texts: Do viruses linger/passively transport or attack the body at once?

texts:
Do viruses generally attack as soon as they can or do they lie dormant until they reach a cozy spot in the body?

Like is it improbable I have inhaled a virus if I do not feel pain in my lungs?


texts:
I have PacBio CCS.h5 and the corresponding fasta and fastq files and I would like to demultiplex them. Does anyone know of how this can be done in the absence of bas.h5 files.

Thanks for your help!

Mandy


texts: Role of processing bodies in mammalian development

texts:
I am currently writing a project proposal for university admissions regarding the duration till which maternal mRNA is required for mammalian development. Till now all the literature I have read has data on P-bodies during oogenesis:-
1) https://www.ncbi.nlm.nih.gov/pubmed/22918798/
2) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2785738/
It will be very helpful if anyone can provide a link for research articles showing p-bodies during embryogenesis in mammals.


texts: Why does human facial and head hair continue to grow?

texts: Many people can grow extremely long head hair and facial hair. Are there evolutionary theories as to why this is the case? It seems like having long hair could be a disadvantage, and extremely long hair seems to be rare in other mammals.


texts: how can a recessive allele become represented in a significant number of individuals in a population

texts:
Darwin believed that individuals that are poorly adapted to their environment are less likely to survive and reproduce. This means that their genes are less likely to be passed to the next generation. Given enough time, a species will gradually evolve.

-individuals in a species show a wide range of variation
this variation is because of differences in their genes

-individuals with characteristics most suited to the environment are more likely to survive and reproduce. The genes that allow these individuals to be successful are passed to their offspring.

In genetic terms, evolution is any change in the allele frequency of a population.

A recessive allele can become represented in a significant number of individuals in a population, how?


texts: Insect Identification question: Is this a flea? If yes, what kind?

texts:
I live in the pacific northwest and I found these insects in the carpet and comforter. I suspect them to be flea based on my image search. But I would like to confirm. Can you also tell me what kind of flea is this?
1
2
3
My apologies for the grainy pictures. These are my attempts at capturing the photo from the microscope's eye piece using my smart phone.


texts:
I've read several fitness articles mentioning redirected blood flow to muscles that are in use. However, they never mention how it works. Is it local and specific to the muscles in use? Or, for example, I guess more blood has to flow through the entire arm if I am training my forearms..? So, won't the entire arm benefit to a certain extent?

I did some research and discovered the vascular shunt mechanism through the opening and closing of capillary sphincters. However, I cannot find any resources discussing how local this effect is. So, as an example, how much does blood flow to the arm improve if someone is training their forearm for six months?


texts: Why are higher doses of atropine required to produce central effects?

texts: Reason given in my book is restricted entry into the brain..is it something to do with the chemisty?


texts: Reason for different color perception in left/right eyes?

texts: What could be the reason for a difference in color perception between the two eyes of an adult individual without any known eye conditions? In particular, a difference in the perceived color temperature in each individual eye and an average of the two when looking through both eyes.


texts: What species is this? Seashell from Indonesia

texts:
Anyone know exactly what species this is?  I gather it may be an auger (family) or cerith (family) of some sort.

This particular one is native to Indonesia's black beaches.

I would like to know what is the genus and species of this specimen.


texts: How is sugar in fruit metabolized, or digested and used?

texts:
I thought before, in general, when we have sugar in our food, then the sugar goes in our bloodstream, and if there is too much sugar, then insulin is secreted by our pancreas, and the sugar is pushed into our cells for storage, and to lower the blood sugar (and the insulin may over do it, causing our blood sugar to be too low).

But then recently I heard that sugar in fruit goes through a different route: it goes directly to the liver, and not moderated by the pancreas and insulin?  How does it work?


texts: largest and smallest gram positive, gram negative and fungal pathogens

texts:
As I stumbled through this question:

  A 16-year-old female patient presented to her family physician
  with a complaint of an abnormal vaginal discharge and pruritus
  (itching). The patient denied having sexual activity and recently
  completed a course of doxycycline for the treatment of her acne.
  An examination of a Gram-stained vaginal smear revealed the
  presence of gram-positive oval cells about 4–8 μm in diameter.
  Her vaginitis is caused by which of the following agents?
  (A) Bacterium
  (B) Virus
  (C) Protozoa
  (D) Fungus
  (E) Prion

I noticed that in order to answer such question, one possible way is to know the diameter range of each pathological group because gram stain can be positive in both fungi and bacteria and so is gram negative.

I have googled and searched but found no such information; all i found was about largest bacteria in general (not pathogenic bacteria) and same for fungi.

It would be extremely useful to know the following diameter range of:

pathogenic gram-positive bacteria
pathogenic gram-negative bacteria
pathogenic fungi
pathogenic viruses

P.S. by pathogenic i mean pathogenic to Humans


texts:
I came across this specimen which I assume belongs toeither the phylum porifera or to the coelenterata.
Can someone please help me identify it?

The specimen was found in Ayodhya, India.


texts: Effect of 2,3-bisphophoglycerate (2,3-BPG) on haemoglobin

texts:
When 2,3-bisphophoglycerate (2,3-BPG) binds to haemoglobin, a higher partial pressure of oxygen is needed to bring about 50% saturation of with oxygen.

What is the physiological significance of this and its molecular basis?

How would this affect the oxygen dissociation curve of  haemoglobin and would it alter the Bohr effect?

Note regarding editing
In its original form this was a multiple choice question that had remained unanswered for a year, possibly because the detractors are very bad. Because the topic it covers is thought to be of general interest it has been reformulated as a standard question. For the record, the original question asked which of the following were correct: (1) 2,3-BPG in red blood cells causes the oxygen dissociation curve to shift to the left. (2) The binding of 2,3-BPG to haemoglobin lowers the affinity of the haemoglobin for oxygen. (3) Binding of 2,3-BPG to haemoglobin reduces the Bohr effect. (4) When 2,3-BPG is absent, oxy-haemoglobin is less likely to unload oxygen. The ‘correct’ answer was given as (2), but the poster thought that (4) was also correct.


texts:
There is a long list of thalamic nuclei which are somehow embedded in the thalamus, a "large mass of gray matter located in the dorsal part of the diencephalon", according to Wikipedia.

I wonder what the nuclei are embedded in:

In a pool of glia cells or of other more or less unspecific "thalamic
neurons"?
Does the thalamus consist mainly of nucleic or of non-nucleic
neurons?
How are the non-nucleic neurons of the thalamus classified?

Edit: In the Scholarpedia article on the thalamus one learns, that thalamic nuclei essentially are relays, and that there are relay neurons and interneurons in the thalamus. Might it be the case, that relay neurons can but interneurons can not be assigned to a specific nucleus (= relay), that means: interneurons build a somehow separate neuronal structure that is somehow interwoven with the nuclei?


texts: Can anyone ID this flower plant by the photo?

texts: Can someone identify this plant? It has big red flowers when it flowers! Not sure if it is native, but it is in my grandmothers garden in Vancouver, British Columbia, Canada.


texts:
As far as I know a virus can infect any cellular organism from a bacteria onwards, including protists, algae, plants, and so forth.
But can a virus infect a virus?


texts:
Self fetilization of F1 dihybrids, following independent assortment of alleles result in:

a) 3/16 Tall-rounds ; 3/16 dwarf-wrinkled
b) 9/16 Tall-wrinkled ; 3/16 dwarf-round
c) 9/16 Tall-round ; 3/16 dwarf-round
d) 3/16 Tall-wrinkled ; 3/16 dwarf-round

This question was asked in MCAT exam in Pak for which I'm preparing this year.... no genetic arcitecture was mentioned in question... The above mentioned is original format of question.... in ans-key, the ans is D but I am confused why it can't be C.


texts: Is it possible to completely puncture a human hand and have no blood come out?

texts: Illusionist David Blaine sometimes performs a trick where he takes a very long and thin ice pick, insterts it in his hand, and comes out the other side (the palm). However, there is no blood present. Is this possible at all? (Warning: Graphic Content) Here is the video (already timestamped)


texts: How are primary monoclonal antibodies for screening mutant cells made, physically?

texts:
I'm working with a fairly common protein expressed in a large numbers of organisms, let's say a keratin-associated beta-protein. I'm trying to develop a process which requires primary-secondary antibody screening for the keratin-associated beta-protein. Trouble is, it's expensive. Very much so.

I can't find the antibody for any less than $778/mL, and after accounting for dilution and volume required for the recommended protocol, I can't imagine I'll be able to finish designing the process with any less than 20mL. The protein can't change as a design constraint, so there's no reason I'd ever need to change my antibody, but if I need so much... is there any way I can make it myself?

How are these antibodies actually manufactured? Would I need to get ahold of actual B cells and use those, or could I isolate the cellular machinery that produces the antibodies and use that?


texts: Does a breastfed infant gain immunoprotection due to intramuscular vaccination of the breastfeeder?

texts:
There is a claim that infants gain immunoprotection from breastfeeding.  I am especially interested in specific protection against pathogens the breastfeeder (not necessarily the mother) has been vaccinated against intramuscularly.

While I know, that IgA and IgM may be present in breast milk and provide passive protection against foodborne pathogens, it is unclear to me, whether there would be any synthesis (and transport to breast milk) of those antibodies without contact between the pathogen and a mucosal membrane of the breastfeeder.  Answer to my previous question suggest that there would be no IgA production as signals received by B-cells in a muscle will lead mostly to IgG synthesis.

I am not asking about the transplacental transport of IgG, only about breastfeeding.


texts: Science experiments at home with Minimal Cost

texts: What is a good recipe for making agar at home for a minimal cost? Are there materials that could be found in the kitchen cabinet?


texts: How precisely can we sense temperature differences?

texts: We have thermoreceptors, thus we can sense temperature (both warm and cold).  I'm interested in the sensitivity of our thermoreceptors - What is the smallest temperature difference that we can sense? I assume that different parts / organs may have different sensitivity (eg. lips vs fingers), thus I'd like to narrow my focus on the palms / fingers. But if someone has comparative data, that is welcomed too.


texts: What did cyanobacteria gain from photosynthesis?

texts: As far as I understand, cyanobacteria began performing photosynthesis long before plant cells as we know them arrived on the scene. But cyanobacteria do not seem to use polysaccharides in the same way as plant cells do (building materials, for example). So what evolutionary benefit did cyanobacteria gain from photosynthesis, that could have made them continue to produce oxygen generation after generation?


texts: How many almonds a day can cause toxicity for vitE?

texts:
Vit E in high doses is dangerous for tissue. How many almonds a day taken regularly can cause this?

