Friday, March 10, 2006
I remember the last time I felt the ocean. It was at Port Isabel, near Padre Island, the week after spring break. The beach had a hangover: crumpled beer cans and cigarette butts, candy wrappers and used condoms. Herring gulls squabbled over choice bits of trash and cried as they wheeled in the sky. The sun was sulking under a blanket of clouds. An unseasonably chilly wind, greasy with salt, blew fitfully across the waves.
The sea spread out to the horizon, rippling like a vast sheet of gray-green satin. The easy roll of the distant swells turned to a surge of foam at the shoreline. The whispering roar of the waves was calling me, pulling my blood as the moon pulls the tide.
I found a clear spot of sand and stripped down to my swimsuit. The wind knotted my skin with goosebumps. I left my sneakers on; the sand was full of hidden fish hooks.
I crossed the beach and waded in, shivering and wincing at the first cold bite of salt on my legs. The current tugged at my ankles. I'd been warned about the undertow; it had dragged under dozens of unwary swimmers. I imagined the victims being pulled down, down into the dark water to become a feast for deep-sea crabs. But today, the undertow was no watery mugger; it was insistent but gentle, almost playful, like a man pulling his lover behind a tree for a kiss. I splashed out into the waves until my toes could barely find the sandy bottom.
I felt a sudden thrill of fear as the swell lifted me as though I were a sliver of driftwood. This was no polite suburban swimming pool. This water was powerful. It wasn't just the force of sheer mass that I felt. Perhaps what I sensed was the kinetic energy of the rolling molecules, the innate force of the wet, heavy children of gases joined in explosive union. Perhaps what I felt came from chemical instinct, the miniature sea in my own veins faltering in the vastness of its ancient birthplace.
After a few minutes, the surges no longer frightened me. The rising, falling swell was the steady breathing of a sleeping creature. The rhythm lulled me, and I lay back in the water and let myself float.
I closed my eyes and let my mind drift. My thoughts left my body and spiraled up, up into the sky, through the misty sheets of clouds into outer space. I imagined I could see the earth spreading below me, nothing of human civilization visible. The sea wrapped the planet like a blue amoeba that had flattened itself around a grain of sand. The sea was moving, pulsing in slow, millennial currents around the globe.
I realized that the sea itself is alive, not just a soup of fish and salt and seaweed, but truly alive. All living things within it, from delicate crystalline plankton to hardy killer whales, are part of a vast, liquid body. The ocean's organisms eat and breed and die to be reabsorbed into the system, life and death locked in a perpetual embrace, just like the cells in my own body.
I had never seen myself as anything but an individual before, but now I realized that I, too, was a cell in the salty blood. And someday I would be gone, broken down into nitrogen and carbon and water, nothing of my essence left but a few genes in future generations of cells.
I felt myself drift away farther into outer space until the Earth looked like a fist-sized white and azure jewel hanging against the blackness. I turned my face toward the heat of the sun. It was swollen, shining the wrong color, pregnant with disaster.
Then it burst, a shell of flame and shock ripping out across space. The fire tore across the Earth, tearing off its living skin, shattering its rocky bones.
I thought I could hear the beautiful blue creature scream as it exploded into cosmic steam.
I woke with a start, shaking. I was so cold I couldn't feel my feet. My skin was white against the dark water. I swam back to shore, my arms and legs weak against the waves. I staggered onto the beach and found my towel and clothes. After I dried off and dressed, I jogged along the beach to coax the blood back into my chilled limbs.
I knew I couldn't go back into the water without courting hypothermia, but I didn't want to leave. So I spent the rest of the day searching for shells in the wet gray sand. The clouds broke in the late afternoon, and I hiked to the jetty to watch the sundown show of brilliant purples and delicate pinks and oranges.
After the horizon had faded to the blackest blue, the real show began. The night tide was thick with phosphorescent plankton that flashed in green alarm at any disturbance. Every crashing wave sent up a spray of ghostly fireworks. Glowing sea foam oozed like lava in the crevices of the jagged black rocks.
Finally, my eyes would hardly stay open, and I started to shiver in the night breeze. I turned away from the jetty, trudged back down the road, through the dingy trailer park to a rickety beach shack in which even the plastic had rusted. I drew a tub of hot, clear, uninteresting water, poured in perfumed bubble bath as faint compensation, and washed the sea from my skin and hair.
But it could not be washed from my mind. As I lay in my bed that night, I could still feel my body rise and fall with the waves, the sensation like phantom pain from an amputated limb.
This essay was originally published in Lady Churchill's Rosebud Wristlet.
Labels: essay, ocean, science
Friday, November 04, 2005
This is an old rhyme taught to students in many chemistry classes so that they'll remember the correct way to combine strong acid and water.
The worst laboratory accident I've ever witnessed happened when a student failed to follow this simple rule, though it was made far worse than it should have been by mistakes on the part of the school administration.
I was taking organic chemistry during the summer semester at my undergraduate college. The university administration, in its infinite wisdom, decided to cut costs that semester by doubling up the organic chemistry labs and by cutting back on air conditioning the science building.
Bear in mind that we were in West Texas. In July. It was ninety degrees outside, and there were thirty of us packed in a lab built for twenty with Bunsen burners going all the time. It must have been close to 115 degrees Fahrenheit in that lab.
So, we were wearing our safety goggles, yes. But almost everyone was wearing short-sleeved shirts, and many kids were wearing shorts.
One day, a student was at the crowded fume hood trying to mix hydrochloric acid and water. He made the mistake of pouring the water into the acid. He made a bigger mistake when, after the mixture started to spatter and smoke, he panicked and pushed the big reagent bottle away from him.
The huge bottle of hydrochloric acid fell over, sending an equally-huge splash of acid over a knot of about a dozen students nearby. A girl who was wearing shorts got acid all down the backs of her legs; she was in bandages for weeks afterward. I don't know anyone in the room who didn't find holes in their clothing from splashed acid afterward.
