texts: How does the cell regulate different metabolic pathways?

texts:
I heard somewhere that cells use different nucleosides bound to triphosphates e.g. ATP, GTP, CTP and other modified compounds: NADH, NADPH to distinguish between different metabolic pathways and so they regulate where they use up the energy. I heard that kinases play an important role in the regulation. Is there a connection (I guess there is if I check NADPH)? Is this regulation mapped? I mean is there a simple map which contains the main processes and the energy carrier and regulatory compounds?

I am looking for something like this map (of receptor responses), but for metabolic regulation:

Figure 1 - signal transduction - wikipedia

So it possibly contains mitochondria, O2, CO2, flows, ATP, NADPH, etc... I understand that different cell types can have different energy producer and consumer organelles and it is not possible to create something that is universally true, so I would be satisfied with a map of your favorite human cell type.


texts: Could the Warburg effect be used to starve cancer cells in situ?

texts:
What is wrong with the following chain of reasoning?

Nearly all cancer cells rely on high rates of glucose uptake (upto 200 times more than normal cells). This is known as the the Warburg effect.
There is only one cell type in the human body that is obligated to use glucose - red blood cells (erythrocytes).
Starve cancer cells of their only energy source by inducing hypoglycaemia in the patient, preserving red blood cells using, for example, erythrocytapheresis or an oxygen-carrying substitute.

I understand that to completely eliminate a tumour such a regime would need to be in place for an extended period, but would like to know why such a treatment isn't feasible in theory?


texts: What kind of "size" does SDS-PAGE separate by?

texts:
What is the exact property of the protein that affects migration of bands in SDS-PAGE; is it length, volume, or mass?

For example, will GGGGGGGGGG (glycine 10-mer; mw <600) migrate more or less than WWWWW (tryptophan 5-mer; mw >900)?


texts: What causes the overactivity of keratin production and expression in the cells of the nail bed/ nail matrix after some traumata?

texts: What is the cellular mechanism of traumatic(sterile) onychodystrophy(hypertrophy)? I.e one hits his toenail and has it removed twice( once after the first trauma and then again 3 years after the first removal) by a surgeon, because it got crooked and grows back dystrophic(extremely thick and dark) without any signs of infection.


texts: Why isn’t Haemoglobin a plasma protein, rather than being encompassed by the erythrocyte?

texts:
Erythrocytes (red blood cells) are a common feature of almost all vertebrates. What evolutionary advantage do they provide in containing haemoglobin, rather than it being just a plasma protein? In fact, haemoglobin is dissolved in plasma in a few annelids and haemocyanin in cephalopods.

The only reason I can think of is that haemoglobin is small enough to get filtered into the tubules of the kidney and is renotoxic. Maybe that's why it had to be packaged into erythrocytes. But isn't this a greater cost than reducing the pore size to prevent it being filtered out? Also, doesn't haemoglobin or haemocyanin get filtered into the primitive kidneys of annelids and cephalopods?


texts: Claim: Cat litter with different colors each son, could have different fathers

texts:
I'm newbie in biology. I can't look this in the internet and distinguish reliable sources because of this. I want to know if it's normal that a cat mother litter normally has multiple fathers, and that is the cause of cats looking very differently colored. Now, I imagine difference in coloring of the fur could happen with the same father, because sons are not necessarily genetically identical, however there are many claims in google when searching:

http://pets.thenest.com/can-cats-litter-two-different-fathers-8341.html
http://pets.thenest.com/possible-kittens-one-father-8061.html
http://www.drjeffnichol.com/?p=2277
http://animalcarebasics.com/each-kitten-different-father/

If the claim is true, does all the kids start developing at different starting times? Does that mean they could be born some more premature than others? How big is the window for female cats to be fecundated?


texts:
UACC-462 is a pancreatic cell line established in the University of Arizona Cancer Center (UACC).
The cells are available from ATCC and there is the instruction for culturing UACC-462.

M-41 medium. The base medium for this cell line is ATCC-formulated Leibovitz's
L-15 Medium, Catalog No. 30-2008. To make the complete growth medium, add the following components to the base medium (final conc.):

fetal bovine serum to a final concentration of 5%

0.01 mg/ml transferrin

0.01 mg/ml insulin

5 µg/ml (55 U/ml) catalase

3.6 µg/ml (0.01 mM) hydrocortisone

10 ng/ml EGF

3 ng/ml Estradiol

70 µg/ml O-phosphorylethanilamine

0.0008 µg/ml L-thyroxine

extra 2mM L-glutamine

Atmosphere: air, 95%; carbon dioxide (CO2), 5%.
Temperature: 37°C

On the other hand, L-15 is designed to culture without CO2 and often used time-laps experiments under microscope.

My question is why L-15 based media can be used in CO2 incubator. Is the cell line acid-philic?


texts: Alignment of sequenced fragments in Next Generation sequencing (sequence assembly)

texts: The NGS (Next Generation Sequencing) involves fragmenting the DNA to be sequenced. This is followed by attachment to beads or flow cells and then a localized PCR is conducted. Modified bases are added and with addition of each base, a detection is made (by fluorescence for instance) for the type of base bonded. After complete sequencing of all the fragments, how are these reads of fragments assembled in the way they were in the original non-fragmented DNA? (in short: How sequence assembly works?)


texts: Could a biological process organically build solid metal "organs"?

texts: Human ingenuity has made great use of metal tools. But are there any known, or potential, biological processes that might produce sizable solid metal objects like how for example skeletons and shells are being grown? Does solid metal manufacturing require melting point temperatures beyond what biological processes can survive, or could it be grown by proteins more or less atom by atom?


texts:
This is a voltage clamp on an ion channel. When the voltage is stopped there is a still a current at the end (the tail current). I understand that the gates aren't completely closed because of which there is still some current flowing.

What I don't understand is that why does the current suddenly jump to a small value? Shouldn't it gradually go down?


texts: How are chemical reactions organized in prokaryotic and eukaryotic cells?

texts:
I realized I only have a vague understanding based on what remember from high school and I don't know if they ever really broke it down for us but:

In general how do both prokaryotic and eukaryotic cells organize their chemical reactions? In prokaryotic cells I thought there were no organelles so does that mean that every reaction depends on the diffusion of the reactants throughout the cell and that any reaction could happen anywhere in the cell? And in eukaryotic cells, are organelles always used to compartmentalize stages in chemical synthesis?

What I'm getting at is that if everything is just floating around freely within a cell, wouldn't a lot of reactions interfere with each other? I'm wondering how these two types of cells approach this problem.


texts: Identification of unknown bagworm (Singapore)

texts:
This bagworm was found in Singapore (near McRitchie Reservoir) some time in June 2012.

This is the plant from which the bagworms were obtained:

A few examples of the bagworms:

The bagworm when dissected out of its bag:


texts:
Many organs can be transplanted nowadays, including the liver, lungs and kidneys.

Can the brain be transplanted?


texts: Cut-off values for LD, LOD and D-prime as algorithmic input

texts:
I created an algorithm to generate SNPs for random people of different descents - based on HapMap data. While this works good, there is something else I want to take into consideration. So if a SNP has a MAF of 0.01, with an LD of 1, the generated results will, in most cases be sufficient. This is not the case for a MAF of 0.4 and LD of 0.8.

The HapMap LD files have, besides the LD data, also LOD and D-prime. The question is, is there a set of parameters so that as much of the relevant LDs are filtered out of the total set?

I want to filter this out, since, for example, there are LDs described with a value of 0, or an LOD < 1, and problematic D-primes.

Trying to rephrase the question:

Given a huge set of LD information (250GB), which are not filtered on statistical power, I want to make a subselection of LD information that are 'relatively' descriptive of the link with respect to another SNP. So I need to have a set of parameters to filter the LD information from HapMap. Of which possible values are LD, LOD, and D-prime.

Eyeballing the LD dataset, it doesn't gives a good instinctive boundary. A problem with using the data as is, is that both the D' as LOD can be both high and low. I know the parameters have an interdependence, but not a one-to-one mapping.

Does anybody have experience in filtering non-descriptive LD values from (for instance) the HapMap LD dataset?


texts: Are bacteria necessary for an individual's life, or, how long could a person live without bacteria?

texts:
Bacteria are essential to life in that they are responsible for breakdown of organic substances, etc. but are bacteria necessary for an individual's life?

In other words, how long would a human survive if they took a super-antibiotic which killed all the bacteria in their body, with the current state of medical technology? If they died what would be the most likely cause of death?

Assume bacteria don't recolonize your body.

Background: I call bacteria the "Lords of the Earth" both to remind myself to be humble and (rather more) as a conversation-starter. I'd like to be able to underline their importance in the ensuing discussions.


texts:
How can everyone have unique iris and fingerprints? After a certain amount of human beings have lived on earth, wouldn't it be possible to exhaust all possible combinations?

The same principle applies to DNA. Lets say counting all the nucleotides on a strand of DNA we find that there are a total of $N$. We know there are 4 types of nucleotides, thus the total number of possible DNA sequences equals $4^N$. This is exponential, and since $N$ is immensely huge, $4^N$ will be unthinkably huge as well. However, since $4^N$ is a finite number, how can DNA be guaranteed to be unique? Doesn't that contradict the pigeon hole principle?


texts: What percentage of a cell's volume is occupied by protein?

texts:
I was looking at one of David Goodsell's illustrations of a cell:

And it seems to suggest a very crowded picture of the intracellular environment. Just how crowded are cytoplasms? What percentage of the volume is typically taken up by protein, water, and other major species?


texts: Exercise vs stimulants, which is more effective for promoting concentration?

texts:
Stimulants are the first choice for treating ADHD. But we also know that exercise helps to improve concentration.

We know that both stimulants and exercise increase bloodflow to muscles and to the brain by activating the sympathetic nervous system. Is this is the MAIN cause of the effect of improved concentration, rather than, say, specific activation of parts of the brain responsible for learning or planning or something similar?

What I'm asking is, do drugs and exercise have different effects on the brain, what are the differences, and what are the consequences of these differences on concentration and learning? Which is more effective for promoting concentration and why?


texts: What happens during fixation of Nucleic acids on nylon membrane

texts:
In Southern blotting technique, fixation of DNA to nylon membrane is a step prior to hybridisation with probe. It is done by baking at 80ºC and according to this cross linking between DNA and nylon takes place.

