod from a fish is a something which can never happen.

I realized that indeed the Darwin's example isn't perfect... Even though, due to size chihuahuas and hounds can't copulate efficiently their semens and ovaries can start a new life.

I can't give a counterexample of a species which was bred artificially by human for so long in a new direction that a new species (whose specimens by definition were not able to reproduce with the specimens of the base species) was created.

It's not that I am becoming creationist... but is there any exception from that rule for any artificially bred animal species?

[Edit]
This question has nothing to do with this
I am strictly asking about examples of an artificially bred animal species which got bred into two species.

[Edit 2]
Also to be exact, I am not interesed in specimens that can't reproduce due to various "external" circumstances like environment's temperature or size (chihuahuas&hound example). I am interested in specimens which come from the same base species and can't reproduce even with the help of in vitro fertilization (I know this is not exactly the definition of species). I just want to avoid getting answer similar to this.


texts: Mitosis versus Meiosis I: What's the difference?

texts: At the end of mitosis, one cell has divided into two diploid cells. But at the end of meiosis I, there are two haploid cells. How are the two processes different to produce these two types of cells?


texts:
Magnetoreception is a sense which allows an animal to detect the Earth’s magnetic field in order to perceive direction, altitude, or location. Magnetoreception is present in bacteria, arthropods, molluscs and members of all major taxonomic groups of vertebrates.

  There are several hypotheses that magnetoreception could occur in humans due to cryptochromes, which are a class of blue light-sensitive flavoproteins, because they have been observed to detect magnetic fields in a number of species.

Furthermore, I read somewhere that magnetic bones exist in the human nose, specifically in the ethmoid sinuses. $^1$

Is there more research on those "Magnetic bones", and to what extent is magnetoreception possible in human-beings?

$^1$nature.com/nature/journal/v301/n5895/abs/301078a0.html


texts: Can something cause both breaks and cross-links in DNA?

texts:
A double strand break in DNA is exactly that: the strands of DNA are severed. A cross-linkage occurs when something forms a covalent bond between two nucleotides in DNA. However, is it possible for something to form both a cross-linkage and a double-strand (or single-strand) break? For instance, could one part of a molecule cause a break while another reacts to form a cross-linkage?

For the purposes of this question, enzymes or proteins which do this (If there are any) also count.


texts: My mother found a hornet at home (in northern France) that is probably building a nest. Is that an asian hornet? If yes, how can I exterminate them?


texts: Mode of Enzymatic Inhibition via R-Allele

texts:
The photo above shows the effects of the R allele of the pea shape gene on the synthesis of an enzyme that converts unbranched starch into branched starch. The r allele of this gene determines an inactive form of the enzyme, leading to a buildup of linear, unbranched starch that ultimately causes seed wrinkling. My question is, How does the r allele specifically prohibit the activity of the enzyme?

Does the DNA/Gene sequence simply code for proteins that create an enzyme which cannot bind to its respective substrate ?
Is the substrate in the above illustration the unbranched starch itself ?


texts:
Cleaner fish are those fish that eat the dead skin cells and parasites off from other usually larger fish.
( such cleaners include wrasse, cichlids, catfish, shrimp etc )

I wondered if the cleaner fish themselves ever receive this service from others, though understandably it is an added benefit rather than a necessary one for health.


texts: What percentage of protein isoforms have different functions?

texts:
I am looking for studies on how many protein isoforms have different functions, preferably in human. We know that a great many, if not most, of human genes are alternatively spliced and that many produce different protein isoforms. Has anyone looked at how many of these isoforms have different cellular functions? If someone could point me to a published paper, that would be great.

If no such study has been made, can anyone recommend a database from which this information could be extracted? GeneOntology is gene based so the information cannot be found there. Genes will be annotated to specific terms, not their protein isoforms. Also, I would need to be able to do this in a high throughput manner, I am not interested in specific proteins but in what percentage of all isoforms have different functions.

Ideally, I would like to be able to extract, for every human gene, the list of the different protein isoforms it encodes and whether their functions differ, or at least what those functions are.


texts: If I have alleles AB on one chromosome and ab on another, and if A and B are far from each other (and also a and b), then there is a lot of chromosomal crossovers happening. If I crossover 7 times, will I end up with the same chromosomes as if I cross over once?


texts:
Opening the cupboard I am shocked to find it full of these insects inside. Haven't found them anywhere else. At first, I thought it was ticks, but not so sure. Plan on cleaning out the cupboard and using Bifen I/T to hopefully kill them.

I live in the Caribbean and would like to identify and find out how to get rid of them.


texts: What did the ancestors of textile moths eat?

texts:
These days I had to wrestle a lot with textile moths. From the Internet I got the impression that these moths don’t feed on naturally available furs in the wild, but have specialised on man made textiles(?). From the Wikipedia entry on textiles I gather humans started wearing textiles (not furs) about 6500 years ago.

Did the ancestors of textile moths (from the time of textile adoption) feed on furs and such, or were they akin to today’s kitchen moths, which eat food stuffs?

In the latter case, is not 8500 years a very small time for such a fundamental change in animal biology? Or must I take into account the short lifespan of insects, equating each human year to a dozen generations and each human generation to about 300 moth generations, so that the change moths can undergo in 6500 years is more akin to that humans can undergo in 250.000 years (which perhaps has to be increased even further due to moth simplicity and large population making non lethal mutation more common) ? For comparison, it appears Homo  Sapiens emerged some 200.000 years ago.


texts: What is the average membrane potential for a neuron?

texts: I'm familiar with the resting membrane potential and other relevant values, but I wondered if there was any research done on the average subthreshold potential of a neuronal membrane over time.


texts: Is the glucose produced from photosynthesis considered an aqueous solution when written as a chemical reaction?

texts:
In the very simplified reaction for photosynthesis, the states of the reactants and products are clear to me except for glucose. Inside a plant, it would be dissolved in water, so would it be an aqueous solution or be considered a precipitate in some way? In the reaction

$$\ce{6CO_2 {_{(g)}} + 6H_2O{_{(l)}} \rightarrow C_6H_{12}O_6{_{(?)}} + 6O_2{_{(g)}}}$$

what would I put in the place of the question mark?


texts: What are typical values for bone mass in humans?

texts: I wonder what are typical bone mass values for adult males and females? And do they change significantly with workout and diet?


texts: Is there a correlation between incidence of type 1 diabetes and vitiligo?

texts: Does the data indicate that if you have one, the probability of you having the other is higher than that of someone who doesn't have the one?


texts: Why does the HLA show a high degree of polymorphism?

texts: I know how the HLA undergoes high degree of polymorphism (random genetic rearrangements), but I have not understood why it undergoes rearrangements. What is the advantage offered when HLA shows a high degree of polymorphism? What would have happen if all individuals had the same HLA?


texts: How are viruses weakened to be suitable for vaccination?

texts:
I understand there are two kinds of active vaccination

Injecting complete viruses that are weakened to not cause the disease being vaccinated against
Injecting only antigen particles of viruses that the body creates antibodies for. So the disease can't arise, not even in a weakened form.

I am wondering how the viruses for vaccination are weakened. Is this simply a process where randomly parts of the virus DNA/RNA are taken out and tested on animals, and as soon as it is sufficiently weakened, it is considered suitable? Or is this an analytical and systematic process?

I am wondering because some popular vaccinations (including that against measles) can still (very rarely) cause fatal complications. Which made me think whether it's systematic or just "accelerated mutation and selection".

I'm interested in an answer for layman, if that is possible at all.


texts: Evolution: One big population vs. many small populations

texts:
Let's say I want to evolve a bacterium that is resistant to an antibiotic. I want to do this by growing initially clonal populations of bacteria in presence of this antibiotic for a long time.

I have two options:

Make one 50 ml flask culture
Make ten 5 ml tube cultures

What are the comparative advantages and disadvantages of these two? Clearly, the ten culture version is better at probing the space of all possible resistance mechanisms. However, what about the rate of evolution? If I just want to get a resistant strain as fast as possible, which one should I use?

Note that "antibiotic" is just a proxy for any selective pressure, and "bacteria" is proxy for any organism. If possible, I think it will be interesting to address the effects of sexual vs. asexual reproduction in the organism that is being evolved.

There is already a question, How does rate of evolution/innovation scale with population size? that is very similar. I think mine is different, because it is not one small population vs. one big population, but one big population vs. many small populations. In other words, I am attempting to control for number of selection/mutation events, and focus only on the stratification of the total population.


texts: Are there any DNA base sequences that are shared by every living being that we know of? And if yes, are some of those sequences "silent"?

texts:
In "every living being" I am not including viruses as another question already answered that.