When things settled down, we learned an important sub-lesson: cotton protects you from acid much better than nylon or polyester. The people who were wearing cotton got holes eaten in their clothes but not their skin. The people who were wearing synthetic clothes that got soaked got burned.
Anyhow, I'm still amazed none of the injured kids sued the school. The next day, we were separated into two different labs, and the building was cooled to nearly arctic levels so that we could wear long pants and long-sleeved shirts without fear of getting heat stroke.
Labels: chemistry, science
Friday, October 28, 2005
Octopuses (along with their closest cephalopod kin, nautiluses, cuttlefish and squids) are the most dynamic members of phylum Mollusca, which also includes snails and oysters.
There are thought to be about 200 species of octopuses. The most common species is Octopus vulgaris, which is found in every ocean and gets to be about three feet long.
They come in a wide range of sizes. The smallest species is the Californian Octopus (Octopus micropyrsus) which as adults may only be a half-inch long. The largest species is the North Pacific Octopus (Octopus dofleini) which can be over 30 feet in length and well over 100 pounds in weight.
The largest confirmed octopus ever caught was 33 feet long and weighed 600 pounds. However, there are rumors of some North Pacific octopuses living in deep waters off the coast of Canada that get to truly gigantic size. According to a perhaps-apocryphal story, a fisherman once found a rotted lump of cephalopod that weighed in at close to a ton; tissue samples later identified the flesh as belonging to an octopus rather than a squid.
Anatomically, octopuses are quite interesting. Instead of a penis, male octopuses have a specialized tentacle (usually the third tentacle on their right side) that they use for sex.
These cephalopods also have three hearts. They have a heart at the end of each of their gills; these hearts pump the blood through the gills. Their third heart pumps blood through the rest of the octopus' body.
Octopus blood itself is interesting because it uses a copper-based molecule to carry oxygen instead of the more familiar iron-using hemoglobin molecules found in vertebrate animals. Because of the copper, octopus blood appears blue instead of red.
Octopus eyes are quite sophisticated, and octopuses have very good vision. However, their eyes function differently than human eyes; instead of changing the shape of their lens to focus on different object, the muscles of their eyes move the lens back and forth within the eyeball.
But even without their vision, octopuses can get around quite well due to the extreme sensitivity of the suckers in their tentacles. In laboratory tests, blindfolded octopuses could tell different objects apart as well as visually-unimpeded octopuses.
Octopuses also have the most complex brains of any invertebrates; they quickly learn new tasks by trial-and-error, and they seem to form the same short-term and long-term memories as vertebrate animals.
Octopuses: Master Escape Artists
Being such highly intelligent creatures, octopuses are master escape artists, and can be hard to keep in an aquarium if they want out. I've known a couple of people who've gotten a small octopod for their home saltwater aquarium, only to find the creature dead and dried-up on the floor after it pried off the tank lid and crawled out in the night. One acquaintance of mine found his little octopod dead of electrocution after it escaped from its tank and made the mistake of probing a socket on a nearby power strip with one of its damp tentacles.
My marine biology professor from my undergrad college once had a laboratory job where they often kept octopuses. He learned a simple technique for convincing the new octopus that, yes, it really wanted to stay put in the aquarium.
He'd put the new octopus in the tank, do some odds and ends in the lab for a few minutes, then leave the room and turn out the lights. He'd wait outside until he heard the telltale, sodden slap that mean the octopus had staged a jailbreak and had hit the floor. He'd wait one minute, then go back into the lab and put the octopus back in the tank.
He'd repeat the process, the next time waiting three minutes. And on the third time, he waited a whole five minutes before rescuing the miserable, sticky, dust-bunny-covered octopus from the lab floor, rinsing it off, and placing it back in the aquarium.
After that third time, he told me, an octopus wouldn't try to escape again. In fact, he sometimes had to work hard to get it out if it needed to be examined or transferred to a new tank so the old one could be cleaned.
Thursday, October 27, 2005
In the rush to pack for trips to the beach or to wilderness retreats, some people will forget necessities like their toothpaste or a pillow for napping in the car. Indiana University optometry professor Arthur Bradley wants to make sure people don't forget their sunglasses.
"Exposure to high levels of UV radiation can and will damage your eyes," said Bradley. "The effects can range from an annoying scratchy feeling in your eye that eventually goes away to an incurable blindness."
According to Bradley, the annoying scratchy feeling is the result of a condition called UV keratitis. This condition is caused by damage to the corneal epithelium, the first layer of cells that coat the front of the eye. Bradley said that it takes about six hours after the damage occurs before somebody starts experiencing symptoms: pain, tearing, spasms in the eyelids, and/or blurred vision.
Associate Dean of Optometry Victor Malinovsky said that while UV keratitis is fairly rare, people run the greatest risk when they are in highly-reflective environments, such as when they're boating or water skiing on a bright day.
"In most cases, the damage is very mild," Bradley said. "The symptoms will usually disappear within one or two days."
Malinovsky said that occasionally people will need medical help. "If the symptoms are bad, people should try to go to an eye care professional, either an optometrist or an ophthalmologist," Malinovsky said. "But often, people don't start getting symptoms until early evening, so they end up having to go to the emergency room."
Bradley said that UV poses the biggest danger in that it has been linked to macular degeneration and to cataracts, an opacification of the lens that will eventually lead to partial or complete blindness.
Malinovsky said that most people will develop cataracts if they live long enough, but exposure to ultraviolet light will certainly speed up the process. He added that people who live in the tropics tend to develop cataracts 10-20 years earlier than people who live in temperate regions such as the American Midwest.
Bradley said that although many people are meticulous about slathering on sunscreen before they go out in the sun, they neglect to use anything to protect their eyes. This is particularly dangerous, because while the skin can give itself some protecting though tanning, our eyes obviously don't tan and won't develop any sort of resistance to ultraviolet radiation.
"Perhaps the most dangerous situation is created when there is a thin cloud cover," Bradley said. "Because the clouds absorb more infrared radiation than UV, the sunlight feels less intense. Although the sunlight does not feel hot under the clouds, it is still irradiating you with large amounts of UV," he said.
