texts: Mitochondria - are they really separate organisms that once merged into eukaryotic cells?

texts:
Theoretically, mitochondria are said to be a separate organism that is concerned with its own life and its own processes. In fact, it even duplicates individually. I know a similar question is here but I have something else apart from that to ask.

Is the presence of their own DNA/RNA - like compound justify or prove that the mitochondria was once a separate living organism?
If the mitochondria is indeed a separate living organism, then how is it controlled by the nucleus? Or is it not? Logic would suggest that since mRNA exists in the mitochondria separate from DNA in the nucleus, they have their own control over how they behave.
Often, living organisms working together have to have some sort of payment system. For example, bacteria in the body provide Vitamin K and other breakdown vitamins, and in return the body gives it a suitable home to live in. Is there any such business occurring between the individual cell and the mitochondria? Does it keep some nutrients for itself? If not, what is its mode of nutrition?
In effect, cells did exist before mitochondria joined the party. Is there any way to at least have a feasible hypothesis on why and how the cells bonded with the mitochondria or how the cells even existed in the first place without the presence of and organnelle that can break down food and convert it into energy?
Why do mitochondria have their own membrane? And that too folded? Is that to increase the surface area available for the electron transport chain, or is it for simple compactness?
Why does the mRNA in our bodies always exactly match the mRNA of our mothers and only our mothers? Can any genetic mutation change this fact?
Is it possible, that a mitochondrion can somehow escape the cell and start performing its life otherwise?
mRNA would suggest that mitochondria make their own proteins / at least some basic amino acids. If there are any such proteins, are they utilized for the cell? Or are they used for cellular respiration? Or are they kept by the mitochondria for there own means?

I will appreciate all answers!,
SmallDeveloper (a.k.a SmallScientist :) )

EDIT : Basically, I am asking 3 things:

Were mitochondria really separate organisms once?
If so, how do they get their nutrition?
How did cells exist before mitochondria came along?


texts: Why don't we have more cone cells (bigger fovea)?

texts:
Background

Apart from being able to sense color, cone cells are able to perceive finer detail and more rapid changes in images, because their response times to stimuli are faster than those of rods.

The fovea centralis is where cone cells are most concentrated and is responsible for sharp central vision (foveal vision), which is necessary in humans for reading, driving, and any activity where visual detail is of primary importance.

Question

It is hard to imagine what it would be like to be missing the fovea centralis, and even harder to imagine what it would be like to have one the size of the entire retina! In any case it seems that having a bigger fovea centralis would be beneficial for survival, so why do we have so much peripheral vision?


texts:
How many human cells are there in our body, on average?

Wikipedia says 1013:

  Bacterial cells are much smaller than human cells, and there are at least ten times as many bacteria as human cells in the body (approximately 1014 versus 1013).

The Nobel site says 1014:

  An adult human being has approximately 100 000 billion cells, all originating from a single cell, the fertilized egg cell.

The Physics fact book insists it's 1013:

  (length of 1 bp)(number of bp per cell)(number of cells in the body)
  (0.34 × 10-9 m)(6 × 109)(1013)

Finally, Wolfram Alpha gives 1.0 × 1014 as fact:

  Estimated number of eukaryotic (human) cells in the human body: 1.0×1014

I am quite confused: who is right here?


texts: What is this lightning-fast tiny spider?

texts:
Saw this spider as I was taking a shower. It moves really fast. This I noticed when it moved away (from the center of this splendid pattern) to repair its web.
Location: West Bengal, India.
It appears to be almost 1.5 cm in length.


texts: I have an undirected network and I am currently analyzing both three and 4 node motifs in the network. However, I can't find any articles which describe the biological significance of 3 of 4 node motifs in my network. Comparing with randomly generated networks, I am able to deduce that the number of three node motifs and 4 node motifs are significantly higher. However, I am unable to infer any biological significance for this finding.


texts: Anopheles arabiensis lifespan and sporogony duration

texts:
What is the longest observed lifespan of a mosquito, especially of the species Anopheles arabiensis? How long does it take for Plasmodium parasites to develop and move into the salivary glands of these mosquitoes?

I need this information to calibrate my model on malaria transmission.


texts: Biological Neural Network Modification to Unlearn Understandings

texts:
Lets assume that a person grows up thinking that religion X is true religion. So he builds up a profile in ones head and when notion of religion X appears the neurons that is related are fired, giving sensation of God and related stuff.
Lets us also assume that later in life he learns that religion X was not correct, then does "realization" of this fact happens by modifying old neural networks or a new profile is created for religion X and old profile gets deleted?
In other words do neurons associated with sensation that religion X was true religion "modified" or a new network is created giving a new sensation that religion X was not true religion along!
In my general understanding modification of old network could be challenging assuming that they are surrounded by other neurons associated with other stuff, a certain modification by having more or less neurons would result in borrowing neighboring neurons and wiring them to create a modification or loosing some connections to create a modification, which doesn't seem efficient.

I am not sure how is this question "opinion based"? I have asked a concrete question with a general example.


texts:
On the wikipedia page about crocodiles crocodiles are called true crocodiles. Does this mean there are (or where) false crocodiles as well?

  Crocodiles (subfamily Crocodylinae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. Crocodylinae, all of whose members are considered true crocodiles, is classified as a biological subfamily.https://en.wikipedia.org/wiki/Crocodile

The only "false crocodile" I found was the False gharial.

What is a false crocodile? if it exists at all. If not what is the reasoning behind the naming of a true crocodile?


texts:
How would you define Regime of selection (or Selection regime)?

In addition to a accurate definition, a developped example would be very welcome!


texts: Species identification; clusters of big plump red bugs in Taipei

texts:
I saw these red insects in Taipei near XinBeitou MRT station in the last week of April 2017, around lunch time. They were fairly active and would keep checking each other out with their antennae for a moment and then move on to the next. What struck me was the wide range of sizes and development in the groups. I didn't notice any feeding or mating that I could recognize, just a lot of walking around and checking each other out.

There are plenty of birds around (this is quite a green area) but I didn't notice any interest by birds in eating them.

I've also included a screenshot from google maps so you can see the location and the trees growing in these concrete structures.

The body of the largest individual is probably 2.5 centimeters long.


texts: Explaining a branch with visibly different leaves on Citrus japonica

texts:
My father was so kind as to send me a tree of Citrus japonica, aka Fortunella japonica aka kumquat (all names mean the same according to Wikipedia). Though I have seen this species many times, it is only now that I noticed two very distinct kinds of leaves.

One kind of leaves that I call  'double leaf' (second image) is only found on one single branch. The branch is still green down to where it merges with the tree, but many of the leaves are among the biggest on the tree. Excepting one sickly not fully formed leaf, all leaves on this branch seem to be of this 'double' type. I checked carefully.

All other leaves are of the kind shown in the first image.

This is the tree as a whole:

How can this different type of leaves on just one branch be understood? Does that branch belong to a different kind of Citrus (meaning grafting occurred), or is this a stage in leaf development? I don't think the latter, because I found small single leaves in the top branches of the tree. But I also don't think the former, because father said no such thing. If it is a mutation, why does it solely affect one branch?

I am a particularly ignorant amateur, but if you instruct me what to observe or photograph, I shall gladly do so.

Edit:

I thought I should supply a picture of where the unique branch emerges from the tree:

The tree bears fruit and at its thickest point is marginally thinner than my thumb.

Edit:

It just occurred to me that the entire upper kumquat might be grafted onto a different kind of citrus, which would explain such behaviour in the lower branch. I will search for evidence of this in the morning.


texts: About. Autosomal recessive diseases in genetics

texts: What happens if homozygous dominant  alleles are present in an individual for an autosomal recessive disease will he be affected ?


texts: Can a constitutively active kinase be highly regulated?

texts:
I am studying the protein kinase GSK3 and I am learning about the regulation of its activity. Many journal papers that I have read have stated that GSK3 is unique because it is a constitutively active kinase, meaning that it is always active and is not activated in response to a specific stimulus/condition. I have read that phosphorylation of GSK3 at specific tyrosine residues only enhances its activity, but the GSK3 itself is always active.
However, many of these papers also talk about the various mechanisms through which the activity of GSK3 is regulated (e.g. through phosphorylation at specific amino acid residues, subcellular localisation, protein complex formation). One paper states the following:

The many functions regulated by GSK3 (through its phosphorylation of
numerous substrates) suggests that the activity of GSK3 must be highly
regulated. Four key mechanisms have been identified that contribute to
regulating the actions of GSK3 in a substrate-specific manner. These include regulation by phosphorylation of GSK3 itself, the subcellular localization of GSK3, the formation of protein complexes containing GSK3, and the phosphorylation state of GSK3 substrates.

I am wondering how is it possible for a kinase to be constitutively active and be highly regulated at the same time? If it is constitutively active, doesn't this imply that it is always active? Any insights are appreciated.


texts: Pathogenesis of type IV hypersensitivity

texts:
In hypersensitivity, as I understand it, a normal immune response gets excessive, misdirected or wrongly regulated to cause tissue injury. The various types determine the various ways in which the tissue-causing responses are effected, at all times the ultimate cause being either excessive response (the normal amount being harmless), misdirection or wrong reglation. Hence, the ultimate cause beneath all hypersensitivities is some factor which just unleashes the immune machinery on normal tissues.
With this in mind, as Type IV Hypersensitivity is typically described under the headings of a granulomatous reaction, DTH (Delayed type hypersensitivity) or a contact dermatitis type response, involves the stimulation of $T_{h1}$ and $T_{h17}$ subsets of $T$ cells (along with $\text{CD8+}$ cells). What I fail to understand is that,
What goes wrong along the normal T-cell effector pathway to ultimately cause the injury?
(In type I, it is the IgE arsenal release on parasite mimicking allergen, in type II it is the self-antigen directed or hapten mediated self-tissue direction of Ab, and in type III it is the precipitation of immune complexes owing to the overburdening of the Ag-Ab response due to continued influx of Ag which cause the problem)
The events of stimulation, cytokine release and macrophage proliferation and activation is exactly what you would expect to be, in case the cells are doing what we want them to, to ward off a normal invader. But it ends up damaging the tissues.
Moreover, a lot of books say some variant of

"DTH is necessary to fight some specific pathogens"

Since hypersensitivity, (and hence DTH) by definition is immune-mediated tissue injury, do they mean that this tissue injury is indispensable in the fight against these pathogens (in which case, is worrying about DTH necessary?) or that the normal unaltered form of the pathway of immune response (the altered form of which results in DTH) is necessary for the fight (in which case there is a minor semantic error in the quoted statement)?


texts: How can a tongue-biting parasitic arthropod become a fully functional tongue?

texts:
From wikipedia:

  The parasite Cymothoa exigua [consumes a fish's tongue and] then replaces [it] by attaching its own body to the muscles of the tongue stub. The fish is able to use the parasite just like a normal tongue.