RDA
Males : 10mg/day
Females : 8mg/day
Pregnancy : 10mg/day
Lactation : 12mg/day

15 mg = 33IU for vit E

Requirement increase for higher intake of pufa

Pharmacological dose: 200-400 IU/day


texts: Identical twins have the same genetic make up but they differ in development so are they in a way clones?


texts: Medical terminology for asymmetrically-shaped paired body parts?

texts:
Some people have different sized feet [source], a limb that is slightly longer than the contralateral (on other side of the body) limb [source], or other instances of paired body parts being different sizes.
These size differences in paired body parts on the same individual is referred to as hemihypertrophy (or hemihyperplasia).
However, what is the terminology used to describe variation of shape/form of paired contralateral body structures?

In other words, what is the general term for contralateral asymmetry?

For example, some women's breasts are asymmetrically shaped ("breast asymmetry"), and some people's fingers are different shapes (for example, unilateral brachydactyly type D).

 Source: Wikipedia
I assume a term other than "asymmetry" is used, but I have not come across any such generalized terminology.


texts: Alternatives to fittest-win and Moran processes as simple mathematical models of selection

texts:
When modeling selective sweeps as a micro-building block in models of macroevolution (not to be confused with misuses of this in creationist arguments), I use the fittest-win model of selection as a first approximation, or Moran process model when I want a more reasonable approximation.

In the fittest win model the probability for a mutant of fitness r to invade a host population of fitness 1 is 100% if r > 1 and 0 otherwise. In the Moran process model, the mutant of fitness r invades with probability $\frac{1 - r^{-1}}{1 - r^{-n}}$ for a finite population. Alternative in the limit as n goes to infinite, a mutant with r > 1 invades with probability $1 - \frac{1}{r}$ and 0 otherwise.

In general I am interested in simple models of selection of a single (or small concentration of) mutant invading an asexual host population of fitness 1 (with fitness constant and independent of frequency). Are there other common mathematical models for selection of this type?


texts: What is this insect I found in my kitchen?

texts:
So I found this bug crawling around near my kitchen sink. There were two others, but not any sort of swarm. I think they're some sort of insect larva, as they don't have a bunch of legs like a millipede or woodlouse, but I have no idea what kind. There also seem to be several shed shells nearby, if that helps.

As for location this is in the upper Midwest.

Here's the top of the thing, with screwdriver for scale

And here's the underside.


texts: Is Hydrogen rich water safe and beneficial for health ? I just bought a Hydrogen water machine to try and relieve muscle inflammation.


texts:
Today I've heard for the first time of calcium-gated ion channels but find it hard to get an idea how they work, where they are located, and which role they play.

I assume calcium-gated ion channels are just a special form of ion-gated ion channels, which would be a fourth group of ion channels next to voltage-, lipid-, and ligand-gated ion channels (with ligands being some larger molecules). But on ion-gated ion channels even less is to be found on the internet.

One specific paper that mentions ion-gated ion channels is this (Experimental Neurology, 2001)

One paper that mentions calcium-gated ion channels is this (New England Journal of Medicine, 2015)

Where do I find a general introduction into ion-gated ion channels - if they exist?


texts:
First off, I don't know if this is a normal healthy thing to occur. There have been many times where I have an itch on say my arm and I scratch it, only to feel the scratching elsewhere on my body. I assume somewhere along the transit of the touch signals to my brain the signal gets mixed up and is processed incorrectly.

So my questions are:

Why does this mixup happen? (chemical imbalance, damaged nerves, etc..)
How does my brain correspond the touch to somewhere else? (what is the process behind it)


texts: What is the meaning of Sequestered germline?

texts:
What is the meaning of Sequestered germline. I understand the meaning of Sequestered in English but what is its meaning in context of germline.

For eg-"  female germ cells are Sequestered early in development ".


texts:
I study biology at school, and unfortunately for me, my program skips the muscles in humans chapter.

I know (and mainly, feel) that the movement in one direction isn't created by the same muscle as the movement in the opposite direction, e.g the Triceps ("front") and Biceps ("back").

I know that the triceps straightens the elbow, while the biceps contracts the elbow.

I also know that, instead of actually moving the arm, I can contract these two muscles (when I show off, for example...) without actually moving the arm. That area becomes hard. Both muscles, as I feel, are contracting. I cannot statically contract only one of them.

My question is whether this action is something "special", or simply both muscles working against each other, resulting in zero movement?


texts:
Is there a plant (not a microscopic type but one that is visible to the naked eye) that has so much iron (or magnetite), cobalt, or nickel in its body that it can attract a magnet?

In this case "attract" would mean that a person holding a small magnet next to the plant can feel a small attraction between the magnet and the plant.


texts: Can soap kill cockroaches and/or ants? If so, how?

texts: Is it possible to use dishwashing soap as an alternative insecticide? How would that and what are the components of the dishwashing soap that would kill the insect?


texts: Inhibition of beta-oxidation by acetyl- or malonyl-CoA

texts:
Which molecule, in excess, inhibits beta-oxidation?
a. Acetyl-CoA
b. Malonyl-CoA

The answer to this question seems debatable to me, as I think both are correct.  However, according to my professor, only one is correct — which one I  don’t know because it was a question from the final exam.
Acety-CoA can inhibit thiolase, and malonyl-CoA can inhibit CAT I (Carnitine- acyltransferase), both of which lead to the same outcome — inhibiting beta-oxidation


texts: Standard Process Identification of New Disease outbreak Causing Pathogen

texts: Is the any standard procedure or protocol followed for the identification of cause of new disease outbreak(or new pathogen)? Is it different for different countries?


texts: Atomic Force Microscopy Imaging of Proteins

texts:
I was reading about various imaging techniques, and I came across Atomic Force Microscopy (AFM).  It sounds very interesting, and it also sounds like it is capable of imaging proteins (Page 4)

http://www.cma.fcen.uba.ar/files/prepmuestras.pdf

If that's the case, and since AFM can be done with relatively low expense, why haven't more proteins been imaged?  Apparently around 6500 protein structures have been solved via imaging.

If AFM is a viable technique for protein imaging, what would the consequences of using it on a large scale be?


texts: Why is pepsin able to operate at low pH?

texts:
Pepsin is a protease that operates in the acid pH of the stomach. Many proteins are denatured at low pH, and most enzymes — whether or not they denature — require a higher pH for activity.

Why is pepsin not denatured at low pH, and has catalytic activity at low pH, but not at higher pH?


texts: If fully colorblind people only see shades of white,gray, and black, does that mean that the colors black, white, gray are colors humans can’t see?

texts: And since the brain can be tricked to thinking that objects with mostly black and grey gradients are moving, like optical illusions, does that mean motion has a color?


texts: What kind of insect is this? I saw it outdoors.


texts: Seagulls are common. I live on the shore of New Jersey (U.S.), but I have never seen a seagull nest. Where are they?


texts: Questions on adding a protein to a DNA library

texts:
Two questions regarding finding the DNA sequence of a amino acid sequence (AA):

1) If you are able to find out the mRNA sequence of an AA, then don't you automatically know the DNA sequence?

2) When determining the mRNA sequence of an AA, how do you account for the various permutations in the genetic code for a given AA. Ex. Leucine is CUU and CUC. Or does it not matter?


texts: In the diffraction pattern of a protein crystal what exactly determines the intensities of the spots?

texts:
What I have read is that the contents of the unit cell affect the intensities, but how? I am also unclear on why you need to know the symmetry of the unit cell, what is that used for?
I understand segments of this topic (x-ray crystallography) but I am having trouble piecing all the segments together to make a complete picture. I've been spending hours every day on this on this, any help would be really appreciated!


texts: Excretion of various wastes and water requirement

texts: A common fact is that Ammonia, Urea and Uric acid are the most common excreted metabolites and their removal needs varying amount of water, highest for ammonia (hence suited only for aquatic animals) and lowest for uric acid (suited for desert animals). Why is this so? Is it because of different solubility of these compounds in water or their toxicity? If it is the latter, how would excess water reduce the toxicity of a compound? This is a bit over-simplistic question, but I want to understand the tradeoffs involved in selecting the mode of excretion, ammonotelic, ureotelic, uricotelic.


texts: Is there any difference between Tetanus and Tetany?

texts: Both the tetanus and tetany are related to muscle spasms and the latter is due to lack of calcium but is any collaboration between them regarding Clostridium tetani. also?


texts: What were the symptoms of Phineas Gage after suffering his brain injury?

texts:
Phineas Gage was a construction worker who suffered a head injury due to an explosion at a construction site. A metal rod was pushed up his cheek and through his head.

I have heard he demonstrated six symptoms after the accident. What were they?

I have researched this for a while but all I can find is that he was very inappropriate in social situations.


texts:
I have been researching about the ratio between cell membrane surface area and volume.

Obviously, when the volume increases faster than the surface area, and up to a certain point, there is comparatively less membrane for substances to diffuse through and comparatively more organelles that need these substances.

http://scienceline.ucsb.edu/getkey.php?key=5203

The resource above says that "These nutrients then need to get to the center of the cell."

My question is: why do the resources get depleted before they reach the center of the cell? Aren't all the important organelles in the center anyway? For example, wouldn't the glucose go to the center of the cell, and not be used up "on the way"?

And just to be clear, the "center of the cell" refers to organelles like the mitochondria, nucleus etc?


texts:
I use DNA green viewer in Lab to see DNA and RNA bands. Some peers told me it is carcinogenic and is not safe.
Is this correct? If yes, are there better choices to use in working with gel?


texts: Function of NaCl in yeast shuttle prep of plasmids

texts: What is the role of NaCl in plasmid isolation from yeast cells using plasmid rescue solution? If the basic theory behind the method is alkaline lysis, then we is NaCl used and not NaOH?


texts: Why does vitamin D need to be exogenous?

texts:
Vitamin D is a either a hormone or a precursor to hormones. It is very unlike any other vitamins, which are either cofactors or antioxidants, or may be other chemicals necessarily performing catalytic function, just like transitional metal.