Bradley said that because of this, many people don't think they need protection on cloudy days and end up with a bad sunburn and painful eyes.
Bradley added that although UV-blocking sunglasses are the best protection for the eyes, not all sunglasses are created equal. He said that some people mistakenly think that very dark shades provide the best protection.
"Because we cannot see UV radiation at all, no amount of visual inspection will tell you how much UV is filtered out by your sunglasses," he said.
Bradley said that people can get UV-filtering coatings put on the lenses of their regular glasses or on their contact lenses.
"The rule of thumb is simple: if in doubt, always wear UV filtering sunglasses or have UV protection incorporated into your spectacles or contact lenses," he said.
Labels: health, science
Monday, October 03, 2005
Long, long ago in a land far, far away, I happened to be a biology major taking an ecology class. And our professor, Dr. D., decided we were such a nice bunch of
slaves students that he'd take us on a Saturday field trip to help his graduate students explore the exotic mysteries of the wily armadillo.
The armadillo is widely misunderstood. Most people think it is a quiet, quaint creature; cute, even. It's not. It's a small, smelly, armored, clawed, powerful beastie with a perpetually runny nose. Armadillo snot is not cute.
D.'s scientific interest in them stems from the fact that every time a 'dillo has a litter, the four pups are all genetically identical. This seems like a silly thing for a sexually-reproducing critter to do, since the whole point of sex is to mix up the parents' genes in new ways. Had they reached the peak of Cosmic Armadilloness, and no longer needed genetic variation? Or was this a reproductive flaw that would lead to inbreeding and subsequent appearances on daytime talk shows?
Dr. D. was determined to find out.
So, we all piled into cars to caravan to the field site several miles outside town, a grad student leading the way, my car next-to-last in line and Dr. D.'s truck last. My passenger was my friend Jennie. We amused ourselves by playing Roadkill Bingo as we drove. Soon, we saw the relatively intact carcass of an armadillo.
"Whoo, that one's got all four legs in the air," Jennie joked. "Dr. D. won't be able to resist that one!"
And sure enough, D.'s truck swerved off the road and screeched to a halt in front of the hapless 'dillo. He grabbed the 'dillo, tossed it in the bed of his truck, and drove on.
When we all got to the field site, D. gathered us in a circle. He retrieved the dead 'dillo and used it to demonstrate the finer points of armadillo wrasslin'. Full nelson, half-nelson, tail grab, the works. He even managed not to get much blood on his shirt in the process.
Then, he led us to an area where some students were tagging captured 'dillos. One student was holding down a 30-pound 'dillo while the other painted numbers on its carapace with bright pink latex house paint. The 'dillo already had a tag piercing its ear and an ID bracelet locked on its foreleg. Dr. D. explained that because the 'dillos spend so much time tunneling and running though underbrush, if the grad students were lucky, one of the three tagging measures would survive to identify the animal when it was eventually re-captured.
Suddenly, the painted armadillo broke free, scrabbling away across a rocky flat.
Dr. D. sprang into action. He sprinted after the beastie, took a flying leap and tackled it on the rocks. The armadillo squealed, and the dust rose in a huge cloud as they tussled.
When the dust cleared, Dr. D. stood in a triumphant Superman pose, holding the terrified armadillo at arm's length by its tail. Dr. D. was covered in dirt, pink paint, dozens of bleeding scratches, and armadillo shit. I wondered if he'd had a tetanus shot recently. I wondered what his wife must think of him coming home like this.
Then I remembered his stories, and realized she'd seen far worse. There was the time she'd come home and found he'd recruited her good stew pot for boiling the flesh off roadkill gopher bones. There was the time he came home with 214 chiggers imbedded in his skin (he counted). And there was the skunk incident.
Suddenly, I realized that cohabitating with a field biologist must qualify as a rare and peculiar sort of fetish.
So, if you're ever in the woods, and see an armadillo with an earring and traces of pink paint, remember, it wasn't a prank by the local punks -- it was probably your friendly neighborhood zoologist.
Labels: humor, science
Monday, September 26, 2005
During my senior year of college, a friend of mine took a mammalogy class. His professor offered the students extra credit if they would help out on a weekend project: skinning, stuffing, and mounting various roadkill animals to send out to natural history museums in the state.
My friend made the mistake of accepting the extra credit offer. The following weekend, the students discovered they had to skin and stuff about two dozen skunks.
You could smell the mammalogy lab outside the life science building. It was incredible. But, fortunately for the students working in said lab, the human olfactory system will totally shut down under such overwhelming situations of stench.
The de-scentsitized students worked through the afternoon into the evening and night. Sometime after midnight, all the skunks were done. The students were hungry. Someone said, "Hey, let's go to Denny's! It'll still be open."
The Denny's was indeed open. It even had a dozen people in it ... but not for long. The moment the unwitting lab workers entered, reeking of rotting skunks, everyone in the place dropped money on their tables and fled for their cars.
I heard they gave the unlucky waitress who had to serve them a nice tip, though.
Labels: humor, science
Friday, August 26, 2005
Makeup is any substance people apply to their skin or nails for either decoration or disguise. The decoration may be subtle (such as glitter or nail polish) or fantastic (such as the kabuki-style makeup worn by members of the band Kiss). The use of makup as disguise is sometimes extreme; everyone has seen movies in which actors are made up to look like zombies, aliens, or other inhuman monsters. However, in daily life, makeup is most often used to create the illusion of an excellent complexion.
In short, most people use makeup to cover up perceived or real flaws in their skin. Got freckles? Unwanted shine? Pale eyelashes? Spotty nails? Large pores? Redness? Dark circles under your eyes? Puffiness? Spider veins? Scars? Bruises? Blackheads? Fungal infections? Makeup can smooth it all over and make your skin look (if not actually be) unblemished and healthy.
Wearing makeup is a very personal act that helps some people feel more attractive and confident. "Putting your face on" is a cherished daily ritual for some people. But it is also a highly social act.
