4
votes
1answer
82 views

Does playing music during sleep actually suppress rather than rouse the brain?

I've long been interested in the effect of music/sound on dreaming, and even built 2 apps that play music during REM period. Now I'm looking at this article about FMRI studies of a sleeping brain, and ...
1
vote
0answers
21 views

Is there a homeostatic setpoint for number of hours of sleep required by a human?

I've heard this TED.com talk about dieting and it mentions that there's a very definitive setpoint within the human brain about how much a human should weight. The speaker mentions that after as much ...
2
votes
3answers
152 views

Why do we dream?

Is there any specific reason behind why we dream. Why sometimes we are getting wierd and unusual dreams. Sometimes we cant even recall what we dreamt off. Why this happens?
0
votes
2answers
114 views

How to determine the actual flux in the human metabolic model of a cell line?

The problem to be solved is to determine what the flux values are for the different reactions in the human metabolic model. As far as I understand, a good way to do that would be to use gene ...
0
votes
1answer
20 views

To understand clearly extraintestinal diseases

Extradistestinal disease seems to prefer to "bowel" diseases, I think this is about diseases outside gastrointestinal tract so stomach. Consider diseases ulcerative colitis and Crohn's disease ...
1
vote
1answer
84 views

why can't we digest cellulose [duplicate]

I have a very tricky question....all the veg and fruit cells contain cell wall and it is made of cellulose when we eat how our body digest though we don't have the enzymes to breakdown 1-4 beta ...
3
votes
1answer
66 views

Chaos theory and population cycles

I have just begun to read about Chaos theory and have come across the statement that "Period three implies chaos." My question: Does any odd period imply chaos or only 3? If so, how can populations ...
1
vote
1answer
27 views

Correlating Ki values of pesticides to bacterial growth

Four pesticides P1 to P4 are reversible inhibitors of an enzyme E that is essential for the growth of a bacterium B. Their Ki values are given in the table below. Each of these four pesticides ...
1
vote
1answer
27 views

Correlating B-lactamase expression to absorbance

When penicillin-resistant bacteria are grown in liquid culture media, B -lactamase is secreted into the medium. The supernatant of such a medium can be assayed for B- lactamase activity. Culture ...
1
vote
0answers
37 views

Cambrian explosion and evolutionary arms race

I've seen many times mentioned in textbooks and popular articles that a reason of the Cambrian explosion is an 'evolutionary arms race' between predators and prey. But this isn't really a sufficient ...
1
vote
1answer
119 views

What is lack in sense of smell called?

People who lack the sense of hearing, vision and speaking are called Deaf, Blind and Mute. But what is the person called if he/she lacks the sense of smell? Is there any case like that?
1
vote
0answers
18 views

water stress expression markers in arabidopsis thaliana

So far I found papers that show studies using RNA arrays on whom they categorized water stress gene markers in root. Water stresses were reproduced by different protocols (manitol...) but always on ...
0
votes
2answers
39 views

Is there any format for official Physiological/Medicine answers? [closed]

Assume you have an exam which has 5 extensive questions and 60 minutes. You do not have time to cover most if you write everything in essay format. If you start to write essays, you do not really have ...
0
votes
1answer
24 views

What is splice junction pairs?

Splicing is a modification of pre mRNA when all introns are removed and exons are joined. What is a splice junction pair? It is two exons which connected together?
2
votes
2answers
75 views

Does neuroeconomics study the brain or study economics?

I'm trying to understand what neuroeconomics is. There are two possibilities for what it might mean. (1) The study of cognitive processes in the brain by applying basic principles of economic theory ...
0
votes
1answer
51 views

The contribution of stem cells to life extension technology [closed]

What do you think is the most powerful method to extend human lifespan? I want to extend human life span significantly (hopefully extra 50 years or more), so I was expecting that stem cell technology ...
2
votes
2answers
60 views

Maintaining purebred pedigrees and how to lessen chance of getting disease?

Many breeds of dogs are known for a high incidence of genetic disorders. German shepherd and Saint Bernard dogs are predisposed to developing a crippling condition called hip dysplasia. Q: What ...
0
votes
1answer
37 views

How many chemical species are on average in a typical plant and animal cell?