Wikipedia says that it replaces the host's tongue and becomes fully functional. But how does the arthropodic parasite reattach the nerves of the fish, such that the fish can assume control of it? Am I misunderstanding something?


texts:
In the section describing the Calvin Cycle, under the subheading "Reduction",  my textbook states that:

  The steps involve utilisation of 2 molecules of ATP for Phosphorylation...

I could not get where is ATP used in Phosphorylation (ATP synthesis by cells)? Please help me to understand.


texts: Why don't we see turbulence in the aorta even in normal situations?

texts: I read about the Windkessel effect. Then I read about pulse pressure waves getting reflected from the periphery. If the pulse pressure wave is reflected during diastole and at the same time blood is being pumped forward by the aorta due to the Windkessel effect, then we have two opposite forces acting which should create turbulence even in a normal aorta. Why doesn't this happen?


texts: Please identify this bone found on the beach

texts: I've found it on the beach in Çanakkale, Turkey. Width 7.5 cm, height 5 cm. Inner hole dimensions are 2.5 cm x 3 cm.


texts: Could someone entirely absorb smells by smelling?

texts:
When smelling, your nose detects the smells by absorbing them.

Does this mean that, if you were in an enclosed space, you could smell so much all the smell goes, and there is none of that molecule left to smell?

Would it take so long it would never happen in reality, or does it happen?


texts: What kinds of arousal can a human brain experience?

texts:
I've been reading about the new phenomenon called "arousal addiction". The context in which this term is used is Internet, Porn and/or video game addiction(cummulatively Internet Addiction Disorder - IAD). Dopamine and Dopamine receptor D2 are sometimes mentioned, as being affected by exposure to a new, novel stimuli.

I'm interested if there are other forms of "arousal" that may involve more than just Dopamine. For example, I know that there are 4 neuromodulators in the human brain:

Dopamine
Serotonin
Choline
Noradrenaline

For example, if a person likes horror movies to the point of addiction, is it Dopamine, or is it Noradrenaline that the person enjoys? If a person is addicted to comfort foods, is it Dopamine or Serotonin?

Thank you!


texts: Can the characteristics of an offspring depend on the locality of its conception also?

texts: Transfer of characteristics from a parent to its offspring is explained in biology. When an adult male and female (of humans) who are displaced from their local environment to another (say, a different continent)for a considerable period of time, conceive and give birth to a baby, the newborn also shows some traits related to the people of the new locality . How is this explained?


texts: I wonder if there is any connection between exhaled air and lung capacity. I need to implement some algorithm in my game to calculate points of how much time you blow and compare it maybe with some sportsman.


texts: Why Can't The Immune Systems of Uncontacted Tribes Handle Our Common Colds?

texts:
I'm sorry if this is a stupid question, I'm just starting my first year of a biomedicine degree and I'm curious - googling didn't find me any answers.

I know that the Aboriginal Australians and many other native peoples have been wiped out by diseases such as smallpox, influenza, the common cold, and malaria. A lack of immunity to our diseases is currently an ethical concern of contacting previously uncontacted tribes.

Seeing as we can't properly develop full immunity to the common cold - as it's always changing - but we manage to always fight it off, and (I think) our immune systems are all fundamentally the same, why can't their immune systems just quickly learn to handle something like the common cold? Can't they simply develop antibodies? Why does it become fatal when introduced to a new group?

Thanks!


texts: How fast is water transported from roots to leaves?

texts:
I understand basically how water transport from roots to leaves through the xylem works, but I have no idea of the timescales involved.

How long does it take for water to get from root tips to leaves? How does this speed change in different parts of the plant? How does it differ between different plant types? How is it affected by plant size?

Also, I guess it changes from relatively fast in the middle of the day to almost zero at night, but how does it change during a normal sunny day (e.g. sinusoidal? More like a square wave?)


texts: Are mature trees as susceptible to mutation from exposure to radiation as seedlings?

texts: If a plant, say a ficus or a teak, as a sapling were exposed to radiation, and a tree of the same species were present at the same distance, which of the two would be more likely to mutate?


texts: Why do I feel nauseous at the sight of blood, despite not being afraid of it?

texts:
Every time I ask google this question, all it spits at me is info on blood phobias ^-^; basically, I've always been hugely interested in morbid stuff, but I noticed that I always feel sick when interacting with any sort of gore IRL - when I volunteered at a hospital to keep patients company, I had trouble staying calm around patients who had been in accidents when they were getting their bandages changes, or around patients who've had surgery when they drained their tubes. Yesterday in Anatomy we dissected a pig's heart, and I was super excited until we finally got them & I felt sick seeing it! I'm just confused because mentally I'm fine & don't mind being around that stuff, but physically I feel ill & its pretty annoying tbh :/

If it helps explain it at all, I do have issues with vasovagal syncope & tend to faint when getting blood drawn & being in a very warm, humid place, & I kinda have the same feeling with it? I'm not afraid of needles or heat, but I feel sick in those situations & end up fainting


texts:
According to this video, butterflies sometimes drink blood. Do they have the organs necessary to digest blood? I thought they eat only salts and nectar, which are easy to digest compared to proteins.

@aandreev

100mg/dL is the human blood sugar content (I assume it is similar in other animals). Afaik. sugar energy density is about 4kcal/g. A butterfly is about 1g of weight, which means 1mL if we count with water. So it can drink around 0.5mL of blood. That means 0.5mL×100mg/dL×4kcal/g = 0.002kcal = 8.4J. The top butterfly speed is about 12 mph, so I think we can count with 6mph by an average butterfly, which is about 2.7m/s. So it needs 1/2×1g×(2.7m/s)2 = 0.0036J kinetic energy to move and 1g×9.81m/s2×1m = 0.0098J potential energy to keep the 1m height of flight. I think we can guess that it loses this kind of energy in 2secs, which means it needs 0.0134J/2s = 0.0067W power to fly. So the 0.5mL blood means 8.4J/0.0067W = 24925s = 21min of flight time, which is not much compared to nectar (30g/dL$, $2500J$, $100h). Ofc. this is just a very rough estimation (the real flight time is probably much lower) based on data coming from non-scientific sources, but I think you can see the difference.


texts: Why are Natural Killer cells considered cells of Innate immunity?

texts:
Kuby Immunology says

  They (NK cells) do not express antigen specific receptors and are considered part of the innate immune system.

Though
 they also have receptors for antibodies that bind to NK cells and help detect antigens or pathogenic cells that are killed by the secretions of their cytotoxic granules.

Couldn't we then call them cells of Adaptive immunity?


texts: Loss of allelic variation per generation of full-sib mating

texts:
If we take a male and female, cross them, and collect one son and one daughter to produce the next generation (and continually do this for many generations) - (full-sib mating design) how much genetic variance is lost per generation/how do we calculate this?

Assume all sites initially have allelic variation, and we imagine a diploid sexual species.


texts: Why nerve fibre is infatiguable?( is my conjecture correct?)

texts:
According to this:

  A nerve fibre cannot be fatigued, even if it is stimulated for a long time. This property of infatiguability is due to absolute refractory period.

How is refractory period related to infatiguability?

My attempt: If there were no absolute refractory period, then there will not be closure of Na+ ions into cell, so there will be temporary deficiency of Na+ at that location, now if a new action potential arrives at that point then , due to lack of Na+ there will not be further conduction of it.

Is my conjecture correct?


texts: What is the actual function of HDLs and CETP?

texts:
I know that HDLs collect cholesterol from peripheral tissues and transport it back to the liver using SRB1 - Reverse cholesterol transport and dumping it in bile. So the tissue is producing some extra cholesterol (why would it? apart from some atherosclerotic condition) and our HDL gets it back to the liver.
This is a bit fine. But then there is CETP which is giving back the cholesterol to VLDLs.
So is it not confusing that our HDL took the excess cholesterol from the tissues only to give it back via VLDL?

So my questions -

Q1 - Why would a tissue have extra cholesterol?(when excellent feedback mechanisms exist - eg. SREBP SCAP INSIG path). Does the HDL pathway make sense only when there is some atherosclerosis?

Q2. Reverse Cholesterol transport refers to the SRB1 part only or SRB1 + CETP combined?

Q3. What is the rationale behind handing over the cholesterol back to VLDLs by CETPs? I know that considerable LDLs get back to the liver too but isnt just SRB1 pathway just fine? Why is it so important to equilibriate your lipid content across lipoproteins? I understand this is the mechanism how torectrapib works but presence of CETP in the body signifies that it must have some ulterior motive, right?

please help :)


texts: What happens to a virus SARS-CoV-2 on an object?

texts:
Many articles say that "the coronavirus" — they probably speak of the SARS-CoV-2 — can "remain alive" for so many hours on some surfaces, so many days on some other surfaces. For example, "the virus lives 5 days on glass".

I think that this is a bad choice of word. All these articles speak about the virus SARS-CoV-2 as if it were a living being. But I think it is not a living being. The virus SARS-CoV-2 does not "live" on a glass surface. It just is there.

When a virus SARS-CoV-2 is on an object, what happens to it? If it is not there anymore after 5 days, why? What does time do to a virus?


texts:
What exactly is a calorie? When burning calories, do we always lose fat?