If you are an American woman in mainstream society, many people will expect you to wear makeup, and failing to apply it as others do can have negative consequences. If a woman wears more makeup than other women in her social group, she may be deemed to be promiscuous, trashy, or stupid. In some workplaces, a woman can be scrupulously clean and dress well, but if she fails to wear makeup, her coworkers or boss may judge her to somehow be lazy or unfeminine and therefore a less worthy person. Conversely, if an American man wears noticeable makeup, people may well assume him to be homosexual.
So why wouldn't a person want to wear makeup?
There are many reasons:
1: Health Concerns
Some women have extremely resilient skin; they could slather on a foundation of 80% motor oil every morning and not get a single pimple. Other women at the opposite end of the spectrum are not so lucky. They have "problem" skin that is prone to blackheads and acne and other infections, and wearing makeup, no matter the maker's claims that their products are noncomedogenic and hypoallergenic, makes their skin worse.
So, what's in makeup that could create skin problems? Plenty:
- Formaldehyde. You may be familiar with this chemical from its use in preserving dead frogs for your high school biology class. It's still used in nail polishes as a hardener, and formaldehyde resins are used in rouges and face powders. Formaldehyde is an irritant, and it's known to cause cancer.
- Dibutyl phthalate. Banned in Europe, this chemical is widely used elsewhere as a plasticizer in nail polishes. It's also a teratogen that can also cause allergic reactions.
- Dyes such as Benzyl Violet 4B (aka Violet 2). The state of California has declared Violet 2 to be a cancer-causing agent. It's also likely to trigger skin reactions in sensitive people. Other dyes can cause similar reactions.
- Stearalkonium hectorite. This is used in a wide array of cosmetics; it may chemically change to nitrosamines while on the skin, which are known to cause cancer.
- Methylparaben. There's evidence that this common cosmetic ingredient may affect a person's hormone levels and in turn increase the risk of some cancers. It can also trigger allergies in sensitive people.
- Salicylic acid. This is added as an anti-acne ingredient to some cosmetics. However, many people with sensitive skin find that it causes irritation that can make skin more prone to breakouts. It can also increase a person's sensitivity to ultraviolet light and make them more prone to skin damage from the sun.
- Glycolic acid. This is an alpha-hydroxy acid used in many cosmetics to smooth wrinkles. It can cause irritation in sensitive people; it can also make you more prone to UV damage.
- Coal tar. This is used in some lipsticks, mascaras and eyeliners as a blackening agent. It's carcinogenic.
- Lanolin. This natural moisturizer derived from sheep's wool is touted for its mildness, but it can trigger severe allergic reactions in those sensitive to it. The less purified lanolin is, the more likely it is to cause trouble in people who react badly to wool. Other natural ingredients, particularly botanicals, can pose the same problem.
- Sunscreens like PABA, cinnamates, mexenone, and oxybenzone. These can be allergens to sensitive people, and they can also ironically make a person more sun-sensitive.
- Lead. In 2007, product tests commissioned by the Campaign for Safe Cosmetics indicated that many brands of red lipsticks contain unsafe levels of this heavy metal, which is known to cause high blood pressure and damage the brain and kidneys at toxic levels.
- Bacteria. Most cosmetics don't start out contaminated by pathogenic bacteria, but it's very easy to contaminate liquid or powdered makeup with bacteria from your fingers or from an applicator sponge after it's touched your face. Makeup that gets shared with other people is especially prone to bacterial contamination, which can cause skin and other infections.
In short, there's lots of substances in makeup that can cause irritation to sensitive skin. Irritation leads to inflammation, which makes skin prone to infection and scarring. Furthermore, a nontrivial number of ingredients in cosmetics might give you cancer in the long run. And that's not pretty.
When a woman who's struggled to find a non-irritating makeup for years discovers that her skin looks and feels better when she simply washes it with a mild glyerine soap twice a day, laziness has nothing to do with her decision to stop wearing cosmetics.
The nature of makeup itself, rather than its specific ingredients, can cause problems.
Inhaling any fine dust, such as face powder, can trigger asthma or seed a lung infection.
Many eye doctors discourage their female patients from using eye makeup such as mascara, eyeliner, and eye shadow because particles from the makeup may get in the eye and trigger allergic inflammation or infections. Furthermore, according to the FDA, accidentally scratching one's eye with a mascara wand is a fairly common injury. Damage to the eye can cause corneal ulcers or ultimately blindness.
2: Financial Concerns
Many women find that the more inexpensive a cosmetic is, the worse it looks and the more likely it is to contain irritating ingredients. Good-quality makeup gets very expensive. A woman with limited funds may well decide that no makeup is better than cheap makeup. If she's struggling to make ends meet, she may decide to spend the $30 she'd pay for a tube of Clinique on buying her child better food or on whittling down her credit card debt.
3: Personal Comfort
Some people simply don't like the feel of makeup on their skin. Contact lens wearers may find that dust and flakes from makeup get in their eyes with painful results. A regular eyelash in the eye can be uncomfortable, but cover it in mascara and it's far worse.
4: Interest in Living a Simpler Life
Your last boyfriend broke up with you because you were "too high-maintenance". Your girlfriend cattily remarked, "Maybe if some of us would forgo that 5th coat of mascara, we'd actually make it to the restaurant on time!" Your boss fired you because you're perpetually late to work.
So you decide one day to chuck all the cosmetics you spend hours a day applying and re-applying, and you never look back.
5: Social Concerns
As noted previously, mainstream American society expects certain things of women that it does not expect of men. People may subsequently refuse to wear makeup as their own personal social statements. Some might be:
- You're male, and don't want to be seen as "freaky" or "gay".
- You're female, and feel bad that men can't join in the fun and wear makeup, so you won't except in places where they can, too.
- You're female, and are annoyed by peer pressure to wear makeup to be accepted by others, so you pointedly refuse to wear it.
- You believe that the cosmetics industry has grown rich by promoting and exploiting people's vanity and personal insecurity, and you think it's hurt society.
- You think the cosmetics industry is evil for testing products on bunnies.
