Tuesday, August 24, 2010

Aggravation

Ugh. This sucks. My computer is chronically overheating, and dying of it. I should get another processor fan. But my graphics card is also chronically overheating, which makes my screen go all wonky, and my network card is burned out so I have a USB-to-ethernet adapter, and it doesn't quite start up right, and when it does start up I get a weird message every time saying that an unspecified file can't be found (The file "//" cannot be found. Please make sure the path or directory is correct and blah blah blah), and I've got six other problems - that's not hyperbole, they have to do with jacks and compatibility issues between different programs and other startup things which I thought I had handled but mysteriously aren't - which are all beyond my ken and I'm pretty sure I've got bubble gum in there somewhere as a structural component. OK, that last one is hyperbole.

In short: I need a new computer.

Anyway. All this makes for an angry D, and writing is now too frustrating. Worst. Timing. Ever. I'm sure I won't be able to stand not writing soon, though, so this shouldn't be long. I give it 'til the end of September - which may sound long to you, but September is a busy month for me, between my dad's birthday and the accompanying family get-together, an engagement party for a friend, a housewarming party for another friend, and... and that's all my free time, pretty much, between the two jobs and all. So we'll see how it goes.

See you in October! Oh, and since I won't be posting just to announce it, it's almost a year since I quit smoking [cigarettes]! Happy Birthday, Dad!

Sunday, August 8, 2010

Excuses! And a prologue. Or a foreword.

Rawls' balls, I cannot do this non-weekend thing like I said I could. And now I can't even do the weekend thing like I said I could! The nice thing is that I can just say "seventy-hour work week", and know that I'm justified. The rotten thing is that there's actually a seventy-hour work week justifying it. Blargh.

So it turns out that the immune system is way the Hell more complicated than I thought it was. Also, I have been arguing on the internet, and that takes time away from studying things and writing about them. Hmm... need content...

Well, Jack informed me of a book called The Unimaginable Mathematics of Borges' Library of Babel, which is exactly what it says on the tin. I want to write about that some time soon. Ebonmuse informed me of something which shall provide fuel for another 101IT entry, so I want to write about that, soon, too. And I didn't even cover clotting in my blood overview, so I'll have to squeeze that in somewhere, because it's complicated and interesting! But I haven't written anything about any of those yet. Blargh again.

OK, so I guess it's time to bust out the, uh, "big guns". As foretold in the prophecy, I am working on another book, entitled Tabula Rasa: A Novel Approach to Epistemology. Here is the prologue, though it may become a foreword, I don't know. Enjoy!
It is Friday, the fifth of May in the year 2000, the fifth day of the fifth month according to the Gregorian calendar. If not for the Leap Year, it would also be the 125th day of the year, or five cubed. Most of the world is looking forward to a pleasant spring weekend. This particular day is celebrated the world over for a wide variety of reasons that vary from place to place.

In the United States of America, the Mexican victory against overwhelming French opposition at the Battle of Puebla is celebrated, though it is confused with Mexico's Independence Day in the minds of many Americans. Citizens of Puebla observe the holiday, but it is little recognized elsewhere in Mexico. Other war holidays include Patriots' Victory Day in Ethiopia, signifying the end of Italian occupation in 1941; and Liberation Day in both Denmark and the Netherlands, commemorating local defeats of German forces in 1945. In politics, Kyrgyzstan celebrates the seventh anniversary of adopting their first constitution after breaking free of the former Soviet Union; the Council of Europe celebrates the fifty-first anniversary of its founding; Albanians honor those who died for their nation's freedom with Martyrs' Day; and King Bhumibol Adulyadej of Thailand looks back across half a century since his coronation, just six years shy of becoming Thailand's longest-reigning monarch. Familial celebrations are peculiarly abundant: Japan and South Korea observe Children's Day, Romania observes Men's Day, Senior Citizens' Day is observed in Palau, Indian descendants in Guyana celebrate the 1838 arrival of their ancestors to work on sugar plantations, and the ninth International Midwives' Day is observed thanks to the efforts of the International Confederation of Midwives.

The feast of Blessed Edmund Ignatius Rice is also held on this day, his beatification occurring in 1995 when Pope John Paul II officially recognized as a miracle the strange convalescence of one Kevin Ellison in 1976. Ellison, then nineteen, developed gangrene in his large intestine as a complication from an appendectomy. Five doctors agreed that Ellison's colon did not have enough healthy tissue to see him through the next two days, but after a priest gave a relic of Edmund Rice to the family to be placed by Ellison's bedside, there appeared quite a bit more healthy tissue in Ellison's colon, and he went on to a full recovery. Two competing explanations seem to offer themselves for our consideration: either five practicing doctors made an egregious error, or a dead man cured intestinal gangrene through the strategic placement of one of his Earthly knick-knacks. When confronted with the opportunity to believe in either serious magic or serious human error, the Pope chose to affirm a belief in magic. One cannot help but wonder whether such a mind places greater implicit trust in the powers of deities or doctors.