I have read that some part of the DNA sequences of humans and other animals/plants are "silent" as in not affecting the phenotype of a species.

I was wondering if there was some part of those silent sequences that are also common to all living being.


texts:
While normal jellyfish don't have any eyes, box jellyfish have 24 eyes.
Looking into my question on the internet, in one answer on Quora to the question Do jellyfish have eyes?, it is said that:

While box jellyfish have eyes, they cannot process images at all because they simply don't have the central nervous system to process images [Source: GRE Biology question I got right].

I heard somewhere though that box jellyfish do have a nervous system and they can see with their eyes.
I have found answers on Quora to be a bit hit and miss with their accuracy and wondered what the facts are.


texts:
I'm trying to find out what kind of spider is this little fellow:

It really seems to like our garage and is the bane of my girlfriend (as evidenced by all the screaming when on two occasions one got into our home somehow). I was never able to spot this kind outdoors, which is rather odd (there are plenty of Araneus diadematus spiders in the area which are fairly easy to spot).

It's hard to tell on the photo, but these spiders seem rather big (at least as far as spiders in Poland I was able to spot go)... somewhere around 5cm at least (legs included)? They really do make for rather large, black spots against an otherwise white garage wall.

I'd really like to find what kind of species this is so that I can, hopefully, convince my GF that it's harmless to humans. Unless it isn't, in which case I'll start getting scared of walking into our garage. ;)

PS. We live in Poland, Poznań.


texts: Do we come to know which allele is dominant by seeing family genration tree only?

texts:
I know that a Gene has Alleles (variation) and one is Dominant over Other i.e the Other Recessive.
Then I got a Thought that How can we tell whether an Allele is Dominant or Recessive...... and I came across this Site while Googling, and It says we can tell this by Observing Patterns in the Family Generation Tree.
So, my question is that can we only describe an Allele by observing pattern? Is there any other Method or by looking at the Molecular level and tell?
Please extend this "How can we tell whether an Allele is Dominant" to a Special Case where a Gene has 3 Alleles.....can we have 2 Dominant Allele?


texts: After mRNA is released from the nucleus, the next process is its translation by ribosomes. By what physical, chemical or biochemical process does the mRNA reach the ribosome in the cytoplasm?


texts: Why does solute potential go up as temperatures go down?

texts:
So the closer a solution's solute potential is to zero, the more water potential said solution would eventually have. The solute potential equation is -iCRT. If the temperature is 0, -iCRT would be equal to zero, and because temperature is measured in Kelvin, this would mean the solution is at absolute zero. Things can't move at absolute zero. How is it that that water has the most potential to move at absolute zero?

Same with the opposite.

If the temperature is high, wouldn't that mean water potential would be at its highest because water molecules are at high energy, jumping around everywhere?


texts: What is this insect found commonly in coastal India?

texts:
I have lived in two cities on the western coast of India and I have seen quite a few of these insects(?) in both places.

It basically has an outer cocoon of sorts, which looks a lot like dirty lint. The actual insect is a small wormlike creature at the top of the cocoon. It almost always tries to keep climbing up walls and when it dies, it remains stuck to the wall from its topmost point. The overall length of it, including the linty cocoon is about half a centimeter.
Can someone tell me what these are and if I need to actively avoid them or prevent their appearance in my closet?


texts: Are oxygen and carbon dioxide simultaneously present in red blood cells during gas exchange?

texts:
From my understanding, the process that displaces the carbon dioxide and oxygen in our erythrocytes and lungs is diffusion. I've been taught that diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration, until an equillibrium is reached.

For there to be an equillibrium in carbon dioxide and oxygen, doesn't that mean that there should be equal portions of those elements present at all times? So therefore, erythrocytes should contain both of those chemicals simultaneously. Am I correct in assuming this? If I am, then I have a follow-up question: wouldn't carbon dioxide floating about in our blood indefinitely cause some unhealthy side effects, and is there something that prevents it from doing so?

I'm currently only in GCSEs, so apologies if this question might actually have a very simple answer.

Thanks


texts:
The shortest path problem is the problem of finding the shortest path between multiple nodes. What are the applications of the shortest path problem in biology?

A simple google search gives me this - http://mutage.oxfordjournals.org/content/30/2/191.full.pdf
This, unfortunately is under a paywall.

Apart from that article, I can't find anything else useful.


texts: Can bacteria metabolize fatty acids for fuel?

texts:
I'm not a microbiologist, but rather a physiologist  curious about microbial metabolism. Much like humans bacteria can utilize glucose, but when it comes to long chain, medium chain, or short chain fatty acids, what are the pathways that microbes use to break these compounds down for fuel?

It seems plausible that bacteria can take up short chain fatty acids, but with longer chain species are there impediments to uptake? Are the oxidative enzymes similar between bacteria and humans?


texts: Why Is Most Life Symmetrical Externally But Not Internally?

texts:
Mammals, reptiles, arachnids, insects, etc are all as far as I am aware symmetrical in appearance.

Take a human for instance, make a line from the top of our head right down the middle. However, internally it is not the same. Our organs excluding the kidneys, lungs, reproductive organs, etc are not symmetrically placed in our body.

Why do we not have an even number of each organ so it can be placed symmetrically?
If we have a single organ why is it not placed in the middle like the brain or bladder is for instance?
Is there some evolutionary advantage that led to this setup?


texts: Why do hand/fore-arm muscles "lock up" after very high-powered effort?

texts:
Inspired from Why does it hurt the next day after doing significant exercise? with its excellent answer:

In climbing, you can put tremendous load on the hand/fore-arm muscles (specifically, flexor pollicus longus and flexor digitorum profundus). What happens is often that you are not just fatigued, but that the muscles seem to "lock up" - they subjectively feel "hard", it seems impossible to relax and the problem does not go away after a few minutes, by stretching (which will actually become quite painful) or by self-massage.

The muscles are not necessarily showing the burning sensation that indicates lactate buildup according to the answer for the linked question. This effect seems to be a main cause for athletes to prematurely end a training session because there's little hope to solve it except for a long (hours...) rest. People have trouble opening doors etc. because the muscles seem to be completely wasted. Onset is immediate during or after a straining exercise, not later, like DOMS would be. After a good nights sleep, the problem usually seems to go away, it is not a day-long soreness.

Is that effect rather related to damage (micro tears etc.) or some chemical process? Is there a good way to prevent it, either in the short or long term, i.e. by training specifically for/against it? Are you aware of other muscles that show the same behaviour? I have only experienced it in those.


texts: Please identify this moth from Bangladesh

texts: Sorry for bad resolution of the picture. This picture is taken from JU campus, Savar.


texts: Does cellular/organism death happen to enable evolution?

texts:
On the topic of whether we could conceivably understand death and extend human lifespans significantly - I'm wondering if any smart folks can point me to where my thinking regarding death may be wonky.

Hypothesis: Death only exists as an evolutionary advantage, and decoding the genome would point to designed cell death

Offspring provide a chance for mutations and evolution. Bacteria, with their short doubling time, can evolve very quickly (e.g. antibiotic resistance). Humans, with a longer lifespan, cannot evolve as quickly.
While the exact metric above is not linked to lifespan directly (its actually reproductive rate), I'd argue that at stable/equilibrium population size (due to resource constraints) they are indirectly correlated.

Understandably, there are many factors that introduce mutation into a species, other than death rate. Some species may have more powerful DNA editing enzyme variants that lower mutation rates.

Some counter arguments may include 'wear and tear', the notion that no organism can live forever as any ordered matter tends to break down over time. Some cold-water fish have low metabolism rates and long lifespans.

What can I learn about this topic?


texts: Enzyme with long tube leading to active site?

texts: Are there any enzymes that force one or more of their substrates to travel a relatively long distance through a small opening/tube through the enzyme and  to the active site? (not a transport protein)


texts: Does too much screen time really damage your brain?

texts:
So I was looking on the internet for articles to whether computers really damage your brain and I found that half of them say the do and the other half say the don't. Personally I don't think it does as majority of working people use computers in their day to day jobs and still have the same intelligence and cognitive ability after say, 10 or 15 years of using them.
So does anyone know wheter this sttement is true or not.
Thanks,
Ps. I'm not a biologist, I'm just a curious kid :)


texts: Case study and speculations on the brain of Edward Mordake

texts:
I am very interested in the case of the man named Edward Mordake who lived in the 19th century. In particular, he had two faces. If you have not heard of this man, please, search this up as there are a very few amount of photos, but it is something very, very strange.

