texts: How are hereditary neural circuits created in the brain during early development?

texts:
Whilst our experiences shape the specifics of our brains throughout life, we know that there are a lot of shared properties between us. We all share the same basic layout as, for example, the V1 cortex is always in the same place. Thus it is evident that whilst some of the neural development is experience-dependent, some of it is hereditary/genetic or "hard wired".

It would seem to me that the extent to which the brain is "hard wired" depends on the species. Humans seem to have a lot more room for specialisation in life, whereas some animals don't exhibit much individuality, tending to follow very regular behavioural patterns that have no doubt evolved over time, subject to natural selection.

I have read up to some degree on how experience-dependent development works, but have been largely unable to find any detailed research into how experience-independent development works. That is, how does DNA encode these "hard wired" neural circuits?

Furthermore, the human brain contains some 100 billion neurons. If I assume that maybe 1% of them are "hard wired" into circuits from birth, that's still a billion neurons, each with several connections to other neurons that need to be somehow coded into a DNA sequence which only amounts to a couple of gigabytes worth of data. So how is the complex structure of these "hard wired" (experience-independent) neural circuits encoded in such a limited amount of DNA? How much of the brain is actually hard wired in this way and how much is open to experience-based development? Am I right in associating this process with the phenomenon of "instinct", that is, "hard coded" behavioural patterns in animals which appear to be hereditary?

Is there a name for this field of study? Specifically the study of how neural circuits are generated in the earliest stages, to lay down the high level structure of the brain before experience-based development can take over?


texts: Can you still contract a disease after being vaccinated and be able to spread it?

texts:
I assume I know the answer to this already but wanted to confirm before I respond to someone that appears to be arguing that vaccines don't make you immune (they only stop your symptoms?) - but you remain infectious?:

She also doesn’t realise that if a vaccine works like she believes then the vaccinated would have less symptoms which in result offers more chance of spreading it. literally how covid spreads so fast now. “no or mild symptoms“ to most. Thats the sole reason it spreads so fast. So technically getting vaccinated is more dangerous in spreading disease than someone that gets sick and stays at home.

Edit: This question is about vaccines in a more general scope as that was the discussion at hand, but if anything it would be more closely targeted at COVID-19, which I'm aware there is currently no vaccine for.
My understanding of vaccines in general is that they don't technically make you "immune", but they make you immune to the effects of the virus, because your body will already know how to beat it.
But in saying that, my assumption has also been that because you have somewhat of a immunity to it then if you get "infected" with the disease you aren't contagious to others.
Additionally, I assume getting "infected" with the disease and being protected against it's effects is different to being asymptomatic - both have no symptoms, but you are still truly infected with it if asymptomatic and can still pass it to others, it's just not affecting your body enough to give you symptoms.
Just thinking now, but if your body knows how to fight it off already, then maybe you are truly immune to it - just because it enters your body doesn't mean it infects you right? Your body knows how to fight it off before it does. Like, an attacker can enter your grounds and knock at the door, but your guards know how to fight them off before they enter the area of your grounds where they 'cause the trouble'.
...but on the case you CAN get infected with it, but it doesn't present any symptoms, are you still contagious to others?
Additionally, I'm not talking bout virus shredding here from getting a vaccine, I know all about that.
One would think the proof is in the pudding in that many diseases have all but been eradicated from the world because of some vaccines, but I argue with myself that if vaccines don't make you immune then perhaps these diseases have only largely seemingly been eradicated because most everyone has been vaccinated (with vaccination preventing you from the effects only, not getting infected?) - thus only appearing on the surface they have been eradicated, but they are still around, but just don't pose a health risk to those that are vaccinated?
So, primary question is, what is meant exactly by "immunity", can you still contract the disease and if so would you still be contagious to others?


texts: Generating custom human DNA sequences based on traits such as eye colour?

texts:
I'm wondering if it would be possible to create software (unless some already exists, but I couldn't find any) to generate human DNA (the base pairs on the double helix) containing genes representing specific permutations (eye colour, hair colour, etc.)?

Basically, something like the "character builder" from those "Saints Row"-style video games, except with actual human chromosomes, enabling you to essentially create a 'custom' human.

Of course, that is assuming that all human DNA has a common structure, and that the entire sequence can either be assembled from individual chromosomes, or by using a reference genome and modifying specific genes/chromosomes according to user input. Is this the case?

One setback here, of course, could be the number of bases in each chromosome, which ranges between 100 million and 250 million, and the (approximately) 23000 human genes - a lot of data to manipulate.


texts: Are redundant codons used in translation?

texts:
I am learning about redundancy in genetics and I came across this statement in my textbook:

  more than one codon for an amino acid means that some codons are redundant - the process of protein synthesis could function without them.

I understand that codons are used to make specific amino acids. Does the statement from my textbook mean that if there are two codons which code for the same amino acid that only one of the codons code for an amino acid and not both? I know the term reduntant means that in some cases - more than one codon can code for the same amino acid - but does it also mean that some codons are not used because another codon codes for the same amino acid?

Thanks


texts: Protein turnover can be measured by calculating the "decay" or loss of radio-labeled proteins in the blood, for example, but I am confused at how this calculation works. Wouldn't the radioactive isotope that you're using be decaying due to being unstable and not just due to protein turnover? Would you have to account for that in your calculations?


texts: Do any amphibians start their lives on land?

texts:
Most amphibians - at least, all the ones I know of - start their lives in the water (at least, after they hatch). They then spend time maturing before venturing onto land, where they can breed. The cycle than begins again.

Are there any cases where the reverse is true, i.e. a young amphibian starts life on land before venturing into the water as an adult?

Wikipedia hints that this may be the case, but fails to provide examples:

  Amphibians typically start out as larvae living in water, but some
  species have developed behavioural adaptations to bypass this.


texts: Why would Aspergillus Oryzae produce lactase when no lactose is present?

texts:
Studies [1] have shown that lactase is produced by A. oryzae when grown on wheat bran and spent beer grains.

Why would A. oryzae produce lactase when these substrates have no lactose?
In [1], it's shown that A. oryzae produces more lactase when grown on wheat bran vs when grown on whey, which has lactose in it - what might explain that?
Since lactose is found in mammals and is not common elsewhere, how/why could A. oryzae have evolved the ability to produce lactase in the first place?

[1] Bailey, M. J., & Linko, M. (1990). Production of β-galactosidase by Aspergillus oryzae in submerged bioreactor cultivation. Journal of Biotechnology, 16(1-2), 57–66. doi:10.1016/0168-1656(90)90065-j


texts:
I am studying the general use of models in biology in terms of methodology, applications, usefulness etc, and I would really appreciate any recommendations of some specific examples of models from any area in biology. Some examples are the logistic growth model or the Lotka-Volterra prey predator model.

It would be nice if you could shortly explain what the model is used for and why do you think it's an interesting case, and give a reference for further study.

Also any recommendation of books on model development and other meta-model questions in biology is very welcome. Thank you.


texts:
could someone please identify this insect? This photograph was taken in the Western Ghats of Maharashtra, India, near the town of Mahabaleshwar. Hemiptera was about as far as I could get using other online guides.

Thanks!


texts: What is the substance that tumors release that stimulates growth of blood vessels but suppresses its release from other tumors?

texts:
I'm currently in high school and I am working on a cancer research project. My project consists of a cancer, and different ways to treat it. I have a set of benign tumor and I was thinking of immediate way of treating it without using a drug like Taxol to destroy parts of the cell is to simply remove the tumor.

However, I remembered learning about a 1 1/2 years ago about a substance that tumors release to stimulate the growth of blood vessels towards them, but this same substance suppresses the release of itself by another tumor (hopefully this makes some sense). I made some drawings that are attached here:

Scenario 1: The 1st tumor in the blood flow releases an unknown substance, which promotes blood vessel growth, but suppresses the release of the same substance from another tumor behind it.

Scenario 2: The 1st tumor is removed, and now the 2nd tumor starts to release the substance, because the 1st tumor's release is not suppressing the 2nd tumor's release anymore.

Does anyone know the name of this substance, and can someone help me learn more about it? Thanks.


texts:
If there is an apoptosis shut-off mechanism of any kind, one could call it a null-apoptosis mechanism.

If this is possible, could there be a null-apoptosis inhibitor? Something that inhibits an apoptosis inhibitor?


texts:
We found this near Fort Pheonix in Buzzards Bay in Massachusetts. It gets long when its swimming (About 8 inches) and contracts when disturbed (2 inches).

Its head is shaped a bit like a diamond (like a cobra?). Its body looks fairly translucent and is ribbon-shaped.

Here's a short video: https://vimeo.com/240322590


texts:
How much does a typical biologist know about signal processing, machine learning, and (theoretical) computer science?

Coming from a neuroscience background where knowing about algorithms and computer science is a must, it seems to me that in biology there is much less cross disciplinary work. Though, yes, there are bioinformatics (but you only do sequence alignment and clustering?).

Anyway, given a typical PhD student in biology, how much does he/she need to know about programming, signal processing, etc?


texts: What is PDMS used for in microfluid models?

texts: When creating a microfluidic model using polydimethylsiloxane (PDMS), is PDMS used only as a stamp to lay proteins in coverslips or can cells be cultured in the channels or patterns created in PDMS?


texts: Cellular respiration in carnivorous animals

texts:
What is the equation for cellular respiration in carnivores as they don’t consume carbohydrates to break down into glucose in the following manner:

Glucose + oxygen -> water + CO2 +energy.

Do they (mammalian carnivores) primarily use ketones to produce energy without using glucose?

Does this mean that glucose is not the only energy source for humans/other animals?

Am I wrong in thinking that every source (protein, fats or carbohydrates) need to be convert into glucose for energy.


texts:
So in the video my instructor sent on viruses, he said that for lytic viruses, new viruses manufactured by the host cell could get out of the cell in one of two ways.

The new viruses would leave by exocytosis.
or,
The cell would be "ruptured" and the new viruses would "erupt out of the cell".

In the rupturing option, is the cell destroyed? The way he phrased it as well as his tone of voice brought to mind an image of the cell bursting and the viruses spilling out....but the diagram showed a little gap in the cell membrane, and the viruses leaving from that one exit point.

