texts: Is it one queen bee per hive or per colony?

texts:
I've come across lots of information on the lifecycle of bees, but I cannot find the answer to my question.

If a beekeeper had, say 6 hives, would there be six queens (one per hive) or one (for the whole colony)? Maybe they would be considered six separate colonies, I'm not sure, but that would be a different question.


texts: Do mutagens ever increase the "rate of evolution"?

texts:
There are a lot of sci-fi plots where mutagens, especially radiation, cause some organism to evolve at an accelerated rate. Obviously evolution does not occur within a single organism and most of the authors behind these works are more concerned with finding a justification for a desired plot rather than adhering to known science. Nonetheless, I'm curious to know if there is any well-known case where such a scenario is true. (To get one obvious reply out of the way, all evolution that we've observed on Earth occurs in the presence of the background radiation experienced on Earth. Also, although mutagens by definition increase the rate of mutation, those mutations can of course be harmful, so the question is whether the effective "rate of evolution" can be increased rather than the rate of mutation.)

Is there any well-known case where introducing mutagens can increase the "rate of evolution" in an experimental evolution study?

By "rate of evolution", I'm informally referring to either the amount of time or the number of generations that pass before some beneficial mutation occurs and is selected for. For example, in the E. Coli strains from Lenski's E. coli evolution experiments, are there any known cases where a mutagen reduces the amount of time or the number of generations required for a non-citrate-metabolizing E. coli strain to acquire the ability to metabolize citrate?


texts: What was the largest flying insectoid pollinator?

texts:
Megachile pluto is a large resin bee whose body length may reach 38 mm and a wingspan of 63.5 mm. But that's nothing compared to the prehistoric and extinct Meganisoptera including the Meganeura, which had 'dragonflies' whose wingspan exceeded 70 centimeters!
There are "recent studies" linking animal gigantism in the Paleolithic to the increased atmospheric oxygen content.
Considering the size of some prehistoric insects I can't help but wonder: how big was the world's biggest insect(oid?) flying pollinator?


texts: I had my students conduct a fermentation experiment manipulating sugar amounts (number of sugar packets in solution) and measuring CO₂ production via capture in a balloon and measuring circumference (very common HS lab experiment). I also had them conduct a trial with two packets of Equal sweetener. To everyone's surprise two packets of the "zero calorie" sweetener produced as much CO₂ as four packets of sugar. Can anyone shed light on why this would have occurred? Equal contains maltodextrin and dextrose in addition to the aspartame. I'm assuming that yeast are able to metabolize one or more of these substances, but I haven't been able to find a more detailed explanation.


texts: How do birds deal with their eyes drying out at high speeds?

texts:
My eyes tear up when cycling at 15 mph, which is nothing compared to bird airspeeds.

Do birds continuously produce lots of tears and blink a lot, or do the eyes self-moisturize from the inside without need of blinking, or are their eye surfaces just dry most of the time and they don't mind?


texts: Help identify this red/black Vietnamese insect

texts: I found this strange insect while on Son Tra, Da Nang in central Vietnam. It was about 4cm long and although it was on the ground, was obviously capable of flying. I've never seen anything like this and would like help identifying it, please. Thanks!


texts: How does SDS-PAGE separate based on mass?

texts:
In SDS-PAGE, electric field and mass-to-charge ratio are approximated to be constant for all proteins. Also, if $F=qE =ma$, then $\frac{m}{q}a=E$.
Thus, all proteins must migrate with a constant acceleration.
So what is the driving force in SDS-PAGE that resolves proteins of different mass? Is it that bigger proteins have a larger size and thus experience larger friction force from the gel sieves? But even if that was true the larger proteins feeling larger resistance forces should be counteracted by their larger migrating force from increased total charge.
Would appreciate if someone could clear up this confusion. Thank you.


texts: Effect of cellular phone towers on human health

texts:
We live in world of mobiles, tablets, PCs and other electronic gadgets. We are continuously exposed to radio frequencies and other cellular frequencies. Generally, all of these waves are very low energy / long wavelength (which makes them non-inonizing). This makes them less probable agents to cause any health problems.

I have been searching for potential effect of cellular phone towers on human health. Towers will emit large number of such waves due to our daily usage of electronic devices. The International Agency for Research on Cancer (IARC) has reported cumulative radiofrequencies are categorized as class 2B (possibly carcinogenic to humans). Does this mean people living near cellular phone towers are more prone to health hazards?

I was searching for scientific reports to support or deny any claim made here. I checked the FDA website for guidelines:

  Under the law, FDA does not review the safety of radiation-emitting consumer products such as cell phones and similar wireless devices before they can be sold, as it does with new drugs or medical devices.... FDA shares regulatory responsibilities for cell phones with the Federal Communications Commission (FCC)

However, the FCC guidelines state:

  The FDA, which has primary jurisdiction for investigating mobile phone safety, has stated that it cannot rule out the possibility of risk

And there are lot of other links to other organizations. I couldn't find any citing of scientific paper. This, again, made me confused as to whether cellular phone towers are safe for people living around them? How does the 'non-thermal' effect of this radiation work? There are few reports (like this and this) which I found but they didn't seem convincing.


texts: What is considered incorrect for a cladogram's time axis?

texts:
I am looking for help (and possibly references) regarding the correct mapping of time in a cladogram. As far as I know, it is considered incorrect to draw a time axis diagonally in a cladogram as shown below:

This setting would lead to conclusions like: Species B and ancestor b lived at the same time, because they would both fall upon the same place on the time axis. But we know this is incorrect. Or is this an acceptable positioning for a time axis?

The image below correctly represents the time axis, if I'm not wrong, using a vertical axis.

This positioning makes it clear that species B and b are not living at the same time. In this case, species B is alive and b is an extinct ancestor.


texts: No. of meiotic divisions to produce specific no. of seeds

texts:
If I want to produce 100 seeds. Then the no. of meiotic divisions is 125 which can be calculated by the formula x + x / 4.

x = no. of seeds produced.

How is this formula derived?


texts: What is difference between High quality and low quality proteins

texts: I have seen in news that some bodybuilder died of taking steroids; when I went through details I learned that  "low quality proteins" contributed to their death. I have studied about linkages in proteins but I don't understand what makes them stronger or weaker. So what is the difference between high quality proteins or low quality proteins? How does low quality protein affect muscular activity or growth?


texts: Are children's ears more vulnerable to loud noise than adults?

texts:
I am interested , what are child's ear development stages?
Do newborns' have already developed (defensed) ear like adults have and there is no much difference with regard being vulnerable toward sudden burst noise, which we (adults) bear easier (i.e. popper burst within 1 meter range)?


texts:
Which part of a female mantises's DNA causes her to be a few times larger than a male mantis?

Do other species have that part of DNA?


texts: Why can we eat salty food, but can't stomach salty water?

texts:
I know that too much sodium is bad for our health. However, it struck me as odd that we like to add salt to pasta sauce or other foods we eat, yet trying to drink salt water can bring on the gag reflex.
Is this because sea water is many times more salty than the salt we would add to our food? Or is there another reason?


texts: What studies are there showing the effectiveness of any substance on canine hypertension?

texts: Searching on http://www.ncbi.nlm.nih.gov I could only find the article titled as "Telmisartan Treatment of Refractory Proteinuria in a Dog".


texts: What is meant by 'topologically continuous' in the context of cell compartmentalisation?

texts:
I am reading the textbook 'Molecular Biology of the Cell', and I am reading the chapter about the compartmentalisation of cells. I have come across the following statement:

The nucleus and the cytosol, which communicate with each other through
nuclear pore complexes and are topologically continuous (although
functionally distinct).

With regards to the above statement, what is meant by 'topologically continuous'? Any insights are appreciated.


texts: Sodium hydroxide grade in library denaturation for NGS

texts: If the NaOH, 1N which I bought does not have the label of molecular biology grade can it be used safely for library denaturation in NGS? Thank you!


texts: Is Zika suspected of causing birth defects only if contracted during pregnancy?

texts:
There seems to be growing evidence that a recently spreading strain of Zika virus is in fact linked to microencephaly and other birth defects in newborns (see here, here, and here for examples).

I understand that this is currently an active area of research and a number of questions remain unanswered. However, even given the current uncertainties, I feel any discussion about when a mother gets infected has been largely ignored by all of the news/media/science outlets I've seen.

My question is: does the virus lead to birth defects only if the mother gets infected during pregnancy, or can a previous (or latent) infection lead to similar birth defects? If the former, does timing of infection during different trimesters matter?


texts: Is there an organism which is "The Opposite of Hydra"?

texts:
My understanding is that if hydra is cut into pieces, each piece can evolve into a new hydra. What I'm looking for is whether there exists an organism with a this property reversed, that is, if two or more such organisms meet, they would form new organism with the same property.

UPDATE: I do not mean the mythical creature, but this one. I should also have stated that I'm (obviously) not a biologist, so my terminology and information about the Hydra genus might be wrong. Despite that, I hope the question is still valid.


texts: Are Zebras white with black stripes, or black with white stripes?

texts: I'm not sure it makes sense, but are zebras black or white below the surface?


texts: Why is the heart not in the middle of the body?

texts:
All mammals that I can think of have a high degree of bilateral symmetry (In fact, almost every animal I can think of is like this).

So why is the human heart not exactly in the middle of the body? An effect of this is that one lung is slightly smaller. Are there any evolutionary theories on why this came to be?


texts: Diastole/systole pressure in transcapillary circulation

texts: The Starling equation factors in hydrostatic pressure and oncotic pressure. Given that the hydrostatic pressure in capillaries is pulsed, alternating between systole and diastole, does reabsorption tend to be favoured in diastole (low hydrostatic pressure, low volume from filtration in systole and therefore high concentration of colloids i.e. high osmotic pressure)?


texts: Frog identification - two different frogs seen in New Zealand

texts:
Me and my friends saw these two frogs in man-made ponds in an area which is undergoing development for residential use. Anyone able to identify these beauties?

