2
votes
1answer
250 views

What is this insect?

These photographs were taken today in Marseille, in the Mediterranean coast of France. My French friends inform me that these beasties are called cousins because they are "cousins" of mosquitoes ...
1
vote
0answers
40 views

What parts of the brain are involved in regulating blood pressure in mammals?

I'm reading this Wikipedia article on blood pressure and its regulation, and it mentions that medulla is involved. however, I vaguely remember reading another article on Wikipedia and it mentioned ...
-2
votes
1answer
377 views

Are we evolving to age slower, or to live longer aging at the same rate?

I wonder why most of us find senior people lovely and charming. Is it because to love grandpa and granny is vital to our survival as a species, in the same way as we love babies? If so, it would mean ...
8
votes
1answer
1k views

How does this illusion work?

I found this image on Google+ If you shake your head you can see a portrait of a person. Can anyone explain how the image is constructed in the brain?
2
votes
1answer
77 views

Identify this waterfowl species?

I've been unable to find anything on the Google resembling this bird. I took the photo in Virginia Beach, VA around 2010, October, I think... It appears to be between winter and summer plumage but I'm ...
0
votes
1answer
58 views

Why is epinephrine not part of the somatic nervous system?

I learned that the adrenal medulla releases epinephrine, which is a vasodilator of the vessels that lead to the skeletal muscle. I also learned that somatic nervous system only uses Achetycholine as ...
6
votes
2answers
141 views

Can any species be bred selectively/engineered to become as diverse looking as dogs?

I've done some research and it appears that dogs are the most diverse looking single species of mammals. The questions that interest me is - are dogs special in respect to genes/gene activation ...
2
votes
1answer
116 views

Does precipitation influence the UV spec reading?

I have been checking my sample for Hydroxyl radical scavenging activity. I have dissolved Hydrogen peroxide in Phosphate buffer. My sample is clear and reagent is also clear but when I have mixed my ...
1
vote
1answer
48 views

Introductory text for primatology

I'm looking for a book that provides a good overview of primatology, one aimed more at researchers rather than a popular science book. Ideally, I'd like something with an ethology/ecology angle with ...
2
votes
1answer
76 views

Do cockroaches eat their shells after moulting?

I recently witnessed a cockroach eat its shell after it moulted. Do cockroaches always do this?
3
votes
1answer
99 views

Would non-human carnivores be able to survive on farmed foods?

Certain creatures that are considered carnivores are non-obligate carnivores and are technically omnivores (such as wolves/dogs). How different is the potential digestive ability of these species ...
2
votes
1answer
535 views

Optogenetics - How do microbial opsins work?

I'm just introduced to the optogenetics method and am having some trouble grasping the genetics (of the optogenteics) part of things. So we have Retinal and Opsin that form Rhodopsin molecule that ...
0
votes
1answer
51 views

What is a good review article source for Physiology?

I am looking review articles for Physiology. For instance, Physiological explanation of steps of measurement of the metabolism by Douglas-Haldane. There is no section for Physiology or metabolism in ...
1
vote
0answers
54 views

Removing bacterial contaminants from resin

We have a few Strep-tactin columns that had some growth in them and we would like to regenerate the columns back since the resin is quite expensive. Basic goal: remove the brown stuff. So far, I've ...
2
votes
1answer
231 views

How do fully dioecious plants determine sex?

I know that a minority of plants are fully dioecious, with adult plants producing either only male or only female flowers. When is this sexual differentiation determined? Is the seed of such a plant ...
6
votes
2answers
207 views

How do infectious bacteria know when their numbers are high enough to attack a host?

When you get sick, you generally don't contract enough bacteria at once for them to succeed in battling your immune system, right? Their numbers must gradually increase in the host's body before they ...
5
votes
1answer
187 views

Is there a practical upper limit to amount of nucleotides or genes in a transformed plasmid?

I'm currently working on a synthetic biology project which involves working with lots of different parts. I would ultimately like to integrate these genes by transforming a single plasmid. I've heard ...
9
votes
2answers
394 views

Does arterial blood always flow away from the heart?

