texts:
I would say that one of features that separates human consciousness from animal is the ability override instinctive behavior. A human infant will jerk its hand away from a hot surface. An older child you can communicate with at the basic level may not although experimenting with this is no doubt unethical. An adult can consciously overcome this instinct.

Are there experiments testing this idea with animals? In animals that science claims are self-aware, it would be interesting to know if they can overcome the automatic reaction to negative instincts.
The first step would possibly be to see if one negative instinct can be overcome in the presence of another. Like will a really hungry chimp walk across a painfully hot surface to reach food? This seems likely but I am unaware of any such testing.

A more interesting example will would be cases of real animal altruism. Science is quick to tout what some call animal altruism as hardcoded and evolving genetically e.g. lions defending prides, mothers defending young. And I agree this can be hardcoded and genetic since I am not aware of lions NOT defending prides or mothers leaving young to predators.

However, these links show cases of what some may call true animal altruism. Dogs braving the danger of the highway to help other animals.
https://www.quora.com/Are-animals-capable-of-selflessness-Do-they-have-the-desire-to-help-others

Leopardess adopts baby baboon
https://www.youtube.com/watch?v=j9DOxH5RyWQ


texts: Does the number of base pairs between the end of one gene and the start of the next gene have to be a multiple of 3?

texts:
I'm working on a project for a Coursera course where I need to scan a string of base pairs and identify possible genes, but there's something about real DNA that I need to know to design the algorithm correctly.  My question is best illustrated by example.

Suppose we have a strand of DNA like this : ATGxxxyyyzzzTAAqqATGrsssATGuuTAAvpppTAG

The lower case letters just stand for general base pairs that are not in the sequences "ATG", "TAA", "TAG", or "TGA".

"ATGxxxyyyzzzTAA" constitutes a gene for the purposes of the assignment, and my program does correctly identify that string of base pairs as a gene. What I want to know focuses on what happens after that first gene is found. Let's consider the last portion of the string:

"qqATGrsssATGuuTAAvpppTAG"

My current gene-finding program would identify "ATGrsssATGuuTAA" as a gene, but notice that this strand starts after only two base-pairs ("qq") have been searched through. Does that matter? I.e., would this happen in real DNA, or should the second valid gene be identified as "ATGuuTAAvpppTAG"?


texts: Found this bug in my bed. Don't think it's a bed bug. Pretty small but fat and round and had deep reddish coloring.


texts: What actually happens when my leg 'falls asleep'?

texts: Most people have experienced the temporary loss of feeling and tingling in their leg resulting from sitting in an abnormal position for a short while. Usually you get a loss of feeling in your leg while it is being compressed/constricted at some point and then the tingling sensation as the pressure is removed. But what is actually happening? I understand the the blood vessels are probably constricted from the pressure, but how does this lead to loss of feeling and later the strange tingling sensation? Are there any other things that extended compression on the leg does to cause this? What exactly are the requirements to get the sensation of a one's leg or other limb falling tingling in that manner?


texts: Is there any evidence of animals wanting to die? Specifically, animal communication which says "come and eat me".


texts: The role of antibodies interacting with cancer

texts:
I'm learning about antibodies. As I understand it, antibodies detect stranger cells/bacterial/viruses by the molecules present in their membranes. In cancer cells, the cancer cell have produce some unknown protein, so why antibody cannot detect that molecule and kill them?

Is it that the cancer cell is surrounded by a normal cell?

Or is the protein it produces is not obvious in the cell membrane?

Or that the protein can bypass antibody? if so, why?


texts: Why did women historically have such a high mortality rate during birth?

texts:
Historically women had a relatively high chance of dying while giving birth.

At first thought it seems to me that this would be a disadvantage for the species for the obvious reason that a dead person can no longer give birth (and can't care for her offspring).

Is this outweighed by some advantages? I can imagine that there would be some evolutionary advantage to have the "weaker" women die during child birth and let the "stronger" ones live to produce more children with "stronger" genes.

Or is the high mortality rate in humans during child birth a result of civilization (pre-moderne civilization of course, with the general lack of hygiene/medical knowledge)?

What is it like for the relatively un-civilized tribes around the world?

How is it compared to other closely related mammals?


texts:
The DNA Testing firm in the below article claims that its tests were "99.99 per cent" accurate.

http://www.telegraph.co.uk/news/uknews/1322077/False-DNA-test-led-father-to-reject-daughter.html

Googling "dna test accuracy" has led to numerous websites many of which claim an accuracy of their DNA testing to be 99.9%, with some even 100%!

How does a firm calculate this percentage accuracy? It seems to me that experimental data would not be useful in determining this percentage accuracy as there is no way to really confirm the fact that Bob is the son of John and vice versa as that is what we're trying to find out. Do they do so by factoring in slight inaccuracies in the laboratory procedure?

Acquiring experimental data would not be useful as I described above for paternity testing, a useful application of DNA testing, but could, to my knowledge, be used to determine the percentage accuracy of DNA testing in the recognition sense. By DNA testing various cells of the same person, and then seeing how many of them result to be from the same individual according to the DNA test (understanding that scientifically every cell should have the same DNA but then experimentally acquiring results that show that 999 in every 1000 cells show to link back to the same person) seems to be a working method...Is this how it works? Is this the notion conveyed with the idea of the percentage accuracy of DNA testing?


texts: What are the effects of non-ultraviolet light radiation on DNA?

texts: I am trying better understand the effects of varying the frequency of light on DNA, however, most of what comes up is "UV light" and how it is damaging to DNA (presumably by ionization). Have there been any studies on radiation on DNA at lower frequencies of light?


texts: How can one draw a crossover between ABK and aBk where genes A and B follow the Mendel's law of independent assortment and gene K does not i.e. K is linked to B?


texts: Is there a hard and fast rule of which one is stronger than the other, or does it depend on their context in a protein?


texts: Don't understand figures in this citizen-science mosquito ID project

texts:
The Citizen-based mosquito monitoring system is a Citizen-Science vector tracking project that involves using any of a wide variety of cell phones to capture "sound bites" (sorry!) of mosquitos. These are collected and analyzed in order to gain some insight into the distribution of different species of mosquitos at different times and locations. Attention is paid to ensure the system works with older model phones that are distributed more widely.
While a positive identification of a single insect form a single recording is not likely this way, over time a statistical analysis is expected to give meaningful information. I believe the idea is that similar sounding species are expected to not be in similar places at similar times so often that it muddles the identification too much. This is citizen-science; imperfection is not a deal-breaker.
I was happy to see that there is a BioRvix paper. In fact, I was surprised to see there is such at thing as BioRvix in the first place!
The principle is illustrated in Figure 5, and some of the argument behind species differentiation is illustrated in Figure 7, and screenshots of both are shown below.
I think there is a lot of information densely packed within the figures, and I'd like to understand more of it. In the second figure below, which is Figure 7 in the paper, what does the color scale and color coding represent?
There seems to be some suggestion of time of day as well, but I don't understand exactly how. What about time of year - that should also play a major role.

Some may recognize Manu Prakash as "Foldscope guy".


texts: How Plausible is Restoration of Cryonically Preserved People?

texts:
I fear death (so much that I'll prefer a year/few of torture over death), and plan to sign up for cryonics. I would like to know how plausible it is, why the answer would be so, and if possible how many years away would revival be.

Thanks.

I have read a lot of articles on Alcor, and done several hours of research since yesterday. Mainstream Science seems to assign infinitesimal probabilities against, it, but the guys at Alcor (and other Cryonic institutes like Cryonics.org think they've got a case). It seems theoretically possible to me, but I don't want to but into too much hype—so how plausible is it?


texts: Can plant roots absorb dissolved oxygen from water, or do they require actual bubbles in the water?

texts:
Plant roots generally require some exposure to air.  Deep water culture is a form of hydroponics where plants' roots are left to soak in water.  To keep the roots from "suffocating", most online sources recommend some kind of aeration mechanism, such as an air stone.

These systems normally wind up filling the water with bubbles, right under the plants.  So my question is: are the bubbles responsible for keeping the plants alive, or is the dissolved oxygen keeping the plants alive?  So for example, could plants live immediately downstream of a waterfall (a natural aerator), even out of range of its bubbles?


texts: What wavelengths of lights do plants need to grow?

texts:
So, I found a list of L.E.D.'s from Cree here (the company seems to be known for efficiency, they power most of the bicycle lights that I know of) is selling a line of lights designed for growing plants.  If you click on the data sheets, you'll find something like this:

Now, I know that plants reflect green preferentially because it is the least useful color to them (energetically speaking) so I assume that this matters.

I know the first few things about electronics, so I would really like to use one of these in something that I build.  However,the question becomes:

What kind of spectrum light and I looking for?  What is the difference between the "vertical farming" lights and the greenhouse lights?  (Viewing angle?

I kind of want to put some plants in a box coated internally with aluminum foil (it can reflect more than 90% of the energy), and hook one of these bad boys up for some inside growing.  Thanks alot.


texts: Dilute DNA plasmids with distilled water

texts:
I just extracted the DNA plasmid from E.Coli and dilute them in EB buffer. However, I've just figured out that the next step, which is electroporation, required that the DNA plasmid be diluted in Distilled H2O. Can anybody help me to know how to transfer the DNA plasmid from EB buffer to Distilled H2O?
To be clear, the EB buffer I used is from Qiagen. It contains 10mM Tris-Cl, pH 8.5.
https://www.qiagen.com/sg/resources/faq?id=d8ef773f-6a37-4993-908b-8bbc7bc5c8d6&lang=en


texts:
everyone.

Since I am new in the flow cytometry technique, I am not really sure how to analyze the result.
We use cell U-937 Lymphoblast.All Cells

Could Anyone help to explain me this one?

Thanks in advance!


texts: How did the activities of protocells become inheritable?

texts: I have learned that first a protocell came to exist and its characteristics came to be passed on by genetic material. So how come genes for all the activities come to incorporate into genetic material? Did genetic material come first and random sequences made random proteins that were used to make cells ?


texts: Why replication collapse but not stall leads to DNA break?

texts: I have been looking into the concept of replication dynamics and was wondering why collapsing but not stalling leads to a DNA break.


texts: What is the function of the Hyoepiglottic ligament?

texts:
The hyoepiglottic ligament (ligamentum hyoepiglotticum) is an elastic band that connects the epiglottis to the hyoid bone.