Which is more accurate?

Thanks!

evamvid


texts: Can anyone explain the idea of anodic nerve stimulation?

texts: Nerves get stimulated under the cathode, according to the conventional current direction. But in some research, it is said that anodic stimulation or anodic current stimulation can activate neurons. How does it occur physically? The picture below shows the two types of stimulation, but I can't get it.


texts: What happens to an ant colony when the queen dies?

texts: Does the colony collapse? Do workers keep following the last orders? Or can future queens replace the dead one? I'm guessing this might also depend on each specific sub-species.


texts: Does ChEMBL have a specific definition for what they mean with "Max phase for indication"?

texts: ChEMBL lists various properties at pages for substances. I would like to copy some of the data that resides under "Max phase for indication" over to Wikidata. For that it would be good to know the exact definition that ChEMBL uses for "Max phase for indication". Unfortunately I can't find it on their website. Is a definition available somewhere?


texts:
It was found on the shore of the Ohio River in Kentucky. It is very hard, like bone, and feels hollow but does not rattle.  It is translucent.  I do not think it is skull of a water fowl even though the blunt end appears beak-like. I cannot figure out if it is plant or animal.  It was found in an area where arrowheads were found.
It appears to be hollow. I do not believe it is a shell since there is no margin or growth lines. It appears to be shriveled or desiccated.


texts: How do enzymes not change the overall energy change of the reaction they're catalysing if they lower the activation energy?

texts:
Based on the Induced-Fit model of enzyme action, enzymes catalyse a reaction by lowering the activation energy of a single forward reaction over and over. But I read that enzymes don't change the overall energy change of the reaction $(\Delta H_{solution})$ they just speed up the reaction.
How can enzymes reduce the activation energy of every forward reaction but still not affect the $\Delta H$? $\Delta H$ is sometimes called change in heat because it is measured in Joules and it's either endothermic or exothermic (this bit is chemistry).
I'm a highschool student and I'm just trying to find out how the required activation energy doesn't affect the energy change for the whole reaction.


texts: Why majority of synthesized mRNAs are halted at Nuclear Pore Complex?

texts:
I was reading about mRNA export process. I came to know that only 36% of synthesized mRNA transport events at Nuclear Pore Complexes(NPC) of the nuclear membrane get successful in crossing to the cytoplasm. I have heard that transcription machinery is a highly accurate one and so why would NPCs want to regulate mRNA transport like this?

Is NPC acting as a quality checker? Are there any errors mRNAs facing in between the transcription and meeting NPCs? (Please share related literature, if you find some.)
Any other hypothesis someone would want to share?


texts: How can I preserve hair or saliva for future genome sequencing?

texts:
Suppose I want to preserve myself so that I can be reproduced as best as possible, in future or be simulated in future. At the moment full human genome sequencing is a bit expensive.

One could get some of my hair or saliva, but what can I do with it to best preserve it?

Would it need to be put in a freezer?

How long would the DNA of the hair or saliva be preserved for in a regular kitchen freezer?

How long would the DNA be preserved if the hair or saliva was not in a freezer?

Are there any issues of contamination?

Also, once the full genome sequencing has been done, is that all the info that could be gleaned from it genetically? can the hair/saliva be thrown out, or might it be possible that future human genome sequencing could pull more info from the sample?


texts: What prevents backflow of blood from right atrium to vena cava during atrial systole

texts: Vena cava is valve less. So,  during atrial systole what prevents backflow of blood to them?


texts: What do Caucasians see in their peripheral vision, and how is their visual field?

texts:
I am an Asian who has no idea how much of their nose Caucasians (especially for those with extremely deep-set eyes, very prominent and low brow ridges, and high noses like Brian Shimansky or Rishi Idnani) can see. I also wonder if they are distracted by their nose.

Also, what are their visual fields (nasal, upward, and downward) in degrees?

These articles have made me think of this question: http://pizzawithrice.blogspot.com/2012/08/wondering-about-white-people-visual.html?m=1

https://www.quora.com/Not-to-be-racist-but-why-do-Asians-have-smaller-eyes-and-does-it-affect-their-vision (comment of 3rd answer by Dale Thomas: "I did always want to ask. Do Caucasian men see their eyebrows and forehead? Is there any impact on vision?")


texts: I found this bug in my garden in India this morning.


texts: Identify this large, beige or pine cone-colored squareish beetle and/or the pine cone it's on?

texts:
I saw this large beige beetle on a large pine cone on the ground in February in Hsinchu county Taiwan.

It was about 4 cm long and 2 cm wide and the color was similar to the pine cone it was standing on. Though it was sunny it was cool (15 C) and the beetle didn't really respond when I picked up the cone.

I remember seeing a sign about (apparently) this species in November when hiking so I've attached it as well. I think the sign warns that this is a pest but I can't read it; I assume it is in Chinese.

Unfortunately I didn't remember the poster (from November) until later.

Any idea what it is and/or what the kind of cone that it's on, and what problems it can cause?

click images for full size


texts:
I am looking for taxonomy data of individual species and their classes something like the following format:

{
  "type": "family",
  "parentType": "order",
  "parentScientificName": "hymenoptera",
  "commonName": "ant",
  "scientificName": "formicidae"
}

{
  "type": "species",
  "parentType": "genus",
  "parentScientificName": "...",
  "commonName": "black ant",
  "scientificName": "lasius niger"
}

Basically, from this, you can construct the full taxonomic tree. When looking at the pubmed taxonomy data I don't see how to reconstruct the tree. Please show me how.


texts: I would like to ask what type of cells should someone expect in a pharyngeal smear, in a person, who is infected with a viral infection. Thank you a lot!


texts: Why do adults lose hearing at high frequencies?

texts: Children and teens can hear high pitched sounds that adults can't hear anymore. Why do adults lose high-frequency hearing?


texts: When performing mutagenesis for an assay, how do you decide on the sample size of individuals to be mutated such that all genes are covered?

texts:
If I want to study, say, gustatory response of salmons to a bile acid, I need to mutagenize a sample of salmon males. However, given that there are many genes involved in this response, what is minimum no. of salmons I should mutagenize, such that ALL the genes involved have some mutations?

I have searched quite a lot for some statistical method that tells me this, but to my surprise I haven't found any.


texts:
Water can move across the (Semipermeable non polar lipid) membrane by simple diffusion (osmosis).

But polar molecules cannot pass through the non polar lipid bilayer, they require carrier proteins to facilitate their movement.

But water as well, is a polar molecule. How and why does it simply pass through the non polar lipid bilayer by simple diffusion and not by facilitated diffusion (i.e., through carrier proteins)?


texts: When do plasmids replicate relative to its host cell cycle?

texts:
For plasmids is so much shorter than their host cell's genome (about 1/1000 in my case), it will take only 1/1000 time for it to replicate.

With respect to cell cycle, when will that replication occur?

Description of the situation I'm facing:

I have a low copy number plasmids (pSC101) in E.coli, and I'm measuring a fluorescence protein expression level. The problem is, even if the plasmid copy number is known (N), depending on when it is replicated, the number of plasmid in my cell can vary. Therefore, I cannot directly infer expression level per plasmid. Higher expression level might just result from higher number of plasmids.

For instance, if it is replicated right after cell division, I will have 2N plasmids for the most of my cell cycle.

If on the other hand, it gets replicated right before cell division (and partitioning machinery delivers exactly half the number to each daughter cell), I will have N plasmids per cell for the most my my cell cycle.

So, when do plasmids get replicated?

I could not find a similar question here with search.
Thank you very much in advance.


texts:
when isotype of the Primary antibody is IgG2a (from Mouse) and IgG2b (from Rat), how to choose secondary Antibody against these Primary isotypes?
Does secondary Antibody is that much specific to detect IgG2a/2b? What is the logic behind choosing secondary antibodies? A detailed note in this regard will highly be appreciated.


texts: Does Human being have potential to perform parthenogenesis?

texts:
Wikipedia says:

Parthenogenesis can occur without meiosis through mitotic oogenesis. This is called apomictic parthenogenesis. Mature egg cells are produced by mitotic divisions, and these cells directly develop into embryos.
In 1936, Gregory Goodwin Pincus reported successfully inducing parthenogenesis in a rabbit. In April 2004, scientists at Tokyo University of Agriculture used parthenogenesis successfully to create a fatherless mouse.

Since human is mammal,does not the success of the experimentations hints at the possibility of parthenogenesis in humans,naturally?
If not,why is  parthenogenesis not possible in human beings?


texts: Can I just simply exchange the eyepiece in a microscope?

texts: I hope it's the right place to ask about microscopy. So my question is what parameters do I have to take into account when buying a new eyepiece for my microscope? Currently I own an Aomekie XSP-42 with a WF16X eyepiece and I would like to upgrade it with a WF25X eyepiece. However when I was searching for one I couldn't help but notice that only the magnification and the mounting size are indicated. What about other parameters (eg. focal distance)? Are they standardized or they just simply don't matter?


texts:
This picture was taken from Purves' Neuroscience, chapter 5:

Image (C) shows a inhibitory postsynaptic potential whose reversal potential "goes"  to the action potential. If two or more IPSPs occur, will temporal summation cause an action potential?


texts: Absence of cytoplasmic Intermediate Filaments in Arthropods

texts: Cytoplasmic intermediate filaments such as vimentins support the architecture of the cell and have been known to aid signaling processes. However, as in this article, it is stated that out of all eumetazoans in Kingdom Animalia, only arthropods do not contain such structures. How is this possible? Are there any replacements to the conventional intermediate filaments present in cells? Do arthropods have special cellular behaviors or signaling networks to correspond with this absence?


texts: What are the effects of caffeine on the mammalian circulatory system?

texts:
A friend of mine told me an anecdote about his mother, who drank too much caffeine, to the point she became hypotensive and would pass out. Because caffeine acts as a stimulant, I'm assuming the decreased blood pressure was some kind of tolerance effect.

How exactly would caffeine have disrupted her circulatory regulation and caused her normal pressure to decrease?


texts: What happens when seeds are refrigerated before planting?

texts:
My son is doing a science research project at school, and he's chosen to research what happens when seeds are refrigerated before planting.

