texts: Do patella bones form in people born with the inability to walk?

texts:
The patella is a sesamoid bone that typically doesn't completely from and ossify until ~3-6 years of age (e.g., Source). My long-standing understanding (supported by a claim in Saladin's college A&P textbook1 sitting on my shelf) was that sesamoid bones form "in response to stress."
Well, I had a student in my anatomy class this morning ask me the titular question about people born with leg paralyses or other congenital issues preventing them form walking. To their point, if such congenitally paralyzed people never walk and therefore never place stress on the knee via the quad tendon, would they ever form a sesamoid bone (i.e., the patella) in the knee?
I've done some digging and found evidence of "nail patella syndrome" (e.g., here) which results in people not forming a complete patella. However, I was unable to quickly narrow down any sources discussing lack of patellar growth due to congenital leg paralysis.

1.  Saladin, K. S. 2015. Anatomy & Physiology: The Unity of form and function. 7th edition. McGrawHill, Education, New York, NY


texts: When something "smells moldy" what are we really smelling?

texts:
When things smell moldy --  it could be clean clothes left in a heap, a damp basement, old books stored in elevated humidity -- they can smell moldy.

There are distinct smells for each of these.

Are we smelling the mold spores themselves, or are there other molecules released by molds that causes the "moldy smell" we perceive?


texts: Did Plant Cells Evolve from Animal, Protist, or Fungal Cells?

texts: I know protists and animals preceded plants but I am unaware of when fungi arose in relation to plants. At the moment, I cannot find a resource stating how plants evolved from existing kingdoms, or whether they evolved independently from prokaryotes. Thanks for the help, sorry if this is common knowledge.


texts: What disease / parasite / fungi has affected the mango in the picture?

texts: The mango is found to have some kind of fungi / worm on it's surface . This has affected a huge number of mangoes in the same tree . It can be described as white and fibrous / weblike structure near the top of the mango .


texts: Are any biology research journals free to publish in?

texts: The research journals Ive published in require significant financial cost to publish. On top of that many require a membership to the society the journal is associated with, in addition to publication fees. I was wondering if anyone is familiar with any journals (reputable hopefully) that do not require fees like this to publish a research article?


texts:
A normal human body has approximately 3 billion base pairs. Given that humans have 10 trillion cells, how is that the number of base pairs of DNA is less than the number of cells? It can happen only if most of these cells don't have DNA, or have I misunderstand the topic?

Can you give an account of why the number of cells exceeds the number of DNA base pairs significantly? Isn't it logical to have more DNA base pairs than the number of cells?


texts: What kind of spider is this? (Photo included)

texts: We found this guy on the ceiling inside today. We live by Lake Erie in Ohio so we see a lot of large spiders, but this one looks different than most we encounter. It's was about the size of a quarter (~ 25 mm), and the abdomen was iridescent.


texts:
According to wikipedia and Human Parasitology
By Burton Jerome Bogitsh, Clint Earl Carter, Thomas N. Oeltmann

  Phoresis: In this type of symbiotic relationship, the phoront, usually the smaller organism, is mechanically carried by the other,usually larger organism the host.

So can the host acting as a carrier be called a mechanical vector?

On searching google.books I found some books mentioning:

Like Clinical parasitology

  Hosts that transmit parasites to man are vectors. Those that are essential in the life cycle are biologic vectors; those that are not essential are phoretic or mechanical vectors.


texts: Why and how does uniprot list around 150,000 proteins in the human genome?

texts: Using organism:"Homo sapiens (Human) [9606]" as a query in uniprot returns about 146,000 proteins. I was under the impression that there were only 20-25,000 protein coding genes in the human genome. Is this something to do with splice isoforms, like those from SpliceProt, or another splice isoform database or tool?


texts:
I was wondering if we could think about experiments to falsify natural selection . According to this wiki : we could invalidate natural selection

  “...if it could be shown that selection or environmental pressures do not
  favor the reproductive success of better adapted individuals”.

So, to test this hypothesis we would have to:

Have different individuals that are defined as more or less adapted to a given environment
Put them in that environment
See if the better adapted individuals have a better reproductive success. (I will avoid the word fitness because one can consider it already contains the principle of natural selection)

But is it possible to define a priori that an individual is more or less adapted? Of course, we could suppose a priori that because of some or other trait (higher longevity, higher stress tolerance, or whatever), an individual carrying that trait will be more adapted. But if we find out this individual does not have a better reproductive success in that environment, we could conclude it was just not the right trait to be better adapted and it would not invalidate natural selection.

Isn’t it, on the contrary, the fact that some individuals have a better reproductive success which allows defining them as better adapted a posteriori? There would then be some kind of a vicious circle.

Ok, so one could say that we do not need to define a priori better or less adapted individuals. We could just put individuals in an environment and see if at least some have a better reproductive success. That would mean that they are better adapted –and so that natural selection occurs-. But suppose we find no significant differences in individuals reproductive success: that could indeed mean that natural selection does not exist. But, well, that could also just mean that there was no selection pressure in that environment.

So if we want to test natural selection existence, we need either to get individuals that are a 100% sure better adapted than others; or environmental conditions that 100% sure exert selection pressures on organisms ; and we need to know this a priori. But, it seems to me that considering an individual as “adapted” or an environment as “selective” can only be done a posteriori if we already accept the idea of natural selection.

That’s why, to me, it is difficult to think of an experiment that would falsify natural selection. Is natural selection falsifiable ?


texts:
Why do we call the vascular bundles in plant leaves "veins"? I think its probably because the xylem and pholem serve circulatory function analogous to the human body's circulatory system with arteries and veins. But why don't we call the vascular bundles arteries instead or veins?

In the human body, we call a blood vessel "vein" when it travels blood to the heart and an "artery" when a blood vessel travels blood away from the heart. Is there a similar reason or significance as to why we call vascular bundles "veins" instead of "arteries"?


texts: How are proteins containing other elements encoded?

texts: If I understand correctly, proteins are formed by associating each three-letter DNA sequence  to a certain amino acid. Yet there seem to be proteins which contain elements such as copper, which isn't present in any of the amino acids. How are these encoded?


texts: Phospholipid Bilayer structural reversal

texts: What would happen if the phospholipids in the phospholipid bi-layer were reversed, the fatty acid tails now facing outwards and the phosphate heads facing inwards? I'm assuming this will not affect the protein channels, but perhaps the loss of cholesterol in the structure of the bi-layer. Would this then mean that the fluid mosaic model no longer holds?


texts: Don't understand how multiple replication bubbles work

texts:
I'm not exactly sure how multiple replication bubbles work, assuming were working with a linear, eukaryotic chromosome.

This is a diagram for reference:

It appears that the DNA is being synthesized "towards" the centre. What I mean is that in one replication bubble, the top strand is being replicated from left to right, whereas for the other replication bubble, the top strand is being replicated from right to left.

I don't understand why this is. Aren't the directions reversed? Isn't synthesis always supposed to be from 5' to 3'?

Thanks!


texts: How can DNA replication result in hair pin structures?

texts: My professor said that one of the reasons SSB proteins are so important was to prevent the formation of hair pin structures, I can't see how or why DNA would form hairpin structures and there's not much about it on the internet so can anybody explain this hair pin thing and how SSB proteins prevent it from happening ?


texts: For how long can a raven stay airborne (a week or more)?

texts:
I'm wondering for how long a raven can stay continuously airborne, if strained to do so? If it makes a difference, I'm mostly interested in the Common raven, Corvus corax. Are there for instance any information on long-distance dispersal (wind-blown individuals over sea?) that can be used to roughly estimate this? Information on other corvid species could also be interesting, as a rough proxy.

If you are wondering, my motivation for asking is the biblical story in Genesis 6–8 (the deluge of Noah). Here, Noah sends out a raven and a dove to look for land. From the story it appears as if the raven can stay airborne for a longer time than the dove, which returns to the ark to rest. Is there any realism in the claim that a raven can stay airborne for one or maybe even two weeks?

Some background from Genesis 8 (this translation):

  After forty days, Noah opened the window he had made in the ark. He sent out the raven, and it departed. It went back and forth until the water had dried up from the land's surface. He then sent out the dove to see if the water had subsided from the land's surface. The dove could not find any place to rest its feet, and it returned to him, to the ark. There was still water over all the earth's surface. [Noah] stretched out his hand, and brought it to him in the ark. He waited another seven days, and once again sent the dove out from the ark. The dove returned to him toward evening, and there was a freshly-plucked olive leaf in its beak. Noah then knew that the water had subsided from the earth. He waited yet another seven days and sent out the dove [again]. This time it did not return to him any more.

So the raven couldn't find a place to land, and it flew around until it could do so. A week later, the dove still couldn't find a place to land, but a week later it could. Thus, either (a) the raven was flying around for more than a week (as much as two weeks) or (b) the raven could more readily land in a wet area than the dove. Can either of these be true?


texts:
So I am taking an introductory Biology Course and I was recently introduced to the idea of Hardy Weinberg Equilibrium. I wanted to find out why exactly we calculate the frequencies of alleles in the next population using the law of multiplication.

For example,

In a hypothetical population of let's say 300 civets, 20% of the gene pool codes for blue eye color and the remaining 80% codes for black eye color. It is given that blue eye color is recessive.

300 civets = 600 alleles total
80% code for black eye color = 480 alleles
 20% code for blue eye color = 120 alleles

When we calculate the frequencies of the next population we basically say what is the probability a given offspring will this pair of alleles. Following the example above, I would argue that the probability an offspring has two blue eye color alleles is (120/600) * (119/600). However, my textbook says that it is (120/600) * (120/600) = 0.04 but doesn't that assume replacement of alleles! My only rationale is that as the population tends towards infinity the difference becomes negligible.