What I am unable to understand is, if there is cross linking between DNA and nylon then, how does the probe bind complimentarily to the DNA? Isn't cross linking may mask the sites which may form hydrogen bonds?


texts: Book/source for learning bioinformatics, focused on genomics?

texts: Does anyone know of sources for learning bioinformatics, focused on genomics? I would like to learn alot of skills I could apply potently in the workforce if I ever became adept at the fields. My computer science knowledge is weak, and my biology knowledge is mediocre, but i find the topics to be interesting. I have read "The dynamic Genome, A Darwinian Approach, by Fontdevila, and it was a bit rough for me. I have also read some of a introduction to genomics textbook, by Arthur M Lesk, and found it to be very "Academic".


texts: Modelling how much cadmium a cell will be able to chelate with phytochelatins

texts: I am involved in a synthetic biology project where I have to do modelling with ODEs. The biological process I want to model is the chelation of Cd2+ with phytochelatins, to know how much can be chelated. I know the basics of ODEs and I already did other modelling tasks, but I never studied anything related to chelation (I am a computer scientist) so any hint about how these kind of biochemical reactions are modelled would be helpful to get started.


texts: What are the differences between insects and spiders?

texts:
I have always been told that a spider is not an insect, since the former has 8 legs and the latter 6 legs.

Is it just a matter of definition and spiders could have been defined as "8-legged insects"? Or are there more fundamental differences between the two kinds of animals and the distinction makes sense from the viewpoint of biology and evolution?


texts:
When I try to rotate my eye, both of my eyes will rotate the same amount and in the same direction (obviously).

I'm wondering if it is possible to control each eye separately. I've never seen anyone that can do this (except some pics on the internet which I'm not sure if they are digital edits simply for fun).

Is it possible? If not, why? Is it because they are both controlled by the same nerve? Or is it simply because we are not used to it and it's super difficult (but possible)?


texts: Can protein structure be determined by X-Ray Diffraction in a single image?

texts:
I'm reading about the use of x-ray crystallography to determine protein structure. According to my book, data is collected at 30-360 angles (dependent on the symmetry of the protein). An illustration is given with concentric rings labelled with distances - the further out the points are, the higher the resolution.

Is the image a composite (where the angle of the point point from the centre is equivalent to the angle of the reading) or is a separate image taken at each angle? Are there any other reasons why more images would be required?

Thanks.


texts: Plant's phylogeny tree to identify which of them are closer (genetically) with another plant

texts:
I'am trying to create a phylogeny tree from some plants, as the post's title says, to help me conclude which of those plants are closer genetically with another one plant.

So let's say that this is the plant list:

Nicotiana tabacum , Zea mays, Oryza sativa, Solanum lycopersicum,    Solanum tuberosum, Erythranthe guttata, Hordeum vulgare, Vitis vinifera, Prunus persica, Glycine max, Populus trichocarpa, Medicago truncatula, Phaseolus vulgaris, Morus notabilis, Citrus clementina, Setaria italica, Theobroma cacao, Acacia mangium, Cicer arietinum, Triticum urartu, Brachypodium distachyon, Aegilops tauschii, Panax ginseng

and i want to see which of those species is closer with Sorghum bicolor.

Is there any easy way to conclude something like that or it needs to get results out of bioinformatics using a specific gene , align it , and then see the tree ?


texts: How many people are required to maintain genetic diversity?

texts:
Imagine humans were to colonize a distant planet and it was a single one-way trip. How many people would they need to bring?

Obviously 2 is the minimum, but that would result in a lot of inbreeding.

So what number is the minimum number of people you can have in an isolated community and still maintain a healthy diversity?


texts: Why does a "cascade" of events happen during signal transduction?

texts:
I've been watching some videos on signal transduction and it says that because there are enzymes being activated by the signal, then there is a "cascade" which happens afterwards...I don't understand why?

Thanks.


texts:
Since we homo sapiens (and all other species) are continuously evolving, are humans undergoing speciation based on our environment? OR has there been any difference across people that could say speciation has already happened?

PS: I am asking this question because I have recently seen a documentary in which some Chinese anthropologists claim that Chinese people are a different species altogether. Ref: Incredible human journey (Section Asia)


texts: Is it harmful for someone to consume things full of bacteria if they don't get physically sick from the bacteria at all?

texts:
Or as another example - what if you touch a surface that's contaminated with potentially pathogenic bacteria (like the ones at http://arstechnica.com/hardware/news/2008/05/study-keyboards-make-excellent-homes-for-nasty-bacteria.ars) and introduce those bacteria into your body and don't get sick. Then could there be some other damage that the bacteria could do your body? Like, at the very least, maybe promote a not-particularly-noticeable increase in inflammation in the regions where the immune system decides to fight the bacteria? Inflammation only starts to get noticeable when some really high threshold gets crossed.

By "sick", I mean, that the symptoms of the infection become noticeable enough to cross the threshold of being unpleasant to the person carrying the infection. I'm sure that there may be some sub-threshold effects that come in first.

And why is this important? We have to establish some sort of balance between using too much soap/other cleaning agents and not using enough of it. If we use too much, the bacteria could develop antibiotic resistance. And if we use too little, there could be an increase in the types of bacteria that cause chronic infections that don't get noticed, even though some of us might not even get physically sick more.


texts: Norepinephrine and epinephrine have similar stimulant properties on the nervous system and the body. I was wondering which hormone is the antagonist of epinephrine?


texts: How can cats' claw grow sharper without replacing the claw?

texts: I cut my cat's claws once a month. The claws always have pointed and sharp tip even though I had cut them last month. I assumed cats cannot change the shape of the claw by growing new keratin at the tip. Also it does not looks like the cat grow a new claw and abandon the old one every once a month or so. How is it possible that the claw grow sharper?


texts: Help me understand voltage patch clamping

texts:
Before I type my question it is important to know that I already tried looking this up on my own and could not find an answer because the answers are all in complicated physics terms and this topic is only half a page in a chapter on Action potential in my 1st year physiology textbook.
My textbook says:

This apparatus is used in the following way: The investigator decides
which voltage to establish inside the nerve fiber. The electronic
portion of the apparatus is then adjusted to the desired voltage,
automatically injecting either positive or negative electricity
through the current electrode at whatever rate is required to hold the
voltage, as measured by the voltage electrode, at the level set by the
operator. When the membrane potential is suddenly increased by this
voltage clamp from −90 millivolts to zero, the voltage-gated sodium
and potassium channels open and sodium and potassium ions begin to
pour through the channels.

1: Does that mean that the change in membrane potential that I did resulted in changes in the conformational states of ion channels which in turn changed the membrane potential that I need to control ?

To counterbalance the effect of these ion movements on the desired
setting of the intracellular voltage, electrical current is injected
automatically through the current electrode of the voltage clamp to
maintain the intracellular voltage at the required steady zero level.

2:Is this all still the step of setting the membrane potential to a certain specific value ?

To achieve this level, the current injected must be equal to but of
opposite polarity to the net current flow through the membrane
channels.

3: I'm not sure I understand this.

Finally, the investigator adjusts the concentrations of the ions to
other than normal levels both inside and outside the nerve fiber and
repeats the study.   When sodium is the only permeant ion in the
solutions inside and outside the squid axon, the voltage clamp
measures current flow only through the sodium channels. When potassium
is the only permeant ion, current flow only through the potassium
channels is measured.

4: do they make sure that the flow is only from sodium channels by setting the membrane potential to the equilibrium potential of other ions or a potential between the equilibrium potential of the other ions (so greater than it) and the equilibrium potential of Na (and also less than it )?


texts: What made this small light weight bee hive-like structure?

texts: This structure was photographed in mid December in Eastern Iowa, USA along a path within a public use area with tall grasses framed by small to medium trees.  It is approximately 5 cm (2 inches) long and 10 cm (4 inches) in diameter.  It had the light airy appearance of honeycomb but was one solid ribbed structure attached to a small branch.  I'm not sure if this was something used over the summer by an insect or if something will come out of it in the spring - winter temperatures often go below -18 degrees C (0 degrees F) in this area of the country.  Any help would be appreciated.


texts: How outdoor/wild plants survive without any proper human support?

texts:
I will take care of indoor plants because it was growing in my lawn
if I don't care then parasitic vines will destroy my plants.

But how plants take care of itself which are still surviving in forest without any human support?


texts:
West Bali, about 10 meters deep. Body is roughly 10 cm across.
Does not move.


texts:
I' ve read that some diseases result in the shrinking of neurons in the brain.

Does the axon shrink or the cell body? And what' s the underlying mechanism that shortens the axons, if that' s the case?

And is it possible that axons shrink even without any diseases?


texts: How do transplanted stem cells find their way to bone marrow?

texts: Miraculously, transplanted stem cells find their way to the bone marrow missing the stem cells. How do they achieve this?


texts: Why are there only 6 molecules of water produced in the synthesis of the fatty acid, palmitate?

texts:
The equation for biosynthesis is

1 Acetyl-CoA + 7 Malonyl-CoA + 14 NADPH + 14H+ -> Palmitate + 7 CO2 + 14 NADP+ + 8HS-CoA + 6 H2O

I really don't understand how there is only 6 H2O produced... and not 7?

Every cycle, there is the condensation of one molecule of water.

The first turn yields a 4 carbon molecules. Since palmitate is a 16C fatty acid, and two carbons are added each turn, there should be 6 turns remaining, for a total of 7 turn.

All the other numbers seem right. At first I thought my teacher could have made a mistake but everywhere I look on the net, it say 6 H2O.

Someone has an explanation for this?

Thank you :)

Edit: I found the answer in Voet & Voet yesterday. I add it here in case it can help someone else!

At the end of the biosynthesis, the palmitate is bonded with the Acyl-Carrier Protein (ACP) and it takes an hydrolysis to separate it, hence the missing H2O.


texts: Why does B12 deficiency enlarge red blood cells?

texts: I'd like to know why B12 deficiency enlarge red blood cells


texts:
Not sure where to ask this question and thought this would the best place.
I am not after any opinion or theological, philosophical answers.
I am after the science or biology research, experiments or facts.
I would like the answer to be focused on the following:
Why do we die? With the condition that there are no diseases or any outside factors contributing to death.