I cannot provide any information in regards to background research (I couldn't find any), but I want to know if refrigerating seeds before planting them will have any effect at all on the seed (so that my son's experiment can be interesting).

Thanks.


texts: How do nerve impulses travel so quickly?

texts:
Nerve impulses must travel incredibly fast to achieve the functions they do. However, I have been taught that sodium ions move down the axons by diffusion (thus causing depolarisation of the next part of the membrane etc, and this is the action potential).

However, I was under the impression that diffusion is a very slow process? How can this be the case?


texts: Why do Oak Processionary caterpillars form processions?

texts:
Firstly ,I don't live in Europe. I live in South India, and my garden has a Night Flowering Jasmine tree.
And these trees are quite popular, but notorious for their caterpillars. In our region ,there are no specific names or identification these caterpillars and the thick mat they form on the tree trunks.

And one day, I was looking through images of caterpillars online ,when one seemed similar. It was called Oak Processionary.I am not sure if the caterpillars found in my area are the same species or something else entirely, but their behavior is similar .  As per as Wikipedia and some other websites, they are usually found head to tail moving together.
My question is

Do they have some chemical signaling agent like pheromones ,or like ants when they follow each other?
Why do they form such processions in the first place? Wouldn't having such a large ,conspicuous gathering make it easier for predators to spot them from afar?


texts: How quickly can the human heart rate rise and fall?

texts:
How quickly can the human heart rate rise and lower?

For example lets say a human heart rate is rested and is at 60BPM and that person is suddenly scared to trigger their fight or flight reaction. Lets say their heart rate rises to double (120BPM).

From the above example their rate has gone from 1000ms between beats to 500ms between beats. Can the human heart instantly in one heart beat go from the 1000ms to 500ms between beats or does it need to ramp up? If yes how quickly can the heart rate ramp up?

I understand that each human heart is different, and that the speed increase and decrease will be different from person to person. What I'm looking for is a value that I can safely say the human heart won't exceed.

Similarly the same question goes to your heart going lower.


texts: What is the science behind the inaccurate perception of colors?

texts: If I go into a green room (all walls are semitransparent and green) and spend some time - around 10+ min - in there, when I come out all my eyes see is white as pink. I see no (or very few other) colors due to this for a while - around 2 minutes. What is the science behind this? Why do eyes lose color perception in this case?


texts: Detailed mechanism of the cause of diabetes mellitus type 1?

texts: I have read in some texts that diabetes mellitus type 1 is caused by degeneration of beta cells due to our body's own immune reaction.Is it true? Can you explain further how are such types of immune reactions are induced? And are there any other causative factors known?


texts: How to calculate grams of fat used during hibernation?

texts:
In Humphries et al. 2002. Nature, the authors report number of grams of fat bats use during hibernation. However, their equations results in values in mlO2/g.

How can one convert the energy requirements to amount of burnt fat resources?

I found an equation $f = \frac{20.1 \times E}{3930}$, whre $f$ is fat in grams and $E$ is energy in mlO2/g (Hayman et al. 2016. Sci. Adv.). But the paper is without any explanation as to what the numbers mean, and why they are used. Does anyone know, how to convert oxygen consumption to volume of burnt fat?


texts: Why do we still have genetic disorders that show anticipation?

texts:
Anticipation whereby symptoms of genetic disorders occur earlier and with more severity as it is passed from one generation to the next.

So wouldn't these inherited diseases over a few hundred generations affect offspring before they can reproduce and thus shouldn't these diseases like Huntington's disease no longer be with us today?

Or are most of these genetic diseases generated through sporadic mutations at a high enough rate to persist?


texts: Why was the cackling goose split off as a distinct species from the Canada goose in 2004?

texts:
According to Wikipedia, in 2004 the American Ornithologists' Union made the cackling goose a new species, splitting it away from the Canada goose.  The British followed suit in 2005.

What was the basis for this split?  Why was a new species required here?  Were offspring of these two found to be consistently infertile, or was the change based on something else?


texts:
Most tissue is comprised of cells.  Why? It would seem inefficient to have so many individual nucleus, membranes, etc.?

Specifically: Not all tissue is cellular.  Much tissue is extracellular matrix.  Since the body can use noncellular tissue, what is the role of cells in cellular tissue?

Another way to ask my question: Do the cellular organelles directly contribute to the tissue and organ's function? Or are they just there to maintain the cell itself?

My hypothesis is:

In some cases, the cellular organelles directly provide the tissue's function.  Eg endocrine system - synthesized at the cellular level.
In other cases, individual cells function discretely in the tissue.  Eg, nervous or muscular tissue.
In other cases, the cell doesn't directly support the tissue's function.  But it's needed to grow and preserve the tissue.  Eg connective tissue.
And finally, in cases where preserving and growing the tissue is a small enough task, a small number of cells simply extracellular tissue.  Eg bone tissue.

The above is my hypothesis.  Is it correct? Fix, revise, or replace it with something better!


texts:
Can anyone please tell me where is exactly the stomach in this image?

This is a sagittal section from the University of Michigan Visible Human Browsers.

Thank you.


texts: Why does blood come from mouth when people are shot in the chest area?

texts:
In almost every movie scene when a character is shot in the chest area, some blood comes from his mouth or sometimes even coughs blood before he dies.

Are these kind of scenes realistic/possible? If yes, why does blood come from mouth in this situation?


texts: Which extant species has the largest horns?

texts:
Among the bovids (cattle, antelope and all member of the Bovidae family): which species has the largest and longest horns? Please answer when including and excluding domesticated livestock and cattle.

I know that the Addax has about 85-110 cm long horns and they seem pretty long, but not as robust as a bull's horns.
Wikipedia writes that Greater Kudu has 120 cm long horns with a record of 187 cm (this figure, however, has a "citation needed" warning).
The extinct bovid Pelorovis had 1 meter horn cores and covered with keratin their length is estimated at 200 cm.
I saw in photos several (live) specimen of specially breaded cattle that had exceptionally big horns but I could not measure them.

For comparison, the longest Triceratops (an horned dinosaur) horns I know of are "Yoshi's Trike" 115 cm long horn cores with estimated total length of 130-150 cm when covered in keratin. However, the horns of Triceratops were thicker and more robust than any extant bovid's horns.


texts: How long does it take for Vitamin D3 to have physiological effect

texts:
As far as I understand Vitamin D3 has no direct physiological effect but has to be first converted. If a person if given a mega-dosis. (50000-200000 IU) of Vitamin D3, how long does it take till the body produces a physiological response?
Is it a matter of hour? Is it a matter of days?


texts: Difference between PCR for linear template and a plasmid?

texts: I believe PCR can be conducted both on a linear template and a plasmid, and I was wondering how these procedures differ in what enzymes are used, how the enzymes work on the template, primers used etc.


texts: In the same way the knee-jerk reflex is a thing (I think the nerve signal doesn't go through the brain?), can stimuli received by the eyes or ears trigger "instantaneous" (faster than the brain can process it) responses?


texts: What is a good introductory book on plant genetics for an outsider?

texts:
I am interested in plant breeding, but my knowledge about plant genetics itself is unfortunately limited (math major). Would you know of any good introductory '101' books that explain the basic concepts? As elementary as: what exactly is DNA recombination? What is an F1, F2 plant?

Many thanks and kind regards,

David


texts: Is there any evidence telling us what the oxidation state of early earth's atmosphere was?

texts:
I ask this question in relation to the origin of life. I realise it would probably be better suited to a geology stack exchange, but it does not yet exist.

The Miller-Urey experiment gives a lab based demonstration of how organic compounds may have been produced. It recreates that conditions that are thought to have existed in the early atmosphere (Hadean period).

What this experiment relies on however is an assumption that the atmosphere lacked oxygen (reducing). The Miller-Urey experiment does not produce proteins if it is conducted in a oxidizing environment. I've seen that there is some debate over the oxidation state of the atmosphere, and the main evidence for a reducing atmosphere is that life wouldn't have been able to begin without it. Is there evidence supporting an oxidized early atmosphere, and if so, how did life come about?


texts: Effect of a doubling of the start codon in a gene

texts:
I am learning about frameshift mutations. Frameshifts can occur due to a nucleotide deletion. Suppose that due to a frameshift, because of a deletion somewhere upstream from the original start codon, two additional start codons are generated, just before the stop codon in the new reading frame. What would happen in terms of translation?

AUG-GCC-AUA-AUG--------UAA
Start       Start then stop


texts: What is the reason behind that children can cry but can't laugh?

texts: I have a cousin who is almost 1 months old. As a normal child of her age, she cries a lot. But I noticed first that she doesn't laugh. So I noticed and found out that other children of her age also don't laugh. So how is it possible that childs can cry but can't laugh? What is the explanation for this?


texts: What is the state of actin-myosin in my biceps after I have flexed my arm?

texts:
When I'm starting to flex my arm, the myosin and actin slide over each other in a ratchet like mechanism. When I've totally flexed my arm, are the actinomyosin left in this contracted state? Since there is a visible decrease in length of the muscle, muscle fibres should have contracted.

So do they remain in this contracted state? Does the myosin head attach to the actin all this time? If it leave the actin, does the myosin snap back to its original position and relieve the tension/comeback to original length? Does it require any energy expenditure? Because I can keep my arm flexed throughout the day without getting fatigued. Also, What is the state of the actinomyosin if left in a half flexed state?

By state, I mean, the stage of the cross-bridge cycle


texts: Exponential growth equation and bacteria

texts:
I'm a microbiologist, but I'm teaching some ecology in my intro-level course, so when we got to population growth, I thought I'd use the example of a microbial population. But, I hit a strange problem that I thought maybe an ecologist could help me understand:

Imagine a population of bacteria that can divide every 30 minutes. In one hour, every cell produces four cells. Since no one really dies, the intrinsic growth rate (r) is 4. The exponential growth equation, dN/dt = rN works fine to show the growth of the population: starting with one cell, in one hour it's 4, then in two hours rN = 4*4 = 16, in three hours rN = 16*4 = 64 and so on. At 16 hours, we get to about 4 billion bacteria, which is exactly what the microbiologist expects.