Am I right?


texts:
According to my book- red blood cells have the ability to concentrate hemoglobin in the cell fluid upto about 34g in each 100 ml of cells.The concentration does not rise above this value because this is the metabolic limit of cell's hemoglobin-forming mechanism.
Furthermore, In normal people,the percentage of hemoglobin is almost always near the maximum In each cell.
The next statement says- the quantity of hemoglobin in each respective cell contains an average of 15g of hemoglobin per 100ml.
So what is the actual concentration of hemoglobin in 100 ml of blood?


texts:
To quote Goodman & Gilman :

  An alternative way of defining the anesthetic state is to consider it
  as a collection of “component” changes in behavior or perception. The
  components of the anesthetic state include:
  • amnesia
  • immobility in
  response to noxious stimulation
  • attenuation of autonomic responses
  to noxious stimulation
  • analgesia
  • unconsciousness

My question is, does not the state of Unconsciousness already imply other components of analgesia and amnesia? Analgesia is the absence of the perception of pain, which is granted if there is unconsciousness which would be the absence of all perceptions.

I am not certain if unconsciousness also entails amnesia, but it seems that remembering what happened when unconscious seems considerably unlikely.

Apart from a reductionist argument for minimizing the constraints required for classification as a general anesthetic, I am more interested in cases where unconsciousness would be achieved without analgesia or amnesia, which could be a likely rationale behind including the additional caveats in the definition.


texts: Did the hyoid bone of Australipetichus afarensis have a hyoid bulla?

texts: The hyoid bulla is present in Chimpanzee hyoid bones, and not in Humans. Does A. afarensis have a hyoid bulla?


texts:
The survival curve/function describes the probability of a given individual to survive to age $x$. In humans, today's survival function is very much influenced by medicine. This leads me to wonder what the survival function looked like before modern medicine. Typically I wonder what the survival function looked like during the paleolithic age.

What did the survival function looked like during the paleolithic age?

Why did the survival function looked like that? What were the major causes of mortality for males and for females?


texts: I found this dude hanging out in my sink, but he didn't fly away when I put a dish in the sink. Turned out it was dead. The front part looks exactly like a housefly. But, I've never seen the back end (abdomen) look like this. Any ideas?


texts: Is there enough vitamin B12 in lakes, rivers and ponds, for humans not to need to take supplements?

texts: Vegans will often say that having an animal-free diet is best for our health and is actually the diet that humans should be eating to function optimally. To which meat eaters will raise the issue of B12, and how (they believe) it is only to be found in animal products [thus vouching for an evolutionary need to eat meat and eggs). These days, with all our water being treated to remove pathogens, it is obviously best to take b12 supplements, but the question remains: do vegans have a point? Is there actually enough b12 in water for humans to not develop an insufficiency?


texts: What promoter is required for expression of a human protein Y in bacteria?

texts:
This is the actual question. It's from an entrance test for a research institute:

A scientist wants to express human protein Y in bacteria. For effective expression of this protein he should use
(A) promoter of human gene Y. (I think this is the correct one)
(B) promoter of bacterial gene.
(C) operator of any human gene.
(D) operator of any bacterial gene.

I think my answer is right although I am not sure if my thinking is entirely correct.


texts: How is haemophilia dominant in human females?

texts:
In human females one X chromosome is inactivated forming a Barr Body. Then how is it that haemophilia is dominant?

Suppose a female has one normal X chromosome and one chromosome with the haemophilia gene. Now suppose that the normal X chromosome is inactivated — will the female show haemophilia?


texts: Are the bacteria doing the same photosynthesis as plants do?

texts:
I mean Plants during photosynthesis produce  oxygen but Do bacteria also produce oxygen during photosynthesis or produce  other gases?

If yes , how do these bacteria process photosynthesis by producing other gases?


texts: Age until physical growth ceases, mammals

texts: Fairly basic, but I am seeking a table showing how many years from birth it takes for the best-known mammals to stop growing.  (Including the latest on humans - ie. 0-17..?).


texts: Is eating cooked food an evolved behavior or rather an intelligent one, passed down via culture?

texts:
I was just eating a rather rare steak when I started wondering whether eating foods cooked was something I would instinctively want to do if the practice hadn't been taught to me.

So, is cooking food an evolved behavior, inspired by nutritional value or health benefits, or is it a practice learned, and passed down through culture alone?


texts: Is a pampa an example of ecological succession?

texts:
I'm not very sure if a pampa is an example of an ecological succession.
The reason of my doubt is due I've remember hearing that a Pampa is formed when a Valley which has had a river on it, no longer has it due the river changed its course and left the place without water.
But is it okay for this reason to imply that the Pampa (biome) is the result of an ecological succession?. The wikipedia entry doesn't give much details.
But it constrains the term for only the lands located in Brazil and Uruguay. It does not give any indication why some other places such as in Bolivia and Peru also use the term. Given these, could it be confused with a Mediterranean forest or with a Chaparral?.
Are those of the same origin?. Can someone help me here?. I'm confused about these.


texts: Examples of how the presence or absence 2'-hydroxyl groups influence physicochemical properties of DNA and RNA

texts:
I know, for instance, that RNA is much more succetible to alkaline hydrolysis than DNA and this difference is determined by the presence of 2'-hydroxyl group in ribose.
I have also heard that "DNA is more stable" and thus was selected as the repository of genetic information. Though, I still haven't understood why the lack of just one hydroxyl would lead to more stability...


texts: How does isopropyl alcohol disinfect less in higher concentration?

texts:
Isopropyl alcohol (2-propanol) can be used as disinfectant.

For increasing concentration of it in water, the effect as disinfectant increases, and then decreases again.

Typical concentrations for use as disinfectant seem to be 60-75% isopropyl alcohol in water.

Wikipedia: Isopropyl alcohol - Medical mentions membrane pores of bacteria that will not open without water.

That does not feel like the full explanation to me; I expect there are bacteria with membrane pores of diverse kind.
Does 100% isopropyl alcohol not disinfect at all - or just more slowly? What abour the effect on other pathogens?


texts: Will ammonia continue to accumulate in an aquarium tank if a strong antibacterial or chlorine is added to the water?

texts:
I've always wondered what would happen if dead plants and fecal matter lay in chlorinated waters and/or waters treated with strong antibacterials or antibiotics.

I've heard that aquarium tanks owners warn against using strong antibiotics as it can kill nitrifying bacteria which convert toxic ammonia to a safer form of nitrate. Otherwise, ammonia levels can buildup and be toxic to the aquatic life in the tank.

However, that doesn't make sense to me. Even if the nitrifying bacteria die, wouldn't the ammonifying bacteria which produce ammonia in the first place also die? Would there be greater amounts of ammonia in the water after these agents are repeatedly used, or would ammonia levels with nitrate levels together fall significantly?


texts: I want to do an assay to see, if an ordered enzyme is active or not. It's a glucosyltransferase from S. mutans which hydrolyses sucrose into fructose and glucose. It then connects the glucose-monomers to dextran. Our idea is to detect the free fructose. There are many tests for this, for example the Fehling-Test or the Tollen-Test. The trouble is, that they have to be heated on a waterbath - I think that's very suitable for microwell-plates. Maybe someone here has a better idea how to measure the enzyme's activity?


texts: What is the meaning of the following: " completion of open rounds of DNA replication"?

texts: I am studying a paper about the relation between polyP granule and cell cycle exit. As the author explained the four general steps for cell cycle exit, the second step is" the completion of open rounds of DNA replication". But I really can't figure out the meaning of this sentence. I hope that someone can explain this to me. Thank you!


texts: Did the number of rods changed from ancient time?

texts:
Correct me if I am wrong, but I know that rods work under limited light conditions only.

But now we are in a world that always have lights everywhere unlike ancient time when humans had to deal with darkness.

I also know that the humans adapt to its living conditions.

Since our eye only uses the cones and don't use rods often, will the number of rods decrease because of this?


texts:
I'm looking to use the software DIYABC 2.1.0 to apply approximate bayesian computing (ABC) to some resequenced data that I have.

The resequenced data is in FASTA format however, and the software requires an SNP datafile format (.snp). How do I generate such a file from FASTA formatted data? Is it possible?


texts: Why is it possible to calculate the equilibrium potential of an ion using the Nernst equation from empirical measurements in the cell at rest?

texts:
In trying to understand the Nernst and GHK equations, I've hit upon a snag somewhere deep in my understanding of the subject matter.

Scenario 1: when calculating the membrane potential of a living cell at rest we use the Goldman equation. This requires us to measure both the concentrations of the ions and the membrane's permeability to said ions, at rest (at least for the concentrations).

Scenario 2: given two cells separated by a membrane (as in Figure 3 here), with a different concentration of KCl in each cell, and having the membrane permeable only to K ions, we can compute the equilibrium membrane potential using the concentrations of the K ions - after the system has reached equilibrium.

So far so good. Here's my question:

Given a living cell at rest with all its ion concentrations, the Nernst equation is used to compute the equilibrium potential of a single ion, using the concentrations at rest. Why is this allowed? As I understand it, the concentrations as measured are what the cell "decides" them to be - it can change the permeabilities of the channels, or create more pumps, etc. - and then we'll measure different ion concentrations at rest. And these concentrations will change if a cell decides to open or close some channels (which is what happens to create the action potential). But the concentrations that are used as input for Nernst's equations should be measured at the actual, not just the steady state, equilibrium (right?).

So, why can we use the steady state measurements to derive the equilibrium potentials?


texts: At what point in the day do plants start to absorb light for photosynthesis?

texts:
My plants sit on a small table in my only window, facing Northwest. They are thriving. They are obviously getting enough indirect light to survive year round. Maybe they have adapted?  They have never really been in direct sunlight.

At what point in the day do they start absorbing this light?
Also, if the sun has risen behind my apartment building on a dull January morning and the sky is light are they reaping any benefits yet?

My plants are:

an asparagus fern with a small grapefruit tree in a tall open terrarium
an African violet
an aloe vera plant
2 sprouting avocado seeds
a small house palm.

I live in Alberta, Canada near the 49th parallel. This is a very sunny part of the province. Your ponderances will be welcome.


texts: Can Fluoride be absorbed into the blood from within the mouth without swallowing?

texts:
I'm having a discussion with somebody regarding Fluoride usage. I told him that even if he doesn't like the idea of ingesting it, brushing and spitting it out will do you no harm. He then said this:

You have missed the point of ingestion massively! Brushing with fluoridated paste is NOT fine.
The mouth, with its gum entry and under tongue glands are the PERFECT entry point to the blood, without even swallowing? What do you think oil pulling is all about? Fluoride passes those barriers as easy as the shit that resides in your blood can!"