In a simpler way, what makes us die biologically, physiologically. Is there a trigger? Is it cellular?.... and so on

As per suggested comment, I have researched genetics such as cell regeneration dynamics, Organ's lives studies.
Yet I find very little on the brains involvement, nervous system, chemical or anything else on the multitude of systems we have including triggers or irreversible messages from any or these systems


texts: What is the difference between the evolution of fins in whales and fish?

texts:
For a homework assignment I received the following question:

Which statement best explains the evolution of fins in whales and fish?

a. The common ancestor of whales and fish possessed genes for fins.

b. Whales and fish possess the same mutations in their genomes.

c. Fins evolved in whales and fish because they both use them to swim in water.

d. Fins evolved in whales and fish because of different mutations that occurred
in their genomes.

e. Fins evolved in whales and fish because their most recent common ancestor swam in water.

My answer is (c). Of the given options, it seems most accurate. I feel that the language is unclear as many organisms who do not have fins swim in water. That can be a logic against the option. But, the given answer is (d). That seems too bizarre as even humans and fishes have different mutations in their genomes. (c) seems more appropriate as it can exemplify convergent evolution.


texts: What enzyme or bacteria could dissolve plastic?

texts:
What enzyme or bacteria could dissolve plastic aside from acetone? Preferably, low-cost and environmentally friendly. Any suggestions would be helpful.

I'm targeting for thin plastic (low-density polyethylene). Environmentally friendly for me is that it follows the EPA standards from the USA. I'm targeting for around 150 USD. I'm okay with solvents that make the plastic swell, but a chemical that could dissolve it is preferable.

I asked this on the ChemStack Exchange and I'm not sure if enzymes and bacteria are allowed there so I'm asking here too. Thank you!


texts: How much time do the different mechanisms of gene regulation need to take effect?

texts:
I am thinking of the major regulatory mechanisms, like general transcription factors, activators, repressors, and RNA interference.

If non-active regulator genes using each of the different mechanisms were activated, what would be delay (on average) between each of those genes' activation and their downstream regulatory effect?


texts: There is natural selection but there is also sexual selection which some regard as a category of natural selection.  There is also artificial selection (by humans).  The question is, what is a most appropriate for selection?  What criteria does a  force have to meet in order to be considered to have acted selectively?


texts: Why does the posterior region and the right ventricle of the heart are not well represented in standard 12 leads?

texts: When assessing an ECG we divide our 12-lead into four main contiguous lead groups: inferior, lateral, septal, and anterior. Regions not well represented on a standard 12-lead are the posterior region and the right ventricle, So if there is an infarction in these regions how we can determine it ?


texts: which exact mechanism triggers the first cell differentiation after n divisions?

texts:
I would like to understand which mechanism triggers the first cell differentiation after n divisions.

I read previous articles on SE and Wikipedia articles on cellular differentiation and embryogenesis but still fail to understand what exactly makes it so that starting from a given division cells suddenly start to be different.

Wikipedia claims that

  In the first hours after fertilization, this cell divides into
  identical cells. In humans, approximately four days after
  fertilization and after several cycles of cell division, these cells
  begin to specialize, forming a hollow sphere of cells, called a
  blastocyst

but do not explain why they begin to specialize.

I could imagine

that a cell has a "counter" on the number of divisions which triggers differentiation after a given amount of divisions
or a chemical substance (either cell-borne or external) forces a change in the division

but why some cells would become "cell A" and some others "cell B"?

I am fairly sure that the biochemical mechanisms which regulate the life of a grown up mechanism can explain cellular differentiation (through hormones for instance) -- I am however interested by this specific moment, this n-th division where identical cells become differentiated.


texts:
I was reading this review and came by this:

  Direct pharmacologic inhibition of RAS has been a major challenge.
  Interference with the nucleotide-binding pocket of the protein seems
  to be far more difficult than interfering with the analogous
  ATP-binding pocket in kinases. This is presumably due to the much
  higher (picomolar) affinity of RAS for GTP.

What is meant by affinity? How do inhibitors work (in this context)?
Kindly help me as to what does this mean, I am new to biochemistry.


texts: Electron Transport Chain Proton Pumping into the Intermembrane Space

texts: In regards to the electron transport chain, I know that complex I pumps 4 H+, complex III pumps 4 H+, and complex IV pumps 2 H+, but where do these numbers come from? If someone could explain this, that would be great. For example, I'm confused at how 4 H+ are pumped when only two enter complex I via NADH + H+.


texts: What signals a ribosome to stop production when the cell is out of available amino acids?

texts:
In the production of a protein molecule, there have to be a ready supply of free-floating amino acids. When a given codon for adjoining, say, serine comes up, how are the serine molecules found out of a soup of 20 different types of amino acids?

For example,

Meleagris gallopavo (turkey) small muscular protein
NCBI Reference Sequence: XP_010724014.1  88aa GI: 733873411

 1 mskqpashvk aiqaninipm gafrpgaghp hkrkevtpee veesvpatee ekdkkhlpga
61 iklpgpavnl seiqniksel kfvpkaeq

has 9 alanines, 1 aspartate, 11 glutamates, 2 phenylalanines, 5 glycines, 4 histidines, 6 isoleucines, 11 lysines, 4 leucines, 2 methionines, 4 asparagines, 10 prolines, 4 glutamines, 2 arginines, 5 serines, 2 threonines, 6 valines, 0 tryptophans, 0 cysteines, 0 tyrosines.

So the cell would deplete glutamates much faster than aspartates and obviously infinitely faster than tryptophans. So, as the concentration of glutamates drops drastically with the production of each new turkey muscle polypeptide strand, getting diluted by the nonreactants tryptophan, cysteine, tyrosine, wouldn't the reaction rate get exponentially slow?

And when the last available glutamate residue gets attached, and if it happens before the polypeptide is complete, yet it needs one more glutamate to complete the chain, what signals the ribosome to "stop looking for more glutamates"?


texts: How does lactate produced in the intestines get transported to the rest of the body?

texts: Some gut bacteria known as lactic acid bacteria(LAB) are known to produce lactate in the intestines and they confer beneficial effects such as enhancement of the immune system, but I assume not all of the lactate stay in the intestines and some of them will get transported to the rest of the body and used by other tissues (e.g. cori cycle). If that's the case, do these lactate enter the circulatory system? Are there any articles reporting it?


texts: Septic Shock: I'll kill myself before you kill me

texts:
Most of the deaths caused by extracellular bacteria don't actually result directly form their action. Rather, it results from an overreaction of the immune system to antigens such as LPS and LTA (Superantigens are bacterial toxins with an enormous power in originating immune responses; they are able to activate numerous T cells through a different TCR, which will produce too many pro-inflammatory cytokines, resulting in an excessive reaction by the body and causing self-tissue damage, etc), and it is this excessive reaction of the immune system which ends up killing the organism.

http://www.medicalnewstoday.com/articles/311549.php
http://www.medicalnewstoday.com/articles/305782.php?sr

How come, after all this evolutionary time, we have this self-killing mechanism? Why do T-cells have receptors to such generalized and potent antigens, which will frequently result in self-damage? Is it because at the point of infection that this happens, we would die anyway from it, so it doesn't alter fitness?


texts: Unlike humans, why do plants not have something blood-like to transport $O_2$ throughout their body?

texts:
Since plants have a large number of stomata at different parts of their body, they can get $O_2$ at almost every part of the plant and so, they don't need to transport it throughout the whole body whereas in the case of human beings, they can only intake $O_2$ through their nostrils, but a large number of organs throughout their body require it. So it needs to be transported. And for this reason, blood is present.

Let me know if I'm wrong and what the actual answer is.


texts: Gibbs free energy and its change for the hydrolysis of ATP

texts:
So in my book I have the reaction

$$ATP \rightarrow ADP +P_i$$

and hence $$\Delta G^0 = G^0_{ADP} + G^0_{P_i} - G^0_{ATP}$$

This is easily understood, but I have not been given any actual concentrations of values to use to calculate the result, which is given as

$$\Delta G^0 = -31.0kJ\text{mol}^{-1}$$

  Where do I find the values of $G^0_{ADP}, G^0_{P_i} \text{ and } G^0_{ATP}$?

I have the formula $$\Delta G = \Delta G^0 + RT\ln \bigg( \frac{AB}{CD} \bigg)$$

where $A,B$ are the concentrations of the products and $CD$ are the concentrations of the reactants.


texts: How realistic is to use DNA for long term storage?

texts:
This is mainly a followup question to the recent paper Next-Generation Digital Information Storage in DNA.

Personally, while I agree about the data density of the format, I can't help point out the large issues with the inability to rewrite and recopy the data efficiently and potential issues regarding the "immutability" of the data. I'm curious about other takes on the publication and whether or not the stability of the DNA as well as the "writing" inefficiencies are better than I'm believing.


texts: What is the name of this moth found in Virginia USA?

texts: Found in Virginia, USA on Nov 1 2015, 10:34 AM.


texts: Statistics on energy consumption breakdown per biological functions across organisms?

texts:
Are there any statistics available on how much energy organisms use for each biological functions (i.e. something similar to the line of "Bacteria spend X% of energy on information processing, Y% for tissue maintenance and Z% for locomotion. Mammals spend..."). I'm particularly interested on how much energy is spent on information processing.

I vaguely remember seeing such stats somewhere, but for the love of god I can't remember where...


texts: What impact do genetic engineering techniques have on seed breeders?

texts:
In research of seed breeding, I'm trying to understand the impact of genetic engineering techniques like CRISPR (This is the main one as I understand) on traditional seed breeders. Through searching on the internet, I believe to have found the following two types of impact:

research: increased speed of detection which genes make for which vegetable trait. This is supposed to be used already by many breeders.
Growing: Reducing the breeding cycles by up to a factor 2, by early selection which plants are the good ones in the breeding process (I don't really understand how this would work)

So the main total impact of new breeding technologies would be the shortening of breeding cycles, putting increased pressure on fast innovation.