But, we then tell the students that to make it easy to predict future numbers, we can do some math and get N(t) = N(0) e^rt. If N(0) = 1, t = 16 hours and r = 4 bacteria/hour/cell, this gives e^64 which is about 6x10^27. Yikes! Kinda far from 4 billion.

So...why doesn't this work? I feel like either I'm not understanding r correctly (it would have to be down around 0.6 for this to work out, I think) or maybe there's a limit on the equation and it just doesn't work for the absurdly high r of bacteria?

Thanks for the help...


texts: How can I compare rates of evolution for two sets of proteins?

texts:
I have a list of candidate proteins as the result of my analysis. I am now trying to find various characteristics that they have in common. One of the things I would like to check is if my candidates are evolving faster or slower than the rest of the proteins in my dataset.

Now, I know how to do this manually by building multi species alignments for each of my proteins and calculating ka/ks ratios for each set of alignments. This, however, is not a trivial process and I really do not want to do this manually for my ~1500 candidates.

Can anyone suggest a tool that will take two lists of proteins and return an estimate of evolutionary rate for each one?

I am primarily interested in human but also mouse, yeast, fly and worm. Ideally, I would need a tool that can take a list of proteins, assign them to an orthologous group and return a value representing the rate of evolution for that group.


texts: What are the implications/predictions of the selfish gene theory?

texts: Are there any testable predictions or implications of the selfish gene theory? Or it is just interesting interpretation of the observations/experimental data? If this theory is not falsifiable and doesn't generate any predictions, how can it be helpful anyway?


texts:
I am in a remote village and a young boy (second pic holding tail) says this thing is his friend. This creature is safe, we held it for pictures and released it after. None of us know what this is and we do not know who to contact. The young boy plays with it every day so it is safe but it still is strange.

These are salt water shores, not fresh water.

Someone mentioned a dugong but it is far too skinny I think. I didn't get pictures of the head as we didn't know if it had sharp teeth.
Image is taken in a remote village in Kavieng, Papua New Guinea.

The creature's head looked like this.

Link:
 polartrec.com/files/members/cara-pekarcik/images/dsc_0160.jpg

I'm no expert, but I don't believe seals are in Papua New Guinea, it's almost a hybrid of few things.


texts:
I've just learned about B cells in immunology lectures and some things are not clear to me.

Here's what I know:

1) Apparently, each B cell produces a specific antibody, determined randomly at the birth of that cell.

2) A B-cell expresses 250000 different antibodies on its surface

My question:

Are both these facts true? If so, how can they both be true if each B cell only produces a single specific antibody?


texts:
"Is there a cannabinoid autoreceptor? And if so what is the cannabinoid autoreceptor?"

(i.e. is the cannabinoid autoreceptor CB1, CB2 or is it one of the G protein coupled receptors, GPR18, GPR55 or GPR119?)

Where:

An autoreceptor is a receptor located presynaptically that sends back negative feedback that inhibits the synthesis of the neurotransmitter to which the autoreceptor belongs and this negative feedback also inhibits the release of the neurotransmitter from storage vesicles into the synaptic cleft.
The CB1 and CB2 receptors are respectively called the first and second cannabinoid receptors and are a pair of G protein coupled receptors.
GPR18, GPR55 and GPR119 are G protein coupled receptors that are also activated by some lipid messengers including a few of the endocannabinoids and their related compounds.


texts: Is there a distinction between the fisherian runaway theory and Fisher's sexy son theory?

texts:
In many websites/books they are referred to as part of the same process whereby:

"runaway" describing that the process continues even after traits become maladaptive
the "sexy son theory" explains the mechanism that underlies this.

However many sites (like wikipedia) describe them as two alternative processes.

What am I missing?


texts:
Could silicon oil block Na+ ion channels in the membrane of an axon and prevent Na+ influx?

I have been wondering if Na+ influx could have been a diluting factor in anterograde fills.  If so, could coating the axon with silicon oil prevent this?


texts: Viral RNA enrichment vs. filtering the reads out

texts: I see a lot of advertisement for viral enrichment kits, e.g. Twist Biosciences hybrid preps, which should allow to "fish" for viral DNA in vitro. Now there is another method exploited by a paper that is based on metagenomic sequencing and filtering for viral reads in silico. When I clearly see the advantage of second method in not having to buy an enrichment kit, what could speak for enrichment in vitro with a kit?


texts: What does it mean to perform in vitro experiments with mutant bacteria?

texts:
I came across the following sentence while reading the paper:

Nanchen, Annik, et al. "Cyclic AMP-dependent catabolite repression is the dominant control mechanism of metabolic fluxes under glucose limitation in Escherichia coli." Journal of bacteriology 190.7 (2008): 2323-2330.

  These in vivo flux data are qualitatively corroborated by in vitro
  enzyme activities in the Crp and Cya mutants, which exhibited
  significantly reduced activity of the key glyoxylate shunt key enzyme isocitrate lyase ...

My understanding of in vitro experiments is: those performed in artificial set up , possibly only with part of the cell, where the complete cell is not potentially alive. For, example we can test the inhibition activity of a particular enzyme by a metabolite.

In the paper cited, experiments from which flux are derived (chemostat) are considered in vivo. What would it mean to say the enzyme activity was tested in vitro on the mutant? When we say the response of the a single gene knock out mutant, the cell should be intact except for lacing one gene, which would mean that the response is in vivo.

Please help me if I am misunderstanding some thing.


texts: Minimum number of cycles for effective qPCR quantification?

texts:
I have been having an apparent problem with gDNA contamination in my no-reverse transcriptase (NRT) controls by the appearance of fluorescence peaks in my qPCR data.

I have/am trying multiple DNase treatments (Turbo DNase, Life Technologies) and RNA-clean up (Qiagen, RNeasy). The limiting factor I am worried about is that I am going to destroy all my available mRNA with multiple treatments/clean-ups.

My question is - can I lower the number of cycles I use to measure fluorescence? Is there an aspect that will go awry (in terms of the experiment itself to data analysis) if, let's say, I lower the number of cycles to 25-30? All of my contaminations start to appear within the range of roughly 30 cycles and above (as determined by the Ct values).

Please let me know if you need any other information that could help for an answer!

Best


texts: How valid are Koestler’s criticism of evolutionary theory?

texts:
I recently read Arthur Koestler's 1967 book The Ghost in the Machine. In it, Koestler criticises the neo-Darwinian theory of evolution—beneficial random mutations preserved by natural seleciton—as insufficient to explain the formation of complex forms like eyes and eggs. The issues Koestler has with the theory are ones that I've been trying to wrap my head around since before I read the book, but I'm aware that:

a) the book is half a century old;

b) Koestler was not a biologist or scientist; and

c) neo-Darwinian theory/the modern synthesis seems to have stood the test of time

so I'm wondering how accurate Koestler's account of the theory is, and if he is wrong what the retorts to his claims are. Here are two examples he gives of complex forms:

  [The giant panda] has on its forelimbs an added sixth finger, which comes in very ‘handy’ for manipulating the bamboo-shoots which are its principal food [but] that added finger would be a useless appendage without the proper muscles and nerves [and t]he chances that among all possible mutations those which produced the additional bones, muscles and nerves should have occurred independently are of course infinitesimally small.

and

  The decisive novelty of the reptiles was that, unlike amphibians, they laid their eggs on dry land...[b]ut the unborn reptile inside the egg still needed an aquatic environment...[i]t also needed a lot of food...[s]o the reptilian egg had to be provided with a large mass of yolk for food, and also with albumen—the white of egg—to provide the water. Neither the yolk by itself, nor the egg-white itself, would have had any selective value...[e]ach change, taken in isolation, would be harmful, and work against survival.

Instead of random mutations and external selection, he suggests that ‘internal selection’ works at all levels, from chemical upwards, to correct ‘misprints’ long before the developed organism is exposed to any sort of external selection. The implication that there must therefore be some plan towards which embryonic development works is supported by two examples:

  the growing eye-bud of the embryo is an autonomous holon, which, if part of its tissue is taken away, will nevertheless develop into a normal eye

and

  [the fruit fly has a recessive gene that when paired with another in a fertilised egg will produce an eyeless fly.] If now a pure stock of eyeless flies is made to inbreed, then the whole stock will have only the ‘eyeless’ mutant gene, because no normal gene can enter the stock to bring light into their darkness...within a few generations, flies appear in the inbred ‘eyeless’ stock with eyes that are perfectly normal.

His other main point is that evolution takes a zig-zag path, evolving down until reaching an evolutionary dead-ends before retracting to ‘an earlier or more primitive, but also more plastic and less committed stage—followed by a sudden advance in a new direction’. For example:

  [A]mphibian...ancestry...goes back to the most primitive type of lung-breathing fish; whereas the apparently more successful later lines of highly specialised gill-breathing fishes all came to a dead end.

and

  ...the human adult resembles more the embryo of an ape than an adult ape

Is Koestler's science just faulty, or are these valid criticisms that've been resolved since?


texts: Why do plants produce so many hybrids as a kingdom?

texts: Why do plants produce so many hybrids? I have read that they are the largest kingdom of organisms to do so. Does this have something to do with polyploidy events?


texts: Does amylolysis occur in vegetables if stored below 0⁰ Celsius?

texts:
Assume that we have a plant, e.g. kale, which is prone to amylolysis if not harvested during a frost period.

If it is harvested and put in a household freezer, such that it is frozen solid slowly enough for cell walls to burst, will the amylolysis stop, or will it still occur? Will it occur if it is kept in a fridge in the 0-4 Celsius range? If it does not occur while the vegetable is frozen, will it start after thawing?


texts: Is probability for double crossing over included in distance cM? [task]

texts:
We got this task:

There are 3 genes (acb) on one chromosome (linked inheritance). Distance a-c = 12cM, a-b=16cM. Probability for double crossing-over (CO) is 0,6%. Find ratio of genotypes of descendants (AcB/acb X acb/acb).

I don't know whether the 0,6% for double CO is included in the 16% (16cM) probability.