Now I call BS on this, but I'd just like an expert opinion with cited sources if possible. Can Fluoride be absorbed purely by the mouth without ingestion?


texts:
DNA is made up of pairs on AT and GC base pairs.

I know that A only pairs with T and G only with C. Does this apply just to humans, or are there animals where T will pair with G?

Also, surely there would be more possible combinations if A could pair with G or T or C, and DNA would have a better information density - less would be needed to hold the information?


texts: How do major and minor grooves arise in the DNA helix?

texts: I understand that they arise due to the pairing of bases of two opposite stands and are sites through which important proteins needed for replication and transcription of DNA interact. But I don't get how the arrangement of bases really generate the grooves.


texts: Is there a Reverse Transcription optimization for long, 9kb, transcripts?

texts: Has anyone optimized RT for long transcripts (9kb)? The downstream application will be PCR amplification and Illumina library prep.  It will be trivial to make internal primers sets for the PCR that are specific as long as there are no chimeric sequences.  If there are, they will probably get primed also.  If anyone knows of an optimization and/or other potential pitfalls, I would love to hear them.


texts: I've been trying to model a non-coding RNA molecule which binds to a RNA binding protein. I found the DNA sequence for ncRNA from NCBI. I did not find the RNA seq of the same. Hence my doubt is, whether we should take the DNA seq and convert all the thymidine to uridine and then take that sequence for RNA modelling. Also, I wanted know if there is any kind of splicing occurring in case of ncRNA formation. Thank you in Advance.


texts:
If a woman has FEVR and is affected by the disease, what are the chances of her passing the disease to future generations. I read somewhere from a credible source like NIH(I couldn't find the link again, I am attaching another https://rarediseases.info.nih.gov/diseases/1613/familial-exudative-vitreoretinopathy#:~:text=Familial%20exudative%20vitreoretinopathy%20(FEVR)%20is,the%20blood%20supply%20to%20retina.), that the babies that the woman conceives could be affected by or carrying the FEVR causing genes, or may neither be carrying nor affected by them. Depending on the type of inheritance, which are autosomal dominant, autosomal recessive, or X-linked recessive, the chances of having a normal baby vary. The chances of having a healthy kid for autosomal dominant and autosomal recessive are 50% and 25%, respectively ( I am intentionally excluding the possibility of X-linked recession).
Therefore, if the inheritance is autosomal dominant, then, there is a 50% chance that the baby is healthy and not carrying the genes. And the successive generations created by the baby will not have the gene causing FEVR. Is my understanding correct?


texts:
How is 16s rRNA used to identify unknown bacteria?

With PCR the 16S rRNA is amplified and sequenced, but how can you identify the bacteria with this 'piece of knowledge' if the 16S rRNA is conserved and so the same in all bacteria?


texts: What, if any, diseases do larder beetles carry?

texts:
I found one of these beetles on my bed as I was attempting to get in. I'm 80% sure my cat carried it in (I found it in the exact same space he had been sitting ten minutes previously).

My question is what, if any, diseases do these bugs carry? It did not bite me, though it may have bitten my cat. I'm more worried about bacteria etc that it may have carried around my bed/room. Can they transmit salmonella? Should I break out the disinfectant, or is it no big deal?

I have researched them as best I can, and I found someone noting that they can spread bacteria, but found nothing on how severe it is. For example, my cat obviously spreads bacteria, but I let him on my bed without worry. I have never see one of these beetles before.

I have a secondary question, if that's allowed - what are the chances it laid eggs on my bed? It was there for possibly 4-5 hours if my cat indeed carried it in. I have rodents (pets) in my room and am peripherally worried about an infestation happening.

For context, I live in the center of the UK.


texts: Endocannabinoid Transporters - which ones are Likely to Exist and what is the Evidence for their Respective Existence?

texts:
Endocananbinoid = Endogenous Cannabinoid or CB1 and CB2 ligands.

I'm asking which endocannabinoid transporters exist and could the one answering show all the evidence for the existence of the transporters they mention. For instance anandamide is suspected to have a transporter and there is some evidence for its existence, and paracetamol's chief active metabolite, AM404, appears to work by inhibiting the actions of the anandamide transporter.


texts: How large is the immune repetoire and at what age does it finalize?

texts:
There seems to be a large disconnect between the Wikipedia's article on the immune effector repetoire and Janeway's Immunobiology 9th Edition, a standard textbook widely used to teach immunology to pre-meds. In the Wikipedia it puts the size of the repetoire at 100,000 unique receptors, but in Janeways it says the repetoire has typically 10^8 or between 100 million and 1 billion receptors. Also, in Janeways it implies that the repetoire is largely finalized at some point, although it gives no specific age, but in the Wikpedia article it claims that new T cells are constantly developed by the body throughout a person's lifetime.

How many unique T-cell receptors typically circulate in the body at one time and at what age is the immune repetoire largely decided (if any)?


texts:
I have seen a Discovery Channel video of a bird throwing stones in a pot to raise the water level so it is able to reach and drink it.

A similar experiment in this paper from Current Biology shows the same phenomenon under controlled conditions, and is documented in this video.

This clearly illustrates how intelligent these animals are may well be more intelligent than many mammals. For example, the regular domestic dog will definitely not push stones in a bucket of water to quench his thirst.

How did crows, and perhaps birds in general, became so intelligent, and even more intelligent than many mammalian species?


texts:
I was writing some code scripts to analyze some plasmodium spp. using this database. However the names assigned to the various epitopes and other items on the list is very very very disorganized. In some places there are acronyms and other places the full name. Sometimes hyphens replace the spaces for the same epitope name. So I was trying to collect lists of all the different names that are actually synonyms of each other. However there were some words that were added on sometimes that I wasn't sure would count as synonyms:

"xxx" and "xxx, putative" synonyms?
"xxx" and "xxx like antigen" synonyms? (this one made little sense to me as both are epitopes
"xxx" and "xxx 1" synonyms?
"xxx" and "xxx partial" close enough to    be synonyms for sake of
grouping?

I'm rather new at analyzing these sorts of databases. I'm sure I'll find other such messy naming issues and was wondering how to approach such a problem and solve such discrepancies.


texts:
I'm writing a lab on sexual dimorphism (sex differences in phenotypic traits) and I want to include a sentence in the abstract that states how prevalent sexual dimorphism is. However, I can't find any figures that pertain to organisms generally (or even for a clade).

How prevalent is sexual dimorphism in nature? How frequent is sexual dimorphism beyond primary sexual traits (gonads, gametes etc.)?


texts: How does hypochlorous acid inactivate viruses?

texts: I was reading how bleach was used very widely as a disinfecting agent during the 2014 West Africa ebola outbreak and am interested in the mechanisms with which hypochlorous acid inactivates viruses. Most of the studies I could find only focused on its activity against bacteria. I know viruses tend to be much more difficult to inactivate than cells as they're somewhat simpler and aren't really alive.


texts:
Are there pre-synaptic alpha 2 receptors in the post-ganglionic synapses of the heart?

I haven't found any sources that clearly state whether they do or not. I'm also not sure if they exist in most post-ganglionic synapses, or if they do in just specific ones. The reason I ask is wanting to understand the reflex tachycardia non-selective alpha blockers like phenoxybenzamine cause.

One of the side effects of phenoxybenzamine is reflex tachycardia, caused by, from my understanding, partly a reflex to the initially decreased blood pressure and due to the blocking of alpha 2 receptors, increasing nor-adrenaline release. Does this occur by :

Blocking alpha 2 receptors at other sites, causing increased blood levels of nor-adrenaline, which then cause increased heart rate.

OR

Blocking alpha 2 receptors in the heart, increasing local increase of nor-adrenaline?


texts: house keeping gene variation under treatment

texts:
I am injecting BCG in mice ears to measure the local inflamation response in the infection side, one ear in the same mouse is kept as control by injecting PBS, in the other one, BCG is injected. When I do a qPCR the house keeping gene comes out later in the BCG ears compared to PBS control (even I measure RNA and DNA concentrations to have the same amount of materia). Does it means I have less amount of material in the PBS injected ear? or could it be the expression of the house-keeping gene is afected by BCG infection? Any other ideas?

Thanks


texts:
After we have eaten, we feel cold and sleepy. I think it's because the maximum blood supply is transferred towards the digestive system so that digestion is done, and therefore the brain to does not get adequate blood supply. Am i right about this?

Also, why do they suggest to take a short walk after dinner especially?


texts: Neomycin resistance gene in E. coli stb3 cells

texts:
We use a lentivirus packaging vector called pLenti_puro_DEST. We use puromycin to select for the cloned gene in 293T cells. However, the pLenti_Neo_Dest has been discontinued, so I'm cloning a Neomycin resistance gene into the pLenti_Puro_Dest thus replacing Puromycin with Neomycin. I usually just grow up this gene in Stb3 or Stb4 cells from invitrogen. I'm wondering if I can select for cloned pDEST vectors in these cells using Neomycin or G418. According to the G418 manual, you can theoretically use it for bacterial selection, but I think that may be for libraries and not actually growing up the plasmid.

So is it possible to select for my plasmid in these cells by adding a little G418 to the ampicillin plate? Is this common? I can't find anyone selecting bacteria by Neomycin anywhere.

EDIT - The main reason I ask, is that the resistance gene is under a PGK promoter that I have no idea if it works in bacterial cells.


texts: Common Errors For Low R Value in Bradford Assay

texts: I've recently started doing Bradford Assays for my samples and my standard curve has been non-linear and I have been getting low R values (.90-.95). I initially thought the error was in pipetting, most likely in adding BSA while establishing the standards but I have repeated in care and somehow still get low R values. Are there any other possible sources of error?


texts: In practice, do fishes die from old age?

texts:
I was watching sea birds eating fishes and wondered if fishes actually died from old age, or if they are all eaten before this can happen?