Am I missing any type of impact? Is CRISPR going to change seed breeding in a dramatic way? For instance, is there a way to take someone else his/her seed, then using crisper (in some way?) to immediately know which genes make up for the desired vegatable traits? Or some increased speed in which one could copy traits of other seeds? Also I'd like to know how the second point works: using CRISPR to reduce the breeding cycles for seeds.


texts: So, after starting to gain weight on sitting in front of my computer too long, I have decided to take the plunge and maybe stick to an exercise regimen. As has been reported by some studies, exercising in the morning can be more beneficial than doing so in the evening. Now, personally, waking up in the morning is a huge chore for me. Furthermore, I have people advising me to hit the loo (toilet) before exercising as it may not be good for my health and leads to waste accumulation in the body. Now, search as I may, I cant find any basis that supports this theory. I understand that hygiene might be a factor but does exercising in the morning before going to the loo have any effects on health in general? Thanks.


texts: How do I change bond colors to something besides a different hue in Coot?

texts:
I can modify the colors of carbons in Coot under Edit, Bond Colours..., but that only gives me different hues.  Is there a way to change the color to something less-saturated (or perhaps slightly transparent) so I can identify the "active" molecule I'm working on versus a template?

The menus seem no help, I'm wondering if there's some scripting magic that can do this.


texts: What are the obstacles to "refitting" the human body's metabolism?

texts:
As a layman, I understand the problem of rising obesity like this:

In the old times, humans could never get enough food, thus they would eat whatever they could get. This "program" is encoded in our genes.
At least in industrial countries, the ubiquity of energy-rich food makes some of us get obese, at least partial because we follow this old "program".

I hope I didn't get it too wrong. Now my question is this:

Would it be possible to somehow "rig" the human body to change the metabolism and make it fit to a rather sedentary lifestyle?

For example: Instead of storing surplus food / energy within the body, it could be excreted, thus keeping humans at their weight even when eating a lot more than they need.

Could this be possible? Which organs/hormones control the utilization of food within the human body and can they be influenced in such a way?


texts: Is a species lifespan affected by meat consumption?

texts:
I read a review-like article about the hypothesis of Caleb E. Finch  in a science magazine. The article of interest engages with the idea of Finch

  "[arguing] that immune functions and nutrition have been of major importance in the evolution of aging and longevity."

According to this, humans started to regularly consume meat. Meat itself, carrion or injuries during hunting have chances of getting infected and thereby causing death to humans. A strong defensive system against infections lets you survive and its coming into existence may be accompanied by an elongation of our lifespan.
I find myself now asking two questions:
(1) Because the whole article is only about the primate branch, I wonder, whether there are other omnivores that drifted apart concerning their eating habits and if now there is a more carnivorous, longer-living genus?
(2) Do carnivores, in general, have a long lifespan (or is their lifespan highly dependent on a healthy predator–prey equation)? I tried googling, but could not find a relevant scientific resource on this topic.


texts: I'm from a maths background and I'm doing some research on mathematical models of cancer. I've come across alot of literature mentioning "multicell spheroids" in the context of avascular tumours. I know that avascular means a lack of blood vessels but I am having trouble finding an explanation for multicell spheroids. Are these some kind of model/approximation of a certain types of tumours, or are they actually a real-phenomenon in and of themselves? It would be great if someone could fill me in on what they multicell spheroids actually are!


texts: Why was it initially thought that Mendel's findings were contradictory to Darwin's natural selection?

texts: When I read about the modern evolutionary synthesis, the text said that it showed both ideas to be compatible, once thought to be contradictory. Would it be because Mendel described an element of "randomness" in character transmission, as opposed to the mechanism of natural selection originally described by Darwin, or is it something else? I do not yet have a big knowledge on evolution, so pardon any mistakes.


texts: "Other" classification for epitopes in the Immune Epitope Database (IEDB)

texts:
I used the immune epitope database (IEDB) to search for epitopes. I found some epitopes derived from antigens called " other" by IEDB.  When I asked about it,  the answer was "We use the "other" category to group epitopes from the same species that only BLAST match to GenBank entries that are nonhomologous to the reference proteome".

Could someone explain this?


texts: Would a hole in a heart make it unsuitable for transplantation?

texts: Would a hole in a heart instantly make it unsuitable for transplantation? Or could it be possible for a heart with a congenital defect to still be suitable for use is someone else's body?


texts:
As far as I know, SARS-CoV-2 tests currently used worldwide are real-time RT-PCR. Why there is no ELISA for SARS-CoV-2?

Compared to PCRs, ELISA is:

Way cheaper;
Way faster;
Does not require trained technicians or complex equipment.


texts: In terms of differentiation, how many generations of asexual reproduction, will usually be equal to 1 of sexual?

texts: As far as I understand, in sexual reproduction, there is a mix of 50/50 genes from parents. In how many generations of asexual reproduction, will offspring reach differentiation level that of sexual one ?


texts: How can the number of genes increase through evolution?

texts:
I am aware of the basics of evolutionary theory, however I don't understand how mutations can add genes over time.

Am I correct in thinking that creatures within the same species who mutate to have an additional gene in their genome would normally be infertile?  Or am I misunderstanding that?

Can someone explain the process of the creation of genetic material through evolution?  Citation to a decent academic paper or book on the matter would be appreciated too.


texts: Basic Local Alignment Search Tool (BLAST)

texts: Why would BLASTP (Basic Local Alignment Search Tool) be a poor tool to search for motifs in protein sequences?


texts: Is there any relation between weight class and extreme lifting performance in O-lifting?

texts:
We usually thought that weightlifting is a tough game. It is only for great physique.

There are 6 man in history who lifted  3 times their body weight. Check here.

3 of them are Bantamweight(56kg), 2 of them are Featherweight(60kg), and 1 is at Lightweight(67.5kg).

All of them are light. Is there are fact that light weighted are more efficient in weight lifting?


texts: Do we know if RHEB is more sensitive to some amino acids than other amino acids?

texts:
RHEB (Ras homolog enriched in brain) senses amino acid levels in order to recruit mTOR.
See this review describing the process of how RHEB recruits mTOR. So does RHEB have differential selectivity towards different amino acids.

We also discussed this in Matt Kaeberlein's class yesterday and I posed this question but no one could answer it (that said, Matt Kaeberlein called it a good question).


texts: Is it possible to have multiple stop codons in one exon?

texts:
I would be very happy if someone can help me to find the answers for the following related questions.

Can one exon have many stop codons?
Can protein synthesis happen, if the stop codon is at the beginning of the exon?


texts: What's the Efficacy of Ampakines in the Treatment for ADHD? Ampakines are a class of drugs that serve as potentiators of the AMPA glutamate receptor. By so doing they serve as nootropic, anxiolytics and antidepressants.


texts: Is the amount of the soil reduced when plants grow?

texts: According to the principle of mass conservation I think the amount of the soil should be reduced when plants grow. But this reduction is not typically observed. For example, some trees (big trees) grow so fast that if the soil was reducing due to the growing trees, it seems like no soil should be left around them (i.e. the soil surface had to go noticeably down). But it didn't occur. So, which matters are reduced by growing plants?


texts: Nutrient limitation in terrestrial and freshwater ecosystems

texts: In terms of primary production, it is often described in textbooks that nitrogen is the most limiting nutrient in terrestrial ecosystems, while phosphorus is the most limiting nutrient in freshwater ecosystems. What creates this difference?


texts: Can epigenetics have positive impact on the genes are development?

texts:
I know that epigenetics have capacity to affect and degrade the genes thereby inducing problems/illness/degradation in body functions.

Can they also make better genes or have positive impact on genes or body? If yes, can someone give some examples?


texts: Question about mutation of multiple nuclei?

texts: If an organism with multiple nuclei, such as the slime mold Physarum polycephalum, was to be exposed to a mutagen, such as 5-bromouracil, what would be the effect (besides death)? Especially if multiple nuclei were effected differently by the exposure.


texts: Ventricular Filling : Systole or Diastole?

texts:
As the Blood goes down from the Atrium to the Ventricles:

The Tricuspid Valve ( Right Atrioventricular Valve)
Bicuspid Valve (Mitral Valve )

The atrial pressure is INCREASES WHEN ATRIA ( THE ATRIA CONTRACTS AT THIS STAGE/ATRIA SYSTOLE) Thus:

fills the ventricles with blood ( blood goes down from the atria to the ventricles)
The Tricuspid/ Bicuspid valves OPENS since there is a higher pressure of Atria than the Ventricle

Questions:

Is the Ventricular Filling, (When Blood from Atria fills the Ventricles) itself a DIASTOLE or SYSTOLE
So during the Ventricular Diastole
Ventricular Filling is Diastole?? ,
Is it when VENTRICLES are filled with blood :

  it increases THE PRESSURE IN IT SO THAT IT MAKES A
  (** VENTRICULAR DIASTOLE /VENTRICULAR CONTRACTION **)

I also saw in here that:
" The P wave represents the atrial electrical depolarization. This phase is ventricular diastole. During filling, pressure within the right atrium increases, pushing blood across the AV valves into the right ventricle."

I'd also like to clarify:

    Shouldn't it be  WHEN IT FILLS THE VENTRICLE is filled,
     THE PRESSURE GOES LOW in atria gradually within the???
    I get it that the atrium has a HIGHER PRESSURE BEFORE FILLING and it makes the (TRICUSPID AND BICUSPID) valve OPEN

Kindly clarify through diagrams and steps, I'm somehow confused. Thank you!
You can kindly watch this short clip of video and this may help me clarify things:

http://highered.mheducation.com/sites/0072495855/student_view0/chapter22/animation__the_cardiac_cycle__quiz_1_.html


texts: How could humans have interbred with Neanderthals if we're a different species?

texts:
To be clear, I'm not doubting that homo sapiens and homo neanderthalensis did interbreed: of that much I'm convinced.

Within the past few years I've seen an upcropping of pop-sci articles discussing the interbreeding between pre-historic species of humans. In everything that I see in these articles, as well as in scientific literature (my college Bio textbook, among others), I see these different humans being referred to as separate species.

This conflicts with my understanding of a species. Given the following definition, wouldn't homo sapiens and homo neanderthalensis be the same species?

  A species is often defined as the largest group of organisms where
  two hybrids are capable of reproducing fertile offspring, typically
  using sexual reproduction.  ~Wikipedia

Is this definition incorrect?
Are the publications using "species" colloquially, as opposed to scientifically?
Is "species" still a poorly defined concept? (see Ring Species)

Thanks!


texts: Why do nattokinase and serratiopeptidase remain effective when given orally, but not insulin?

texts:
Why do nattokinase and serratiopeptidase not break down in the stomach and intestines?