I think it is not, so I got these ratios:
No CO and double CO: 42% AcB/acb, 42% acb/acb,
1x CO: 8% Acb/acb, 8% acB/acb


texts:
I have trouble identifying a tree that I saw on a vacation. This is the image:

I would like to know the name of the tree, I only know that its not European.


texts: What factors, other than its homochirality, make our "brand" of biology unique?

texts: If humans were to discover organisms on another planet, it is supposed that (unless both we and they were seeded by the same source) we would have nothing to fear from alien pathogens, as they would likely be totally incompatible with our "brand" of life here on Earth. This is due to a set of fundamental particulars not inherent in all possible biologies (as apposed to physics, where characteristics are more omni-present). I know, for example, that the left-handed chirality of amino acids marks one such trait. There appears to be no reason why life could not arise with the opposite orientation. My question is, what other particulars make up this set?


texts: Neanderthal minibrains vs human minibrains

texts:
Minibrains are lab-grown balls of neurons that have some (distant) semblance to a brain.
One study showed that cells with the genome replaced with Neanderthal genes produced mini-brains that were "smaller and bumpier" than the Sapien mini-brains, suggesting a difference between the two species.
The trouble is, Sapiens and Neanderthals are extremly similar species (much closer than humans and chimps). Interbreeding made most humans today 2% Neanderthal. It seems very unlikely the difference in neural cyto-architecture would be so fundamental that it shows up in such a simple system as a minibrain. And if it was, it seems unlikely that the hybrid's brains  would even be functional.
Another hypothesis is that the neanderthal genome or epi-genome was damaged by thousands of years of exposure. I would expect a fresh Chimp genome to produce similar mini-brains to a human because the species are very close and similar cognitively up to toddler age.
Is genetic damage rather than species-difference the more likely explanation for these minibrain differences?


texts: Are cells electrically neutral or charged to setup the membrane potential across them?

texts: While studying about membrane potential I usually come across the Na K pump . But I can't understand does it cause any generation of net charge in the cell If yes then how do charged cells stay together with other similarly charged ones ,  if not why and how not .


texts: What type of Gorgonzola cheese fungus/bacteria is this?

texts: I have purchased a gorgonzola cheese and it came with some orange/yellow fungus/bacteria in the cheese's surface. Anyone know what kind of fungus/bacteria it is, and if it's safe to eat?


texts:
To create a small history of visual representations in biology, I am seeking the earliest published papers or books that have used plasmid maps as figures ; or strategies to effectively search for these publications.

I have examples like this one (from the 1977 publication presenting pBR322), but as it seems quite modern looking, it may be that earlier examples exist.


texts: Does the reverse transcriptase enzyme recognize thymine to synthesize the complementary strand of cDNA?


texts:
I was reading about whales and wondered why did only narwhals, among all other species of whales, evolve to have tusks? Is there a specific environmental reason, for example something unique about the Arctic environment that requires them to have a tusk for easier survival?
I researched a bit and found many reasons why narwhals have tusks (e.g. weapons for fighting other male narwhals to compete for mates, sensing the environment, attracting female narwhals, echolocation, stunning prey for easier hunting) but couldn’t find a reason why other whales do not have tusks.
Sources:
https://www.google.com/amp/s/api.nationalgeographic.com/distribution/public/amp/news/2017/05/drone-footage-narwhal-tusk-mystery
https://www.google.com/amp/s/ocean.si.edu/ocean-life/marine-mammals/why-tusk-real-life-unicorns-sea-and-tusks-make-them-famous%3famp=
https://oceanconservancy.org/blog/2019/03/08/exactly-narwhal-tusk/
https://scholarblogs.emory.edu/evolutionshorts/2014/04/25/the-evolutionary-significance-of-the-narwhals-tusk/


texts: Which scallops change their sex from male to female?

texts:
Tonight it occurred to me to look up what scallops are like when they are alive (beyond their culinary role) and it blew my mind. This post regards one detail about which I was unable to find specific information: apparently certain species are known to start off as male and then change to female later in their lives. Which species in particular are known to do this?

I am new to this SE community so please let me know if there's anything I should refine about this (my first) post.


texts: Can somebody identify this damselfly? Found near a stream about 15 miles west of Boston.


texts: Is [O2] different in a 5 mL liquid media?

texts: Is there a drastic difference between top and bottom of the tube, with no stirring?


texts: Abdominal muscles during inspiration/inhalation

texts:
During inspiration I am aware that the diaphragm and the external intercostal muscles contract, thus increasing the volume of the thoracic cavity.

However, I read on my textbook that during inspiration:

  the diaphragm contracts, and at the same time the external intercostal
  muscles and one set of abdominal muscles help to raise the rib cage.

What I do not understand is the movement of the abdominal muscles, as I thought that they help in ventilation during exhalation (contract during exhalation, but not during inhalation). Is my assumption incorrect?


texts: Do all multiple sequence alignments employ global alignment algorithms?

texts: Multiple sequence alignments are usually done between sequences of similar length, which resembles best a global alignment. However, I'm not sure at all what the algorithmic background would be in such case. Is it essentially a global or a local alignment when one performs a multiple sequence alignment?


texts: Microalbuminuria in inflammation of urinary tract

texts:
Albumin is excreted into urine (albuminuria) in nephrotic syndrome and in certain inflammatory conditions of urinary tract.$^1$

How is inflammation in urinary tract related to increase in albumin excretion? I know that microalbuminuria will result when albumin filtered is greater than its absorption( which takes place in nephron, not related to urinary tract).

My attempt : After some research I found this, which states cause of microalbuminuria in children may be causing infection in glomerulus, leading to increased permeability of glomerular basement membrane.

So, will it be correct to say that UT inflammation is not causing directly microalbuminuria?


texts: Difference between biological control and introducing species for conservation?

texts:
I have a biology assignment and we have to explain various methods and strategies for conservation, two of which are:

  Biological control
  Introduced Species

What is the difference between these? I was under the impression that they are essentially the same thing – biological control being the introduction of species to predate pests (eg. the abysmal failure of the cane toad).

Any clarification would be great.


texts:
What are the oldest fossils of modern man? What is the evidence until now? I do not ask to know the evolutionary
chain that led to H. sapiens, but I wouldn't mind to hear it, nevertheless.

What are the official sources, like peer reviewed journals, confirming it?

I wish for reference and rigorous scientific analysis.


texts: I understand fish from salmon farms are inferior, so I am wondering if it would be better to 'seed' the original waterways with wild caught roe/milt?  I am sure it is complicated, but so is salmon farming!


texts: Typical cellular respiration lab with a respirometer -- why is potassium hydroxide (KOH) necessary?

texts:
For context, if you are unsure what this question is in reference to, feel free to take a look at this video by Bozeman science and go forward to about the 2:00 mark. In a typical cellular respiration lab, in particular the one outlined by the College Board, a respirometer and some peas are used to measure the rate of respiration. What confuses me is why KOH (potassium hydroxide) is necessary so that the interior volume of the respirometer won't change. Why wouldn't the solid formed by 2KOH combining with CO2 (K2CO3) cause a change in volume, since it occupies space in the respirometer just like the gasses? Sorry if this seems like a silly question, I have very poor background knowledge of chemistry.

For an animation, feel free to view this link from Pearson.

Thanks!


texts:
I've had friends see the boat and giant teeth of a giant shark attack of a boat in Japan. (Teeth larger than a great white). [I can't find anything about this on the Internet].
In addition, this report from Pakistan seems to suggest that there are large sharks in the deep of the Oceans.

15-TON PREHISTORIC SHARK CAPTURED OFF COAST OF PAKISTAN

Karachi | A giant prehistoric shark previously thought to be extinct for more than 20 million years has been captured by local fishermen off the coast of Pakistan, reports the Islamabad Herald this morning.
The giant creature first thought to be a great white shark was rapidly declared by experts to be an unknown species of shark as it’s great weight and size were unheard of. Analysis of the teeth suggest the shark to be a parent of the Megalodon, an extinct species of shark that lived approximately 28 to 1.5 million years ago, during the Cenozoic Era.
The sea creature that measures an incredible 10.4 meters and weighs an astounding 15.6 tons is the largest living shark ever caught to date, great white sharks reaching an impressive 7 tons at full growth, a size that is no match for this giant prehistoric shark that can reach an imposing 20 meters in length and possibly weight up to 30 tons, depending on estimates.

My question is: Is there evidence to suggest that sharks from prehistoric times live in the deep of the oceans?


texts: Visual and clear example of the idea that "animal doesn't need to understand the evolutionary function of its actions"

texts:
This is a question about education. I am trying to come up with a very visual and clear example, to explain a particular concept in evolution.

The concept I am trying to explain is,

  the fact that an animal does not need to understand why it's doing something in order for that behaviour to be selected

(by "why" I mean, the evolutionary/functional role of that behaviour, the reason why it increases the animal's fitness).

Students who don't yet intuitively understand evolution, sometimes mistakenly think that in the theory of evolution, animals need to understand why their behaviour is leading to offspring in order to do that behaviour. (they might say: "the bee looks for flowers because it wants to feed his children", although bees (probably) don't actually make this computation, but simply act on stimuli).

(Note by the way that this is not simply about anthropomorphization: e.g. humans also don't need to understand what sex is for, in order to produce offspring).

What I'm looking for is an example of an animal, and a behaviour that is characteristic for that animal, that very clearly shows this principle:

It should be clear and intuitive, that the animal doesn't understand "why" it's doing what it's doing, because to reason about this would clearly be too complicated for the animal (I don't think the bee example really satisfies this).
It should be visual, and memorable.


texts:
I would like to attract cyanobacteria in one spot on an object (e.g. cloth,) instead of having it swim in the media. my current method is to pour it on the object in a beaker and wait for some of them to become attached (very pour attachment yield).
Now, I am thinking of making the object emit light. Do you think that the bacteria will swim all the way to the cloth because there are attracted to light?
is there a better method to help the bacteria get attached to the cloth?


texts: How to retrieve logical expression (KO based) for reactions from KEGG?

texts:
Whether a module is complete or not can easily be checked by evaluating the Definition entry associated with the module; e.g. in module M00010, it is given by

Definition  K01647 (K01681,K01682) (K00031,K00030)

which can be translated to

K01647 AND (K01681 OR K01682) AND (K00031 OR K00030)

If this expression evaluates to TRUE, the module is complete.