Also would be interested as to how these frogs got there, as the pond wouldn't have existed 2-3 years ago and there are none nearby.

Location these were found can be seen in the following link:
https://www.pic2map.com/yibrir.html


texts: What factors cause males to be more common than females in humans, from an evolutionary perspective?

texts:
Fisher's principle states that there should be a 1:1 ratio between males and females born on average for a population.  However, if you look at birth statistics your find that boys are slightly more likely to be born then girls.   This article talks a little about how it happens

If it was truly advantageous for an even sex ratio to exist at birth I imagine we would have evolved to make that happen, by slightly favoring more female sperm or by having the processes that decides which embryos to spontaneously abort be stricter for males embryos then females.  For that matter since it's more important for males to be exceptionally healthy then it is for females, since males have to compete for a mate while females don't, you would think more strict filtering for 'bad' embryos in the case of males then females would make sense anyways.

Thus I'm inclined to think that the increased number of males to females is not random evolutionary fluke, but adaptive.  I'm wondering what would cause there to be a benefit for males to be slightly more common then females.

I know males are more likely to die in childhood, due to risk taking activities to impress the females, so could it be that the increase in males is due to the expectation that more males will die before reaching sexual maturity?  I'm not certain I buy this logic, it doesn't seem you should favor a sex any more because it's likely to take higher risks.

I know that strong/healthy mates would prefer males and weak ones prefer females, since strong males would out compete weak males for mates it's good to have strong males that can achieve multiple mates and weak females since their guaranteed to have at least one mate.  Is it possible that our increased nutrition and health of recent generations simply results in more males because our bodies judge each of us as 'healthy' compared to the standard that existed for 99% of our evolution, ie, evolution hasn't caught up with technology when judging health to decide which sex to favor?

Is there some more obvious explanation for why favoring males slightly would be adaptive in humans?

Edit: I want to stress again, I'm not asking how the bias happens.  The article I linked clearly explains what causes males to occur more in terms of pregnancy.  I'm asking why the bias happens.  This could be evolved away in the past if it was disadvantageous,  Whatever mechanisms cause there to be a bias this bias is presumably adaptive for it not to be evolved away.  Both the possible duplicate and the current answer only address what causes the bias to happen today, not why it would be evolutionarily adaptive to have.


texts: Do jellyfish have extra energy reserves for emergencies (a "fight or flight" response)?

texts:
My friend is writing a story about jellyfish, and we couldn't find out if jellyfish have the equivalent of a "fight or flight response" or an adrenaline rush. In other words, do they have reserves of energy which lets them do things they wouldn't normally be able to (such as surpass harder obstacles, or move faster even when exhausted) which only get released during emergencies?
I know that jellyfish have a distributed nervous system and no brain, but searching the web for "adrenaline rush" and "fight or flight response" only returned results about how adrenaline/epinephrene is a cure for jellyfish stings rather than speaking about equivalent phenomena for jellyfish themselves.

Side note: This comprehensive article in Current Biology mentions something called "escape swimming":

One of the most extensive studies of the neuronal mechanisms of jellyfish behavior has been done on the control of swimming in the hydromedusa Aglantha digitale. Atypically for hydromedusae, Aglantha has two different swimming modes: slow swimming and escape swimming. Slow swimming is their normal mode, and is mediated by relatively regular and weak propulsion of the bell governed by pacemaker neurons in the nerve rings. Escape swimming produces a much stronger contraction of the bell, and is triggered when one of the giant neurons in the nerve rings (ring giant) is excited by mechanical stimulation of the tentacles

This is more related to neuronal impulses than energy reserves, but perhaps escape swimming bears some relation to energy reserves as well (if that's something that exists for jellyfish)?


texts: how food moves in horizontal coils of small intestines

texts:
This is a very very basic question, and I am looking at it more from point of view of physics. The small intestine is a highly coiled structure, which means it has horizontal coils as well. I can understand the vertical downward movement of food (when the person is in standing position) due to gravity, but how come the food can move in horizontal direction?

Any insights will be highly appreciated.

Thanks


texts: What problem does the Dobzhansky-Muller Model resolve?

texts:
This page describes the Dobzhansky-Muller model and I can follow the illustration of the split leading to incompatible hybrids.

But at the start of the page the author states "[Dobzhansky and Muller] both realized that hybrid inviability or sterility was unlikely to arise from a single change at one locus." I don't really understand the explanation that follows i.e. what exactly is the issue with having a single change at one locus?

I wonder if someone here could explain the issue more clearly.


texts: Classification and differences between homologous, homoplastic, analogous, derived and ancestral traits?

texts:
My question is contextualised for basic phylogeny knowledge. Here is my understanding: similar or identical traits between any two species, at the basic level, can be either homologous, meaning the trait is developed from a common ancestor, or homoplastic, meaning that the trait was independently developed.

Homologous traits can be either ancestral or derived, and derived traits are a subset of ancestral traits as derived traits need to be from the most recent common ancestor.

Homoplastic traits can be analogous, meaning they developed independently without any common ancestor or commmon initial trait, or can be traits that arose due to convergence, where species with the same (distance/close) ancestor independently developed the traits.

Please evaluate whether my understanding is correct.


texts:
In an article (Guerrero and Tye, 2009) it talks about endochorous dispersers.

Guerrero, A. M., and A. Tye. 2009. Darwin's Finches as Seed Predators and Dispersers. The Wilson Journal of Ornithology 121:752–764.

  The highest proportions of feces containing viable seeds were of Small
  Ground Finch (G. fuliginosa) and the ‘‘insectivorous’’ species
  Woodpecker Finch (Camarhynchus pallidus) and Warbler Finch (Certhidea
  olivacea). These two may be more important endochorous dispersers than
  other species that eat more fruit but are better seed predators.
  Intact seeds were found in 23% of fecal samples; 50% of the samples
  with intact seeds had viable seeds.

I've looked on google and found nothing...

Do you know what that means?

It seems it relates to mast-fruiting plant species.


texts: Is telomere shortening consistant over consecutive cell divisions from zygote to a differentiated cell?

texts:
Considering the complexity of embryogenesis, a temporal referance would be helpful to coordinate the developmental sequences during embryogenesis and fetal development which is to be completed within the gestation period. Can telomere shortening if consistant be used as a reference by every cell to do what it is destined to do at particular time frame? This is without considering the influence of telomerase etc.

This is also without prejudice to the role of DNA directed molecular signalling.

To repeat the question is telomere shortening consistant over consecutive cell divisions from zygote to a differentiated cell? If so can it function as temporal control of embryogenesis?


texts: A plant in my aquarium seems to be growing small plants under its leaves, what's going on?

texts:
In my aquarium I have this plant. I think it's a kind of swordplant. I've loosely attached it to a large piece of driftwood in the hope that it will grow itself on there, I saw that they had done the same in the petstore.

Now recently other plants have started to grow from under its leaves. I've tried to take a picture of it, these are the biggest ones but there are smaller ones on other leaves:

The plant seems to be doing pretty well, I added some iron and fertiliser to the water. The aquarium is positioned so that it catches a bit of direct sunlight late in the day and tons of indirect sunlight almost all day. It also houses shrimps and two apple snails.

My question: What are these small leaves? Is the plant procreating or does are these some kind of parasitical plants of another species?


texts: How does the immune system distinguish own and foreign antibodies?

texts:
Therapeutic antibodies, for example Rituximab which recognises CD20 on B lymphoma cells, can cause adverse effects (e.g. http://www.ncbi.nlm.nih.gov/pubmed/19399690)

One reason behind these adverse effects could of course be an over-response of immune cells stimulated by the Fc region of antibodies attached to lymphona cells.

However, it could also be thinkable that the immune system launches a response against the antibody itself, recognising it as foreign. Does this occur? If so, what part of the injected antibody acts as the epitope recognised by immune cells as foreign?


texts: Can bacteria be reservoirs for animal viruses?

texts:
When people talk about reservoirs, they usually talk about bats, dogs, deer, etc. All animals. But can bacteria be reservoirs for animal viruses? Any examples?

I know that bacterial viruses can at least infect bacteria (bacteriophage). But can animal viruses also hide in bacteria for extended periods and come out at "will" by commandeering bacterial machinery?

I know that bacteria have different polymerases and ribosomes than animals, but is this at least a theoretical possibility?


texts: How would a plant sprout and grow in a zero gravity environment?

texts: Have any experiments been carried out involving sprouting and growing plants in a zero gravity environment? If so, what was the outcome? How did the plants sprout out of the soil without gravity? Did they grow outward or toward light sources?


texts: When to decide that two similar sequences are different genes or not?

texts:
Working on RNA-Seq data directed me to ask this question. In RNA-Seq jobs, after de novo assembly we have lots of transcripts with different rates of similarity (0 to almost 100 percent) that we sometimes don't know their loci.

So regardless of locus, on what reasons we differentiate two or more sequences?

How can we differentiate alleles of a gene from paralogous genes?

I hope my question is clear enough.


texts: Why are animal mitochondrial genomes so conserved and small in comparison to those of plants?

texts:
Background

Levings and Brown (1989):

  Higher plant mitochondrial genomes are much larger and
  more complex than those of other organisms. They vary
  in size from about 200 kb in Brassica species to 2500 kb
  in watermelon, which is substantially larger and more variable
  than mammalian (15-18 kb) or fungal (18-78 kb) mitochondrial
  (mt) DNAs

Boore (1999):

  Animal mitochondrial DNA is a small, extrachromosomal genome, typically ∼16 kb in size. With few exceptions, all animal mitochondrial genomes contain the same 37 genes: two for rRNAs, 13 for proteins and 22 for tRNAs.

Question

Why are animal mitochondrial genomes so conserved and so small in comparison to those of plants?


texts: What determines whether a substance can diffuse across the blood-brain-barrier?

texts: What determines whether a chemical substance is able to cross the blood-brain-barrier via passive, transmembrane diffusion?  What structurally differentiates these chemicals?


texts:
I have been learning about recombination frequencies, but an still getting a bit confused despite having gone over many of the links in Google regarding them. I was wondering if someone could verify whether the following is correct.