Although I can find information about the clinical significance of this ligament (mentioned here), I have not been able to find a definitive or reputable description of its actual physiology/function.

Can anyone provide a reputably-supported description of the function (physiology) of the hyoepiglottic ligament?

My thought was that the hyoepiglottic ligament might act as a see-saw during swallowing. Specifically, my assumption was that as the hyoid is raised during swallowing (thus raising the hyo- end of the ligament), the opposite end of the hyoepiglottic ligament (attached to the epiglottis) is pushed down, forcing the epiglottis to cover the glottis to prevent food stuffs from getting into the trachea. Is this possibly right?


texts: How do we know if a neuron is inhibitory or excitatory?

texts:
The textbook examples for an excitatory neurotransmitter is Glutamate, and for an inhibitory neurotransmitter it is GABA.

In my naive understanding, a neuron was inhibitory or excitatory depending on the neurotransmitter it releases onto its postsynaptic partners.

According to this thread, however, a neurotransmitter is not per se excitatory or inhibitory, but this property depends on the postsynaptic receptor it is acting on.

Now this property seems independent of the presynaptic cell - hence, how can we classify the presynaptic cell of being either inhibitory or excitatory (when that is a property of the postsynaptic receptors, which can be either)?

Besides, given that we a huge number of neurons and their connections in each $mm^3$, how can we be sure that the presynaptic's cells action are not mediated by other cells, and the observed inhibition/excitation is not rather a network effect?


texts: How does Haloxyfop control young grassy weeds in fields of broadleaved crops?

texts: Haloxyfop (haloxyfop-P-methyl) is a selective herbicide used to control grassy weeds in young stages. The mode of action (iirc) is basically inhibition of acetyl CoA carboxylase (ACCase). Why does this affect the monocots, while not harming the dicots?


texts: What is the effect of TSH on the calcitonin?

texts: I know that TSH is released from the pituitary gland and it motivates the thyroid gland to release thyroxine, and calcitonin is released when the calcium level is high in the blood, but is calcitonin affected by TSH or not, I didn't find a specific answer on google, could you help me please?


texts: Role of Calcium and Magnesium in capacitation/acrosome reaction

texts:
During the acrosome reaction, the activation enzyme present in the sperm dissolves the corona radiata and zona pellucida enabling the sperm to reach the plasma membrane of the egg.
Also calcium and magnesium ions play an important role in acrosome reaction [ref].
What I fail to understand is how exactly do calcium and magnesium ions play a key role in acrosome reaction?


texts: Get "DNA" of one parent based on its children

texts:
I'm no biology expert so bear with me, but I've been given a task to estimate alleles of an animal based on the animal's children and the children's other parents.
I've looked up Mendel's laws but I'm not sure I can possibly determine the correct result - better show an example:
Let us say that we want to get alleles of a mother. We know the following:
Child 1 has alleles: AG, the father of the child has alleles: AG
Child 2 has alleles: GG, the father of the child has alleles: GG
Child 3 has alleles: GG, the father of the child has alleles: GG
According to Mendel's laws and the example above it would seem that
For the first child x father pair - the mother would have alleles AG
For the second and third child x father pair - the mother would have alleles either GG or it could have AG, CG or TG.
How can I determine which anwser is correct?
If needed I can provide more examples.

EDIT: More examples / clarification

I have a database of animals (cows/bulls). Each animal has ~50 000 SNPs, each SNP has 2 alleles.
However, some of the animals data are missing, for instance I do not have SNPs for a certain bull, but I do have SNPs of the bull's children and their mothers.
Now I need to figure out an algorithm that based on the SNPs of said children and the SNPs of their mothers tries to compute the SNPs of the bull.
Additional example: (each row represents a child - mother pair)
SNP                                 | Child alleles | Mother alleles | Possible father alleles
ARS-BFGL-BAC-19454  | GG               | AG                   | AG, GG
ARS-BFGL-BAC-19454  | AA                | AG                   | AG, AA

From the table above it is clear that the bull can only have AG.
However I do not know how to handle the following case:
SNP                                 | Child alleles | Mother alleles | Possible father alleles
ARS-BFGL-BAC-14220  | AG               | AG                   | AA, AG, GG
ARS-BFGL-BAC-14220  | GG               | GG                   | GG, AG, CG, TG
From the table above it looks like the bull can have either AG or GG - how do I figure out whether the father's value is AG or GG?


texts: Are there testosterone receptors in female mammary tissue?

texts:
Does female mammary tissue have receptors for testosterone hormones?

Do male hormones influence female mammary glands, as female hormones influenced the male mammary tissue, such as in gynecomastia?


texts: Does neural oscillation happen at the same frequency in all parts of the brain simultaneously?

texts:
Does neural oscillation happen at the same rate in all parts of the brain at a given time?

I'm trying to learn and understand about brainwaves, and I know about the various categories of brainwave. Therefore, my question is are all parts of the brain firing off at the same frequency at any given time or are some parts for example operating at a delta frequency and others operating at alpha frequency? Do different types of brainwave occur simultaneously or is always all of the brain operating at one frequency?


texts: How nasal hairs filter particles of micron size?

texts:
This book says:

  The larger particles (> 10 μm diameter) are filtered by hair in the nostrils

If we see the anatomy of nasal hairs and its density in the nostrils then it seems that its impossible for such a structure to filter particles in micrometers, So how does the nasal hairs filter them?


texts: Is it possible that a person can't produce, like, dopamine, serotonin, and other emotion hormones? Or, a part of the brain can't function to make one feel something?


texts: How does a woodpecker not give itself concussions?

texts: How does a woodpecker go about smacking it's head into a tree without killing itself?


texts: How do warm-blooded animals keep their temperatures constant?

texts:
Warm blooded animals like us keep their temperature constant irrespective of their surroundings. But how do they do that? Energy should be supplied from the inside. I assume that reactions like making ATP from glucose are exothermic. That means in winter our body reacts more. Water is absorbed by those reaction.We should need more water in winter. Which is contradictory with our real life experience.

On the other hand what prevents cold blooded animals from making heat? Don't they need ATP? Do they use different types of reactions to make energy? Do they have different evolutionary path? They don't seems very different from us.


texts: Can telegony happen in humans like in Telostylinus angusticollis?

texts: Is it possible for a human male to transmit features of his phenotype via non-genetic semen-borne factors to his mate's subsequent offspring sired by another male? As it happens in flies (Crean et al., 2014).


texts: Why do three nucleotides code for one amino acid? Why not 5 nucleotides?

texts: We all know why there are 3-base codons, and why there aren't any 2-base codons. But why is there not a 4-base a 5-base codon?


texts: Do species ever move into new territory and then die out because of the local diseases?

texts: We usually hear that an invasive species has brought with it a disease which it itself shrugs off easily, but which then decimates the local population which has never encountered it before. It's a very common story. But it doesn't make sense to me. Surely it should be far more common for the reverse to happen? Surely a newly arriving species has to face not just one or two new things in the new environment, from one or two new individuals, but an entire environment coming at it from every direction with hundreds of viruses, bacteria and competitors it has never come across before. So how come the story is always that the invading species kills off the locals, when you would expect the invading species to have hundreds of totally new threats and strange foods to handle, would be unable to cope, and would die out?


texts: How are the various classes of E coli genes determined?

texts:
Looking at some more detailed codon usage tables, genes may be further clustered into three gene classes: Metabolic genes, highly expressed genes during exponential growth, and horizontal gene transfer. Looking at the original paper by Medique et al., they clustered the genes based on the CAI and then by a variant of k-means determined 3 classes. Note that this is different from a class II gene which is determined by the types of RNA polymerase used.

How did they end up determining what the three classes are? It seems as if they made this generalization without any proteome data. Would the same genes be classified using a protein expression data during exponential growth and stationary growth?


texts: Assays for protein or lipid content of insect pupae

texts:
Does anyone have any recommendations (based on personal experience) for rapid, cheap, accurate assays for estimating protein & lipid content of individual insect (mosquito) pupae?

So far I've come across chloroform/methanol extraction for lipids, and Kjedahl procedure + Nesslerization for protein (link).

Mosquito pupae are not particularly tough as insect pupae go, but ideally I'm looking for personal experience that the method can cope with the sorts of sample I need to use it for.

(I strongly suspect similar assays have been developed for Drosophila so have added that as a tag.)


texts: Is there a minimum load below which an infectious agent will not cause disease?

texts: Suppose a single smallpox virus is injected in an human adult's body. Will it cause disease in the host? Is there a minimum microbial load below which it will not cause disease?


texts:
i am interested in Lynn Margulis' book Mystery Dance: On the Evolution of Human Sexuality.

i don't find it in libraries and it's too old and i am too poor for paying 20 euros for a 1991 book.

Does anybody know a more modern book about human sexuality evolution?


texts: How can the directionality of a protein structure be defined?

texts:
For a DNA molecule, you can define directionality using the convention of a 5'-3' direction on the Sense strand. However, using an N to C convention for a protein doesn't work since the ends may be on the same side and if the protein is unstructured then the N to C direction will change. I'm asking the question from the perspective of addressing PPIs. If I have two proteins that interact with each other, how do you quantitatively describe the relationship of the two proteins with respect to one another. We have formal ways to describing this using domains and residues but not for quaternary structures.

How would you mathematically define "up" for a protein structure?