Other uncelebrated but nonetheless historic occurrences have also marked this day throughout history. In 1981, Bobby Sands died in prison, ending his 66-day hunger strike in a two-day coma. In 1961, Commander Alan Shepard became the first American in space, launched 115 miles into the sky during a fifteen-minute flight. In 1925, John Scopes was arrested for teaching the theory of evolution to public school children, the first of many legal absurdities wherein scientists would be forced to struggle against the forces of parental ignorance in order to have an overwhelming preponderance of evidence presented honestly to the next generation. And in 1955, when the fifth of May was in fact the 125th day of the year, Jonas Salk witnessed the 500,000th (that's a five followed by five zeroes) London vaccination against polio, less than one month after announcing his discovery. All those fives, while certainly prominent, are utterly meaningless, arising as they do from nothing more profound than the arbitrary counting conventions of our culture.

Such coincidences occur regularly throughout history - roll six dice enough times, and they'll eventually all come up six. To the ominously minded, omens abound, and every chance event and surprising occurrence is positively laden with tantalizing but illusory auspice. Yet a question remains: what's the difference? How can we know whether we are dealing with doctoral error or divine intervention, especially when doctors might jump at the opportunity to gloss over a mistake, and priests might seek to rekindle the faith of a dwindling congregation? What is the difference between the meaningless parade of fives from Dr. Salk's footnote of a trip, and the highly meaningful parade of laboratory experiments that led him down the road to one of the most remarkable medical breakthroughs of the twentieth century? It certainly seems that we should want some way of knowing whether Salk's findings were attributable to chance, a medical one-in-a-zillion freak occurrence; surely another one-in-a-zillion freak occurrence might be five doctors completely missing part of a person's colon when that's exactly what they were poking around for, never mind the odds that a man in the sky cured gangrene overnight because the feng shui was just thus and so. When we decide to question our answers, where does it end? And what do we risk by dwelling on these questions too long, or answering them too hastily?

Call it fate, call it chance, call it blind cause and effect, but today is an auspicious day. Given enough time, good bookkeeping, and the human desire to immortalize today in the memory of tomorrow, every day is bound to become auspicious. But this day is extraordinary, even as every person goes about his or her business in a perfectly ordinary way. Children play on playgrounds, adults procrastinate at work, teachers teach and preachers preach, while street corner doomsayers shout the words of long-dead prophets at passing motorists and pedestrians. The doomsayers are wrong in many important ways, of course: the world is not ending, Christ is not coming, the end is not nigh, and no repentance is necessary. The prophecies that so move them today have moved them and countless others like them to similarly foolish acts, and other prophecies have moved others still to yet more foolishness. Nevertheless, the fact remains that in one very important way, they are right: human civilization stands on the brink of collapse, as it has collapsed at other historical junctures.

Even for all that, you can't really give credit to the doomsayers for their inadvertent accuracy. After all, a broken clock is still correct for two glorious minutes of every day.

Sunday, August 1, 2010

101 Interesting Things, part forty-five (b): Blood - Hemoglobin and Homeostasis

"Hemoglobin is the key to a healthy heartbeat."
- Placebo, Haemoglobin

Blood - vertebrate* blood, at any rate - is red because the erythrocytes that float in plasma are red. The erythrocytes, in turn, are red because of all the hemoglobin in their cytoplasm. It's chock-full of the stuff. In the diagram below, the four green wire-frame looking bits (as opposed to the red and blue ribbon-looking bits) are the ferrous heme groups that bind up the oxygen you breathe into your lungs:
Oxygen diffuses into your red blood cells through the alveoli of the lungs, where each of those heme groups grabs an oxygen molecule. It's easy to do, since oxygen is fairly plentiful in the air we breathe. That may not seem like a whole lot, but it increases the amount of oxygen your blood can absorb by about seventy times, since otherwise oxygen could only dissolve into your plasma as a gas. Then, as your blood courses through your body, the lack of oxygen causes the iron atom in each heme group to lose its grip on the oxygen molecule it's holding, and the oxygen diffuses into nearby cells where it fuels the chemical reactions that drive you. That's... really all it is! Just pressure. Lots of chemical reactions, it turns out, are more like making soup than they are like building a machine, and the body's urgent need for oxygen in every cell means that a quick and dirty solution like this is all it takes (no fancy-pants calcium ion pumps or anything).