To calculate recombiation frequencies and thus create a genetic map from this, you have to have true breeding parents for two or more different genes.
You have to cross these parents, so that you have an F1 generation consisting only of heterozygotes
You then have to backcross the F1 individuals with either of the parents. If these genes are all located on different chromosomes you will just get independent chromosome segregation and therefore a 50/50 chance of each allele occuring with the other one in the progeny. Whereas if they occur on the same chromosome, then in the F1 heterozygotes the alleles from each parent will only segregate differently into the gametes if recombination occurs.
To calculate the recombination frequencies we therefore take the number of offspring for which the combination of these two alleles is different from that observed in the parents- we call these the recombinants.

Is this correct?


texts: Number of reading frames in nucleotide sequence

texts:
In class of molecular biology was posed this question:

"How many reading frames start in sequence of nucleotides 5' ... ATATGAATGATGACAT... 3' ?"


texts: Adult Bugs in Low Humidity House Heated With Wood?

texts:
I have a home heated with wood. The humidity is currently around 30% but I'm guessing these bugs have reproduced when the humidity was higher. They really have a hard time when I see them in the basement.

I do have some wood that was a little punky. They seem to come out as soon as I start a fire in the stove, probably due to the heat?

Approx 3cm long

Located in the eastern townships of Quebec, Canada. Any suggestion on what this is and how to treat them?


texts: What are the relative roles of coding DNA versus regulatory DNA thought to be in evolution?

texts:
Intuitively, once you have the idea that some DNA is responsible for turning on and off the DNA that codes for proteins, it's possible to imagine that the regulatory DNA is actually the most important part. In the ingredients list of a recipe, you might think the coding DNA gives you the list of ingredients, but the regulatory DNA gives you the amounts of each one, plus the order in which you add them to the bowl. If that's true, then different variants of regulatory DNA should be selected for and against, and evolutionary molecular biologists ought to be tracking those variants like they track alleles of genes. But evolution always is discussed as if it's just about different gene frequencies.
Is "regulatory evolution" a thing? If so, is there an understanding of how big a thing it is? Or, if not, why not?


texts: How do transitional forms survive without the full adaptation?

texts:
This may be an odd question, but this is one thing I've always wondered. How does a dragonfly ancestor with early structures that will one day become wings gain any benefit from these useless limbs that don't work?

It seems in an intermediary context like this, that the adaptation would almost fall under a category more along the lines of something vestigial--something defunct.

I understand the creature adapts with no understanding or control of the process, and it takes extremely long periods of time to see any significant changes from one anatomy to another, but it would seem that statistically that would work against the animal, not for it. It's not like the dragonfly goes from the land and water to having fancy new fully operational wings.

The longer a species is stuck with an unhelpful adaptation, the longer they would be exposed and at a disadvantage. There is one way in which I could see this happening, and that is a prolonged series of random mutation in favor a winged route for the insect with no real input from their environment.

We all know that mutation and variation drift (all of which are relatively random) are part of the evolutionary process, but it is often described in more concrete terms, and the creatures in between an ancestor and a descendant have been discovered and described, but often not very well to the public.

The mutant albino bear ancestor being better suited for arctic stealth and eventually becoming the polar bear and diverging from the brown bear is an example given in the new Cosmos that actually could happen overnight. The bear is born with the full adaptation.

Even if the bear weren't instantly white, fur slowly becoming lighter leading to better hiding capability, or having a thicker coat to help it keep warm makes more sense than the precursor to an entire limb like wings or a tail though.

I suppose that it's possible to say the that random mutation is the primary method of evolution, and the apparent improbability of plants and animals surviving with incomplete, underdeveloped adaptations can be answered by realizing that the plants and animals alive today are the cousins of countless species that actually weren't helped by the wings, and some of that is random too.

And with that in mind, it's slightly more obvious, but I'm wondering if there's more to it or something I'm overlooking.

I've struggled to find any discussion about this topic in the literature, which I may have simply missed because it often goes over my head. I'm hoping my conclusion is helpful.


texts: Are 2A cleavage sites functional in bacteria?

texts:
In mammalian cell lines, 2A self-cleaving peptides are frequently used to for expression of multiple genes from a single transcript. They've got some issues, e.g., leaving some proteins as fusions, but so do all of the other options, so 2As are a pretty good choice for many situations.
I have found 2As being used in many other organisms as well, including yeast and plants, but they seem to generally not be used for bacteria.  I've found a couple of articles (e.g. [1], [2]) that do claim to have successfully used 2A sequences in bacteria. If this actually worked well, however, I would expect to see it much more widely used.
Are 2A sites in fact functional in bacteria and, if so, are there any issues that inhibit their use there?


texts: Why don't antiseptic agents kill 100% germs?

texts:
I've seen innumerable antiseptic, mouthwash, handwash advertisements that claim to be able to eliminate as much as 99.9% of all germs over a surface...but why not the remaining 0.1% (i.e- why can't they eliminate all germs)?

Clarifications:

What they mean by "germs":

Being a student of Biology, I can tell that the term "germs" is crudely defined. I would prefer to use "pathogens" (less ambiguous), and I suppose the guys that market these products have (roughly) the same idea in mind. Pathogens normally include bacteria (monerans), protozoans, fungi and viruses... so I guess these are the "germs" they're talking about.

What I'm looking for in an answer:

Why is it that these (commercial) products can't eliminate 100% of all pathogens? Is this due to the inability of antiseptics to act on a particular (class of) organisms? If so, what's the problem there? Or is it because, the guys who market stuff like this assume an arbitrary amount (0.1%) of the pathogens present on a surface (say, the human hand) is located in microscopic niches that are inaccessible to the antiseptic solution? (If it isn't possible to provide a blanket statement in this regard, use of Listerine as an example will suffice)

In other words:

Is an antiseptic's inability to eliminate 100% of all germs due to its "chemistry", or is it due to physical factors?

Also,

Do antiseptics/mouthwashes/handwashes even kill 99.9% of all germs in the first place? Or is it (as I strongly suspect) an example of marketing fraud?


texts: I am looking for some help identifying this bug. I am in southern New Mexico, US. There are a handful of these on the inside and outside of all the window panes on one side of my house. They are about 3mm long. They appear this time of year (late April/early May), stay on the windows for a a week or so and then disappear.  Hard to get a clear picture as they are so small. Any assistance would be greatly appreciated. Thank you!


texts:
I have a ponytail tree plant. The new growth look anemic, pale and thin. And several leave have browned from the midway to the ends of the leaves. The stem is woody and firm. Though it is in a solid pot, the soil tests dry, and there seems to be reasonable space for root growth. I have just moved it so it can get eastern morning sun for several hours. I have tested the pH of the soil and it tested to be a pH of 4.0. Can someone help me diagnose and treat my plant.

Thank you.


texts: Why are sutural bones more common in lambdoid suture?

texts:
Why are sutural bones (Wormian bones) are more commonly present at lambdoid suture? Is the tortuous nature of lambdoid suture a reason for that?

Evidences for my claim:

  They(sutural bones) occur most frequently in the course of the lambdoid suture, which is more tortuous than other sutures. They are also occasionally seen within the sagittal and coronal sutures. (1)

  They are commonly found in the lambdoid suture and fontanelles but are occasionally seen in other sutures especially the coronal, squamosal, and sagittal sutures. We examined 25 dried human skulls with the aim to find out the occurrence and variations of Wormian bones, and surprisingly we found Wormian bones in the coronal, squamosal, and sagittal sutures in 6 skulls. These are uncommon sites of occurrence of sutural bones as reported in the literature. These findings prompted us to report these cases as their presence can lead to confusion in diagnosis in cases of skull fractures.(2)

Sources:

1- https://en.wikipedia.org/wiki/Wormian_bones

2- https://www.ncbi.nlm.nih.gov/pubmed/22117248


texts: Why human body cannot defend against HIV?

texts: Some says that HIV destroy IRF3, and some says HIV overruns T-cells.


texts: Examining antibody - target interactions in PyMOL

texts:
I'm a student currently looking at antibody responses against a viral target protein of interest.

I have my own, annotated PyMOL session of my protein and I also have .pdbs of crystallised antibody structures that bind to this protein and rougly know whereabouts it binds. I would like to know if it is possible to combine these two structures into a single session to observe or at least overlay the two structures together. Many thanks!


texts:
In regards to a published paper of a spider about to make a meal out of a parasitic wasp (http://www.tandfonline.com/doi/abs/10.1080/08912963.2011.640399#.U1kSV14gVBU), it reminded me of a issue I've often contemplating for some time:

Isn't tree resin very slow moving, for instance maple sap has an extremely high viscosity and therefore how does the resin engulf both an arthropod, such as a spider, quick enough for it to not move away from the slowly moving amber?


texts: Tonight I have found this new friend flyng inside my home. First time ever I sea something like this here in the north East of Italy


texts: What is this plant with pink flowers and maple tree shaped leaves?

texts:
This plant goes in my front yard in morning sun in the interior of British Columbia.

It has green leaves initially and then they curl brown and turn yellow. It gets water weekly but not lots. Is it okay to divide this plant to thin it out?


texts: Is the immune system suppressed during sleep?

texts: Of course we have heard that during stress our immune system is suppressed. This leads me to wonder, does the immune system get suppressed when we are sleeping and why? During both these conditions the body might need to save energy for other biochemical processes, so I wouldn't be surprised that the immune system is suppressed while a person is asleep.


texts: What are the effect of radioactivity on grey wolves in Chernobyl?

texts:
I am doing some research about the effects that radioactivity has and is having on grey wolves in Chernobyl and more particularly on their genetics, but maybe also looking at the populations in the area as a whole.
I was wondering if anyone has any knowledge or resources they could share. It would be great!


texts: Below which temperature human muscles don't work?

texts:
When one exposes theirs body parts to cold environment (especially foot and hands), they may be numb, with temporarily blocked both muscles.