I would imagine that using RDCs would be able to make some progress into this problem. At the moment it doesn't seem as if there is any convention in the structural biophysics community.


texts: Fat people have a large amount of calories (energy) stored, but I have noticed all time when they do physical activities they get tired fast in comparison to fit people - why does this happen?


texts: What is the purpose of segments in citrus fruit? In my experience, each segment usually contains from zero to two seeds. I may have seen more but only rarely, if I remember correctly. What is the significance of having more than one seed in a section (twinning, perhaps)?


texts: How does an embryo produce waste products even when its organ systems are not developed fully ? How does the placenta identify or differentiate waste materials from embryo ? Which organelle or specific cell acts as excretory organ ?


texts: How can Chronic myeloid Leukaemic drugs reduce the production of the Philadelphia genotype?

texts:
How can Chronic Myeloid Leukaemic drugs (Tyrosine kinase inhibitors, e.g. imatinib, etc.) that act by inhibiting bind of ATP to the active site of the BCR-ABL1 protein actually reduce the prevalence of the Philadelphia chromosome? (For example, optimal response to TKIs in 3 months would be Ph+ <35% and/or BCR-ABL1 <10%.) What I am actually asking is how a drug that targets the result of the oncogene (the BCR-ABL1 protein) can have an effect on the source (ie. genotype of the cells), as CML is a clonal haematopoietic stem cell disorder?
An example Reference paper: Apperley JF. Chronic myeloid leukaemia. Lancet. 2015 Apr 11;385(9976):1447-59. doi: 10.1016/S0140-6736(13)62120-0. Epub 2014 Dec 5. PMID: 25484026.


texts: Kidney failure → Inhibition of Na+/K+ pump → Heart failure

texts:
I read in my biology book:

  Due to kidney failure, the concentration of K+ in the body increases. This can lead to heart failure too.

But there wasn't any explanation to the mechanism of this phenomenon. So, I took help of the internet, found out about the Na+/K+ pump and its role in muscle contraction on the Wikipedia page.

But, there wasn't any direct mention of the relation between inhibition of Na+/K+ ion pump and kidney failure. After some brainstorming, I hypothesized the following mechanism:

Due to kidney failure, the aldosterone-catalysed mechanism for keeping the Na+ concentration static in bloodstream stops. So, Na+ ions filtrated by the nephron can't go back to the bloodstream, resulting in a decreased concentration of Na+. Then, the decreased potential difference between intra and extracellular space, in terms of Na+ ions, inhibits the Na+/K+ pump. As muscle contraction is dependent on the Na+/K+ pump, heart muscles stop to work.

Is my hypothesis right?


texts: How do the biophysics of how cerebrospinal fluid mechanically protects the brain work?

texts:
The two mechanisms I've seen mentioned are the cerebrospinal fluid (CSF) acting as a hydraulic cushion or shock absorber, and how CSF creates a micro-gravity environment through buoyancy.
I have very little understanding of the former, but I do have a vague idea about the latter: since the brain is submerged in a fluid (the densities of the brain and CSF are also similar I think), it experiences a buoyant force upwards that counteracts the force of gravity on the brain, therefore decreasing its "effective weight" from around 1400g to about 50g. How does this help precisely? The explanation I've seen that I could understand is that it makes it so that the brain isn't pressed up against the base of the skull due to gravity, and so that it doesn't get deformed under its own weight. This buoyancy also helps the various structures attached to the brain, like nerve roots and blood vessels, hold it up and support it. Wikipedia also says that it allows the brain to maintain its density without being impaired by its own weight, which would cut off blood supply and kill neurons in the lower sections without CSF. This explanation is plausible but I'm not sure if it's the entire story.
There's also this bit from "Neuroscience in Medicine" that says the decrease in effective weight decreases injury by reducing brain momentum in response to stresses/strains inflicted on the head. How does that work? I'm not super familiar with the physics of buoyancy, I just know the basics. I don't understand how it reduces momentum during movement.
I couldn't find anything that went into the physics of the whole hydraulic cushion thing, so an explanation for that would be great.


texts: Honeybee relatedness: workers and nephews

texts:
This is my first question on this site. If anyone could help me get to the bottom of it, I would be very grateful.

I am currently working on a lecture on kinship in animals. It goes without saying, it includes a part about the good old honeybee and its unusual relatedness coefficients. One of the interesting points I'd like to cover is worker policing, where workers remove eggs of other workers because they are more closely related to their brothers (the queen's sons) than their nephews. The resources I'm using state that this situation depends on whether the queen is monogamous or polygamous. When a queen mates with a single drone, workers are more closely related to their nephews (r=0.375) than their brothers (r=0.25). However, if a queen mates with more drones, the situation is flipped, workers are more closely related to their brothers and therefore eliminate unfertilized eggs laid by other workers.

The issue I'm having may seem silly and purely technical, but I can't for the life of me figure out how we arrive at a relatedness coefficient of 0.375 for worker and nephew when the queen is monogamous. I'd really like to understand this because I want to be able to answer as many potential questions students may have, and I can't do that if I'm not 100% sure about it. Any and all help is greatly appreciated. Thanks in advance!


texts: While in motion, why do closer objects appear to move faster?

texts: When I look outside the window while travelling by a car, why do closer things seem to be moving faster and appear unclear but the farther ones seem to be moving slower and appear clear?


texts: Looking for books on How the limbic system works and it role in non-verbal behavior

texts:
This is my first post. I just read and I'm currently studying a book called "How everybody works" as a guide to understanding nonverbal behaviors.

After I'm done studying it and while I experiment with its claims; I'm looking to understand more of how the limbic system works and its role in human emotions.

The book's premise is that the limbic system makes us react to certain situations in such ways that nonverbal behavior is expressed; therefore by understanding the limbic system and nonverbal behavior we can ascertain a person's reaction to outside stimuli and gain insight.

If anyone could provide recommendations on books about the Limbic system
that are up to date with current finds or any other books that relate to the topics above I would greatly appreciate it.


texts: why is the cleavage in frogs holoblastic and not meroblastic?

texts:
background information
The cleavage of the frog embryo during the embryo development is holoblastic (complete cleavage). However when we look at yolk-rich eggs we see a cleavage pattern which is meroblastic (partial cleavage).

Question
But the frog eggs are also yolk rich right? So why do frog embryo's use holoblastic cleavage?


texts: Does recombination slow mutation accumulation in sexual populations? Is there any evidence?

texts: Mullers Ratchet is the process by which asexual organisms would accumulate mutations without bound. It is claimed that sexual organisms would slow this mutation accumulation through recombination. Is there any evidence that recombination achieves this? Preferably experimental evidence.


texts: How can the number of chromosome change during evolution

texts:
I found an explanation here, which is basically saying that sometimes the centromeres are duplicated, breaking a chromosome into two halves. But how could this propagate?  I don't think inbreeding is efficient enough for this mutation to become dominant, and it should take a lot of pregnancies for the mutants and the regular ones to produce an healthy offspring. Is the explanation in the link backed by any evidence?
Thank you!

By the way, do we know how many chromosomes did the latest common ancestor of human and chimpanzee have, and when did chimpanzee gain the extra pair of chromosomes (or when did we lose it)?


texts: Does Human Female Meiosis II occur after fertilization with sperm?

texts:
I am reading the answer and I am getting confused by the sentence:

  At the end of meiosis I females have two daughter cells and meiosis II
  only occurs if and when fertilization occurs by a sperm cell.

The clause suggests me that meiosis II starts after the sperm has ignited the fertilization process in female: I do not know how that exactly works.

Wikipedia says:

  The process of fertilization involves a sperm fusing with an ovum.

So female meiosis II must happen before the sperm fuses with the ovum.
Sperm must ignite some process in female that puts female meiosis II going on before sperm can fuse with egg. Is that right? How is that going to happen?


texts: Mutating a protein without mutating the gene?

texts:
Is it possible to mutate a region of a protein (says about 300 amino acids long) without actually mutating the gene?

One possible way that I can think of is to use RNAi and specifically block that region of the mRNA which codes for the 300 amino acids in the protein?

But then wouldn't it cause a problem in the translation of the remaining region of the protein?

Are there any methods out there to mutate a region of a protein without mutating the DNA?


texts: This is the gut area of an Eastern Grey Kangaroo taken of a property in the Southern Highlands of NSW, Australia. The top red organ appears to be the spleen but what is the elongated tubular organ extending from the spleen? Is it a deformation or the result of disease?


texts: Why can't ciliary muscles in the human eye relax like other muscles?

texts:
I had laser eye surgery a decade ago, but in recent years my eyesight has become significantly myopic. I consulted an ophthalmologist to see if this was eye strain because I work at computers a lot, or part of a natural degradation of the eye over time, or both. My ophthalmologist seems to believe that in my case I'm youngish enough that the natural degradation with age is minimal, and that it's mostly eye strain that is my problem. She believes I can get my eyesight back to roughly 90% of my post-surgery sight ability, if I can reduce eye strain. She gave me some eye drops to help with dryness, and recommended various ways to for me to help my eyes recuperate.

I decided to look into eye strain to learn more about what conditions cause it and what can alleviate it. What I learned is that the lens of the eye needs to be flatter to accommodate focusing on far objects, and rounded to focus on near objects. The way the lens becomes flat is by using spring-like connective tissue called choroids that pull it taught. Attached to these choroids are muscles called ciliary muscles that stretch the choroids out when they contract. This action causes the choroids to stop pulling on the lens, and the lens will retract into a more rounded shape. So, when the ciliary muscles are relaxed, you can see far. When the ciliary muscles are contracted, you can see close up. This diagram from the York University website was the clearest explanation I have come across:

Thus, the reason for my current inability to focus on far objects is that so much focusing on close objects, mainly computer monitors, is straining my eyes. In order to regain the ability to focus on far objects, I need to reduce strain and allow the muscles to relax. If they relax, the choroids can pull the eye to the flatter shape needed to see far.

However, I can't reconcile that model with how I understand the mechanics of the other muscles in my body. If I go to the gym and run or lift weights, or in any way expose my muscles to work, they respond by getting stronger without sacrificing the ability to stop contracting. The muscles in my body don't lose the ability to relax, no matter how much I train them. I have never heard of anyone who worked out too hard or too long such that their bicep would remain in a permanent state of contraction.

In fact, in my experience, after a hard workout, it's impossible to prevent my muscles from relaxing and resisting doing more work. When I do a bicep curl at the gym, and I do it to the point that I can't lift the weight anymore, my muscle gives up and I drop the weight. Similarly, if I've spent a long time looking at close up objects, shouldn't my ciliary muscles give up, allowing the choroids to take over, making clear far vision the unavoidable outcome?

