3
votes
0answers
46 views

What were the first neural systems like?

I'm curious about the origin of the neural network. I'm thinking perhaps once life evolved beyond the single cell organism, it needed a simple neural network to coordinate those cells, and cell ...
3
votes
0answers
26 views

Color perception vs shade perception demo

I can't seem to find one of the best demos I've seen of color vs brightness perception. It consisted of a rotating animation of earth made of red of bright red points on a dark green background. As ...
3
votes
0answers
38 views

Can dolphins actually communicate linguistically?

Humans use "language." By language, I mean the thing I am using right now to talk to you. I know dolphins and orcas have very complex communication systems and also seem to process linguistic and ...
3
votes
0answers
79 views

How did birds survive the KT impact?

As I understand it, the ejecta resulting from the K-T impact (also known as the end-Cretaceous or Cretaceous-Tertiary extinction event) re-entered the atmosphere all over the world; the heat from ...
3
votes
0answers
56 views

Criteria for compound action potential thresholds

As opposed to action potential thresholds (which are binary yes/no events), electrophysiological thresholds of compound action potentials are arbitrary. Mostly a certain noise level is picked and when ...
3
votes
0answers
28 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
62 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 ...
3
votes
0answers
38 views

How many cells are there in the apical meristematic tissue?

How many cells are there in the apical meristematic tissue? Looking at this picture... , I would tend to think that there are few hundreds cells in the meristem tissue. But I guess this is a ...
3
votes
0answers
26 views

Gibson assembly - primer design with A and T rich regions

I have question about Gibson assembly. I have done it several times and it always worked okay for us, but now I want to assemble together a fragment which has sequence like this: ...
3
votes
0answers
79 views

Understanding the meaning of $s$ and $t$ in a population genetics equation

Sewall Wright in this article (1937) at the end of page 313 gives the equation: $$\Delta q = (s+tq)q(1-q) \space\space\space\space\space\space\space\space\space(1)$$ This equation is an ...
3
votes
0answers
169 views

Questions about insects eating flour and living in the cracks of a wooden cutting boards

I have a large wooden cutting board which is used in kitchen mainly for preparing egg pasta. The wood type is Populus (poplar or aspen or cottonwood). The main ingredients used with the cutting board ...
3
votes
0answers
88 views

Which types of blood vessels can regenerate in humans/mammals?

Which types of blood vessels can regenerate in humans/mammals? From what I understand, arteries and arterioles can be created later in life, while this is not necessarily the case with veins. However ...
3
votes
0answers
80 views

At what rate do chromosomal rearrangements occur?

How often does chromosomal rearrangements occur? i.e. what is the rate of chromosomal rearrangements? I am interested about these kind of chromosomal rearrangements that are passed on to the ...
3
votes
0answers
18 views

Evolutionary motivation behind number of neurons in DCMMP

I'm studying neuro-anatomy right now and I was surprised to learn that there are only three neurons along the Dorsal Column Medial Lemniscal Pathway (DMLP) which relays mechanical sensations from the ...
3
votes
0answers
50 views

Does this “fleeing spiders leaving fields of webs” phenomenon have a name?

I have recently seen images of big areas covered in spider webs: After flood in Australia http://www.viralnova.com/spider-fields/ ...
3
votes
0answers
52 views

TV's so loud when I turn over

Scenario: I'm about to fall asleep with the T.V. on. Having completely forgotten that it was, no longer even hearing it, just before falling asleep I turn over with a 'fresh' ear and it's blaring. If ...
3
votes
0answers
125 views

Hoechst red and blue spectra - what does the red emission tell us?

I understand that the blue spectrum is emitted when Hoechst 33342 binds to nuclear DNA. But what exactly is the red spectrum telling us? I read that the red spectrum can be indicative of apoptosis, ...
3
votes
0answers
33 views

Do I need to use the same WT C57BL individual for back-crossing or can I use a new one for each generation?