I have tried many apps to measure calories, do they give exact amounts? How many calories should be taken a day?


texts: Bacteria utilize short chain fatty acid as energy source

texts: I'm doing research about the short chain fatty acid producing bacteria. I studied 7 short chain fatty acid (acetic propionic butyric isobutyric valeric isovaleric and captionic). and I found that the bacteria produced all acid in 8-12 hr incubation time  and after that all short chain fatty acid rapidly decreased, except acetic acid slightly decreased. How can I explain this results?  and I did my experiment under anaerobic condition.


texts: Does the repellence of an insecticide affect its efficacy (measured in insect mortality)?

texts:
I am currently working on assessing the efficacy of a suspected insecticide on a particular species of insect. I happen to be looking into any repellence caused by the substance. I test for both effects at the same time by putting that insect in a no-choice bioassay. To be specific, my assay set-up consists of a petri dish, and the test article treated with the test substance is placed on one side of the petri dish. Insect species X is introduced into the petri dish, and every 24 hours, I get to count and remove the dead ones. All these are repeated for different concentrations of the test substance.
What I found is that mortality (proportion of insect X killed) initially increases with concentration, but then decreases after a particular concentration. I also found that repellence increases with the concentration of the test substance. So, what exactly is happening here? Is the repellence of the test substance having an effect on the mortality, such that repellence is causing a decrease in mortality?


texts:
I saw this large bird gliding fairly low over the trees while hiking in the late afternoon in some hills near Taipei recently. It seemed quite large compared to what I normally see here. It's quite difficult to gauge, but I'd guess the wing span was one meter or so.

It made that shrill, descending, single "peeeew" sound that I associate with birds of prey (probably mostly from old movies or TV commercials).

Is it at all possible to guess if this is a hawk or an eagle from these cell phone snapshots? These are cropped out of the full resolution originals. A half-size original for scale is also included.


texts: I hope this isn't inappropriate for the forum - I'm trying to find a book that I read several decades ago, possibly 40 years or so. As I recall, it was a systematic treatment of the whole of the palmaceae. The title was fairly brief, possible just the word 'Palms'; however, I don't think it was this one Martius: The Book of Palms. (I could be wrong, though.) Any ideas?


texts: Why don't we find animal corpses and skeletons all throughout the woods?

texts:
Where in the forest do wild animals die?  I rarely (occasionally, but rarely) come across animal bodies.

Where are the large skeletons of bears and deer?

Detectives often investigate human bodies that were dumped months earlier.  They've partially decomposed, but are still mostly there.  Why?


texts:
Wikipedia says

  Antibody opsonization is the process by which a pathogen is marked for ingestion and eliminated by a phagocyte. Opsonization involves the binding of an opsonin, e.g., antibody, to an epitope on an antigen. After opsonin binds to the membrane, phagocytes are attracted to the pathogen.

But why is it necessary for pathogen to bind with opsonin? Can't phagocytes attracted towards pathogen without opsonization? Simply I want to know what is significance of opsonization?


texts: What might a supposed “tree enzyme” be — injected into a Morton Bay Fig tree?

texts:
I was recently visiting Fremantle in Western Australia and noticed a large Morton Bay Fig tree in Kings square in the centre. Apparently the health of this tree had been declining, but they hope that recent treatment will lead to an improvement.

The notice by the tree said this was by “injection of a tree enzyme”. I also found the following quote on the City of Fremantle FB page:

  To improve the tree’s absorption of nutrients which will help it grow stronger, the bioscientist has given it a ‘booster’ enzyme injection. This enzyme naturally occurs in trees and is an additional boost that will hopefully help the fig tree recover and flourish again this spring.

Well trees have enzymes like any other living thing, but I find it difficult to imagine what enzyme injected into a tree would get transported through its system and help it heal. Is there anyone in silviculture (or WA) who has any idea what this was?


texts: What's the difference between a lymphocyte and a plasma cell?

texts: According to my understanding, lymphocytes is the broad terminology for both T lymphocytes as well as B lymphocytes, while plasma cells refers to mature B cells which produce antibodies. But then why are they mentioned separately, doesn't a plasma cell come under category of lymphocyte?


texts: The Fish-Tetrapod Transition, evolution of the "elbow" in Stem Tetrapods

texts: The Acanthostega and Tulerpeton limbs seem to form "elbows" in an axis perpendicular to the flexor and extensor plane of the fin. They seem to "flex" their "elbow" forwards, pre-axially. And, I assume, keep it permanently "flexed", a bit as if their humerus, ulna, and radius has been one single "V-shaped" bone. This adaptation positions the primordial hand forwards. Is this pretty much correct? Why I wonder, I always understood elbows as bending in the flexor/extensor plane, but in the first terrestrial life it seems to be in the pre-axial/post-axial plane. That probably has implications for how limbs continued to evolve, and for the embryogenesis of limbs in mammals like humans. I found that interesting.


texts: Can a cell completely lose the ability to undergo apoptosis?

texts: What I mean is - can a super-cancer cell completely lose the ability to kill itself, losing all apoptosis-related mechanisms and becoming eternally resistant to any drug that tries to induce apoptosis directly or indirectly.


texts: How can highly virulent but uncommon diseases (like ebola) maintain a stable equilibrium?

texts:
I'm wondering how can very uncommon diseases remain in a relatively stable equilibrium. For example, if it started to spread, the spread could accelerate and become an epidemic. However, if it doesn't spread, why doesn't it wither away?

As I understand, the ebola for example, is highly contagious, nearly always fatal, and kills quickly. So quickly, hat the target has not much time to pass it on to others. If it spread just a little better, it would become an epidemic, just a little slower and it would disappear. How is it possible, that its spread did not change significantly in the last couple of decades? It kills a few dozen, maybe a few hundred people per year, these numbers remain largely unchanged.


texts: Where does my extra blood volume go after giving birth?

texts:
I'm pregnant. I've learnt that during my pregnancy my blood volume will increase by 50%. https://www.ncbi.nlm.nih.gov/m/pubmed/4075604/

So I'm wondering, what does my body do to decrease my blood volume after I give birth? Where does all that extra blood go? I would imagine I lose some during labour, but I seriously doubt it's all of it.


texts: Hi everyone! Here is a diagram of a genetics complementation problem. My main concern is regarding number 3d. I'm assuming that in this case, it would be complementary interaction and thus exhibiting a ratio of nine to seven. because if we cross F1, 3 will be mutant while one will exhibit wild-type phenotype. Is this right? Thanks in advance!


texts: Human disease and associated phenotype database?

texts:
Does anyone know of any good databases that contain symptoms for diseases and other ailments in humans? I've tried working with UMLS, but thats been impossible to work with. I've also tried working with the disease ontology website (http://www.disease-ontology.org/), but that doesn't seem to be very...comprehensive...in terms of symptoms for the diseases they have.

I've tried looking at the the disease database (http://www.diseasesdatabase.com/), but they are reluctant to hand over the raw data, if I understand correctly.

Anyone have better ideas?


texts: Is lung size/shape a factor in long-continuous running of animals?

texts:
Apart from other factors, does lung shape/structure/size play any role in long-continuous running animals.

Is there any similarity in lung structure between different long-continuous running species?


texts: Calculating gene separation -a genetics problem

texts:
I am really struggling with genetics. In particular, I have the following question

Now I am OK with calculating the separation of genes in centrimorgans when I have data like so:

But in the first question, I am not sure if this is even possible. I gone through many books to no avail.

The conclusions I have been able to draw so far are:

these mutations are carried on X due to similar proportions of males and females exhibiting the characteristics.
the order of genes seems to be white, miniature, forked due to white miniature and forked miniature occurring much more frequently than white forked. Also it seems that white and miniature genes are close than miniature and forked as the former is a more commonly exhibited phenotype.

All of this is alluding to me somehow being able to figure out the separation of the genes, but I do not know how. Or if this is at all possible in this problem..


texts: Average number of gene products in (a) eukaryote(s)

texts:
Due to alternative RNA splicing, it isn't uncommon to ultimately find multiple gene products expressed from one gene in eukaryotes. I'm looking for a reference value for the average number of final gene products expressed per gene for:

... a particular eukaryote (preferably humans).

This can't be too hard to do for one species like humans. I would expect the following formula to provide me with a rough answer. Is this correct?

(number of distinct proteins + numbers of distinct non-translated RNAs) / number of genes

... all eukaryotes as a whole.

This one is slightly more problematic.


texts: Can a cell culture insert plate be used with a vacuum manifold?

texts: There exists 96 well plate setups for use with vacuum manifolds. Is it possible to use 6/12/24 plate inserts with the same setup?


texts: What will happen when humans are injected with plant growth hormones

texts:
Will plant growth hormones (PGHs), (let us consider auxins for example) poison our body or not?
I do realise that when you eat a shoot, auxins get digested and are less likely to be poisonous but when taken as an intravenous injection can auxins cause some changes to the body?
I mean even if they do not poison a body, some osmotic changes are bound to happen.
According to this link, if the water was injected in not so little amounts it is bound to cause cells to burst.

EDIT: Now according to this link, plant hormones are actually beneficial to human body.

How is it possible if they don't have any receptors in humans or any other vertebrates?


texts: Human female chest model or data representation?

texts:
I am looking for professionally used representation of female chest (I know how it sounds ;). Generally - a model comprehensive enough to effectively represent human chest, with focus on breasts.

The data it needs to represent are at least: width, height, depth, distance between cardinal points, so on. I do know there's a questionnaire for patients willing to undergo an implant operation - I'm looking around for something similiar. Optimally the model would be directed towards computer represenation.

With that in mind, I've checked some computer implementations:

SOFA (seems promising, but somewhat generic),
MakeHuman (nice
customization, but again, pretty general).

