All Questions

8
votes
0answers
86 views

Using the IMGT/GENE-DB service to find RSS

I'm trying to get the data for the Human and Mouse 12 and 23 Recomination Signal Sequences (RSS), to run a classification algorithm on it. I'm not a biologist, so I apologise in advance for my ...
7
votes
0answers
99 views

How does Sodium Valproate cause neural plasticity

I have been reading a fascinating paper: Valproate reopens critical-period learning of absolute pitch 18 individuals were given Sodium Valproate (VPA) for a fortnight during which they trained on a ...
6
votes
0answers
68 views

effect of pupil responses on the electroretinogram

The electroretinogram is generally considered to reflect the retinal processing of a light stimulus, typically a photoreceptor response followed by secondary neuronal activity. However, I am wondering ...
6
votes
0answers
103 views

Calculating additive variance, heritability, and percent of variance explained by additive effects

I've set up some dummy data in R which makes 40 genetically related lines (in this case I'm simulating hemiclones - they share one haploid copy of there genome within a line, thus additive genetic ...
6
votes
0answers
78 views

Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
6
votes
0answers
89 views

Neuroendocrinal mechanism of parturition

My book reads, "The fetus signals that it is mature by secreting certain hormones that diffuse across the placenta into mother's blood and cause the secretion of oxytocin from her posterior ...
5
votes
0answers
36 views

How to define “Quasifixation” in continuous approximation of finite population?

Background Many models including the famous very first models derived by Sir Ronald Fisher in his early career, assume infinite population size. In an infinite population, an allele can rise in ...
5
votes
0answers
55 views

What are the effects of long-term liquid breathing?

I just saw a recent Physics question that mentioned liquid breathing (which I had never heard of before) and I started to wonder about its long-term effects. Let's imagine a person underwent liquid ...
5
votes
0answers
165 views

Cytoplasmic determinants - protostomes and deuterostomes

Cytoplasmic determinants are spread unevenly in the egg, and so when embryo starts forming (cells start dividing), the determinants are also unequally divided between cell. This unequal distribution ...
5
votes
0answers
88 views

Model for fluctuating selection

Is there any mathematical model to predict the behaviour and long-term consequence of counter-acting selection at different time scale? For example, let's consider the bi-allelic gene $A$, with ...
5
votes
0answers
50 views

Honeybee decision process: new food, new home, new threat

I have heard that honeybees send out scouts, then based on the scout reports more bees go then come back and report and so they are supposed to be efficient decision makers. Can you give as complete ...
5
votes
0answers
265 views

Reason for seeing grid-like patterns when strobing a solid black-white image?

I was trying to do some stimulation for SSVEPs by strobing a solid black square and a solid white square. Weird thing was, I ended up seeing weird grid like patterns that looked like this, always of ...
5
votes
0answers
90 views

Do mammals develop tolerance to anticholinergics?

I know that first generation H1 antagonists, commonly known as antihistamines have anticholinergic effects. Their sedative side effects go away due to tolerance, but as for their anticholinergic side ...
5
votes
0answers
116 views

What temperature should mammalian B-Cells be stored at outside of the incubator?

I'm working with murine B-cells. The general protocol is to keep cells on ice to keep them from dying but I've noticed that it makes these cells aggregate and precipitate out. I've heard suggestions ...
4
votes
0answers
26 views

Why does a pacemaker have a negative pulse?

Why is the first phase of the pulse from a pacemaker cathodic?
4
votes
0answers
11 views

Would constant light or fading light be registered as more wakefulness promoting by the Supra Chiasmatic Nucleus?

During the fall and winter season, a number of people are experiencing Seasonal Affective Disorder. One of the way it has traditionally been treated is with a dedicated lightbox - a very high ...
4
votes
0answers
38 views

Hill's function for translational regulation

Transcriptional regulation is generally modeled as a Hill's function (similar to Michaelis-Menten Kinetics): $$\frac{dm_X}{dt}=\alpha _{m_X}.\frac{R}{K+R} -\beta _{m_X}.m_X$$ Where $m_X$ is the mRNA ...
4
votes
0answers
76 views

What is this fuzzy, black fungus that grew on my plates in the 4⁰C room?