What is typical body temperature below which human muscles don't work properly?

Moreover, what is the mechanism behind it?

EDIT:

Interested in case when muscles almost cease to work (e.g one is not able to grasp a cup), not just in small perturbations to strength.


texts: What factors may lead to a difference in whole-cell potency compared to cell-free potency?

texts:
For studies of protein-ligand binding, the reported whole-cell potency may be higher or lower compared to measured cell-free potencies.

For decreased potency, this may represent an increase in non-specific binding of the ligand. Are there other factors that may contribute?

On increased potency, I've noticed this applied to the BACE1 protein in which the IC50 may go on the micromolar scale in a cell-free assay to nanomolar scale in a whole-cell assay. This seems counterintuitive to me. Are there possible reasons for this trend?


texts: What is the minimum number of clades necessary to partition Vertebrates while maintaining the classical groups of Birds, Mammals, and Amphibians?

texts:
At school I was taught the Linnaean view of vertebrate life - that vertebrate animals consisted of 5 distinct groups: mammals, birds, reptiles, amphibians, fish.

I learned later however that this was phylogenetically inaccurate, with birds being 'closer related' to crocodiles than other reptiles are, for example.

As such I am curious - since the idea of these groupings is so strong in popular conceptions of animals:

What is the minimum number of clades we would need in order to partition 'Vertebrates', maintaining 'Mammals', 'Amphibians', and 'Birds' as clades?


texts: What does the presence of 6 molecules of water in this equation indicates to?

texts:
so I was studying biology today and I went over this weird question that says:

The presence of 6 molecules of water in this equation:
C6 H12 O6 + 6O2 --> 6CO2 + 6H20, Indicates that the:
a) Complete Glycolysis of a glucose molecule (Obviously not correct)
b) Occurrence of Krebs cycle Twice
c) Complete occurrence of oxidative phosphorylation process
d) Storage of energy in NADH and FADH2 molecules

Alright so this is the oxidation of one mole of glucose equation (Without the ATPs) but till now I don't exactly know the correct answer for this question, but to not create any confusion this question is related to the Aerobic respiration (Glycolysis, Krebs Cycle and Electron transport chain).

Here's how I approached this question:

(a) is obviously not correct because the products of glycloysis are 2 pyruvate molecules and 2 ATP molecules so I checked off this choice.

(b) However seems correct because the products of 2 Krebs cycle is 4 CO2 and there is already 2CO2 when the pyruvate acid formed the 2 acetyl CoA molecules so in total that's 6CO2, but still what about the 6 Water molecules?

(c) is a very debating choice because when there is a "Complete occurrence of oxidative phosphorylation process" so that means 2 Krebs cycles had already occurred and formed the 6CO2, and during the oxidative phosphorylation process Water molecules are formed. and ATPs too? I don't exactly know about the ATPs, but aren't they supposed to be in the equation's products in order for this choice to be correct?

(d) This choice indicates to Krebs cycle but the water molecules only are formed during oxidative phosphorylation only.

So basically all the choices seems very debating and confusing and if I were to choose then I'll go with (C) because it's the only choice that makes sense for the water molecules (and the question asks for water), but I want someone to please answer this question with a brief explanation to why he chose this answer,

Thanks :)


texts: How do lipid-soluble substances diffuse through the cell membrane?

texts: It’s said that water-soluble substances can diffuse through cell membrane with less ease than lipid-soluble substances because the former encounters impedance in the hydrophobic region of the phospholipid bilayer. However, does the same logic not apply for hydrophobic substances, in that they cannot traverse the hydrophilic outer/inner surfaces of the plasma membrane? How would they be able to enter or leave the cell with greater ease?


texts: background extraction in microscope analysis

texts: I have taken microscope pictures for proteins in HeLa cells, in order to quantify the intensity (immunofluorescence). The proteins are both at the nuclear envelope, and in order to quantify the intensity I draw a line that goes across the whole cell,through the nucleus, and measure the intensity on that line (ImageJ). Which value should I use as background?


texts: can you tell someone's age from a DNA sample?

texts: So as I understand it telomeres shorten as you age. Working under that assumption..  let's say you were investigating a crime and there was some DNA evidence that had been left behind. Could you determine the age of the DNA owner by looking at the telomere length?


texts: What is the Definition of Homologous Chromosomes? length, gene position are the same or similar?

texts:
what is the Definition of Homologous Chromosomes?

this post says

  Homologous chromosomes are chromosome pairs (one from each parent)
  that are similar in length, gene position, and centromere
  location.

and then

  The position of the genes on each homologous chromosome is the same.

are length, gene position of a pair of chromosomes the same or similar?

if exactly the same (I guess not), job well done.

if just similar, What is the Definition of similar? 99% same?

in the case of a pair of human Chromosome 1, what is the exact number of base pairs that are the same?


texts: Why will world population keep growing if all women have only 2.1 children

texts: Why is it that, even if we were going to immediately agree that every women will not have more than 2.1 children on average, the world population would continue to grow for another 60 years? I've learned that a TFR of 2.1 means the population is at 0 growth rate. I guessed the answer was the population-lag effect, but since we are assuming that ALL women immediately have only 2.1 children on average, wouldn't there be a 0 population growth immediately and not after 60 years? Thanks in advance!


texts: What is the H+ gradient in mitochondria?

texts:
I would like to understand what the term H+ Gradient means. I googled this question and found terms such as chemiosmosis and ion gradient being tossed around. I am very new to biology and I do not know any advanced terms or anything of the like. What I do understand is that the mitochondria produces ATP and has something called a proton pump.

Thank you in advance.


texts: Is the human collarbone supposed to break?

texts:
I've read it in a book and have heard people mention it, but I can't find any documentation about it. But the point being made is this:

  The human collarbone acts as a shock absorber for impact on the shoulder or stretched arm. If too much force is put on the shoulder (EG: during a fall), the collarbone is designed to break to prevent injury to the neck and/or head.

Is this actually true and if so, can anybody point me to some documentation about it?


texts: How much difference in genome is enough to prevent interbreeding?

texts:
I am not a biologist. I am a software developer interested in genetic algorithms therefore i am probably talking to biologists who also have a knowledge of genetic algorithms. I need to "breed" different solutions to a problem while allowing the number of genes in my solution to vary because i don't know in advance how many genes i need. This is why i need to be able to cross solutions with N genes with solutions with M genes and this is a serious problem. If N and M are very different the problem would be even more serious. I want to know what happens in the biological world. I am trying to understand how much difference in genome is "enough" to prevent interbreeding between different organisms. Would it be possible to say that if less than (approximately) X% of the genes of two organisms are different then they can probably mate and have offspring?
Thank you

Wentu


texts: What are these plants, which resemble short pink sunflowers, in this photograph from Kerguelen island?


texts: Why are there exactly 207 morpho-electrical types of neurons?

texts:
I'm taking an introductory neuroscience course online, and it mentions that of the 55 morphological types and the 11 electrical types, there are 207 morpho-electrical types.  How does this work?  55 times 11 is 605, so it's not a simple mapping of 1 to 1. 207 isn't a factor of and doesn't share any proper divisors with 605, but it's roughly 1/3 (but not exactly). I don't see how a third makes sense though.

What causes exactly 207 morpho-electrical types?

Feel free to let me know if I should move this to Health or Psychology.SE, I'm not quite sure where to post this.


texts: Can a color-deficient person be made to visualize the missing colors?

texts:
Hope this is within the scope of this site.

Color-deficient persons lack the cells in their retina needed for differentiating some (or all) colors.

However, the part of the brain that actually processes images is not deficient.

Is it possible to somehow make a color-deficient person "see" the missing colors by directly activating that part of the brain responsible for processing colors?


texts: How much variation in the human genome for humans

texts: We are currently learning about the Human Genome Project in high school biology. Wouldn't the human genome that was mapped be different from, say, mine if it was mapped? How much variation is there between individual humans in our genetic sequencing? I'm assuming there is not that much difference since multiple volunteers were used in the project. I did see another question that talked about mutation rate, so I'm not sure if that's the same thing.


texts: How to dialyze large amounts of precipitated enzyme solution (ammonium sulfate)?

texts:
I am no biochemist, but I want to purify some liters of solution through dialysis. What I know are those dialysis tubes in glas vessels on stir plates for labs. But how is this done in industry for bigger quantities in an affordable way?
Background: The solution contains a precipitated enzyme (183 kDa) with ammonium sulfate (132 Da). I want to take away the ammonium sulfate to get back the active state of the enzyme.


texts:
I performed real-time PCR and I was looking for expression fold changes for 2 genes and I had two sample pools, one treated and the other not treated (for each gene). The problem is that my housekeeping gene (UBQ 30) got a fold change on the treatment. Therefore, what is the correct interpretation and data treatment?

I mean, is it correct to use each control and treatment I got for UBQ CT values to normalize the other two genes corresponding CT, as housekeeping genes are "by definition" expected not to change? (and that is why indeed they are used to normalize)

or should I rather make a mean of my whole UBQ CT-s and normalize all other genes CT values with that mean?


texts: If I put a piece of wood in a humid environment (basically humid air), it will start to rot. Does the humidity influence the rotting speed, and if so, what is the relation between the rotting speed and humidity?


texts: Can severe vasoconstriction increase systolic blood pressure?

texts: I know that, vasoconstriction results in increased total peripheral resistance which is responsible for the rise in diastolic blood pressure. Also, cardiac output is responsible for the systolic blood pressure. But there are conditions, as in administering nor adrenaline, where there is severe vasoconstriction and a fall in cardiac output but a rise in both systolic and diastolic blood pressure. In this case, I understand that the rise in diastolic blood pressure is due to vasoconstriction produced by nor adrenaline. I am not able to account for   the rise in systolic blood pressure in the setting of falling cardiac output. Can severe vasoconstriction also influence the systolic blood pressure?


texts: Is scalable growth the main reason why Darwinian systems select Fibonacci sequences?

texts:
The other day I was thinking about evolution of multi-cellular organisms, and why from the earliest onset of the development of communal cellular structure building, life may have selected a simplest possible strategy for building scale-able structures.