I do not know whether this question is in scope of this site. If it's too specific, then consider the simplified: what are the methods used to describe female chests OR what would be a good source of information about these methods?


texts:
Good morning,
I am new to molecular biology. The question might be silly but i would like to know the answer. I have three 60mer single strand synthetic oligonucleotide. Namely Tag 1 - 3. My goal is to assemble these three together by pcr. So i designed two primers having overlap of 18nts from each tag 1 and tag 2 and then Tag 2 and tag 3 ( i mentioned the orientation of my primers). What is the best way to assemble. I read about PCR- based two-step DNA synthesis. But i would like to know more about this.
If you have any questions please feel free to post. Thanks and looking forward for your valuable answers
[]


texts:
This plant popped up as a volunteer in a flower box in Winnipeg, Manitoba.
It is roughly 6-inches tall by 6-inches wide.
What is it?


texts:
This year in October, I saw a lot of robins, male and female, finches and chickadees, and geese flying south.

Surprisingly I didn't see many juveniles from previous broods. My guess is that juveniles are harder to see.

And the robins were flying above me, looking for worms below me, and most ended up in tall shrubs. The finches stayed in place longer than the robins.

So why this big congregation of birds when it is still going to be relatively warm for most of the fall(which it ended up being)?

I live in ohio where it usually gets down to -4 in January and 90+ during the summer.


texts:
I've seen plenty of speculation online, but does anyone know of a scientific study or have a definitive argument?

I'm thinking probably not sweet, because the deoxyribose sugar is bound in the structure of the helix. Salty, due to group I counterions? Bitter due to the alkaline phosphate groups? I'm guessing not sour, because despite the name nucleic acids are in their conjugate base form at physiological pH. I've read some nucleotides can activate the umami/savory taste, would this be significant?

I am aware essentially everything we eat contains DNA, but I'm interested in the taste of DNA itself, pure/isolated if necessary you like.


texts:
Most of the enzymes have a certain lifetime. I want to know that do molecular motors have a certain lifetime after which they degenerate? Any reference will be appreciated.
Basically, I just want to model a molecular motor with a finite lifetime for that I need a certain numerical age span that they follow or maybe some exponential decay model.

Furthermore, as suggested by WYSIWYG I have got a particular term for the protein lifetime with which I can search. I will try to find the answer myself and post it.


texts: How to determine the probability that a mutation is lost / fixed?

texts:
I have a question about how to determine the probability that a mutation is lost or fixed after 1 or 2 generations in population genetics.

Let's say we have a randomly mixing population, with N diploid individuals (N=5), and there is one mutation that appears. I know it should follow a binomial distribution, but I also heard it may follow a Poisson distribution... and all I feel like saying is that the probability to get fixed is the same as the frequency at time 0, which is 1/2N, or here 1/10.

Furthermore, how do you calculate the probability that it exists in 2 copies?


texts: Crossing white eyed Drosophila with sepia eye

texts:
So, I'm doing some drosophila experiments with my high schoolers and I had really poor production of wild type individuals for doing the experiment resulting in not enough to cross with everyone... I am trying the following crosses and hoping the kids can still learn from it, but wanted input from any fly-herders on what I can expect with the first two  crosses....

Sepia males x White Eye females

Sepia females x White Eye males

Dumpy males x Wild-type females

Dumpy females x Wild-type males

I don't think the gender separation will make any difference except in the white x sepia crosses since it is X-linked.
What should I get in the sepia x white crosses? Since they both control eye color and are both recessive I'm not sure. Am I correct that w is epistatic, thus should block sepia in an x-linked manner (same as if I had used wild-type instead of sepia)?
I assume the Dumpy x Wild-type will go by the books (F1 all wild-type with F2 3:1 ratio). Fingers crossed.


texts: Software to calculate Fst from sequence data

texts:
I'm looking for a software to calculate Fst from 3 loci DNA data of individuals from a metapopulation. I don't have any prior on the population structure (have no idea of the number of subpopulations for example)

I've been looking at FSTAT but it doesn't run on MAC.

Do you have any easy alternative?


texts: Why our bees might have suddenly disappeared

texts:
We have a large garden in Bedfordshire, UK, next to woods and to arable fields currently planted with intensively farmed rape. We usually have many bees in the garden. Earlier this year, things were humming along as usual. A cotoneaster bush in flower had perhaps a hundred bees on it at once, of at least 6 different species.

Now, in July, we have lavender and clover in full bloom, normally swarming with bees. But, not now. This morning (overcast and warm) there were two bees on a lavender bush covering two square metres. I can walk for minutes in the garden without seeing a single bee. The leafcutter bees have left no holes in our rose leaves this year.

The nearest managed hives are about 800m away. It's not just a managed hive that has gone, the bumblebees that nest in our garden have gone too.

The rape flowers are long past. I don't know what might have been sprayed on the rape.  Our garden is organic.

Wasps are down too. This is the first year in the last twenty that there are no wasp nests in our outbuildings. There are, however, plenty of flies.

What might have caused such a sudden and unusual population change? Among multiple species of bee from multiple sources, between April and July?

Could it be our globally-warmed weather? June and July have been wetter and warmer than usual, although not exceptionally so.

Are UK farmers allowed to use an insecticide on rape that could kill most bees?

Or is a dramatic in-year population change in bees a routine, if uncommon, event?

Thanks!

Update August 17 2016

Our garden bees do seem to be gradually recovering - nothing like most years, but a few bees are coming back. Other nearby houses, at least 400m from the nearest rape field, have plenty of bees.


texts:
I found this bug dead in my house in Mississauga, ON, Canada.

I didn't have a ruler around so a regular toothpick was used to show the size.

I'm thinking it's a pill bug but I want to make sure.


texts: Do humans contract more physical sicknesses and diseases than animals do?

texts:
I wondered: If I get into the library and look into the medical section it is evident that there are thousands and thousands of different human physical diseases. But if I look into the section of animal diseases it is by no means as large as the human section.
But humans are by no means the only beings with extraordinarily cell complexity. Many other animals have an equal amount of cell complexity. So shouldn't other animals have an comparative equal amount of diseases ?

Naturally as humans we are much more interested in human physiology which would explain the discrepancy. But is there any evidence that animals, especially mammals, have not an equal amount of (still unknown) different diseases ?

Remark:
While a bit similar, this is not this question:

Why do humans seem so much more prone to disease than animals?

I am asking about the quantity of diseases, not if humans are especially prone for diseases.

ADDENDUM:
The difference between the questions is like
"Is building A more prone to fall in natural catastrophes than other buildings because it seems like it ?"

and
"How many faults have building A in comparison to other buildings ?"

A correct answer to the first question is: "We made a statistical comparison and building A is more/less/equal prone to fall in a natural catastrophe. The impression is wrong/right."

A correct answer to the second question is: "Building A has in fact a mean approximately 13 000 faults while other buildings have only 5400 faults. But the reason can be that the other building are inspected with less care." Or "No, they both have very likely something like 9000 faults".

It is a completely different question. The second question does not ask for the severity of faults. It could even be that building A has more faults while being more secure because the faults itself are much less severe.


texts: Why would a single celled organism evolve to be multi-celled?

texts:
I read a story this week on Richard Lenski who has been 'evolving' E. coli for more than 50,000 generations now.  One comment I read was from someone who doesn't accept Evolution who pointed out that we haven't seen a single celled organism 'evolve' into a multi-celled organism.  Another person responded and said that a bacteria is not going to evolve into something that isn't a bacteria.

So, if Evolution created single celled organisms and then multi-celled organisms how might that change have happened?  And is it possible to recreate that set of driving forces to make a bacteria something other than a bacteria?

To that end, what advantage does being multi-cellular have over being unicellular (if that's even a word)?


texts: Evolutionary origin and exogenous cues of ~28 day infradian rhythm?

texts:
The most obvious example of an approximately monthly biological cycle is the human menstrual cycle. My questions are the following:

Is it known when and where this cycle or one like it arose?
What exogenous cue(s) (if any) is/are this cycle based on? The moon's
orbit around the earth is seemingly obvious however the only cue that
I can think of that would be easily sensed by organisms is variance
in night-time illumination, which seems like a very weak phenomenon
when compared to day/night and seasonal cycles. King and neap tides may be a suitable cue however they have a half-monthly modulation.
The moon has been steadily retreating from the earth over the course
of its history, which means that months have been slowly getting
longer. Is there any fossil (e.g. biogeochemical) evidence of
organisms with biological cycles in synchrony with a 'short month'?


texts: Where can I find comprehensive data on animal distribution?

texts:
I'm looking for vertical distribution or tidal height of several intertidal species, specifically from the Pacific Northwest.

I considered looking for published research for each species however, my search likely would not be comprehensive and perhaps be biased in site-specific differences.

Is there some kind of open database where I can find this information?

I've found that EOL draws some data from the Ocean Biogeographic Information System, but when I go to the site directly, I can't find the tidal height data. I've also looked through suggestions in response to this question but none are applicable.

Any help with these databases or suggestions on other relevant databases would answer my question.


texts: What is the name of this green plant with fat leaves with green color fruits?

texts:
Location: South India,Metropolitan

Year: 2017

It look like Almond tree, but small doubt not sure.


texts: Is there a difference between pig and cow anatomy that makes religious slaughter of the latter less painful?

texts:
This question is not for the squeamish. I was told that non-Kosher animals like pigs have a different anatomy in their neck compared to kosher animals like cows such that the Shechita method of religious slaughter (a very sharp knife held on the neck only by the weight of gravity rapidly going back and forth in a single cut that drains blood and results in an "instant" drop in blood pressure in the brain), while causing pain in the non-Kosher animals, doesn't cause pain in the Kosher animals. Is there such an anatomical difference and thus difference in pain?

(If this would be more on-topic at Skeptics.SE, let me know.)


texts:
I stain an unknown acid with purple dye. Later, you find the cell in two organelles. What are they?

I am guessing that one of them is lysosomes, because they break down unwanted elements. What would the second one be? Mitochondria?


texts:
I have found the following pictures representing cysticercoids of Eucestoda.

If I correctly understand the right part of the picture, I would say that the development of the scolex is portrayed on the right, as the formation of what I think to be two acetabula shows. Nevertheless, with respect to the images on the left, it is totally unclear to me, since the text says nothing about it, what the structure that seems to be encapsulating the animal is.