I want to know what sort of range there is on the number of different chemical species in a typical plant and animal cell. Failing that, some specific examples (with sources please). Thanks
4
votes
3answers
140 views

Fisher's Fundamental Theorem of Natural Selection

Ronald Fisher discovered what he, with humility, called the Fundamental Theorem of Natural Selection. This theorem says (in its modern terminology): The rate of increase in the mean fitness of any ...
2
votes
1answer
120 views

Why do genetic drift generates negative linkage disequilibrium?

The very first sentence of the abstract of this article are: "In finite populations subject to selection, genetic drift generates negative linkage disequilibrium, on average, even if selection ...
0
votes
2answers
44 views

about the direct intervention of a child's gender

Can we determine the gender of a child now,I mean,not randomly? There are equal amount of sperms with X chromosome and Y chromosome. Can these two kinds of sperms be distinguished easily? If yes,we ...
3
votes
1answer
45 views

How many centrioles/basal bodies are there in multi-ciliated organisms throughout the cell cycle?

I thought there were only two centrioles per cell, that convert to the basal body at some point during the cell cycle. I also thought there's one basal body per cilium, so I'm not clear on where the ...
0
votes
0answers
44 views

Replication of DNA in E. coli: what are DARS and RIDA?

I understand what is DnaA, its role in replication and the fact that it's only active when binding ATP. I don't understand what are DARS and RIDA and how they control the amount of DnaA-ATP:DnaA-ADP
0
votes
0answers
34 views

Sleep: a tale of two morning stimulants

According to "common knowledge", morning/afternoon exercise is "good" for sleep (in the long run) and caffeine is bad (less so in the morning). However, both of these stimulate the brain; exercise ...
3
votes
1answer
34 views

Is there a way to measure ATP usage in the brain similarly to fMRI?

Is there a way to measure ATP usage in the brain (or anywhere else) similarly to how fMRI works (measuring changes in iron resonance in oxygenated/deoxygenated blood)? Is there some sort of similar ...
0
votes
1answer
40 views

Which processes are included in the process called cells eating themselves?

I am reading about atrophy and I am thinking to which processes the phrase cells eating themselves refer to. Cells need something to survive these difficult times. To decrease protein synthesis ...
2
votes
1answer
38 views

Does Sirtuin protein family Sir2 work in low-calorie diet mostly?

I am reading about the protein family in relation to the prolongation of cell life. It is known that Sirtuins have been implicated in influencing a wide range of cellular processes like ageing, ...
1
vote
1answer
56 views

How to relate human metabolic model reactions and cancer drug targets / reactome items?

Trying to find a way to take a cancer drug (from CancerDR, for instance) and infer the metabolic reactions that are affected by it in the Human Metabolic Model. Essentially, I would like to know ...
0
votes
0answers
19 views

Does biotin affect downstream experiments, such as RT-qPCR?

I have two biotins--one of which is binding my RNA with cleavable bonds, and the other with irreversible bonds. Does biotin have an effect if it keeps its bonds with RNA? If it does, why is this the ...
2
votes
1answer
64 views

Why Can Varied Species Live Together in Particular Ecosystems?

Consider the following question: The Piney Woods of Eastern Texas is home to a wide variety of organisms ranging from the grass Longleaf Oats to coyotes. Which of the following best explains why ...
0
votes
0answers
26 views

The biological basis of inflamatory foods: the list of attributes and the concrete example of milk vs kefir

I wonder if anyone has some interesting matterial on the biological basis of inflamatory foods. I'm interested in pin-pointing the (in)complete set of (known) causes in the form of a list and maybe ...
1
vote
1answer
72 views

How does activation of adenylcyclase lead to increased cAMP and diarrhea?

I am trying find explanation for these mechanisms Tox plasmid -> exotoxin (enterotoxin) -> activation of adenylcyclase -> \up cAMP enterocytes -> release of H2O, electrolytes in gut lumen -> ...
3
votes
1answer
48 views

How do fish tolerate pH changes in water?

I want to know how aquatic animals behave as a natural indicator of the acidity in lakes and rivers. How do they tolerate these pH change?
0
votes
1answer
34 views

What is the maximum amount of different bacteria in the drinking water in Europe?