We humans employ relatively complex mathematics and measuring tapes to engineer structures, and we build them to full size, or modular so they assemble. We like proportionality, and there are strength and weight considerations associated with it, but we are not entirely ruled by these considerations. But it maybe that life is far more dependent on proportionality considerations. Life grows sequentially from a single cell, and each cell possesses both the building machinery, and what must be a relatively simple genetic program to govern growth. Because the generic programming operates on the basis of individual cells, there is conceivably a limit to the complexity of program you can expect life to be employing. And even if genetic coding is capable of tremendous complexity, life’s still going to select the simplest most effective approach. So how does lifes growth system achieve such consistently proportional results?

The answer may reveal itself, when you try to conceive of a building method that achieves the same outcome life does. That is to say, building a small scale structure, that will later scale up to full size through a growth cycle, and maintain a proportionality. If for example you build a small scale brick building, whereby the bricks can replicate and divide like living cells. Then so long as each brick does so at an overall synchronous rate, starts with select proportions and follows a very simple program governing growth that abides a proportionality which stays constant at all scales. Like the Fibonacci series rectangle does. Then the building can be scaled up through a smooth growth cycle while remaining structurally proportional. What you start with will determine your end result. And most importantly, having used a minimalistic coding system.

So what’s interesting, is that this is potentially a sound reasoning for why Fibonacci series emerges from such a fundamental level within Darwinian life. Life in the oceans subsisted as single celled organisms, but as soon as it started experimenting with multi-cellular structures, it needed to solve these issues of scale-able growth.

If this is correct, then it opens a fascinating window on a process of early life. Who knows what types of biological evolutionary insights might be derived from it.

Does this scenario sound plausible to more people than just me?


texts: Is the sense for salt depending on the electrolyte level in our body?

texts:
I often noticed, after (heavy) physical activity like cycling, running, swimming or working an isotonic drink (to recover the electrolyte level) tastes less "salty" compared to when drinking it before the activity.

Is this possible or am I just hallucinating?

The object of this (if it's real) could be:

to save us of taking too much salt
to reduce the reluctance against salt if our body is undersupplied (with sodium ions)

My guess is, that the electrolyte or particularly the sodium (chloride) level in our body influences the cells/nerves that sense the taste for salt on our tongue.

Wikipedia says this:

  Salts, sweet, sour and umami tastes causes depolarization of the taste cells, although different mechanisms are applied.

So, I imagine it like this:

If there is enough salt in our body, the cells are saturated with e.g. sodium ions (higher polarization since there are more ions)
NaCl and other salts (probably KCl too) will then dissociate into Na+ and Cl- (etc.)
The Cl- will then attract more Na+ from the cells causing deplolarization
Our brain converts these signals into the proper perception

But maybe I'm just hallucinating... :)


texts: Online repositories of scanning electron microscope photographs?

texts: I have looked at every single Wikimedia commons photo in the category 'scanning electron microscope'. Unfortunately, I could not find any other repositories of such photos, but I would readily look at every single photograph there as well. It strikes me that such repositories are also bound to be useful to biologists and biology students. A simple Google search did not yield much. Can anyone help out?


texts: Book request: systematics and evolution of vertebrates

texts:
Would you recommend any good vertebrate systematics & evolution book?

The main goal is to teach a Master's level class - mostly focused on amphibia, reptiles and fish.


texts: Are there evolutionary advantages for the bee sting to kill the bee?

texts: The question title says it all: are there advantages for the sting of a bee to kill the bee? It seems to me getting rid of this would have only advantages, and might've been selected for if a mutation like that occurred.


texts: Was iron important for the first life on Earth?

texts:
Some ions or compounds are thought not to have become involved or important in the metabolism of living organisms until some time after certain mutations took place. For instance, early life is thought to selectively allow calcium ions through its membrane, but eventually also evolved the ability to selectively allow sodium ions, specifically through a mutation that lead to a change in the composition of a channel protein from glutamine to lysine.

Currently, iron is involved in oxidations involving molecular oxygen, such as in cytochromes and clearly holds a key role in modern life, despite that free iron or even ferric compounds are rarely accessible. From my understanding, iron most likely became incorporated into the metabolism of microbes after during/after aerobic organisms had developed, but this does not rule out the possibility that iron was involved earlier on. So, I am wondering if iron was involved in early life, and details on how would be appreciated.


texts: The relation of a schizophrenia drug side effect and caffeine intake

texts: I am listening to the book Surviving Schizophrenia and in the book, it is mentioned that drugs like Clozapine increases in blood level if the patient takes Caffeine, and can have side effects due to elevated levels. In case the patient takes Caffeine, can't just less amount of Clozapine work since it'll be significant enough to help the patient and cause less side effects too? I am not from a medical background, sorry if these things are pretty obvious in medical community


texts: What is the difference between a mechanistic and a statistical predictive model?

texts:
The simplest description of the difference between these two approaches that I have found are on this site who summarise the difference as:

Mechanistic model: a hypothesized relationship between the variables in the data set where the nature of the relationship is specified in terms of the biological processes that are thought to have given rise to the data. The parameters in the mechanistic model all have biological definitions and so they can be measured independently of the data set referenced above.

Phenomenological/Statistical model: a hypothesized relationship between the variables in the data set, where the relationship seeks only to best describe the data.

Could someone exemplify this difference with a short example. I have used and understand the principals of a statistical model (multiple regression etc) but haven't come across any simplistic examples of a mechanistic model and I don't understand what the difference would be in practice.

Edit: I am leaving the question open for a week to see if anyone wants to create a very small 'MWE' of the two types to illustrate what the difference would look like in practice, if not I will accept Memmings answer


texts: Do low light levels during development affect the distribution of rods and cones in the retina?

texts:
I just can't seem to find any retinal development experiments that have been done using low light conditions. I am very interested in knowing if raising an animal in such conditions leads to a different distribution of rods and cones in the retina. Perhaps it would lead to a more uniform distribution that the skewed distribution that is normally found?

Any thoughts or pointers to resources would be appreciated!


texts: Reduce protein structure representation dimensionality.

texts: In my lab we are trying to extract spatial features from protein structures. The software we develop makes use of CUDA for all heavy number-lifting, thus we are limited by the GPU's memory (12GB). Using standard voxel-based 3D-representations proved to be too memory hungry, hence we are trying to find a way to reduce the dimensionality to 2D, while preserving as much spatial information as possible. Our absolute goal is to preserve spatial colocalisation of different chains and secondary structures, to understand how important that is during folding. Standard techniques, such as PCA and PCoA on euclidian distances between amino acids, seem to preserve too little information on chain folds. We believe there should be a better way of doing that, but, having little experience in structural biology, we struggle to find any relevant work regarding this issue. Can you recommend any methods or relevant readings?


texts:
I am trying to understand the formation of embryonic disc for human and chick so the following question is related to here about formation of embryonic disc.

I had thought that the amniotic sac forms only from embryonic disc in humans, particularly of lateral mesoderm and ectoderm of embryonic disc. However, my thought seems to be wrong as my professor says that amnion form only for birds from embryonic disc, but from many different parts besides of embryonic disc for human.

What, besides the embryonic disc, forms the human amniotic sac?


texts: Can humans breathe an Argon-Oxygen atmosphere, where Argon substitutes the inert Nitrogen gas which currently populates our atmosphere? I didn't quite know which forum to stick this one in; I put it here because I only want to know if such a mixture of gases can be feasibly inhaled, without the prospect of early death by some physiological component.


texts: Origin, or source, of rhesus negative in human blood

texts:
This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few (~15% of all) humans have it, and most of those seem to be European. Looking just a little further, I found a bunch of crackpot-looking sites that try to explain how people got Rh- blood, and what weird abilities they possess as a result.

I managed to find one site that seemed at least less laughable, which suggested that interbreeding with Homo neanderthalensis (or possibly Homo sapiens neanderthalensis, since the site seemed to indicate that there was some question about how different H. s. sapiens were from H. neanderthalensis) might have accounted for the introduction of the condition.

It seems that from more reputable (medical) sources, the only difference between Rh+ and Rh- is that complications can arise during pregnancy if the mother is Rh- and the fetus is Rh+. Indeed, most sites (e.g., WebMD) seem to explicitly state that there are no other differences of note.

I am not a biologist, or an anthropologist, or a life-science kind of guy at all. However, as a computer scientist, I like to think that I have both an open mind but one which demands scientific and/or logico-mathematical evidence for claims. Lots of the pseudo-scientific, paranormal, etc. theories on the web I basically dismiss out of hand, as explanations which are almost certainly fantasies, but most definitely baseless and untestable.

My question:

  What, if any, is the current scientific understanding of the origin, or source, of rhesus negative blood in human beings? Do individuals with Rh- blood have any common (in a statistically significant sense) characteristics or health issues, aside from the issue with pregnancy and tending to be more European than not? Is there anything to continuing to look into this?

For context, I got started down this rabbit hole while looking into different dieting strategies, and found the "blood type diet". Just as an aside, I don't think there's a lot of merit to that diet... sounds like a fad thing. Any sources or information or help on this subject are appreciated.

EDIT:

I have been looking a little more, and I stumbled across a paper entitled, "The influence of RhD phenotype on toxoplasmosis and age-associated changes in personality profile of blood donors" which looks at the effect of the Rh- trait on personality changes caused by toxoplasmosis (if you Google the title, you should be able to download). Using Cloninger's and Cattel's personality factors, they seem to show a variety of things, including (a) personality differences between Rh+ and Rh- individuals not affected by toxoplasmosis, and (b) different reactions to prolonged toxoplasmosis affection in Rh+ and Rh- individuals.