But in all sources I found so far it says that Vitamin D doesn't really do anything chemistry-bound, but rather just works as a hormone matching some arbitrary protein receptors or something. E.g. it signals something to the body. But what? And if nothing, then why does not evolution not select out Vitamin D in favor of endogenous chemical or nothing at all?


texts: What's the proper term for "brain waves" read from an EEG?

texts:
An EEG records the electrical activity of the brain. An EEG shows voltage differences as a function of time and shows what have become known as "brain waves".

Is there a scientific/technical word/phrase for one of these measured "brain waves"?


texts: How are isovolumetric contraction and afterload related in the cardiac cycle?

texts:
In the cardiac cycle isovolumetric contraction occurs and causes a pressure gradient. The "afterload" is the pressure exerted on the ventricle from the artery.

Is the afterload the cause of isovolumetric contraction, or what is the exact relationship between them?


texts: Indirect lineage sorting between human, gorilla and chimpanzee, does it exclude loci reversals (for example on chromosome 12?)

texts:
Insights into hominid evolution from the gorilla genome sequence looks at shared genes across human (H), gorilla (G) and chimpanzee (C), and that indirect lineage sorting led to 15% of the gorilla genome being closer to humans, and 15% of the genome being closer to chimpanzees.

In that study or similar studies, is for example the reversed loci in the image below treated as a genetic sequence shared between gorilla and chimpanzee and not with human, or is the specific genes being looked at, so that their position in the genome does not matter?


texts: Does vegetable oil allow methane to pass through?

texts: I'm doing an experiment investigating how temperature affects the rate of methanogenesis. I'm using a peat sample that will be kept in a conical flask connected to a gas syringe with a layer of Janus Green B administered (to indicate if aerobic conditions are present) and vegetable oil (to prevent air entry and to allow carbon dioxide to pass through). There are two main concerns I have about my experimental design at the moment. Firstly will methane also pass through the vegetable oil and secondly one of the pathways of methanogenesis (Carbon Dioxide + Hydrogen → Methane + Water) uses Carbon Dioxide as a reactant, so I'm worried that some of the carbon dioxide produced by the decomposition of acetic acid will be used in the other pathway and not arrive at the gas syringe. Does anybody have any suggestions about making my methanogenesis experiment feasible?


texts: Can you knockout specific receptors in an adult?

texts:
Sorry I don't have a good understanding of this topic, but I'm guessing that "receptor knockout" is related to/a part of "gene knockout"?

And If I understand correctly, gene knockout is currently not yet possible to do in an adult (maybe possible in a small area/specific organ, but not systemically) ?

So does that mean a systemic receptor knockout is not possible and maybe possible in small specific areas?


texts:
I am reading a paper which discusses Maize Genome Structure. Descriptions of the  structure is given in the papers introduction.
I know about heterochromatin "heterochromatin stains intensely, indicating tighter packing. Heterochromatin is usually localized to the periphery of the nucleus"
but, could someone explain what is knob heterochromatin?

thanks for help.


texts: How can we say that a gene is spacio-temporally regulated?

texts: Gene expression is depending on the space and time of the cell. How can we distinguish the function of a gene without a chance of changing its expression? And also how is it possible to find the exact position where the gene is expressed?


texts: Degradation of PMSF in protein extract while dialysing - safe for feeding to animals?

texts:
I would like to use the protease inhibitor PMSF in enzyme isolation. The obtained enzyme diamine oxidase (or better the protein extract) is tested oral on dogs.

According to Wikipedia, PMSF has a lethal dose less than 500 mg/kg, but also degrades rapid in water, which would meet my application. (The half-life is short in aqueous solutions, 110 min at pH 7, 55 min at pH 7.5)

After roughly isolating the enzyme, I dialyse the protein extract for about 12 hours. Is this time sufficient, so that there are no or only small amounts of PMSF in the extract anymore?


texts: My little son just asked me this question. His mother used to complain about the excruciating pain she suffered when she gave birth to him. He is a compassionate kid and wonders whether the hen goes through this pain everyday. Not being a hen, I am not sure if chickens experience pain that is close to the pain associated with giving birth.


texts: Where’s the flaw in my proposed TB Treatment?

texts:
Ten years ago, I emailed a prominent lung specialist with my suggestion for a treatment for Tuberculosis. His lack of response led me to believe that the idea had no merit whatsoever – but I had no idea what the failings might be. I still don’t and I’m hoping someone will enlighten me as to why this is not worth exploring.

The idea is based upon the fact that Mycobacterium Tuberculosis is aerobic – in fact Wikipedia states it “requires high levels of oxygen”. I’d heard that the TB “Sanatoriums” used to practice the treatment of breaking ribs on one side to collapse that lung and “rest” it. It seemed to me that this resting was actually starving the bacterium of Oxygen and killing the infestation.

My suggestion is that we take advantage of having two lungs by inserting a pair of breathing tubes into the respiratory tract and into the head of the two bronchi: it may be necessary to use ultrasound or other imaging to accurately position the tubes.

We feed pure Nitrogen into one tube, and 40/60 Oxygen/Nitrogen into the other – double Oxygen concentration. The patient therefore receives all their Oxygen requirements through one lung. After some period of time, when we judge that the bacteria in the “starved” lung are all dead, we switch the supplies to the 2 tubes and treat the other lung.

Can anyone see why this idea is so flawed?


texts:
How are sodium–potassium pumps distributed over the membrane of a neuron? Where are the most, where are the fewest? Or does this dependent on the type of neuron?

Are there known and understandable correlations between the local densities of  sodium–potassium pumps and other membrane molecules (like ligand-gated or voltage-gated ion channels)?


texts: I have begun to display some of my soft bodied insects and as I am trying to rehydrate some of them that were plump in the abdomen, they appear to have shrunk and the bodies have sunk into themselves.  Does anyone know how to avoid this or what can be done to plump the bodies back up?


texts: Why are lipid-soluble substances harder to excrete?

texts: I understand why water-soluble substances can be excreted. However, why are they easier to excrete than lipid-soluble substances? Why can’t lipid-soluble substance be excreted just as easily in the kidneys?


texts: Why don't phagocytes eliminate mutualistic foregin organisms residing in our body?

texts: Many organisms residing in our body and have a symbiotic mutualistic relationship with our body e.g. organisms in our small intestines. How come our body does not activate an immune response against them? Is it that the organisms have self antigens, or do the immune cells have no antibodies for these organisms? Also, how come our immune system is able to respond to these same organisms if they cause an infection in our body? E.g. Entamoeba histolytica causing amoebic dysentery.


texts: I've downloaded two different reference genome of E. coli (E. coli K-12 MG1655: U00096.1 and E. coli K-12 MG1655: U00096.2) and they have different lengths. I searched for the meaning of reference genome numbers in detail but I couldn't find anything that help me with my question: Why do two different E. coli reference genomes have different lengths?


texts:
My 8 year old son asked me a question I could not answer (and Google, at least in so far as we tried, was no help either).

We were watching a documentary about Salt Water Crocodiles in Northern Australia.

The crocodiles seem very energy efficient: they barely move if they don't absolutely need to (and when they do, it is mostly to eat). Particularly, they hardly ever run, but when they do they are very fast and powerful.

So the question he asked me was: how can crocodiles remain so fit if they don't do any exercise?

If humans just sat around and moved only to eat, ran only when they absolutely had to, our muscles would atrophy. Other mammals seem to be in a similar boat to us humans.

Why not crocs? What distinguishes animals that need to exercise to be strong from animals that don't?

This is the closest question I could find here, but I don't think it assists in answering this question: Do insects' muscles become stronger with exercise?


texts: What is this plant & it looks like USA tree " Carya ovata"?

texts:
I saw this tree in India. It was so fascinating because its leaf looks like Carya ovata, which only grows in the USA & Canada according to Wikipedia:

  Carya ovata, the shagbark hickory, is a common hickory in the Eastern United States and southeast Canada.

Is it really Carya ovata or something else?


texts: Do trees grow from the bottom or the top, or is that oversimplifying?

texts:
I was wondering how trees grow. I wonder if it was similar to hair growth which occurs from the follicle. but clearly branches grow from the trunk so there is definitely a difference with hair growth.

I looked here and couldn't find a verifiable source, there are contradicting answers.

Here it says trees grow from places in places called meristenes, and it denies trees grow from the bottom, but more like from the branch tips and root tips.

If I carve and inscription in a young tree, will it get up with time?


texts: What are the odds of being an albino human and have Down syndrome?

texts:
I know the odds of a human to be an albino. In Europe and the US it is 1 in 20,000 people (source) and for Down syndrome it is 1 in 1,250 (source). So that means the chance of giving birth to a child that has both albino and Down syndrome is:

$20,000 \times 1,250 = 25,000,000$

i.e., 1 in 25,000,000 correct?


texts:
I have a freeze dried culture of staphylococcus aureus; how do I incubate it?

Can I just mix it into Luria broth and just keep it in the incubator?


texts:
Observed to Expected CpG is calculated as below :

Obs/Exp CpG = Number of CpG * N / (Number of C * Number of G)   where N = length of sequence.

I also don't understand the expected CpG which is:

Expected =  (Number of C * Number of G)/ N

Can someone give an example or intuition for the above formula ?


texts: What will happen if there is high concentration of both calcitonin and PTH in blood?

texts: What will happen if there were a high concentration of both calcitonin and PTH (parathyroid hormone) in the blood? In that case, will calcium resorption from bone occur, or absorption from intestine, or deposition of calcium in bones? Also, will blood calcium level rise or fall?


texts: How does the telomere repeat sequence vary in Eukaryotes?

texts:
Question:

How does the telomeric repeating sequence vary in non-vertebrate Eukaryotes? If you know the repeating sequence of a given species I would appreciate hearing it.

Background:

Telomerase is a ribonucleoprotein enzyme that adds DNA sequence repeats to the 3' end of DNA strands in the telomere regions, which are found at the ends of eukaryotic chromosomes.