Is there a negative net flow of blood in human arteries at any point of the cardiac cycle? I realise that blood flow can be turbulent, e.g. in the aorta or around stenotic arteries, but then the ...
3
votes
1answer
387 views

Meat and mushroom allergies, why are they so rare?

There are a lot of food allergies, but for some reason not to meat (mammalian meat or poultry) or mushrooms. I've googled a bit, and now I know that one can actually have a meat or mushroom allergy, ...
2
votes
1answer
111 views

Why is elevated homocysteine considered a risk factor for angina?

Elevated homocysteine levels are listed among risk factors for angina. How is homocysteine related to the heart? Or the coronary arteries? How do these relationships make it a risk factor for angina? ...
9
votes
1answer
144 views

Protein data bank syntax: Can two protein secondary structures “overlap”?

I have a technical question regarding the syntax in Protein Data Bank files. In the protein with PDB# 1AE9 (pdb file), there are two lines in the .pdb file: ...
2
votes
1answer
280 views

Ammonia smell after physical exercise? What is the explanation? [duplicate]

After exercising vigorously one can sometimes smell ammonia and it feels like it's coming from within the nose actually. There is no indication that others can smell it when I do (i.e. seems to be ...
2
votes
0answers
78 views

Would my hands sweat this much if I wasn't wearing gloves?

I've wondered about this for a long time, and hopefully someone here has a reasonable answer. I'm a cell and molecular biologist, and much of my time at the bench is spent wearing (usually nitrile) ...
4
votes
1answer
329 views

What causes instinctive behaviour?

Some actions, almost behaviour, exist that are common across a species. For instance, based on personal observation, human babies try to taste anything new they encounter until they are a few score ...
6
votes
2answers
18k views

What is the function of the RNA primer in DNA replication?

During DNA replication, RNA primase puts an RNA primer in the lagging strand. What is the function of this RNA primer? Why can't the enzymes put DNA fragments directly?
3
votes
2answers
646 views

Does finite rate of increase depend on mortality of individuals in a population?

As written in my lecture handouts, there two main factors in the Geometric Growth Model of populations: $R_{0}$ is the expected lifetime reproductive output. This way, for unicellulars, for example, ...
6
votes
1answer
462 views

What happens to an ant colony when the queen dies?

Does the colony collapse? Do workers keep following the last orders? Or can future queens replace the dead one? I'm guessing this might also depend on each specific sub-species.
2
votes
1answer
113 views

What kind of mushroom(?) is this?

I found groups of these growing in the Lassen National Forest (Susanville, CA, USA). It looks like some sort of mushroom. I have Googled extensively, but can't seem to find a match.
2
votes
0answers
52 views

Why do conker flowers grow upwards?

Most trees I know that have their flowers in groups hang these groups down. I noticed, however, that conker flowers grow upwards! I guess that growing against gravity requires special effort, so ...
3
votes
1answer
1k views

How do liver and lung metastases cause death?

Metastasis to the liver and lungs are the main causes of death in colorectal cancer.(1) I understand that colorectal cancer may have metastases. But how do these metastases cause death? Reference ...
6
votes
1answer
122 views

Why does getting certain chemicals in cuts hurt?

More specifically, shampoo. What are the mechanics of detecting a noxious chemical stimulus in terms of which receptors recognise what, how do they do it, and how is this information relayed to the ...
1
vote
0answers
33 views

Are there precedents for considering that the coral reef biome has higher biodiversity than rain forests?

I've found conflicting references on which biomes are the most biodiverse ones. Also, which are the measures of biodiversity? Average number of different species per volume?
8
votes
2answers
105 views

Where can I find historical data on world-wide ecology parameters?

I hope this is the right StackExchange forum for such a question. I'm looking for large data sets on world-wide ecology parameters, such as annual temperatures by latitude, annual rainfall, CO₂ and ...
5
votes
2answers
290 views

What medical and commercial proteins are made using genetically modified animals?