I reckon some big predator fishes must be able to live long enough to die from their age, but fishes who are lower in the food chain, do any of them actually reach an age old enough to die peacefully or are they all somewhat doomed to feed a bird or another fish?


texts:
I understand that the brain itself does not have pain receptors, so when the brain is damaged or cut, there is no experience of pain. For example, surgeons can operate on the brain while a patient is awake without causing pain.

How about the spinal cord? Are there pain receptors in the spinal cord? Will damaging the cord itself cause a feeling of pain?


texts: Why summation takes place at Initial segment?

texts:
I know that many EPSPs summate at initial segment to produce action potential.

But I don't understand why if EPSP can travel from dendrite to initial segment, then why it doesn't travel further?

What halts it there and make it to wait for other EPSPs to come and add to make Action Potential?

Why does it can't propagate as such and cause release of small amounts of neurotransmitters?


texts: Would it be possible/plausible for a type of spider to fly by weaving web between it's legs to create bat-like wings?

texts:
I've been thinking about this lately.  Would it be possible for a type of spider to gain the ability to fly freely by weaving its web between it's legs and creating wings much like those of a bat?

Is there anything like that in nature currently?
Is it plausible at all?


texts:
What I know about centre-surround type receptive fields is that depending on whether the region is on or off, the response to being stimulated is either excitatory or inhibitory respectively. So if a light shines on the centre of an on-centre/off-surround and off-centre/on-surround fields, spikes would be detected in the first case and not the second.

To my understanding, if both centre and surround areas are simultaneously stimulated, no spikes would be detected in either of the above-given fields. However, that means that if I am staring at what is essentially a blank white wall, I shouldn't be able to see anything. But that is obviously not happening. What am I missing here?

Also, on a related note - do on-centre & surround or off-centre & surround fields exist? What function do they serve, if any? What are the other types of visual receptive fields in humans, or other animals? Is there a major difference in properties of visual fields across species?

Edit: While browsing a few resources on receptive fields, I found this very-helpful image here.

This image perfectly illustrates my question: what happens to the grey areas in the right image? How are they processed by the retinal ganglion cells?


texts: Do we see protocells forming in nature today?

texts:
I understand that the current theory of chemical evolution (aka origin-of-life, abiogenesis) involves lipid-based protocells that enclosed RNA and perhaps some other compounds as a first steps to life.

I'm wondering if we see them forming today in nature, and if not, why not?

Are there successful experiments creating them in the lab?  If so, what are the required conditions?


texts: How to interpret different results from Clustal Omega and Multalin?

texts:
I have been working on aptamers, which are nucleotide sequences. They bind to various targets, in my case a particular cell surface receptor. The people associated with the project performed SELEX and they have selected sequences that have affinity for the target. My advisor believes that the sequences could share a particular binding pocket (consensus sequence).

The sequences are mostly 40 nucleotides long but some of them are shorter or longer in length. I have to aligned the sequences in an attempt to identify sequences containing a consensus site. So far I have used both Clustal Omega and Multalin, but the results from them are pretty inconsistent.

Clustal Omega Alignment:

I also aligned a few sequences using a pairwise alignment method, but I found few similar regions among the sequences.

How do I interpret these results from Clustal Omega and Multalin?


texts: Mutation in axillary buds of trees overcoming self-incompatability?

texts:
I seem to recall from either reading or lecture that there have been instances of trees that are self-incompatible accumulating enough mutations in an axillary bud that the resulting branch was able to pollinate flowers on other parts of the tree. Unfortunately, I do not have a source for this information.

Are there recorded instances of this happening, or is this a figment of my fevered brain?


texts:
recently i got into a debate with this question on hinduism.se ,

as the link given above shows, are sperms considered as living or non-living

as far as my knowledge is concerned, sperms undergo locomotion, senescence, more over the best thing to say they are living is they contain genome, i.e. haploid sets of chromosomes

so in short are sperms living or non-living


texts: If all bacteria in human gut are dead, can they be there again?

texts:
If someone likes to eat chocolate, she may have gut bacteria which like chocolate according to some articles that I have read.

http://www.theatlantic.com/health/archive/2014/08/your-gut-bacteria-want-you-to-eat-a-cupcake/378702/

If I do not eat chocolate for a long time, would their number be decreased and other (bad) bacteria dominate the gut?


texts: When I was a child, my father showed me the classic essay "On Being the Right Size", J. B. S. Haldane.  It talks (among other things) about how large animals need stockier legs to support their weight.  I weigh about the same per leg as a 350 lb deer, but my legs are closer in diameter to those of a 1500 lb horse. Why?


texts: What would be the best design for spike-and-recovery and linearity-of-dilution validation experiments in one 96-well ELISA plate?

texts:
I have searched in the web for a detailed explanation of doing such validation experiment, but unfortunately couldn't find a satisfactory one. I came across the following sources:

Thermo Scientific Tech tip #58: IMAHO, well written description, but still there are some issues

Pros

Clear on describing terms and straight forward calculations
Troubleshooting of the results is outlined

Cons

Not designed to be performed in one 96-well plate ELISA
No mention of any acceptable criteria for the both validation tests
No mention of blank

Quansys Biosciences: a practical design to implement

Pros

Both spike-and-recovery and linearity-of-dilution experiments can be performed in one 96-well plate ELISA
Justified introduction of the endogenous sample, which is diluted the same amount as the spiked sample
Addition of blank
Mention of acceptance criteria for both types of experiments

Cons

No mention of troubleshooting
a little bit messy plate design

R&D spike and recovery protocol: a brief one but useful

Pros

Clear on design
Mention of acceptable criteria at least for the spike recovery 80-120%
Mention of blank
Hint about possibility of using diluted neat sample until it gives reading

Cons

One sample was used for assessment and not averaging on 3 samples at least
No mention for any criteria for linearity of dilution

Issues/Questions
    - Q1: How can we combine the two experiments into one plate to spare samples, and materials?
    - Q2: Can we dilute sample with assay diluent instead of sample diluent?
    - Q3: In case low sample material is there, can we skip the neat sample and add 1:2 diluted one instead to spare material?
    - Q4: In preparing spikes in Thermo Scientific tech#58, why was it 10µl spike stock solution added to 50µl sample? what governs this addition, is there any ratio to stick to here or arbitrary ratio? Can we add 90µl sample and 10µl stock solution?

Please feel free to expand sources, or questions, and of course answers are more than welcome to achieve the following aim:

  The best design for both validation tests (i.e., spike-and-recovery and linearity-of-dilution) in one 96-well plate ELISA that will use the minimum amount of sample material as possible with explanation of calculations based on averages and clear troubleshooting plan

PS: I am short of reputation to add important tags to enhance searching, e.g.: ELISA, validation


texts: Why does licking a 9-Volt battery elicits a taste sensation? Can taste be stimulated by electrical stimulation?


texts: What is the typical amount of full length clones in a cDNA library?

texts:
For a Yeast Two Hybrid project we need to make a cDNA library from a single celled organism. We used the Cloneminer II kit from Thermo. We followed the manual and performed all the quality control steps and everything checked out. However out of curiosity we sent 10 individual colonies for sequencing and while all of those give hits in our organism only 40% seem to be even approaching full length in the coding sequence (80-90% coverage).

Is this normal or did we have poor input material/made a mistake? What is the average number of full length clones for a typical cDNA library?


texts: Why is the separation of biochemical synthesis pathways safer and more economical?

texts:
During our first lecture of plant physiology, our teacher told us that the separation of biochemical synthesis pathways was advantageous because it was safer and more economical. The problem I got, while studying this back at home, was that he didn't explain why it is so.

I can understand why it is safer (for example, a lysosome could break down a lot of major components of the cell if that lysosome was not restricted to its area), but it's quite difficult for me to understand why it's more economical, in terms of energy. Any clear/simple explanation about this would be greatly appreciated.


texts: What is a good Microbiology atlas for Bacteriology as online version?

texts:
I am looking for a online atlas for Bacteriology, the cost does not matter.
I have been searching SpringerLink, and Amazon but no good online version found.

What is a good atlas for Bacteriology as a online version?


texts: Are there examples of the green beard effect in humans?

texts:
Green-beard effects are genes that:

Produce an effect that can be detected
Produce preference to others with the same effect

Are there any examples of this in humans?


texts: Do we actually get more sick (flu/cold) during winter?

texts:
The word flu derives from the Italian phrase "influenza de freddo" meaning "influence of the cold".

Indeed it is that time of the year when my colleagues seem to have the flu/cold more often than not. I remember during university, winter lectures would be riddled with people coughing and sneezing - the so called "freshers flu"

Questions

Is there statistical evidence for this claim?
If so, what are the causes/factors involved?
Another post asks why our noses get runnier during cold whether, is this related?


texts: Why does vaccine development take so long?

texts:
The main principle behind a vaccine is to take a deactivated virus, "show" it to the immune system so it can "learn" how it looks like, so if and when the real virus does attack us, our immune system is already prepared for it. Vaccines have been developed using this idea even in the 1880's.
If that's the case, why does it take so much time and effort to develop a vaccine, for example, against covid-19? (and why are there several variants with different measures of reliability?) Is it only about balancing how strongly we damage the original pathogen, too much damage and our body might not learn the correct identifiers, and to little damage and it might still be active enough to cause the disease?


texts: Are mediterranean sharks shyer than ocean sharks?

texts:
I have been diving in the mediterranean for some time and have never seen a shark, heard of anyone seeing one or seen shark diving advertised. And still there are all kinds of sharks in the mediterranean. Why are they so hard to spot?

For comparison: There are a lot of accounts of people seeing sharks in for example the Maldives and other places.

Something like this would be unthinkable in the Mediterranean:
https://www.youtube.com/watch?v=Yg-dUPVzWiM


texts: Effect of cold showers after intense training

texts:
What is the effect of cold showers after very intense training (body fully covered in sweat, high pulse, increased body temperature)?

I'm especially interested in how it affects perspiration.


texts: What do biologists mean when they use the term "biological distance"?

texts:
Here is its usage.