I've just received heterozygote C57BL mice from COMP and I need to start back-crossing them. I've read many colony management protocols, but couldn't understand if I need to use the same WT mouse for ...
3
votes
0answers
56 views

Relationship between mN and mg in vessel contraction studies?

What is the relationship between mN and mg as the units involved to measure the changes in contraction? A tool most widely used is an instrument called myograph. In these exoeriments, either units of ...
3
votes
0answers
42 views

Why are watermelons sweeter in the center?

Today I had a slice of watermelon and when I reached the outer parts of the pulp I wondered why those are less sweet. Whether or not the sugar occurs in crystalline form in watermelons is still an ...
3
votes
0answers
38 views

DNA barcoding, querry regarding tree based (cluster) methods for species identification

I am working on success rate of DNA barcoding in identification of species using distance and tree based methods. Regarding distance based method, I have used Adhoc and species identifier and ...
3
votes
0answers
59 views

Total number of pleura in the exoskeleton of cockroach

Basically as far as i know cockroach consists of 10 terga and 9 sterna but what are the total number of pleura present in the cockroach. Pleura are situated between tergum and sternum of a body ...
3
votes
0answers
132 views

Accuracy of genome size estimation by flow cytometry

I'm working on a genome project and using an in silico k-mer analysis to estimate the size of our genome based on the available Illumina reads. The k-mer based estimate is consistent across a wide ...
3
votes
0answers
44 views

How can cells produce antibodies despite error-checking mechanisms in their genomes?

How can immune cells produce so many different kinds of antibodies with different variable regions if there are so many mechanisms inside the cells that try to keep the DNA sequence as constant as ...
3
votes
0answers
56 views

Are small CO₂ concentrations devastating to certain cognitive tasks?

A new study shows strong effects of what should be a negligible CO2 concentration. The paper "Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making ...
3
votes
0answers
122 views

Human female chest model or data representation?

I am looking for professionally used representation of female chest (I know how it sounds ;). Generally - a model comprehensive enough to effectively represent human chest, with focus on breasts. ...
3
votes
0answers
50 views

Inbreeding Coefficient and Coefficient of Relationship

Wikipedia gives the following formula to calculate a "path of coefficient of relationship" between an ancestor $A$ and an offspring $O$: $$\rho_{AO} = 2^{-n} \left( \frac{1+f_A}{1+f_O} \right)^{1/2} ...
3
votes
0answers
83 views

What is the main challenge in creating a chemical male contraceptive?

More than 50 years after hormonal contraception for women was invented, a contraceptive pill for males is still not available. With the obvious major biological differences in mind, why does it appear ...
3
votes
0answers
75 views

A day in Beijing is like smoking Only one sixth of a cigarette

This is the title of this blog post followed by this other good post. I'm particularly anti-tobacco-smoke, at the point of not always considering other pollution, and this article shows how this kind ...
3
votes
0answers
140 views

Gibson assembly using NeBuilder

I am supposed to construct a plasmid that contains features from two other plasmids. My strategy is to generate three fragments form the two other plasmids. I was encouraged to try Gibson assembly, ...
3
votes
0answers
232 views

Do Asian women have more difficult births than Europeans?

I recently heard a claim that Asians in general have more difficult births than Europeans. Is this true? I have found a few studies(1,2) on the effect of ethnicity on birth outcomes but they seem to ...
3
votes
0answers
84 views

Why don't surfactants destroy or incorporate into cell membranes?

How do surfactants remain on the surface of pneumocytes without (1) acting as a detergent or (2) the phospholipids getting incorporated into the membranes of pneumocytes... I'm guessing the answer ...
3
votes
0answers
25 views

What determines the thickness of Cornea?

In eye-operations such as Lasik and Femto, the thickness of cornea is key decision factor whether the operation is feasible. A normal thickness is between 500-600 µm. Cornea consists of a very special ...
3
votes
0answers
76 views

Could miniaturization be used to protect endangered large species?

In some animals (like dogs) size seems like it's controlled mostly by just a few genes (IGF1, and the genes that repress it). I'm curious: (1) Does other miniaturization takes a similar route (for ...
3
votes
0answers
66 views

What metabolic processes do dormant and ungerminated seeds carry out?