The idea that my ciliary muscles need to relax in order to see far also seems to contradict my personal anecdotal experience. Sometimes I am able to see far away, but I can't hold it for more than a few seconds. If I try to maintain focus on far objects for too long, I get an uncomfortable feeling in my eyes that is hard to describe, but it's a form of pain that forces me to give up. My vision goes blurry, and I can only see close objects again. If my bicep worked the same way, it would be as if it hurt to let my arm hang straight down with a weight, and the only way to alleviate it would be to raise the weight, which makes no sense. I feel like the effort is in seeing far, and that when I'm tired, I can only see close up.

It's not that the case that I think that all medical research on the eye has it backwards, it must be that there is some aspect of this that I am not seeing (pun intended).

How can it be that the ciliary muscles, unlike other muscles, lose their ability to relax?

Why is it that my ciliary muscles don't become exhausted and allow the choroids to take over by default?


texts: This Sequence Data (DNA) has very few Methionin-starts. How is that possible?

texts:
I'm working on my first sequencing related project and I'm trying to find proteins with a specific PFAM ID (PF11999). The project is called "MMETSP", I searched the annotations for that ID, identified signal peptides using SignalP and their target locations with a tool called MultiLoc2 (I was looking for extracellular targets only).

Out of the very few sequences that where left after all this filtering, none of the DNA-bits started with the basepair-code "ATG", for Methionine. How can this be?

I used the shell to calculate that only 1,83% of all the sequences start with ATG.
Any ideas on this?


texts:
Today while cooking with potatoes when I cut open a potato(raw) which was looking perfect from the outside showed purple veins. I threw it in my kitchen garden but than I wondered what it could be

Questions

Why did my potato developed these purple patterns?
What could be that purple pigment?
Are such potatoes Edible?

PS: The potato was not old. It was quite fresh.


texts: How would constantly growing nails have aided early human?

texts: Nails grow rapidly and constantly, such that without constant artificial trimming they would reach lengths difficult to manage. How did this benefit early humans, say 200kya? Were they used like claws? Did physical activity keep them at a short length?


texts: Why do moths not die when they fly into a window?

texts:
Sometimes at night when I'm inside with a light on, I can hear (I'm sure) moths fly into the window, and it's so loud I can sometimes hear it over the TV from the other side of the room.

Since they're so small, how do they hit the window hard enough to cause such a big noise and not die?


texts: How do neurons inverse an action potential?

texts:
See the following figure (source):

The pathway on the right (SN $\rightarrow$ interneuron $\rightarrow$ F Neuron $ \rightarrow $ flexor muscle), is explained as follows:

  The action potential in the sensory neuron invades the synaptic terminal of the sensory neuron causing the release of transmitter, and subsequent excitation of the postsynaptic interneuron colored black.  This neuron is called an interneuron because it is interposed between one neuron (here the SN) and another neuron (here the MN).  The excitation of the interneuron leads to the initiation of an action potential and the subsequent release of transmitter from the presynaptic terminal of the interneuron (black triangle), but for this branch of the circuit, the transmitter leads to an IPSP in the postsynaptic flexor (F) motor neuron (colored red).  The functional consequences of this feedforward inhibition it is to decrease the probability of the flexor motor neuron becoming active and producing an inappropriate flexion of the leg.

Specifically, it states that but for this branch of the circuit, the transmitter leads to an IPSP in the postsynaptic flexor (F) motor neuron. But it doesn't give an explanation of how this works.

How can a neuron generate an inhibitory postsynaptic potential when it is given an action potential? Can this specific neuron inverse the signal? How does that work?


texts: Question about total protein normalisation in western blot image analysis

texts:
I am analysing western blot data and I am using total protein normalisation using Ponceau S. My supervisor and I have agreed to use total protein normalisation for my western blots instead of using housekeeping proteins such as Beta-actin and GAPDH, due to the fact that studies have shown that housekeeping proteins levels differ between experimental groups, and during different developmental phases. I’ve also read literature where single protein loading controls were compared with total protein stains and it was found that the total protein stains lead to more reproducible and accurate quantification.
When quantifying Ponceau S staining, I have seen in multiple papers that they outline the entire lane, and measure its integrated density. However, I have two western blots, so I am analysing two Ponceau-stained membrane images. In one image of my Ponceau-stained membrane, there are bubbles which obscure parts of the top and sides of some of the lanes. So I cannot outline the entire lane when doing quantification. My supervisor has advised me that I should instead outline a band on the lane corresponding to where my protein of interest is, and use that for normalisation. I have also seen in a paper they outline a small rectangular section of the lane when doing total protein normalisation instead of the whole lane.
However, I don't understand how total protein in each sample can be quantified if one is outlining only a portion of the lane. If you're outlining only a rectangular band on the lane, you are only measuring a portion of the total protein in the sample. As a result, you are not normalising against the total protein in the sample. I was wondering if anyone knows what the reasoning is behind outlining a portion of the lane when doing normalisation with total protein stains?


texts: What does "dissection-based microscopy" mean as described here, and how can it give genetic information?

texts:
The Phys.org article 'DNA microscopy' offers entirely new way to image cells references the new Open Access paper in Cell DNA Microscopy: Optics-free Spatio-genetic Imaging by a Stand-Alone Chemical Reaction.
My question is not about DNA microscopy, but instead about the second kind of microscopy mentioned in the explanation below quoted from the Phys.org article

Until now, microscopy fit into two main categories. The first is based on optics; light microscopy, for example, dates back to the 1600s and relies on visible light to illuminate samples. Scientists have riffed on this approach, even going beyond the visible spectrum. Electron microscopes, fluorescence microscopes, light-sheet microscopes ¬- they're all based on the principle that samples emit photons or electrons, and the microscope detects the emission.
The second category is based on dissecting samples at locations defined by a microscope. Computer programs then stitch together each dissected piece into a complete picture of the intact sample. Optical imaging can offer intricate portraits of subcellular structure and action. Dissection-based microscopy can give scientists genetic information.

I don't really understand exactly what is being referenced by the 2nd paragraph. What is "Dissection-based microscopy" and how can it give genetic information?
The passage seems to repeat a few sentences in the introduction to the Cell paper:

These approaches closely mirror the two ways in which microscopic images have been acquired to date: either (1) detecting electromagnetic radiation (e.g., photons or electrons) that has interacted with or been emitted by a sample, or (2) interrogating known locations by physical contact or ablation (e.g., dissection).

This may shed some light on the question for those more familliar with the techniques discussed, but I still don't understand what technique this is really referring to.
See also NY Times' DNA Microscope Sees ‘Through the Eyes of the Cell’


texts:
What differentiates chemokines from chemoattractants? They both are grouped by their chemotaxic function, but what features separate them.

What are examples of other chemoattractants that are not chemokines? Or examples that are not even proteins at all?


texts: how to reconcile PDB structures' sequences via Uniprot references?

texts:
I’m trying to reconcile structures  in PDB entries with their  sequences as reported in their chemList.polymer.dbref entries.

E.g.: considering structures for HIV integrase:

PDB:3OS0 references UNP:P14350, focusing on integrase (len=391)

>sp|P14350|752-1143
CNTKKPNLDAELDQLLQGHYIKGYPKQYTYFLEDGKVKVSRPEGVKIIPPQSDRQKIVLQ…NRTVSIDNLKPTSHQNGTTNDTATMDHLEKNE

PDB:2B4J references UNP:P12497, focusing on integrase (len=287)

>sp|P12497|1148-1435
FLDGIDKAQEEHEKYHSNWRAMASDFNLPPVVAKEIVASCDKCQLKGEAMHGQVDCSPGI…LLWKGEGAVVIQDNSDIKVVPRRKAKIIRDYGKQMAGDDCVASRQDED

Why should these sequences be so different?!

and in case you think I'm focused on a bit of noise: there are 42 other HIV integrase structures all referencing UNP:P14350, and 43 other structures referencing UNP:12497 (and 79 others referencing UNP:Q76353, very similar to UNP:12497), 22 referencing an entirely different UNP:Q72498.


texts: Non Coding DNA and its effect on evolution

texts:
I had a discussion with a friend of mine; from his understanding, bacteria and other small organisms have higher amounts of "coding" DNA and, as such, are able to evolve much faster than organisms like us.  His argument was that if bacteria are able to evolve so much faster than us, then they should have become the Apex Predators on Earth instead of humans.

I argued that the 2% of the "coding" DNA is probably as long as the 90% of a bacterium (I'm guessing at this point) and that it is the bacterium's small life span that makes it evolve so fast.  Was hoping to get clarification from someone with more experience in the field.


texts: Are the human genes' promoters all known?

texts:
It seems to be a basic question, but I couldn't find a certain answer.

The human genome is known for more than a decade, and is available through several data providers as the NCBI etc. For the genes' promoters however there seems to be much less information. There are some characteristics known (like the TATA box, which appears in ~25% of human genes), some prediction methods (like CpG sites appearance), some rough estimations for the location (100-1000kbp long, in the adjacent 2kbp upstream from the TSS), but I couldn't find any data set with a closed list of human genes' promoters.

Is this really yet to exist?


texts: Why do I see different hues of colors between each of my eyes?

texts:
Frequently, I see colors with a slightly different hue when looking through my eyes individually. The right eye is more red-tinted ('warmer' hued) and the left is typically more blue-tinted ('cooler' hued). However, sometimes I can't notice any difference in hue between the eyes (even when closing the other) and on a very rare occasion the warm/cool differentiation is switched (left is warm hued, right is cool hued). Numerous others have confirmed they've experienced similar patterns.
My questions:

What causes this differentiation between eyes?
What would cause the hues from being sometimes clearly noticeable and other times non-existent? Is the cause potentially environmental, behavioral, physiological, chemical, etc?
I wonder if this is occurring at the eyeball level (e.g., cone physiology) or somewhere in my brain (e.g., PVC in the occipital lobe)?


texts: Which statement is incorrect for Rubisco?

texts:
My question is this:
Which of the following is NOT correct for rubisco?

a. It is the most abundant enzyme
b. It catalyzes two different reactions
c. It is involved in photorespiration
d. It is not used by CAM plants
e. It is not efficient in fixing CO2

My issues with picking one are because:

a. It is the most abundant enzyme due to its inefficiency
b. It catalyzes both oxygenase and carboxylase
c. It binds O2 meaning its responsible for photorespiration
d. Malate eventually provides a molecule of CO2 to the calvin cycle where it is bound to rubisco, meaning it is used by CAM plants.
e. It only fixes 3 molecules of CO2 per second, making it inefficient. The only reason why this doesn't matter is because of the abundance of rubisco.


texts: Will the interaction of two proteins vary across different tissues?

texts:
Suppose protein A and B is both abundant in tissue X an tissue Y. Will A and B interact in X but not interact in Y?