"there is sufﬁcient genetic control to make nonmetric traits useful in anthropological work, and such variables have successfully assigned individuals from distinct geographic regions to their correct groups (for example, ... As such, nonmetric traits are an appropriate means for studying biological distances"

Source:https://www.academia.edu/5201951/Sahara_Barrier_or_corridor_Nonmetric_cranial_traits_and_biological_affinities_of_North_African_Late_Holocene_populations


texts: What are the total number of alleles for a single trait?

texts: Humans receive a copy of gene from both parents and each gene has an alternative form called allele. Does every person possess two genes and four alleles for a single trait?


texts: Explanation of "differential transcript usage" (DTU)

texts:
This paper describes differential transcript usage as

Differential transcript usage (DTU) is a special case of alternative splicing in which a gene’s relative transcript abundance (RTA) profile, the proportion of total gene-level expression that arises from each of the gene’s transcript isoforms, differs between conditions (Soneson et al., 2016). [...] An example of DTU may be illustrated by the scenario where the total gene expression is the same between conditions A and B, but transcript isoform 1 is the predominantly expressed transcript in condition A while transcript isoform 2 is the predominantly expressed transcript in condition B.

My question is: is differential transcript usage essentially the same as the usage levels of particular codons? If not, what is the difference? I am unsure of what "transcript isoforms" are, so I'm not sure whether it's talking about codons here or something entirely different.


texts: Congenital deafness: can cochlear implants always improve hearing at any age?

texts:
People with congenital deafness may acquire a cochlear implant at a later age and be able to hear. Given that it seems there is a curve for synaptic plasticity of different circuits:

(1) Cochlear implants are used in older children (age 3-8) with moderate success. How can we explain the fact that they developed hearing despite not receiving any auditory stimulus in early age?

(2) Can auditory circuits be formed at any age, or is there an age in which the use of a cochlear implants will not be useful anymore?


texts: How to write a palindrome sequence as-wish (create, theoretically) ? (self-answered)

texts:
There are specific examples from nature,  of palindromic sequences.

But without memorizing them, is there any way to randomly write or create or derive a palindromic sequence for a theoretical discussion?

by the way, Genetic palindromes are not an exact ditto of verbal-palindrome.


texts:
Recently an interesting study has reported.  Zhou et al., 2016. J. Cell Biol. http://dx.doi.org/10...3/jcb.201605101

According to this study, enhancing anterograde axon transport of mitochondria is essential for regeneration of injured axons.

Neurons need a large amount of energy provided by ATP to extend their axons when they are injured. Mitochondria transported to axons produces
ATP which is necessary for that.

This study shows that in mature neurons, the motility of mitochondria is reduced and the reduced mitochondrial motility might
be the cause of the deficit in regrowth capacity of mature neurons. Moreover, this study found that enhancing mitochondria transport enables mature neurons to recover their regrowth capacity.

It is said that mature neurons typically arrest their cell cycle and fail to proliferate and regrow. However, considering the fact that
only enhancing mitochondria transport enables mature neuron to recover their regrowth capacity, I can't help but doubt the commonly accepted theory.

Do mature neurons actually not arrest their cell cycle？

What do you think of this finding ？


texts: To what extent is immature eggs in insects (beetles) a good approximation for maximum fecundity?

texts: To what extent is the number of immature eggs from dissected, newly emerged individuals a reasonable approximation for maximum/potential fecundity in insects (more specifically beetles)? I know that many species must feed for the eggs to become mature and viable. However, can a comparison between species on immature eggs still be used to capture the range of maximum fecundity between species or to accurately rank species from low---high fecundity?


texts:
I had a conversation with a family member who is a bio-computer-scientist and he talked to me about what his colleagues (biologist) are doing and I feel confused about it.

They work in Chile and are studying plants that live in the desert.

If I understand correctly his team is trying to explore the idea that some viruses might actually be good for the plants they are infecting and might have been "selected" and are now "part" of the species.

The way I understand it is that they collect samples of plants and somehow by analyzing their DNA notice that these plants are all infected by some kind of virus and they tell themselves that maybe if all the plants have the virus it's because it's good for the plants.

My questions are:

1) Does any of this make sense?

2) If it does how would the selection process happen ? Combining my (old) high-school knowledge and Wikipedia I see a virus as a piece of DNA that goes into a cell and then uses the cell's tools for it's own purpose, but it is not part of DNA. So how can it be treated as part of the plant ?

3) Do you know any good references (preferably for an enthusiast layman) about this subject (i.e. the potential good of some viruses and maybe potential applications in bio-engineering) ? I find especially fascinating the idea that maybe evolution isn't just the result of mutations but also of "contamination".


texts: Can DNA be considered as a fractal antenna?

texts:
I was reading about the consequences of using mobile phones and came across the statement that mobile phones are a potential source of cancers because DNA is a kind of a fractal antenna. The reason put forward for this was that it shares with mobile phone antennae the properties of self-similarity and electric conductivity.

The scientific paper which is the source of this statement appears to be: Blank and Goodman, “DNA is a fractal antenna in electromagnetic fields” Int J. Radiation Biology, 87:4, 409–415, DOI:10.3109/09553002.2011.538130. Is anyone able clarify this assertion and explain whether or not the arguments in the paper support it.


texts:
In this video, a dolphin jumps into a vessel.  Even though the guides know they will be quickly helping the dolphin back into the water, they first make sure they wrap the mammal with wet towels.

Why did they rush so quickly to wrap the dolphin with wet towels?  Is there something about the biology of dolphins that made that action essential?


texts: How long does antibiotic-dosed LB maintain good selection?

texts:
Various people in our lab will prepare a liter or so of LB, add kanamycin to 25-37 mg/L for selection, and store it at 4 °C for minipreps or other small cultures (where dosing straight LB with a 1000X stock is troublesome).  Some think using it after more than a week is dubious, but we routinely use kan plates that are 1-2 months old with no ill effect.

How long can LB with antibiotic such as kanamycin, chloramphenicol, or ampicillin be stored at 4 °C and maintain selection?


texts:
Can humans' ability to dive with only breathing modifications tell us anything about our evolution?

For example, it is possible to imagine a human anatomy that would be destroyed by the pressure of a few meters of water, and yet humans can, with scuba apparatus dive to several hundred meters.


texts: When a brain has a aneurysm and the patient survives untreated then   where does that blood drain to or how is it absorbed? How is the pain perceived?


texts:
Is it possible to ligate a small DNA molecule to mRNA?  I was reading a protocol from Current Protocols in Molecular Biology and one of the procedures involve ligating a DNA molecule to mRNA using a DNA splint that overlaps between the 5' of the DNA molecule and the 3' of the mRNA.

Would a reaction like the following work?

5'-phosphorylated DNA linker
mRNA library
DNA splint
T4 DNA ligase + buffer


texts:
Many fruits are not homologous, originating from different parts of a plant. Yet they all have similar properties:

Ripe fruits all have yellow to dark red color
They all have a lot of water and sugars, even in dry climate where water is in shortage.
Besides sugars they usually have acids making them sour to sweet in taste

I understand that these possibly developed as a contract between the plants and the animals in that the plant would provide beneficial fruit tissue so that the animal to swallow the seed so to propagate it for longer distances.

But I wonder, why there are no fruits that would imitate the taste of meat, nuts, seeds,  foliage, grass, mushrooms, roots, milk and other food sources, common for the animals?

Why there are no salty fruits for instance or those rich in proteins rather than sugar and water, or having the smell of carrion?


texts: Optimal pH of protein buffer? Basic principles to adjust buffers according method and analysis

texts:
Protein buffers such as PBST, which is used in western blotting, are normally adjusted to pH 7.4. When I try to find why, I find some information about optimal pKa for protein stability. Im not sure I really understand this, because it seems as through regardless of protein - most laboratories just use PBST with a pH of 7.4.

I am a bit curious about this, and have a few questions

Why is pH 7.4 set as the standard for western blotting?
For an optimal western blots, should the pH always be above the pI of the protein?(since 7.4 seems a bit high)
Should the pH of a buffer be at the pI of a protein for extractions before SDS-pAGE, and while washing NC-membranes after blotting?
How should one calculate the optimal pH, or evaluate/think about this when working with a protein?


texts: Meaning of acceptor/donor splicing sites?

texts:
What is the meaning of acceptor and donor in acceptor site and donor site expressions in the context of RNA splicing. Note that I know the biological meaning of these concepts. I am just intrigued by the terms acceptor and donor.

I just cannot seem to find the reason why one is called acceptor and other donor. What exactly is being accepted and donated? In addition, it would be nice to have a reference to the original work that used this terminology.


texts: Why would an Eadie-Hofstee Plot be non-linear?

texts: Besides cooperativity between multiple active sites on an enzyme, what are the other reasons for the Eadie-Hofstee plot to be non-linear?


texts: Why mosquitoes sit on wall vertically (head upper side)?

texts:
I was curious to know why mosquito sit on walls or trees vertically like head towards sky, unlike other insects like fly, ants, termites sit with any direction.

Also, what they do sitting doing nothing (rest/digestion may be)?


texts: What could cause sudden deafness and deliriousness on a boat adrift?

texts:
I'm reading a completely nonfiction book  called In the Heart of the Sea, and in it, the characters are lost at sea without food and they are starving. They cast lots to see which crew member will be eaten, and it lands on one of them. He asks for the night to resign himself to his fate, and the other members accept. However, by midnight, he'd become deaf and by morning he was delirious. Why would this happen? It wasn't starvation-induced because they'd used up the very last of their rations that night in a large meal. So why did the threat of death induce deafness and deliriousness?

Edit: And it was 100% true: not only was the book nonfiction, there are accounts from the surviving crew members of the event.


texts: How can I interface cAMP signal or membrane potential from slime mold to an electrode?

texts: I am very much interested in measuring cAMP (cyclic adenosine mono phosphate) signal and membrane potential from amoeba. Since I want to try this as a hobby, what are the basic steps I must do to view these signals on a CRO (cathode ray oscilloscope). Cyclic-AMP being a biochemical, how can I view it as a corresponding electric signal?


texts:
I was recently browsing the web and came across this site abut the compact dodder.

https://gobotany.nativeplanttrust.org/species/cuscuta/compacta/
The image used to identify the plant shows it as purple. This struck me as odd, as those are usually a greenish-yellow. Why is this plant purple? Is it a special sub species? Is it perhaps another type of dodder entirely, and gobotany simply messed up? I think this image might actually show the Cuscuta glomerata, but I'm not sure. Please explain this discoloration. Thanks in advance!


texts:
I came across this plant yesterday (14th May) and was wondering what it might be? Would anybody know the scientific name and if it's indigenous to the UK (personally I doubt it is)? The plant grows in an Asian style garden near Cumnock, Scotland.

