Wednesday, November 30, 2005

Yes, the brain is a computer

An on-going and often acrimonious scientific and philosophical debate was definitively resolved today when the following structure--originally identified in 1979 in Pellegrino's rat brain atlas--was rediscovered:

(Louis J. Pellegrino, Ann S. Pellegrino, and Anna J. Cushman. A stereotaxic atlas of the rat brain. Plenum Press; 2d edition (1979). ISBN: 0306402696)

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Monday, November 28, 2005

One-handed typing

I'm working on the promised zombification post, but it's slow going, what with the one-handed typing on the Internets, and all.

Of course, I'm typing with my right hand while holding a purring Cat in my left--what else would I have meant?

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Who would ever have thought that zombification could be so controversial?

Some time ago, I promised a post on what I learned about the chemical aspects of zombification, as told to me by a chemist, no less. Since then, I haven't gotten around to writing it up, partly because I spend 3 hours a day every day commuting (not that I'm bitter or anything, mind you), and partly because I have access to the computer only when LL isn't using it for work.

But another big part of why I've procrastinated has to do with the controversy behind the explanation. It turns out zombification isn't nearly as cut-and-dried a mechanical process as I had originally believed. There is a lot of disagreement among scientists about whether and how it exists. Additionally, there are charges of racism against one of the most prominent investigators of the phenomenon, and I certainly don't want to be a part of spreading racist falsehoods out of ignorance (don't forget, Blog Against Racism Day is coming right up--Dec. 1!).

So as much as I hate "he said, she said" American journamalism, and think it's intimately tied up with a lot of the political problems we now have, I'm going to report on what I was able to find out, but I can't give the definitive word on which position is [closer to] the truth. In other words, in true creationist style, I'm going to "teach the controversy" on zombification. And while that, as we shall see later, does not have to be harmful, it can also fall way short of the mark as well.

First of all, with all due respect to Jon Singer (and that's a lot of respect!), we are going to have to agree to disagree about cassava. In my opinion--and I am speaking only for myself, mind you--anything which is responsible for degenerative ataxic neuropathy unless you prepare it "properly" is NOT a food in my book. The fact that there is a scientific controversy over whether the neural degeneration is caused by the cassava's cyanide, or by another neurotoxin also present is merely a sideshow (Mathangi DC, Namasivayam A. Neurochemical and behavioural correlates in cassava-induced neurotoxicity in rats. Neurotoxicity Research, 2000;2(1):29-35.).

I realize that subsistence farmers in sub-Saharan Africa are not in a position to have the same choices as I do, and cassava is an important part of their diet. In writing of the neurotoxocity of cassava, I certainly do not mean any disrespect to their history, traditions, and cultures. Nevertheless, there is a fairly large literature in PubMed about what can happen in the short- and long-term to individuals and populations when the cassava is not properly processed. I think that health care is a human right, and that that also means universal access to healthy foods that do not put you at the risk of neurodegenerative diseases. Still, I have to acknowledge that, given (white) Western attempts to stamp out other cultures, it is a very thorny question when you address traditional practices that may be harmful.

A similar issue is encountered among the Chamorro people of Guam--there is a disease found only there, lytico-bodig, which seems to be related in varying degrees to Parkinson's disease, Lou Gehrig's disease (amyotrophic lateral sclerosis, or ALS), and Alzheimers. Oliver Sacks wrote about it in The Island of the Colorblind, which I found a fascinating description which made me want to learn more and eventually be able to do something to help. However, Alexander Cockburn equates him with a supermarket tabloid writer. (I have yet to see Cockburn approve of anyone or anything, so whatever, Cockburn.)

One hypothesis of the origin of lytico-bodig (and I'm really skimming here, to get to the zombies) is that the ferny-looking-but-by-no-means-related cycads (hello, convergent evolution!) eaten on Guam have chemicals that cause the neurodegeneration. Further, there is now an article that links bat-eating to lytico-bodig--the idea is that the neurotoxin is consumed by cycad-eating bats and stored in their tissues, causing a biomagnifier effect when humans eat the bats. (Ince PG, Codd GA. Return of the cycad hypothesis - does the amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC) of Guam have new implications for global health? Neuropathology and Applied Neurobiology. 2005 Aug;31(4):345-53.)

Again, I'm very pro-bat, and pro-non-neurodegenerative-diet, but at the same time, I can't help but be aware of the issues of addressing medical consequences of traditional practices, especially with peoples whose options are limited.

The same issues of trans-cultural medical judgment apply when looking at the practice of eating fugu, or pufferfish, although typically the people who eat this species cannot be said to be lacking in options--fugu can be quite an expensive delicacy. But again, like cassava, it has to be properly prepared, or it will kill you--and properly prepared in this case means complete removal of the liver and ovaries in such a way that the tetrodotoxin does not remain in the tissues in sufficient amounts to kill you (although a slight tingling in the lips and tongue from the neurotoxin is said to be a delightful part of the gourmet fugu experience).

I've seen fugu at the Seattle Aquarium, and, like cassava, their toxicity puts them right out of the "food" category for me, although I do have to admit they are beautiful to look at. They are also the link from the previous discussion to the topic of zombification.

Wade Davis, an anthropologist and ethnobotanist, hypothesized that the Caribbean pufferfish are one of the active ingredients in zombie powder. According to his book The Serpent and the Rainbow, the vodou practitioner would mix up a powder containing (among other ingredients) tetrodotoxin from the cooked puffer fish. According to the chemist who related this hypothesis to me, it is like giving the victim a "chemical lobotomy"--the tetrodotoxin blocks the sodium ion channels of the axon, interfering with the action impulse to the muscles. But it doesn't cross the blood-brain barrier, so the victim remains conscious but paralyzed, aware of what is happening, but unable to do anything about it.

