DISENCHANTED DICTIONARY

When human body cells are removed and put into a cell culture, they weaken and die quickly, usually within about 50 divisions. Without the rest of the support structure—a heart, blood circulating, a digestive system and so-on—body cells can't survive. Body cells also age, so even if you were to simulate the body's environment in a test tube or petri dish, the cells would eventually perish anyway. The basic mortality of the cells reflect the basic mortality of the organism they comprise, which is why there's no fountain of youth or medicinal procedure that'll give you biological immortality.

There is, however, one human being who is biologically immortal on a technicality, and her name is Henrietta Lacks. In 1951 she showed up at John Hopkins Hospital in Baltimore, complaining of blood spotting in her underwear. Samples were taken of her cervical tissue and sent to a lab for analysis, which came back with a diagnosis of cervical cancer.

The cancer was caused by the Human papillomavirus, which is a sexually transmitted disease. Most variants of this virus are harmless, but some are known to cause cervical cancer, as in Henrietta's case. After her diagnosis and before attempts to treat the disease with radium, another sample from the tumor was sent to George Gey, who was the head of tissue culture research at Hopkins. Gey discovered that the cells from Henrietta's tumor would not only survive and multiply outside of her body, but they didn't age either. These cells were basically immortal.

And they're still alive, even though Henrietta herself died of the cancer on October 4th, 1951. Now, HeLa cells are about as common in biological research as the lab rat and the petri dish, and are still being grown in an unbroken lineage from the cells originally harvested from Mrs. Lacks in 1951. They're used in cancer research because a scientist can perform experiments on them that otherwise couldn't be done on a living human being. They were also used in the development of the Polio vaccine, making Henrietta somewhat of a posthumous hero to millions.

But say you're a scientist looking at HeLa cells under a microscope. They live independently of the body they came from. They reproduce (faster even than other cancerous cells). They consume, excrete, and do everything an independent living organism usually does. A thousand years from now there will still be HeLa cells multiplying and living, even some of the original cells sampled from Mrs. Lacks, even though Henrietta Lacks herself has long since passed away. Is this a new species?

In 1991 the scientific community decided it was, and blessed HeLa cells with its own genus and species: Helacyton gartleri, named by Van Valen & Maiorana.

That would make Helacyton gartleri an example of speciation, which is when a new species is observed developing from another. In this case, the development is from a chordate (homo sapien) to something that's more like an ameoba (a cross-phylum mutation), giving us an animal with a mostly human genotype, but which does not develop into a human-like phenotype. Since this event occurred in nature when the papillomavirus transformed Henrietta's cells, and not in the laboratory, it's a strong piece of evidence supporting Evolution (although not one that suggests you could go from an ameoba to a chordate, which would probably take more than one mutation).

is a deterministic entityD  categorized by MedicineD  categorized by BiologyD  

2004-04-24 21:54:15.480123-05

The modern word algorithm is derived from Abu Ja'far Muhammad ibn Musa al-Khwarizmi, one of the better known Persian mathematicians, mostly thanks to his book, Hisab al-jabr w'al-muqabala.

al-jabr, which means "completion" or "transposition", was later mangled into algebra, for al-Khwarizmi's book was the first we know was written on the subject. In al-Khwarizmi's time, algebra was a practical system for solving all kinds of problems "in cases of inheritance, legacies, partition, lawsuits, and trade, and in all their dealings with one another, or where the measuring of lands, the digging of canals, geometrical computations, and other objects of various sorts and kinds are concerned."

al-jabr was about removing the negative terms from an equation, while al-muqabala meant "balancing" the values of an equation across an equals sign. Like this:

50 + 3x + x² = 29 + 10x

which can be simplified to just:

21 + x² = 7x

(Zap the 3x on the left-side by subtracting it from 10x on the right, then zap the 29 on the right-side by subtracting it from 50 on the left.)

More on al-Khwarizmi and al-jabr is available at MacTutor online and Wikipedia.

is a self directing entityD  categorized by MathematicsD  

2004-02-14 13:53:10.098658-06

"I'm sorry I was rude, it's because I was in a hurry to catch a bus."

But when you watch someone else screw up you're more likely to blame it on their personality.

"He was rude because that's just the kind of person he is"

This is called the Actor/Observer Difference, where you (the actor) tend to blame your behavior on external factors (circumstances), but blame internal factors (personality/disposition) for the behavior of people you observe.