Of course, hemoglobin isn't the only solution to this problem. Molluscs and arthropods use cuprous hemocyanin, which does the same thing but has way cooler color-change action. See, deoxygenated blood is dark burgundy in color, whereas oxygenated blood is a more vibrant red. When hemocyanin is deoxygenated, it's colorless - but when oxygenated, it's blue. Look at this crab:
To be fair, hemocyanin bonds a little stronger to oxygen, which is what makes it so good for the invertebrates that use it, because they often inhabit oxygen-poor environments. On a related note, carbon monoxide bonds much stronger to the heme groups, rendering them useless because it never leaves, and this is why CO is such a deadly poison. Other solutions to the "Gee, I need oxygen in my blood" problem include hemerythrin, which is pink when oxygenated and colorless when deoxygenated, and the Christmas-themed chlorocruorin, which is red when oxygenated but green when deoxygenated.

OK, enough about other kinds of blood, back to your blood! After your erythrocytes have dumped their truckload of oxygen into your hungry hungry cells, they pick up the carbon dioxide to carry it to the lungs for exhalation. This is done in three ways: about 7% of your waste CO2 is dissolved directly into plasma, 23% combines with hemoglobin, and a whopping 70% is transformed by carbonic anhydrase (which is in your erythrocytes' cytoplasm) into carbonic acid. The Alert Reader who is passing familiar with chemistry will notice that carbonic acid dissolves in water by separating into a negatively charged bicarbonate ion and a positively charged hydrogen ion (or, as physicists are wont to call it, a proton). The Alert Reader who is passing familiar with chemistry will also notice that free-floating protons in water tend to result in hydronium ions, and the negative log of the hydronium ion content is what is measured when we refer to "pH". Here is a chart showing what happens when your blood pH gets outside the narrow range of 7.35-7.45 that I mentioned when we spoke last:
The Alert Reader who is passing familiar with Greek will notice that everything outside of Normal ends in "-osis", which means problem (loosely translated). So how does your body fastidiously avoid such problems? Well, in the first place, it's not like all your cells take in oxygen at once and then pass off carbon dioxide all at once. That would just be silly. But your body is always metabolizing, all the time always until you're dead, and so it needs to keep a tight rein on your blood pH as you go through your varying levels of activity.

Blood is slightly alkaline, and your bones are basically load-bearing mineral deposits, so that helps at least a little bit (Fun Fact: consuming too much animal protein in relation to vegetable protein has been implicated in bone mass loss in females!). Short term pH imbalance can be corrected by altering respiration: expelling more CO2 will increase the proportion of CO2 dissolved in blood (less carbonic acid means more alkaline blood), and holding on to more CO2 will increase the proportion held as carbonic acid (or H+ and HCO3-) and increase acidity. In the long term, your kidneys respond by excreting the leftover acid or base that builds up in your bloodstream, and also regulating the amount of buffering ammonia in your blood.

Your blood also helps regulate your body temperature through the clever application of plumbing. Heat is generated in various organs such as the liver and the brain (even thinking is exothermic!), and blood acts as a coolant to help you avoid overheating by absorbing some of the heat and bringing it to the heat sink that is your skin. In addition to sweating, your body sheds excess heat by expanding its arterial walls, increasing blood flow to the capillaries near the surface of the skin where the heat escapes into the atmosphere, or at least into your sweat (if the surrounding air temperature is higher than your body temperature). When you need to conserve heat, your arteries constrict, reducing blood flow to the skin and extremities to conserve heat and thus maintain core body temperature. This is why the cold will often make you numb and pale: your thoracic cavity needs all the heat it can hold on to, and the rest of you is somewhat more expendable. Note that this is distinct from frostbite, which results from ice crystals puncturing cellular membranes and causing cell death (this is why frostbitten tissues are kinda gelatinous when thawed, and one of the key hurdles for cryonics to overcome in the quest for legitimacy).

OK, oxygen transport, acid-base homeostasis, and thermoregulation - check! Tune in next Wednesday when I chatter on about the army of your immune system!

* - There just had to be an exception, didn't there?! The crocodile icefish does not use hemoglobin, and is the only vertebrate known not to do so. It lives in sub-zero seawater where it can absorb all the oxygen it needs right through it's goddamned skin. Fuckin' icefishes have it so stupid easy.