- You think there's too much emphasis on superficial beauty and not enough on inner beauty; you want to show others that one can be beautiful without makeup.
- You realize that much standard makeup is a stylized representation of sexual receptiveness (such as red lipstick mimicking the engorgement and flushing of lips during sexual excitement) or an effort to emulate adolescent feminity (such as eye shadow mimicking the thin, translucent eyelids of teenage girls) and you think all that is a bit creepy.
- Your religious leader has denounced makeup as a sinful tool of wanton vanity. Since you don't want to inadvertently go to Hell when you die, you skip the blush and lipstick and go barefaced.
- You think you look just fine without a bunch of stuff on your face, thankyouverymuch!
Labels: cosmetics, gender, health, science
Thursday, August 25, 2005
Valerian root (Valeriana officinalis and V. dioica, both native to the temperate parts of Europe and Asia) is widely available as an herbal supplement; while it has no FDA-approved medicinal use, it is touted as a sleep aid and anticramping agent.
Medical studies have shown that it acts as a mild sedative/hypnotic and has anti-anxiety properties. Thus, it's often recommended to people suffering from mild insomnia or restless legs syndrome, because when it's used in a sensible, dose-aware manner, it's not as "druggy" or expensive as over-the-counter or prescription sleeping pills.
Let me repeat: use this herb sensibly. Don't toss a dozen capsules down with a fifth of gin and wonder when you turn up with a killer hangover and a sick liver. Valerian is by no means a completely harmless substance; no long-term medical studies on the safety of the herb have been done in the U.S.
A friend of mine who works as a nurse says, "Don't overuse/overdose valerian root because it may cause liver damage. Also, don't take it with alcohol, antihistamines, or other central nervous system depressants -- the combination may cause serious sedation. The other thing is, I have come across people who think that just because something is 'natural' or an herb, it won't have side effects like a drug has. They do have those side effects and they are sold over the counter with no warning label. It would be like selling 1mg of Valium over-the-counter with no warning that taking 20 capsules would cause sleep of the dead. I think it's great we have access to these herbs from a consumer's perspective, but I think people need to be far more educated than they are before they ever use them."
The typical valerian dosage is 300-600 mg of the root extract in capsule form taken shortly before you go to bed. A useful dosage is hard to pin down because the quality, purity, and strength of the herb may vary widely between manufacturers. The active chemicals in valerian root seem to be valepotriates, sesquiterpenes and valeric acid.
In my opionion, valerian smells dreadful. If you take it regularly, you will be imbued with its assy stink. Some people have found that valerian upsets their stomach, gives them diarrhea, or makes them groggy.
Valerian also acts as a dream enhancer for many people. While this may be a cool thing for many folks, it's not so good if the reason you've been having insomnia is because you keep having nightmares. Chances are good that while valerian will help you get to sleep initially, it will make your nightmares much worse and you won't get much rest.
Some people also seem to develop a tolerance for valerian and it stops working for them after a while.
If valerian doesn't work for you as a sleep aid, try taking 250-300 mg of magnesium along with 300-600 mg of calcium citrate with a full glass of water an hour before you go to bed. I've had good luck with this combination so far. If you have heart rhythm issues, though, check with your doctor first because the magnesium might cause you problems. Don't be surprised if the magnesium gives you a bit of diarrhea, but the calcium should buffer you against the effect.
For more reading: http://www.aafp.org/afp/20030415/1755.html
Labels: health, science
Friday, August 12, 2005
You step into the shower, only to discover that your shampoo bottle is practically empty. Argh! You fill the bottle partway with water, shake it up, and douse your wet hair with the diluted, sudsy shampoo. In seconds, you're lathered up, rinsing off, and ready to face your day.
As you turn off the water, you realize you've still got some shampoo solution left in your bottle. You're tempted to put the bottle back in your shower caddy and save the remainder for your next shampoo. After all, it seems a waste to just dump it, and you haven't got much time to go to the store to get a new bottle.
Resist temptation, brave shampooer. If you dilute your shampoo to eke another day's hairwashing out of a bottle, throw the rest away immediately afterward.
Why? According to a chemist friend of mine, once you've diluted shampoo, you've rendered the preservatives in it too weak to do their job. Your watered-down shampoo is chock full of nitrogenous compounds and carbohydrates that bacteria and fungi will find oh so tasty. So if you let this solution sit for a day (or more) and then dump it on your hair, you'll also be dumping on a nice homemade culture of various nasties that may find your scalp to be equally delicious. You could find yourself getting a case of dermatitis or an infection.
Common Shampoo Chemicals (And What They Do)
Acids: the innate alkalinity of soaps and detergents can make hair look dull because the hair cuticle swells and gets rough in an alkaline solution, so most shampoo manufacturers add acids to brighten hair's shine. The pH of most shampoos is usually 6.5 to 7.5.
Detergents: these remove oils from your hair and let them dissolve away in water.
Lather builders: suds improve shampoo's cleaning action.
Conditioners: these chemicals put a coating on the hair shafts to make them thicker, smoother, softer, easier to comb, and less prone to static; they also strengthen the hair's cuticle.
Thickeners: these add body to the shampoo and some also act as weak conditioners.
Preservatives: these keep down bacterial and fungal growth.
Sunscreens: ultraviolet radiation can damage your hair and scalp.
* Some thickeners and conditioners cloud shampoo and, in the absence of dyes to make the shampoo green or blue, also tend to make it look very much like semen. Additives like oils and proteins that have not been thoroughly emulsified will also cause this effect.
References: http://www.exploratorium.edu/exploring/hair/hair_3.html, http://www.chemistrystore.com/shampoo_formulas.htm
Labels: cosmetics, health, home tips, science
Wednesday, August 10, 2005
(From Greek: adelphos=brother + phagos=eating)
Adelphophagy, which literally means "eating one's brother", refers to the act of pre-birth cannibalism. In other words, it's the killing and devouring of broodmates while the cannibal and victim(s) are still in their mother's womb.
Talk about your sibling rivalry.