However, all the information on him seems to be speculation, so I am looking for a scientific look at this. I am unsure if it will even be possible seeing as how the years have passed and records may not have been accurate.

To be specific, has this condition been noted before? There seems to possibly be differing opinions onto wether the face was indeed its own individual inside, or a low functioning other half of the same man.

Indeed I am looking for any info on the biology of his brain, possibly the neuroscience and or physiology, and of course any comments and discussion.

Thank you


texts: Trying to understand a scientific text about neurons and dopamine

texts:
I'm in the process of reading https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1564381/ and I'm trying to understand how the predicting is done in the neuron.

What I distilled so far: A cell gets an input, it calculates a probability of reward(bliss potential i like to call it), if it could cause a reward it releases dopamine in a quantity of expected reward.

So right now I'm wondering,  what is the process that goes on to make that calculation. Which input variables does the neuron use to calculate the probability of a reward and how much dopamined to release?

Does it take account which synapses provided the input signals? Or is it the type of input signals? Or a combination of both? Is it the frequency inputs occur?

II need an explaination how the neuron calculates its "bliss potential" as i like to call it, in normal peoples english instead of academia english.

P.s. I don't have an academic background.  I'm just interested in science related things without having a formal education.


texts: Optimal carbon dioxide concentration range for the human body

texts:
Previously I had thought the maximum concentration of  CO2 for human health to be given by the ‘Pettenkofer CO2 level’ with a maximum of 1000 ppm.

But according to this post

  a growing body of research suggests CO2 levels as low as 1,000 ppm
  could cause health problems, even if exposure only lasts for a few
  hours.

Therefore it looks like a lower value than 1000 ppm would be healthier for the human body. Is that so?

What would be the target CO2 level inside a passive house? Since outside it is in the range 3-400 ppm. So with more ventillation we could get closer to 3-400ppm, which is Nature’s default (which shouldn’t be bad?)

Perhaps 750 ppm would be ideal — is there any research on that, either cognitive or related to blood vessels.


texts: When there's a wound, the end result is a thrombus or thrombosis?

texts:
When there's a wound, the blood vessels are damaged. To stop the loss of blood, the clotting cascade starts off and forms a clot. This clot is a thrombus, right? Seems like perfect physiology. Where does the clot occur? As in, if we consider the vessel to be a pipe, the clot is formed at one end to block the flow or is attached to the wall of the vessel on one side?

This doubt arises because thrombosis (considered pathological) is defined as a clot within a blood vessel. Is the same not happening when there is an injury? If we consider the clot formed at one side of the vessel wall, doesn't it become thrombosis? Even if the clot is like a plug, it has to be attached to the wall, right?

In short, what is the difference between a clot due to a wound and one thrombosis (due to the Virchow's triad)? Where are the clots attached in either cases?


texts: Why do you need the intrinsic pathway when you have faster extrinsic pathway?

texts:
There are two pathways in blood clot fromation; the extrinsic pathway and the intrinsic pathway.

The extrinsic pathway is faster than intrinsic pathway because it has less number of steps. So, why do we need intrinsic pathway then?


texts: If people can survive being frozen some, why not indefinitely?

texts:
I've heard of cases and also personally met someone who survived with a full recovery after they were taken to the hospital after being found unconscious in the snow for (presumably) more than 45 minutes, and claimed their temperature dropped below 0 degrees (Celsius) after they recovered in the hospital, though obviously I can't go into their medical records and verify that temperature. What mechanism allows someone to survive being so cold for so long, particularly if there is a lack of oxygen to the brain, and if someone can survive it for that long, why not indefinitely like for cryogenics?

I'm no medical expert by any means, so it's possible it's a combination of things of course, but for references the first being that a doctor telling me first hand that it's possible, but rare for someone's pulse to stop in frigid temperatures and still recover after more than 10 minutes with a lack of oxygen referencing something about the decomposition of tissue slowing down, and then also news articles like these that I don't have any particular reason to doubt given the consistency of such a story across different venues, which also suggest something about frigid temperatures allowing people to survive injuries, oxygen deficiency, or tissue damage for a longer than normal time.

I'm not completely sure about the lack of oxygen part of the question because it kind of seems like they evaded that part of the question, but they definitely said frigid temperatures delay the decomposition of tissues in someone's body and suggested someone could survive longer due to that, and I don't know why tissue decomposition would be a problem unless someone had already lacked oxygen for a long time to make them susceptible to it.

https://news.google.com/newspapers?nid=1876&dat=19810109&id=CkosAAAAIBAJ&sjid=uc0EAAAAIBAJ&pg=6891,1583308&hl=en

https://en.wikipedia.org/wiki/Jean_Hilliard

http://www.nytimes.com/1981/01/03/us/dakota-teen-ager-recovers-after-being-frozen-stiff.html

http://abcnews.go.com/Health/hypothermia-save-boy-trapped-ice-30-minutes-heartbeat/story?id=9506900

http://www.dailymail.co.uk/news/article-3406926/Man-presumed-dead-frozen-solid-road-recovers-living-medical-miracle.html

https://en.wikipedia.org/wiki/Anna_B%C3%A5genholm

I remember the old saying "better cold and dead than warm and dead," I guess this makes sense for when you find someone unconscious.


texts: Can Naegleria fowleri enter through your ear?

texts: Is it possible to get infected with the amoeba, Naegleria fowleri, through your ears, or is the nose the only way it can enter to cause infection? How commonly is it found in your stool as well?


texts: Is marriage with half-cousin's daughter more risky than marriage with others?

texts:
I want to know is marriage with half-cousin's girl more risky than marriage with a non-family girl?

Also I like to know if her parent are cousins(but from mother side), does it add more risk to this marriage or not?


texts: Do babies have a fight or flight response?

texts:
Do babies react in the same way as young children and adults in regards to the fight or flight response? If they do not respond in a similar way or don't have a fight or flight response at all then at what age is this developed. My teacher said that babies don't have a fight or flight response and we are unsure of when this develops but I'd like more information if there is any.
Thank you!!


texts:
Can someone identify this plant? It was growing under my 2 year old's climbing wall / play house thing. I live in West Virginia, USA and it's currently June 3rd (if that helps from a climate standpoint).

I know there are some potentially dangerous invasive plants like the giant hogweed. I hope someone here can help me identify this and give me any tips on what to do about it if it is in fact hogweed.


texts: Derivation of Michaelis-Menten kinetics for discrete stochastic simulations

texts:
According to this article,

  [...] the propensity function for the conversion reaction S → P in the
  well-mixed discrete stochastic case can be written $a(S) = \frac{V_{max}\cdot S}{K_m + S/\Omega}$ where $\Omega$ is the system volume.

I don't quite understand how this formula is derived from the non-discrete Michaelis-Menten kinetics $v = \frac{V_{max} \cdot [S]}{K_M + [S]}$ (see Wikipedia). According to my understanding, $[S] = S/\Omega$. If we apply this to the formula from Wikipedia we get
$$
\frac{V_{max} \cdot[S]}{K_M + [S]} = \frac{V_{max} \cdot S/\Omega}{K_M + S/\Omega} = \frac{V_{max} \cdot S}{\Omega \cdot K_M + S}
$$
which is not the same as $\frac{V_{max}\cdot S}{K_m + S/\Omega}$. So, how can one derive the formula from the quoted article (if it is correct)? If not, how can we correctly get to a discrete propensity function from the Michaelis-Menten kinetics?


texts: databases for plant growth temperature and altitude

texts: Does anyone know databases which have info for plant growth temperature.It could be specific numbers or categorization as 'cold, warm,tropical and etc' ?


texts: I am only 15 years old,and my primary school education hasn't been that good,also I forgot a lot of things. I would like to start again,and I am asking for your advice. What are some of the good websites/books/methods that can help me?


texts: How late in a human pregnancy can a zygote split?

texts:
This page indicates that the first two days is "very early" for a zygote to split, and that conjoined twins are the result of an "extremely late" split:

  If the zygote splits very early (in the first 2 days after fertilization) they may develop separate placentas (chorion) and separate sacs (amnion). ... Most of the time in identical twins the zygote will split after 2 days, resulting in a shared placenta, but two separate sacs. ... Finally, the zygote may split extremely late, resulting in conjoined twins.