In vertebrates the conserved telomeric repeating sequence is "TTAGGG".


texts: Are there known genome sequencing issues in E. coli?

texts:
Despite the fact that the human genome project was declared "complete" in 2001, there are even now still gaps due to difficult-to-sequence regions of the genome such as telomeres and centromeres. Only last year was the first entirely complete chromosome sequence produced.
Telomeres and centromeres, however, are specific to eukaryotes.  Are there similar challenges with prokaryotes? A recent publication on a gapless E. coli sequence implies that there are indeed typically gaps, but I can't tell whether this indicates any systematic challenges, as with the human genome.
Thus, my question: are there known genome sequencing issues that currently make it difficult to acquire complete genome sequences from common lab strains such as E. coli?


texts: Will the "frog in boiling water not jumping out" work on warm blooded animals

texts:
There is the famous saying about a frog that is put in water that are slowly boiling will not jump out until it's too late. I realize it happens because of the frog's cold blood that adjusts to the temperature change until it's too late.
Will this work as well on an animal with warm blood, or will the animal jump out ones it gets hot, but not hot enough to cause permanent damage?

Edit due to comments:

Cold blooded animals, like the frog, can adjust easier to their surrounding when the surrounding changes temperature gradually as their body temperature adjusts with the surroundings. Will the same happen to a warm bodied creature, and will it find it easier to adjust to the surrounding if the change is gradual.

For example, I don't like saunas, when I get in them I have problem breathing and I can't stand the heat, which means that I can be in a sauna for a very short time until I have had enough and get out. Will putting me in a sauna at room temperature and then turning it on to gradually begin to heat until its destination temperature will allow me to fill more comfortable and stay longer inside once it's at the normal sauna temperature?


texts:
Are the terms gene expression assays and protein expression assays used interchangeably in molecular biology? Or is it expected of you to differentiate between the two terms.

For example, if I replace the DNA sequence of a gene of interest with the GFP DNA; and then subsequently quantify the fluorescence levels, am I measuring the gene expression of the gene of interest OR the protein expression?


texts: What is the genetic basis of blood type (ABO) system?

texts: What is the genetic basis of the A/B/B+/O/etc. blood type system? Are there definitive loci that correspond to each or can multiple different genotypes produce the same antigen profile? Also, is the blood type of a child necessarily one of the blood types of the parents, or can an A/B female cross to A/B male produce a child with blood type O?


texts: How important is getting enough glucose for maximal brain performance / cognition?

texts:
I know from many studies that have been done, that resting versus active use of the brain has relatively similar overall energy expenditure levels.

On the other hand, however, we know that the brain along with our eyes require glucose in order to function properly. Ketone bodies, lactate, etcetera may act as glucose sparing agents, but certain parts can definitively only use glucose as an energy source.

Anecdotally, I’ve noticed that when performing low intensity mental tasks like jogging or hiking for example, if I haven’t eaten for a while and am in a fasted state, I might get hungry for a bit, but if I just keep on going, after a while I feel fine and can pretty much go on forever after that. With high intensity mental tasks like programming though, the feeling of hunger doesn’t really seem to go away, and if I try to push through it, it just results in consistent brain fog and an inability to perform at any meaningful level.

My theory is that in cases where high mental performance is not required, alternative sources of metabolism provide the needed energy to function, and where intensive cognition is required, the rate of glucose production is unable to keep up with demand from the parts of the brain that depend on it which effectively creates a bottleneck in the cognition process causing the aforementioned brain fog and low performance.

Is this what is actually happening though? I’d like to think that it makes sense, but I’d prefer to have a biologically accurate understanding first and foremost.


texts: What's the relation between Kinase, Phosphatase and ATPase, GTPase (GTP/ATP)?

texts:
I'm wondering what's the relationship between Kinase, Phosphatase, ATPase (ATP) and GTPase (GTP).

For example, when reading online the impression is created that ATPase is a type of Kinase (?). But I can't find any explicit information about it.


texts: Why shouldn't there be any air between lungs and ribcage?

texts:
My OL biology textbook says that one of the functions of the pleural fluid between lungs and pleural membrane is that it ensures no air between lungs and rib cage.

But I wonder why air there would cause any problems. I was told that it'd build up there and exert pressure on the lungs but why would it build up there in first place, couldn't it just go out through the mouth or nose? And in case that's really the answer, how does it manage to prevent any oxygen or other gases from getting into the fluid, after all, the pleural fluid touches the pleural membranes cells which require oxygen, won't oxygen diffuse from around them into the fluid?


texts: How can an animal live without a head / brain?

texts:
The human body is unable to do anything if it loses its head - as the brain is separated from the body, the body immediately dies.

But why does the same not happen to other species or animals? (As they are somehow similar organisms/living things, like humans). However, when the head is cut off from a chicken, snake ( also insects, but it's different system, answered here... I mainly interested in bigger animals) ... the body continues to move. Why and how does this occur? Who manages the functionality of body, if there is no manager (brain)?


texts: What's the real meaning of "brain shrinkage"?

texts:
It is known that some pathologies cause brain shrinkage, for example, it is said that depression causes shrinkage in the hippocampus.

My problem to understand the statement, is that I don't undestand exactly how a brain region shrinks, or what they mean when they say that some pathology causes a brain region to shrink. Does the neurons and everything in them become smaller? Do the cellular membranes become shrink somehow and make the intracellular space smaller? or is it just that a large part of neurons stop firing and they say the brain has "shrinked" because the activity region has become smaller.

Basically, I want to know what happens or what is required in order to have a brain region shrink.


texts: How and why did bats and dolphins develop echolocation?

texts: By how and why, I mean, what factors pushed them to develop echolocation and how did the intermediate stage (before a full-fledged echolocation system was developed) look like?


texts:
I seem to remember reading some time ago about a dinosaur appearing very prominently in the fossil record, with continent-wise distribution. The layer is known specifically for having so many fossils of this dinosaur and might be named as such. Terms "cow-sized", "vegetarian", and "near to extinction event" come to mind. Does this ring a bell?

My memory might be so faulty that it could be an early amphibian, reptile or even mammal!


texts:
Wright's Island model and Kimura's stepping stone model are classic explanations for migration/gene flow o individuals between subpopulations within the field of population genetics.

My question concerns the quantity Nm, the (effective) number of migrants per generation.

In the Island model, where all demes are exchanging migrants at a given time, individuals migrate with a frequency of m, as seen in Wright's approximation for $F_{ST}$

$F_{ST} = \frac{1}{4Nm + 1}$

In Kimura's stepping stone model, individuals can only migrate to an immediately neighbouring subpopulation with a frequency of $\frac{m}{2}$.

My question is:

In the stepping stone model, are there still only $Nm$ individuals migrating, or is it now $\frac{Nm}{2}$?

My thinking is that an individual can either move left or right, each with a frequency of $\frac{m}{2}$, for a total of $\frac{m}{2}$ + $\frac{m}{2}$ = $m$, so that there are still $Nm$ total migrants. Am I correct in my thinking or should it really be  $\frac{Nm}{2}$?


texts: Can anyone identify this grey spotted insect -- is it a tree bug species?

texts: This insect was found in Pune, India near a Bauhinia variegata (orchid tree). I think it's a bug. What species is it?


texts: How can I learn about how cloning works in nature (twins)?

texts:
I would like to learn about how the process of cloning works in nature - how are twins "created" after fertilization what genetic changes can occur in each of the twins.

Where should I start? What are some interesting books on the topic, as well as recent research papers (or just the most important research topics that I could use to start looking for more information)?


texts: What is the role of tracrRNA in CRISPR-cas9?

texts: From what I understand, in a CRISPR cas9 complex, gRNA is comprised of tracrRNA and crRNA.  I've read that crRNA is the part which is matched to the DNA which is targeted, but what role does tracrRNA play in the process?  That I'm not clear about.  Also, unless this should be its own question; how is gRNA prepared with cas9 protein?  Does the protein automatically bind to certain RNA strands?


texts: When we breathe in helium and then speak, our voice changes drastically. Does it happen only due to helium or can happen if we use other gas? What factors of the gas does our voice depend on (like density, temperatue etc.)


texts: Why introduction of an extra copy of a gene related to pigmentation causes RNA interference in Petunia?

texts:
RNAi became famous after Fire and Mello experiment in C.elegans; however, it had been observed before. In the 80's, Jorgensen was trying to increase pigmentation of Petunia flowers by introducing extra copies of chalcone synthetase gene, which encodes an enzyme involved in anthocyanin synthesis.

However, this experiment lead to post transcriptional gene silencing (PTGS) by a mechanism that was not understood at that time, called RNA interference.

Here
you might find more information about the experiment (including the vector used to introduce the gene).

I know how RNAi works by the classical pathway; however, I didn't understand how an extra copy of the gene could generate gene silencing. Introducing of DNA sequences has been used to knock downs target genes, however, generally these sequences are planned so that they will form a hairpin which is recognised by Dicer; probably, the researcher did not use such a sequence. Moreover, exogenenic genes are widely used without resulting in unplanned RNAi.

Does someone know more information about what possibly happened in the experiment to produce RNAi?


texts:
In "The Red Queen", Matt Ridley frequently argues that evolution is a means to an end, without providing much explanation for such a big statement.

Is this a fact in biology? Do species mutate their genes so they can reach an optimum state, like the coelacanth fish that (allegedly) remained unchanged for the last 300 hundred million years?


texts: Why don't all male animals kill a rejecting female?

texts:
If a male animal is sure that the female animal will not reproduce with it, wouldn't it be mathematically optimal for the male to kill the female? (To ensure that no alleles of the "overreact-to-rejection" gene in other males can make use of the female as a reproductive resource)

I might be missing something very obvious here, but I can't seem to see why a gene for "kill-rejecting-potential-mate" wouldn't spread through the gene-pool.


texts: Has anyone ever sucessfully translated xRNA or yRNA?

texts:
I've recently been researching the subject of size-expanded nucleobases in alternative genetic sets. Many papers describe the, at least, partial success in replicating xDNA and yDNA, as well as transcribing them, as suggested here.

  At the same time, studies on polymerase replication and transcription of oligonucleotide sequences reveal that chemical entities other than the typical nucleoside triphosphates can be tolerated to varying degrees.