This type of cannibalism, which is also known as "embryophagy", is common in many species of deep sea sharks that give birth to live young (see below). It was first discovered in 1948 when a marine biologist who was poking about in the uterus of a pregnant sand tiger shark got a nasty vagina dentata surprise: one of the unborn sharks chomped his hand.
Adelphophagy has also been seen in other fish, and it's suspected in coelacanths (Latimeria chalumnae).
Other aquatic and marine species engage in a less-gruesome form of adelphophagy: oophagy. These fetal organisms eat unfertilized eggs that their mother releases into her womb to supplement the nutrition they get from their yolk sacs. Scientists first documented oophagy in mackerel sharks in 1907. Since then, it's been identified in a wide range organisms: mollusks, crustaceans, echinoderms, polychaete worms, and kynorynchs.
Evolutionarily, any form of adelphophagy is about producing bigger and stronger offspring that are ready to compete in a brutal world the moment they're born.
Known Adelphophagic Shark Species
- basking shark (Cetorhinus maximus)
- false catshark (Pseudotriakis microdon)
- crocodile shark (Pseudocarcharias kamoharai)
- longfin mako (Isurus paucus)
- shortfin mako (Isurus oxyrinchus)
- tawny nurse shark (Nebrius ferrigineus)
- porbeagle (mackerel shark)(Lamna nasus)
- salmon shark (Lamna ditropis)
- sand tiger shark (Carcharias taurus or Eugomphodus taurus)
- slender smoothhound shark (Gollum attenuatus)
- bigeye thresher shark (Alopias suprciliosus)
- common thresher shark (Alopias vulpinus)
- pelagic thresher shark (Alopias pelagicus)
- white shark (Carcharodon carcharias)
Friday, July 01, 2005
Everybody knows that the Earth has a moon: Luna* is roughly a quarter of the size of our planet and is second only to the Sun in celestial brightness. In fact, it is so big relative to our planet's size that it almost qualifies in some scientists' books as a double planet. Luna orbits 384,400 km from Earth, has a diameter of 3476 km, and masses 7.3522 kg. The Moon was also called Selene and Artemis by the ancient Greeks.
However, fewer people know that an asteroid discovered in 1986 is locked in a complex but stable orbit around Earth, making it technically a second moon. The asteroid was named Cruithne (pronounced croo-EEN-ya) and has a a 1::1 resonance with Earth. It takes a year to go around the sun. It is co-orbital with the Earth (meaning it shares the Earth's orbit), but more importantly, it co-rotates with the Earth. This gives it what is known as a "horseshoe" orbit; as the Earth moves, the satellite travels around the Earth, then turns and travels back as if it were following the edges of a gigantic circular horseshoe hovering around the planet. Previous to Cruithne's discovery, such orbits were only theoretical. Cruithne was named after the first Celtic tribe to populate the British Isles -- this tribe is more commonly known as the Picts.
In September of 2002, an amateur Arizona astronomer named Bill Yeung discovered an object in a 50-day orbit around our planet that was briefly thought to be a third moon. Soon after giving the object the designation J002E2, astronomers at the Minor Planet Center in Massachusetts discovered it is actually Apollo 12's cast-off 3rd stage booster. The search for a third natural satellite continues.
Many people had theorized, seriously or fancifully, the existence of a second moon long before before Cruithne was discovered.
In 1846, French astronomer Frederic Petit, then-director of the observatory at Toulouse, claimed to have discovered a second moon in an elliptical orbit around the Earth. While the claim was mainly ignored by his peers, writer Jules Verne learned of it and became intrigued by the idea; he mentions Petit's postulated second moon in his 1865 novel From the Earth to the Moon.
After the publication of that novel, amateur astronomers all over the world rushed to be the first to discover a second moon. In 1898, Dr. Georg Waltemath, a Hamburg scientist, really upped the ante. He announced he'd discovered a second moon inside a whole system of tiny moons orbiting the Earth. In 1926, an amateur German astronomer named W. Spill also claimed to have found a second moon. All such claims, of course, were disproven.
Astrologers particularly latched onto the idea of a second moon. In 1918, an astrologer who called himself Sepharial (his real name was Walter Gornold) declared the existence of a second moon and named it Lilith, after Adam's demonic wife before Eve. According to this astrologer, Lilith was invisible most of the time and only became apparent when it crossed the sun. Lilith, though bogus, captured lots of people's imaginations as bright Luna's black twin representing man's darker nature. It became incorporated into some horoscopes as a result and some astrologers may mention it even today.
Several other authors have since postulated the existence of a second moon. For instance, Samuel Delaney's 1975 novel Dhalgren features an Earth that mysteriously acquires a second moon.
Eleanor Cameron did a more memorable moon treatment in the early 1950s. She wrote a series of children's novels (The Wonderful Flight to the Mushroom Planet and Stowaway to the Mushroom Planet) that are about a tiny, habitable second moon in an invisible orbit 50,000 miles from Earth. The "Mushroom Planet" is covered in various types of mushrooms and is populated by little green people. The premise of course has no scientific credibility, but as a child I found these books delightful.
* Yes, as others have helpfully pointed out, scientists call the moon just "The Moon"; however, all things moonlike are referred to as being lunar, so Luna is still being used as a scientific moniker in some regards. I'm employing the Roman name here to distinguish our major moon from other, lesser or imaginary, moons.
Labels: science, science fiction
Thursday, June 30, 2005
When your skin is exposed to ultraviolet light, it sustains DNA damage. Just a few seconds of exposure to sunlight can cause subtle damage. Fortunately, genetically-normal people have an enzyme (an abzyme ) in their bodies whose sole purpose is to repair these tiny everyday cellular insults by adding the proper base pairs back into your broken DNA. The unfortunate folks who have xeroderma pigmentosum lack this enzyme, and as a result they must avoid sunlight entirely.
However, if you sustain a severe, blistering sunburn, there is so much damage that the repair enzyme starts to randomly insert base pairs to stitch the DNA strands back together. Thus, it's almost guaranteed that mutations will be introduced. People lose skin cells all the time, so most of these mutated cells will just die and be sloughed off ... but longer-lived cells in the dermis may turn cancerous. This is why just a few blistering burns in your childhood can substantially increase your chances of getting skin cancer as an adult.