The difference is forged by how well you know yourself and the things that make you tick, versus what you know about other people. Since you have a constant awareness of the things that go on around you, there's a lot to chose from when it's time to blame something for your behavior. But unless you get to know somebody very well, or were paying attention to the things that might influence their behavior, you don't usually know what causes someone else to behave the way they do. So everybody else seems to be one-dimensional.

One phenomena that springs out of the Actor/Observer Difference is road rage. Since there aren't enough clues to tell you why other drivers behave the way they do, it forces your mind to view them as all a bunch of jerks.

is a behaviorD  categorized by PsychologyD  

2003-07-28 23:38:07.888182-05

Verb. To unintentionally boost an opposition's PR with a high-profile confession of opinion. To fuck up.

Noun. Verbal friendly fire.

is a activityD  categorized by WarD  categorized by JournalismD  

2003-03-31 13:48:05.966051-06

According to Aristotle's physics, every event has four causes, or aitiai in Greek:

1. material—what the thing is made of (“the bronze of a statue and the silver of a cup”),
2. formal—what the thing is (it is a statue, or it is a cup),
3. efficient—what made the event happen (an artist made the statue, a craftsman made the cup),
4. final—why the event happened (because the statue brought pleasure to the eye, because we needed something to drink from).

The final cause betrayed an assumption of Aristotle's time, which was that every natural event was initated by a god. Gravity was explained by saying that an object went to “where it needed to be”, and it was a god that chose that place.

Today, the word “cause” almost always refers to the efficient cause. Ships move because wind blows on their sails, the wind moves because of the existance of unbalanced high and low pressure regions, and those regions develop because the sun heats the atmosphere and the Earth spins on its axis and so-on. No motive needs to be provided for why these things happen, so there is no final cause.

is a traitD  categorized by CultureD  categorized by PhysicsD  categorized by MetaphysicsD  

2002-12-19 13:04:24-06

Person responsible for maximizing the overlap between the government's interests and the country's.

is a self directing entityD  categorized by PoliticsD  

2002-11-22 22:41:25-06

(“Kor-puss Cal-oh-sum”)

Your brain is so good at developing independent consciousness that it did it twice, once for each hemisphere (and quite possibly more). The reason why you're only aware of one “self” or internal monologue in your head is because the two distinct minds are orchestrated into a single personality by the corpus callosum, a cluster of nerves that connect the two hemispheres.

Fig 1: corpus callosum, just above the thalmus and below the cerebrum.

As you grow up, the corpus callosum is believed responsible for balancing the load of lerning tasks across each hemisphere, making each specialize in certain tasks they're genetically set up for, or are adapting for. In most people, for example, the left hemisphere deals with language and numbers, while the right deals with spacial relationships and aesthetics.

When not learning, the corpus callosum acts as a bridge that one hemisphere can call on the other to accomplish a task. Remembering that the imputs for the brain are switched left-to-right—that the right hemisphere controls the left side of the body and vice-versa—if the left eye sees a word, the right hemisphere will pass the word over to the left hemisphere for processing by the language centers. It is the conduit for a remote procedure callA, so to speak.

But what about those two separate minds again? In some patients with severe, drug-resistant epilepsy, surgery has been performed to cut the corpus callosum and sever the high level connection between the two hemispheres completely. When the patient is revived, some unique behavior can be observed by anyone who knows what they're looking for.

After recovery the patient will usually be able to go back to a normal life, capable of walking, running, holding a conversation, recognizing people and so-on. To a casual observer, it'd be as if nothing was wrong. But experiments can reveal the change in capabilities the surgeon's scalpel has done, and the effect is almost literally as if the patient's mind had been cut in half.

For a start, the patient cannot name an object he's holding in his left hand without looking at it. His left hemisphere deals with language, but it's picking up signals from the right-hand side of the body only, so it can't feel what's in the left hand.

The speechless right hemisphere is obviously still “awake”, has a memory, and is intelligent. If you flash a picture of say, a screwdriver to the left eye, and have the patient feel around in a darkened box for a corresponding object with his left hand, he's capable of finding either a screwdriver—if there is one—or a screw if there isn't. Or an ashtray if you show the left eye a cigarette. Or a toothbrush if you show a picture of toothpaste. This is clearly an indication of intelligence and memory, but while you're doing this, the patient is still incapable of naming either object.