Close up of leaves:


texts: Meaning of "standard reactions" in a DNA extraction procedure description

texts:
From a DNA extraction procedure description (an in-house pharma document I'm translating into Russian):

Preparation of Standards

All the standard reactions should be prepared at least in duplicates. The template DNA stock (CHO cell genomic DNA) should not be less than 100 ng/μL concentration.

Does "standard reactions" here mean what it says, or does it really mean "reactions with standards" (reactions using standard samples)?
P.S. It is part of a qPCR procedure to quantify host cell DNA content. The company is producing a monoclonal antibody drug and is describing its internal procedures. As a translator I cannot disclose the document in full.


texts: What is the mechanism behind sympathic effusion of serous cavities due to nearby abscess?

texts: Patient with left perinephric abcess which does not ruptured have reduced breath sound that is mostly due to plural effusion revealed by CT scan which was sterile. I found this called sympathetic effusion , Why it named as this and what is the mechanism behind it ?


texts:
Note : Any answer to this question will not be (and should not be) taken as medical advice.

One of my friends has allergic rhinitis and has been prescribed an oral vaccine. He is allergic to 3 different classes of substances and so, has been given 3 different types of vaccines. He has to place them below his tongue.

I am curious about some of the procedures he has to follow.

1.How does a vaccine of this type work ?

2 He has been given 2 vials for each type of vaccine. First one is labeled SRS and other one as I understand is - it's allergen. So, What is SRS ? What's the requirement of it ?

3 It is written in the instructions that he should not eat anything one hour before and one hour after taking the vaccine. Why ?


texts: "Air sac" and "air cell" in a chicken embryo

texts:
I need to translate the Russian term "воздушный мешок". It is part of the chicken embryo, marked by number 5 in the figure below.

I found the expression air cell but also found the expression air sac in English. On one site, "air sac" is described as a synonym to the "allantoic sac":

Just to make sure: is air cell the only correct translation for the structure marked by number 5?

My sentence goes roughly like this:

  ...  the injections are made from the direction of the naturally-occuring air cell (?) so as to apply the material onto the chorioallantoic membrane (CAM).


texts: I am Just confused whether solitary means single flower in the whole plant or one flower on one branch of the plant?


texts: Why is there an increased risk of embolism in any malignancy? I studied that malignancy is a risk factor for pulmonary embolism. Can someone explain me the exact mechanism under which malignancy produces emboli?


texts: What is the mechanism that directs myosin walking?

texts:
Myosin, dynein and kinase all "walk" towards specific ends of the microtubule or actin filament they are on. I'm most familiar with the walking mechanism for myosin, where ATP fuels conformal changes in the binding region, but I don't understand how it chooses to go one direction over another. Actin fibers' positive and negative ends are fueled by the addition of G-actin via ATP and its subsequent reduction to ADP, so I suspect that this process is somehow involved in determining the direction of myosin's movement.

As just a secondary thought, are there differences in the mechanisms of the movement between the three walking molecules listed above?


texts: Linkage between chromosomal loci and the Hardy-Weinberg principle

texts: Referring to the Hardy-Weinberg principle, which is always stated with respect to a particular locus on the chromosome, if we observe that two different loci are either always together in Hardy-Weinberg equilibrium, or never together in Hardy-Weinberg equilibrium, can this give us any information about the linkage between the two loci?


texts: How to calculate relatedness in haplodiploid organisms (mainly full sisters and full brothers)?

texts:
I have tried to calculate the relatedness for haplodiploid organisms, but cannot understand the calculations behind full sister and full brother.

(taken from Wikipedia: haplodiploidy
I have managed to solve the other cases. Since female will have ZZ:

female will share 1/2 of her genes with daughter
female will share 1/2 of her genes with son
female will share 1/2 of her genes with mother
female will share 1/2 of her genes with father

Since male will have only Z:

male will share 1 (100%) of his genes with his daughter
male won't share anything with his son (unfertilized eggs leads to male in haplodiploidy system)
male will share 1(100%) of his genes with his mother
male won't share anything with his father (unfertilized eggs leads to male in haplodiploidy system)

Even though I figured out how others work, I wasn't able to calculate r for fullsister fullbrother? How can it be 3/4,1/4,1/2,1/2?


texts: how much grass does a sheep eat in square meters per day?

texts:
I want to buy some sheeps in order to eat my garden's grass.

How much grass does a sheep eat each day ??


texts: Can prawns and lobsters live out of water for more than six hours?

texts:
I live in Telangana which is a state of India.I like eating Non-vegetarian food.People of our state eat pond fish more comparing to other aquafood.In many places near me,I've seen people cutting alive fishes in to pieces with their big knives.I won't feel good to see this.So,usually I bring the pond fishes home and keep them aside for atleast 40 minutes with no water in contact to them.In these 40 minutes I prepare other ingredients needed for the recipe.After these 40 minutes,generally as there is no response from those fishes I start cutting them into pieces.In the same way I don't know how much time it will take for prawns and lobsters to die without water.Do they live more than six hours without water?

This question is not related to the experiments carried out by the biologists on lab creatures.They are great people.I encourage their experiments whether it involves humane killing or inhumane killing because their experiments on one creature may help millions of remaining creatures.


texts: Are there animal species with sex of an offspring determined by sex of preceding offspring?

texts:
For instance, if an animal's first offspring is male, then all subsequent offsprings will be male too (the sex of first offspring could be determined randomly).
Does it happen in any species?


texts: Can the regeneration mechanism of lizards be used in humans?

texts: Is there any mechanism or specific protein which helps lizards to regrow their tail? Can the mechanism of regeneration be used in humans to regenerate our limbs? Is there any other animal which has this kind of ability?


texts: How can Giant squid have $20,000 mm^{-2}$ photoreceptor cells, but no cones?

texts: According to this post, Cephalopods have about $20,000 mm^{-2}$ photoreceptors in there eyes. However, Cephalopods (in my case, the Giant Squid) aren't born with cones (cells that dictate which colours you see). So are they born with about 20,000 rods (cells that help detect movement), or is there another type of cell involved?


texts: ChIP-seq for histone modification not in agreement with RNA-seq for expression

texts:
I have ChIP-seq for H3K79me2 and H3K36me3 and RNA-seq data for treated and untreated samples. Those two histones mark active genes. Lets say, hypothetically, a peak caller finds differential sites at gene A for both of those histone modifications. However, when I run RNA-seq analysis tools (like edgeR or DESeq2) this gene is not marked as differentially expressed (well it has a FDR value of >0.05).

There might be several technical reasons for RNA-seq analysis methods not to find this gene as differentially expressed because

it is really not differentially expressed
or it is not differentially expressed enough for the tools to detect it

However, I am more interested in the biological aspect. If two histones mark gene A as active in treated samples, one would expect that it would be expressed in RNA-seq. What mechanism could lead to the result that however the genes is marked as active by histones, it will not be differentially expressed in RNA-seq?


texts:
I heard that loss of blood kills shot animals, a lot. But a few times, I heard that mechanical shock kills animals. For example in this video (starts to play at the right spot; relevant from 14:35 to 15:03).

That loss of blood kills an animal seems pretty obvious as the brain can't function without being supplied oxygen and it can't be supplied oxygen if there is no blood to carry the oxygen.

If the mechanical shock is applied to the head, it also seems somewhat reasonable. I guess it could be that the shock destroys vessels in the brain. But other than for a headshot: Is there a biological reason why an animal couldn't continue to live after experiencing mechanical shock due to being hit by a small projectile (being hit by a truck which is able to accelerate the entire animal doesn't count)?


texts: What physiological processes give rise to a linear cell survival curve?

texts:
If we plot the number of surviving cells in a structure over time (assuming no replacement), the shape of that curve should imply something about the underlying process responsible for cell death. For example, if surrounding conditions mean that each cell has a constant probability of dying within a given interval, then an exponential decay curve should be seen. If the cell has a characteristic lifetime (with say a gaussian distribution about that mean lifetime), then (I guess) we might expect something like a logistic S-shaped curve.

In Parkinson's disease, the onset of motor symptoms is related to the number of dopaminergic neurons in the substantia nigra pars compacta, a small structure of just several hundred thousand neurons. The decline in cell numbers due to the disease process is indeed usually modelled as something like an exponential decay.

But there is also a normal age-related decline in substantia nigra neuron numbers. This decline is usually modelled as a linear decrease from birth through to old age, at something like 0.5% to 1% per year (Rudow et. al., 2008. Morphometry of the human substantia nigra in ageing and Parkinson’s disease. Acta Neuropathologica, 115(4), 461-470 http://dacemirror.sci-hub.tw/journal-article/fc4e7854ee0cef0146d60756536b2a88/rudow2008.pdf )

Note that this percentage decline per year is not a percentage of the surviving number (which would yield an exponential curve), but of the original total. In effect, it is perhaps best to think of it as a decline by a constant absolute number of neurons per year, yielding a straight line survival curve.

Exponential decline is memoryless (conditions simply conspire such that the probability of any cell's death is constant in a given interval, uninfluenced by the history of that cell or any other). The death of a cell with a characteristic lifespan, meanwhile, does have memory, as the probability of a given cell dying increases as that cell ages and deteriorates. But the death of a constant number of cells in a given interval somehow implies a sort of memory across cells, such that the number dying in a given interval is related to the initial number, and not to the current surviving population level.

My question is what general physiological processes are consistent with such a linear decline? i.e. is a linear decline a common pattern for neurons or any other sort of cell death, and in general, what sort of process governs it?


texts:
Is there a list of neural coordinates for C.elegans? I need it to build a 3D model.