Wearing sunscreen can help (usually, see below), but it's never as good as clothing and hats that block sunlight entirely. If you are very fair-skinned you may not even have to get a proper burn before you start feeling the ill effects of excessive sunlight exposure.
There are three types of ultraviolet radiation: UVA, UVB, and UVC. UVB radiation is the kind that causes your skin to visibly burn, but the other types are quite capable of causing DNA damage. Most sunblocks nowadays include chemicals that screen out both UVA and UVB, but the amount (and effectiveness) of the UVA-blocking chemicals can vary widely. We rely on the ozone layer to block UVC.
I have very pale skin, and for the past three years I've been mainly nocturnal. When I went to California recently, I knew full well that I was likely to burn, so I mostly wore long sleeves (preferable given the chilly San Francisco climate), wore a hat most days, and religiously slathered on SPF 30 sunblock every morning.
I got only a very mild burn on my nose and cheeks, but by the end of the week I had a case of sun poisoning. Most of my sun-exposed, sunblock-slathered skin looked absolutely normal and had no trace of tan or redness. But it felt hot and tight, and I was having fever and chills. There was little I could think to do but take Advil for the fever and drink lots of liquids (later I found out the Advil would have done me more harm than good, but by that time I was mostly indoors).
I suspect that my illness was caused by my body's reaction to the UVA I'd absorbed over the week that my sunscreen didn't properly block.
It's also possible I was betrayed by my sunscreen. After returning from the trip, I found out that, ironically, sunscreens and lotions that contain bergamot oil, sandalwood oil, benzophenones, PABA, cinnamates, salicylates, anthranilates, PSBA, mexenone, and oxybenzone can cause photosensitivity reactions in some people and make them more likely to burn. Guess what the active ingredient in my sunscreen was? Oxybenzone.
I'm glad I wasn't on any medications, as there are many types of drugs and preparations that can cause increased sensitivity to ultraviolet light:
If you are taking any of the above medications, you should should be doubly careful when you go out in the sun, because research indicates that their photosensitivity effects are triggered by UVA radiation.
Labels: health, science
Tuesday, June 21, 2005
If a person eats or drinks radium-tainted materials, about 80% of the radium will be excreted fairly quickly. The remaining 20% will be absorbed into the bloodstream and carried throughout the body.
Because radium is chemically similar to calcium, the body will mistakenly use it in various biochemical pathways that require calcium. In particular, the body will try to incorporate radium into bones and teeth.
Thus, smaller, chronic doses of radium have been strongly associated with cancer, particularly bone cancer. Larger doses can result in much more immediately serious disease.
An illness termed "radium jaw" (similar to "phossy jaw") was first seen in the mid-1920 amongst young women who worked in clock-dial painting factories that used radium to create the luminous paint. These women had the habit of licking their brushes to make the bristles form a point. As a result of their radium exposure, they were suffering horrible illness: their jawbones were disintegrating, their teeth were fracturing and falling out, and they were suffering from awful mouth and gum infections and ulcers.
A forensic pathologist named Harrison Martland discovered the radium paint was the culprit in 1925 after he tested the women and found that their breath carried radon gas (which is created from radium decay) and that their bodies were giving off faint gamma radiation.
Many of the radium-poisoned women died young, often from massive infections caused as a side effect of their immune systems having been severely impaired. Their bone marrow -- and thus their ability to make white blood cells -- had been destroyed by the radiation. These women didn't live nearly long enough to get cancer. Autopsies on the women showed that their spleens and livers were giving off alpha radiation and their bones were so radioactive that they would make an image if they were laid on photographic paper in a darkroom.
Most people are exposed to radium as a result of occupational exposures from working with radioactive materials, generally by breathing in tainted dust or vapors. Uranium miners are especially vulnerable. Radium itself is not thought to be readily absorbed through the skin, but the gamma radiation it gives off makes working near it unsafe.
If a person believes he or she has radium poisoning, they can get their urine tested for telltale radioactivity or have their breath tested for radon. Radium in the bloodstream may be removed with a chelating agent; however, once it's gotten into bones and teeth, the main medical treatment is supportive care for symptoms.
Small amounts of radium are found in coal, so people who live in coal-burning areas will be exposed to more of the radionuclide than people in other areas.
Also, radium occurs naturally in some soils and water. The EPA sets the acceptable limit for drinking water exposure at 5 picocuries per liter and 5 picocuries per gram of soil in the first 15 centimeters of soil and 15 picocuries per gram in deeper soil. Some naturally-tainted aquifers such as the Hickory Aquifer in West Texas may have many times the limit, though most water supplies have less than 1 picocurie per liter.
- San Angelo Standard Times articles (various)
Labels: health, science
Thursday, May 26, 2005
Evidently, there's quite a lot you can learn about a cow's health by sticking your hand up her butt.
More specifically, the cow's rectum is positioned so that you can feel her reproductive tract -- ovaries, uterus, and often the cervix. It's useful for doing pregnancy exams, diagnosing ovarian cysts and uterine infections, and performing artificial insemination. If you want to know more, visit Bovine Rectal Palpation.
The wall of a cow rectum is tough, flexible, and hard to tear -- but that doesn't mean ol' Bessie's going to be very pleased about having someone who doesn't know what he's doing sticking his hand up her rear. And every year, scores of veterinary students have to learn their way around a cow's backside.
I almost saw a practice session in the parking lot of my undergraduate college, which has a large agriculture department. I was walking to the biology building early one morning when I saw a cowboy leading a spotted Holstein on a leash toward a cluster of students. I wondered why the heck they had a cow in the parking lot ... until I saw the shoulder-length rubber glove the cowboy wore.
I hurried on, silently wishing that the ag students had access to some kind of model they could use in the privacy of their own laboratory instead of a very public cow-poking demonstration.
A University of Glasgow researcher named Sarah Baillie has made just such a model, citing an increase in students and a lack of test cows.