I often find the fungus below growing on my (ostensibly) sterile plates in the 4⁰C room. Presumably it takes a few days to reach this size. The colony looks puffy and dimpled in the middle, like a ...
4
votes
0answers
46 views

Can microdialysis be made in Drosophila melanogaster?

I've asked this before in stack overflow's cognitive science community, and someone recommended me to ask here: I've found a couple of studies using microdialysis on insects, but didn't found any in ...
4
votes
0answers
26 views

Why doesn't Clopyralid damage cool season lawn grasses?

I use Clopyralid (3,6-dichloro-2-pyridinecarboxilic acid) to kill broad leaved weeds in lawns. From my understanding, it works by mimicking an auxin which affects plant growth. Naturally this pulls ...
4
votes
0answers
41 views

How does the frequency of a visual stimulus affect the steady-state visually evoked potential?

I want to make a project for EEG signal processing, and in my research I found the concept of SSVEP, which means that if you have a stimulus with low frequency applied to the eye, the electrical ...
4
votes
0answers
75 views

How do duplicate brain regions (ex: left/right amygdaloid body) operate together?

I frequently hear talk about parts of the brain like "Amygdala" or "Hypothalamus", so I looked them up in an app called "essential anatomy". What I see is that there's mirror symmetry, and most of ...
4
votes
0answers
87 views

Does Lucid Dreaming decrease the regenerative effect of sleep?

After watching this SciShow video on sleep, I wonder about lucid dreaming. Specifically: Does lucid dreaming and associated directed agency within Lucid Dreaming decrease the regenerative effect of ...
4
votes
0answers
55 views

Reformulation of Hamiton's rule

Who (and in which article) was the first to reformulate Hamilton's rule using the letters $B$ and $C$?. See below comments on this reformulation. Hamilton, in his 1964's article gave a mathematical ...
4
votes
0answers
76 views

At which step apply a detection filter when preprocessing microarray data? (Before/After normalization, batch effects removal)

I am trying to understand what is the best practice when preprocessing microarray data using a detection filter (on scanner p-value). Suppose I have a microarray dataset that I have to normalize with ...
4
votes
0answers
148 views

Genetic expression in interspecific hybrids

Referring to interspecific hybrids, I have the following two questions:- Quoting from wikipedia:- The offspring of an interspecific cross are very often sterile; thus, hybrid sterility ...
4
votes
0answers
50 views

Does DHA increase the effects of clarithromycin?

I've read on this publication that every drug that induces CYP3A can reduce the effectiveness of clarithromycin. Clarithromycin inhibits CYP3A. But it does not say anything about the opposite ...
4
votes
0answers
33 views

Are there any online resources one can use to access raw clinical trial data without having to contact those involved in the study?

I want to do some statistical analysis and I have a preference for real data so I was wondering if there's somewhere I can get such data for free without a heap of bother in phoning other those ...
4
votes
0answers
59 views

How significant is RNA degradation with removal of cap/polyA's in eukaryotes, or UTR's in prokaryotes?

Question is rather self-explanatory, but segmented into two parts. I'm attempting to make use of a repression system that employs cleaving RNA at specific areas with ribozymes with the intent of ...
4
votes
0answers
56 views

Does preservation in ethanol alter leaf litter mass?

I have benthic samples that were collected with an Ekman dredge from some small ponds. The samples contain quite a bit of coarse particulate organic matter (CPOM, basically dead leaves). I would ...
4
votes
0answers
84 views

What controls leaf senescence in deciduous tree species, and how can I predict it?

If I want to predict litterfall, what data do I need to collect, and what statistical model might I use? For example, I might use the following coding to record phenological stage every other day, or ...
4
votes
0answers
66 views

What is the frequency of double-hets between parent and child?

Say both parent and child are genotyped for all SNPs. In this setup we are only looking at variant positions between one parent and child - so neither parent nor child are homozygous reference (no ...
4
votes
0answers
53 views

Does a mydriatic drug neutralize the action of a miotic?

If a person were administered a mydriatic, would the subsequent application of a miotic neutralize the action of the former? If the sequence were reversed would a mydriatic neutralize the effect of a ...
4
votes
0answers
68 views

effect of background selection on promoter regions compared to distant enhancers?