I guess A and B could be biomarkers of a certain disease, and in the pathological tissues their amount remains relatively unchanged but no longer interact, thus losing their functionality and causing the disease.

One possible condition would be that A and B don't interact directly but require a third protein C to act as the scaffold to form the complex A-C-B. So when C is expressed in tissue X but not in Y, we would observe this phenomenon.

Are there other mechanisms or examples?


texts: Is far Infrared heaters in the market truly producing healthy far Infrared and is it practical to install them at home?

texts:
I read few blogs and websites about far infrared heaters and all are very possible about this new technology. I bought one of the heaters as a test and find quite impressive also.

However, I am concern about long term health effect. I know, there is no health effect of far infrared but the Heater that is producing infrared, is it truly producing only far infrared?

This business is not regulated so What Type of test (or certificate) the heater has to pass before coming in the market?

I am planning to install this heaters in my whole apartment, anyone has experience to live in a flat/house with far infrared heater? if then can you please share your experience? Is it medically healthy?

Thank you very much.


texts: Can anyone identify this bird - small flock in ireland?

texts:
I saw small birds in a flock of about 6 or 8.

Here are details that can be seen on my best photo - The beak looks pointed and also the legs are quite long and the eye has a bar across it.

I have a recording - how do I share it??


texts:
I've gotten interested in the science behind in vitro meat, and I was wondering what would be necessary to create it. Would you initially need a primary culture, or an immortalized cell line? And how would you go about creating such a culture that differentiates properly?

The closest analog to this, I think, would be tissue regeneration but I'm finding it hard to figure out the answers to these questions.

Thanks so much!


texts: short-day facultative plant, abrupt change to photo period

texts:
What happens biologically to a short-day facultative plant that is a few weeks into its short day (flowering) photo period and is suddenly given a 24 hour period of light? Does anything change biologically after one day of long day (vegetative light) or  will it take several days?

If there is any biological change that is of concern what can one do to try and alleviate any negative affects?

https://en.wikipedia.org/wiki/Photoperiodism -


texts: Why are some human injections intraperitoneal?

texts:
In humans, what benefit do intraperitoneal (IP) injections(old/cheap rabies vaccines, or cancer related injections) offer versus traditional intramuscular injections?

For example, where I live, the rabies are not administered right away after a bite because of the associated discomfort(cheap IP injections) or cost(newer intramuscular injections) they represent versus the low probability of a dog having rabies and the long incubation period(instead, the offending dog is observed carefully for 10 days to decide, or the vaccines are administered in the fourth day if not found). So, since speed of action doesn't seem to be an important factor, what are the benefits of IP injections?


texts:
How many cells are there in the apical meristematic tissue?

Looking at this picture...

, I would tend to think that there are few hundreds cells in the meristem tissue. But I guess this is a picture of a root tip and the answer will be much different if we look at big branches and big trunks of roots. Also, the answer will probably differ between monocots and eudicots.

Roughly speaking, how many cells are there in different apical meristematic tissues (root, branches, trunk, different species)?


texts: Are there multiple meanings to "clone" as in "clone a gene"?

texts: I originally thought that cloning a gene meant to put it into bacteria and have them express it. But sometimes I see it used and it seems like it's just a synonym for "identify the sequence and/or location of". So what does "clone a gene" really mean"


texts:
Why higher plants lack centrioles?
Why do plant cells not have centrioles?


texts: Why do we use klenow fragment in pyrosequencing?

texts: Why do we use klenow fragment in pyrosequencing instead of polymerase


texts: In local newspapers there was a not so recent story about wheatgrass juice being "curative" in thalassaemia. Although I do not take the article at face value, it would be enlightening to know if there was any basis at all in the claims that wheatgrass juice or extract can help mitigate some symptoms of thalassaemia.


texts: Which ionic channels of Pacemakers can work in very low frequencies in extrasystole?

texts:
At frequency 0-3 Hz.
Like computer processors which can work at low frequencies and controlling under- and overvoltage.

Normal most significant channels are Ca2+ and K+ that are changing.
However, I am not convinced that they can work with such a low frequencies.
There must be some other channels that are triggering the extrasystole on.

Which ionic channels of Pacemakers can work in 2-3 Hz triggering extrasystole?


texts: What initiates primase to add an RNA primer to a DNA strand and what makes it stop?

texts: What initiates primase to add an RNA primer to a DNA strand and what makes it stop adding RNA nucleotides? Is there tags added to the DNA back-bone?


texts: Can the body of any organism on Earth live without impairment both in vacuum, and within Earth's atmosphere?

texts:
I know from reading that a human in vacuum needs a space-suit to survive.

Is the body of any organism on Earth capable of living equally in vacuum, and on/below Earth's surface within the atmosphere?


texts: What does "novel, predicted deleterious, within autozygome" mean in genetics?

texts:
I am a medical student and just got involved with a genetic lab and research. I read a lot phrases like: "Although no mutations have been reported in this gene, we think this variant is interesting because the nature of the variant (novel, predicted deleterious, within autozygome).

Can anyone explain it to me?


texts:
I am studying the human circulatory and respiratory systems to develop tools for automated diagnosis of disease.

During the past year, I have read basic books about respiratory physiology, electrocardiography, etc.

At the moment, I feel that my lack of understanding of basic cell biology is prohibiting any further progress. I would like to find a very introductory book on cell biology, which would teach me

what kind of cells there are in humans, what are they made of, and what are their main components
basics of cell cycles, how cells are studied, how they look under the (various kinds of) microscopes
etc

The ideal text would probably be on the undergraduate level and not be much longer than 300 pages. Any suggestions? So I just want to find something to start with.


texts: Can we say it's hybridisation if it's the same species?

texts:
If we mixed two population of the same species into the same environment and then they reproduce together, can we say it's hybridisation?

The wikipedia definition is the following:

  Hybridisation (biology) the process of combining different varieties of organisms to create a hybrid


texts: Aren't antibiotic resistant probiotics dangerous?

texts:
Multidrug resistant probiotics are often recommended by doctors in various cases. But since bacteriae can easily exchange genes by conjugation or other means they could promote the drug resistance of other dangerous bacteriae residing in the bowels. (Which could be just "visitors" otherwise causing infections somewhere else)
Or there is something that withholds this transfer? I think not and so my former genetics professor.


texts: What help does goosebumps do to us? I don't think it helps us noticeably when we are scared or shivering.


texts: Why does flu vaccination only work against specific strains?

texts: I was wondering why the flu vaccination doesn't protect us from all different types of flu. I know there are 3 major groups A, B and C and they mutate really fast. For example Influenza A virus has 2 different proteins on the surface hemagglutinin (H) and the neuraminidase (N). There are 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes. So if they produce a vaccination which covers 187 of the virus (from H1N1 to H18N11) wouldn't it mean that the Influenza Type A could be eradicated from the world ? And wouldn't it work the same way for Type B and C?


texts:
I have been developing LED grow lights for a year or so and one of the things I am trying to do is to build a grow chamber where I can control temperature, humidity, light intensity and quality and levels of $\ce{CO2}$ and $\ce{O2}$.
I don't have any problems with most of the variables except the gases. I can inject $\ce{CO2}$ and monitor the gas, but as the chamber is hermetically sealed, how do I get rid of excess oxygen produced by the plants? Is there something similar to the $\ce{CO2}$ scrubbers used in aquariums? As a matter of fact, plants also need oxygen for their metabolic processes occurring during darkness, but they produce oxygen in excess of this requirement during the day. It is the excess of oxygen the one I want to extract, and not the whole amount of oxygen in the air of the chamber.
The whole idea is that through the chamber, I can adjust light conditions to each crop based on performance. Gas exchange is an important proxy for Chlorophyll fluorescence and has shown a good correlation with performance.
Any ideas?


texts: Can anyone identify this spider? Found in Italy

texts: My cousin found this spider at his place. He lives near Milan, Italy, in a small town. It's a humid region, around there the are a lot of fields but it is a 15 km from the city. It's still hot in these days. He told me that in the picture it seems a little bit too yellow. In reality it is more of an orange shade. He has never seen anything like that around there. Any clues?


texts: How is the recipient's probability of survival calculated in Hamilton's Rule?

texts:
This is Question 99 from the 2012 USABO Semifinals Exam:

Assuming that "snonting" is an altruistic behavior that is maintained due to kin
selection, consider the following situation:

A reproductive male, X, lives with his mate near his parents. His other
siblings are all females and no longer live nearby. Based on your observations,
you know that X is likely to produce 12 MORE offspring during his life. His
parents, however, are older and will only produce 3 more offspring during
their lives. One day, a situation arises where X’s parents have a 50% chance of
death. However, if X snonts, his parents will survive with 100% probability.
Given this information, use Hamilton's rule to predict the maximum probability
of death that X can incur in this situation in order for snonting to be favored.

I calculated the answer based on Hamilton's Rule (r⋅B>C), where r = 0.5, B = (1-0.5)⋅3, and C = x⋅12. Solving for x, I arrived at an answer of 6.25% probability of death for individual X. However, the answer listed on the test is 12.5%, which I assume is arrived at by giving the recipient a probability of survival of 1, instead of an increased probability of survival of 0.5. I am wondering which interpretation of Hamilton's rule is more accurate, or if I have misinterpreted the question.
Thanks!


texts: Recombination due to crossover, outcome?

texts:
Garden peas normally have 7 pairs of chromosomes (n=7, 2n=14). Please calculate how many different types of gametes can be produced through the meiotic process if no crossover happens. If cross-over happens regularly, how many different types of gametes can be produced and why?