While the corpus callosum can be severed, there are still lower-level connections between the two hemispheres, enough so that the patient can still coordinate actions such as walking. It's also typical, in most patients, that the left hemisphere is dominant and gets control over the body and the voice. It's as if it's still capable of telling the meeker right hemisphere to “shut up” when it needs to. But there's still a separate mind there, made even more obvious when it slowly learns basic language skills.

Even though each hemisphere specializes, they still retain the ability to learn other tasks, and in patients who've undergone this kind of surgery, that's more or less what they do. The right hemisphere can learn to read again, and in a way can start to communicate. Now if you flash the word “WALK” to the left eye (right hemisphere), the patient will get up and walk across the room. But let's say you stop him and ask him why he did this. You're using verbal language skills, and the response is going to come from the left hemisphere which has motor speech skills and “veto power” over the voicebox. The patient might say quite sincerely “I don't know!” or even “to get a Coke.”

In the latter, another interesting behavior is exposed. Sometimes the hemispheres, left without contact between each other, make up total BS to weave a consistent but false story about what the other side is doing. It may be a completely natural thing for each hemisphere to come up with its own style of narrative to explain one's own actions. The left will express it in words (the “internal monologue”), the right in images and sounds. They travel across the corpus callosum so fast that they seem completely unified, as if there was only one “me” there, even though, in reality, there are at least two. And perhaps more.

is a mechanismD  categorized by BiologyD  categorized by ThoughtD  also see Conversations with JoshuaA  

2002-11-11 23:36:11-06

Studying the skull to divine personality. The shape of the head, or the bumps felt on the scalp, were supposed to correspond to a map of the human brain, so one could presumably perfom such diagnosis as identifying a criminal before he commits an illegal act.

Phrenology stimulated research into the physical nature of the human brain and the discovery that there were, in fact, specialized structures. One of the first to be discovered was Broca's convolution—the motor speech center—by Paul Broca in 1862, after showing that a lesion in a patient's brain was causing aphasia.

Fig 1: Phrenological map, circa 1820

Phrenology is discredited today, especially since the practitioners of the craft were often also social reformers who'd weed out undesirables with the aid of a map like that shown in fig 1. The backlash to these dodgy pre-emptive morals gave the Tabula RasaD philosophy a boost, since as it turned out, wrapping a tape measure around someone's head or feeling for bumps was not an accurate way to determine innate behaviors—even if those behaviors really were there.

is a ideaD  categorized by PsychologyD  categorized by ThoughtD  opposite of Tabula rasaD  

2002-11-10 13:58:06-06

Literally “scraped tablet,” or the Blank Slate.

The theory that the human mind begins with no innate behaviors or knowledge at all, that every natural urge and instinct is programmed by society. The extreme interpretation is that absolutely nothing at all is hard wired, not even, say, the tendency to love. A more common interpretation is that all complex behavior—such as the tendency to violence, interest in music, skill at math, patience, phobias, desires and so-on—are learned.

John Locke (1632-1704) is usually credited with the idea in his Essay Concerning Human Understanding:

Let us then suppose the mind to be, as we say, white paper void of all characters, without any ideas. How comes it to be furnished? Whence comes it by that vast store which the busy and boudless fancy of man has painted on it with an almost endless variety? Whence has it all the materials of reason and knowledge? To this I answer, in one word, from experience.

As a way to explain human nature, the Blank Slate is most at home with anyone who thinks human beings are essentially interchangable. If you took a baby born to a family of musicians, you should be able to put her in a mathematician's family and expect her to grow up with great number skills, but no special inclination for music.

But that also means that a black child put into a white family should grow up with the same behaviors as a white child would have, and vice versa, making the Blank Slate theory a hidden assumption behind equal opportunity and affirmative action. If everyone is born with a scraped tablet, then all inequalities must be due to circumstance.

Which means that contesting the Blank Slate gets you in deep water, politically. What if it were discovered that race or gender X is, on average, worse at tracking moving objects than people of race or gender Y? Would one be allowed to descriminate against race/gender X for the job of air traffic controller?