Article says that serratiopeptidase is absorbed in rats intestines after oral intake - https://iubmb.onlinelibrary.wiley.com/doi/abs/10.1111/j.1470-8744.1994.tb00308.x


texts: Is there any treatment for allergy? I am not saying about solutions like epi-pen which reduce the symptoms. Is there any way to modify our immunity so that it does not identify the allergens? Can we modify our WBCs to not identify them?


texts:
Imagine an isolated population in which each adult female has a distinct mitochondrial genome. In each generation, every adult female has two children (with a 50% chance of being male or female). After each generation, we will assume that all the adults die out, and all the children become adults.

After four generations, what is the expected percentage of mitochondria from the original population of females that will still exist in the population’s children? Express your answer as a decimal between 0 and 1, rounded to three decimal places.

Note: after one generation, there will be 100% of the mitochondria from the original population present in the population’s children since male children receive the mitochondria from their mothers (but do not pass them on to their own children.)


texts:
While going over PCR in my biology lecture this week I have come across a few questions I have about this process.
First, since PCR focuses on trying to replicate a specific targeted DNA sequence many times in a short amount of time, are the primers used in every cycle the same sequence? I understand the forward and reverse primers would not be the same but the forward primer for one strand in one cycle, would it be the same as the forward primer for a daughter strand of let's say the 8th cycle?
Second, why are primers not reusable for different cycles? I think this would be based off of the answer to my first question. If the primers are essentially the same sequence, why do new primers have to be used for every cycle?
Thank you in advance!


texts: THYROGLOBULIN (19S) comes to a heavier position than ferritin (51S). Why?

texts:
Sedimentation values of thyroglobulin and ferritin containing iron are 19S
[1] and 51S [2], respectively. But, by density gradient centrifuge, it seems thyroglobulin (19S) migrates faster than ferritin (51S). Could anyone explain this?

Figure 3 in this article shows a migration pattern of GE High molecular weight marker containing ferritin and thyroglobulin. Thyroglobulin comes almost at the bottom but ferritin, in the middle, which I did not expect.

PS
I asked GE and confirmed ferritin in the marker contains Fe ions.


texts: Where does meiosis II of oogenesis end exactly in tuba uterina - uterus?

texts:
I know that metaphase II ends at ampulla tuba uterina, but I am not completely sure where the telophase II ends. Is it in the triangular section of cervix uterii?

I just have an intuition that the thing is not ending at the ampulla, since there is some time to get to the uterus. The thing must happen before implantation to the uterus, since the egg is blastocyst at the stage.

2. When does meiosis II of oogenesis end exactly?


texts: What nocturnal animal sound am I hearing in the trees in Maine?

texts: Every year, during late summer nights (usually around 9:00 pm) in Maine, I hear a noise coming from high up in the trees. The trees I hear it from are mostly maple or conifer, but where I live there are few trees that are not. It sounds like a cardinal's chirp (fourth sound down in link), but longer, scratchier, and lower pitch. The sound starts and ends abruptly. There are three to six chirps in a row from the same tree, and then silence for a few minutes. Sometimes I will hear it again after a few minutes from the same tree and sometimes from a different tree. The skies are usually clear when I hear it. No one else in my family can hear it. I live in a suburban area, but when I go to a more densely forested area I hear it more frequently. Does anyone know what this is?


texts: Are coronaviruses gaining an evolutionary advantage?

texts:
So there are 7 known strains of coronavirus that are known to infect humans: 4 that cause the common cold (229E, NL63, OC43 and HKU1), and 3 that have been known to cause acute respiratory infection (SARS, MERS and now COVID-19). They're all beta-coronaviruses except for 229E and NL63.
I can't help but notice the latter 3, which also happen to be the most serious, have all emerged very recently and within less than a decade apart from one another. I tried to find out how long the common cold strains have been around for, but can't find too much information on that (I found one article from science daily that says the common cold could have originated in birds around 200 years ago, but that's about it).
Does anyone have more information on this? Is the fact that SARS, MERS and COVID-19 emerged so close to one another a trend or just a coincidence? Are there any notable scientists who've noticed this and have an explanation as to why?


texts: Is downregulation of neurological receptors fully reversible, i.e. complete upregulation and resensitization?

texts: Are down/upregulation truly reciprocal mechanisms? After a binding ligand or agonist is removed, such as a prescription medication, is upregulation and resensitization able to occur to a level that exactly equates to and completely reverse and fully make up for any loss of receptors, bonding affinity, etc? Could anything theoretically be permanent? Does time/length of prescription play any role in this, including when prescribed a benzodiazepine (Clonazepam)?


texts:
I've seen the plots and they don't look drastically different. Why do this?

Why use a logarithmic scale when plotting pharmacodynamics/kinetics?


texts: I would like to ask if there's any method (established or not) in order to quantify heterogeneity found in mutations occuring in primary neoplasms and metastatic lesions (either common or private) and potentially correlate this number to standard clinicopathologic traits.


texts: Why can I raise my left eyebrow independently from the other but not the right?

texts:
I've seen the same question on other forums, but have not come across any definitive explanation.  The non-cited answers seem to fit into three categories:

It is due to greater muscle dexterity on one side of the face.
It is a result of being either left/right brained.
It is genetic.

Perhaps it has to do with a combination of these three, or none of them at all.  Some have even said that with practice they have been able to raise both independently from the other.  Why is this so?


texts: Energy cost of chewing vs production of enzymes

texts: Consider a hypothetical case that you ingest a piece of starch. Which is more costly energetically 1) chewing + reduced amount of enzymes production needed or 2) sole production of all the enzymes for digestion for achieving the same amount of glucose absorption given the digestion time is constant. (There could be different answers for different sizes of starch ingested)


texts:
Location is in Canada / Ottawa

I did a web search, but I can't figure out what species it is.


texts: How to identify active protein in a complex mixture?

texts:
I am trying to figure out how to identify which protein in a complex mixture is producing a certain effect.

There is an assay for the effect, so anything (a fraction of the mixture) can be tested on microplate.   The part of the mixture producing the effect is pretty definitely a protein (or has a protein component).

Unfortunately, the mixture is serum... which contains >10,000 proteins and peptides, some in tiny amounts and some in huge amounts.

There is not enough information to go the other way, ie guess what is producing the effect and test that by itself (or remove it from serum and test the depleted serum as a confirmation).

There is also no possibility to use affinity (use a receptor as bait, etc) because many components of serum stick to the cells in the assay (or, practically to any cells).

I need a way to narrow this down from "serum" to one specific protein (or a handful), but how?


texts: Which data format for mRNA expression matrix is necessary to run pathway analysis with Paradigm?

texts:
I am running Paradigm on a matrix of mRNA expression. I read

  Vaske, Charles J., et al. "Inference of patient-specific pathway activities from multi-dimensional cancer genomics data using PARADIGM." Bioinformatics 26.12 (2010): i237-i245.

and also the help section in the web application. However it is not defined which format is best-suited for mRNA expression. Using log$_2$-ratios instead of log$_2$ data format gave me different results.

Thanks


texts:
These insects lived inside the wood of my bed in little round holes. They bite, lеаving very itchy red marks. And when crushed stink really bad. In the picture the lines are notebook lines for size comparison.
   I live in Eastern Europe, so I don't think they are fire ants, if they are ants at all.
Any suggestions would be appreciated!


texts: Is a nightly curfew an effective intervention strategy for limiting the spread of an infectious disease?

texts:
The governing bodies of several geographic areas hit by disease outbreaks will sometimes impose a nightly curfew on their citizens, restricting or limiting the ability of their citizens from going outside during certain hours of the night (or day). As I write this, several United States local or state governments are implementing such strategies in March 2020 to contain the COVID-2019 coronavirus pandemic (Puerto Rico and Hoboken, New Jersey both have nightly curfews as of March 15, 2020).

My question is: does any data exist showing that these measures are effective, or counter-productive? My intuition is that a nightly curfew could actually accelerate the spread of an infectious disease, because citizens who have to leave their homes to do errands are all obligated to do them during a shorter time-window, thereby raising the number of people present in public places at any one time. I couldn't find any published research directly assessing the effectiveness of nightly curfews as an epidemic response strategy. (I only found articles such as this one discussing the failure of nightly curfews in Liberia during the 2014 Ebola epidemic, but those caused public rioting and low compliance). Considering how common this is frequently mentioned and attempted as an intervention strategy, what were the results? Is there any published data from real-world examples, or even results from model simulations?


texts: what is the active ingredient in cymbopogon citratus that repels mosquitoes?

texts: We are doing a project about mosquito repellants using lemongrass, cymbopogon citratus. But, based on our researches online, it stated that it was all a hoax and a better alternative is its cousin cymbopogon nardus.So, is the hoax actually true??? And please tell about the active mosquito-repelling ingredient.


texts: How can low cholesterol cause mortality?

texts:
I am studying processes 1. stroke, 2. heart disease, and 3. cancer, and their mechanisms associated with low cholesterol which is a result of lowering cholesterol especially in elderly, Low cholesterol is associated with mortality from stroke, heart disease, and cancer: the Jichi Medical School Cohort Study.
Stroke's manifestation is primary intracerebral hemorrhage ICH confirmed by many exclusion articles of other factors such as liver disease).
In the heart disease, there CAD and ischemia.
In the cancer, metastasis.

I started to think what could be enough general for all of these.
In the energy sense, one possibility could be glycogen, since it is used as an acute energy storage in all those organs.
Mechanisms could be the macro/microstructures of storage which are mostly unknown, presenting roughly 80/20 proportions.
So I propose that the lack of energy causes those conditions.

I noticed that many authors use the word remnant cholesterol when speaking about the subject. I did not understand its biophysical meaning.
Remnant cholesterol is an independent factor of cardiovascular manifestations apparently through the larger triglyceride-rich lipoproteins' (TRL) remnant kinetics.
Remnant cholesterol does not seem to cover all aspects of low cholesterol.

How can you low cholesterol cause stroke, heart disease and cancer?


texts: Heterocyst function in cyanobacteria and its localization

texts:
1.What is the function of heterocyst?

2.Where it is present?

A heterocyst I think may be a protecting organ in cells!


texts: How closely related are two parasites Giardia intestinalis and Trichomonas vaginalis?

texts: How closely related (from the evolutional point of view) are parasites Giardia intestinalis and Trichomonas vaginalis? Giardia genome is about 12 Mb and its major cellular proceses are rather simple. The genome of Trichomonas is approximately 160 Mb. What about its cellular processes, is it also a 'minimalist'?


texts: Why rectus abdominis is not proximal muscle?

texts:
I am thinking this picture which shows proximal muscles.