I didn't even know that parasites could affect your behavior; that seems frightening on the one hand, but on the other, it's fascinating if it's for real, especially since the incidence of toxoplasmosis is not insignificant in most people. Anybody who knows anything about this or who reads the paper and can help me understand what it's saying would be doing me a great favor to answer/comment/chat. Thanks!


texts: Why Did 6 Great Ape Species Survive But Only 1 Hominid Species?

texts:
My dad asked this question when I explained some circumstances surrounding Homo sapiens survival against all odds.

We know there is only one hominid species left in the world, Homo sapiens. We also know that there are only 6 other species of great apes left: 2 species of chimpanzees, 2 species of gorillas, and 2 species of orangutans. These 7 species are the last remaining in the family Hominidae.

All the other hominids besides Homo sapiens died out tens of thousands of years ago, and we believe the reason our ancestors survived is because we were more "adaptable", meaning we were not restricted to a single environment but could survive in many others. This is the reason we later spread out all over the world, and probably why we gained "sapience" and are able to contemplate these grim circumstances.

At one point, following the eruption of the Toba volcano 70,000 years ago, there were between 1,000 and 10,000 mating pairs of Homo sapiens left, though there may have been other hominid species alive at the time. My dad asked, if the hominids faced such grueling environments and all but a few died, why did the great apes fare any better? Why are there 6 extant non-human Hominidae species left, but only 1 hominid species?


texts:
How does the ebola virus attack and how do some people get away with it? Normally any virus would attack a cell with some kind of receptors and some kind of lock and key mechanism entering the cell and then multiplying.

What happens to the virus if a person manages to live through it, does the virus die and is thrown out or still remains inside the host?

I am not sure about a normal virus attack i tried to explain please correct on that also.


texts: What is the scientific name of this parrot?

texts: I found this parrot at Nehru Zoological Park which is located in Hyderabad city of India.It's head to tail length is between 30cm-35cm.Can anybody tell me the scientific name of this parrot?


texts: How the glycogen accumulate intracellularly in the reversible cell injury?

texts: As we know in reversible cell injury as the most common cause is ischemia decreases oxidative phosphorylation which decrease ATP & increase anaerobic glycolysis which depleting glycogen !!? But one of the intracellular accumulation in addition to lipid , hyaline, pigments and calcium is glycogen So how this occurs ?


texts: I am looking for an alloy with low melting temperature (< 350°C) which is not toxic when in direct constant contact with skin, food and overall in domestic environment. My application is a solder that can be used for soldering a ring.


texts:
I have found this small bug on the wall in my bedroom, and have been trying to figure it out what it is for months.
There are more of this kind. They are tiny, I can't see how they look like with bear eyes. I can only see their proper shape by zooming in. I have seen them on my wall, in my drawer and on paper tissue.
I live in England in a very humid, dumpy flat.
I have also found bites or allergic spots on my body, but don't know if this bug causes it or something else.
Any idea what it is?


texts: Olympic's epidemiological impact on Zika?

texts:
I've seen a lot of fear mongering, misinformation and overall general panic concerning the zika virus surrounding the Rio Olympics. However, little has been said about the actual epidemiological impact of these Olympics concerning zika.

I would assume that sending hundreds of thousands of people into this 'zika hotspot' and then having them return to their home countries will likely only accelerate the spread of this virus. I understand that Zika has been present in other tropical parts of the world for 50+ years, but the South American strain has had a higher incidence of more dire effects.

My question:

Has anyone actually modeled how these 2016 Olympics will impact (likely accelerate) the spread of this dangerous viral strain throughout the world?

I know the CDC and WHO have people working on this, but I haven't seen any direct reports or evidence of such work. I know it's difficult to create too accurate of a model due to the lack of knowledge about other mosquito species' abilities to become carriers, so I would assume that if a model does exist, it's likely just using Aedes species as the main vector.

Regardless, if anyone knows about epidemiological modeling being done about the Olympic's impact on the spread of zika, please provide some resources.


texts:
I have seen the term "mouse LS cell" used in several papers now, but I haven't found an explanation for the origin of these cells (for example, this paper).

What are mouse LS cells? What is their origin (besides coming from mouse!)?


texts: Can memory be improved with mental training?

texts: I am a man in his mid thirties, but I already have a pretty bad memory. (I have always had a bad memory.) I can remember certain kinds of facts and music very well, but when it comes to words or even random  stuff like how did I fix a particular issue when I last encountered it, my mind goes blank. Lack of sleep aggravates it even more. Lack of sleep also severely retards my language skills because I can't recall any vocabulary. Other than the memory issues I am a healthy person. Is there anything I can do to improve my memory?


texts: I want to extract RNA from various tissue samples, liver, gut etc, in different treatment groups. Due to the large amount of samples I will extract in sets. I am wondering, in reducing the potential for contamination whether it will be better to extract by tissue type or by treatment?


texts: How plausible would it be for animals to normalize the birth of monozygotic twins in their reproductive cycles?

texts:
I'm currently trying to develop the world of a sci-fi story I'm working on, and a concept I've thought of adopting with the environment and characters is a common breeding system where identical twins (or sometimes not, asymmetric twins from the same egg have also been under consideration) are a commonplace byproduct of the world's evolution.

I'd like to know the plausibility of this. My idea is for two twins to be born with natural, pheromonal connections between each another. The sexual organs of the twins would be the same, thus preventing immediate inbreeding. I'd also envisioned [most] twins consistently having lifelong reliance on one another. i.e. I also want to know how reasonable it would be to expect them to coordinate efforts in the acquisition of food and evade potential predators. As for mating, I thought if they shared the exact same DNA there would be less ingrained concern over which gets to spread its genes. Would this be accurate?

Thanks in advance for anyone that tries to answer me. I'm doing what I can to keep things in the realm of reality, so it'd be much appreciated to know whether or not the universe I'm creating has a strong enough footing in the real world.


texts: How does cancer of the larynx (laryngeal cancer) affect the respiratory system?

texts:
The larynx is part of the respiratory system and is responsible for producing sound (our voices). My question is how cancer in the larynx (voice box) affect the respiratory system overall? I appreciate any answer, but if it's not too inconvenient, please don't use too complex terminology (I'm in grade 10 Canada).

Thanks


texts: What do you mean by the non cellular matrix in which connective tissues are embedded?


texts: Can PCR tubes be made of different materials than plastic?

texts: Does it matter if I replace the PCR tube (usually made of plastic) with another material like aluminum, glass, or something similar?


texts: How do antibiotics combined with a non-Western diet affect weight loss?

texts:
Wikipedia describes a Western diet as:

  ... higher intakes of red and processed meat, butter, high-fat dairy products, eggs, refined grains, white potatoes, french fries, and high-sugar drinks.

In the following article there is information about research done that suggests mice eating a high-fat diet while taking antibiotics become obese:

Scientific America: How Gut Bacteria Help Make Us Fat and Thin

I was wondering whether there has been any similar study to see what happens to obese mice or humans that take antibiotics while eating a non-western diet such as the Mediterranean diet, which this Guardian article suggests does not cause weight gain?:

The Guardian: High-fat Mediterranean diet does not cause weight gain


texts: Some of the greatest inventions of my lifetime have been from looking at nature and copying. I found out tadigrades in outer space have the ability to repair their own DNA when exposed to radiation thousands of time higher than what it would take to kill a human being. Can the tardigrade's genome be mapped and the section of DNA responsible for repairing radiation damage be duplicated? Would that be a good thing? Could a stem cell with that section of DNA make our astronauts safer?


texts:
There is something strange growing straight out of the glass windows at work. They look like hairs, about half an inch long, and each have a white spot on the tip of them, slightly weighing them down. I first saw a few of them a week ago, and now there's about twice as many. They don't move, except when blown in the wind, etc.

Here's just a few of them, the first ones I discovered:

They haven't budged from this spot since I first discovered them, but more have appeared surrounding them. This is located in Louisville, KY, USA, and there has been some hot humid weather lately. This particular area where they're growing is in the shade and a partial roof, so these windows rarely ever get rained on.

A friend hinted that they might even be insect eggs.

What are these things? Fungus? If so, what kind?


texts: Screen brightness for reading in dark room

texts:
While searching online I did not find any conclusive article on whether it is good or bad for one's eyesight to read on a computer screen in a dark room. Most mention that it will cause strain that will go away after some rest (sleep).
My question is does reading in dark room has any long term effect on one's eyesight and what screen brightness setting (low of high) should one prefer if trying to read in a dark room?


texts: Why is the opposite of plantar flexion called "dorsiflexion"?

texts:
Why is the action of flexing the foot so that the toes move anteriorly/superiorly (i.e. in the direction opposite that which they move during plantar flexion) described as "dorsiflexion?" In the same vein, why is the top surface of the foot called the "dorsal surface?"