I know that cysticercoids develops from an oncosphere, but I do not know whether that sort of capsule that seems to be enveloping the animal is a part of what was the oncosphere's tegument -the embrionophore- that it can have gone out of and is entering again...

Does anybody reading this question know more about it? I thank you very much for any answer!


texts: Wasp nest destroyed by some big wasp like insect: is that the queen?

texts:
I had a small wasp nest in my bathroom. Initially there were only two to three wasps but the number increased to eight.

Today morning a big wasp-like insect (shown in the image below) came to the nest. I thought that it was the queen but it ate all the larvae and destroyed the nest.

Can someone please tell me if this is a normal behavior of a wasp? Is the "big wasp" their queen or another species?


texts: Why are animal births not taken as seriously as human births?

texts: When humans give birth, more than often medical assistance is needed. Others gather around and frantically look for any way to help. But when an animal gives birth, it is usually seen as a moment where you give the female its space and let the birth occur naturally and without any assistance. The animal is of course in serious pain just as a female human but this is more than often not taken into account. Why is it that animal births are not taken as seriously?


texts: Can I kill bacteria with distilled water?

texts: Given that bacteria are hypertonic (contain more salts) compared to distilled water, and that they rely on ion concentration differences across the plasma membrane to survive, can I kill a bacterial solution by adding an excessive amount of distilled water to make them explode? If I add distilled water on a surface, are the bacteria on it going to die?


texts: Can a small polypeptide fold over itself and have a tertiary structure?

texts: What I want to know is if polypeptides (those which are not considered as proteins) can also "exhibit" a tertiary structure.


texts: Why do skinny people live for shorter than the norm even though calorie restriction extends life expectancy?

texts: If I understand correctly, calorie restriction may extend life expectancy slightly (not proven exactly how much for human). But according to the statistics, skinny healthy people have even shorter life expectancy than healthy, slightly obese people. Could you explain why this is not considered as contradictory?


texts:
When I did a research, most of the sources say that orca is one of the fastest. But I could not find a source that says it is actually the fastest.

Some sources say that Dall's porpoises rival orcas in speed. And there are other kinds of porpoises and dolphins that comes into question.

Is there any scientific research with measurements? Or does anyone have any detailed knowledge about this topic?

(Also it would be nice to know top 10 fastest marine mammals, so the question becomes: what are the fastest marine mammals?)

Note: This scientific research might be difficult to conduct also so you can explain the situation as well.


texts: Would short term increases in oxygen lead to beneficial effects?

texts: After some thinking, I am wondering if having a 30% atmospheric oxygen concentration (or some other concentration) for a short time would increase the regeneration of energy in a body? It seems like it does have some mental effects, but I haven't found any other positive effects on the body.


texts: fibrinogens and fibrins - are they the same molecule?

texts:
Some proteins are "activated", like fibrinogens; they are turned into fibrins by thrombins, and then the fibrins can aid in blood clotting.

Are fibrinogens and fibrins the same molecule, just in different states? If so, are all "-ogen" ending proteins and their activated forms the same as well?

If they are different molecules, why do us even bother to convert a protein into anotherto work, instead of simply activating a protein?


texts: I'm new to neuroscience research and came across a term called negative spikes (sometimes also used in conjunction with terms biphasic spikes or positive-negative spikes), but could not find what it meant from scientific papers. Can a spike occur in a negative direction (hyperpolarization from the resting potential first, followed by depolarization) or does this term mean something else entirely?


texts: Does Povidone-Iodine that penetrates through the skin stays in the body (cells, liver etc)?

texts:
Here it says on povidone-iodine:

"Route of Elimination: Povidone-Iodine is intended for topical application and is not eliminated"
"Clearance: Povidone-Iodine is intended for topical application and is not eliminated"
"Metabolism: Povidone-Iodine is not absorbed or metabolised"

Now Povidone-Iodine is a very widespread antiseptic used directly on open wounds and there are cases of people using it as a disinfectant before and after microneedling (ie: inducing micro-injuries with a dermaroller device over the skin) which ensures penetration of the substance through the skin and blood circulation and into the body.
What happens with it once it's inside the body - even if some is excreted what happens with the rest which isn't? does it forever lingers within the body (cells, liver etc)?


texts: For how long would a flu-contaminated parcel be an effective disease vector?

texts:
A parcel has been delivered and contaminated by a person who has the flu.

For how long would the parcel be an effective disease vector?


texts:
I live in the midwestern United States.  I cycle to work, sometimes on heavily wooded roads, and I can't help but notice that in most places within the surrounding deciduous forests Pine and evergreen trees don't seem to be doing so well - the few that exist don't look too happy.

In some places, however, there are majestic stands of pines - often completely free of the "seasonal" variety of trees.

Why is this?  What allows the slow growing pines to out-compete the other arboreal denizens of the forest?  And generally in such particular areas?

Thanks, this is killin' me...


texts: I was walking through a small park when two crows started cawing at me, and followed me, flying from tree-to-tree as I walked. I speculate that this is a territorial or protective behaviour, but what I found different was the crows were violently pecking the branches nearby them. I have no memories coming to mind of seeing this behaviour beforehand. I speculate that this behaviour could be threat displays, but a quick search on Google did not reveal to me any authoritative studies on this phenomenon. I'd appreciate more information and sources.


texts:
I've been reading a curious paper about the use of cannabis, and one of the passages piqued my interest:

  There’s also been a lot of work done on another constituent of
  marijuana, cannabinoid, which is not psychoactive by itself. A lot of
  research has shown that it’s a great anti-inflammatory, it’s a
  neuro-protectant, and it may be what gives medical marijuana patients
  relief from things like epilepsy and anxiety

Has there been any scientific evidence that links inflammation and anxiety?

Source:
Cannabis, Forgetting, and the
The Botany of Desire


texts: How is it possible for monosomies to occur?

texts:
I was taught in biology class that a cell dies if it doesn't have at least one copy of a chromosome "type". If this is the case, that means that:

Zygotes without a copy of a specific chromosome (for example chromosome 21) die.
But this would also mean:
Gametes without a copy of a specific chromosome would also die.

If this is the case, how is it possible for monosomies to occur? Wouldn't there have to be at least one haploid cell with (n-1) chromosomes when fertilization occurs?


texts: Bacterial cell lysis - what solution to use?

texts:
I am trying to determine how quickly detergents act on bacterial cells (cell lysis). I would like to compare some detergents at difference concentrations for bacteriolytic activity. I don’t care about all metabolites inside the cells (proteins, DNA, etc…). Many publications suggest that often more complicated solutions are used. My first thought was to use a simple prepared detergent in PBS or saline for lysing the cells. Do I need a complex solution to lyse the cells?
Could someone please give me a suggestion? Thanks in advance.


texts: Do the mother's genes determine the sons' (heredity) intelligence more than the father's?

texts:
It is a general belief that a person's intelligence is determined by both nature and nurture.

I can find a study by Turner 1996 ( in fact, this is the motivation of this question), which makes the claim that since several genes which determine intelligence appear to be located on the X chromosome, the one men inherit from their mothers, and since a man only has one X chromosome inherited from his mother, so that's why mom's intelligence is very important to her sons, even more so than the father's!

Thus, my question is, do the mother's genes determine the sons' inherited intelligence more than the father's, as claimed by the above paper? In other words, a man inherits less intelligence from his father than from his mother? Note that I don't discount the possibility that the father could have helped to raise his son's intelligence by actively nurturing him in the correct way, just that as far as the "intellect genes" ( if there are such things) are concerned, the father plays less role than the mom.

A similar question is asked at Skeptic.SE, but it is geared more towards the contribution of mom's genes against all factors that account for son's intelligence, nurture and nature. My question is focused exclusively on the contribution of mom's genes vs. dad's.

Any new research on this front?


texts: The role of duration of infectiousness in SIR models

texts:
I refer to J.H. Jones' Notes on R0.

The basic SIR model - as described in Jones' Notes - considers three factors that make up the reproduction number:

$\tau$ = the transmissibility (i.e., probability of infection given contact between a susceptible and infected individual)
$\overline{c}$ = the average rate of contact between susceptible and infected individuals
$d$ = the duration of infectiousness

The (basic) reproduction number then is

$$R_0 = \tau \cdot \overline{c} \cdot d$$

The duration of infectiousness enters the basic SIR model as the so-called removal rate $\nu$ which is nothing but the inverse of the duration of infectiousness: $\nu = 1/d$:

$\frac{ds}{dt} = -\beta s i$

$\frac{di}{dt} = \beta s i - \nu i$

$\frac{dr}{dt} = \nu i$

with

$s$ = the fraction of susceptible persons
$i$ = the fraction of infected persons
$r$ = the fraction of removed persons (recovered or died)
$\beta = \tau \cdot \overline{c} = R_0/d$ = effective contact rate or infection rate

  My question concerns the way that $d$ enters the SIR model, because I
  find it not so plausible:

  to consider all persons that are infected today and take a fraction $\nu$ of them that will have recovered tomorrow.

  Wouldn't it be much more plausible

  to consider all persons that became infected $d$ days ago and let these be recovered tomorrow?

The latter approach would be especially valid when the death rate can be neglected, i.e. when "removed $\approx$ recovered".

My impression is that most papers using a variant of the basic SIR model let enter the duration of infectiousness in the first way - leading to significantly different predictions than in the second case.

I implemented both and this is the difference (only due to the different ways that $d$ enters the progression formula, i.e. the values of $\beta$ and $d$ are fixed):

(In case that you wonder why the curves oscillate: I have modelled some sort of acquired immunity with finite duration of only some month - but in the very same way in both cases.)


texts: Why are treatment periods with antibiotics longer than 1-2 days?

texts:
Antibiotics are given prophylactically for several indications (e.g. prior to dental surgery).

  Why are the treatment periods for prophylactic antibiotics much shorter than when treating an infection?

Example: Prophylactic antibiotics may be the day before surgery, but in the case of infection, they are often given for 10-14 days.

Is there something different about pre-infection bacteria (or the body) compared with after the infection has set in?