Allegedly, people have been buried alive in this state, although I can't verify that personally. What I can verify is that when I had four teeth pulled for braces, the dentist gave me general anesthetic, but started just a moment too soon with the tooth extraction. It was right before I went totally under, and so I couldn't move or cry out, but could only lie there as I felt the tooth ripped out of my jaw. Fortunately, either the anesthetic kicked in, or I passed out at that point--either way, the remaining three teeth were extracted while I was under. So I've got to say that the idea of zombies being aware of what is going on, yet unable to react, really freaks me out.

So, supposedly, the tetrodotoxin causes paralysis and decreases respiration and other bodily activity, to the point where the victim is supposedly pronounced dead and buried. Later, when the toxin wears off, the practitioner is supposed to disinter him, and use him as a slave--while the paralysis wears off, the neurodegenerative effets don't, and the victim remains impaired--thus the term "chemical lobotomy".

It is a simple and understandable scenario, but the more digging I did, the more questionable it became. Davis is accused in some circles of scientific fraud, and in others of racism in the way he wrote about Haitians. Scientists (among others, toxicologists) don't agree on whether zombies exist, or, if they do, whether the effects of tetrodotoxin are sufficient to account for them. Replication of the effects has been problematic, and people have distanced themselves from the controversy. Additionally, some researchers claim that the so-called zombies are mentally ill, not poisoned. Under this scenario, all the attention given to the tetrodotoxin hypothesis detracts from the real problems of schizophrenia, fetal alcohol syndrome, and other disorders.

So the answer is: I just don't know.

And because I can't say for sure, I am going to have to leave it at that unsatisfying point of reporting the controversy, but not being able to resolve it, or even to predict which way it will ultimately be resolved. It is an interesting idea: tetrodotoxin as chemical lobotomy via blocking the axon's sodium ion channels--but ultimately unresolvable at present.

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My Name Is Cat

So I'm sitting in the big rocking chair, minding my own business, when Cat comes over, and ever so casually sinks a claw into my leg.

I react in the way he wants to see, screaming and pushing him away.

He retreats a few steps, and is sitting there just looking at me and laughing to himself, when LL walks into the room. Not seeing him, she steps directly and solidly on his tail.

Karma's a bitch, isn't it, Cat?

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Monday, November 07, 2005

Ok, now they're just messing with me

In classification, such as the development of a taxonomy or an ontology and especially for computer systems, the problem of homonyms (the same term for two different things) is a big deal. An native speaker of English may understand that "bear" can refer to a large carnivore, the act of carrying, or the act of giving birth, but a non-native speaker learning the language for the first time may find such homonyms confusing, and a computer absolutely cannot navigate the different meanings of the string without further clarification.

One of the running gags on The Simpsons is the main characters' home town, Springfield. They always play it very coy about exactly what state it's in, and since so many states do have a city named Springfield, there's plenty of plausible deniability to go around. Springfield seems to be one of the most popular names for cities in the US, but whether it's Springfield, Illinois; Springfield, Oregon; or Springfield, Massachusetts, is hardly the issue--the fact that there are so many Springfields does not cause confusion, because the state makes it unique.

Except for Pennsylvania--Springfield, PA is a township in Huntingdon County. It's also a township in:

  • Bradford County
  • Bucks County
  • Delaware County
  • Erie County
  • Fayette County
  • Mercer County
  • Montgomery County
  • York County

Apparently, there is also a town in Fayette County that used to be called Springfield, but--perhaps perceiving that wasn't particularly special around here anymore--decided to change its name to Normalville, although from the looks of it, Modeville would have been more appropriate. (I'm punchy from writing about statistics all day; that joke probably isn't the least bit funny, except maybe to a stat geek, and maybe not even then :). So Springfield, Pennsylvania kind of shoots the whole "uniqueness" concept of classification to Hell with its homonymy.

My landlady (LL) and I went to see a folk singer Saturday night, and at the coffeehouse, they were selling apple dumplings the size of pot pies. I was quite impressed, and LL told me that they were influenced by the style of Amish cooking. Then, realizing I hadn't gotten around to seeing Amish country yet, she generously and spontaneously suggested we drive out there the next morning. It's an easy drive from the Philly area.

We set off the next morning, and LL was driving, I was navigating, when she told me that there's kind of an artists' community at Kimberton. I was looking for Kimberton on the map, when it was totally driven out of my short-term memory by a nearby town, right smack in the middle of Amish coutry, which caught my eye.

I found the name of the town Intercourse, Pennsylvania, most amusing, although LL was just looking pityingly at me like my sense of humor is totally childish. I was willing to cop to that--as an anatomy informaticist, it's probably true that all those bio classes have burned out my propriety receptors, so it might be just me. At least, I was considering that possibility, when I spotted the name of another nearby town on the map.

I wanted to show you on Google Maps, but neither its name nor Intercourse's is displayed on the map, as much as I zoom in or out:

Ok, fine, I'll go to Yahoo maps, where the name is indeed displayed, but covered decorously and coyly with a star, much like a tiny fig leaf:

My final hope was MapQuest, but once again, I was thwarted by homonymy:

That's right: Pennsylvania has two Blue Balls.

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