If anything, the action opposite to plantar flexion moves the foot in the ventral direction, doesn't it? And surely if you've ever seen a human in the anatomical position, you can see that there's nothing dorsal about the top surface of the foot - it's superior, perhaps, but by no means dorsal.


texts: Is it true that there is a spider that eats parasites from caterpillars

texts: I think I once saw a video of a caterpillar that could get infected by a parasite, and could die of that, unless a specific kind of spider would eat the parasite, and so once the caterpillar is infected it goes looking for that spider. I can't find that video anymore though, nor any reference on this, so I'm beginning to doubt myself. Does this behaviour really exist?


texts: Can Western Blots be used to quantify the activity of a protein?

texts:
I am new to Western Blot analysis and I have recently done my first two. I am studying a phosphoprotein (a protein kinase) that can be both activated and inactivated via phosphorylation at a specific amino acid residue. I have labelled my membrane against the active and inactive forms of my protein of interest (using phosphospecific antibodies), as well as the total protein (using pan-specific antibodies).
I know that Western Blots are used to quantify the expression of a protein (i.e. how much of a specific protein there is in a sample). But I was wondering how they can be used to quantify the activity (e.g. how functional the protein is) of a protein, e.g. how can I measure/determine whether my protein is more active/inactive in my treatment samples vs. control?
For example, I have normalised the integrated density values for my active protein bands against the integrated density values for my total protein bands. Then I have calculated the fold change in protein level for my active protein in treatment samples relative to control.
If I have observed that the fold change for my active protein is reduced by 40% (as an example) in treatment samples relative to controls, would this be sufficient data to say that the activity of my protein of interest is reduced in treatment samples compared to control?


texts: Can a schiff base stabilize the transition state and form an intermediate as in covalent catalysis with a substrate in the same reaction? Basically I'm wondering if a schiff base creates a ping pong reaction.


texts: Does chromosomal crossover result in a mutation?

texts: Is chromosomal crossover considered a mutation? Would this be a large-scale mutation?


texts: Does the plant cell vacuole form by the invagination of the cell membrane?


texts: Blood and plucked-feather sample storage

texts:
This next field season I will be collecting both blood and feather samples and I wondered how best to store the samples. The blood samples will be used for microsatellite and/or SNP analysis. The feather samples will be used for genetic sexing and/or microsatellite analysis.
Feathers: can these be stored in envelopes at "room" temperature? I've seen mixed answers in the literature. They are plucked feathers and so may have a bit of blood or tissue at the tip. If they are used for microsatellite analysis, I want to ensure this DNA is not degraded. I will be storing them frozen at my field site, but our partners at other sites may not have access to freezers.
Blood: we will be collecting blood into capillary tubes. I have a few Whatman FTA cards, but not enough. So I'm planning to freeze the blood in the capillary tubes. Are there better options than this? I'm planning to use non-heparinized tubes. Out of curiosity, has anyone used blood from FTA cards for microsatellite or SNP analysis? Can I expect sufficient DNA quantity and quality? Bird DNA is nucleated, so I should get more bang for my buck (volume-wise).
I appreciate your help!


texts: At what age does the mouse skull stop growing?

texts:
Unless otherwise mandated, neuroscientific research on mice is done with ~7-week old animals. There is a sort-of mantra that at this age their skulls stop growing.

However, recently, I noticed a rather robust difference in how I have to place ~4-month old mice in a scanner versus 7-week old ones. I am pretty sure this is due to skull size, since I am fixing all my animals relative to the ear canal, and there should be no fat/hair accumulation in the inner ear. Also, if there would be, I am quite certain I would feel it.

This made me try to look up the source of the 7-week recommendation, but up until now I found nothing. Do you know whether it is correct that the mouse skull "stops growing" at 7 weeks of age, and if so, what studies support this observation?


texts: Can viruses replicate in a cell that's already dead?

texts:
Suppose a virus randomly lands on a cell that's just lying around. This cell may have just recently died, or died a while ago. This cell may also be part of tissue of a dead organism.* Does the virus know that cell is dead? Would it attempt to inject its DNA into the cell?

*If it's a single cell, not part of a tissue, I imagine a "dead" cell would be lysed, so a virus landing on a "single dead cell" wouldn't happen - pleae correct me if I am wrong. So I'm asking how it would be for a dead organism because we can still see those dead tissues ..


texts: why do chaperones bring protein into mitochondria? why would mitochondria need protein?

texts:
Sounds trivial? Please help to sort out. I saw this picture while looking at dehydration reactions and cell revision.

And proceeded to the reference web page.

  Protein Folding and Processing in the ER: Various changes occur to proteins in the ER.
  Chaperones and Folding: Polypeptides must assume the correct folding pattern in order to function properly. The correct folding of a protein is mediated by chaperones (they also are proteins--chaperones are abundant in the ER lumen). A completed polypeptide will assume the correct folding pattern spontaneously, however before translation is complete, it could assume an incorrect formation or it could aggregate with other partially made polypeptides. To prevent this, chaperones in the ER (and cytosol) bind to the nascent polypeptide and keep it from interacting with anything until the polypeptide is completely synthesized. (Chaperones bind to polypeptides destined for mitochondria then release them as they pass through the mitochondrial membranes. Chaperones on the inside of mitochondria bind until these polypeptides have completely entered.)

With regards to protein synthesis and folding, this kind of info is not in my textbook. Not in couple of the online open textbooks either. I even search for where do protein fold? to find out if there was a relationship. It doesn't say protein fold in mitochondria and turns out it's a question most scientist are looking for answers.

For whatever protein synthesis I have learnt so far, there was no mentioning of protein strands going into mitochondria but mitochondria as a power houses. What's going on here?

Why would a protein go into a mitochondria? How does it exit and where to?


texts: Difficulty in developing certain vaccines

texts: I have a college level background in Biology, say at the level of Campbell. I am very curious to know why it's extremely difficult to develop vaccines for certain diseases. Two cases which I am really interested in are Malaria and AIDS. It would be great if someone can give a brief sketch of the major issues being faced without getting into extreme technicalities. Thanks in advance.


texts: How Behind is the Human Mind (Latency of the Senses)

texts:
I would like to know if there is any research into the latency of human perception.  Particulary:

What is the minimum time for various inputs (vision, touch, sound) to be recognized by the conscious mind?
How different are these times?  (Loud sound vs sense of touch in your toe)
Given the above, is there a number we can put on how many milliseconds behind reality the human mind is?


texts: Doubt in a multiple choice question involving cell organelles

texts:
Find the odd one out and state the category of the rest.

  Chloroplast
  Mitochondria
  Nucleus
  Grana

Now my answers are :

1st possibility : grana

Category : presence of DNA in others

2nd possibility : grana

Category : all others are cell organelles

Are their any more possibilities and are my answers reasonably correct?


texts: Can organisms like Noctiluca be commercially exploited?

texts:
Scientists think that Noctiluca flashes to startle or scare away its predators. The bioluminescence might also attract bigger predators to eat Noctiluca’s predators, just like a burglar alarm that alerts the police to come to someone’s house to catch a robber.
 It takes energy to make the chemicals that allow them to glow. It would be a waste of that energy to glow during the daytime
But the question is whether we can commercially exploit this for human welfare??


texts: Is this a termite wing or flying ant wing

texts: I saw this on the bottom corner of my pantry in the Washington DC area. I can't tell whether is termite wing or something else. The wing is 3/4" long.


texts: What is this red mushroom with the "inverted" cap?

texts:
Picture taken on 29 March 2020, Czech Republic (Middle Europe). The cap is red, and its shape is "inverted". It is quite tough, first I thought it was a piece of plastic, but apparently it is growing from the ground.

What is the mushroom - if it is a mushroom :) ?


texts:
I have been taught in school that aluminium is harmful for brain.
Thus sour meals should not be cooked in aluminium pots and it is unhealthy to add lemon juice to tea while there is teabag in the cup, as acid facilitates aluminium release.

The only safe limit for aluminium intake I know is FDA pediatric limit for parenteral sources (5 μg/kg bw/day). I know no research the limit is based on, but I have read an abstract of a paper claiming it was impossible to comply with the regulation in patients weighting less than 50 kg.

Nowadays aluminium ions are present in several vaccines, which are considered safe to be injected intramuscularly in infants despite despite being  nowhere near the FDA limit.

I'm quite confused how strict should I be in avoidance of aluminium intake (especially dietetary intake - which I expect to be far less effective than parenteral).

[EDIT]

It seems aluminium is also a component of some antacids which are used to treat heartburn.
Does it mean aluminium consumption is safe at general, or it is just considered to be less harmful than acid indigestion (there are some side effects  mentioned - but nothing about accumulation in the brain)?


texts: If gene differs between chromosome pair does individual get a mixture of protein shapes?

texts: Do diploids such as humans end up with a mixture of two different shaped proteins where the appropriate gene is expressed differently in the two halves of a chromosome pair or is there some governing factor that dictates that only one of the alleles is ever used to direct protein synthesis?


texts: Are there any mammals whose males can feed with milk?

texts: Are there any mammals whose males can feed the offsprings with milk from the breasts?


texts: Potential evapotranspiration constant for trees in the area of London

texts: I am trying to find the ET0 (Potential evapotranspiration) under the climate conditions of London (UK) and Coimbra (Portugal) for each month. From what I understand these data is available in the FAO's website but I was struggling to find it.


texts: How can myoglobin be responsible for the red color of meat if it is located in the cytoplasm?

texts:
How can myoglobin be responsible for the red color of meat if it is located in the cytoplasm, as the visible part of muscle cells is the membrane (at least as I believe)?

Sources:
https://en.wikipedia.org/wiki/Myoglobin
http://jeb.biologists.org/content/207/20/3441


texts: What is the actual seed in the fruit of the macadamia tree?

texts:
Fruits of the macadamia tree are woody, hard shells, very difficult to break and have an edible part inside. Culinary people call them nuts, but in botany, they are not nuts, just fruits.
If I take a typical macadamia fruit (intended to be eaten, but sold still in shells), crack the shell, how do I find what is the pericarp, mesocarp, endocarp and what part is the seed?
What are the anatomical parts of the edible and inedible layers of the macadamia tree fruit?


texts: What is the difference between protein translated by a free ribosome and protien translated by a ribosome attached to endoplasmic reticulem?

texts: There are protiens translated by free ribosomes and proteins translated by attached ribosomes.  But how do these two types of protein differ from each other? I am just talking about a eukaryotic cell. I know that proteins made by free ribosomes do not have a covering but proteins made by attached ribosome gradully have a vesicle around them but I am not able to understand what difference in use does the vesicle make? (I am new here so pls forgive if there are mistakes in my question)


texts: What is the mechanism of folic acid deficiency and neural tube defects?

texts: I am having difficulty finding the mechanism by which folic acid reduces the risk of neural tube defects. I know that it does so, but what in particular actually occurs with folic acid deficiency to cause the neural tube defect? Is that completely unknown and merely a strong association, or is there a putative mechanism?


texts: What is two-start or zigzag model of 30 nm chromatin fibre?

texts:
I read some webpages describing the two-start model but could not get it. I'll be obliged if someone helped me understand the topic.
The websites I have been through are:

1.http://www.nature.com/nrm/journal/v13/n7/fig_tab/nrm3382_F4.html

2.http://www.mechanobio.info/topics/synthesis/go-0006323

3.http://www.fastbleep.com/biology-notes/41/118/1272


texts: Length of dispersal flight of European spruce bark beetle?

texts: I'm interested in length of dispersal flight of Ips typographus. I can barely find some information about dispersal distances, height of dispersal flight, but not at all information about how many days does it takes for one beetle to find suitable host in average? The only information I found is that it is highly variable (Forsse, E., & Solbreck, C. 1985. Migration in the bark beetle ips-typographus duration timing and height of flight. Z. Angew. Entomol. 100 (1). 47-57). I also know that it is weather dependent but this won't help me... thank you !!


texts:
How can one find the information of a protein environment ph from its PDB id?
Can one assume the ph to be the same as its cellular location?


texts:
I found this insect in my own courtyard in the city of Pamplona, Navarre, Spain; during mid-February. My courtyard is never directly exposed to sunlight and is always cold, poorly lit and humid. It was 15 millimeters (0.6 inches) long when it kept its body still and straight, without counting the antennae which were 3 millimeters long each (0.1 inches). Its abdomen covered 2/3rds of its body length, and it constantly curled up and down. It also had a pair of wings, with the beginning of each partially covered by a shorter, brown, wing-like structure. To the exception of those brown coverings, its entire body was jet black and was slightly shiny.