Update:
What is available at the moment is:

full connectome for example, at openconnectome;
neuron description with images of relative position at wormatlas;
2d position data at dynamic-connectome.

Update 2:

I've created very simple 3d model that consists of three layers (left, right and center) based on neuron labels. This shouldn't be considered as a real biological, but better than nothing. Code and data is on github.

Clarification:

The question is still there, I've provided very basic model and everyone are welcome to use it. But it still would be interesting to get experimental results. I'll keep the question open in case someone could share the data.


texts: Is it possible for parsimony to estimate more state changes than stochastic character mapping

texts:
I'm mapping states (geographic regions) onto a phylogeny to estimate the number of transmissions between countries.

I'm using two methods, stochastic character mapping implemented in Phytools and parsimony implemented in Mesquite.

I was expecting parsimony to give lower results than stochastic character mapping, as it doesn't attempt any simulation along branches. This is generally true, and the number of transitions between states is generally lower estimated by parsimony. However, in a couple of cases, the number of transitions estimated by parsimony is higher than by stochastic character mapping.

I'm still developing an intuition in this type of analysis, so could someone tell me if this is feasible, or should I be looking for a technical problem somewhere?


texts:
I often find these, what I assume to be shells, during walks along the beach. I haven’t seen any creature or plant alive that has this feature and research attempts haven’t been successful.
There are bright reflective blue streaks along the shell and it is yellow-brown coloured and transparent. I have found these along the Northern Irish coast


texts: Is natural selection a tautology, and therefore not truly falsifiable?

texts:
I've heard the argument from a lot of creationists that all the evidence for natural selection (and by extension, evolution) in general is worthless because natural selection is so flexible that it could cover all the data, no matter what we discovered. In essence, that natural selection is a tautology:

Survival of the fittest. What is 'fit'? What survives.

There are other creationists, however, that admit that natural selection could be falsified. These are split into two groups:

The ones that say, if you rephrase natural selection as a non-tautology, it becomes obvious that it doesn't work:

  Natural selection has been criticized as a tautology. This would be a major problem for evolutionary biology, if true, because tautological statements can't be falsified and, therefore, can't be scientific. There is merit to this critique insofar as the theory of natural selection is indeed generally described in a tautological manner. However, natural selection can be described non-tautologically if we’re careful. Natural selection should be defined as the theory that attempts to predict and retrodict evolutionary change through environmental forces acting upon organisms. However, this re-framing comes at a cost: it reveals, based on our current knowledge of evolutionary forces, the lack of ability to make accurate predictions about expected changes except in the most simple of circumstances.

And those that say that the falsifying options provided by natural science are impossible to actually use. Here are some of those falsifying options:

  Charles Darwin himself proposed a rather strong test of evolution: "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down." [Darwin1859, pg. 175]. This is the basis of claims by various intelligent design writers that various biological structures, such as the vertebrate immune system or the bacterial flagellum, are "irreducibly complex" -- they consist of multiple components that could not develop in the absence of the others. However, these structures have been exhaustively studied in the scientific literature, and scientists have demonstrated entirely plausible evolutionary pathways. See Complexity.
  Famed biologist J. B. S. Haldane, when asked what evidence could disprove evolution, mentioned "fossil rabbits in the Precambrian era" [Ridley2004, pg. 66]. This is because mammals, according to current scientific analysis, did not emerge until approximately 40 million years ago, whereas the Precambrian era is prior to approximately 570 million years, when only the most primitive organisms existed on earth.
  Biologists had long conjectured that human chromosome number two was the result of a fusion of two corresponding chromosomes in most other primates. If DNA analysis of these chromosomes had shown that this was not the case, then modern evolutionary theory would indeed be drawn into question. This "fusion hypothesis" was indeed confirmed, rather dramatically, in 1993 (and further in 2005), by the identification of the exact point of fusion. For additional details see DNA.
  Modern DNA sequencing technology has provided a rigorous test of evolution, far beyond the wildest dreams of Charles Darwin. In particular, comparison of DNA sequences between organisms can be used as a measure of relatedness, and can further be used to actually construct the most likely "family tree" hierarchical relationship between a set of organisms. Such analyses have been done, and the results so far dramatically confirm the family tree that had been earlier constructed solely based on comparisons of body structure and biochemistry. For additional details see DNA.

Is there any way to save natural selection? To do so, we need to:

Prove it can be explained non-tautologically
Prove that it does make useful predictions
Give falsifying experiments that are reproducable and actually possible.


texts: How can I detect which antibody is produced by the B cell?

texts:
In the primary immune response, IgM is produced (in addition to IgD ). In the secondary immune response, various types of antibodies are produced.
So how do I detect which antibody a B cell is producing at a particlular time?


texts:
Walking  by the lake and watching the ducks the other day a thought struck me; there are lots of aquatic birds but all remain at least somewhat terrestrial, nesting on land.

Why is it that no birds have taken the evolutionary route of the dolphins and whales and returned to the sea?

Is there something in avian biology that means this is not possible?


texts: Is there a minimum amount a muscle can move? And thus, gaps in our movement?

texts:
Lately I've been thinking about something, based on my knowledge my chain of reasoning works like this...

When you want to move a muscle your brain sends an electrical nervous impulse along the chain of nerve cells to the muscle you want to move.

A nervous impulse is nothing other then a jolt of electricity, the voltage is uniform and the only difference is the rate the jolts are sent, resulting in faster movement.

When a muscle is hit by electricity it's reaction is to contract, this is what creates movement.

Given all this, is our movement continuous or quantized? Let's say one jolt moves my finger 1 degree, another jolt would move it another degree. Would that not make it impossible to move my finger 1.5 degrees? To me it stands to reason that while you could shut off the power to your finger at any time, making it theoretically continuous, there must be a minimum amount of frequency by the impulses needed to cause any movement.

If this is true then the movement of our bodies is the microscopic snapping through possible positions. And therefore there must be a finite number of possible positions our bodies can take. Like a knob that can only click it's way through the pre-determined positions on the dial.

Is all this true? Do nervous impulses work like I think they do? Are there things about nervous impulses or muscles we don't know? Are we capable of only positioning ourselves in this quantized way? Has anyone proven any of the things I have said? Please consider you answer carefully.

Personally I hope our ability to position ourselves is continuous.


texts: What's the cause of the scars on these cherries?

texts:
These cherries have some scars. Are they coming from a disease? Is it correct to call them "Cherry scabs"?

Here's the photo:  -


texts: How does Ran GDP get from the cytoplasm back to the nucleus following nuclear import and export?

texts: I understand that in Ran-dependent nuclear import Ran GTP binds importin in the nucleus, and after diffusing through the nuclear pore complex Ran GTP is hydrolyzed to Ran GDP and releases importin. How does the hydrolyzed Ran GDP get from the cytoplasm back through the nuclear pore complex to the nucleus? The same question applies to nuclear export after Ran GTP is hydrolyzed following export of the Ran GTP-exportin-cargo complex. Does Ran GTP freely diffuse through the nuclear pore complex? Is it actively transported?


texts: How is evolution possible in contemporary humans?

texts:
I would like to know if evolution is continuing to happen in modern humans, assuming things like existence of the nuclear family structure, fidelity to one partner, etc. It seems to me the answer would be NO because evolution depends on differential reproductive rates, but in the modern world, all male humans have roughly 2.5 (or whatever the number) kids. Add in the process of culturally modified selection pressure, and it seems to me that even an "unfit" male would end up having a couple of offspring. The fittest male (or female) is no better off than his or her contemporaries because of this "leveling" effect.

However, the impression I get from the popular science media is that scientists think evolution is continuing to happen. I would like to know what the actual scientific consensus is, and why. Thanks.


texts: Identifying a spider from coastal Virginia

texts:
A spider recently put up a web in my room in coastal Virginia, USA (on the left in the photo).

Rounder/taller body than most species I've seen. Dark brown, not quite solid-color coloration. If laying flat, it looks like its body would be about the size of an American dime. Tends to hang with its underbelly pointed upwards, and the times I've watched it feed it has never attempted to wrap prey in silk –- instead, it immediately eats and discards them.

My best guess from what I was able to find online was Araneus diadematus, but the coloration on all the examples of that species I can find seems much more varied than what I'm seeing, and I'm not particularly well-versed in spider identification, so I'm not sure.

The spider on the right was new this morning, I'm less curious about it and presume it was just a male of the same species.


texts:
The evolution of eucaryotic cells is usually described as an event wherein one procaryote engulfed another probably smaller procaryote and rather than the engulfed procaryote being taken apart the two cells formed a symbiotic relationship each benefiting from unique elements of the other while retaining their unique individual DNA.
Seeing as the first eucaryotic cells replicated themselves through cell division, how was the synchronization of division of the two original cells achieved?
Perhaps I should make it clear that I am not enrolled in any university but am a lifelong student with an interest in evolution and genetics.
Thank you for your time.


texts: How important is dead wood to the ecology of a forest and how much dead wood should remain?

texts:
I have a local 'forest management group' in my area. One of the jobs they do is to thin out the forest by removing some of the trees. They then sell the wood for firewood.

I want to tell them to leave the dead wood in the forest, as it is part of the food chain.

Can anyone give me an estimate of how much energy dead wood provides for the food chain in a temperate forest, as a percentage of the overall energy generated by the forest?

Also how biodiverse is a forest with the dead wood left alone compared to one with the dead wood removed?


texts: Do lysogenic viruses only infect bacteria?

texts:
In the video sent by my teacher on viruses, the example he used for lysogenic viruses was a bacteriophage infecting a bacteria. When he was describing how the genetic material was incorporated into the host cell's genetic material, he said something along the lines of:

  Now the genetic material is incorporated into the cell's chromosome.

My question is, did he describe it as one main chromosome because that was the example being used? Or do lysogenic viruses only infect bacteria?

I guess a better way of phrasing this would be, are bacteriophages the only type of lysogenic viruses?