Looking for general concepts here, as I recognize there are many different types of bacteria and antibiotics.


texts: Decomposition Rate of A Body In A Wet Environment

texts:
I have a photo of a decomposing dog which is in a water logged environment. My peers and I are debating how long that body has been decomposing. They are saying it is at least a year old. I however think it's much more recent (1-3 months).

My understanding is that when a body is put into a wet environment either partially submerged or fully it speeds up the decomposition process provided the water is not lacking oxygen such as if it was deep on the ocean floor.

The carcass has its skull fully decomposed, which I think is due to the bacteria rich water having more access to surface area through the various orifices and also the skull having much less flesh than the rest of the body.

The torso looks for the most part intact, and I don't see any bloating from gas buildup (not sure when and how long such a feature would be present), and there appears to be a pink area which could be muscle.

Would these features be typical of a recent death in this type of environment or am I overlooking some other important processes that could be speeding up or slowing down the decomposition?

Photo (image unboxed in case graphic for some viewers)


texts: Where did the term "vegetative nervous system" come from?

texts: I am interested in the origin of the name. I am aware that Reil coined the term in the 1800s, but want to know why did he choose the term vegetative. I have not been able to find an answer to this question. Today it is called the autonomic nervous system.


texts: Find how much times blood is filtered in the kidney?

texts:
The blood that circulates in our body is about 1/12 of our mass. If the kidneys filter 7.5 liter of blood a hour, then how many times does it filter in the kidney the whole blood of a person will mass 60kg?

Here's what my teacher did:

1/12*60=5 liter blood

0.55*5=2.75 liter plasma of blood.

The plasma is filtered 60 times is 24 hours. (how did she find that?)

24 hours ->60 times the plasma filters

1 hour -> x

x=2.5 times

Do you understand her explanation? What should I do next?


texts:
I've never seen anything like it, although I suppose it could be a wasp or an ant with wasp-like colour bands. Found in our garden today (Cambridge, UK). It's about 1.5 cm (half an inch) long.

Thanks!


texts: Can/Do any spiders "release" their own web in the presence of a threat?

texts:
Preface

We live in the north eastern US and have a spider that has setup shop next to our front door.  I've lived in this area my whole life and she's the largest spider I've seen.

We're too interested and afraid to do anything but let her be, so we've been watching her for the last couple of months.

The "Event"

My wife almost bumped into her web while we were looking for our cat tonight. (I mean she was really close). The spider was hanging around in the center of the web at the time.  A short while later my wife saw the spider scurrying furiously and then she crawled back into her hiding spot behind the shutter.  Next time I looked over, her web was completely gone - neither of us think we got close to it again during that short time.

I'd also like to point out that it was a bit gusty tonight, a rain storm was probably about an hour away.

We are wondering if something happened to her web, or if she took it down intentionally.  If she did, is this behavior common in spiders?

Other Information

She's got a blackish/yellowish bulbous body with the same color striped legs
She's about the size of a ping pong ball (including legs)
She hides during the day behind the shutter, but always comes out when the sun starts setting.
Unfortunately I have no pictures of her that aren't the underside, she never comes around the front of her web.
She builds a "classic" looking web, a hair longer than a foot in diameter with a couple of longer guy lines out to the door and the stoop. There are never any messages written in it.
She either never catches anything, takes her food back into her little den, or eats very quickly because I've never seen anything wrapped up in her web.
Our cat found his way home a couple of hours later

Photo

Thanks!


texts: Do reproductive organs function before puberty?

texts:
Testis means one of the two male reproductive glands that produce spermatozoa and secrete androgens.

Ovary means one of usually two organs that produce oocytes and secrete oestrogen and progesterone.

Do these organs function before puberty?


texts: Why does the side of the mebrane of a neuron with a high concentration of positive ions become electrically negative?

texts: I am having a real hard time understanding why the side with a high concentration of positive ions becomes the negative side of the membrane (in a neuron). This website http://www.st-andrews.ac.uk/~wjh/neurotut/mempot.html says its because "...the positive ions flow away from the high concentration side". But I still don't get it. Wouldn't it make more sense to then say that the high concentration site (more positive ions) has more positive voltage?


texts: Is it possible to consume O2 via a pill form to inhibit the need to breathe?

texts:
Just wondering if it would be theoretically possible to consume oxygen via O2 pills, in the effort of being able to hold one's breath without limit.

Totally just curious.


texts: Scenario: I'm about to fall asleep with the T.V. on. Having completely forgotten that it was, no longer even hearing it, just before falling asleep I turn over with a 'fresh' ear and it's blaring. If I roll back over it will be noticeable, but quiet again. Waking hours my ears are fine, no worries. Is this some weird sleep induced brain shut-down going on?


texts: How to correlate CNV with transcriptomic data?

texts: I have a list of differentially expressed genes. I want to correlate these genes with CNVs. I have downloaded the data from both TCGA and FireBrowse. But I am not able to understand how to do the correlation? How should I analyze the CNV data. Do you have to do some processing to get a list of CNVs with a score or something to do the correlation? Please help


texts: How does genetical variability works on bacteria?

texts:
I'm very Lay in biology, but I was studying the subject and the following problem emerged:

It's known that all bacteria are unicellular beings, and their reproduction it's asexual. Besides of that the indiscriminate use of antibiotics leads to the development of more severe infections, because of a process of natural selection and survival of the most resistant. How do we explain this process considering that asexual reproduction doesn't generate genetic variability, besides mutation? Why do we have this differences, if asexual reproduction generates clones?


texts: Dominance and recessive relationship of alleles

texts:
You can find easily in textbooks that definitions for dominant and recessive alleles as follows:

Dominant allele: produces working protein and shows its effects in hybrid state.

Recessive allele: produces defective protein and remains suppressed in hybrid state.

But I have these confusion:

Defectiveness or benefit is relative thing.
There are many genetic diseases which are caused by dominant genes, for example short toe fingers. The protein related to it is also defective.

Another definition includes dominant as wild type most circulated while recessive as mutant allele. But even this seems to be unsatisfactory as every mutation cannot be recessive or defective.

Then, finally, what determines dominance of an allele over others?


texts: Why do feces vary in color so much less than the food they are results of? E.g. you may eat food of all kinds of different colors but the resulting feces will almost always be some shade of brown.


texts: Insect identification - Possible grasshopper or grass beetle

texts: We found a small insect on our window and we cannot decide whether it is a type of grasshopper or grass beetle. It doesn't seem to want to fly, but was on a first floor bedroom window, and walks slowly and has a strong grip on the window and petri dish. We live on the outskirts of a town in Essex, UK and it could have come from a field, but they are on the other side of the house. It is a small brown insect (the main body is approximately 2cm long) with 6 legs, and the back 2 legs seem to bigger than the others.


texts: (Reference request) Formal abstract theory of evolution?

texts:
EDIT: please feel free to suggest books that are the closest you can come up with to what I'm looking for, even if it doesn't exactly overlap!

I am very well acquainted with the theory of evolution as informally taught. E.g. I don’t need a book that explains the theory, or refutes popular misconceptions.

Instead, I am looking for a formal theory of evolution as a process, and I am not specifically interested in the biological aspect of evolution, but in evolution as a more generally occuring process.

How do we formally state the different assumptions of Darwinian evolution? (Random change, heritability, natural selection).
What happens if we change these different assumptions? (Non-random mutation? Maybe, selection criteria that are influenced by the mutations, rather than independent of it)
Are there quantitatively different results of evolution based on these assumptions?
Something I find very interesting: What kind of non-biological evolutionary processes can we describe formally? E.g. evolution based on some form of non-random mutation, or based on different types of heritability. What are the different implications of different formal assumptions. How do these differences apply to different evolutionary systems? (E.g. evolution of ideas, cultures, computer viruses, evolutionary algorithms).

In summary, I am looking for a book that introduces in a very abstract way the properties of evolutionary systems (does not have to be focused on biological evolution. I’m interested in the formal properties of such systems).

NOTE: I am NOT asking about a book on modelling highly specific processes that apply to specific biological systems, such as population dynamics of preditor-prey relations. I’m interested in general, abstract theoretical analysis of the notion of an evolutionary process in general.


texts: How can a good SD / Kozak sequence enhance translation efficiency?

texts:
In prokaryotes, if there is an mRNA with a good (almost the consensus sequence) Shine-Dalgarno (SD) sequence, ribosome proteins will bind to it.
In eukaryotes, ribosome binds to the 5' cap, then start sliding until it finds a good Kozak sequence and translation initiates.

Why will a good sequence (SD & Kozak) greatly enhance translation efficiency in both cases?  I can't understand this since translation is about the bases downstream of those sequences, I have no idea how they can exert effects on overall efficiency.

in eukaryotes, how can ribosome 'foresee' which is the best Kozak in a mRNA? E.g. there are 2 'AUG' in that mRNA and the first one has a better Kozak consensus. So how can ribosome 'know' the second Kozak is worse than the first, and start translation at first 'AUG', but not continue sliding towards the second Kozak?

Thanks


texts: Are bears related to dogs in a similar way to how cats are related to 'panthers'?

texts: I've tried searching on Wikipedia but I couldn't find what family dogs belonged to. Ursidae is 'bears' and Canis is 'dogs' ; Panthera is big cats like:- tigers and jaguars is what I know.


texts: Why are segments/parasegments in fruit fly embryos staggered?

texts:
I'm reading my developmental biology textbook and I don't understand this concept. I can see how concentrations of Eve and Ftz determine each parasegment. However, I don't understand why the length of one parasegment isn't equal to the length of one segment on the actual embryo. Parasegments and segments are staggered from eachother.

Could anyone clarify?

Edit: I've gone back and re-read a bit. Is this staggering because parasegments are established while the embryo is still syncytial? So parasements are established, and afterwards cell division begins. But the daughter cells cant line up perfectly with the parasegments so segments and parasegments end up a bit staggered.

Edit2: Bit more reading. I think I got it. After parasegment establishment by Ftz/Eve, further segment polarity genes Engrailed and Wingless are expressed, with Engrailed expression being induced by either eve/ftz. The posterior side of the first engrailed cell determines where the boundary for a segment will be determined.