Now I am wondering whether analogue information exists for a single reaction. So e.g. for R00352, one finds the following information about Orthology:

But how do I now know in which logical relation the KOs are?

So it could be

K01648 AND K15230 AND K15231

or

K01648 OR (K15230 AND K15231)

and so on.

Can this information be retrieved from KEGG and if so, how?

EDIT:

In the above example, the correct expression would be:

K01648 OR (K15230 AND K15231)

One either needs K01648 or the other two subunits together. So, unfortunately, it is not as easy as @aretaon describes it in his answer since just one of the two subunits would not be sufficient. One can therefore not just connect the KOs associated to a reaction using a logical OR.


texts: What is the most up-to-date CRISPR/Cas9 protocol?

texts:
I am collecting literature to start a new project on CRISPR/Cas9 gene editing. I must put together a protocol to start and am intending to use the following paper as guidance:

"Genome engineering using the CRISPR-Cas9 system". Nature Protocol 8(11):2281-308 · November 2013

Could you please indicate whether this is the most reliable and recent published general protocol for the CRISPR/Cas9 system.


texts: Has anyone used Crispr/Cas to induce a knock-in in MEF cells?

texts: Does anyone have experience with the CRISPR/CAS9 platform performed on MEF? Or does anyone recall any relevant articles?


texts: I've been told in my zoology class that the blastopore is an imaginary pore found in gastrula, from which mouth develops first in protostomes and anus develops first in deuterostomes. But we've also been told about the famous blastopore grafting in newts experiment by Spemann-Mangold. So how can you graft something which is imaginary? Is the blastopore really an imaginary pore?


texts: How to keep activated sludge viable for a week?

texts: I am working in biological waste water treatment and I need to collect some activated sludge samples and have them characterized through different methods. The characterization will take from a few days to a week. How do I keep the sludge viable in this time? How do I make sure the bacteria do not die?


texts: What kind of grasshopper-like insect is this?

texts: We found this thing in our basement. Not quite an average grasshopper. Any ideas?


texts:
My textbook says that in both groups of seedless plants (vascular plants, non-vascular plants) the gametophyte is a free-living plant, independent of the sporophyte.
I don't understand this statement and am now wondering if the sporophyte and gametophyte  are stages in a plant's lifecycle, or are they individual parts of the plant, or are the sporophyte and the gametophyte different plants altogether? Secondly, does this differ depending on the organism?

Different plants or different structures that make up the same organism?


texts: Can concentration of a protein be determined from a gel quantitatively (rough estimation)?

texts: I've got a His-tagged protein in 6M urea, 500 mM imidazole buffer that needs to be quantified before dialysis to ensure there's enough protein worth dialysing. I ran out of my elution buffer which should be used for blanking. I made a fresh buffer with the same contents, it started giving me false results. I could interpret that problem is with the buffer (probably because of change in chemical batch) from the readings I got in BCA and Bradford assays. Hence, I ran a gel to get an idea of presence of protein. Are there ways to estimate protein concentration quantitatively from the gel?


texts:
Why is it good to use Glycerol as carbon source to produce intermediates in pharmaceuticals?

My best guess would be because it produces a lot of ATP per carbon. But I haven't found anything to verify my hunch.


texts:
Acquired lactose intolerance may occur due to a sudden and high intake of milk-based diets. Lactase is an inducible enzyme.

So if lactase is an inducible enzyme then why increase intake of lactose is causing negative effect? Why more lactase isn't produced in more lactose intake conditions?


texts: What kind of event would cause the current Mitochondrial Eve to be replaced by a new one?

texts:
Apparently all living humans are matrilineal descendants of a single woman who lived 200.000 years ago. She is called Mitochondrial Eve.

But at the time she lived there was a different matrilineal ancestor that all living humans shared. And between then and now I imagine many other women have been Mitochondrial Eves of the human population that lived at a particular time.

What I'm wondering is what kinds of events would cause a different, more recent matrilineal ancestor to become the Mitochondrial Eve of all living humans?

One scenario I can image is that the human population is on the brink of extinction and literally only a few people survive. Because there are so few people alive, I imagine that the chance that they share a more recent matrilineal ancestor is high.

Are there other scenarios possible? Does the chance of a new Mitochondrial Eve emerging decrease if the human population is large (billions) instead of small (hundreds or thousands)? Suppose that the human population will not decrease, is it likely future human populations will ever have a different Mitochondrial Eve than the current population? Does it depend on the amount of people that migrate?

The same questions could be posed for Y-Chromosomal Adam and the most recent common ancestor of all humans, I guess...


texts:
This baby snake just came inside my house in Sri Lanka, and I'm wondering whether it is venomous. Do you know this snake?

I am posting this from my phone so I am unable to format properly. And I have small children in my house, therefore I am worried about their safety.

Size: < 30 cm (I think it was a baby snake).

Location: Sri Lanka (in southern Asia)

We live in an urban area without any rivers near by.


texts: What errors can occur during DNA replication?

texts:
When there is an error in copying DNA (a mutation), what exactly goes wrong?

If G goes with C and A goes with T, I don't see how that part can mess up.

Is the idea that when the double helix is split, an A gets ruined and replaced with a G by mistake, which then pairs with a C in one of the copies? So something that was supposed to be AT is now GC.


texts: How does prolonged exposure to high frequency noise affect hearing?

texts:
Is there any research showing how prolonged exposure to background noises, particularly high frequency noises, affect hearing abilities? Does constant high pitched noise cause damage even a low volumes? E.g an alarm sounding, noise of an air plane, or noise from road works and building sites.

If so, what is the effect? and why does it happen?


texts: Realistic Application of CRISPR in Human Disorders

texts: Human trials recently began to use the genome editing technology CRISPR to treat sickle cell anemia using edited stem cells. Sickle cell anemia is caused by a single DNA Mutation, and is also a disorder of the red blood cell.  Given that this is a more simplistic genetic issue to address (i.e. there is only one DNA mutation to correct), and that the disorder affects an easily replaceable connective tissue, is the application of CRISPR limited as a treatment? Could CRISPR be used to treat disorders that are a results of multiple DNA mutation, and that affect a different types of tissue?


texts: Does an increased reproduction/mortality rate provide an evolutionary advantage?

texts:
If a species has a high mortality/birth rate, then it is able to adapt to changing environments more quickly than species that live for a long time.

Without a high mortality rate, food and other natural resources are hogged by previous generations and the gene pool is polluted when less evolved, older animals reproduce.

Because of this, wouldn't it make sense to conclude that a high mortality/birth rate is better for a species as a whole?
This advantage could snowball out of control, because faster evolution would lead to superior reproduction methods which would lead to faster evolution etc...

If this is true, then why are mice not more successful and adapted to their environment?

House mice were chosen because of their high birth and mortality rates.
Birth rate:
"Approximately 6 mice can multiply into more than 60 mice in 3 months."
http://www.crittercatchersinc.com/critters/Mice/Mousereproduction.html
Lifespan: 1 year
http://themysteriousworld.com/top-10-shortest-living-animals-in-the-world/
One of the reasons these traits may be more harmful than helpful is that predators benefit from a population increase. I managed to find this article in my research:
http://www.ncbi.nlm.nih.gov/pubmed/12675374
Feel free to include this source in your answer if I have interpreted it correctly. The reason I am posting this question answerless is because I am not sure enough about the conclusions I have drawn to answer it on my own and (mostly this) because I am very interested to see what other disadvantages this evolutionary strategy would have.


texts: I very rarely sneeze just once, usually there's two coming in a row, and I've noticed the same thing in other people and even in animals.  Is there any reason for this?


texts:
So today while clearing the trash out of my room I found this orange spider on an abandoned piece of foam.

 It is carrying a weird ball with it wherever it goes. What is this? And to which genus does this spider belongs?

For a better contrast I placed it on  paper.

EDIT-1

Size: Roughly 1cm in length

Location: Uttar Pradesh, India. Coordinates- https://maps.app.goo.gl/svXoxaH4Z2lK2rFH2

Temperature: 34°C and Humid.

EDIT-2

Adding few more pics


texts: My textbook states that the higher concentration of solutes, the greater the osmotic pressure will be and the greater the pull of water in will be. However, osmotic pressure is defined "as the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis." Therefore wouldn't a high osmotic pressure PREVENT water from passing, not pull water in? Can someone please clarify this for me so it makes sense? Thank you!


texts: Is there any scientific evidence that a human has ever grown a third set of teeth?

texts:
This is about the possibility (or lack thereof) for a person to re-grow a new "permanent tooth" or set of teeth, to replace the teeth that grew after their milk teeth fell out.

I had earlier seen some anecdotal evidence on the internet that this would have happened to some people.

Anyway, what I wanted to ask is if there is any scientific evidence (e.g. properly recorded unusual medical phenomena) that shows that a person has grown a tooth (or a set of teeth) to replace their permanent teeth?


texts: Artificial Propagation and it's relation to asexual reproduction

texts:
I know that asexual reproduction is also called vegetative reproduction. However I do not understand it's relation to artificial propagation. Is it a technique used for asexual reproduction (the method by which plants reproduce asexually) or is artificial propagation another name for asexual reproduction.

Am I right when I say artificial propagation techniques provide the means for plants to reproduce asexually?

