neuroscience - Is the minicolumn the unit of the neocortex?

There are many arguments for what the unit of the neocortex is. "Columns" seem to be the standard, but what exactly those are is extremely contradictory between individuals, cortical regions, and species. Often times, when a column is referred to, it's actually a functional column without any anatomical borders (such as Hubel and Wiesels ocular dominance columns). Sometimes, the "column" is semi anatomical, such as the rat barrel cortex. Other times, these functional columns are confabulated into anatomical units, without any evidence for a border.

So my question is, could Mountcastle's "minicolumns" be the actual anatomical unit of the cortex? I've heard arguments that they are mere developmental relics. But they seem like the only reliable and consistent unit in the cortex.

physiology - Why is the human body able to repair a broken bone and not a heart muscle?

The heart does have stem cells in it, and there is cell turnover in the heart, of about 1% per year. Which is much slower than your skin, but not nothing. This allows your heart to grow during your life, and remodel itself slightly to become stronger/more efficient when you get in shape.

The heart can repair itself, when damaged it doesn't simply stay damaged. Unfortunately, the 'repair' leaves particularly useless scar tissue. After a heart attack, the dead muscle does repair itself, but very poorly. This 'scar' barely contracts, and isn't as strong as the heart wall around it.

This is mostly a function of the very specialized heart myocytes, and the evolutionary (relative) uselessness of being able to regenerate your heart after injury. In the wild, if your heart was injured, you were probably dead.

botany - 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 attempt worked which we will find out tomorrow).

What are any common problems or possible considerations that we should bear in mind when testing?

proteins - Two subunits connected by only one disulfide bridge: quaternary structure?

I've always simply assumed quaternary structure to be characterized by non-covalent interactions such as hydrogen bonding, van der Waals interactions and whatnot. However, if two distinct polypeptides were only connected by one covalent disulfide bridge, would this be considered as quaternary structure, assuming that non-covalent interactions between the subunits are either negligible or even repulsive?

In other words, can a disulfide bridge, on its own, convey quaternary structure?

On a side note, are there any notable examples of this type of interaction?

Last-ditch efforts to maintain thermal homeostasis

I was in the gym's steam-room today and a thought occurred to me: have I truly thwarted all possible mechanisms for maintaining thermal homeostasis?

There's sweating, which is thwarted because the steam-room's atmosphere is as close to 100% humidity as possible, so there's almost no evaporative cooling.

There's convection, which is thwarted because the ambient temperature is above normal body temperature.

And I can't get rid of heat by exhaling, because every lungful of air I inhale is already above normal body temperature.

I think that, eventually, I should go into hyperthermia, but beside the above, are there any other last-ditch attempts to lower core temperature that my body could take?

How can I normalize mRNA samples for sequencing?

Is there an easy, inexpensive, not too labor intensive way to normalise mRNA samples so that even though one loses information of gene expression levels, each of the transcripts in the transcriptome is equally represented in the sample for sequencing? This is to say, one has a uniform distribution of transcripts, so that the lowly-expressed transcripts still have a good chance of being sequenced.

I have seen a few papers mentioning protocols for mRNA normalization, but I can't tell if any of them are practical in real life wet lab situations.

cell biology - What's the distinction between a tetrad and a synaptonemal complex in meiosis?

As far as I can tell there is a distinction.

A tetrad refers to the entire group of four chromatids after they have come together for crossing over in Prophase I (synapses).

A synaptonemal complex as you would expect is formed in synapses. This is a protein-RNA complex that connects the intervening regions of matched chromosomes in some circumstances - it is not required. Mutated yeast that can not form this complex has still been shown to be able to exchange genetic information.

In other words, you can have a tetrad without a synaptonemal complex, but not vice versa.