Thanks!

evamvid


texts: Is it possible to determine if it is the 5’-a 3’ strand or the 3’-5’ strand?

texts: DNA is constructed in an antiparallel manner.  This means if you number each of the 5 carbons in the sugar deoxyribose the 3rd carbon will be connected to one phosphate group and the 5th carbon will be attached to another phosphate group of another nucleotide.  One strand will go from the 5th carbon atom to the 3rd carbon atom in one direction(5’ -3’).  and the complementary strand will go in the direction of the 3rd carbon to the 5th carbon in the same direction(3’-5’). Essentially they are made in opposite directions.  If I tell you the nucleotide base sequence of one strand is ACGGACTA.


texts: Do IgM and IgG differ for different infections?

texts:
I am not that much educated in the medicine and immunology fields. So I noticed that there are tests for IgM and IgG immunoglobulins for various infections. I was not able to google quickly if IgM for one type of infection differs from the one for another type of infection.

I guess they differ because otherwise there would be only a few tests in the laboratory instead of dozens. But it would be great to hear some solid explanation.


texts: Why do my peptide samples turn yellow and red?

texts:
The protocols for (brain) tissue digestion I am trying out are: lysis (buffer containing 0.1% SDC or SDS in 100mM TEAB + phosphatase inhibitor which is sort of yellow), reduction with TCEP, alkylation with iodoacetamide, digestion with trypsin, and acidification with trifluoroacetic acid (TFA) to deactivate trypsin. After that I usually dry the sample and do a C18 clean-up.

For some reason my samples become yellow after the addition  of TFA (and this was also the case with lysis buffers with SDS or SDC so I don't think it is detergent related). As this happened to a colleague who didn't use the phosphatase inhibitor, I don't think it's related to it either. When I do the C18 clean-up this yellow goes to the eluate (elutes with peptides). Would anyone know why this yellow colour occurs? The most disturbing thing for me is that it does not always happen to every sample, as you can see in the photo 0.1%SDC is clear.

Moreover, for the last digestion, I decided to try out Rapigest (0.1% in 50mM TEAB). When I added the TFA for acidification step, the sample was still clear, but after a while drying it in SpeedVac, when I checked up on it, it had a bloody red pellet-like oddity as you can see in the photo. I left it in the SpeedVac to dry out completely, and when I checked it again, the red colour disappeared and it was clear-whitish again. Would anyone know why this happens and if it interferes with subsequent steps such as C18 clean-up or LC-MS identification? So far, I have asked my colleagues, but they have never seen it before and are calling it magic.


texts: Is ivy (genus Hedera) a shrub or an herb?

texts:
It seems like the difference between a bush (shurb) and an herb is that a bush has a woody stem.

What does that make ivy (genus Hedera)? I know that ivy can get a pretty hard stem, does that count as woody? Is there something between a bush and an herb?


texts:
I read on the web that the size of Y chromosomes decreased in earlier period of time and the picture below tells that it is still occurring.
So basically I want to know what caused  this shrinking and if it has stopped now then what caused this break ??


texts: What is the function of E-coli bacteria in our gut?

texts: So, I recently came up with this question. I  googled it, but couldn't understand the proper functions of E-coli bacteria. A little definition would be wonderful.


texts: What is the difference between clinical and non-clinical depression, and is there a term for different severity of the bipolar disorder?

texts:
I was looking for a term which describes a bipolar disorder of lesser severity.

I know from experience from someone I know well, what a very severe case of the bipolar disorder looks like, when an otherwise very intelligent and very sane person can become completely unstable in both directions, and requires medication to basically survive it.
I'm searching for a term which has indeed the symptoms of the bipolar disorder, but is not as severe as to require medication to basically survive the mood swings. I'm not talking about being just sad for something or craving attention. I'm talking about the very real symptoms of mania, followed by depression, just not as severe to be fatally dangerous without medical intervention. A severity which I would describe of being able to cope with by learning about it and a good degree of self-control, exercise, and good eating habits.

I thought the term was clinical versus non-clinical depression, but a search of the Internet made me doubt it. They talked about it as if the clinical was a case where there is a "disorder of the brain" and the non-clinical was "just sad because of a sad event", so either were those forums wrong (I guess so, because of their apparent unprofessional writing style, and they never seemed to know about bipolar, they thought manic depression was just about being very very sad), or there is another term which best answers my question.


texts: "The rhesus macaque is pretty much the closest thing we have to humans" -- why?

texts:
Vincent Munster (researcher at Oxford) states (in the context of testing vaccines for COVID-19):

  The rhesus macaque is pretty much the closest thing we have to humans

I thought chimpanzees and bonobos were the two living species most closely related to humans? Why don't we try the vaccines on them instead? Why is the rhesus macaque a better candidate?


texts: Sometimes when a person gets touched on one part of the body they feel it else where and may think it came from a different part of the body. What causes this? Other examples are similar to why you can trick your self into thinking your arms are heavier than they really are. another would be that you can close your eyes and move in circles up and down your arm slowly and then when you guess where u are touching your hand is higher or lower than expected. What causes these things?


texts:
How do we differenciate between catabolic and anabolic reactions?

According to my researches;

Catabolic Reactions

  Catabolic reactions (also called “catabolism”) break down larger, more complex molecules into smaller molecules and release energy in the process. The smaller end products of a catabolic reaction may be released as waste or they may be fed into other reactions. The energy that is released by catabolic reactions can be captured and used in many ways. Some of the energy is released as heat and increases the temperature of the cell. Sometimes the energy is stored in the chemical bonds of another molecule. And sometimes it can be used to do work, such as movement of cellular machinery to power the active transport of materials across cell membranes. Catabolic reactions are central to biological processes such as cellular respiration and the digestion of food molecules.

Anabolic Reactions

  Anabolic reactions (also referred to as "anabolism") use energy to build more complex molecules from relatively simple raw materials. “Anabolic” and “catabolic” sound similar but are opposites. To remember the difference, it may help to think about how “anabolic steroids” promote the buildup of muscle mass. All of the complex molecules of life — carbohydrates, lipids, proteins, nucleic acids — are generated by anabolic reactions. Anabolic reactions are central to processes like photosynthesis, protein synthesis, and DNA replication.

Here are my questions

Is there water in every chemical reaction?
Do i just need to look at water ($H_{2}O$)?

Regards


texts: Can immune cells be recruited to an area of inflammation, and later go on to a second?

texts: With regards to innate or adaptive immune cells... can naive/immature cells such as neutrophils, monocytes, macrophage/dendritic cells or adaptive T-cells be recruited to an area of inflammation, for instance an infection in the gastric mucosa, then leave that area and be recruited to another different area of inflammation? Or once recruited to a site are they unresponsive to other events?


texts: Assessing beta diversity variations with time

texts:
I'm just starting in the field of ecological statistical analysis and I have a few doubts regarding a dataset that I'm working on.
The dataset is composed of several samples collected at a single location during a few months multiple times per day.
From my data I have estimated the beta diversity (Bray-Curtis dissimilarity) and I'd like to know if there is a monotonic trend with time and how much of the diversity can be explained by the different sampling hours or days.
My questions are the following:
- Is the estimation of Mantel's Rho using Spearman correlation is a valid estimator for the linear temporal trend?
- To estimate the source of the diversity (days/hours) would it make sense to run a npmanova analysis (as I'm using R I'd run adonis in particular) using as explanatory variables the sampling hours and dates?


texts: Most root hairs are unicellular but why is it so? What advantages does a plant derive from a unicellular root hair that it couldn't have if it was multicellular?


texts:
If I wanted to make $500\mathrm{\mu g}/\mathrm{ml}$ of invertase, from Sigma's Invertase from Baker's yeast, which states is grade VII, and greater than or equal to $300 \mathrm{units}/\mathrm{ml}$, then would these following calculations be right if I wanted $10 \mathrm{ml}$ of $500 \mathrm{mg}/\mathrm{ml}$ concentration of enzyme solution?

\begin{align}
M_1\times V_1 & = M_2\times V_2 \\
(300 \mathrm{units} ??)\times V_1 & = 10 \mathrm{ml}\times(500 \mathrm{units} ??) \\
V_1 & = 16.6 \mathrm{ml}
\end{align}

Therefore I need $300 \mathrm{\mu g}$ of the powdered enzyme which is equal to $0.0003 \mathrm{g}$ and add up to $16.6 \mathrm{ml}$ of sodium acetate buffer, to get my desired concentration of $500 \mathrm{\mu g}/\mathrm{ml}$?

Aside: And also, would this solution be able to be made in a day in advance and stored cold or would the enzymes degrade too much?

EDIT:

After reading the comments, googling, and looking back at old protocols. Is the following calculation below right then?

I need $500\mathrm{\mu g}/\mathrm{ml}$ as my concentration, therefore if I want $10\mathrm{ml}$ of my solution:

$$
(500 \mathrm{\mu g}/1 \mathrm{ml})\times 10 \mathrm{ml} = 0.005 \mathrm{g}
$$

Therefore, $0.005 \mathrm{g}$ up to $10 \mathrm{ml}$ of buffer.


texts: Can two humans with 44 chromosomes produce viable offspring?

texts:
It is known that there are very few individuals having 44 chromosomes, not the usual 46 chromosomes.

One example is a male in China: the first article, the second article.

The other is a female in Turkey, unfortunately the article is in Turkish.

It is claimed in the links that they might reproduce and make healthy children if they mate. So I wonder if this already happened and such a couple is living, or if it would be theoretically possible?

Edit: As requested, here is the Karyotype of Turkish female, which the professor in the video call her HomoNeoSapiens, with Robertsonian translocation between 13 and 14 chromosomes. So, this translocation is different from Chinese Man's translocation, which is between 14 and 15 chromosomes. So in this case they can't breed a healthy children? Gosh, I was about to create a new species :((


texts: What is the total mass of leaves on an 'average' mid-latitude deciduous tree?

texts: I know that this is a broad question as there are a very large number of different species of tree with all manner of profiles, height, leaf sizes, etc. My ultimate goal is to estimate the total mass of leaves that fall each autumn in both the Northern and Southern Hemispheres, separately. It seems appropriate to ask for a single tree to start with, hence this question. If there is a better way to get to the final 'ultimate' answer, feel free to post it.


texts: Found this spider on the flower bud in my garden. It measures about 5mm. I am from Kuching, Sarawak, Malaysia.