And yet to people in certain professions—such as medicine and anthropology, where the differences between humans is important to know—it's obvious the Blank Slate theory is wrong. A pet cat raised by a human family will not grow up with human behaviors, but it will still chase mice and play with balls of yarn, even if it was never around other cats to learn these behaviors from. So there has to be some behaviors inherent, or hard-wired into the brain, and which can't be suppressed by the culture it's raised in. We can see this is true for cats, so why shouldn't it be possible for humans as well?

Children are clearly not born identical: they have different colored hair, eyes and skin, different facial shapes, different hereditary health problems, and so-on. So it's not unreasonable to suspect their brains might be different as well, and that the differences aren't limited to their IQ. Sure, you can get kids who are just plain smarter than others, but then you also get ones with clearly different behavior. Some kids tend to find math more fascinating than music, some more prone to violence, and it isn't always possible to explain these behaviors as a product of experience.

But that's one way that the Blank Slate had been so easy to defend: most kids inherit their environment from the same place they inherit their genes. You find a violent kid and visit his home to discover the father is violent, too. That certainly supports idea that the environment sets the behavior. But what if the father has a genetic disposition to violence? His son could inherit it, too.

categorized by PsychologyD  categorized by ThoughtD  

2002-11-07 23:05:43-06

Every web page you view is stateless, which means the web server treated every page request like a brand new summons for information, and one that had no relationship to any previous request or request that might come later in the future. At the low level your browser opens a connection to the web server, says "I'd like Page 2, please", receives it from the server, and then closes the connection. Every time this happens it comes as a complete surprise to the web server, which wasn't aware of any meaningful connection between that and the request for Page 1 it serviced a few minutes earlier. Likewise, when you ask for Page 3 later on, the web server hasn't taken special steps to anticipate it.

As a consequence, the authors of web pages have to build their own context and bridges from one page to another, hard-coding links from Page 1 to Page 2, from Page 2 to Page 3 and so-on. It isn't enough to ask the web server for “the next page” becuase from the server's point of view it'd be as if you'd started a conversation in the middle, and the poor thing had already forgotten what the beginning was. The author, therefore, is obliged to store the context—the state—on every page and re-create it on the server for every request.

That gets both awkward and expensive, and there are a lot of tricks authors resort to if they want the state to be richer than merely where you are in a sequence of pages. Shopping cart web sites, for example, all revolve around the way they've solved the problem of keeping state. Most use a session key approach, where a database on the server stores the state keyed to a unique number embedded into every page somehow, usually in a cookie that your browser stores. Every time you visit a new page on the site, the shopping-cart software—which the web server is invoking on each page request—matches up that number to the record in the database which stores what products you've put into your basket, and maybe also your shipping and billing address from a prior visit.

All methods can be broken. Some people don't like cookies and block them, forcing the site to try a backup scheme such as encoding the session key into the link address of every page. But if the user was to e-mail the address of that page to a friend, then the encoded session key would go with it and the friend might inadvertently hijack the session. There are all kinds of ways to try avoiding that scenario, such as invalidating a session if the session key suddenly comes from a different IP address, but even that breaks if both the original visitor and his friend are behind the same firewall or proxy server.

Another consequence of the stateless server is that it can't deliver updated information very easily. Since the connection is closed as soon as the page has finished downloading, the server doesn't know when you've stopped reading it. When you click on a link that goes to another web server, the previous one doesn't know you've just left, and if the information you were looking at (sports scores, stock prices, weather forecasts and so-on) has changed, then it can't contact the browser and give it the updates. This has also been awkwardly solved by page authors: they add an instruction to the page that tells the browser to automatically reload it after a few minutes. Unfortunately it's rather wasteful if the information hasn't changed by the time the page auto-reloads, and it can never keep up with live events.

An example of an Internet application that isn't stateless is a chat room. When you join a room on a server with many, the server remembers which room you're in and what name or alias you've given yourself. As the conversation progresses, the server only sends you updates to the rooms it knows you've joined, and it sends those updates to you in real-time because the connection has been kept open.

Being stateless isn't all that bad. The design of the web didn't anticipate shopping carts, but chosing a stateless design has vastly simplified the problem of writing a web browser and server (shifting the burden to web site authors instead, we guess). It also means you don't need a live connection (web pages can be delivered by email or stored on CD-ROMs) and you can cache some of the information to economize on bandwidth.

is a traitD  categorized by ComputersD  describes RESTD  

2002-09-02 20:48:10-05