What I'm looking for is more specificity. At what time in the pregnancy does a split zygote result in twins who share a placenta and not a sac? What about conjoined twins (I'm most interested in the most common types of conjoined twins)?


texts:
Congenital Nystagmus is an eye focusing disorder. It happens in manuals. Wikipedia lists several treatments on its page. Are any of those FDA approved for human use of that disease.

  drugs found to be effective against nystagmus in some patients include memantine, levetiracetam, 3,4-diaminopyridine, 4-aminopyridine, and acetazolamide.
  -wiki


texts: Electrocardiogram: Difference between Atrial Fibrillation and Atrial Flutter

texts:
I have been working on analyzing Electrocardiogram data.

I have read several documents related to conditions of the Atria during fibrillation and flutter, the most lucid being that atria quiver with rapid rate.

This manifests as multiple P-waves (some documentation refers to them as "F-waves" and regards P-waves as absent) in the Electrocardiogram.
However in this condition, we get a completed QRS-complex in the Electrocardiogram.

Now, coming to my question, in both scenarios i.e. Atrial Flutter and Atrial Fibrillation, i get multiple P-waves(or F-waves) with completed QRS.
So how do i differentiate between the two conditions ??


texts:
In particular, how did the close cooperation of its many component species evolve?

My hypothesis is that it began with a few, probably no more than two zooids cooperating in symbiosis, and overtime, either entirely new species of zooid adapted to first parasitize and then cooperate with the existing company, or that some of the existing zooids mutated to acquire different functions. As the new zooids join the cooperation, the other re-adapt to form the "species" we see today.

Is that a somewhat accurate description of the evolutionary history of this colonial organism?

Addendum:
Would the relative simplicity of the polyps forming the colony be a crucial prerequisite in their cooperation and specialization?


texts: After fat is burned from one part of the body, is fat moved around the body?

texts: If you go running, for example, and burn fat from your legs, does your body send fat from other parts of the body to that area? If so, why would it do this?


texts: While someone's ears pops with pressure, can he/she hear other sound at the same time?

texts: I know that after or before someone's ears pops because of pressure changes, he/she can hear the sound such as laughter. But can these two things ("her ears popped with pressure" and "she can hear the laughter") happen at the same time?


texts: What are the most common mechanisms motivating mammals to mate?

texts:
I read somewhere that dolphins and humans are some of the only species known to have sex for fun. I was just curious

What motivates mammals to mate? (Like what compels them to do it, not what the purpose of doing it is)
Are those motives solely aligned for reproduction or are there other benefits to mating?


texts: How does one go from a couple of DNA sequences to a distance-matrix?

texts:
For a project we need to explain the subject of UPGMA.
We think we understand thee method itself but I fail to see how you go from a number of DNA-sequences to the distance matrix.

I understand that the lower the number, the more related two species but on what scale is this number and how to interpret the exact meaning of this number.
For example if the number between A and B is 17 what does that mean?


texts: Can sugar alcohols, and glycerol in particular, cause intoxication?

texts:
I'm mostly curious about glycerol, which I use as a sweetener. I've been told that it can cause intoxication, because it is an alcohol. Is this true?

If so, are there any good sugar alcohols which can be used safely without intoxication (or nasty side effects)?


texts:
In a recent TV documentary it was said that a particular tree root could grow miles long. However, I forgot the name of the tree and I don't remember the name of the TV program as well.

I searched on the internet but I could not get it. Does any one know about this tree and how tall its roots can grow?


texts: Can flow cytometric analysis differentiate between a parent contributing longer chromosomes versus multiple smaller chromosomes?

texts:
For flowering plants, can flow cytometry of seed from muti-generational interaction of two species and their offspring help us decide if wide differences in genome size for the two species and their offspring is a function of differences in chromosome count versus chromosome length?

Flow cytometry of seed allows us to examine the contributions by the 2 parents to the resulting offspring from generation to generation.

The basic premise is flow cytometry scores for the offspring of "triploid" intermediates would distribute differently if the issue was length versus count. Fine distribution would indicate "aneuploids" because of counts whereas wide distribution would indicate length because length differences are concentrated in only a few chromosomes.

This basic premise proved faulty since flow cytometry scores indicate fine distribution (genome size scores reflecting every potential aneuploid between triploid and tetraploid) but documented chromosome counts indicate the issue is length.

What are the normal distribution patterns in terms of genome size for multigenerational offspring between 2 species having wide differences in chromosome length?

.


texts: distribution of some injected materials/medicines through blood vessels

texts: Fastest distribution of some injected materials/medicines & with no risk of any kind can be achieved by injecting it into - artery or vein?


texts:
I'm reading in a paper in which the authors have made three cell lines to study the function of a gene of interest (Mbd3):

The one is knocked out for the gene of interest [Mbd3 -/-], the other is floxed for the one allele [Mbd3 fl/-], and the third is rescued knock out cell line [Mbd3 -/- (rescued)], that means that in the cell line of knocked out cells they have stably transfected a plasmid expressing the gene of interest. I am then wondering, why they use this rescue cell line, instead of using the wild type cells with the wildtype alleles of Mdb3?


texts: The concept of high genetic load of disease and non-random segregation of deleterious variants

texts:
I'm new in this field. I was reading Shakeel et al. (2018) and came across the below sentences

  The rate of emergence and distribution of deleterious variants in populations is important in determining the patterns of underlying genetic load for diseases, because the increased accumulation of genetic load of diseases due to non-random segregation of deleterious variants is so detrimental that fixation or near fixation of these mutations can play a significant role in the extinction of isolate populations with small effective population size.

I'm not sure to correctly understand the concept of the sentences, especially

  genetic load of disease and its accumulation due to non-random segregation of deleterious variants.

Could you please kindly explain a bit to me about it?

Many thanks in advance


texts: Transformation of a multicellular organism

texts:
I was reading about using RNA-interference as a method of introducing pest-resistance in plants. In tobacco plants, using Agrobacterium vectors, genes specific to the nematode Meloidegyne incognitia were introduced. This was done in such a way that it produced both sense and anti-sense RNA in the host cell, forming dsRNA and ultimately silencing specific mRNA of the nematodes.

My question is, how can every single cell, or a proportion of cells sufficiently large so as to confer pest-resistance, of an already mature plant be transformed? Are a large number of vectors introduced, and as the infection gradually progresses, the immunity spreads throughout? Sorry if it's a stupid question, I've been out of touch with biology for a while.


texts: How far can we go in engineering our own evolution?

texts:
After recently seeing Christopher Nolan's Interstellar and reading Kip Thorne's The Science of Interstellar, I've seriously been reflecting on the challenges mankind faces in becoming space pioneers, which in my belief will be a necessity to survive as a species. Not just the technological challenges, but the biological ones as well.

Technology can only go so far to aid and protect an organism against the brutal environment of space travel. And so the day may come where we have to make a choice on engineering our own evolution to become a hardier species that can better cope with that environment. The two immediate attributes that come to mind are resistance to radiation and extended life spans.

And this brings me to my question. Putting aside for the time being the question Should we make this choice ?, my question is How far could we go towards engineering a space-durable human species?


texts: If there is such known "Mitochondrial Eve", does it means that all the mitochondrial dna in everyone's body is same?

texts: P.S. I know not that much, just some basics, but this question really interested me :)


texts: Measure Water-Use Efficiency without using carbon isotope fractionation?

texts: I read "Measurements of delta (C-13) in C3 species may usefully contribute to the selection for transpiration efficiency." I think the device to measure carbon isotope fractionation is very expensive. Are there some easier ways to measure the water-use efficiency of plants, please? Thank you.


texts: The most reliable way of identifying deer antler measurements?

texts:
I am creating a (theoretical) study on how males use antlers to assess fellow males' abilities. I thus would need to have accurate measurements of antlers, including length, width, number of tines etc.

The papers I am reading are either really vague, using data already available, or they are relying on antlers which are cast each year to obtain the measurements. In a real life study, the last would be least intrusive and the most ethical, but would it be the most reliable?

I am equally unsure of the efficacy of waiting for deer to cast their antlers to then obtain measurements, as well as having the issue of changes / potential misidentification. I could take the DNA from the antler and use that to identify the deer that they came from.

Does anyone have any experience of this / any input as to what would be the most ethical, reliable method of doing this?

I understand there are confounding factors in this study, with other traits likely affecting deer fights. They seem to be largely un-dealt with in the literature, and I am giving them thought also.
With thanks.


texts: Under what conditions do dendritic spines form?

texts:
I'm looking for resources or any information about the formation of dendritic spines and synaptogenesis, especially in relation to how new connections are formed on a daily basis.