Why for instance pectoralis major, subclavius and rectus abdominalis are not included in proximal muscles?


texts: Is there sufficient evidence that human cells are not intelligent?

texts:
Being structurally composed of one or more cells, which are the basic units of life.
Yet within a cell, there seems to be the same behaviors that define life:

Regulation of the internal environment to maintain a constant state;
Organization: Don't most cells have organs?
Metabolism.
Growth ~ not sure about this one.
Adaption ~ Think this is accurate, but I'm not well versed in cellular biology at all.
Response to stimuli. Cells interact with external whatnots.
Reproduction - Cells do this, at least many of them.

Most of what lead me to this question came from chapter 5 of Spontaneous Healing by Andrew Weil, M.D.. I'll type the parts relevant to the discussion below - in case he's wrong and I'm basing my thoughts on wrong information. bold sections indicate my interjection

DNA takes the same form in all organisms, from human beings to viruses - an enormous molecule with a double-helix structure made up of two chains of sugar molecules, with "rungs" linking the two chains. The rungs form between complementary pairs of nitrogen-containing subunits 'nucelotides', whose specific sequences differentiate the DNA of one organism from that of another. Only four different nucelotides occur in DNA; they are the "letters" of a genetic code spelling out "words" of information that direct the construction and operation of all forms of life. The so-called Central Dogma of modern molecular biology states that DNA replicates itself in order to pass its genetic information on from one cell to another and from one generation to the next reproduction; DNA also transcribes its information into another macromelecule, RNA, that can travel out of the cell  nucleus; RNA, in turn, transslates this information into the manufacture of specific proteins that determine the structure and function of organisms. regulation? These three processes - the replication, transcription, and translation of genetic information - are the most basic processes of life. They are also amazingly intricate and risky, because there are so many points at which things can go wrong.

Snipped for relevance.

Therefore, sophisticated mechanisms have evolved for the repair of this molecule in order to assure nearly error-free transmission of genetic information from one generation to the next, even in the simplest forms of life. organization, regulation, reproduction - evidence of response to stimuli?
All of the mechanics of replication, transcription, and translation are directed by a special class of proteins called enzymes. A great deal of the genetic code specifies the manufacture of enzyme molecules, which, in turn, oversee the chemical reactions that develop the genetic code into biological reality. evidence of intelligence?

much snipping.

In practical terms, they (enzymes) function as ingenious machines that alter the substrate molecules: cutting them apart, putting them back together, snipping particular pieces off them, adding others back, all with astonishing precision and speed.

more snippage

Therefore, polymerase I actually proofreads its own work, editing mistakes as it directs the synthesis of new copies of DNA.

He goes on to talk about plasma membranes, which seem to be how cells interact with the "outside" world..


texts: Does GTP-γS (GTP gamma S) bind all GTP-binding proteins?

texts:
I've just read an article Rab10 GTPase regulates ER dynamics and morphology - Nature Cell Biology 15, 169–178 (2013) doi:10.1038/ncb2647. In this paper, to identify Rab proteins in ER, first they isolated ER vesicles. Then washed them to remove cytosolic proteins. After washing, these vesicles were solubilized by detergent. Then, it was loaded on to a GTP-agarose column (to bind GTP binding proteins to the column). In the last step GTP binding proteins were eluted with GTP and analysed by SDS-PAGE.

As a control (before loading on to the column) they used GTP gamma S, because it prevents GTP-binding proteins from binding onto the column.
When I looked at their figure; on the control lane, there are lots of bands! So I'm confused :(If it prevents GTP-binding proteins from binding onto the column, after eluting from GTP agarose column why there are bands? And what can these bands be?)


texts: What are the psychedelic effects of (star) anise and how many people are affected?

texts:
Backstory:

My girlfriend reacts heavily to chocolate and drinks containing stellar anise, in a way that seems comparable to psychedelic drugs.

After consuming it, it takes approximately five minutes for the reaction to become apparent.

Observed Effects:

Due to the heavy reaction, she tends to avoid these foods, however, we could observe the following effects:

Heavy giggling, occasional outbursts of loud laughter;
Much less frequent: Crying (just kind of starts from the giggling and subsequently fades back into giggling);
Minor hallucinations (Sparkling hair, glowing faces);
Loss of motor skills, especially balance;
Feeling time pass much faster (to her, a 15 minute episode felt like 1-2 minutes, an hour like 5-10 minutes);
Some memory loss (probably related to the time perception?);
Unfocused mind;

Her speech remains clear and articulate.

Observations are anecdotal, as I only observed two episodes, and we realized what happened only after the first.

Googling Results:

Apparently, around 1-3% of humans react in some way. However I couldn't find any detailed explanations of the hows and whys, nor any actual research.

I am very curious about this. Is it dangerous? Are there any related effects (genetic disorders, maybe?). All explanations, and hints how to google better, are welcome.


texts: Help in identifying an unknown Golden Worm/Larvae

texts:
Can anyone help me to recognize this type of species? Is it a clustered worms or clustered larvae? Location is in Bali, Indonesia. Recently this species is goes viral, but people here always link this species to a myth.
Thanks.


texts: Do egg laying animals experience a pregnancy?

texts:
Does a female animal that lays eggs experience a pregnancy-like period of time, where she will feel and behave differently as if she were fertilized and her body is prepared to lay a fertile egg, not a sterile egg (like the chicken eggs we eat)?

For example,

does the egg takes more time to be formed?
is it different in size?
maybe the animal will feel hormonal changes that cause it to increase body heat to help her sit on the egg, etc.?


texts: Nucleotide sequence for STRING protein sequence

texts:
I have protein sequences from STRING database:
The amino acid sequence files are like this:

  4932.Q0010 (Saccharomyces cerevisiae)
  MYYIMFLYNMLLIIILIFYSIVGVPIIIFNNNYYWDPDIFLFIIYYFIKFIIIFNLYLYYMINYIVYTPSGSPPGRGTYI
  LLYNMLYSYNMFIDYVMKFITCVTYMYLMFWLLSPTPSPYYVSEVPVS

I want the corresponding nucleotide sequence for the same protein ID.

  4932.Q0010

I tried emboss http://www.ebi.ac.uk/Tools/st/emboss_backtranseq/
But emboss is based on codon usage and backtranslate and it doesn't give me the original nucleotide sequence.

Then I tried DDBJ http://getentry.ddbj.nig.ac.jp/top-e.html
But DDBJ gives only amino acid sequences for corresponding Uniprot ID.

How do i get the original nucleotide sequence for the STRING protein sequences using STRING id or UniProt ID?

Any help in this regard is highly appreciated.


texts: Clarification of the procedures to amplify cDNA needed

texts:
The typical procedure to obtain cDNA from genomic extracted DNA is the following:

RNA is extracted from desired tissue, RNA/DNA hybrid is obtained by virtue of reverse transcriptase RNA dependent DNA polymerase, H RNAse creates gaps in RNA of DNA/RNA hybrid and with the aid of a typical DNA polymerase dsDNA is transcribed, right?

Then, the newly synthesized cDNA is linear (like a "small chromosome")?
How is it protected from the nucleolytic activity?
Is the procedure really like I described or does the reverse transcriptase already give a dsDNA from single stranded mRNA?


texts: What does "Activation" refer to in the context of the symptoms of Schizophrenia and Schizoaffective Disorder?

texts: In this journal article certain symptoms are called "activation" in nature. I have never come across this term prior to coming across this article, so I would like to know quite simply what does it mean.


texts: Can you make sperm and eggs from the same person using in vitro gametogenesis?

texts: In a recent popular science article there is a discussion of the potential disruptive technologies that could become available with in vitro gametogenesis (IVG). Using skin cells you will be able to create either sperm or eggs. Thus, using stolen cells from Brad Pitt (simpler than getting his sperm) will allow a woman to have a nonconsensual child of him. What is not mentioned in the article and thus my question: Does this technique currently allow, (at least in mice), to make sperm from a female and eggs from a male? If that is the case, what will be the result of fertilizing sperm and egg from the same individual: a clone, a genetic "sibling" (not an identical twin), or neither of them?


texts: CRISPR/Cas9: What are the main differences between sgRNA and the Cr:TracrRNA ?

texts:
So from what I understand, in gene editing, the CRISPR vector expresses a small RNA sequence comprised of a small guide-RNA that is complementary to your target sequence. The sgRNA comprises a 20 Bp CrRNA and a truncated (cut down) TracrRNA right ?

My main question is how does this truncation enable gene editing ? After all, the bacteria have a full TracrRNA and not a truncated one.


texts: Can different strains of Rhizobium share an infection thread or symbiosome?

texts:
Rhizobium infection can be triggered at root hairs of legumes, creating infection threads.

Can these infections threads be colonized by more than one type of Rhizobium (e.g. Fixing and non-fixing)?

What about when the infection is inside the plant cells? Can symbiosomes be co-inhabited by different bacteria?


texts: Why do different bacteria have different shapes? Is it only related to their function?


texts: What is the significance of interclonal cooperation in tumorigenesis?

texts:
I have been reading about tumorigenesis in Drosophila Melanogaster lately, there are 3 questions which I have in mind:

How does interclonal cooperation differ from the canonical tumor evolution model?
How do fly tumours differ from human tumours?
If interclonal cooperation is important for the evolution of a certain tumour, what testable consequences can be predicted?


texts: Difference In Telomeres Between A Thale Cress Plant And A Methuselah Tree

texts:
From what I have read and understood telomeres cap off how many times a cell can divide before it can no longer divide and that is what causes aging.

A thale cress plant apparently has a life cycle of 6 weeks before it dies, while the Methuselah tree has set the record at over 4,800+ years.

What is the difference between these two plants regarding their telomeres?
Is the cell division rate different between both plants instead of a telomeres difference?
If given ideal conditions what could the potential life-span of a Methuselah tree be?

Btw you don't have to answer all these. Just curious and looking for some insight into why the stark difference between both plants' aging.


texts: What do you see when your eyes are closed?

texts:
If you are in pitch black and you close your eyes, you sometimes can see strange shapes of various colors. A lot of the time these shapes and colors change as you observe them. This phenomenon still occurs if you are not in complete darkness.

