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Saturday, May 26

I can see that the neocortex thing went off quite well, so I'll be following it up tomorrow with an equally cool recount of the other thing we discussed during that supervision - all about IQ.

In the meantime, a few quotations and other things. I was reading a thread on Slashdot about the 40th anniversary of JFK's famous 'Let's go to the Moon' speech. Someone mentioned the lyrics to Sleeping Satellite which I recalled being a pretty good early nineties song (1992, as it happens). What I'd never realised was that the song was actually about the unfulfilled promise of the race to the Moon...

Speaking of which, I read this sad statement about Russia's equivalent of the Space Shuttle, the Buran:

The completely automatic launch, orbital manoeuvre, deorbit, and precision landing of an airliner-sized spaceplane on its very first flight was an unprecedented accomplishment of which the Soviets were justifiably proud. It completely vindicated the years of exhaustive ground and flight test that had debugged the systems before they flew.

But this triumph was also the last hurrah. Buran would never fly again. The Soviet Union was crumbling, and the ambitious plans to use Buran to build an orbiting defence shield, to renew the ozone layer, dispose of nuclear waste, illuminate polar cities, colonise the moon and Mars, were not to be. Although never officially cancelled, funding dried up and completely disappeared from the government's budget after 1993.

Curses.

On a slightly lighter note, this column by a Labour parliamentary candidate is surprisingly amusing:

A general election campaign gives us the opportunity to focus on what it is that we hold dear in this unique country of ours. Our picturesque high streets, peppered with their quaint little branches of Gap, Starbucks and Dunkin' Donuts. The sound of Celine Dion blasting out of a Nissan Sunny as it screeches past the graffiti tags under the Daewoo hoarding. An evening spent at a Tex-Mex bar, sipping a Bud and watching the Miami Dolphins on Sky Sports Extra. These are sights that make this happy land so special, these are the things that make our culture and language so unique. Period.

/ forum / 09:16 pm GMT


Friday, May 25

For those of you who want to while away half an hour, visit Vectorpark - lots of very fun and imaginative puzzles and animation there.

I had an extremely interesting Evolution and Behaviour supervision a couple of days ago, discussing the idea of genetic imprinting. First a bit of background. In each of our cells, our DNA is made up of 23 pairs of chromosomes. You have 23 chromosomes from your mother and 23 from your father, and they are called homologous chromosomes because they essentially have the same function, but each of the chromosomes in a pair have slight differences.

On your chromosomes are specific sections called genes, which code for proteins and enzymes and so on - the cellular machinery. Whether a gene on one chromosome is expressed depends largely on the status of its 'twin' on the other chromosome - it might get overrided or it might override the other gene (this is all a vast simplification, but it'll do).

However. One pair among the 23 pairs are the sex chromosomes. If you're male, you have an X chromosome from your mother and a Y chromosome from your father, and if you're female you have two X chromosomes, one from your mother and one from your father. One of the ways in which genetic imprinting works is that (for instance) on the Y chromosome there might be a gene that always overrides the equivalent gene on the female chromosome, no matter what the female gene is. And vice versa, it can happen the other way around.

So a group of biologists in Cambridge wanted to figure out what imprinted genes there were. What they did was to get a rat embryo consisting of only a few dozen cells, and then genetically alter a few of those cells. The exact alteration they did depended on the sex of the embryo. For a female embryo, they extracted one of the X chromosomes and implanted an identical copy of the one that was remaining. For a male embryo, they extracted the X chromosome and implanted an identical copy of the remaining Y chromosome.

They only did this for a few of the cells because if they did it for all of them, the rat wouldn't grow. Anyway, the rats grew up, and the differences from the normal were astonishing. The female rat, which you'll remember has cells that have two identical X chromosomes, was normal sized, but it had a vastly larger sized neocortex volume in relation to its limbic system (I'll explain those terms in a moment). On the other hand, the male rat had a much larger limbic system than normal, with a reduced neocortex. The male rat was also physically huge.

Now, the neocortex could be said to be the 'advanced' part of the brain. It carries out what are called 'executive functions' such as decision making, inhibition of immediate desires and so on. The limbic system is the 'primitive' part of the brain - it controls the body via hormones. In 'primitive' animals such as reptiles, you'll find a limbic system but not a neocortex.

So what does all of this mean? Well, what is happening is that the female rats are getting a double dose of the genetically imprinted genes that reside on the X (the 'female') chromosome - which means that those genetically imprinted genes code for enlarged neocortex volumes. Conversely, the genetically imprinted genes on the Y ('male') chromosome code for reduced neocortex volumes. The larger your neocortex, the less dependence your behaviour has on hormones.

I should point out that we do not see these differences in normal rats or humans because we always have two non-identical chromosomes which effectively balances all of this out (I know that doesn't explain everything by far, but there you go).

What is going on (some say) is a evolutionary war between the X and Y chromosomes. The X chromosomes - the female sex - wants enlarged neocortex volumes for increased social functioning and, say, Machiavellan intelligence. The Y chromosomes - the male sex - wants smaller neocortex volumes and larger body sizes so that they can beat people up. What we have right now is a compromise.

Well. That bit of science didn't come out quite as bad as I thought it might.

/ forum / 09:06 pm GMT


Tuesday, May 22

Just put up a couple of new photos of Parker's Piece in Cambridge. The panorama came out quite nicely, if overexposed.

/ forum / 10:44 pm GMT


Monday, May 21

Interesting link from Slashdot about a wristwatch that can record everything you hear, 24 hours of the day. Naturally (and justifiably) people were up in arms over the whole privacy aspects but from my point of view, something like that wristwatch would be incredibly useful; imagine the snippets of conversation or the random thoughts that you have during the day that could be recorded by this watch.

And of course it wouldn't be too much of a difficulty to extend this to total-recording glasses, that record everything you see. This isn't an original idea, people have thought about these technologies for years, but we're finally getting to the stage where they're commercially feasible. As a transparency advocate I'm looking forward to seeing these glasses on everyone but I'm more than aware that there are huge obstacles in the way of their successful implementation. Talk about this in the forum discussion thread (incidentally, the forum has been getting more posts recently, it might be worth your while having a look around).

There's been a bit of a brouhaha online about a 19 year old girl who recorded her struggle against cancer in a weblog. She died a few days ago and since then it was discovered that she was completely fictional. It's very interesting how people have reacted to it, both individually and as a community.

/ forum / 01:04 pm GMT


Sunday, May 20

Spent a couple of hours going around Cambridge to various colleges taking photos. Had to try and avoiding looking like a tourist, what with the camera, since colleges don't want them wandering around their grounds while the students are (supposedly) revising for exams.

Weather wasn't brilliant and neither are the photos, but they're not bad. More details captions soon. I'm hoping to expand the whole Cambridge gallery to have an annotated tour of the city.

/ forum / 11:22 pm GMT


 
 
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