I kept it in a test tube and put it with a spider that was almost its size. It was undisturbed by the spider and even approached it often.

Update: It dismembered the spider in less than a day.


texts: Are there genetic causes underlying the difference in circumference of the upper arm and foream?

texts:
Is there any genetic reason for the difference in size between the upper arm and lower arm (i.e., the forearm)?

In most women, it seems that the upper arm is larger in circumference than the forearm. However, in males it seems to vary - some men (like myself) have an upper arm with a diameter smaller than their forearm, while for example in body builders the opposite may be true, as they often have large biceps.


texts: Cell-level selection and inheritance of acquired mutations

texts:
I was reading about different levels of selection in Ridley's Evolution textbook (chapter on units of evolution) and saw that some organisms e.g. carrots are not Weismannist i.e. don't have separate somatic and germ lines and can make offspring with their somatic cells, and that this can in theory lead to cell-level selection because cell lines that outcompete others have a greater chance of leading to offspring and thus will be selected for. I think mutation that arises in a cell during the organism's lifetime and causes it to proliferate counts as an acquired mutation, but I've also read a lot that acquired mutations/characters aren't passed on a la Lamarck.

Is this a case where acquired mutations are passed on, and how does that fit with the usual concept that acquired characters aren't passed on? I know gene, individual, and kin selection are much more prevalent and Ridley says the cell-line selection idea is just theoretical, but what would this mean if it occurred?

Thanks :)


texts:
In the Wikipedia article on nuclei one reads:

  "The neurons in one nucleus usually have roughly similar connections
  and functions."

I read this as "a nucleus usually is roughly homogenous", i.e. contains a small number of neuron types, distributed roughly equally and with a roughly homogenous connectivity pattern.

But it is also stated:

  "A nucleus may itself have a complex internal structure, with multiple
  types of neurons arranged in clumps (subnuclei) or layers."

What I would like to know:

Is my reading correct?
Are there really more nuclei of the more simple (homogeneous) type than of the more complex type?
Which are prototypical examples of both of the types (more simple and more complex)?
Which are the greatest nuclei of "the" simple type (with respect to volume or number of neurons, taking "simple" with a grain of salt)?


texts: why thymectomy doesn't lead to humoral immunity deficiency?

texts: thymus is a place where T cells educate. in all textbooks it says if you remove thymus you will have cellular immunity deficiency. so in that case you should also be humoral immunity  deficient,then why it is only the cellular immunity which is ruined?


texts: Is the human biological clock genetically programmed or learnt?

texts:
Argument favouring learning:
A newborn sleeps for 20-22 hours. But overtime (s)he learns to focus sleeping time to night time, according to his or her needs and family needs. Some sleep from 1 am to 7 am, some from 11pm to 5 am. So it is learnt.

Argument favouring a genetic origin:
Somewhere I read (I don't exactly remember the article) where it was told that the biological clock is not of 24, but of 25 hours. This means that the synchronisation is not maintained with the earth. If it would be learnt, then why is it not in synchrony with the world?


texts: How is the reflectance spectrum of solids measured?

texts: I was reading this question about autumn leaf colors. One of the answers refers to an article by Archetti et al. In the article, box 4 (page 5) shows the reflectance spectra of leaves of different color. How is the reflectance spectrum of such solid materials measured? There was a recent question about spectrophotometers but it appears to assume the sample is in a liquid form.


texts: The three bones in the middle ear -- the malleus, the incus, and the stapes-- play a role in transmitting sound waves to the inner ear (the cochlea). I understand that the malleus is the bone closest to the tympanic membrane (and therefore the primary receiver of information) and I understand that the stapes is responsible for transmitting the information to the cochlea... so why even have an incus bone?


texts: Pearl formation process: what is it called? How does it work?

texts:
I have heard a pearl is a disease of oysters.
Astonished by the statement, I searched a bit [1] and I discovered that  it is really a protection mechanism of the oyster.
I know this defense mechanism is not unique in nature. E.g. humans can isolate foreign bodies (this happens with not-extractable bullets), as well as bees propolize foreign bodies if they can't eject them.
What is the process, the ability of those organisms, called?
How does it works? E.g. how organisms recognize foreign bodies other than other things?

[1] https://en.wikipedia.org/wiki/Pearl


texts: What is the genetic explanation for gall forming in erythrina by gall wasp?

texts:
http://www.cabi.org/isc/datasheet/46220

Gall wasp  layed egg in the stem of the erythrina variegata,  the larva make gall, I like to know how the gall formation occurs in erythrina variegata


texts: How to tell petiole apart from stem? Is it by the rule that there is usually a pair of stipules at the base of a petiole?


texts: During starvation, does the human body do anything to prioritize which organs receive nutrients?

texts: When food is scarce, the body slows its metabolic rate to conserve energy. Are there any other systems or processes that prioritize which organs receive nutrients?


texts: More specifically, if a human subject was exposed to, say, a human cancerous cell line (via intravenous injection or through an open wound, for example), is it possible that they would develop any conditions associated with the cell line?


texts: Does the brain and the body use the same energy source (glucose/ATP)?

texts:
I've heard that the brain consumes quite a lot of oxygen and energy, compared to the rest of the body. What I'm interested in is if this is the kind of energy and oxygen that the rest of the body competes for?

For example, does running divert resources from the brain to the
muscles, leading to decreased cognitive performance?
Does digesting food divert resources from the brain to the gut?

Does the heart rate or blood pressure have anything to do with how much resources, like oxygen and energy are available to neurons?

Thank you for your input!


texts:
Why do we feel asleep at night mostly?
 I tried not to sleep but I could not resist my sleep at night.


texts: What are this designs which I found on curry leaves?

texts:
Curry leaves is the plant name where I found designs, but what are the designs present on the leaf?

Location: Argentina


texts: What are the units of the band intensities in a western blot image?

texts: I have done a Western blot and I am measuring the band intensities in Image J. Using the rectangle tool, I have outlined the band and then calculated the area and the mean intensity of the band. I have then calculated the total intensity of the band by multiplying the area of the band with the mean intensity. I was wondering, what are the units of the band intensities? Are they in arbitrary units? Any insights are appreciated.


texts: So I am taking a new class at my institution called Theoretic Nuclear Thermochemical Pharmacology, (I know big name, it's an elective from a real pioneering fronteirsman in our department :P) and I am curious about the metabolism of gabapentin and how this might relate to thermochemistry?  I am curious how this drug metabolizes in the liver and how it neurochemically alters the brain such that it reduces mania in patients that are bipolar and may also have mood disorders.  Any kind of relevant literature would be appreciated, something to guide me in the right direction.  I mean I understand liver metabolism and what it does but its relation to mania and how it's thermochemical still boggles me.


texts: What is the need of mucilagenous coating in pollen grains of aquatic plants?

texts:
I'm a high school student from India and here in our prescribed biology book(NCERT), it is written that pollen grains of aquatic plants have a mucilagenous coating to protect them from wetting.

My doubt is that they already have the most resistant chemical, the sporopollenin, on their exine to protect them. It cannot be degraded by acids, enzymes, high temperature, alkalis. Then what is the need of another layer of mucus to protect even the most resistant of nature's chemical? Or is it that sporopollenin is absent in aquatic plants? I cannot find anything good to satisfy my doubt out there on Google.


texts: Why does pyruvate from lactate and pyruvate from other sources follow different pathways in gluconeogenesis?

texts:
My teacher taught me in a lecture that PEP forms from Pyruvate by two ways, based on their sources, that is -
1. If the Pyruvate was from lactate (by lactate dehydrogenase action), it gets shuttled into mitochondria and is successively converted to OAA and PEP, by enzymes PC and PEPCK(mitochondrial) respectively. This PEP is then shuttled to cytosol for rest of gluconeogenic steps to take place.
2. Whereas, if the Pyruvate was from any other source, it is shuttled to the mitochondria, where it is converted to OAA by PC. It is then shuttled to cytosol by malate shuttle and then converted to PEP by PEPCK (cytosolic).
Why the difference in mechanism?
Please correct me if any of these steps are wrong.


texts: Embryonic cells, when can you detect them in vivo? (In order to do whole genome sequencing)

texts:
I was wondering, when is it possible to extract cells (humans or mice) in order to sequence them and detect diseases.
Extra: Urine of the embryo in humans is excreted in the 16th week, so I guess that then it's possible to extract some embryo cells.

EDIT
In other words, when is it possible to grab enough DNA to know the full genome of the embryo without damaging it?
In order to sequence it and avoid most genetic diseases and regulate the weekly abortion limits.

Thanks