Can anyone confirm?


texts: Exhaustion of skeletal muscle and ligaments

texts:
I read somewhere that while doing lifting back should be straight(means normal curve), so that erectors muscle in back do the work but it gets tired easily. Hence we form curve on our back like when we sit on chair our back curves and this curve put stress on ligaments of spine which is harmful.
 Since ligaments dont get tired we feel curved back as easier. Does ligament have any mechanism ti get tired like lactic acid in muscles?


texts: What made *silphium* difficult to domesticate?

texts:
I tried this question at Worldbuilding SE, and was told that perhaps this place would give me a better chance at an answer. So, leaving aside the worldbuilding aspects of the issue, I am interested in the now-extinct plant called silphium, which was widely used as a contraceptive in the Classic world, and was overharvested into extinction at the beggining of the Middle Age, being apparently non-domesticable.

So, why exactly was it non-domesticable? Was it actually non-domesticable, or its domestication, like that of strawberries, just depended on some techonolgical innovation that was not available at the time it become extinct? If it was really impossible to domesticate, what measures could be taken, in a pre-industrial society, barring it not being used as contraceptive, to at least protect it from extinction?

More generally, what factors lead a plant to being non-domesticable?


texts: Is there a place or tool from which I can find or generate genome data for epistasis detection?

texts:
I am busy researching a school project for my honors in Electrical Engineering. The project is to create a deep neural network to detect epistasis. I have very little knowledge in the bioinformatics field and while I have managed to pick up most of the theory on epistasis and all of the new terminology, I still lack knowledge of the resources that are available to someone in my position.

I will be needing a large amount of data to train my neural network. I do not mind what form the data is in I just need many examples of epistasis. Where can I find high quality, easily accessible data for this kind? Or alternatively, what tools can I use to generate this kind of data?


texts: How do CO₂ and carbonic acid (H₂CO₃) work in buffering the blood?

texts:
Been struggling with this for the past few days even after reading half of the acid base tutorial here, if someone could help me that'd be great.

What I don't understand is how HCO3- is supposed to buffer the blood. I know that HCO3- is a base and can accept H+, but the way that the HCO3- came to fruition is by donating a H+ to the surrounding water, so there's a net zero change in H+ thus no buffering action took place. Let's say a HCO3- accepts a H+, now the CO2 produced by H2CO3 → CO2 + H2O leaves the blood because the PvenousCO2 gets higher than the CO2 pressure in the air in the lungs, and you exhale. Now you're in the exact same situation as before the CO2 got attached to H2O.
Still the text calls it as an buffer, with a very large buffering capacity as well. How does this work?

To me it seems that buffering blood using HCO3- makes as much sense as using HCl, Cl - can accept H+, right? Nevermind that HCl is a very strong acid.. Surely no one would think of using HCl to buffer blood.


texts: Is the term 'allele' specific to sexual populations?

texts:
I had always thought that 'allele' simply meant a variant of a gene and thus could be used in the context of either asexual or sexual populations. With it only being slightly less useful as a concept in asex because of the lack of recombination and thus no reshuffling of allele among offspring. Recently, I was reading a paper that wrote:

  In the asexual and sexual populations mentioned earlier, the implicit model space is simply a point in genotype frequency space or allele frequency space, respectively.

Suggesting that alleles should primarily be used in the context of sexual populations. Wikipedia gives a general definition consistent with both asex and sex use, but all examples listed are sexual.

Hence my terminology question:

Should I use the word 'allele' for variants of genes only in the case of sexual populations? Or is it alright to use 'allele' in populations of obligate asexuals?

I realize why recombination forces us to represent a whole population as allelic frequency instead of talking about individual genotypes, and why asex lets us focus on just the latter. In this question, I am not curious about this distinction, just the purely terminological question.


texts: Does GFAJ-1 use Adenosine triarsenate as its energy currency?

texts: Regarding the bacteria found in Mono Lake, CA that scientists believe uses or can use arsenic in its DNA backbone where life as we know it uses phosphorus (according to their experiments depriving the microbes of phosphorus and providing much arsenic), have researchers conjectured and tested whether the energy currency molecule used is also arsenic-based instead of ATP?


texts: Genotype to phenotype map and the G-matrix

texts:
Suppose I have a genotype-phenotype map defined by the matrix $\mathbf{Z}$:

The scalars $G,P$ represent the number of genotypes and traits, respectively. The map assigns a set of phenotypic traits (the columns) to a set of genotypes (the rows), where $z_{ij}$ is the quantitative measure of an individual of genotype $i$ with respect to a trait $j$. I want to know how the average value of each of the phenotypic traits changes over time, suggesting I should use quantitative genetics theory and formulate the equation

$\Delta \bar{\boldsymbol{z}} = \mathbf{G}\mathbf{P}^{-1}\mathbf{s}$,

where, $\mathbf{G}$ is the additive genetic variance covariance matrix, $\mathbf{P}$ is the phenotypic variance covariance matrix, and $\mathbf{s}$ is a vector of covariances of each trait with fitness. Assume that I know the frequencies of the different genotypes in the population.

Question 1 Can I formulate the additive genetic variance-covariance matrix from the genotype-phenotype map alone (and pop freq)? Note, I don't know anything about the underlying genetic model - number of loci representing each genotype, dominance structure, epistatic interactions, etc.

Question 2 If I assume the genotypes represent haploid individuals, does this change things? Is the additive genetic variance always equal to the phenotypic variance (assuming no environmental effects) in a haploid model? In other words does $\mathbf{G}\mathbf{P}^{-1} = \mathbf{I}$? What I'm thinking is that epistatic variance might affect things, but it shouldn't affect heritability in a haploid model, which is what $\mathbf{G}\mathbf{P}^{-1}$ is a measure of.


texts: How does the introduction of clones would affect population genetics?

texts: Since the ability to clone animals gives another way to preserve species, this could help for the breeding process. It has been noted that with the ability to clone animals, endangered species can have their population numbers increased in a short time. How would this impact these population from the perspective of genetics/ the gene pool?


texts: How to isolate a high proportion of available helminth ova from animal faeces/feces without damaging them?

texts:
I need to isolate large numbers (tens to hundreds of thousands) of cat (and later dog) hookworm ova from cat/dog faeces.

I have a centrifuge, and various sieves with pore sizes of 20, 63, 75, 106, 125, and 180 microns as well as the ability to create various flotation solutions to any specific gravity

The specific gravity of the ova is 1.21 and they are oblong, their size is 50 by 38 microns varying by ±5 microns.

I have tried sieving the cat faeces after emulsifying them using a liquidiser. I pass them through successively smaller pore size sieves but the concentrated ova still contains a very large admixture of unwanted faecal material.

Flotation following sieving by bracketing the ova in successive flotations of iron sulphate results in too much contamination and many ova are lost.

My technique is self-taught and clearly lacking.

I need to remove 98-99% of the unwanted faecal material without damaging the ova, which are not very resilient.

My access to equipment any more sophisticated than that listed is unlikely but if costing less than a thousand pounds possible.

I am new to this area, so I am sorry if I have omitted anything required or failed to follow form and protocol.

Thank you very much in advance.


texts: For people who work in microbiology labs, what software do you use to manage your strains?

texts:
It's just a small microbiology lab that currently records everything on paper, and there's quite few mutants as well. Is Excel commonly used for this sort of thing? Or is there a better software to manage a lab?

Thanks for any help


texts:
I'm currently studying for the MCATs. After doing some biochemistry practice questions, I came upon a question that I believe may be incorrectly posed. I was wondering if I'm correct in saying this or not.

The question is: " A certain cooperative enzyme has four subunits, two of which are bound to substrate. Which of the following statements can be made?"

The correct answer is "The affinity of the enzyme for the substrate is greater than with one substrate bound."

My confusion lies in the fact that the question never specified whether this cooperative enzyme had a positive or negative Hill coefficient. When approaching future questions like this, should I assume a positive Hill coefficient?


texts: Can humans ever directly see a few photons at a time? Can a human see a single photon?

texts:
I am not asking the following question: Can humans ever see a photon in the same way we see a chair?

My question is: Can a human retina respond to a single photon? If so, how does this happen and why is the retina able to "sense" (detect) a single photon?


texts: Umbrella term for agonist, antagonist, inverse antagonist, etc.

texts:
For most receptors there exist different ligands that induce different responses. Depending on the response these different ligands can be classified into different groups such as agonists, antagonists, inverse antagonist, etc.

My question: is there a term that summarizes all of these different concepts?

I'm looking to express something like the following: 'addition of a methyl group to the phenyl ring changed its X from agonist to antagonist.'


texts: Using egg whites as DNA destruction test possible?

texts: My current theory to test for the destruction of any DNA that may be used as forensic evidence is to use an egg white. I would like to test various myths and methods for destroying DNA evidence and need a sure-fire method of testing whether or not the DNA is destroyed. The reasoning behind the egg white is because when you cook one or expose it to strong acids or bases, it turns white. Indicating the denaturing of the proteins within the whites. Would this work to test for the denaturing of DNA molecules to? Several experiments would be conducted with each method, using egg whites to determine whether or not the DNA would be destroyed. Would egg whites, with great accuracy, determine whether or not the sample can be identified. If not, could you please suggest another alternative?


texts:
I found this statement in my study materials in the section of Staphylococcus

  The AG structure:

  protein AG (species specific);
  polysaccharide AG (serotype specific).

I know what is Protein A/G, a recombinant fusion protein that combines IgG binding domains of both Protein A and Protein G.

What is the point of this AG structure thing in the contex of Staphylococcus?
Can we say that staphylococcus have AG structure?
I think it has properties related to protein A\G and also to polysaccharide A\G.
I know very little about polysaccharide A\G and not sure how it is related to serotype specificity in the context of staphylococcus.

Extension to the question

Antigenic structure of Steptococcus pyogenes:
the group AG is unique, placing streptococcus in group A.