My question is can the cell's molecular machinery, including ribosomes and tRNA, possibly lead to translation of xRNA or yRNA? Would the translation product yield the traditional 20 amino acids? Have this ever been attempted?

References to original papers would be appreciated. Thanks!


texts:
Is there an agreed definition as to how many nucleic acid bases constitute a gene?

If not, why not? I'm not sure I understand how the exact sizes of genes are defined.


texts: Is this plant with very asymmetric leafes Aegopodium podagraria (aka ground elder)?

texts: I found this plant in a city park in Germany. The leaves were about 20cm of height; the smell of the squeezed leaves was a bit like carrots. The stems were edged. So I guess it was Aegopodium podagraria (aka ground elder), but I'm not sure about it.


texts: Earliest and latest onset of Huntington's Disease(Chorea)?

texts:
Huntington's disease can hit at any age, although it tends to hit middleaged people most often. What is the youngest and oldest person that has exhibited Huntington's?

Clarification: By oldest I mean with no prior symptoms until the age.


texts: How does chromosome fusion get fixed in the population?

texts:
It's well known that one of human chromosomes is the result of fusion between two chromosomes in a primate ancestor. If we put anthropocentrism aside, it becomes clear that fusion events happened a lot of times, since chromosome count varies in different species.

Yet some people claim that while fusion event is probable, getting it fixed in the population is not, because it would require simultaneous mutation in two animals of opposite sex.

Could anyone explain in layman terms the scenario of this trait's propagation? I may only suppose that even if one parent has two distinct chromosomes and another a single fused chromosome, then two chromosomes may attach to the fused one, and then (probably) get fused themselves, thus leaving fewer and fewer specimens with distinct chromosomes in each generation. Is this a viable and likely scenario, or is some other way of propagation more likely?


texts: Solute potential of sucrose relative to NaCl

texts:
Does 1M NaCl or 1M sucrose solution have a more negative solute potential?

I was thinking that for the same volume of solution, (eg 1 dm^3) there will be 2 mol of ions in NaCl solution and 1 mol of sucrose.
However, there are more OH groups in sucrose that water can form hydration shells around.

So which solution has the more negative solute potential?


texts: One of the users on the chemistry s.e. mentioned that when benzoic acid forms in the body in response to other chemicals it might have a mutating effect on one's DNA. Is this true?


texts:
I was recently in Gabon, and I did some long and serious treks with Pygmées into some forest mostly to see Chimps and Gorilla around the Akaka area in Loango national park.
During a trek in forest I took a picture of this frog, it's been a little while now I can't find the exact species of it.

Any ideas guys ?

https://ibb.co/eU4ROk Full sized picture here


texts: What species of spider is this? Could anyone help

texts: This image was taken in assam, India. The size was around 1cm. Could anyone help identify?


texts: Why are recombination rates increasing in mammals?

texts:
I have recently become fascinated with an awesome topic in biology and evolution that I feel is rarely covered in biology courses. That is, rates of meiotic recombination, or the the amount that an organism's genome is reshuffled before it is passed on to the next generation, varies across species! And no one really knows why.
A recent paper by Segura et al which gathered average recombination rates for males across a dozen or so mammals and showed that there is a trend of increasing recombination rate with mammalian divergence.
Why is recombination increasing through mammalian evolution? Is there any reason to believe that there is something special about placental mammals which would drive increased recombination?
There are some catches to this study such as low sampling of marsupials and monotremes and low power for most of species wide recombination rates, ie the average recombination rate of cells in a single individual. But I can see how getting samples from multiple tigers would be difficult.


texts: Is there any evidence of outbreeding depression in human beings?


texts: Choosing appropriate statistical test for ordinal data

texts:
Ordinal response variables show up often in biology, but I'm not sure how they are best analysed. Some examples are qualitative assessments (little, many, a lot) or risk assessments (low risk, medium risk, high risk).

My study is about correlation between pain and depression levels. We are measuring pain on an ordinal Likert scale. This is a number scale running from 10 (severe pain) to 0 (no pain).

We will also measure depression on a similar scale (scale: 4 - 0).

What statistical test should I use?


texts: What is the essential benefit of center-surround organization of retinal ganglion cells?

texts:
I am trying to understand the significance of the overlapping on-center off-surround and off-center on-surround organization of the retinal ganglion cells, also called center-surround organization. What is the advantage of such an organization from the point of view of vision?

To highlight the point of the question, wouldn't it be computationally and organizationally easier to simply have the retinal ganglion cells arranged in a non-overlapping fashion, and without the center-surround ability? Then there would be a straightforward correspondence between the incoming spots of light and the firing of adjacent neurons in the optic nerve.


texts: I saw this spider yesterday and it was the first time I saw one. It had a log slender body and an almost tail like end. It also can apparently jump. Just wanted to know what species this is. Location (Cavite, Philippines)


texts: Influence of temperature on protein binding and decay rates

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

Question

In particular, my question is:

How does temperature influences rate of protein binding to a DNA-binding motif?

I am NOT looking for..

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

I am looking for..

I am looking for a function (eventually expressing the michaelis-menten constant as a function of the temperature) that I can plug in my algorithms to incorporate the influence of various temperatures on the process I want to simulate. I want to simulate the average gene network from an average standard eukaryote. For other purpose, I chose parameter values coming from the yeast. A index such as the $Q_{10}$ would be very useful as well.

Similar already-answered question

A similar question (influence of temperature on transcription rate) has been asked and answered (by @rhill45) here.


texts: It is a behaviour that is very difficult to control. We can't sneeze with eyes open. Is it a reflex of brain to protect the eye from possible injury in sneezing motion or the neural pathway for sneezing is programmed to do so?


texts: Is there any biological basis for the emphasis on the value of the firstborn son?

texts:
Is the firstborn son biologically different in any way from the sons that follow?

Perhaps his epigenome is different? I have heard that a man's testosterone levels decrease when he becomes a father -- could this then have implications for the epigenetics of subsequent sons?


texts: Could someone clearly define what a gene variant is with an example. I am totally confusing myself with SNPs, alleles, variants and how the major and minor allele are defined. An example with gene names would be really helpful.


texts: Are the processes on afferent neurons that go from the sensory receptor to the cell body considered axons or dendrites?

texts: References on pain fibers say impulses move along axons to the CNS, but I thought that by definition axons carry impulses away from the cell body.


texts: Do B/T cells form from lymphoid tissue or bone marrow?

texts:
This website says lymphocytes are produced in bone marrow https://courses.washington.edu/conj/immune/lymphoid.htm

But if that's true, then what cells do lymphoid tissues produce? It could make sense if bone marrow is a lymphoid tissue, but red blood cells are also produced from bone marrow.


texts: What is the last heavy atom of an amino acid?

texts:
I'm a electrical engineer and I'm learning about bioinformatics. I was reading this paper that uses the last heavy atom to search for active sites of a protein but what would be a heavy atom? Is it all atoms but hydrogen? Atoms heavier than carbon? And how do I know which is the last heavy atom?

The article: http://bioinformatics.oxfordjournals.org/content/early/2014/11/08/bioinformatics.btu746.full.pdf+html

It talks about the last heavy atom under Materials and Methods 2.1.1 Individual Representation and Population Initialization


texts: I did an agar gel electrophoresis but I could not see DNA, why?

texts: After performing a PCR, I ran the products (700 bp) in an agar gel electrophoresis along with a Genedirex ladder (100 bp), but the transilluminator did not reveal them.


texts: We know that the genetic code is universal. My query is why the mitochondrial genetic code is different from universal genetic code?


texts: Can crocodilians differentiate their offsprings from other young crocodiles?

texts:
I read that some species of crocodilians can take care of their young for as long as a year.

How do parents differentiate their offsprings from other young crocodiles? Smell, appearance, sound?


texts: Is this question about limiting factors answerable?

texts:
This is from a Singapore-Cambridge GCE O-level Biology exam (a national exam for 16-year-olds). The exam board maintains that the question is "correct and accurate"—but isn't there a typo in option C?

Here's my argument:

Merely increasing the light intensity at either Points 1 or 2 speeds up photosynthesis, but varying the light intensity at Points 3 and 4 doesn't.
Therefore, light intensity is limiting photosynthesis at only Points 1 & 2.

At Point 3, merely doubling the $\ce{CO2}$ concentration speeds up photosynthesis; on the other hand, the graph shows no evidence that varying the $\ce{CO2}$ concentrations at Points 1, 2 or 4 speeds up photosynthesis.
Therefore, $\ce{CO2}$ concentration is limiting photosynthesis conclusively at only Point 3.

As this is a data-inference question, all the four answer choices are invalid deductions.
(Asserting that $\ce{CO2}$ concentration is a limiting factor at Point 4 requires assuming that raising $\ce{CO2}$ concentration beyond 0.08% continues speeding up photosynthesis.)
Excluding Point 4 from Option C will render this question finally answerable.


texts: Does the DNA stick to surfaces we touch?

texts: In case of robbery, the police visit the robbery scene and collect some samples like foot print or any item suspected to have been touched by the robber. The sample is then taken to laboratory for DNA analysis. Does that mean whatever we hold or touch, our DNA sticks or drops on it?


texts: Are there any multi-cellular organisms out there that do not sleep?

texts:
Looking around I see animals - ants, bees, birds, lizards, roaches all the way up to humans appear during a part of the day and not other parts. I would guess there is a sleep/recovery cycle involved.

Is there any multi-cellular organism with a nervous system, on record, that works without sleep/rest?


texts:
I am wondering about the logistics of a simple experiment with say 3 types of alcohols, and various concentrations of each, with a control(s)

I would like to research the effects of alcohol on mitosis. Do I need any expensive equipment or is it do-able with standard equipment? I am looking specifically at what I expect to be a negative impact on cell growth. Potential cell death and slowing of mitosis.

"We expect mitosis to slow and stop entirely or become corrupted as the amount of alcohol used increases. Of the three alcohols we will be testing, we expect some to be more damaging than others. The 3 chosen alcohols, listed in order of their hypothesised toxicity are Methanol, Ethanol and 2-methyl-2-butanol."