I have tried the question, I would suppose the answer to be 2 ^ 7 = 128 for the types of gametes that are produced( that is without crossing over).

However, I am not sure what is the solution what is the answer if cross over does happen. appreciate any solution to the problem.


texts: What type of tree is this? (Coyote Hills)

texts: I found this in Coyote Hills, Los Angeles, USA. Please provide the common name.


texts:
http://en.wikipedia.org/wiki/Parasaurolophus#mediaviewer/File:Parasaurolophus_cyrtocristatus.jpg

I cannot tell if the hands have fingers strung together to form a hove, or fingers to grab. I have seen so many pictures of Parasaurolophus standing up, suggesting possible other functions of the arms and hands. I think their arms are long enough to reach their mouth. Ironically, I have yet to find any literature talking about their hands, but lots of literature talking about their resonating chamber. Do Parasaurolophus have hands with fingers to grab?


texts: Does the apical bud grow back after being removed?

texts: My question pertains to the apical bud which asserts apical dominance in plants. After it is removed, apical dominance is lifted, what happens to that part of the shoot after that? Does it stop growing? Can the (previous) apical bud be restored or do other axillary buds take over as the dominant apical tip?


texts: What are the differences between G+ and G- bacteria?

texts:
The distinction between Gram-positive and Gram-negative bacteria is based upon the Gram staining method, that reflects the bacterial wall physical properties.
However, this classification involves also a large number of differences between them. For example, the endospore formation usually occurs in Gram-positive bacteria and also the quorum sensing mechanism is different.

So what are those differences? Which of them are due to the cell wall thickness and membrane(s) composition and which instead to evolutionary divergences?


texts: Is human genome editing more complicated than mice genome editing?

texts: A lot of genome editing trials are being done on mice and rats, but I often read that the step from mice- to human genome editing is complicated. What are precisely? I guess it has something to do with human's more advanced immune system, but I would like to have a better general understanding of this.


texts: About the mechanism of coupled reaction/metabolism with ATP

texts:
I am not in the field of biochemistry so this may be a rookie question or misconception.

I heard occasionally about the energy "released" from ATP hydrolysis fueling (endergonic) biological reactions. I am concerned about how does the energy "released" actually "fuel" another reaction mechanistically. In chemistry and physics, you can say that the fact that energy is released is a sign that the process (ATP hydrolysis) is energetically favorable (more stable bonds are formed as some weaker ones are broken). Subsequently, when the released energy is heat for instance, this heat can be used to do (or "fuel") mechanical work (like in a car engine). This is intuitive to me but the same cannot be said with ATP hydrolysis. How does the release of energy from ATP-hydrolysis actually "fuel" other reactions? or is it a misuse?

Thank you so much.


texts: I found it on my door. I live in Southeast Texas. What is it?


texts: How are the axons in the white matter bundled?

texts:
I wonder if the following question concerning the axons in the white matter does make sense.

It is common knowledge that white matter is "composed mainly of bundles of myelinated axons" resp. is "mainly made up of myelinated axons, also called tracts" (= "bundle of nerve fibers (axons)".

For the following to make sense the following assumptions are made:

All axons making up a bundle are of approximately same length $L$. (Of course not all axons have the same length!)
Axons run in parallel as long as possible.
Axons normally don't branch inside the white matter. (Or is this a totally unrealistic assumption?)

Assume that it is a sensible definition of a bundle to be the set of axons running densely packed inside a virtual tube of length $l = \alpha L$, $\alpha < 1$. By this definition sub-bundles of a bundle would also be bundles, so we are interested only in maximal bundles.

It's important to notice that the definition of bundles depends on the parameter $\alpha$: smaller $\alpha$ means the axons must run in parallel only for a shorter distance (compared to their common length $L$), larger $\alpha$ means the axons must run in parallel for a longer distance. Smaller $\alpha$ means less but larger bundles, larger $\alpha$ means more, but smaller bundles.

Note that each bundle (independent of $\alpha$) defines two specific cortical regions (the two regions of the source and target neurons of the axons). For the smallest bundles (largest $\alpha$) their diameters correspond well to the size of the source and target regions (see picture below).

See here different partitions into bundles with $\alpha \approx 0.5$ (grey, 1 bundle), $\alpha \approx 0.75$ (blue, 2 bundles) and $\alpha \approx 1$ (red, 4 bundles):

For the sake of simplicity, assume that - for a given $\alpha$ - bundles don't overlap, i.e. each axon is contained in only one bundle. (This might be an oversimplification.)

My question is:

  Can a rough estimate be given, how many bundles with a given number $N$ of neurons are there in the white matter (for a given $\alpha$)? (Choose the organism you like or know of.)

I suppose the largest bundle to be found in the brain is the corpus callosum which - as a tube - has a rather short length (small $\alpha$). It contains (in the macaca nemestrina brain) about $10^8$ axons.

For the sake of simplicity, let's consider only powers of ten. Then for a small $\alpha$ which would allow the corpus callosum to be a bundle, we will get as a "null hypothesis" (with purely hypothetical numbers of bundles!):

But maybe the distribution is somehow bimodal, e.g. like this:

Is a reliable answer to this question out of reach today? Don't we know enough about the long-range structure of the white matter? Or did just nobody take the effort to make this statistics? Or can I find it somewhere?


texts: How does the OD correlate with the number of algae cells?

texts:
My research team and I are using a spectrometer to measure the OD of an algae sample. We are trying to answer the question "Is there a correlation between OD and the number of algae cells?"

What should we consider in our experiment? Is this an established technique?


texts:
I am trying to learn the interactions that hold the hemoglobin tetramer together, and the conformational changes induced at various allosteric sites. So far, what I know is this:

The tetramer can exist in relaxed state (R-state), or tense state (T-state).

The R-state favors oxygen binding, while the T-state favors oxygen release.

At the C-terminus (a histidine residue) and the 40th residue (aspartate) of the β-chains, and the 146th residue (histidine) of the α-chain, there are two salt bridges. When red blood cells are present in tissues (with a pH of 7.2), the formation of both bridges are favored. When both bridges are formed, the T-state is favored.

The second residues of the β-chains are also a histidine. (This is near the N-terminus). This residue participates in an ionic bond with 2,3-BPG. At the 82nd position, there is a lysine residue that also participates in this bond. (This is a little over half-way down the amino-acid sequence). By binding 2,3-BPG, the T-state is favored.

On the binding of oxygen to a heme-group, the iron atom moves to the center of the protoporphyrin ring. Attached to the iron atom is yet another histidine. This histidine is attatched to an α-helix that is attached to the terminal-carboxyl of the α-chain. By moving the α-helix, a conformational change is induced in the other subunits to shift the structure to the R-state.

What residues of which subunits are the α-carboxyl termini in close spatial relation to, and how does this movement induce the R-state? And which residues hold each dimer together, and how do they affect the R- or T-states?


texts: Is the medium which transmits the electrical impulse through the heart different to a nerve?

texts:
According to Nerve

  A nerve is an enclosed, cable-like bundle of nerve fibres called axons

Being an Axon

  An axon (from Greek ἄξων áxōn, axis), or nerve fiber, is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials

In the other hand,

Electrical Conduction System of the heart

  The electrical conduction system of the heart transmits signals generated usually by the sinoatrial node to cause contraction of the heart muscle.

The conduction system consists of specialised heart muscle cells

Is this conduction system consisted of cells (which I assume also transmits electrical signals through axons) different in nature to nerves?


texts: What percentage of human excrement is toxic if ingested?

texts:
I have been considering food production, waste management and 3D food printing, particularly during space exploration. This led me to wonder if human excrement could be processed into raw materials for printing healthy food.

What percentage of human excrement is considered toxic to humans if the toxins were ingested in the quantities in which they were excreted? I am referring only to excrement produced by humans not infected with diseases of any kind.


texts: Exercise causes number of cell divisions to approach Hayflick limit faster? And hence shorten life expectancy?

texts:
A world class athlete spends a lot of time performing intense exercises.  Correct me if I'm wrong, but I assume that these intense exercises causes significant damage to the athlete's cells, but with proper nutrition, they are able replenish these cells with stronger ones.   This process of destroying and re-creating cells causes cell divisions to approach the Hayflick limit faster, and hence shorten the athlete's life expectancy.

I also heard that caloric intake causes the number of cell divisions to approach the Hayflick limit faster.  World class athletes generally consume substantially more calories than the average individual, which also contributes to a shorter life expectancy.

So for this reason, is the life expectancy of world class athletes generally shorter than the average individual? And what about casual athletes?

Edit
If world class athletes live longer lives than the average individual, why is this so despite performing activities that expedite the deterioration of telemeres, and hence, approach the Hayflick limit faster?


texts:
On my farm a few weeks ago I started to see a large insect(?) I never, in my 76 years, seen before.

It is bright yellow, about the size of a man's hand, flies not like a bird but more like a butterfly and its large long legs hang down in flight. Observations are from 75 yards away.

The encounters are too brief to get a picture or even a magnified view without stationing myself in position all day.


texts:
We know that software tools like I-tasser etc have a web server and a standalone option too. Is there any difference to protein C-scores or efficiency or accuracy if you do it on standalone instead of web server?

What would be the difference if I use the Web server instead of dedicated server for protein modeling and docking?. Available from: https://www.researchgate.net/post/What_would_be_the_difference_if_I_use_the_Web_server_instead_of_dedicated_server_for_protein_modeling_and_docking [accessed Apr 27, 2017].


texts: Can men also become only bald on their legs?

texts:
Often hair loss that primarily affects the top and front of the scalp will happen to men (and female) during aging. Male pattern hair loss is believed to be due to a combination of genetics and the male hormone dihydrotestosterone.

Men with androgenic alopecia typically have higher 5-alpha-reductase, lower total testosterone, higher unbound/free testosterone, and higher free androgens, including DHT.