What metabolic processes does a dormant embryo in a seed carry out? Seeds will not germinate, either because of a lack of favourable conditions, seed hibernation, or because of a genetically ...
3
votes
0answers
49 views

Database of Medical Assertions

Can anyone point me toward a computationally-accessible database of medical assertions? I'm looking for something where each row in the database contains a single unit of knowledge. It could either be ...
3
votes
0answers
50 views

Why is this dry pepper fruit still “powered”?

Check out this photo of my pepper plant this cloudy morning: (click for full res) Usually (and this can be seen on 2 and a half of the 4 fruits in this pic) the fruits are "disconnected" from the ...
3
votes
0answers
38 views

Adenosine metabolism

Are adenosine or its catabolites increased in inflamed airways? How can I assess this? I am trying to use inhibitors for adenosine deaminase, xanthine oxidase, and purine nucleoside phosphorylase, but ...
3
votes
0answers
56 views

Nocioception (pain perception) in subcutaneous tissue

There seem to be no nocioceptors (pain and temperature sensitive nerve endings) in subcutaneous fat. there are nocioceptors and other receptors in veins running through fat, but these can be avoided. ...
3
votes
0answers
59 views

The Operation of tuning in the S1 layer of ventral model

According to my previous question in ventral Stream pathway and architecture, I want now to get a brief example about how the S1 layer is constructed. In other words, how all the simple units are ...
3
votes
0answers
354 views

Distinguishing between mitotic metaphase and metaphase II of meiosis

I'm sorry if this seems like a silly question, but I was brushing up on some cell cycle dynamics and realized that everyone was talking about the differences between metaphase I and II, and since ...
3
votes
0answers
31 views

Division of Polar Body

The first polar body formed after meiosis-I is completed in oocyte, may or may not divide. Why is the statement that "it may or may not divide"? Is it random ?
3
votes
0answers
62 views

Deducing synaptic strength from electron micrographs?

There are several promising techniques for connectomics based on iterative sectioning and imaging of tissue with scanning electron microscopes (e.g. FIB-SEM and ATUM) By looking at such micrographs, ...
3
votes
0answers
336 views

Virus titre and copy number of integration

If I need to preform a genome-wide high throughput screen using pooled shRNA library infection followed by deconvolution by deep sequencing, how would I determine the optimal infection rate at which ...
3
votes
0answers
30 views

Are there any enzymes synthesised by humans that specifically catalyse the hydrolysis of non-cyclic Imides?

Imides or dicarbonyl amides are an interesting class of compounds that includes the pharmaceuticals thalidomide, aniracetam and a few other drugs. These compounds, however, are cyclic and I'm ...
3
votes
0answers
60 views

Is there a realtime molecular clock within the genome to co-ordinate the developmental sequences in an embryo?

It is difficult to assume that the massive number of co-ordinated developmental sequences in a developing embryo is controlled by molecular signalling alone. Is anyone aware of a molecular or ...
3
votes
0answers
68 views

Iron metabolism in the brain

I did an expression profiling from publicly available RNAseq data for mouse tissues. While for liver and testes I am getting expected proteins in the top highly expressed mRNAs, for brain I am getting ...
3
votes
0answers
126 views

Good poly-A filtering rules or tools

I am aligning a large number of ESTs. It seems poly-A tails show in many different ways. In addition to occurring at the very end, they can be flanked by the cloning sequence one one end, or have ...
3
votes
0answers
223 views

Can someone explain the color-changing unit (CCU) to me?

I've been physically carrying out serial tenfold dilutions on samples of Ureaplasma to work out the color-changing units (CCU). As a definition, the CCU is the highest dilution at which there is a ...
3
votes
0answers
91 views

Eye color genetics

I am trying to find a model to link the phenotype eye color to its genotypes. I know that there exists a simple model from Davenport, which explains {brown,blue} eyes. Further, there is an extended ...

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