Then why do casinos make money?

This Nature article fits perfectly with my current neurology kick. Everybody's heard of Pavlovian experiments, where an animal is trained to produce a physiological response to a normally unrelated stimulus by repetition. In Pavlov's case, he simply rang a bell and fed steak, and over time was able to induce salivation by ringing the bell only.

That's all well and good, but this paper asks what happens when ringing the bell is only assigned a probability of bringing steak. They showed four of ten shapes to monkeys, and then allowed to look at either a green or red target. Each shape carried a probability with it of a reward being given for a red or green choice. They were then able to train the monkeys to select red or green based on the most likely outcome, given the shapes presented.

The paper focuses heavily on the neurons in the parietal lobe involved in probabilistic reasoning. That's where the statistics get a little too dense for me, but I find the concept interesting; they were able to demonstrate the region of the brain associated with logic based on probabilities, rather than proven results.

Real-life lab conversations.

Me: See, Lisa? That's how you build a good relationship with your PI.
Lisa: What, by making fart jokes?

~Fin~

Considering replacing my bench with a cot.

Sorry for the lack of posting; it's been a long week in the lab. Today, I set my record at four gels in one day. Something tells me I'll have doubled that record by April. Since I don't have anything intelligent to say, and I'll be gone to Toronto for the weekend, here's a funny comic I found on Pharyngula for the meantime.

Holy Frig, Newton!

Not only was Isaac Newton a belligerent jerk, he was also a religious nut. Back then, I guess, they were all a little religious, but this goes beyond the Liebnizian belief that God created calculus, et cetera. Trying to match the dimensions of the temple with the stars? I always thought Newton was a pioneer of purely empirical, non-religious science. I guess not.

More on the origins of life.

Yesterday, I read a fantastic article in Scientific American about the chemical origins of life. It started off with a review of the RNA world hypothesis, which essentially postulates that life began by the chance formation of a catalytic RNA molecule which had the ability to self-replicate. At this point, however, it has become obvious that the odds of that happening are so extraordinarily astronomical that it's almost certain that something else came first. Even in the famous Stanley Miller experiment, there were only amino acids formed; no sugars or bases. In addition, ribose has proved nearly impossible to synthesize under the prebiotic chemical conditions.

This all led to the metabolism-first hypothesis, the main subject of the article. It's a lot more general than the RNA-first hypothesis, and requires much smaller molecules. What it boils down to is an energetically downhill redox reaction of a mineral fuelling an uphill organic reaction, say A to B. A is eventually regenerated by a stepwise series of exergonic reactions; in other words, a rudimentary cycle. The hypothesis then says that chemical and physical interference with the reactions would cause them to find alternative routes to get back to A, forming more complex networks, and the opportunity to form catalysts. The author goes as far as saying that nucleotides originated as some form of catalyst or energy-producing reaction (after all, ATP is a pretty universal energy-storing compound). The jump to RNA would be made by the chance polymerization of nucleotides, something far far more likely than a de novo formation. And now we've got to the RNA world.

The argument that the article seems to have the most trouble dealing with is how this system of reactions stores information. The author suggests that the chemicals themselves store it in a "compositional genome," which is replicated by the diffusion of chemicals from one physical compartment to another. This theory leaves open the possibility of something like a chemical founder effect - a drastic change in concentration occurs, and a new network is formed. This would in turn allow for the selection of some chemical systems that are better able to grow in concentration than others, and there you have it: evolution. It's a pretty good theory, but it seems a little lacking because it doesn't specify the barriers that would separate these systems, since they would only travel by passive diffusion. How would a new cycle "pinch off" from an old one?

At any rate, it's clear that something that can clearly be defined as life occured before RNA. This sounds like a pretty damn good idea, but it needs a little more data and a little more theory. I'm too lazy right now to look up the actual papers. Maybe if I'm feeling particularly bored I'll read some and post about them.

Och aye, the McCat is slain.

On Friday, I took that test of all tests, that exhalted exam, that furious final, the rite of passage for millions of let's-go-to-med-school-because-I-don't-want-to-do-research science students around the globe, the MCAT. To be honest, it really wasn't that bad, including the studying. I suppose I can say that now, looking back, after a solid weekend of pretty much nothing but Guitar Hero, fast food, and beer.

I know I "symbolized [my] signature by clicking 'Yes' to the non-disclosure agreement," but there was a random question about oximes (yes, oximes, of all chemicals), and I ----in' NAILED it. Synthesized by hydroxylamine hydrochloride? Yuh-huh.

Sorry. I had to get that out.

However, today I had a scary few hours when I realized that I never clicked "save" during the written portion. I just let time run out. Today, however, my saviour Meg let me know that it automatically saves my answer when I move to the next section. Looks like Andy's movin' up from a J to a K. Ohhh baby.

Anyway, I just read an awesome Scientific American article about the origins of life, and how the RNA world hypothesis probably isn't right. Too tired to post about it right now, but it'll come tomorrow.

Braaaaaains

This man is brilliant. His talk makes me want to switch into neuroscience - and believe me, I loves me my bugs. It also just gets me all excited about the future.

Can you tell I'm addicted to the TED talks?

Sure beats my chicken-dance interpretation of bacterial glucose transport.

Interpretive dance is always something I've made fun of. It still is. This one's an interpretation of symbiosis by two Cirque-du-Soleil-style dancers with the great-grandmothers of all wedgies. It's pretty mesmerizing for the first few minutes, but come on. I'm all for the appreciation of biology as a beautiful thing, but this is a little over the top; on the other hand, I think it would be hilarious if someone got Christopher Hitchens and Richard Dawkins to do it.

The NEW design

I ran into Areiyu today. We talked about the Blog and how we both hated the layout and colors.
I decided to take a little initiative and select a more appropriate "template". I like this new template better although I was temped by others. I think the colors match the feel of summer.

Whoa!

Aaron, was that you? The blog . . . she's so different. What's 565? I kind of liked the microarray background. But this one's cool. The colour scheme fits with the whole microbiology thing. I think.