What is the AG here?


texts: How can omnivores be in more than one trophic level?

texts: I'm learning about the ecosystem and its relation to organisms, So organisms in a food chain can be put from producers to tertiary organisms. I just don't get the part where an organism can be labeled into 2 trophic levels ? how is it placed in the pyramid if so ?


texts: Can we investigate the cell biology of extinct microorganisms?

texts: I know that there are microfossils, but not if we can we know about the organelles, genetics or macromolecules of the cells that left them behind.


texts: Reading an amino acid physicochemical properties diagram

texts:
I want to know if I am reading the venn diagram correctly and why there are discrepancies in the diagrams.

I'm trying to determine which amino acids are considered hydrophobic and I am using this diagram suggested by my teacher from Amino acid properties and consequences of subsitutions.

From the diagram I've determined that A, G, C, T, V, I, L, F, W, Y, H, K, M are hydrophobic.

My problem is when I visit other sources I do not get the same results. Using Amino Acid Table I determines that A, G, I, L, M, F, P, W, Y, V were hydrophobic:

Furthermore, there is even another different venn diagram from Decoding the Building Blocks of Life from the Perspective of Quantum Information


texts: Do the effect of inbreeding depression disappear after the first generation of outbreeding?

texts:
An animal that is the result of generations of inbreeding tends to have lower fitness. (More diseases etc.) This is usually explained by harmful but recessive mutations that exist in all populations, but in inbred animals end up occuring on both copies of a gene in a chromosome-pair.

If the problem of inbreeding is that the two sets of genes in the chromosome pairs are too alike, does that imply that the offspring of an inbred animal will revert to "normal" fitness as long as the inbred parent was mated with an unrelated animal? Seeing as the inbred parent can only transmit one copy.
Or is the situation more subtle?


texts: What do we call these containers used in biotechnology?

texts:
I'm translating an autoclave instruction from Russian, and it says that these containers (ванночки) (see the black circle on the below photo) are to be sterilized in the autoclave. I'm not sure what they are called in English-language biotech texts.

The Russian text uses the vague term "ванночки", literally "little bathtubs". Maybe just "containers"?


texts: Is the oxygen exhaled by plants during the day compensated by inhalation of carbon dioxide at night?


texts: Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

texts:
Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am obviously not talking about the microscopic uses of metal, as in human blood etc.

Why are there no plants with metal thorns? No trees with "reinforced" wood? No metal-plated sloths? No beetles with metal-tipped drills? Or are there?

I can think of some potential factors why there are none (or few), but I do not know whether they are true:

Is metal too scarce near the surface?
Are there certain chemical properties that make metal hard to extract and accumulate in larger quantities?
Is metal too heavy to carry around, even in a thin layer or mesh or tip?
Can metal of high (tensile etc.) strength only be forged under temperatures too high to sustain inside (or touching) organic tissue, and is crystallised metal too weak?
Are functionally comparable organic materials like horn, bone, wood, etc. in fact better at their tasks than metal, and do we humans only use metal because we are not good enough at using e.g. horn to make armour or chitin to make drills?

As a predator, I would like to eat a lot of vertebrates and save up the metal from their blood to reinforce my fangs...

A bonus question: are there any organisms that use the high electric conductivity of metal? Animals depend upon electric signals for their nervous system, but I do not think nerves contain much metal. The same applies to the few animals that use electricity as a weapon.


texts: I photographed a couple of butterflies and birds in Argentina but can't identify them. What are my options?

texts:
I photographed a couple of birds and butterflies in Argentina and tried to identify them. I tried online species identification tools, looked in books, and just tried to find pictures on Google with similar animals. This worked for some of the pictures, but for others I couldn't find the correct species. So as a layman, what options do I have?
Here are the ones that I couldn't identify so far
1 (There seems to be a bird and a beetle in this picture. The bird could be a Thraupis Episcopus)

2 (A hummingbird but which one?)

3 (Seems to be the same hummingbird)

4 (No idea)

5 (No idea)

6 (No idea)

7 (No idea)

8 (No idea)


texts: How different can the Tm be between 2 primers?

texts:
I have a forward primer with Tm 85 degree Celcius. I cannot change this primer. But I have two options for the reverse primer. One with Tm 65 degree Celcius (Annealing at 65 degree Celcius) and another with 72 degree Celcius (Annealing at 72 degree Celcius).
First of all, will either of the primers work for me?
If so, which pair would be better?


texts: When Dendritic cell travels to nearby lymph node with antigen presented on MHC II molecule, the helper T-cell residing there gets activated. But what happens to B- cell residing there? Does it get activated too when helper T-cell is activated and start producing antibodies for that specific antigen?


texts: How do PLINK files and HapMap Phased files differ?

texts: I know that PLINK and HapMap files show the same information, but can you give a thorough explanation of how exactly they differ.


texts:
How long does it take for the Opioids listed in the Description to induce Analgesia when Administered via IV? Now I don't mean how long it takes for euphoria to come on but analgesia.

The opioids I would like to know this information to include:

Buprenorphine
Butorphanol
Fentanyl
Hydromorphone
Methadone
Morphine
Oxycodone
Pentazocine
Pethidine (meperidine)
Sufentanil
Tramadol


texts: Do stem cells have an apoptosis mechanism and , if they do could this be used to repair the  cell self-destruction pathways in a cancer cell?


texts: Is it possible to temporarily paralyze someone through the use of electric signals or focused ultrasound?

texts: I've been reading about how it is possible to send signals to the brain using focused ultrasound or electrical impulses. It is possible to make someone see a certain shape or color by stimulating different areas of the brain. I was wondering whether or not it would be possible to temporarily shut off a person's motor functions by for example, sending signals to the cerebellum or perhaps intercepting them before they can travel down the spinal chord.


texts:
I was reading an article in nature communications, when I came across this sentence: "The ‘match’ rule was indicated by either a blue circle or a auditory upward sweep".So I tried googling what was an upward sweep, and came across this: "natural and complex vocalizations consist of basic elements such as upward sweeps, downward sweeps, constant frequency components, amplitude modulations..." I don't understand this. Can someone explain what is an upward sweep?

Here is the link to the article: http://www.nature.com/ncomms/2013/131128/ncomms3878/abs/ncomms3878.html,

But I think you have to pay to view the whole article, so here is another link that discusses the findings of the article:

http://www.uni-tuebingen.de/en/landingpage/newsfullview-landingpage/article/von-wegen-spatzenhirn-wie-nervenzellen-schlaues-verhalten-bei-rabenvoegeln-ermoeglichen.html


texts: Would it be possible to create a gel, holding viruses, that could alter the human genome when rubbed in?

texts:
I was wondering if it could be possible to engineer a virus, that when it comes into contact with human hair follicles, it could alter someones natural hair color.
Naturally blue hair anyone?

Doubtless there are loads of problems, but i was hoping they could be identified and potentially worked around.


texts: Antigen Antibody reactions during blood donation

texts:
A person wih blood group O is called a Universal Donor. Well, his plasma contains antibodies A and B. During blood donation, if blood group O is given to a person with blood group A (since blood group O can be donated to all the blood groups) then wouldn't the antibodies of the donor with blood group O harm the recipient?
Although nowadays doctors prefer giving blood having 100 percent compatibility...


texts: Cosmid genomic library, or genomic cosmid library?

texts: Which usage is better for referring to a "cosmid library of genomic DNA fragments"?


texts: Detecting Calcified stones and cracks in tooth

texts:
I had a dental problem when my first molar broke some months ago and after some decay and pain I am undergoing a dental treatment. The doctor was performing a root canal and kept on talking about calcified stones being formed and looking for a 'tak' sound inspite of having x-rays. Doctor did not point to the calcified stones earlier and suddenly came out with this new issue. In the mean time when looking for stones doctor actually managed to break my tooth and has blamed grinding and clenching for a crack that caused the tooth to break.

I am shocked that neither the calcified stone nor the crack showed up in x-ray and the preliminary examination. With current technology, can the cracks in tooth and calcified stones not be detected.


texts: Identifying an insect looking like a crumle

texts:
Recently a little insect crawled over the carpet. First I did not notice, as its appearance is quite similar to the coloring of the carpet. Then I understood that it is not a rolling crumble, as the window and the door were closed.

I took it on an ordinary sheet of DIN A4 paper, but have not the slightest idea, what kind of insect it is. It makes the impression to have taken a shower of water and dust in a row.

What's that insect called?

The second photo gives an idea of the size, as it shows a drinking glass turned upside down.

Note: The place this insect was encountered is in eastern Germany


texts: Am I entitled to the latlong coordinates of all specimens used in a species revision paper?

texts:
If someone publishes a species revision with distribution maps but without publishing all the data used in the paper itself - or in an attached or linked-to  file - are the authors nevertheless required to make all the data necessary to the paper publicly available on request?

I'm assuming they are as this makes sense from an accountability & replicability perspective (and nonsense of the idea of "publication" otherwise?) - but it's not clear to me from searching online.

Thank you!


texts:
Hypothetical question regarding three animals 'species' {A, B, C}.

Are there any examples in nature where {A and B} cannot regularly produce viable offspring, however {A and C} and {B and C} can regularly produce viable offspring.

I imagine that such a situation could arise if {A, B, C} have a common ancestor, but {A and B} are sufficiently different from each other, but not from C.


texts: My textbook says "As the seed matures it loses water and enter dormancy". I am confused as to whether this happens before the seeds are transported or after, and as to how seeds know to become dormant when required and then become active again.


texts: How much energy does a cell expend maintaining its contents?

texts:
In software engineering, an analogy is sometimes made using biological cells. I would like to know whether it has basis in fact.

People say (Alan Kay was first) that "objects" in software should be like cells: separate from one another, communicating by passing messages. This separateness has been argued by saying that a cell spends much of its metabolic energy keeping its insides in and its outsides out. The implication is that programmers should likewise spend significant effort maintaining boundaries between parts of a system.

Is this actually true? What percentage of its energy does a cell generally spend maintaining its contents?

(My guess is that the answer varies wildly depending on the cell and its environment, but some ballpark example numbers would be nice.)