I am basically trying to see if tertiary alcohols are safer due to ethanols main metabolites acetaldehyde & acetic acid being more harmful/toxic? Since Tertiary alcohols for example, aren't metabolised into aldehydes. Which makes them less toxic than ethanol in theory.

Now I am unsure as to which cells to use to test upon, I'm also unsure as to the legitimacy of my hypothesis. Budget, time and a lack of knowledge is against me. I am researching as much as possible as quick as possible. Thankfully I have help available soon or I would be totally out my depth. This is me out of practice in the field trying to get a head start and help a friend out as best I can. I'll be his assistant and feel thats more than appropriate.

I realise I can't test for too many things. I need one clear goal. If we choose to test certain cells over others do you have any suggestions? and why?

The liver processes ethanol into acetaldehyde & acetic acid. So I would need these chemicals potentially in order to properly test ethanols effects on cells?

I am so out of my depth I feel right now I'm hoping for a prod in the right direction.

The 3 chosen alcohols, listed in order of their hypothesized toxicity are Methanol, Ethanol and 2-methyl-2-butanol. - concentrations of each yet to be considered.

I suffer from dyslexia and my wording is bad at the best of times. But please realize this is a very first draft / ideas on the table. Any help at all is appreciated, apologies for my lack of knowledge in the field. I'm trying to refresh my studies from 10 years ago in 2 days.


texts: Why is it always Sodium that we talk of in blood pressure?

texts:
Why is that we emphasize so much on sodium in blood pressure? I understand that it is a major extracellular ion, but, it also is tightly regulated. So when something is that tightly regulated, won't small concentrations of the potassium matter? And what about the chloride and bicarb? They are all there in the blood in comparable quantities but we never talk of their osmotic importance. Sodium retention and blood pressure - why not chloride retention?

Is it not required (like calculating sodium includes them too)?
or is it that they actually don't matter?
Also aldosterone, we conserve the sodium but aren't we pushing out potassium? Potassium also is an ion with oncotic activity right? Why is Natriuresis so important why not say, Chloriuresis?

So all in all, why does sodium steal the limelight?


texts: How do you determine the length of an annelid?

texts:
I'm currently studying a horse-leech, and would like to know if it is fully grown or not. When I read about different annelid species a maximum length is often given, so I wonder if there is some standard way of measuring these elastic animals?

For example, my leech varies from 2 to 10 cm, but often seems to prefer to stretch out to about 6 cm when not moving.

(Possibly I should modify this question to be just about leeches, but I also wonder about earthworms, and probably other soft and difficult worms as well...)


texts: Why don't sodium Voltage Gated Channels open during Repolarization?

texts: During Depolarization the Sodium VGC open when they receive the Threshold Stimulus. But when Repolarization occurs there comes a point when the cell interior has exactly the the same potential that it had during Depolarization i.e.,60mV but the Sodium VGC remain closed. Am I getting something wrong? If no, please explain.


texts: Is it safe to look indirectly at the Sun?

texts: I.e., is exposure of sunlight onto the peripheral vision less damaging than exposure onto the fovea?


texts: A single leaf in a very strange air current / wind?

texts:
Here is my eight years old movie where I have pictured a single leaf moving in a very weird way:

https://www.youtube.com/watch?v=sCjvgdfNCjU

Can someone explain me what is depicted in this movie (what process, event or situation) or otherwise what is causing this single leaf to move there and back in such way / pattern?

By listening to the sound or observing other leaves (barely moving) you can assume that this isn't a wind what is causing leaf to move. There was also nothing in the kind of spider web or no animal around that could influence leaf's movement.

The movie was captured in late September 2011 in southwest Poland, near Jedlina Zdrój in a forest on the hillsides of the "Mały Wołowiec" mountain (approx. 50°44'22.5"N 16°18'28.7"E).

Note: I understand that this question maybe considered a trivia, downvoted or even closed, yet it depicts one of my personal really weird biology-related mysteries, I ever run into. So, I'd really would like to know, what is going on here?


texts: TCGA gene expression data are missing matched normal

texts:
I'm trying to use the TCGA data portal to get gene expression data for cancer tissues, but I'm not sure what "Tumor matched normal" means.

It is unclear to me if the values are already compared to a control (non cancerous) tissue or there is another sample which gives the healthy tissue values. Assuming it is the latter, I don't see these samples anywhere.

This is a screenshot of my filter

http://www.clipular.com/c/5452873408184320.png?k=rlA9jy3Kb2U47JT7GrXBTzdsln4

And here is a picture of the result (only TNs appear).


texts: Does neuroeconomics study the brain or study economics?

texts:
I'm trying to understand what neuroeconomics is. There are two possibilities for what it might mean. (1) The study of cognitive processes in the brain by applying basic principles of economic theory like concepts of utility, decision making, etc. (2) The study of how a human behaves in an economic setting, somewhat like game theory and so on, which is more economics than brain science.

Which one is it?


texts:
Why do we feel emotions when we hear music?

Click to see video

How can a set of tones arranged in a specific order and timing make you feel sad or happy?

I read that music can somehow trigger the part of the brain which is responsible for language processing. Whatever be the mechanism of emotions, why do we feel that certain emotions are connected with certain tunes?

What may be the evolutionary origin of this?


texts: How much does calcium reduce iron absorption?

texts: Generally calcium inhibits the absorption of iron, but to what extent? One atom of calcium will not block 100% of iron absorption, that clearly isn't feasible. On the other hand, if someone ate 10 pounds of calcium, they wouldn't absorb any iron. How can we quantitatively determine the inhibition of iron absorption for a given calcium intake?


texts: How does one find the corresponding SNPs in the pair of chromonosmes in a FASTA file?

texts:
You might say I'm an amateur bioinformatician, or trying to become one.  I have a BAM file, from which I have succeeded, using UGENE , in extracting consensus data in FASTA format.  I now see a single series of nucleotides, and their complements, for each chromosome.  What I don't see is two corresponding sequences.  SNP data (e.g., SNPedia ) cites (if I understand it correctly) the SNP at the same site on each chromosome in the pair.  I don't know how to determine my variation, since I see only one nucleotide at any given site, not the pair.

Pretty sure I'm missing something fundamental here.  Thanks for any help navigating this jungle!


texts:
Do organisms exist that are able to live indefinitely if they are not killed by external factors?

Under external factors I would consider things like predators and natural disaster but not illness by bacteria for example.


texts: Can a rotten egg actually hatches to a real life?

texts:
First of all, I'm no expert in biology. I failed a lot in high school. Please bear with it if it's a stupid question.

For the past few days, I got a rotten smell as if an animal died in my kitchen. I cleaned and didn't find anything until I found the culprit today: leakage of rotten eggs.

There were two eggs in a hard plastic container, and one of them leaked a bit. Then I saw around 4-5 insects-kind of thing lurking around. It looks like a worm and if you ask me how those things look like, it's as if the egg yolk itself separated into the shape of worms and started moving. If I remember correctly, I believe I saw a pair of white dots (their eyes) in each.

Did those eggs (which was stored in a warm place) actually hatched and gave to a life? I threw all of them away, but I still feel really sick. Is it because of my carelessness that the egg yolk actually became alive in such shape?

Thanks beforehand.


texts: Has anyone tried to prepare chemically competent Mycobacteria?

texts: Bacterial species like E. coli are easy to transform using a variety of methods, including both chemical transformation and electroporation. Chemical transformation is especially nice to use as it can be done in high throughput. I'd like to start working with Mycobacterium smegmatis, though, and have only been able to find electroporation-based transformation methods like the one described here. Can chemically-competent mycobacteria be prepared? If so, are they just very inefficient? Is it worth testing some E. coli-specific methods with mycobacteria?


texts: Is there a specific name to the head motion some baby cattle makes when nursing?

texts:
Unlike human beings, cow's head doesn't remain stationary while nursing. Refer to the following video for reference:
https://www.youtube.com/watch?v=xDK9s8n6AAk
This is not the case with horses, refer to this video: https://www.youtube.com/watch?v=Q3lKl4FXuCI
But again, goat show the same behavior: https://www.youtube.com/watch?v=Q5JkgXFRHHs
Is there a biology-related word for this?


texts:
I just found what i think is an insect on floor of my balcony. From what i know, it is a Praying mantis. I want to keep it as a pet but for that i want to its exact species.

If it helps:
 Location: Bangalore, India
Temperature : $23^{\circ}$ C

Could someone help me identify it pleas.


texts: How to determine if a plant is autotrophic or heterotrophic?

texts:
How do you determine if a plant is autotrophic or heterotrophic, and are there any traits in particular that can be used to classify species?

As two examples, how should Melampyrum pratense and Orobanche be classified?


texts: What kind of fish is this (Florida, USA)?

texts: What kind of fish is this? It was caught in Florida (USA) in a canal and was in a group. It was about 5 or 6 inches in size.


texts: The size of the Triceratops specimen Lane in the Houston Museum of Natural Science

texts:
In 2012 the Houston Museum of Natural Science published they discovered an almost complete fossil of Triceratops including fossilized skin, see HMNS post, and nicknamed it "Lane".

I am interested to know the size of the Triceratops specimen Lane and in particular: total body length (TBL), total head length including the frill (THL) and brow (superorbital) horns cores length. Estimation of weight would also be great but I doubt if there are any.


texts: What are the differences between mammal and insect digestion of cellulose?

texts:
I know that digestion of cellulose is difficult in mammals and requires a lot of steps. But I am fascinated by the idea of one day achieving human digestion of cellulose.

Which got me thinking about how insects digest cellulose much faster than mammals, how is this possible?


texts: Do human beings have pheromone receptors?

texts:
What is the current consensus on whether or not humans have receptors that detect pheromones?

If there are purported receptors, in what anatomical areas are they located?  With what organ systems do they interact?


texts: During the process of plasmid isolation, how can we be sure that only plasmid DNA has been isolated and there is no chromosomal DNA?

texts: We separate the membrane and all other cell components, but how is it that only plasmid DNA is isolated and not chromosomal DNA?


texts: Evolution, self organization and neuroscience

texts:
I have rudimentary knowledge of evolution, and biology in general, so bear with me if this question is a bit naive.