I am wondering what this is that you are `seeing'? Is this phenomenon classified as seeing, as how can we be looking at something if our eyes are closed?

If you are not seeing these shapes and colors, then what you observe is pure darkness. What is this pure darkness that you are seeing? Since you are seeing it, is something stimulating the vision parts of your brain? Is it the back of your eyelid?


texts:
This accepted and most upvoted answer to the question Does grass alone produce enough oxygen for life? claims that plants are oxygen neutral:

  Plants are oxygen neutral The question wording is a bit misleading, as
  – surprise – plants do not produce oxygen. They produce oxygen only as
  long as they are growing, binding carbon in its mass. In long term all
  plants are oxygen neutral, as all oxygen which is created by them is
  again consumed when they dissolve, burn or are eaten, as carbon stored
  in them reacts with oxygen back to CO2. The more correct view how to
  describe this is not that plants produce oxygen, but that they store
  carbon.

I realize that a huge portion of our atmosphere's oxygen was produced by Phytoplankton, but the idea that plants produce zero net oxygen seems absurd to me. Is the information provided by that answer scientifically accurate? Please explain.


texts: "CO2 is plant food" - What is the actual effect of increased CO2 on plant growth?

texts:
A frequent talking point by global warming deniers is that CO2 in the atmosphere is actually beneficial because "CO2 is plant food". I'm a non biologist trying to figure out under what circumstances this is actually true.

Here are my thoughts so far:

Plant growth is more or less governed by Liebig's law of the minimum - the plant needs sunlight, CO2, water, nutrients in a certain composition, whatever is lacking limits growth
In addition to it's role in photosynthesis, water is needed to transport nutrients from the soil, so dry conditions can limit effective nutrient availability
The energy needed to assimilate CO2-carbon is independent of the CO2 concentration
The rate of photosynthesis is (within the limits given by energy etc.) governed by CO2 concentration and active plant matter
photosynthesis only works in a more or less narrow temperature band

From this, it follows that a higher CO2 concentration in air will boost plant growth only if everything else (light, water, nutrients) is abundant.

So I have two interconnecteed questions:

How wrong is my simplistic view, does my conclusion hold?
What do we actually observe in the wild or in experiments?


texts: If the haploid prothallium of a fern fertilizes itself into a diploid sporophyte, does this make all ferns clones?

texts: From what I understand in the alternation of generations in ferns, mature spores germinate into a haploid prothallium. But how does this gametophyte produce recombinant gametes if it itself develops mitotically from a haploid spore? And if the gametophyte produces its own (haploid?) eggs and sperm, how does it ultimately produce a diploid sporophyte with the same number of chromosomes as its parent? If the haploid prothallium fertilizes itself, that means it possesses two identical copies of its parent's chromosomes, which themselves are identical - there is no outcrossing between plants. So are all ferns genetic clones? Why even bother with meiosis if you don't have a recombinant mixing of alleles? Or do I have this totally confused?


texts: How quickly do estrogens break down in the environment?

texts:
Of all the synthetic hormones we use, estrogens are probably the most common.  They are used for birth control as well as hormone replacement therapy.  This researcher also shows that there is plenty of it in milk because dairy cows are often pregnant while they are being milked.

Estrogen is a sturdy compound, very much like cholesterol.  I was wondering if anyone had any idea how long it would survive in the environment, given that some people are concerned about it interrupting animals life cycles.  How fast does it break down in the wild?


texts:
I was going through sample questions for Science Olympiad, and one of the questions went like this:

  A cell is observed through a light microscope at 4x magnification. The cell takes up about half of the visual field. What is the approximate length of this organism?

I know from prior knowledge that a cell can be anywhere from $10$ to $100$ micrometers, but I don't know how to figure out a cell's size with the information I'm given. Usually when I do problems like this, I am given the size of the field of view. Is that not needed to solve this problem?


texts: Are ape communities more "anarchist" or "communist" in structure?

texts:
I am using these terms because we can imagine them quite good, I guess ;)

By "anarchist" I mean that the ape wants to live without the rule of others apes(same biological race or other) and he pursue his own goals (replication, getting food etc.)

By "communist" I mean working together in groups because of the "higher"purpose (better chance to protect themselves, getting food easier, other benefits)

I am particlarly interested in apes, excluding us, of course.


texts: Needle-like crystals observed in wild-grape wine under microscope. Potentially harmful?

texts:
I recently crushed and strained about thirty pounds of wild grapes to ferment into wine. About a month in, I did a visual inspection of the wine under microscope to try and identify some yeast and bacteria species. However I was more taken by the sight of many sharp, needle-shaped crystals in the wine (along with microbes). Pictures are below:

My best guess is that they are raphides (crystals of calcium oxalate/carbonate), a supposed defense mechanism of some plants. These seem to be complicit in causing acridity in certain plants, and indeed the grapes (and resultant wine) were extremely tart. I've not, however, heard of any wild grape species having known toxicity.

My question is, then: are any wild grape species known to produce such crystals and, if so, are they known to be harmful in any way? Is there another explanation?


texts: Using evolution of bacteria against themselves

texts: We know that mutations happen regularly in bacteria and also that one bacteria might get the mutation and become stronger than the others and thus survive, causing antibiotic resistance as well. Can we deliberately make mutations in bacteria that would harm other bacteria but not humans. This would not only make them stronger and thus let them survive but would reduce the very need of antibiotics as they would be less virulent to humans?


texts: Which turtle species was on board the Iranian Space Agency launch in 2010?

texts:
They are seen briefly in this video:

https://www.youtube.com/watch?v=nZoNdf6hlII

The launch made international news, but there was no mention of the species.

Here's the entirety of Wikipedia's description of the launch:

  On February 3, 2010, ISA launched a Kavoshgar-3 (Explorer-3) rocket with one rodent, two turtles, and several worms into sub-orbital space and returned them to Earth alive. The rocket was enabled to transfer electronic data and live footage back to Earth. The Iranian Aerospace Organization (IAO) showed live video transmission of mini-environmental lab to enable further studies on the biological capsule. This was the first biological payload launched by Iran. Iran is the sixth country to send animals in space.

The Farsi language Wikipedia entry on the launch (کاوشگر ۳) does not appear to contain any more information on the species.

I've tried searching Google Scholar for papers, but my search turned up nothing. I also tried asking Reddit on the day of the launch, also without results.

Bounty Note: I appreciate all answers, especially from herpetologists. However, the bounty will only be awarded only for a reliable, third-party, published source (i.e. acceptable for use on Wikipedia).


texts: What is the evolutionary advantage of breathing and heart beats syncing between partners?

texts:
I recently read that partners who are close to one another usually when touching have their heart beats and breathing in sync. Why does this occur? What is the benefit of it occurring? How does this occur?
The study linked below states that this phenomenon may reduce pain. Is it possible that is the evolutionary advantage? How is it that 2 peoples bodies sync their heart rates without knowing the other persons heart rate or being able to see the other persons heart beat?
Goldstein, Pavel, Irit Weissman-Fogel, and Simone G. Shamay-Tsoory. "The role of touch in regulating inter-partner physiological coupling during empathy for pain." Scientific reports 7.1 (2017): 1-12. APA


texts: if the load is removed from an eccentrically contracting muscle, will it start contracting concentrically?

texts:
Geometrically speaking, a muscle contraction should exert a force between the two attachment sites. However, the actual effect of the force on the overall geometry of the body near the point of attachment may not match the direction the force pulls. For example, although the bicep contraction in principle would pull the forearm closer to the humerus, instead during eccentric lengthening the arm is actually extending due to how the rest of the system is configured. This is an example of where the direction of force exerted by the muscle doesn't coincide with the movement of the

My Question:

Can a muscle's net effect on the geometry of the system it acts on change mid-way through contraction?

For example, if my arm is eccentrically extending due to too heavy a weight in my hand and suddenly I drop the weight and now the bicep can contract. That's a simple example but I'm wondering how common it is for a the effect of a muscle's action to change midway through.


texts: What substances can selectively destroy certain cells?

texts: Recently, I've watched a documentary about how, in the 1980s, people were buying and using drugs from the streets and then becoming paralyzed a few days afterwards. The drugs that they were using were contaminated with a substance called MPTP, which was able to selectively destroy dopamine-producing cells in the brain, essentially causing end-stage Parkinson's Disease, but leaving higher cognitive functions intact. Is MPTP unique in its ability to selectively destroy a certain type of cell, or are there other substances that can selectively destroy certain body cells while leaving the others intact? If yes, then by what mechanism do they work?


texts: What's the difference between releasing hormones and tropic hormones?

texts:
I've been reading my textbook and two terms have appeared that, after a bit of looking, I still can't seem to be able to distinguish. Here's what the textbook says (McGraw Hill Bio 12, 2011):

  After receiving signals from various sensors in the body, the
  hypothalamus secretes what are referred to as releasing hormones,
  which often travel to the pituitary gland. The releasing hormones
  stimulate the pituitary gland to secrete hormones that act on other
  endocrine glands. Hormones that stimulate endocrine glands to release
  other hormones are called tropic hormones. (pg. 394)

From the work I've done, it all seems to indicate that releasing hormones regulate the secretion of other hormones, and that tropic hormones target and stimulate other endocrine glands (to release hormones). And yet my textbook appears to use the terms separately later on as if they're related rather than identical (e.g.: "the pituitary gland is controlled by the hypothalamus via releasing hormones and it secretes tropic hormones" (pg. 396)). So are they identical? And if not, what distinguishes between them?


texts: Are there beneficial genetic mutations identified by consumer DNA genotyping?

texts:
I'm looking at services like 23andme, and see that they identify a wide variety of genetic-based risks, like predisposition to diseases, hair loss, cancer, etc.

Are there a more "positive" DNA analysis outcomes out there? Like increased strength, cheerfulness(resistance to depression), etc?


texts:
So this one is found in white mountain forest in New Hampshire, and I have strong suspicion it is actually just a boletus.

My question would be what's is the name of this fungus?


texts:
I have been swimming in the seas around Minorca and saw a jellyfish I had not seen before.

I have tried to find it and have (eventually) found 1 single picture of the jellyfish.

The problem I have is, the image is from one of these "buy our picture" website and offers no information about the creature.

What type of Jellyfish is this and can I assume from the picture that it does not actually sting humans?