Also, is my understanding of asexual reproduction and artificial propagation correct:

In asexual reproduction, a parent plant produces offspring that are genetically identical to it and to each other. Asexual reproduction produces clones as the offspring and the parent are clones of one another. Asexual reproduction can be an advantage when environmental conditions are stable and an organism is well-adapted to its environment. The genetically identical off spring will also be adapted to that environment. Asexual reproduction is carried out by the different artificial propagation techniques. Artificial propagation is the cloning of a plant from a portion of its roots, stems, or leaves. In asexual reproduction in plants, also called vegetative propagation, new individuals are grown from a portion of the roots, stems, or leaves of the existing plant. Artificial propagation involves using plants’ natural ability to reproduce vegetative. This process enables farmers and gardeners to select the parent plants for specific traits.


texts: Long term effects of "brain freeze" on the cerebral vasculature

texts:
According to one theory, ice cream headaches are caused by an increase in blood volume of the anterior cerebral artery:

Another theory into the cause of ice-cream headaches is explained by increased blood flow to the brain through the anterior cerebral artery, which supplies oxygenated blood to most medial portions of the frontal lobes and superior medial parietal lobes. This increase in blood volume and resulting increase in size in this artery is thought to bring on the pain associated with an ice-cream headache.
(from Wikipedia)

Does repeatedly experiencing this phenomenon put someone at higher risk for some sort of cerebral vascular accident, or is it not any more harmful than a small increase in blood pressure that one might experience under exertion, despite the painful nature of the headache?


texts: Is it possible to stimulate the EPOC process?

texts:
On Wikipedia, EPOC is defined as:

  Excess post-exercise oxygen consumption (EPOC, informally called afterburn) is a measurably increased rate of oxygen intake following strenuous activity intended to erase the body's "oxygen deficit".

My question is what influence has post exercise habits on the efficiency of this process?
For example, after an intense exercise, a person rests in bed during this process, consuming a very low amount of oxygen.
Would this process be stimulated if this person would ride the bike for 30 minutes, very slow, but enough to put the cardio-respiratory system at work?


texts: Population Genetics Using WGS: How do I know when I have enough individuals?

texts: I am having a difficult time finding information about a minimum threshold for number of individuals to use in wgs pop gen analyses. Are there software or formulas/theory available to determine what number total number of haplotypes/individuals you need to get theta estimates, make a linkage map, run mk tests etc based on inputs such as genome size, read depth per individual, sequencing platform? Obviously there can be financial constraints and considerations to make for non-model organisms when choosing how many individuals to sequence. Any advice would be appreciated. Thanks!


texts:
I think most of the people on this site know about the famous Baltimore paper describing the ability of the poliovirus to replicate itself without the need of cells but I want to expand on the issue and ask could it be possible to have truly "cell-free" Life-e.g. life forms that do not have cells in any form according to modern biology but yet can be considered "alive" by its standards? This is the first paper in historical context describing the possibility of creating a self-replicating molecule in the laboratory. Well, it's about a viral genome and it only can self-replicate so it's not like it's alive according to what we consider "true" living organism, but nevertheless it triggers an interesting chain of assumptions in my mind. What if we could design a system where nucleic acid can evolve outside of cells? Then, what if we managed to provide an energy source t drive this evolution outside of the context of cells? Would such nucleic acid evolving on its own in a test tube depending only on the energy source we provide and on the specific conditions in the test tube be considered equal to a gene evolving in a "true" living organism? What if then we managed to add more nucleic acid's molecules to the system, just enough to have all the components involved in the replication of the evolving nucleic acid molecules synthesized by the system itself? Then can we consider this system analogous to a living organism, e.g. truly alive? What if we continued adding nucleic acid molecules to the system to the point when it was able to produce ATP from organic molecules used by what we commonly consider to be "alive", e.g. entities we prescribe the name living organisms, like glucose, for example. Then what would be the difference between this chemical reaction system and a genuine living organism? What if we continued building up this "in vitro metabolism" to the point when we have a genuine "molecule laboratory" testing the fitness of new nucleic acid molecules to itself. A true evolving, replicating and self-organizing molecular "machinery" we could "grow" in a test tube. Would we then consider such a thing a genuine living organism and if so why?

Yes, I know it's a "fringe question" and out of the scope of almost all branches of biology but nevertheless I think it's one of those questions that can "capture our mind". So, do you think there could possibly be such a thing that we could deem "alive" but have no cells at all? Something organized in such a way that we can readily call it a life form but yet not organized in the "way we think" about Life in general? If this is possible, when do you think this system of reactions could be called genuine living organism?

To the moderators-my question is different than the question "Why isn't a virus alive?" because it has a much broader perspective than it-a cell free form of Life can be anything-from a self-replicating "grey goo" to an evolving tornado. Viruses are only one small particular subset of possible answers. Plus the question you are referring to isn't about synthetic biology and the possible diversity of life forms as is mine but is only about a particular aspect of what we call a virus-its pertaining to the set of life forms or not. My question has both different direction and different set of objects it's aimed at. How can the two be identical, then?


texts: Digestion Enzymes in Carbohydrate Metabolism?

texts: Digestion of carbohydrates is ending in small intestine with mainly disaccharidases. Isomaltose is broken down to 2 molecules of glucose by the enzyme called alpha dextrinase(oligo-1,6 glucosidase or isomaltase) which hydrloyze 1,6 linkage of isomaltose. In the case of glycogen metabolism there is debranching enzymes that are transferase and alpha 1,6 glucosidase. According to this informations can we say that alpha dextrinase (isomaltase) and alpha 1,6glucosidase are the same enzyme ?


texts: Is there a program that simulates biology on a molecular level?

texts: Is there a computer program that simulates biology on a molecular level? Software that has rules that simulates the rules of molecular-biology?


texts: Is it possible for human beings to feed through the nose?

texts:
There is a prediction on a futurology site that food can be eaten by inhalation

https://2050.earth/predictions/smell-can-feed-you

Although aerosol foods do exist they are still eaten by the mouth.

Is there any biological evidence that human beings can feed through their noses?


texts: Appropriate Buffer for electerophoresis of DNA & Protein TBE or TAE?

texts:
Which buffer is best for DNA Electrophoresis and which is best for Protein to be have a sharp bond?

Considering a higher electrical conductivity compared to TAE & TBE and the generation of less heat. If anyone has a particular formulation (add other materials to improve quality) which is obtained as a result of practical experience. I would be grateful if you send me that.


texts:
Ethics in Paleontology

Fossils help researchers understand the evolution of many lineages of plants and animals. But, who actually owns fossils? What if an important fossil (say a transitional fossil like Tiktaalik or Basilosaurus) were found by an amateur fossil hunter and sold to a private collector? Should there be regulation of fossil hunting to prevent loss of scientific information? Should all "important" fossils be turned over to museums?


texts:
I'm curious to learn about the 'most human' teratoma ever recorded. By that I mean a teratoma which most resembles the form of a human being.

I suppose there are several factors which would contribute to this criteria:
-Most organs, and components found in a human (e.g. brain, teeth, organs, etc.)
-Most closely organized structurally like a developing human.

Also I was wondering. Given the right conditions could a teratoma grow into a living being? Could they theoretically develop the necessary organs to be excised from their host and sustain the functions necessary for survival.

Basically I am curious to learn about the possibility of teratoma maturing into a bonafide organism.


texts: Looking for a good and complete Enzimology exercises book

texts:
I mean, I want to practice with challenging exercises and I want to know the theory behind them. So, I started reading:

Organic Chemistry: Yurkanis, P.
Enzyme kinetics: Bisswanger, H.
Biotechnology procedures and experiments Handbook: Harisha, S.
But just the first one has problems and not about enzymes at all.

So, I looking for a good (theoretic) and complete (challenging with exercises) book about enzymes.


texts:
I'm going to teach a c ollege-level introductory entomology course soon, and I'm looking for free online entomology resources. Does anyone have any recommendations?

In particular I'm looking for phylogenetic resources, experiment ideas, images, topics, etc.

Ideally, I'd love to find a discussion forum consisting of other entomology instructors sharing their ideas.

Thank you!


texts: Why should I degas my gel solution for polyacrylamide gels?

texts:
In protocols for polyacrylamide gel electrophoresis (PAGE) I often see instructions to degas the gel solution by putting it under vacuum for 10-15 minutes before polymerizing the gel.

I usually don't do this, and when I tried it once I couldn't see any difference. So I'm wondering what exactly the degassing is meant to achieve and how big the effect should be.

What effect is degassing the gel solution supposed to have?
How important is degassing to achieve good gels?

Any literature that examines the effect of degassing would be appreciated.


texts: Resource for model organism anatomy/physiology for biological experiments

texts:
I'm looking for a resource that best surveys the anatomy and physiology of common genetic model organisms, and how their characteristics are particularly useful for biological experiments.

For example, I'm studying the eyeless Drosophila gene, but it would help to know that species' specific compound eye anatomy and normal development, so that I can weigh the pros and cons of using that particular model organism over another.


texts:
A well-known and commonly-done experiment is to extract DNA from strawberries or other fruit by first mashing the fruit of choice, adding the mush to a mixture of water, salt, and detergent, and then adding isopropanol. DNA then precipitates out.
How intact is the DNA obtained from this experiment? Does the experiment introduce breaks or other forms of DNA damage? Is the DNA intact enough to be sequenced and for one to be able to identify what organism it came from?


texts: What digitally encoded smell formats exist?

texts:
Is there a defacto format for storing and transmitting smell digitally? Where can I obtain samples of such smell encodings? What reference dataset exists against which I can compare my smell sample to determine it might be the scent of an 'orange' or other scent?

There seems to be a lot of mostly theoretical material about how smell can be analysed, but little if any actual digital samples or reference data for conducting concrete experiments on that data.


texts: Does the existence of one species imply the existence of many other?

texts:
Reading one of Sir Arthur Clarke's scifi stories, I came across a statement something to the effect of, existence of a single species automatically implies the existence of many other species. So considering multi-cellular organisms, something more complex than a virus/bacteria, if we know for a fact that there is one species (plant/animal whatever) then without directly observing any other species or any obvious evidence, can we deduce that there must be other species? Assume we are in a completely new environment like a brand new planet discovered with life on it. Does the existence of a  species imply existence of many other species?

Thanks.


texts: Regarding an activator, does the C amp cap complex, bind to the coding strand, the template strand, or both?


texts: Lotka-Voltera predator prey model isocline?

texts:
In lotka voltera predator prey model, why do we get a straight isocline with variable prey/predator population for single value of corresponding predator/prey?

I understand that we get the prey isocline by the equation

N1=prey population ; n2=predator population

What I don't understand is why we are getting variable prey population on isocline for same value of predator population. Shouldn't the prey population be also constant?