Does the electrotonic signalling along the axons and through the spines cause new connections to be made based on some kind of spatial condition (maybe an electrical or chemical attraction), or is there some larger heuristic here?


texts: Why do high cholesterol levels result in a buildup of fat in blood vessels?

texts:
As is well known, high levels of cholesterol can lead to a buildup of fat in blood vessels, which can lead to them being constricted which makes it more difficult for blood to pass through. In fact, this can end up with the formation of fatty deposits that, if they suddenly break, could result in a clot that causes a heart attack/stroke. Therefore, the resulting buildup of fat because of these high cholesterol levels is highly important.

My question is why do higher levels of cholesterol result in a buildup of fat at all? Why do fatty acids care that there's more cholesterol around? I know cholesterol and fats are both lipids, but beyond that, I don't see the connection.


texts: What's the proton concentration around a DNA helix?

texts: Let's suppose the concentration of a 20-nt DNA strand is $10^{-4}$M and the solution does not contain any salt ions. In a solution with pH 7, $[H^+]=10^{-7}$M, on average each DNA has only 0.001 protons. But the DNA phosphate groups become charged through de-protonation so each DNA should effectively release 20 protons thus we would expect $[H^+]=20\times 10^{-4}$M. How does the system maintain chemical equilibrium while keeping charge neutrality? If $[H^+]=10^{-7}$M because pH=7, where do other protons go?


texts:
The fimbriae at the ovary end of Fallopian tubes are described as "sweeping" eggs from ovaries into the tubes:

When ovulation is about to occur, the sex hormones activate the fimbriae, causing them to swell with blood and hit the ovary in a gentle, sweeping motion. An oocyte is released from the ovary into the peritoneal cavity and the cilia of the fimbriae sweep the ovum into the Fallopian tube.

Is there more detail known about the "gentle, sweeping motion" of the fimbriae?  For example, is it a single swelling "sweep" per cycle?  Is the motion of the fimbriae against the ovary isolated from or accentuated by other movement of the body?


texts: Why does the kidney of a cow have lobules, why the kidney of a human hasn't any?

texts:
The kidney of a cow has lobules, while the kidney of a human hasn't any.

I can't think of any reason why it would be good for a kidney to have lobules. It would be good if the kidney needed to have a large surface area, but I don't see a reason why it would have to, since there is no diffusion or another proces that needs larger area.

Is there any reason why it would be beneficial for a kidney to have
lobules?
Is there a known reason why the kidney of a cow has lobules,
while the kidney of a human hasn't any?


texts: Do animals exist with an uneven total number of digits?

texts:
I recently finished reading Contact by Carl Sagan. In the book they talk about a pattern in the transcendental number like pi or e, and comment that it is found in base 10 or however many fingers the race has to count with.

When in the end they find a pattern in pi it is in base 11, which I found a strange choice since I can't think of an animal that has an uneven total number of fingers, and I would think that most evolution would result in a somewhat symmetrical design.

Do any animal exist that has an uneven total number of fingers or equal lim, excluding polydactyly and oligodactyly?


texts: Are there biochemical differences between the cell membranes of prokaryotes and eukaryotes?

texts:
I would like to know if there is any difference in chemical composition of cellular bilayer lipid membrane between eukaryotes and prokaryotes.

Specifically, I would like to know about the action of antimicrobial peptides on these bilayer membranes in context of the different membrane compositions.

It would be helpful if someone points me to some references.


texts: Is the protein in teardrops still attached to cells, or is it released and free-flowing?

texts:
A ScienceDaily article says that the protein in teardrops can kill bacteria.

But how does it reach the bacteria?


texts: How to identify a pseudogene to a specific protein coding genes?

texts:
Pseudogenes are those sequences in the genome that bear similarity to specific protein coding genes, but nevertheless are unable to produce functional proteins due to existence of frameshifts, prema- ture stop codons or other deleterious mutations (Mighell et al., 2000). While I doing some research on protein PLEKHA7, I use the PseudoPipe(an automated pseudogene identification pipeline)(Zhang et al.,2006) to find out the pseudogenes of PLEKHA7. But I am confused that the DNA sequence is 226929bps in length, its pseudogene is only about 100bps long but with a much higher identification like 41.1% and 71%. (chr = chromosomes,start = start position,end = end position,query =  parent protein,frac = fraction of the parent protein that is overlapping with the pseudogene,ins = number of insertions in the pseudogene sequence,del = number of deletions in the pseudogene sequence,shift = number of frame shifts in the pseudogene sequence compared to parent,stop = number of stop codons in the pseudogene sequence,expect = e-value for the sequence identity between parent and pseudogene,ident = sequence identity  between parent and pseudogene,polyA= presence of polyA signal,type = pseudogene biotype : PSSD =  processed, DUP =  duplicated, FRAG = ambiguous )
So how does these pseudogenes have such high identification to the parent gene as they are only very short sequences?


texts: Would a spinal injury decrease human height?

texts:
A woman I know has been losing height at a rate of few cm a year following a severe spinal injury. How is this possible? What kind of injury could cause such progressive loss of height? Could this be a genetic defect? Are there any disorders that cause this type of shrinking?

In case it could be relevant, her brothers are very tall.


texts: Why does dehydration lead to low blood pressure

texts:
I understand that the two leading causes of death from dehydration is imbalance in electrolytes and loss of blood pressure. I'm trying to understand what role water is playing in these cases and how the loss of it causes these imbalances, focusing for now on the blood pressure angle.

While I understand that blood is made up heavily of water, I'm still a little confused why dehydration so quickly leads to drop in blood pressure.  Why can't the body continue to pump the already existing blood through the body, where is it using the water to keep the blood pressure up and what vital function is no longer being performed that causes that pressure to drop?


texts: If humans can live without consuming other animals, then why do we do it? From a biological point of view, why do we eat meat? I would also extend the question to other animals because many animals are carnivorous: why did carnivory evolve and why do animals eat meat?


texts: Will someone with a double mutation in the allosomes be normal?

texts:
Normally a female human has an X allosome from her father and an X allosome form her mother. What if an double mutation happened, which causes that someone has two X allosomes form her mother and no allosomes form her father? Will this person be a normal female?

Note that it is both possible that there are no allosomes form the father or mother (known as Turners syndrome, (45, X)) and that there are two X allosomes form the mother (known as (47, XXX) and (47, XXY) respectively).

Since the Turner syndrome happens for 1 in 5000 births, and the Triple X syndrome happens for 1 in 1000 births, I estimate that this would happen once in 5 million births.


texts: Is there a possibility that medicine will affect the efficiency of natural selection?

texts:
I mean, saving sick people means that they possibly can propagate something that nature does not allow. I know that there is already something that operate at genetical level producing alteration, i.e. genetical mutation. And i am well aware that natural selection and genetical mutations take place really slowly.

p.s. i really want medicine to work!!


texts: Population-biology, migration-patterns, & ethology of the Big Five (elephants, rhinos, lions, leopards, & buffalo) in S. Africa's winter months?

texts:
I know that animals are unpredictable, but I also know that there are seasons in which the wildlife are more active. Now, August in South Africa is still their winter season, which is emerging into spring, and I was wondering what the population-biology, migration-patterns, and ethology of the Big Five (black rhinoceros, African elephant, water buffalo, African lion, African leopard) are like in August?

Now that's quite a variety of animals (some migrate, and others don't), but I'm essentially wondering: are the wildlife less active in August (because it's winter) or do they stay pretty active all-year round, even in the winter months (because of the warmer climate)? Are the migratory animals present in the winter time in Kruger National Park?


texts:
When species richness is plotted vs area, the graph follows the equation : log S = log C + Z log A where Z is the slope of the line. Z values are usually in the range of 0.1 to 0.2 but if very large areas like entire continents are analyzed, the slope is much steeper. (0.6-1.2).

Why is it so ?

(Here S = species richness and A= area under consideration)


texts: Estimation of number of species at an earlier time

texts:
The estimated number of species on Earth, as reported in this article is around 8.7 million. I am fascinated by how nature produces such a wide variety of species.