I have researched, and viewed sites like (As well as Google/Bing images)

http://www.holidays-majorca.co.uk/trips/beaches/types-jellyfish-around-majorca
http://www.seafriends.org.nz/indepth/jellyfish.htm (I know, it's NZ but I'm looking everywhere I can)
http://www.glaucus.org.uk/Moonjell.htm
http://www.whatsthatfish.com/browse/tags/limit/Jellyfish
http://www.imenorca.com/en/entrada-de-blog/jellyfish-minorca
http://www.menorca-tips.com/EN-jellyfish.html
http://www.mcsuk.org/downloads/wildlife/Jellyfishguide.pdf


texts: Do ant pheromones indicate the direction to go?

texts:
I know that ants communicate with pheromones but I am wondering if these pheromones can indicate in which direction to go. For example the ants leave pheromones to indicate a food source and when they find food they eventually create a "highway" of ants running to the food.

If I disturb the ants while they're going to the food source in such way that they don't know anymore in which direction is the food will they choose a direction randomly (nest or food) or will the pheromones also indicate in which way to go to get the food?


texts:
I recently read that cucumber skin is an effective repellent for some ants:

Set out cucumber peels or slices in the kitchen or at the ants' point of entry. Many ants have a natural aversion to cucumber. Bitter cucumbers work best.
Source: Natural Insect Pest Control

See also: How to Use Cucumbers to Prevent Ants from Entering the Home
But when I tried it out they died instead. What made this happen?


texts: Why do we spend so much time on creating taxonomies?

texts: I spent 3 years building a taxonomic database of plant specimens for the Missouri Botanical Gardens (http://www.tropicos.org/). Myself and two other programmers used a modern database and web pages to share the specimens with the research community. Last I looked there are over 3 million specimens included. Anyway I never got a straight answer as to why there is so much time, money and botanist's lives spent categorizing the earth's flora. What is the end goal here? I'm hoping there are professional scientists here that do taxonomic work that can chime in. Thanks.


texts: Does the source of caffeine affect the biological impact?

texts:
I've recently decided to give up my morning coffee in lieu of a caffeine pill. Both are around 200mg (my Tim Horton's XL 4x4 was 240 mg of caffeine) of caffeine. We were talking about the various impacts this has on my body (for example, I now need a different source of the whopping 680 calories the beverage used to give me) and one thing that came up was that the caffeine pill would be more damaging to my liver.

I was resistant to their claims, since they were simply basing it off what they heard in college from various health advisers, but three people from different backgrounds all concurred that the pills would be more harmful to my liver in spite of the the fact that there's a decreased quantity.

The points to their argument were:

The concentration of caffeine pills is greater than that of the coffee.
The caffeine in the pill is synthetic, and thus harder for the liver to process.

My counter to those points were that the tablet takes longer to dissolve than the coffee which I'd expect go straight into my bloodstream. (And in fact, I notice it takes longer to get the kick from the pill, and it lasts longer, which would be consistent with my counterpoint). As far as synthetic, I was under the impression a chemical is a chemical, that's what's so great about chemicals.

I understand that changing from coffee to pills will have some sideeffects (less antioxidants, a need to replace the sugars I had before, etc). But my question isn't around those - it's specifically around whether the effects on the organs (emphasis on the liver) are different when caffeine in similar dosages is delivered via a pill as opposed to a brewed liquid. Other comments (as opposed to answers) are welcome, as I would not blindly ignore wise consul, but I would appreciate if answers focused on the question.


texts: Which amino acids can be phosphorylated?

texts: Definitely serine, tyrosine, and threonine. What about aspartate and glutamate? I thought the O- on the carboxylic acid side group could be phosphorylated but am getting mixed responses to this. Any thoughts / any other amino acids I'm missing?


texts:
So for the last few days I have been noticing these small bugs in my bathroom -- they don't appear frequently, and I see them once or twice a month.
The characteristics and behavior I observed are as follows :

They RARELY move around.
They are extremely flat, like totally flat
Some are small, some are big (but still the overall size is small)

Below are the pictures :

I cropped this picture since the original size was 5mbs and the limit was only 2. If anyone wants the original image I can inbox them .

Appreciate any help or suggestion with this :)

EDIT 2
I am adding another image for greater clarity , hope this helps

Edit 3

Location: Karachi Pakistan.

Size: 0.2-0.4 cm

As for nearby animal populations: No not much, just the usual street cats.

For a few months these bugs were gone until recently they have started to appear in the bathroom, like I see them 2-3x a month just sitting still for hours and hours.


texts: Some statistics say that on earth there are approximately 5500 mammal species.I have seen a video of Mother Cape Buffalo protecting it's calf from being eaten by predative animals.Like Mother Cape Buffalo,do remaining mammal mother species also try to protect their babies from being eaten by predative animals?


texts: "Twig-with-leaf"-like insect in central Mexico

texts:
What's that?! I have googled around and found insects that looks like a twig, and others that look like a leaf, but this one looks deceptively like a leaf at the end of a twig (I swear it's a real living thing despite the appearances: it has legs and moves around!). As you can see from my hand on the photo it is also fairly big (well, at least for my European standards...).

Location: Morelia, Mexico (about 2000m high, in the tropics)
Time: October (humid season), in the morning


texts: All winged vertebrates have wings which are homologous to each other and to the forelimbs of the non-winged vertebrates. But what about insect wings? Are all insect wings homologous, and are there any homologies between insect wings and any vertebrate limbs?


texts: Question regarding research project on indigenous ants during Eastern European winter

texts:
I am by no means biologist (I'm a programmer), but I want to make an experiment that involve the participation of ants. So please excuse my ignorance on the subject and my potentially uninformed questions.

I need to find some ants, but it's fall/winter here in Eastern Europe, so it seems that I won't be able to find in the wild. So my questions are:

If I find a species that is local (meaning that it's used to live through winter - maybe entering some kind of lethargy?) is it just putting them in high temperature enough to get them out of this mode?
Probably depends on the species, but if I take just few individual workers without a queen, and provide them with food, is it possible for them to live without a queen? Clearly they won't reproduce so their "colony" will disappear, but are the individuals able to live for a while without a queen?


texts: Separation of sister chromatids diring anaphase without Centrosomes in plant cell during mitosis

texts: As in animal cell during mitosis sister chromatids are separated from each other during Anaphase by the pulling of kinetochore fibers toward their originating poles of centrosomes but as we know that Plant cells lack centrosome or centrioles then how sister chromatids are separated in plant cells from each other?


texts: Do antisense transcripts have different names than their sense strand transcripts?

texts: I want to find which genes in the human genome can potentially be complementary to a transcript that could act as antisense transcript inhibtion? Are cis-NATs (naturally occuring anti-sense transcripts) considered different transcripts and named differently or do they have the same name as the sense transcript?


texts: Why is that bonobos skin color on the areas not covered by hair are dark throughout life unlike the chimpanzee?


texts: what is this mushroom and how to grow this mushroom?

texts:
What is this mushroom?

And how to grow this?


texts: Which type of RNA molecule is coded for in intergenic regions? I think it must be a non-coding RNA but I'm unsure which type.


texts: Simultaneously using both hands - How does that work?

texts:
Is some part in one hemisphere the decision maker and "calling the shots" - controlling the opposite side's hand "directly" and controlling its own side's hand through the corpus callosum. Or: is there some "Gestalt" of parts in both hemispheres working as one making the decision?

If the latter - it would seem counter intuitive to have a deciding part which is not "unified" in one region, having to go back and forth through the corpus callosum for deciding.


texts: How do I effectively visualize data showing change in a lot of samples over two time periods?

texts:
I've tallied the number of glands in a plant this year and last year. My full data set has about 20 plants in it (I've reproduced the data from 10 of the plants here). I want to show that the plants this year have had consistently lower gland counts than they did last year, but I don't want to bog readers down with too many data points in their faces. What kind of graph/chart should I use to best show this trend?

        Gland Count
PlantID  2015    2016
1        22.92   19.50
2        11.67   7.12
3        19.67   15.33
4        22.33   12.00
5        20.92   18.58
6        25.83   23.83
7        25.67   32.17
8        22.83   17.00
9        28.42   26.25
10       17.92   16.92


texts: Infinite site model and Watterson's Estimator

texts: Why is it that under migration, the watterson's estimator (theta) is upward biased? What does upward bias means? And why do we have downward bias under exponential growth? Lastly, is it only the watterson's estimator whose variance would decrease with increasing recombination rate or would the tajima's estimator's variance would decrease too?


texts: Recombination-based vs. Sequence-based genetic mapping

texts:
Now that sequencing is becoming increasingly cheap, what is the value of recombination-based genetic mapping against the sequence-based genetic mapping?

I think that in the past recombination-based genetic maps were used as blueprints for sequencing projects. But since now the entire genome can be sequenced pretty cheaply both in time and money, what is the unique value of recombination-based genetic mapping?

One thing that comes to mind but I am not very sure. It might be suitable for mapping novel phenotypic markers e.g., unmapped diseases.


texts: Do camels pose an environmental threat to kangaroos?

texts:
Camels, once used for transport across the Australian outback, were set free, and are reproducing at an uncontrolled rate in the empty interior of Australia.

Do the ecosystems of camels and kangaroos overlap?

Are camels competing with kangaroos for what little vegetation there is, and if so, what is the impact on kangaroo demography?


texts: Found in Russia in the kitchen. It is about 3 mm long.


texts: Why do we assume that the first humans were dark-skinned?

texts:
According to the article Dark skin and blue eyes: How Europeans once looked:

  It is widely accepted that Man's oldest common forefather was dark
  skinned, and that people became more pale as they moved further north
  out of Africa into colder climates with less sunlight.

I thought that humans' oldest common ancestor was light-skinned, because

Dark-skinned people have white palms and soles, but light-skinned people have more consistent skin tones. This suggests that light skin is more ancestral and dark skin evolved to protect skin from the sun.
Bonobo chimpanzees, our closest primate cousins, look like they have light skin under black hair.

I understand we all originate in Africa, but I thought that the environmental conditions in Africa were different from today. How do we know that the first humans were dark-skinned?


texts: Difference between the P4 and P5 subtypes of P-type ATPases in plants

texts: In plants there are various kinds of P-type ATPases. What is difference between P4-ATPase and P5-ATPase?