I am looking for a statistical amounts which are allowed. Some students say it is 0 for all bacteria, which I think is false. I found this USA source. I found there Total Coliforms (including fecal ...
7
votes
2answers
101 views

Why can white hairs get dark again?

I have learned (probably in high school?) that hairs turning white is caused by the part of the folicle which produces the pigment dying and being replaced by an air bubble. This sounds very ...
0
votes
1answer
434 views

Which processes are during the latent period of ventricular contraction?

The latent period is the time between the start of depolarisation and the start of contraction. I know that the contraction of ventricles starts after sufficient influx of Ca2+ and threshold ...
0
votes
0answers
28 views

To define the total Resistance of Systemic Blood Circulation

Some systems are in parallel so let's just call those like $R_{\text{lungs}}$. I got this formula $$R_{\text{total}}=R_A+R_a+R_c+R_V+R_v$$ where $R_c$ capillaries, $R_a$ arterioles, $R_A$ Small ...
1
vote
1answer
35 views

Sitting much, thrombosis and hypoxia

I am thinking the more reasons why sitting much lead to thrombosis i.e. clotting of blood in blood vessels and then hypoxia in the deep tissues eventually. What are the physiological mechanisms for ...
1
vote
0answers
43 views

Why does the arch of aorta coils?

My study materials use the word vesselcompression chamber of aorta to emphasize aorta's elastic property. The arch of the aorta only coils, not its straight part. I think the reason why the arch ...
2
votes
2answers
37 views

RNA secondary structure comparison

Do you know any program which can compare two and more different RNA secondary structures? I need find some (dis)similarities between lots of predicted secondary structures. And create maybe common ...
1
vote
0answers
16 views

Is a neurostimulation implant for the soft-palate component of obstructive sleep apnea plausible?

There are currently ongoing clinical trials for neurostimulation implants designed to keep the tongue from blocking the airway in obstructive sleep apnea. The nerves for this are in the neck and ...
1
vote
1answer
227 views

Amber eye color in Neolithic Africa

Given what we know of the genetics of eye color and their historical distribution, is it possible or at least plausible for a person born in the Horn of Africa during the early Neolithic (ca. 9000 ...
6
votes
1answer
84 views

is it possible to completely reconstruct a family tree by DNA comparison alone?

Having DNA samples of all or almost all members of a population of, say, a few hundred or thousand individuals, is it possible to draw the entire family tree of those individuals? (Let's not assume ...
1
vote
0answers
29 views

Voltage-gated Potassium channels in the action potential of cardiomyocyte?

There is one type of potassium voltage-gated channels open in Phase 1 too. Some call them early repolarization channels. I am not convinced that the channels are different in different phases: 0, 2, ...
0
votes
0answers
45 views

Why is the resting membrane potential of cardiomyocyte more stable than that of Pacemaker in Phase 4?

There must be some channels that keeps this very stable. It seems to be that the resting membrane potential of pacemaker cells is steadily increasing until the threshold voltage. I think the same must ...
0
votes
0answers
14 views

Why is Aorta sometimes called Compression chamber?

I find this statement that Aorta is called Compression Chamber in my study materials. Aorta can it keeps blood flowing it can accumulate potential energy for bumping and compression However, why ...
2
votes
2answers
79 views

Do humans have a “dominant” neurotransmitter system/sensitivity within their brain?

I've recently heard a podcast, in which Dr. Helen Fisher suggests that there are "4 broad personality types", and each one is associated with a particular neurotransmitter: The corresponding ...
2
votes
0answers
66 views

Which of the cell types commonly found in mammals has the greatest number of mitochondria?

This is basically a fun question, inspired by this answer on scifi.se. So, which cell type will have the greatest number of mitochondria? Obviously, I am talking about wild type, healthy individuals ...
2
votes
3answers
92 views

What do you see if you look at your own retina with the same eye? (optical feedback)

When you record a video while pointing the viewfinder towards the screen showing a live preview you create optical feedback: video example. An anoalogous effect occurs when you turn your microphone ...
0
votes
1answer
51 views

Regional circulation and Cardiac output? [closed]

I am reading my study materials and think what is the systemic POV here Regional circulation Blood flow within the tissue/organs based on the functional demands of the tissue. E.g. The ...

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