Recombinant technologies in micro-organisms being used to produce commercial and medically useful proteins like insulin are fairly common. However some proteins are still produced commercially in ...
1
vote
0answers
58 views

Are there any examples where 'magic bullet' drugs have worked?

Magic bullets are drugs that can be administered on a micro local scale near the tumour by exploiting the different surface antigens that cancers expose. The drug attaches via an mAb (attached to the ...
5
votes
1answer
232 views

Experimental evidence for the selfish gene vs. the selfish individual

In the Selfish Gene, Dawkins makes the argument that a better view of evolution (i.e. more in accordance with experiment) is obtained if you view the basic unit of evolution to be the gene rather ...
7
votes
4answers
298 views

Can sexual reproduction create new genetic information?

Is there a small chance that in sexual reproduction a new allele forms in the off-spring that was not present in either of the parents, or are the alleles in the offspring always from at least one of ...
1
vote
1answer
31 views

cell uptake prediction

I'm generating random molecules I would like to know if they are able to pass through the cell membrane. Are there any ways (preferably computational) to predict cellular uptake of an organic molecule ...
9
votes
2answers
379 views

Is there any recent evidence for the aquatic ape theory of human evolution?

aquatic ape theory suggests that many features that distinguish humans from their nearest evolutionary relatives emerged because the ancestors of humans underwent a period when they were adapting to ...
7
votes
1answer
199 views

Why are some menstrual cycles irregular?

A friend of mine asked me this today, and I didn't know. I remember studying the menstrual cycle a few years ago, but I can't remember the details (other than it was very hormone-related), and so I ...
2
votes
2answers
808 views

What is in the space between neurons in a brain?

When neuron animations are displayed, there are frequently seen neurons, axons arranged in a lattice with a lot of empty space between. I'm interested if there is indeed empty space in the brain, or ...
1
vote
0answers
156 views

Does brain activity generate heat gradients in the brain?

I'm reading this article on guiding axon growth using temperature gradient, and it mentions that the trajectory of growth of neuron connections can be influenced by temperature gradients as little as ...
4
votes
1answer
507 views

How do I view the simulated protein structure along with ligand in VMD?

I did a simulation of a protein-ligand complex, and it has stabilized after 5 ns. I have got the respective pdb files for every ns, but when I try to view in VMD (Visual Molecular Dynamics), I cannot ...
1
vote
1answer
40 views

In vitro enzyme production

I need to express a protein in vitro but I don't know where to start. I will likely do a T7 transcription protocol but for translation I am not sure what to do. Are there any good kits?
2
votes
1answer
711 views

Do male marsupials have a pouch?

Do male marsupials have a pouch, or is it a female organ only (like the womb)?
2
votes
1answer
158 views

What is this marmot-like animal (Tigray, Ethiopia)?

I was searching what are the animals I frequently saw in the north of Ethiopia. I took some bad quality pictures. For me it looked like a large squirrel, local people called it a rat, and on the ...
5
votes
1answer
162 views

What effect do oligosaccharides, like those found in legumes, have on the composition of intestinal flora in humans and if so how so?

I know that intestinal flora metabolising oligosaccharides, like those found in legumes, is the cause for the well known fact that legumes cause flatulence, but does an oligosaccharide-rich intestine ...
1
vote
3answers
202 views

Has medical progress stopped human evolution?

We can cure many diseases nowadays, and thus the natural selection is very limited. Plus, mankind spent the whole beginning of its existence in almost the same hostile environment, and that's where he ...
0
votes
1answer
33 views

First genomic survey of human skin fungal diversity

"The researchers found that a single type of fungus, belonging to the genus Malassezia, is predominant on the head and trunk. Hands, which harbor a great diversity of bacteria, are home for relatively ...
2
votes
1answer
49 views

What does “rapamycin-sensitive oncogenic transformation” mean?

Can someone explain exactly what "rapamycin-sensitive oncogenic transformation" is? I get that it's a drug that suppresses the immune system but what does it have to do with oncogenic transformation? ...

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