Let's say we have a particular trait, like highly sensitive peripheral vision. There are two ways to go about explaining how this came about:

One is to say that evolution selected for it over time, because animals with a poor sensitivity to peripheral activity could easily become prey. So there is an advantage to having sensitive peripheral vision, and such a trait is adaptive. The picture I have in my mind is of an assembly line where there are randomly wired visual cortices and the best ones get selected for automatically. This seems to be the view of the field of evolutionary algorithms, at least to my mind.

Now, if we focus on the random nature of the wiring, we might see that there is an explosion of possibilities in terms of how the visual system can be wired together. After all, evolution is blind, and it doesn't know beforehand which physical signals are of interest.

I'm trying to think of a more plausible mechanistic explanation. Suppose we assume that given certain reliable properties of the physical world, like permanence of objects for example, evolution has found the optimal way to wire the visual cortex so that peripheral vision (and a host of other good-to-have features) is a natural outcome, then it would give us more focus in what environmental features and algorithms to look for. This can also be thought of as the idea that evolution, over time, has come to assume that certain things in the physical world will be a given and exploits these. (For example, objects in the peripheral areas of vision will tend to have different perceived velocities, so perhaps normalizing velocities across the field of vision automatically results in a need for higher sensitivity in that region. It just so happens that this could also be useful in detecting predators).

My question then is, is my assumption in the above paragraph valid? (Of course, the question then gets shifted to "Why normalize velocities across the visual field in the first place?").


texts:
There are many definitions of "species" which usually take the form

Two individuals are of the same species if ...

An implied (rarely made explicit) property of any sensible species definition is that the relation "is the same species as" should be an equivalence relation (the reason why this is sensible is that only such a relation partitions the set of all individuals into equivalence classes, that is, separate species). In particular, it should be transitive, that is

If A and B are of the same species, and B and C are of the same
species, then it follows that A and C are also of the same species.

It appears to me that all species definitions in use violate that property.

Example
Are the Chihuahua  and the Great Dane  of the same species?
Not according to the "biological" species definition, which states:

Two individuals are of the same species if and only if they can produce fertile offspring.

Since that is (presumably) not true of Chihuahua and Great Dane, according to that definition, the two dog breeds are not of the same species.
However...
Let us say that the Chihuahua can produce fertile offspring with the Dachshund...

... and the Dachshund with the Golden Retriever...

... and that at last with the Great Dane as desired.
Then, if we assume transitivity, Chihuahua and Great Dane are of the same species - contradiction!

Another Example
Are the Chimpanzee  and the White Oak  of the same species?
Intuitively, they are of course not, the very idea seems ridiculous. Sure enough, with the definition (a variation of the "genetic" species definition)

Two individuals are of the same species if and only if their genome differs in less than 0.5% of base pairs.

the two are indeed not of the same species.
However, we can again construct a "chain" of intermediate individuals, each of which is similar enough to its predecessor to satisfy the definition, eventually connecting Ape and Tree and violating transitivity again.

My question to biologists: How is this problem resolved in practice? Are there any species definitions that preserve transitivity?


texts: Why is polyploidy much more common in plants than in animals?

texts: There are very few animals with polyploidy like salamanders. Why is it that polyploidy is so uncommon in animals? On the other hand there are numerous examples of polyploid plants. If ut something to do with the gene dosage, how does it not affect plants?


texts: Lac operon: How can lactose enter the cell in the absence of lactose permease?

texts:
My textbook states that

  lactose permease...transports lactose into the cell

and

  When lactose is added to the growth medium, the lactose molecules bind to the other site on the repressor protein

My question is, how can lactose enter the cell to bind to the repressor protein to allow beta galactosidase and lactose permease to be synthesised if there is no lactose permease present to transport the lactose into the cell?


texts: Can the Na+/K+ pump backwards to generate ATP?

texts: The standard physiological direction of the Na+/K+ pump is to export 3 Na+, import 2 K+, and hydrolyze one ATP to ADP. Can it be driven backwards, importing 3 Na+, exporting 2 K+, and generating ATP? Does this happen in normal cells, and in what conditions?


texts: Does muscle get bigger by increase in size of individual cells or increase in number?

texts:
Somewhere in the back of my mind, I have the claim that a muscle never increases its amount of cells but, if the muscle gets bigger, it's simply because individual cells get bigger.

The book Anatomy Trains on page 36 cites "Changes in sarcomere length and physiological properties in immobilized muscle by  Williams et al" when it makes the claim :

  Stretched, a muscle will attempt to recoil back to its
  resting length before giving up and adding more cells
  and sarcomeres to bridge the gap.

Is that true? Do muscles increase the number of their cells in that way?


texts: What are the white dots on the tree in this photo?

texts:
Today in Kongens Have, I noticed a lot of white dots on bark of trees. There are plenty of them, and they were usually on 'bottom' side of branches. Does anyone know what this could be?

I took a photo:

I suspect some pupa of insects, but it is just a quess.


texts: Protein modification and ATP consumption

texts:
According to wikipedia there exists a lot of ways to modify a protein (post-translationally). Just to mention few: phosphorylation, dephosphorylation, glycosylation... While phosphorylation requires an ATP molecule, the reverse reaction, dephosphorylation, does not.

How about the other process?

Do all modification respect this scheme (i.e. one transformation consumes ATP but the reverse transformation does not)?

If not, I am particularly interested to know if one transformation and its reverse transformation both requires ATP.

Thank you


texts: Meaning of proliferation rate of 3 day−1

texts:
The abstract of an article in Journal of Virology contains the following line:

  We find that CD8+ cell proliferation begins 1 to 2 days after infection and occurs at an average rate of 3 day−1, reaching the maximum population size between days 5 and 6 after immunization.

What does this figure mean? Does it mean that per day the population after proliferation is 3 times the original population?


texts:
I've looked all around online for an answer to this. Some sites say menthol causes blood vessels in the nose to constrict, some sites say it causes blood vessels to expand. Many sites simply say it's a remedy, but with no explanation.

And if it does cause the constriction or expansion of blood vessels, what's that got to do with making the stuffiness go away?


texts: My question is out of curiosity and got me thinking. How did viruses with the head, tail and tail fibres actually evolve? These viruses look more like machines than biological entities. Are there any theories to how these viruses evolved?


texts: What causes tissues manifest the various forms that they do?

texts:
A heart (or any other organ) is comprised of a group of cells. To the best of my knowledge, the growth of a heart depends on cell division. However, cell division by itself doesn't seem to explain why heart cells collectively manifest the form of a heart.

What causes tissues to manifest the various forms that they do?


texts: Can we influence evolution by teaching primates to control fire? Should we?

texts:
Most people with a strong interest in biology will have heard of Kanzi the Bonobo, the ape that has the wherewithal to collect fuel for a campfire and play pac-man.

But is it conceivable to influence the course of their evolution so that it becomes more likely they gain the intelligence to support a civilization in the distant future?

Let's face it: it's easy to imagine that Bonobos are looking superficially like early human ancestors.  They have been forced to become more peaceable and social because they are polyamourous (which is why the human phallus is shaped the way it is).

If we are willing to genetically modify them, we would have to do so so heavily the depend on the genetic modifications, or they might just get bred out again - intelligence may be delicate.

In conclusion, is it conceivable to "enlighten" some groups of primates and send them into the wild, in the hopes they (much) later evolve intelligence?  Their existence would serve as an "insurance policy" on intelligent life in the not unlikely event we destroy ourselves.


texts: What can cause a lump in the middle of the neck? (homework case study)

texts:
What can cause an erythematous, fluctuant, nontender mass in the middle of the neck?

Full Case Study: (Its the last of 6 cases and I just can't figure this one out,  because of all the possibilities, there is always something that doesn't line up.)

The 26-year-old man presented for evaluation of a neck mass and a right axillary mass. The patient, who came to the United States from Vietnam 6 1/2 years ago, noted  midline neck mass. The mass gradually increased in size. Approximately 3 weeks prior to admission, he noted a midline neck mass. These masses were incised and drained twice. Samples of purulent material were sent for routine bacterial culture at an outside hospital. The patient had lost 3 kg (ca. 7 lbs) in the 2 months prior to admission but denied fever. Travel history was notable for his having lived in Arizona for 6 years prior to moving to Boston.

On examination, he was afebrile. An erythematous , fluctuant, nontender mass (8cm x 6cm) was present in the midline of the neck. (Fig. 5.1)  (computed tomogram[CT] scan in fig. 5.2).The right axilla demonstrated incision sites that were draining and were tender to palpation. He had no adenopathy elsewhere. His (PPD) purified protein derivative skin test was reactive, and his chest x-ray was notable for apical scarring in the right lung.

Because of the positive PPD and apical scarring seen on the patient's chest x-ray, the clinical suspicion of cervical ________ was high, and the patient was begun on a four drug anti- _________________ regimen.

Several days after the neck mass was drained of several milliliters of purulent material for culture, a mold was found to grow on the blood agar plates in the routine bacteriology section of the microbiology laboratory. The mold was white (Fig. 5.3) and initially did not have any identifying characteristics when a lactophenol cotton blue preparation was examined under a phase-contrast microscope. It was subcultured at both room temperature and body temperature, and after subculture began to demonstrate the presence of  spores microscopically (Fig. 5.4) The identification was confirmed by using a commercially available genetic probe.


texts: I am having trouble differentiating onset/offset of muscle activation. Is there anyone in the field has a specific way to set the threshold for both time and magnitude?


texts: educational sources for learning biochemistry

texts: I just finished high school and am going into a biology undergraduate degree, I'm getting into biochemistry too and would like to learn more about it through online platforms or even non-fiction books to use my time effectively this summer. So far I've been using online flash cards to learn more about the jargon and would like to hear some suggestions of platforms or books to read that teach concepts strongly tied to biochemistry beyond what a basic high school curriculum would teach.


texts: Why are the retina layers arranged the way they are?

texts: The retina layers are arranged in such a way that light has to pass through several layers before hitting the photosensitive cells. Won't this be much better if the photosensitive cells made up the first layer? This way there would be no blind spot.


texts: Is there a dominant gene for right-handedness?

texts: Has there been any definitive research about handedness being genetic? Also, why is right-handedness clearly dominant in humans? I'm interested in evolutionary theories, as well as any molecular explanation (if known).


texts: Is there any way to design a PCR primer if region of interest is highly repetitive (tens of kilobases only SINE's & LINE's)?


texts: I am unable to understand what happens to the phosphates from  ATP. What are they used for ?Charging 3' end or 5'end ?


texts: How much myrosinase do mustard sprouts contain?

texts: It is known that ground mustard seeds contain active myrosinase, but what about soaked or sprouted mustard seeds?


texts: Where can I find hemagglutination inhibition (HI) assay data?

texts:
I am looking for hemagglutination inhibition assay data for type A influenza virus. I've checked in databases such as fludb.com, however it seems to only have genetic data. A lot of the time, scientific papers don't include the HI assay data they used, so I was wondering if anyone knows where to find such data. I specifically need influenza type A HI assays, not influenza type B.