As per my understanding, many species have gone extinct, that is, were not able to adapt to changing conditions on Earth. Perhaps the number of species before few thousands of years were larger than today. Can we estimate the approximate number of species at a given point in the past, using available data?


texts: Are evolutionary algorithms calculated in polynomial time?

texts: How complex are evolutionary algorithms? Also, what is the relationship between variational principles (Lagrangians, minima and maxima,) and evolutionary algorithms? Basically, how hard is it right now to construct an algorithm that reproduces what we see in the evolutionary history of life? Could you, in theory, use variational principles to reduce the complexity of evolutionary algorithms, and gain novel understanding of how evolution works in the process?


texts:
“Before taking lactulose, tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially antacids, antibiotics including neomycin (Mycifradin), and other laxatives.” (Quote from here)

Why do antibiotics have a special importance when taking lactulose?
Why is neomycin (Mycifradin) mentioned separately?


texts: Does the size or mass of a body affect the time it takes for rigor mortis to sets in? For example: compare a 300 pound man to 100 pound girl to 5 pound animal.


texts: Standard notation for crossings (female, male)

texts:
Is there any standard for the notation of a crossing (hybrid) which tells me which part is the mother and which is the father?
Example
StrainA: egg cell
StrainB: sperm cell
Which notation is correct?
StrainA x StrainB or
StrainB x StrainA
or isn't there a rule for this?


texts: Does brain activity generate heat gradients in the brain?

texts:
I'm reading this article on guiding axon growth using temperature gradient, and it mentions that the trajectory of growth of neuron connections can be influenced by temperature gradients as little as 0.1C.

This got me thinking - does thinking generate heat or increases blood flow enough to create heat gradients within the brain? If so, this may explain how the brain rewires itself.


texts:
The Zika virus was already present and known to the world (mostly in Southeast Asia) before the current outbreak.

Why has the virus caused such an extreme outbreak?

Has it mutated from its ancestral form such as that found in Southeast Asia?


texts: What counts as a 'breach of the skin' for infections(like rabies) that spread via wounds?

texts:
I've been looking at several sources on how the virus spreads and they all mention that the skin has to be broken, but does it mean broken to the naked eye?

A minor scratch where the skin appears unbroken and there was no bleeding could still have microscopic breaks of the skin, therefore it seems risky to rely on the naked eye.


texts: After PIP2 has been converted into IP3 and DAG by phospholipase C (PLC), some of the IP3 opens calcium channels in the endoplasmic reticulum and calcium ions can enter the cytoplasm. However, it is unclear to me how this IP3 cascade is terminated. Is IP3 somehow degraded, do high calium concentrations result in closure of the calcium channels or is there some other mechanism?


texts: Why do lions keep young preys and don't kill them right away?

texts: I saw some (actually several) videos on Youtube of young lions and lionesses that after hunting baby preys keep them and even seem to play with them. The lions don't seem to want to hurt them but they don't seem to want to let them go either. Most of the video titles are "lions protecting baby ....", I don't believe that. On the comments people say "the lion is saving it for later". My guess is that the lion wants to give the baby animal for the younger lions. What destiny will the baby prey most probably have?


texts: codon optimization / enzyme active site improvement

texts:
Does one necessarily have to use de novo synthesis of DNA when attempting protein expression improvement by codon optimization? Or are there other ways?

e.g. Say the gene coding for the enzyme needed to synthesize a certain secondary metabolite is known & sequenced already. The standard cloning approach is to extract mRNA from (say) plant tissue, then construct a cDNA library & express it in E Coli using a suitable plasmid.

Now if the neucleotide sequence needs to be modified (to increase expression) does one have to start de novo or is there easier ways that can start from the mRNA / cDNA?

A variant of the same question is when I'd want to modify the gene because a protein docking study shows some ways to modify the active site of the enzyme by changing a residue or two in the amino acid sequence.


texts: Are there any known health benefits / risks from milliampere current (0.1-2 mA) on forehead?

texts:
This is about devices like that sold by foc.us that allows user to apply a small current on a specific part of the forehead.

For the sake of this question I use the foc.us "gamer" model as example. This device has:

a headset with two (moist)electrodes that are positioned on the forehead
a controller unit that is used to apply a (selectable) current between 0.1mA - 2.0mA through the electrodes

[Update:] the electrodes have a surface area of 35mm x 35mm (they are 12mm thick).

According to information received from the company this device is a "micro current signal generator" and can be operated in "tDCS" mode (I am not sure what "tDCS" means). The device has a timer so that it can be set to provide this current between 1 - 40 minutes.

They sell this device with an (explicit or implicit) claim that is helps the wearer improve their ability to focus (on, for example, a game that the wearer is playing).

Are there any known health benefits (such as improved ability to focus) or dangers (damage on the nerve system?) from applying a current on the forehead?


texts: Food allergen-related skin reactions and intestinal inflammation?

texts:
Are there any connections between food allergen-related skin reactions causing intestinal (or more broadly, gastrointestinal) generalized inflammation?

If such a link exists, is it related to any of the inflammatory bowel diseases (Crohn's, colitis, irritable bowel syndrome)?


texts: How does taxonomy work? The case of the Avian Dinosaurs

texts: I recently discovered that the class Aves (or Birds) has been renamed Avian Dinosaurs. My question is when this taxonomic denomination achieved the consensus of the scientific community and through witch process, this change was made.


texts: Is an attraction to studying the philosophy of biology a good reason to pursue grad studies in the field?

texts: I have always leaned more towards questions surrounding psychology, sociology, and philosophy but fate has me graduating with a BSc in Biology this year. Would it be smart to pursue it further more for the aesthetic beauty I find in its ability to shed light on questions beyond itself than for the science purely in itself?


texts: What is the actual mechanism by which ApoA-1 Milano exhibits its phenotype?

texts:
ApoA-1Milano is a variant of the apolipoprotein A-I protein that was discovered by the University of Milan when sequencing the genome of those native to the village Limone sul Garda. The mutation has been shown to dramatically reduce the occurrence of cardiovascular disease for those who carry it. There has been much research invested into developing a means of delivering a synthetic version of this protein to the tissues of people already suffering from cardiovascular disease.
Typically with protein variants as high profile as this one there'd be some consensus or theory as to why the variant performs in the way that it does. For instance, the G171V mutation in the LRP5 gene results in a variant LRP5 protein receptor that reduces the ability of the DKK1 inhibitor to bind to it, resulting in greater LRP5-induced canonical Wnt signaling, which augments load-induced bone formation, which increases bone mass/density.
So a known mutation with a known protein variant as a consequence, the exact structural difference of which is known, and the exact intermolecular consequence of this difference is known, and finally the resulting phenotype is also known.
But in the case of ApoA-1Milano I can't find any literature regarding what the specific intermolecular consequence of this variant is that confers the reduced risk of cardiovascular disease phenotype. Big pharma has gone so far as to inject the variant protein into living human beings since the beneficial nature of it is so definitive but there doesn't seem to be any consensus as to how this variant is beneficial?


texts:
I'm am struggling with genomic DNA extraction from different samples of Pyura chilensis; the DNA is degraded as can be seen on the gel.
We've always used GeneJET Genomic DNA purification Kit (by ThermoFisher), and it works fine for samples from other species; so the kit isn't the problem.
We've always used tissue samples stored in 95% Ethanol (which are washed with water prior to DNA extraction), but the problem persists irrespective of whether the samples are one day old or a few years old.
The storage method seems to work fine for gDNA extraction from other species.
Then, my guess is that the problem is with Pyura itself. So I have to figure out if either the extraction or the storage isn't appropriate for Pyura. I read that Pyura has a lot of copper in it. We planned to use a new buffer for storing it: salt Saturated DMSO, containing EDTA.
I would like to ask if any of you have ever worked with this organism (and if you have, then how did you manage to extract DNA from it). Do you have any suggestions on any DNA purification protocols?

1st lane is the ladder (1kb) and last 3 lanes with long blurred thing instead of bands are my DNA samples.


texts: 3D models of adult male brain in the Blender software? Any open-sourced version for research?

texts: I am trying to find 3D model of brains. I am particularly interested in adult-male -brains in Blender-model. I could find such 3D models of brains for sale here but because I am researching I would like to use some open-sourced candidate so anyone could preview things. So does there exist 3D models of brains in Blender?


texts: Is there any disease in adult human, other-than cancer, which-is resulted from mutation?

texts:
On all environmental articles I read about 3 impacts of mutagens (say Cigarette/ Naphthalene/ EtBr/ Colchicine/ ionizing radiation/ whatever )...

1. direct effect on tissues, other than mutation, such-as burns, choke, cirrhosis of liver, Lesion in lungs etc. (no direct relation with mutation)

2. Mutation affecting development of organs and intelligence, in youngs; and hidden mutation not affecting adults but showing expression (birth-defects) in future progeny.

and

3. Tumor and Cancer.

Now, my question is, if an adult become exposed to some mutagen; the only visible effect of mutation (not about burns etc, talking about genetic-mutation) ... on that affected-individual; whether cancer is the only-possible disease? or it is possible to occur some-other sort of genetic disease  (not about future but only to that particular affected-one)

anything else should happen ... say exact opposite thing... uncontrolled apoptosis that gradually kills whole affected person (for say).

or for say due to a genetic-damage a person became unable to perform cell-division, so no wound healing. If once part of body become cut, and it remain open forever, never seals. (I never heard or read anywhere).

instead of cell-death, they could perform some-other malfunctions, too. Like turning-off certain normal function, say stopped transport of certain molecule, or say stopped a function like color-vision, or start to secrete / accumulate some metabolites same-way as inborn error of metabolism?