PS: I picked the graph image from the internet so the symbols are different. Sorry.


texts: Inter-codon mutations statistical analysis

texts:
I am looking for a statistical approach to inter-codon mutations. For example a 64*64 (64*63 actually) table, that contain the possibility of mutation from one codon to another codon (CCA to CAA or CGG... for example).

Is there any articles, databases or others that provide such table?

Please comment if my question is not completely clear.
I searched but didn't find an answer for this question in Google Scholar.


texts: For every 104 male babies, we have 100 female babies and there are statistics which are more reliable. (Those tell us that we have 997 female infants born per 1000 male infants born.) What is the reason for that? Why do we have more male babies than female babies?


texts: How long can algae survive with no air recycling (closed bottle)

texts:
In a small bottle nearly filled of Chlorella in water and grow medium, how long would it take for them to die (with or without light).

Thanks in advance ;)


texts: Obtaining protein atomic co-ordinates from dihedral angles

texts:
https://en.wikipedia.org/wiki/Dihedral_angle#/media/File:Protein_backbone_PhiPsiOmega_drawing.svg

I've been reading on Protein Amino Acid Sequences and their 3D structure. It seems that the 3D structure is encoded by the three torsion angles as shown above. My professor said there is a 1-1 encoding between 3d cartesian coordinates and the torsion angles, but I cannot find any way to do this either in pyrosetta or biopython. Is there any formulas/packages that would be of use for this conversion?


texts: What are the factors that contribute to genetically identical individuals behaving differently?

texts:
If you run the same task on a pair of identical computers, you will end up getting the same results, even with the same response time.

But let's say you line two different person, and ask them the exact same question. Each will answer totally different, even if they are twins, raised in the same family, went to the same school and shared the same roof, and probably had the same experience in life. One of them may love carrots, one may not.

The question is, what is generating such different behaviour and way of thinking? Aren't they sharing the same genes?

If yes, the question is still standing.

If no, then we'll have another question:

If we create 2 identical clones of a person, raise them in the same situation, will they think identical too? If not, why? And what's the reason of this?


texts: Compatibility between spytag/spycatcher versions

texts:
Background
SpyTag and SpyCatcher are peptides which can associate via a spontaneous amide bond. Because of this, they can be fused to proteins of interest as tags to cause the proteins to bind. There are (currently) three versions of the spytag-spycatcher system, where each system contains a different version of spytag and catcher (i.e. system 1 contains spytag1 and spycatcher1, system2 contains spytag2 and spycatcher2, and system3 contains spytag3 and spycatcher3).
Question
My question is, how compatible are the spytag and spycatchers between different versions? So, for example, would spytag1 bind with spycatcher2?
Prior Research
I found the following statement from this paper:

The new variants showed backwards compatibility, reacting efficiently with parental versions (SpyTag002 with SpyCatcher: 1.0±0.06×104  m−1 s−1; SpyTag with SpyCatcher002: 5.5±0.03×103  m −1 s−1;..

But these numbers don't mean a lot to me. Would you expect to see near complete binding as with spytag2-spycatcher2?


texts: What happens to IP3 molecules after release from IP3 receptors?

texts: IP3 molecules bind to IP3 receptors and open up the calcium channels on the endoplasmic reticulum. I am wondering what happens to IP3 molecules after they have been released from the IP3 receptor? Do they remain as IP3 molecules, or do they break down? Do they have any purpose after they have been released, and perhaps after been broken down?


texts: How to interpret McDonald-Kreitman test results?

texts: It is easy to get the numbers right and calculate neutrality index. It is easy to memorize "equals", "greater", "lesser", etc. At least on the exams, when certain level of simplicity is assumed. But instead of memorizing I'd prefer to understand. So far I struggle to get past the numbers. Could anyone, please, explain reasoning behind the them? Why certain values means the trait is advantageous or not? An easy to understand example would be helpful as well. Thank you.


texts: Is consuming sugar with food as beneficial as consuming glucose (~half of the amount of sugar)?

texts: A few years back I heard at biology class that sugar's molecule consists of half the number of elements of a glucose molecule. So not counting the energy needed to transform two sugar molecules in one glucose molecule, isn't it almost the same (eating N amount of sugar) as eating N/2 of glucose?


texts: How would oncogenes be targeted for therapy and are there any examples of existing therapies for such cancers if the gene was upregulated (i) as a result of copy number variation and (ii) due to increased promoter activity?


texts: Why is a hippo so big if it has round about the same genes as a mouse

texts: My science teacher told us that all mammals have round about the same number of genes. This confuses me, since there are very big and very small mammals. Where do genes come from and why do animals have such large differences in size between one another even if they have around the same amount of genes?


texts: Since the Y-chromosome can only pass from male to male child, it would seem to pass intact. Thus, a boy's Y-chromosomes would, I guess, be the same as his father's. Going backwards, would not all men have identical Y-chromosomes for this reason, being somewhat like mitochondrial DNA?


texts:
This may be better suited for the English language SE, but When discussing evolutionary changes in species is it proper to refer to their phenotypes?

In this context:

  "Imagine if a cow did not have to cart around however many gallons of
  culture nor expend personal time and effort into chewing its cud. It
  could lose all that anatomy and energy expenditure from its phenotype."

it could just be me, but it sounds strange using it in that context.


texts:
In reading the annotated Origin... I have come to the following note by Costa on p. 168:

  Again, modern biologists would disagree with Darwin's idea that especially well-developed traits vary to a greater degree than expected simply because they have been varying and undergoing selection in the past (as evidence by their considerable development)...

I am not sure I understand what the problem with Darwin's view is. From reading his work I understood that he, Darwin, is simply saying that traits that have been more recently acted on by natural selection would vary more than those that have been acted in the past and over a longer period of time (given that conditions remain relatively the same - I assume).

What is the modern view of biologists on this?

P.S. The excerpt to which this side note refers, follows:

  In these remarks we have referred to special parts or organs being still variable, because they have recently varied and thus come to differ; but we have also seen in the second Chapter that the same principle applies to the whole individual; for in a district where many species of any genus are found - that is, where there has been much former variation and differentiation, or where the manufactory of new specific forms has been actively at work - there, on an average, we now find most varieties or incipient species.


texts: I'm reading about medicine and specifically opioids. There seems to be a wide variety of forms of these chemicals, I'm curious as to what purpose these serve in these respective plants, and why they function the way they do in mammals.


texts:
Size growth after birth seems to be the norm in the animal kingdom (as well as among plants). This makes sense. It's evidently physically challenging for an animal to produce an offspring of its equal size, both if born through gestation or eggs.

But, is this always the case? Are there exceptions, i.e. animals that are born at their "normal", adult size? I don't seem to find any (nor that I am a biologist or expert on the topic).


texts: What is it that specifically kills ALS patients?

texts:
ALS is a fatal motor neuron disease, and even though there are many different articles out there on the topic "How does ALS actually kill you?", none of them really delve deep enough into biology to adequately answer the question.

For instance, many articles cite "respiratory failure", or "CO2 poisoning". But the last time I checked, ALS doesn't make your lungs explode or cause your body to start producing toxic levels of CO2. So obviously, we need another level of detail here to support these claims. I'd be willing to be that with "respiratory failure", either the neurons innervating the diaphragm break down (hence you become physically unable to draw air in and push CO2 out), or perhaps the tiny/micronic structures inside your alveoli become impaired for some reason. If the former, then why wouldn't a ventilator/respirator help the patient?

Either way, I'm interested in a biological/neurological explanation for why ALS is considered to be (ultimately) fatal.


texts: Are facial 'cleansing' products 'effective' on human skin, and if so, what is their mechanism of action?

texts:
All major supermarkets and beauty stores stock some form of facial cleansing products. They come in the form of scrubs, gels, and lotions which vary in application (from in shower, to apply daily without rinsing). Many of these are not marketed towards clearing acne or other legitimate dermatological problems. The claims these products make tend to include: reduction of dry/oily skin, neutralizing skin PH levels, and clearing pores. I am unsure if any of these terms are reflective of a real problem, or if the products can even even help said issues.

Therefore, this is a three-part question:

Do facial cleansing products actually do what they claim?
If so, what is their mechanism of action (i.e., how do the ingredients work)?
If not, what do the ingredients in the product actually do to human skin?

Examples of such products and associated claims:

Deep Clean® Invigorating Foaming Scrub by Neutrogena
Dr. Alkaitis Organic Purifying Facial Cleanser
L'Occitane Aqua Reotier Gel Cleanser

Example ingredients from the Neutrogena product above:

  Water, Glycerin, Sodium Laureth Sulfate, Cellulose, Lauryl Glucoside, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Microcrystalline Cellulose, Phenoxyethanol, Fragrance, Synthetic Wax, Methylparaben, Sodium Hydroxide, Menthol, Disodium EDTA, Polyquaternium-7, Sodium Benzotriazolyl Butylphenol Sulfonate, Ultramarines, Blue 1


texts: ID of this flower/plant and origin if possible

texts:
Hello again all you helpers out there!

So this plant or flower is found in Virginia (USA) rural area mainly woodland and grassplains, when it comes up, it rarely last for very long, so with a photo of the plant in its glory, i hope some of you could tell me, what kind of plant/flower it is and where it came from, thank you very much and have a great weekend!

/Beo


texts: What do arranging and assigning mean in sequence annotation?

texts:
Please could someone explain these lines to me in a simple way

  These sequences were then arranged based on some overlapping regions present in them. This required generation of overlapping fragments for sequencing. These sequences were subsequently annotated and assigned to each chromosome

What do "arranging" and "assigning" mean in this context?

Source: NCERT class 12 (This text in in reference to the method developed by Frederick Sanger)


texts: Do we know if dogs are asymptomatic transmiters of sars-cov-2?

texts: Dogs do not use mask when going for a walk nor they observe the security distance. On the contrary, they frequently join their noses, and put their noses where other dogs had put them before or had urinated. So, as they are our pets, it is important to know if they can be asymptomatic transmiters of sars-cov-2. Do we know it? At least, have we tested asymtomatic pets of people infected with sars-cov-2?


texts: Are there any commercially available fluorescent dyes that will bind only to double stranded DNA (not RNA, single stranded DNA etc.) for studying in vitro using confocal microscopy?