HI data comes in the form of titers (the reciprocal of the last well plate concentration of antibody that was able to inhibit the virus from binding to the blood sample and forming a shield on the well plate.)

Could someone please give me a link to a database with this information?

Thanks.


texts:
We are currently doing an screening where supernatans from a bacteria genus are tested againts a pathogenic bacteria cell culture in a 96-well plate where OD is measured each 2 hours.

Each supernatant from a strain has 3  replicates  and the control phatogenic bacteria cell culture has about 11 replicates inside the plate.

Once each experiment is finished cell growth curves are modelated and 3 growth parameters are determined (mu, lambda and max absorbance) from each supernatant tested and from the control. Then a Mann-withney U test is performed for each growth parameter from each strain againts corresponding control parameter to check if there's some kind of possible inhibition.

The strains which has some inhibition efect againts this pathogenic bacteria will be tested again in further experiments to confirm the possible positive.

I  have a doubt about if performing statistical test to compare supernatants from each plate againts its corresponding control is correct considering that the possible candidates will be again tested in further experiments to confirm its inhibition. Since there's loads of strains to test, repeating each single experiment more than 3 times would take too long.

What it is your oipinion? Is it correct to do statistics for single plate (technical replicates) to gather possible positive for a later confirmation (biological replicates)?

Thank you

Are biological replicates strictly needed in this case?


texts: How do mosquitoes react to blood feeding on a highly ethanol intoxicated host?

texts:
Considering that a mosquito can consume up to five times its body weight in blood during a single meal (Encyclopedia of the Arctic, M.Nuttal), and considering a very strong alcoholic intoxication of about 3g of ethanol /l of blood, what could be the effect on the mosquito of such a "binge blood feeding" ?

Blood with a 3g/l ethanol concentration corresponds to a a beverage with 3/789 (ethanol density) = 0.38 % of alcohol.

Brought to a human level, it is as if a 80 kg man would drink 400 kg of blood, which would have a volume of 400/1.06 (human blood density) so 377 L. Within these 377 L, 1.43 L is pure alcohol. Weight of that alcohol would be 1.13 Kg.

In mammals, blood weight represents about 1/13 of the total body weight, therefore in our example for a 80 kg man about 6.15 kg, hence 5.8 L.

So since alcohol is readily absorbed through the gastrointestinal wall, this would quite quickly lead, based on the "unfed" weight, to about 195 g of ethanol / L of blood. Ethanol lethal dose in human is commonly reported to range between 8 and 14 g / L. So with that dose you're dead about 15 times.

So I am perfectly aware that I am asking about mosquito and not humans, and that i am not taking into account several other parameters, but the demonstration was just displayed to prevent answers like "naaaaah no way dilution is way too high", so please elaborate your answers and comments and don't hesitate to provide references.

On another level those comments would be useful to clarify many animal models used on studying vector borne diseases involving the blood feeding of the vector on anesthetized animals.


texts: Action potential attenuation in unmyelinated axons vs demyelinated axons

texts: I learnt that action potentials travel much faster along myelinated axons, and when these axons are demyelinated the action potentials travel much slower and sometimes die out. Why do action potentials die midway in unmyelinated axons?


texts: If a given DNA oligo is an aptamer, will the corresponding RNA oligo with the same sequence be an aptamer aswell?

texts: Functionality of aptamers depends upon the oligo's sequence and secondary structure. So, if I take a DNA aptamer and make an RNA oligo of the same sequence (T replaced with U obviously), will this RNA oligo also act as an aptamer?


texts: What kind of red and black insect is in the photo?

texts:
I was wondering what kind of insect this was that I found on a flower on my deck this morning?

The insect was in my flower pot on my deck. I took the picture from my cell phone and zoomed in for a clearer shot. The body of the insect (not counting the antennae) was about an inch.


texts: phylogenetic Independent contrasts with unresolved tree

texts:
I have a dataset containing morphological and performance measures of species from various groups, including insects, lizards, frogs, spiders etc, and want to analyse the relationship between these measures and the animal's body size  via regression methods, while controlling for common ancestry, similar to what has been done in this work:

Peattie, A. M. & Full, R. J. Phylogenetic analysis of the scaling of wet and dry biological fibrillar adhesives PNAS, 2007, 104, 18595-18600

http://www.pnas.org/content/104/47/18595.abstract

For most of my species, statistically supported branch lengths are lacking, and I was thus wondering what the best way to conduct my analysis would be, and I would be grateful for any hint.


texts: What is most ancestral: isogamy or anisogamy?

texts:
Sexual reproduction can be feasible with anisogamy (gametes of different sizes i.e. genders) or isogamy (gametes of same size i.e. mating types) or with undifferentiated gametes (i.e. true random mating; although I have to confess that I am not aware of such example).

De novo evolution of sexual reproduction happened several times independently. What seem to be the most ancestral states of gamete differentiation (isogamy or anisogamy)?. Does it differ between lineages?


texts: Why are canines not nauseated by similar foodstuffs/state of decay as human beings?

texts:
I am continually surprised at the items my pet dog is willing to ingest.

I understand part of the consumption is driven by nutritional instincts (licking salty liquids such as sweat) or nurturing instincts (eating baby faeces to prevent predators) but why does an animal with a sense of smell many thousands of times greater than our own not become nauseated by the same substances, smells or conditions that humans do?

Sweat
Faeces
Decayed foodstuffs
Assorted garbage
Untreated and/or dirty water

I have known my dog to bury a piece of rotting pork only to dig it up several months later for consumption.

In addition I watched dogs refuse to eat certain items (spicy meat etc) until their owner makes a move to take it back at which point the animal will swallow the item causing a gag, hacking couch or nasal clearance.

Is there a biological mechanism that suppresses the gag reflex in canines, is the need to consume overpowering their distaste or do they simply not find such substances unpalatable?


texts: Understanding David Chalmers claims on direct mappings between our vision and visual awareness systems

texts:
I am reading the popular 1995 paper "Facing Up to the Problem of Consciousness" by David Chalmers [PDF] as part of my philosophy course. I am only asking about the relevant vision related claims Chalmers makes, so you need not read the full paper.
In the section 7.1 (emphasis my own):

The properties of this [complex three-dimensional] space can be recovered from information-processing considerations:
examination of the visual systems shows that waveforms of light are discriminated and
analyzed along three different axes, and it is this three-dimensional information that is
relevant to later processing. The three-dimensional structure of phenomenal color space
therefore corresponds directly to the three dimensional structure of visual awareness.
This is precisely what we would expect. After all, every color distinction corresponds to
some reportable information, and therefore to a distinction that is represented in the structure
of processing.
In a more straightforward way, the geometric structure of the visual field is directly
reflected in a structure that can be recovered from visual processing.

"Awareness" is defined (earlier in the same section) as:

...the contents of awareness are to be understood as those information contents that are accessible to central
systems, and brought to bear in a widespread way in the control of behavior. ... Awareness is a purely functional notion,..

So, I believe visual awareness refers to "how visual signals are processed in the brain".
Chalmers gives vision only for example, as he states that "It is also a central fact that to each of these structural features, there is a corresponding feature in the information-processing structure of awareness." - that is - he generalizes these to all perceptions. However, we can restrict our question to vision for now.
Note the phrases I have emphasized in bold. From what I understand, Chalmers is claiming:

direct correspondence, in that 3D structures in real world ("three-dimensional structure of phenomenal color space") form 3D structures in our brain ("three dimensional structure of visual awareness").
the "geometric structure of the visual field" is directly reflected inside our brain in some structure, so that the original geometry can be recovered from this structure.

I wish to ask for biological justification/backing of these claims.
From what I understand, our two eyes receive 2D data, and our brain combines these (slightly offset) 2D images to produce 3D (depth) sensing. Our perceptional ability is severely limited, and it is only because of a lot of "postprocessing" done by the brain that we form our perceptions. This is also the reason why we often perceive motion in changing static images (animation) or are confused by optical illusions (for example, perceing 3d from 2d images on paper, and many more).
My points are similar to the ones raised by Torbjörn Skytt in their paper "The "hard problem" of consciousness is a dead end" (link).
I am not arguing against the claims. But, I am unable to reconcile these claims ("direct reflection" and "direct correspondence") with the day-to-day observations outlined above. Moreover, Chalmers claims that these are "central fact"s, however, I do not find them to be so obvious. If I can get some clear perspective/stand on these claims, it would be helpful.


texts: How does the mechanism which controls blood pressure in the brain work?

texts:
I know that pressure is sensed in the skin by mechanoreception mediated by skin receptors. Static pressure stimuli are mainly sensed by slow-adapting fibers connected to receptors like the Merkel discs. Vibratory stimuli are sensed by rapidly adapting receptors like the Pacinian corpuscle.

Blood pressure is also sensed by the body and the brain regulates blood pressure by influencing the peripheral nervous system that can increase or decrease the blood output of the heart.

How are blood pressure differences in the brain sensed and how do these receptors mediate cardiac activity? Are blood pressure differences in the brain sensed by rapidly adapting receptors akin to Pacinian corpuscles?


texts: What is the point of toxins without remarkable coloring?

texts:
As far as I know, some toxic species (eg: some mushrooms) have no remarkable coloring. Therefore, what is the purpose of their toxins?

Toxic species often have colorful appearances to warn predators. Therefore, if a species has toxins but no vibrant coloring, this seems to me to not be beneficial for either this species or potential predators. But still, some toxic mushrooms (for example) have plain coloring.
What is the point of being toxic without vibrant coloring?