The question is whether this kind of balding is only present in the hair of the scalp or can this proces also happen on the legs (or other parts of the body)?


texts: Since frogs are ectotherms and supposed to have low metabolic rate, why do they grow so fast and eat so much?

texts:
It's always emphasized in literature that endothermy enables high growth rates but requires more food.

But look at frogs, for example: bullfrogs, toads, pacman frogs etc. They would readily eat a quarter their weight a day, and they grow real fast (I used to keep pet frogs: pacmans, for example, become more that twice as big in one season). And all of that despite being ectotherms. How is that possible?


texts: Are a bonsai tree and its normal version the same species?

texts:
I would like to know if bonsai type of a tree is a separate species from its normal version. Do they differ by genes, or is it just a matter of different physical care?

Can I grow a bonsai tree from seed of a normal outdoor tree (of course, I understand that not every species will endure being dwarfed)? Can I grow a normal outdoor tree from some seeds labeled "bonsai"?


texts:
I know that the part E in this graph is definitely the part of refractory period.

My question : Will there be any effect on B,C or D if a stimulus is given at  time B,CorD respectively ?


texts: How do harsh conditions cause an increase in the male birth ratio?

texts: I've heard that in harsh conditions more human baby boys are born than girls because a bigger ratio of them will die before reproductive age. But in which aspects of the random gene combination while conception can harsh conditions (and which of their characteristics) actually can make a difference?


texts:
There are tons of soil, rock, etc. being dug up, dug into, and moved all around the world each day. Paleontologists likewise regularly excavate fossils and both buried and frozen specimens, and biologists take samples of permafrost, soil and underground bodies of water.

Given all of the upheaval of these ancient and underground substrates and specimens, I'm wondering what the odds are that we unearth a superbug?

by superbug, I mean an otherwise unknown microorganism that modern medicine does not have a way to kill.

I understand that this is likely too broad of a question to be answered here (but feel free to try!), so I will break this down into a more relevant set of questions to inform my research.

How many microbes (# of species and/or density) typically exist in a cubic meter of soil? (or some other volume)

This article seems to be a good start.

Do these microbe abundances and diversity change with depth?
What is the deepest place in the crust that has been found to harbor life?

This article from 2010 suggests almost 1400 meters. Have we found deeper?


texts: What would happen if there were no more spiders?

texts:
In an office conversation about arachnophobia, one colleague declared "they're hoorrible and they should all be killed". He doesn't like spiders.

I've heard of the scenario where bees die out quite a lot, sounds like that would be pretty catastrophic.

So what would happen if suddenly there were no more spiders?


texts: How does a smoker's finger or mustache get yellowish by nicotine?

texts:
Tobacco use is the leading cause of preventable death around the world.$\ce{^1}$

The stain is considered as a "tell-tale" sign for identifying smokers. Multiple materials stated that it's due to tar (nicotine) disposition. The colouring fades away after the smoker quits. There are also number of search results that point to "removing" these smoking stains in the skin. If it can be removed using chemicals then I wonder what sort of a chemical it utilized there as well.

Is it only nicotine that causes the yellow stains on the skin? What is the role of oxygen deprivation in this scenario? Can this be categorized under smoker's melanosis? What tissues/cells are being "transformed" in this case? What's the biochemical explanation behind the colouring of skin?

How is this staining differe from a ink stain in the skin which lasts for about about 3-4 days?


texts:
I'm looking for suggestions as my internet searches aren't turning up much.

I'm trying to find a plasmid that has the pBR322 origin, as it's low(ish) copy number and can tolerate large inserts. Additionally I need the plasmid to be inducible with a system other than the pBAD setup (e.g. IPTG would be fine, but if there is one that is more tightly repressed that would be preferrable as IPTG is leaky).

Lastly, I could do with it having a potentially obscure resistance cassette, but this is less of a problem.

Any help appreciated.


texts: How can I find the most studied SNP of a gene?

texts:
How can I find the most studied SNP of a gene and diseases that the most studied SNP has been related to?

I search in dbSNP database but I can't find it.

What is the process?


texts: Why does NaCl react differently with a boiled potato and with a raw one

texts:
Well my question is based on this question down below.

For those who don't speak german:

You have two potato slices one of them is boiled the other one is just raw.

Now you scatter some salt over both surfaces of the two different slices and wait about one hour.

After the time is over the salt on one potato isn't in his crystalline formation anymore.

So my question is why are behaving both slices different?

My guess is that the carbohydrates ( Starch ) reposition and the starchcores bind with H2O.
So the H2O binds with the NaCl?

I would really enjoy it when somebody could tell me the chemical reasons why this happens.


texts: Why such diversity in sexual dimorphism in passerines?

texts:
In searching for info to answer my question, I’ve found a fascinating 1998 article  by Owens and Hartley from Proc. R. Soc. Lond. B. It reports such cool findings as that

  When we break up plumage-colour dimorphism according to whether it is due to melanins, carotenoids or structural colours, we find that each category of plumage-colour dimorphism shows a different pattern of covariation. The correlation between overall plumage-colour dimorphism and the rate of extra-bond paternity is due to structural colours, whereas melanin-based dimorphism is associated with sex differences in parental care.

Intriguing, but not on point for my question; so I turn to StackExchange.

Is it known why, for example, northern cardinals (Cardinalis cardinalis) are essentially monomorphic in size but dimorphic in plumage color, American robins (Turdus migratorius) and blue jays (Cyanocitta cristata) are pretty much monomorphic for both traits, and the sexes in the brown-headed cowbirds (Molothrus ater) vary so in size and coloration that they could easily be mistaken for separate species?

Whether it involves caring for young or pair monogamy or whatever, how does one species arrive at a particular morphological-behavioral complex while another ends up someplace entirely different? Is that entirely a matter of evolutionary contingency?


texts:
I have a lab question that is confusing me. Just to be clear this is a homework question but I've done some extensive research and can't find what seems to be a "good" answer.

The question is this:
List the steps in order that need to be taken between gel electrophoresis band excision and MS?

The only things I can think of are cleaning the salts out of the sample if salting out was used and removing any detergents that were used like SDS. The question seems to imply that there is a specific order or steps required leading me to think there is something I am missing. Any thoughts appreciated.


texts: I was just wondering if anybody could help me identify the trees in this image? I am confused as to whether they are aspen or birch, a mix of the two, or whether the brown/reddish trees are some other species I don't know about? Thanks!


texts: ClustalW and Omega of EBI and Blast of NCBI, both globally align sequences. Smith waterman of EBI aligns sequences locally, but works with just two sequences. How can I align more than 2 sequences locally?


texts: How do we explain the white feathers of an albino peacock?

texts:
Peacock feathers are supposed to produce colours by surface structures modulating the light (in addition to the usual absorption/reflection mechanism)... https://en.wikipedia.org/wiki/Structural_coloration

But how does that explain the existence of an albino peacock? https://www.favrify.com/wp-content/uploads/2015/02/peacock1.jpg

Does albino mutation change the physical structure of feathers in addition to the lack of colour pigments?

Does anyone have a close comparison of the physical difference of the albino vs coloured peacock feathers?


texts: How do we know that our genetic similarities to other species is actually due to common ancestry?

texts:
I know all about how the fossil record shows more human-like species coming about over time, and how modern testing proves we have genetic similarities with other animals.

All that says is we have similar genetic blueprints to animals in the past and present. How do we know these similarities are caused by having a common ancestor?


texts: Statistics: How are protein species distributed over cell types?

texts:
There are roughly 10,000 to 20,000 protein species in the human proteome (while I've seen also numbers of 500,000 to 1,000,000). Furthermore, there are roughly 200 different cell types in the human body. My question is:

How are the protein species distributed over the cell types?

This means specifically:

How many proteins are expressed by n cell types?

How many cell types express n proteins?

Probably these numbers are not known exactly because not all the proteins may be known that a given cell type expresses.

But there might be evidence which general form the two distribution curves do have. Are they Poisson distributions and do look more like this?

Or this?

Or that?

Or some other kind of distribution, e.g. Gauss or even multi-modal?


texts: What absorbs light at 380 nm in a sample of DNA oligonucleotide extracted from a PAGE gel?

texts:
I have extracted DNA oligonucleotide of size 77 bp from a crushed 10% PAGE gel using 3 rounds of $\ce{LiClO4}$ in water. The extracted elute was dried down in a vacuum centrifuge to a certain volume and then precipitated with 5 volumes of Ethanol before taking a spec on a NanoDrop. I do have a significant peak, characteristic of a DNA oligonucleotide, at 260 nm with a $A260/A280 ≃ 1.75$.

However, I also get a peak at 380 nm. I used to get this since a long time but I could not understand what it meant (did not find any literature reference). I do not want to worry about it too much, as long as I have my oligo, but I would like to know what it is. A colleague of mine also got the same peak, though not very prominent, who did not do a PAGE purification but direct UV Spec after Phenol/Chloroform extraction and $\ce{LiClO4}$ in acetone precipitation.

What would you suggest?

[Note: For your information, I have already asked this question here on ResearchGate. Out of all the answers, Paul's seem to be quite rational. However, I wanted to see if anyone has any other opinions]

Thanks a lot for your answers.


texts: How are the helices of MscL gating "attached"?

texts:
I'm attempting to model the mechanosensitive channels of large conductance (MscL) in E. coli for finite element analysis purposes. I have a number of papers where this has been done, and one shows the modelling with van der Waals forces (as seems logical), but is it known how/where these forces exist?

For references, two papers I'm using have videos and pictures:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0183822#sec013 (see the movies S1 & S2)

https://www.cell.com/action/showFullTextImages?pii=S0006-3495%2806%2971838-0


texts: This Guidebook is called "How to identify mushrooms to genus VI". Some other editions/versions of it say "Genus III" or "Genus I". What does this mean?


texts: When does meiosis occur in flowering plants?

texts: At what point does meiosis occur during the development of a flower?


texts: How many animal species are larger than humans?

texts:
I sometimes think about just how huge humans are in comparison to most animals. Even compared to a squirrel, which is really a pretty large organism in the grand scheme of things, humans are hulking giants.

I know humans are classified as megafauna, but we're neither the smallest nor the largest animals in that group.