Has anyone looked at the effect of background selection on the levels of conservation of promoter regions compared to distant enhancers? Do promoter regions have a higher conservation due to ...
4
votes
0answers
100 views

Dimensionless number for blood volume

Comments from the question How is the blood volume of a living organism measured without killing it? by @Nico discussed that the time of blood recirculation scales with the size of the organism. I was ...
4
votes
0answers
82 views

What is the distance between the 3' 18s rRNA (the Kozak consensus sequence) and the A-site of eukaryotic ribosomes during protein translation?

Reposted from Quora http://www.quora.com/What-is-the-distance-between-the-3-18s-rRNA-the-Kozak-consensus-sequence-and-the-A-site-of-eukaryotic-ribosomes-during-protein-translation The Kozak sequence ...
4
votes
0answers
39 views

RHEB senses amino acids in order to recruit mTOR. Do we know if RHEB is more sensitive to some amino acids (like methionine) than other amino acids?

See http://www.ncbi.nlm.nih.gov/pubmed/21157483 for the full paper describing the process of how RHEB recruits mTOR. We also discussed this in Matt Kaeberlein's class yesterday and I posed this ...
4
votes
0answers
43 views

Serological assays not detecting native proteins

Is there anyone out there who has done much work with serological assays? We have antiserum for a manufactured viral protein but no luck so far getting it to detect native protein (unless today's ...
4
votes
0answers
108 views

If D1 receptors stimulate adenylate cyclase (through GPCRs) and D2 receptors inhibit it, then why do mutations in both have similar effects?

D1 and D2 both refer to specific types of dopamine receptors. I'm sure it has something to do with the fact that the D1 receptors are in regions different from D2 receptors. I know that adenylate ...
3
votes
0answers
92 views

Evolutionary reasons why you cannot tickle yourself but masturbate

There are obviously good reasons that explain why you cannot tickle yourself (see e.g. here). This got me thinking why it is possible to masturbate... Wouldn't it make more sense to not being able to ...
3
votes
0answers
47 views

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

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 ...
3
votes
0answers
16 views

B cell receptor editing

If a B cell contains two mu chains and two lambda chains and is self reactive can it go back and rearrange its kappa light chains? I'm not sure if it can only try to rearrange its lambda light chains ...
3
votes
0answers
19 views

Mechanisms of Gene*sex / Genotype*sex interactions

I'm looking for suggestions of the mechanistic level at which genotype/gene * sex interactions can occur. These give different phenotypes from the same geneotype dependent on the sex they are ...
3
votes
0answers
29 views

How many eukaryotes are there on Earth?

I have been reading: William B. Whitman, David C. Coleman, and William J. Wiebe, "Prokaryotes: The unseen majority", Proc. Natl. Acad. Sci. USA 95, pp. 6578–6583, June 1998. [Full Text] [PDF] ...
3
votes
0answers
28 views

Biological age of grafted plants

Suppose you graft a piece of an existing 'old' plant. Will it continue to grow having the same biological age as its parent? I.e., would it die at the same time as its parent? Or would the process of ...
3
votes
0answers
11 views

How does anadromous fish physiology “know” to switch from salt to freshwater and back?

What mechanism allows anadromous fish to switch from salt to fresh water and back? How does the fish "know" to switch its physiology and do other fish possess the biochemical machinery for this? How ...
3
votes
0answers
36 views

How many pandas should exist?

I have a degree in Biology so I'm a little embarassed that I never learned this, but... How do we know 1600 Pandas isn't enough? I know that we have historical numbers (although I couldn't find ...
3
votes
0answers
45 views

Does eating antacid (such as Magnesia) before meal have any impact on digestion?

During an anatomy lecture I heard of the importance of the acidity of gastric acid (e.g., killing microorganisms, dissolving food, being a factor for triggering further processes). If a healthy person ...
3
votes
0answers
24 views

More extreme phenotypes when parents are from diverged populations

In quantitative traits we have many loci affecting a trait. If we took a bunch of parents where all mothers and fathers were of a certain value at the upper end of a trait range, and then looked at ...
3
votes
0answers
29 views

Which organs in the body are responsible for measuring temperature?

As an instrumentation engineer, I have designed temperature control systems capable of measuring and controlling temperature with a precision of 0.001K over a wide temperature range. I have always ...

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