But could anything such happen other-than cancer?


texts:
I'm struggling to arrive at the answer to the following question, which appeared on a pre-test of mine and which I am now using to study the material we've learned. According to this helpful video, I am assuming the possibilities for my question are also autosomal recessive, autosomal dominant, x-linked recessive, or x-linked dominant. I tried each approach as Mr. Douch did in the linked video, but I struggled to find a definitive answer. No matter which approach I picked, it seemed plausible that either the boy or the girl could have the trait, but it seems there's no guarantee that both the boy and the girl have to have the trait. During the pretest, I picked the first answer choice, both the boy and the girl, and got the answer correct by mere chance. But to say that the boy and girl are expected to have the trait would imply that there is a great deal of certainty that the trait will be passed on, right?

The pedigree below shows how a physical trait caused by a mitochondrial gene is passed from one generation to the next in a family.

Using this diagram, which children highlighted in yellow would you expect to have this trait?
(A) Both the son and the daughter -- correct, per answer key
(B) Neither the son nor the daughter
(C) The daughter only
(D) The son only

Please let me know what I am doing wrong or if I am not understanding the question wording correctly. Does it have to do with the fact that it's a mitochondrial gene? Thanks.


texts: Why don't intelligent animals like primates use plastic bags?

texts:
I'll be honest here. Although this is a serious question, what made me wonder about it is this comic from Wumo:

This question is not specific to monkeys. It applies to animals that live with or sufficiently close to human dwellings and would be able to observe our habits daily. I'm not referring to training animals.
Even among animals that have an opposable thumb like ours but different HAR regions, the use of tools seems to be too primitive. Chimps have been known to re-use tools and even cumulative cultural evolution is documented. Whales have been hypothesized to have high intelligence (although not necessarily) due to larger brains containing more spindle neurons. But I couldn't find any info on whether whales use tools (Dolphins are said to use sponges though).

On considering if mirror neurons were helping chimps copy each other and use tools, I found that the very existence of mirror neurons in humans is under question.

So if a chimp can use simple tools, what prevents them from looking at us and imitating our use of something as simple as using a plastic bag or a crude tray to carry a bunch of fruits? Is there a gradation of complexity of tool use that various brains can process? A reason that no matter what happens, a chimp would not be able to imitate our use of tools? Could this be compared to how aged people are unable to learn how to use a smartphone or computer no matter how many times it is explained to them (or even how young people fail to understand pointers and recursion)? Perhaps the ability is related to an animal's capability to form new neural connections of a certain type?

Training an animal like Jack the baboon is different from what I'm asking.

Some examples of primates trying to carry many fruits.


texts:
What are these white spots? It's like Braille writing or something.
How is the appearance encoded in the plant? (which I think is a Pine, though I am not sure).


texts: What is the meaning of expansion of T cells?

texts: In immunology, what does it mean by the term 'expansion' of T cells ex-vivo and activate it (generally with reference to cancer immunotherapy)?


texts: Fatty acid oxidation in adrenal medulla?

texts:
Why adrenal medulla can not utilise fatty acids for generation of energy?
What could be the benefit for not having ability to use fatty acids?

Refrence 1

Refrence 2


texts: Why was polyploidy not lethal in certain octodontid rodents?

texts:
As discussed in Why is polyploidy lethal for some organisms while for others is not?, polyploidy is normally lethal in mammals.

However, two species of Octodontidae (South American rodents), are tetraploid due to a recent doubling of all chromosomes:

Tympanoctomys barrerae: 4x = 102
Pipanacoctomys aureus: 4x = 92 (apparently some chromosomes were lost after the polyploidy event)

See the paper discussing T. barrerae, the first of these tetraploid rodents discovered.

According to the Wikipedia article, both are believed descended from the same species, Octomys mimax (or possibly now-extinct close relatives thereof), which has 2x = 2n = 56 chromosomes, half those of T. barrerae.

What was special about Octomys that allows it to survive polyploidy, unlike most mammals?

Interesting:

  The sperm head of Tympanoctomys is is by far the largest naturally occurring in mammals, and its size is causally related to the double genome size it has to accomodate.


texts: Is there any independent non-DNA based information system in the cell

texts:
The information in protein is not neccessarily independent of the genome as the information of amino-acid sequence comes directly from the  genome. The process of post-translational modification may be another candidate but the main players in this process are proteins so its not clear whether this process is totally determined by genome (total DNA-based information) or some portion of it comes from a different source.
Obviously the external world is a source of information but I am interested in internal sources.


texts: User friendly phylogenetic tree editing software

texts:
Background: I have Hackett 2009 (from birdtree.org) phylogenetic tree and I need to reorder it according to Prum 2015. I also work only with some species relevant to my project, not the entire tree.

I currently use Mesquite, and it is absolute purgatory. Doing any reordering in Mesquite takes insane amount of time. I'd also like to add higher taxon information to each species (like order) to help my my orientation in the data.
I understand some of Mesquite's shortcomings might be shortcomings of Nexus format. As I don't need to analyse the data myself, I can work in some better format like PhyloXML as long as it's possible to export back to Nexus format in the end.

Is there any way to do this? Some software with better visual editor (and overall better UX) or other method to do this in effective manner? I find it hard to believe that much bigger data is handled in such clumsy way.


texts:
I have a question regarding the synthesis of glucose from fatty acids. In my book as well as in other posts on stackexchange, it states that fatty acids CANNOT be turned into glucose for the following reason:
Fatty acids are converted into acetyl-CoA, which cannot be reverted into pyruvate because humans do not have the enzyme, but some plants do. Therefore, fatty acids cannot be turned into glucose.
Glycerol however can be converted into glucose by gluconeogenesis.
However, fatty acids can be turned into acetone by ketogenesis and acetones CAN be converted into pyruvate and therefore also into glucose. So doesn't that mean that fatty acids can be turned into glucose?
Fatty acid -> acetyl-CoA -> acetone -> pyruvate -> glucose.
Ketogenesis happens during a carbohydrate deficiency (or diabetes mellitus). The brain is able to use ketones for energy, but preferably uses glucose, so I'd assume some ketones are converted to glucose as well?


texts:
First, my background - I'm a newcomer to biology.

What is a gene circuit, and how might I simulate one in a laboratory? Thank you.


texts: How can I retain cells in suspension for comparative microscopy?

texts:
I am working on a digital holographic microscope. I would like to compare its imaging properties with an actual phase contrast light microscope. My aim is to do this cell by cell, creating a z-stack that shows the same cells in suspension, in a volume with approx. 1-2mm side length. In order to do this, I need to fix each cell firmly in one XYZ position to be able to move them between microscopes.

I am not a trained biologist and I am wondering if there is known procedures/agents to do this. Here's a couple of (non-)requirements I could think of so far:

the cells don't need to live through the process
they should however retain their form for at least couple of minutes (acquisition time)
the agent should be close to translucent and not form bubbles


texts: Why are the human knees and elbows bent in an opposite direction

texts:
I can assume that the hands used to be the same as legs. And they got weaken, and changed direction when human started to walk on two?
Also why do the hand palms facing the body and not facing down like the feet?


texts: Why would glucocorticoids promote glycogenesis and not glycogenolysis?

texts: I read in a textbook that glucocorticoids can stimulate the synthesis of glycogen. I do not understand this at all—shouldn’t glucocorticoids try to increase the blood level of glucose? Why would they be storing glucose as glycogen in the liver and muscles like insulin?


texts: How is the glycemic index computed from a blood sugar curve?

texts:
The definition of the glycemic index is often given as the area under curve (AUC) of their two-hour blood sugar response. However, it's essentially meant to be a measure of whether food causes a fast or slow rise in blood sugar level. Why is the two-hour AUC a good measure of the speed of the rise?
When ingesting the "same" amount of sugar, no matter the form, the AUC should be the same, right? The only explanation I can find is that the two-hour cutoff means some carbohydrates are metabolized beyond that cutoff, so their AUC and hence their GI is lower, is that what's happening?
The reason I'm a bit confused is that all of the images of blood sugar curves illustrating low & high GI seem to show two curves with the same AUC, both going to 0 before the two-hour cutoff.


texts: Does photosynthesis begin instantly when a plant is exposed to light?

texts:
I'm curious to know if the process of photosynthesis has a "ramp-up" time to become useful to a plant, or if it begins instantaneously when the plant is exposed to light after a period of darkness.

