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4

Note: This is based on literature searches I've done a while ago out of general curiosity. I'm in no way an expert on human reproduction. If I understand you correctly you are basically asking if there are any evidence for sex biases in offspring between families, that has a heritable genetic basis. This has been an active research topic for a long time ...


2

The question you're asking is essentially a version of an old riddle: If you flip a coin ten times and it comes up heads each time, what are the odds that the coin will come up heads when you flip it for an eleventh time? And of course the answer is that the odds are fifty-fifty. You could instead argue that 10 heads in a row is evidence that the coin is ...


0

Another lead are sleep spindles, closely related to the RTN as mentioned before. Basically the thalamus enters a state of high-frequency firing to a low-frequency synchronous one, thereby taking the cortex with it. Sleep spindles are slow-wave potentials as apparent on the EEG that block out the normal flow of peripheral sensory information from thalamus to ...


1

I hope you might edit your question to give examples of such comparative injuries. I'm trying hard to imagine an example of this phenomenon, but I can't. The human body doesn't have a tripwire, or a lower limit of injury under which it will not respond. Normally the body mounts appropriate defenses against all injuries from the very minor, like a paper cut, ...


9

An older answer that referred to the physiological feats of ancient humans, and why modern humans are wimps made me look up a couple of papers on running speeds a while ago. One of the examples used to support the statement that modern humans are "wimps" is a study of ancient fossilized footprints from Australia, which claim that the individuals making the ...


1

My experience that it depends on it. You sleep in cycles, each cycle has about a 90 min duration. I think the quality depends on how many cycles you ended. It seems like you need to sleep more by an interruption. Sleep was recorded on 10 nights in each of seven older subjects (mean age 55) and nine younger normal subjects (mean age 22). The duration ...


8

This question is at least two questions. Dividing cells In terms of a dividing human cell line, every time a division occurs the telomeres capping the ends of the chromosomes get a little bit shorter. Once the telomeres get short enough they act as a signal that triggers apoptosis, destroying the cell. There is some human-to-human variation in the initial ...


1

The meaning of the term microenvironment depends on the scale of the system that you're looking at. It's a sort of weasel word that loosely means "context" or "stuff in the immediate surroundings of the system of interest that has some kind of an effect on it". I've seen it used to describe everything from the chemical microenvironment of a cell (e.g. a ...


2

As someone who has dabbled in both biology and programming, I assume you are referring to the theoritical ability of functional programming to simulate organic behaviour from well defined input. From that point of view, our comprehension of the human cell behaviour is currently near stone age level. The astounding diversity of homeostatic and signaling ...


0

All the residues in a polypeptide chain tends to configure into their lowest potential energy state. except the peptide bond all the other bonds are free to rotate, alpha helix makes optimal use of internal H bonds. The overall structure is stabilized by H bond between the hydrogen atom attached to the electronegative nitrogen atom of peptide linkage and the ...


0

The ward 'itis'usually add with a ward to represent a pathological condition called inflammation.So,haepatitis means inflammation of haepatic cell.Usually it is caused by HAV,HEV,HBV and HCVirus.But if the cause of inflammation of liver cell by other pathogens like bacteria protozoa etc also called haepatites(less common).evev excess intake of table salt ...


1

There is an increase by abstinence. The within-subject variability of the semen sperm count (n), volume (v) and the total number of spermatozoa (N) was studied on 220 ejaculates from 36 normal subjects after an abstinence of 7 days or less. The three semen characteristics for a given subject were highly correlated with the length of ...


0

in our body 2types of temparature persists.1.shell temp. and 2.core temp. Core temp means the temp. inside our body wich is usually 1'F more than shell temp(temp our body surface). in case of hot weather if you take cold water it will reduce your core temp. which may give you some comfort ,but in case of cold environment if you drink water equal to your room ...


2

Hepatitis is a condition of the liver where the cells of the liver organ are inflamed. Most often it is caused by a viral infection, hepatitis A, B and C are all viral forms of the disease. Bacteria (and Fungi) can cause hepatitis of the liver, and two examples would be the Staphylococcal and Streptococcal bacteria. These can directly infect the liver, and ...


3

In general I'd say "left and right brained behaviour" is total nonsense. I guess the origin of this kind of claim is a bad press release or something. Let's start with something simple. Say hearing. When you hear a sound to your left ear, it is projected strongly to the contra-lateral side (right hemisphere), and weakly to the ipsi-lateral (left hemisphere) ...


0

Enzymes usualy have a relative narrow temperature optimum, for those of our body this is usually around 37°C. It is around 37,2°C in the morning and goes slightly up to 37,7°C in the evening (see reference 1 for details). The temparature optimum for most enzymes looks somewhat like displayed in the figure (from here, interesting to read): Enzymes are ...


1

If there is passive transport for each ion, then every ion will diffuse over the membrane until the concentrations will be the same, and the membrane potential will be zero. So there is active transport in the cell, which maintains the resting potential which is -63mV. So with the current concentrations the membrane potential will differ from this -63mV, ...


1

I agree with Armatus, however I feel his answer incomplete. Sodium (along with chlorine) is the most important ion in the blood if we are talking about osmolarity and water transport. Water wants to move to the high osmolarity places so its transport is mainly controlled by the transport of sodium through selective sodium channels. This is not just about ...


2

Chris is right, I just want to extend his answer a little bit more. The presence of corrosion and the corrosion speed highly depends on the concentration of the acid, which is very low (0.5% according to Chris) in this case (considering that ccHCl is about 35-40%). According to wikipedia the vapour pressure of water is about 2645 kPa while the vapour ...