How many animal species currently exist where the average adult individual is more massive than the average adult human?

Sources that cite other measures of size, like height or length, might be useful, but I would expect the focus to be on mass.

Obviously, new species are being discovered all the time, and we don't have exhaustive measurements for every species, but considering how few megafauna there are, I would expect a fairly accurate estimate to be possible.


texts: How was the cama's life expectancy computed?

texts: A cama is a hybrid between a male dromedary camel and a female llama. The first cama was born on January 14, 1998, yet on the Wikipedia page it is said that a cama's life span is 30–40 years. How was that number determined? Is it simply the average between a camel's and a llama's life spans?


texts: Why is GTP, not ATP, produced in Gluconeogenesis & TCA Cycle?

texts: In both gluconeogenesis and the TCA cycle, there is a point in each that GTP is produced instead of the usual ATP. My question is why GTP and not ATP for these 2 specific steps?


texts: Can exhaustive algorithms produce MSAs that are suitable for 3D structure modelling?

texts:
While predicting 3D structure of a protein through homology modelling, the most important step is Multiple Sequence Alignment of template sequences with the target protein whose 3D model is to be predicted. At this step according to my book for Multiple Sequence Alignment, the either T-coffee or Praline software is used; these programs are heuristic in nature and based on a progressive alignment method. There are always concerns regarding the sensitivity and specificity of heuristic  algorithms.

To avoid that problem I imagine one option is to use exhaustive algorithms. During this alignment step, which is very critical in 3D modelling, can we use exhaustive algorithms to yield good models?


texts: Do endosymbiotic organelles have Latin classification?

texts: Do endosymbiotic organelles such as chloroplasts or mitochondria have Latin classification?


texts: Which Geologic time scale is the most accurate?

texts:
I kindly ask to show me some pictures that is a generally accurate geologic time scale.

In google, a lot of geo time scales are different.

On what i have searched there are 2 major eons which are

I.Precambrian eon
 1. Archean eon
 2. Hadean eon
 3. Proterozoic eon

II.Phanerozoic eon

Palezoic
Mesozoic

3.Cenozoic

But along with it Precrambiann is further divided to proterozoic eon, archaaen eon and hadeon eon are ERAS of but it clearly says its an EON.

And how about in Phanerozoic eon?

Kindly please clarify the following. Thank you!!


texts:
I’m trying to find information about this tree that I didn’t plant. Looking for information in terms of pruning, etc.

It had white flowers on it this spring, but is now flower less and has very few young berry-esque type fruits growing on it. They’re very small still, but it seems they’re going from green to a red. This in Michigan.

Additional pictures:

Thanks to Bryan Hanson for the answer! Found a picture online of it with flowers:


texts: Auto-immune problems if immature B-cells released if bone marrow bone is fractured?

texts: A fracture of a bone containing bone marrow with B-cells not yet taught to not recognize self-antigen, if the bone is fractured, can those cells get released and cause problems?


texts: Difference/similarity between adaptive radiation and species divergence?

texts:
I've been reading various answers on different sites but I still don't know whether adaptive radiation and species divergence are different or similar.

My questions:

1) On some sites, it says that adaptive radiation is a form of species divergence, while on others it says that they are different. Which one is correct?

2) Is the main difference that adaptive radiation occurs relatively rapidly and species divergence takes longer?

3) Darwin's finches is used as an example for adaptive radiation, but is it also an example of species divergence?

4) Are the finches on the galapagos islands all difference species (one species diverged into many)? Or are they all the same species, just with different characteristics (e.g size of beak)?


texts: What dinosaurs live during cretaceous period?

texts:
I cant find website that shows all dinosaurs that lived during this time?

Tyrannosaur rex and triceratops I know but what else?


texts:
More tesla = more resolution, is there limit of human body of how much strong magnetic fields it can handle safely which means there is limit to how strong MRI magnets we can use?

Engineering problems aside, could we scan live humans if we had 20 or 40 tesla MRI machine?


texts:
Bought this Fish at the pet shop today. Forgot it's name.
That pink fish


texts: I did a test which involved growing e. coli on a petri dish. I did not dilute the sample, and this resulted in growing hundreds of small, overlapping colonies. However, they still can be counted, but it has been tedious work. Does anyone have tricks for counting small colonies? Also, I've read people will just write >300 if their colony count is too large. Is this data sufficient? I need to compare the colony count for several petri dishes and they all have quite a lot. If i just write ">300" for 80% of my data, it won't be a very good comparison. Can anyone help me out here?


texts: Could somebody please tell what tree genus is this?

texts:
Leaves of a tree in south Asia:
It is in Pakistan, found in flat land habitats.


texts:
Can anyone help me identify what kind of beetle this is?

It's ~1/4" in size and was found on some air-dried hardwood lumber in the Pacific Northwest.


texts: Why do some people have symptoms of salmonella and others not?

texts:
So I was reading from the Mayo Clinic website and they say that typically people with Salmonella have no symptoms, but why?  Why do some people have symptoms and others not?  Salmonella does after all mutate.

Here is an excerpt from the Mayo Clinic Website

  "Typically, people with salmonella infection have no symptoms. Others
  develop diarrhea, fever and abdominal cramps within eight to 72 hours. Most healthy people recover within a few days without specific treatment."

https://www.mayoclinic.org/diseases-conditions/salmonella/symptoms-causes/syc-20355329


texts:
There are a number of methods to "cyclize" an existing peptide:

Disulphide bond as described in Disulfide Bond Mimetics: Strategies and Challenges by Gori et al.
"Linchpin" based (linker chemistry) as described in Synthetic Cross-linking of Peptides: Molecular Linchpins for Peptide Cyclization by Derda et al.

Why would the "cyclization" of a protein be a desirable goal?


texts: Rod and cone photoreceptors are neurons?

texts:
i mean the photoreceptors have axon and dendrite and body cell or it is not neuron
any more   . can we say outer segment of photoreceptor cell is dendrite ? of course these have body cells but i am not sure they are neuron or not


texts: Can the NADPH/NADP+ ratio affect the FMN to FMNH2 ratio in the complex I of the mitochondria?

texts:
This is the reaction:

FMNH2 + NAD(P)+ <-> FMN + NAD(P)H + H+

The reaction works either with NADH/NAD+ or NADPH/NADP+

I know that the NADH/NAD+ ratio affects the FMN to FMNH2 ratio
But does the NADPH/NADP+ ratio affect the FMN to FMNH2 ratio in the complex I of the mitochondria?


texts: Questions about Genetic algorithm paper of Gilman and Ross

texts:
I want to reproduce an (old) biochemistry paper of Gilman and Ross, i.e. " Genetic algorithm selecetion  of a regulatory structure that directs flux in a simple metabolic model."  ( The following link leeds to the paper: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1236362/)
I know this is an old paper, but maybe someone here remembers it. I really need the answers of the following questions because the enzymatic model explained in the paper is very important for my master thesis.

First:
The author defines a system of two ODEs but the initial conditions of these ODEs are not printed in the paper. The author just writes: "Initial conditions for the integration are determined by letting the network relax to steady state. " (see p. 1324 on the lower right) . But how is this meant? In this paper the author wants to optimize the mentioned ODEs , so how can I find initial conditions, when there are not all parameters of the ODEs given?

Second:
On the top of page 1324 are two needstate functions defined, called xi_T and xi_F. When I plot xi(F), the plot looks completely different from the one depicted in figure 3b in the paper. So the function defined in figure 3b) must be wrong. Did anyone realize that error and has a workaround for that? Of course I could define my own functions but I want to stay as close to the model in the paper as possible.

Thank you very much for your help.


texts: I'm looking for a tool to simulate sequence evolution given a specific mutation model and birth-death model. I'm aware of tools and packages like INDELible, Seq-Gen and PhyloSim, but they simulate evolution along phylogenetic trees. What I want is to give a sequence and ask the tool to simulate the evolution of this sequence through N generations. The output should be a big bunch of descendant sequences. I've been thinking about writing such a tool myself, but it's always better to look for something already coded.


texts:
What is the role of triton in buffer for western blot assay?
I understand it has to do with preventing non-specific binding of the antibody.


texts: Are there any social-behavioural differences between the biological sexes in humans "proven" to have an evolutionary basis?

texts:
Long story short: women are from Venus and men are from Mars. But how much of the differences arose from evolution and how much of it comes from Venusian and Martian cultural differences?

Jokes aside, I'm looking for an overview of which social-behavioural differences science has already pinpointed to be rooted in evolution.

update: this article is a great starting point

This question also pertains to psychology, therefore I also asked a related question there.


texts:
There is a lot of contradictory information on baby feeding volumes on the internet. A common claim is that a baby's stomach is the size of a hazelnut or small marble, with a volume of 5-7 ml. But this seems confusing on two counts -

Breast milk contains approximately 0.7 cal per ml, so feeding 6 ml eight times per day would only provide the baby with 33 calories, which doesn't seem enough.
A typical marble is 1/2 inch (1.25 cm) in diameter, which means it has a volume of about 1 ml, not 5-7 ml as claimed.

Are there any authoritative sources on the size of a baby's stomach?


texts:
After HGP, we are not having many databases which consist of several notepad files of ATCG....

Can we distinguish quantitatively a given A,T,C and G stretch as DNA or Gene?


texts: Does osmosis take place in prokaryotic cells?

texts: As far as I know, osmosis occurs in Eukaryotic cells, and I'm wondering if it could take place in prokaryotic cells too.


texts: Why do some yeast flocculate on top an other at bottom?

texts:
When fermenting beer normally after the fermentation has completed the yeast flocculate and drop to the bottom. However occationally they form a foamy layer on top of the beer.

The difference is maybe strain dependent. But exactly what is it that makes the yeast drop to the bottom or raise to the top of the beer?


texts: How does your body know when it is infected so it can invoke a fever?

texts: How does your body know when it is infected with a virus or bacteria so it can invoke a fever or ramp up the immune system?


texts:
What is the difference between genetic introgression and genetic admixture ?
Are these terms interchangeable ?
Do they apply to different population scopes or something ?
The usage seems kind of vague to me.
Looking for some clarification.