For example, if I'm growing a plant indoors using artificial light, does the plant start converting CO2 the very moment I switch on the light, or does it take a certain period of time for the reaction to reach a critical momentum for the plant to be able to produce sugars?

Or, as a thought experiment, if I turned on the light for 10 minutes, would the plant produce roughly the same amount of sugars as if I toggled the light on for 1 minute, then off for 10 minutes, 10 times in a row?


texts: Why is the variance of the Wright-Fisher model not equal p(1-p)/(2N)?

texts:
I was looking at the properties of the Binomial probability distribution and it says that the variance is np(1-p). In population genetics, n = 2N. So I would expect to see that the variance is 2Np(1-p).

But when looking at the Wright-Fisher model, I often see that the variance is $p(1-p)/(2N)$ (see this presentation page 6).

How to derive the variance of the Wright-Fisher model to get this variance from $Prob\{X=i\}=\frac{n!}{i!(n-i)!}p^i(1-p)^{n-i}$?


texts: How is the probability of a sequence occuring with BLAST calculated?

texts: What is the probability that a given nucleotide/amino acid sequence will occur in the whole database program BLAST searches in? How this probability is calculated?


texts: What is the point of a runny nose during a cold?

texts:
What is the biological purpose of having a runny nose during a cold?

Note, this is a different question than "What causes a runny nose" and other similar questions. Those question are about the cause, what starts the nose running. This question is about why? What is the body trying to do by making the nose run.

For example a cough, I'm guessing, is to help remove or loosen gunk in the lungs. Tears seem to have a point of cleaning the eyes. Diarrhea seems to have a point of clearing the bowels. Fevers have a point of killing viruses. Vomiting seems to have a point of getting rid of bad things in the stomach. Sweating seems to have a point of cooling the body down.

During a cold though, while reasons like inflammation etc cause a runny nose, what's the point? Why did we evolve to have runny noses during colds? What's the body trying to achieve by giving us a runny nose, specifically during a cold.


texts:
I found this little bug on my bed and I got curious to know what it was, I did some researches and then I noticed that it is very similar to Zelus Nymph but I can't be sure of it. Can you confirm it?

Here is a processed version of the image:


texts: Gastroenteritis virus causing mutation of the Enterochromaffin cells

texts: I am working on the solution to a worldwide problem: IBS or chronic diarrhea following a viral gastroenteritis infection. I think I have an answer. The only missing piece to the puzzle I found in a research paper discussing the genetic mutation of the Enterochromaffin cells by a gastroenteritis virus. I believe the paper was from Japan.  I had it, but I lost it.  Any help in finding this paper again would be greatly appreciated.


texts:
I understand that a missing part of genetic information is a problem - the cell does not know how to synthesize a specific protein. But why is it a problem when there's one more copy of a chromosome?

Let's say a trisomy of the 21st chromosome occurs, so the person has Down syndrome. What happens on the molecular level that the person develops the way they develop?


texts:
What does take more energy (for a bird): to dive or gliding? My teacher thinks that gliding takes more energy, but I'm not sure about this: when a bird glides, it doesn't do anything (pretty much). But diving is stress, which takes much energy. Or am I wrong?
(edit: I don't mean the "going under the water" diving, but "nose dives")


texts:
Curved Membrane effect: Movements of the  tympanic membrane are more at the periphery than at the centre where malleus is attached which provides some leverage. This is called as curved membrane effect.

I am unable to comprehend how movement is more at periphery than at centre.
Practically movement is more at the centre as can be seen from  this  .gif or from following image:

So, why it is said that movement is more at periphery?


texts: I want to separate 1600 Da peptide on SDS PAGE, on 20% GEL I didn't get any band, How can I separate on PAGE? Can I use 25% SDS PAGE?


texts:
What are the reasons for the oversecretion  of thyroxin in the thyroid glands?
Its name was mentioned in my book but there was no explanation.

What are its symptoms,can it be fatal?


texts: Acid splashing beetle | Germany | Middle Europe

texts:
I found a beetle trapped in the bottom of a staircase. When I tried to put it on a paper, it turned and splashed something like acid in my face. I saw drops on my glasses and it begun to burn on my forhead. It escaped then through the drain grate.

It was about 4 cm long and probably brown (not sure about the colour). All I found were the Brachinus beetles but they seem to be smaller and I heard no explosion.

Does anybody know what kind of beetle this could have been?


texts: DNA genetic testing from dried sweat crystals?

texts: My sons' dad died and I wanted to do any sort of genetic testing possible, as a gift to my sons.  The only item available is dried, crystallized sweat from the bridge of his Oakleys, sadly.  Would there be any significance found in such results?  And, who does this sort of testing?  Thank you.   JK


texts: Is the activity of enzymes in the human body affected by the outer temperature?

texts:
I have to do a research about the enzymes in the human body and the things that affect them. I know that the body temperature affects the activity of enzyemes but I'd like to know if the outer temperature of the air affects them, too?
When the temperature goes to 47°C or more we get tired and exhausted. Is this because the activity of enzymes decrease or is something else?!


texts: How are testosterone levels distributed among men and women?

texts:
Wikipedia tells me that men have 7 to 8 time higher levels of testosterone than women, on average.

Since the hormone is linked with performance in certain athletic events, my hypothesis, which I presented to a disagreeing friend, is that female top athletes in certain fields will have levels above the average male.

I found Why do endocrine profiles in elite athletes differ between sports? (Clinical Diabetes and Endocrinology 2018) which in Figure 10 presented testosterone levels for men and women in a number of olympic athletes:

As you can see in the plot it seems that even in the cohort of olympians there is an overlap, even if small, between men and women. Am I misinterpreting these result? I noticed that the units (nmol/L) are different from those used on Wikipedia (ng/dL), is this somehow important?

So:

Are there information about the distribution of testosterone levels among the general population to help answer the question of the share of women exceeding the average male level?
Am I interpreting the above results correct, are there indeed female olympians with higher testosterone levels than male olympians?

(The mapping between numbers and sport)

  Power Lifting (18 M and 1 W)
  Basketball (27 M and 14 W)
  Football (Soccer; 37 M)
  Swimming (100 M and 91 W)
  Marathon (1 W)
  Canoeing (7 M and 1 W)
  Rowing (36 M and 25 W)
  Cross Country Skiing (8 m and 9 W)
  Alpine Skiing (11 M and 12 W)
  Weight Lifting (10 M and 7 W)
  Judo (26 M)
  Bandy (19 M)
  Ice Hockey (38 M)
  Handball (23 M and 29 W)
  Track and Field (95 M and 49 W)


texts: Dopamine and other neurotransmitter release during music listening

texts: I'm looking for any studies that show a positive curve in respects to music sessions in humans and neurotransmitter release (specifically dopamine, epinephrine, and serotonin.) Any direct links would be great as I attempted googling and cannot find any at all for some reason.


texts: Why do chlorotic leaves have green veins?

texts: If chlorotic leaves are chlorophyll deficient, why should the veins be green? shouldn't all the available chlorophyll be directed to the leaf lamina?


texts: What is Luc Montagnier's research on electromagnetic signals from DNA about?

texts:
After reading a Youtube comment, I started reading on Luc Montagnier's research on electromagnetic signals from DNA. I haven't been able to find a source that would clearly explain what it's about. I would like to know, if possible,

what the claims are exactly;
what experiments were carried out;
whether the results have been replicated independently;
whether the results contradict anything considered firmly established scientific knowledge (it seems Montagnier says they do) and, if so, how;
what the criticism is.

I know it's a lot to ask, but if you could make your answers accessible, it would be great. Please don't refrain from using technical language where it's necessary, but do try to give a general picture for those (including me) who might not understand it.


texts: Is the salt obtained from meat (as the primary diet) nutritionally sufficient?

texts:
This post is derived from that one, where someone says

  if you meant salt as a nutrient such as carbs, protein and all, there is salt in the stuff one eats already.

The background is "Naked and Afraid", a Discovery Channel survival show, where a group of people survive for 21 or 40 days without any cloth or food.

They are not next to a shore. They are in amazon jungle or Solani River Basin in Africa.

The footage shows that the candidates got food by hunting but never got additional salt.

They are hunting in Africa. Don't they need additional salt? Is the amount of salt they got from animals like impala sufficient?