0

I think the disadvantages are mostly economical in that region and so they has nothing to do with epidemiology. Possibly a long term effect can be, that the economy of the region turns from bad to worse, which can affect the healthcare too, but that's just speculation. The advantages are obvious, ebola is quarantined at some level, so these measures prevent ...


5

I think inf3rno's answer is very complete, so I will just be adding some notes that might help OP understanding what's happening. Say that we increase the intracellular concentration of potassium by 10 mM, a +1 valence ion which contributes to POSITIVE membrane potential. Let's say we do that, in an in vitro cell model, using a syringe with only K⁺ ...


6

I think this question has more to do with kinetics / transport phenomenons than biology, but that's okay, everything is connected especially my computer to the internet. ;-) The basic idea behind transport phenomenons is that there will always be a flux of quantitative properties (e.g. charges, particle number, entropy, volume, etc...) where the qualitative ...


2

Afaik you can describe the potentials between the two sides of the cell membrane using the Nernst-equation. Yepp wikipedia writes the same here. Membrane potential is a very important thing, because human cells require stable internal concentrations of Na+, K+, Ca2+, etc... in order to work properly. These concentration can depend on species, for example ...


2

This is a draft. How do the pharmacodynamics of the NSAIDs differ - -? Merck's manual ch. 36 to start little bit at an introductory level: The anti-inflammatory activity of the NSAIDs is mediated chiefly through inhibition of biosynthesis of prostaglandins (Figure 36–2). Various NSAIDs have additional possible mechanisms of action, including ...


2

What you might be experiencing is olfactory fatigue, the temporary, normal inability to distinguish a particular odor after a prolonged exposure to it. It's a form of neural adaptation, a change over time in the responsiveness of the sensory system to a constant stimulus. This adaptative mechanism might prevent the overloading of the nervous system. ...


0

Drink warm water, because calves choose the same! ;-) I don't think it has any significant effect on your health. You may get easier sore throat if you drink too cold, but that's all...


0

It may have to do with the cold water possibly lowering your internal body temperature; it is well known that at lower temperatures that your metabolism slows, but I'm pretty sure there isn't a detrimental effect; it'll go to body temperature in a few minutes. Edit: It may have to do with the urban myth that drinking water will cause fats and oils to ...


4

Prions are misfolded proteins with abnormal tertiary or quaternary structures. That grants them resistance (to some extent, at least) to proteases (1). Also researchers believe that prions are able to replicate (2), by changing the structure of other proteins. Regarding the gastrointestinal barrier, that isn't exactly true. It has been shown that small ...


0

I think that's more of a matter of linguistics rather than any scientific/physiological reason. For instance, in Portuguese, you wouldn't call legs to a cat or a dog's limbs. You would say they have 4 "patas" (roughly translated as "paws"). And calling them legs, in Portuguese at least, would be weird. When veterinary doctors refer to animal limbs, they ...


2

TL;DR the huge block of text: The innate immune system only recognizes certain antigens, called PAMPs. The activate immune system usually requires the immune system, but it can get around this in some cases. You're on the right track. Pathogen-associated molecular patterns (PAMPs) Innate immune cells such as macrophages and denritic cells ...


-1

Question: Why can't we just take enough pills to obtain these vitamins and minerals? My reasoning: There are about 45 essential nutrients, which you need to consume to be healthy and live. You can get all of them from food without thinking about them. I'm not sure if currently there are a lot of supplements on the market that contain all essential ...


2

That "red pulp" spaces you're referring are not blood vessels but, in fact, thyroid follicles that selectively absorb iodine from the blood for production of thyroid hormones and storage of thyroglobuline. So, they act as a reservoir of the materials used by the thyroid's epithelial cells, also called follicular cells, to produce thyroid hormones (T3 and ...


1

Your vocal chords vibrate to produce a tone, but your mouth shapes that tone into the sounds that make up voice. If your vocal chords fail or are removed, the electrolarynx can be used to vibrate the throat for you, but your mouth still needs to shape that sound into words. Because the electrolarynx produces a mechanical buzzing vibration, you get mechanical ...


3

Check out Van Der Pol (chaotic) oscillator. It can be used to model heart rhythms. If a stimulus is applied to the oscillator, it will return to the curved envelope discussed in the article. However, if "pushed just right", the oscillator's current state will be pushed towards the very center of the loop, and it will stop oscillating. This is the mechanism ...


1

You may want to look into "Evolutionary - Developmental Biology", which deals with how an embryo develops into a grown organism. Thus, by combinatorial specifying the identity of particular body regions, Hox genes determine where limbs and other body segments will grow in a developing embryo or larva. A paragon of a toolbox gene is Pax6/eyeless, ...


0

This is caused by a build up of ketone bodies in your blood which lowers the pH of your body and can cause bad breath. Ketone bodies are a response of your body breaking down fatty acids for energy instead of glucose when in a low food intake (fasting) state. This is also true for morning breath since your body has been in a fasting state. The way to prevent ...


0

If your cats/dogs had a choice they would prefer a diet rich in raw meat because that is what they will eat if they lived in nature. Dry feed is not their preference, I tried this by giving my dog raw chicken and beef and he went absolutely crazy for it. He was also more active and alert. For humans, switching diet is necessary in order to receive all vital ...


12

Because mammary glands define us (mammals), the genetics of the ability to make milk has been of interest.[1] Because we consume milk, we have a dairy industry. Because the industry places a monetary value to certain milk constituents, the genetics of milk component production has been a viable area of study[2]. Since you are talking of cream production, ...


3

Anti-oxidants affect human metabolism by altering the redox states of the cell and redox-regulated functions and signaling mechanisms. The following quotes are from The Redox Stress Hypothesis of Aging (Free Radic Biol Med. Feb 2012) More recently, in a major conceptual shift, ROS have been found to be physiologically vital for signal transduction, ...



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