The simulator is housed in a life-size fiberglass model of the back half of a cow. The student inserts his or her hand in an appropriately-placed orifice, and sensors pick up the student's hand position and generate a 3D model of it on a nearby computer so that the instructor can critique the student's handwork.
To improve the realism of the experience, the cow model is equipped with a haptic force-feedback device called PHANToM, which is produced by SensAble Technologies.
If you want to see pictures of the bovine rectal palpation simulator in action, visit The Haptic Cow Project.
The same research group is working on a model for horses.
Wednesday, May 11, 2005
Your Uncle Oscar speaks in grunts and always smells of spoiled herring. Your cousin Nellie never stops smiling and reads nothing but religious tracts. Your 80-year-old paternal grandfather has an eyepatch, leers at your mother, and keeps the mummified hand of an SS officer in a trunk in the attic.
For years, you prayed you were adopted.
You couldn't really share blood with this mixed bag of loonies and creeps your parents insisted was your family ... could you?
Years later, at a family reunion, you finally met your third cousin twice-removed Valerie from California. You hit it off almost immediately. She had a smile like a sunrise, and she was everything the rest of your family was not. In short, she was hot.
That night, you couldn't purge the impure Valerie-thoughts from your mind, hard as you tried. She's your cousin for pity's sake ... if the two of you had kids, they'd be sure to have 14 fingers or two heads or an extra eye or something.
Or would they?
Unzip those genes and show us what you got, Baybee
People have argued Nature vs. Nurture since Crick annd Watson figured out that DNA is responsible for our heredity. Your genes are the recipe for you. The food you eat and the environment you grow up in can improve or wreck that genetic recipe, much as using unripe cherries and moldy flour would wreck a prize-winning pie recipie, but using fine shortenings and flour and just a little extra sugar can make an ordinary cake sublime.
A baby with a pro NFL player's genes isn't going to be any kind of athlete at all if he or she gets exposed to thalidomide in the womb at just the wrong time. If you separate two identical twins at birth, and send one to live with a kindly adoptive family in Marin County, CA and the other to an angry alcoholic foster mother in Stripmine, WV and check back in 30 years, you'll probably find that the California twin tests as having a notably higher IQ than the West Virginia twin. But at the same time, you'll probably find that the pair have truly eerie similarities when it comes to personal likes and dislikes.
Nurture counts for a lot, and being in the same family with someone often means you've gotten the same kind of nurture (or lack thereof). But the genes are always a powerful factor in who we are; one gene can mean the difference between having blue eyes or brown, getting cancer or not.
And many evolutionary biologists such as Richard Dawkins (author of The Selfish Gene) think our genes are the root of why we care for family more than our neighbors, and care for our neighbors more than random strangers. The Game of Life is all about getting your genes into future generations, and so you have some stake in ensuring the welfare of those who share your genes: your immediate family, or failing that, your tribe.
Tell me about your mother ....
When a person makes eggs or sperm, half his or her genes get parceled out in fairly random fashion into each gamete. And every child gets half his genes from his mom, and half from his dad.
So, you share 50% of your genes with each of your parents, right?
Well, probably. It depends on whether or not your parents have genes in common; if they're from the same ethnic group (for instance, if they're both blonde, blue-eyed Swedes), they almost certainly have some DNA in common (aside from the DNA that all human beings share as a matter of course1). If a tribe of people settles in an isolated valley, after a few generations everyone in that tribe is going to be related to everyone else, even if everyone's careful not to accidentally marry a first cousin or uncle; many ethnic groups developed in this kind of genetic environment. If your parents have some genetic relation to each other, then you could have more than half your genes in common with one or both of your parents.
But, for the purposes of this article, we'll go with the 50% figure.
Now, let's talk about your brothers and sisters. Full brothers and sisters share the same parents, and because of the random dispensing of genes, it's generally thought that siblings share about 50% of their genes with each other.
Things, of course, aren't that simple.
If your mom is unusually homozygous -- in other words, she got mostly the same genes from both your grandparents due to accident or inbreeding -- then she will be passing out pretty much the same genetic set to you and your siblings. So no matter how varied your father's genes are, in that case you and your sibs would have somewhat more than half your genes in common.
If both your parents are largely homozygous, then you and your sibs would have lots of genes in common, even if your parents are from very different ethnic groups. Picture a scenario where a petite, buxom lass from a long-isolated village in Ireland meets and marries a tall thin man from a long-isolated village in Nigeria; you'd have two very different people who'd have kids who all looked a whole lot like each other.
Conversely, it's possible through the magic of random assortment for two siblings to get different genetic halves from each parent. It's rare, but it can happen; in such a case you'd share relatively few genes with your brother and sister. Got a brother or sister you seemingly have nothing in common with? Don't blame the postman; it could just be one of those things.3
And if you have a half-brother or half-sister whose father shares genes with your biological father, the two of you will have more in common than most half-sibs.
If you're half of a pair of fraternal twins, it's possible (though unlikely) to have different fathers; however, you two would likely resemble each other more than other half-brothers or half-sisters because you shared the highly-influental prenatal environment.
And to complicate matters further, there's always the chance of mutation to give you genes that none of your relatives have.
I Lost My Number ... Can I Have Yours Instead?
With the previous caveats in mind, here's the breakdown of the percentage of specific gene variants you probably share with various relatives (as opposed to genes you might share with any random stranger of your ethnic type on the street) (with possible deviance in parenthesis):
- Great-grandparent: 12.5% (possibly a bit more, possibly a lot less)
- Grandparent: 25% (possibly more, possibly less)
- Parent: 50% (possibly more if your parents share genes, but not less ... unless you're a mutant)
- Identical Twin: 100% (but maybe less if one of you mutated after your embryos split apart in the womb)
- Fraternal Twin/Full Sibling: 50% (possibly more, possibly less)
- Half-Sibling: 25% (up to 50% or so, possibly less)
- Aunt/Uncle: 25% (maybe a bit more, maybe less)
- Niece/Nephew: 25% (maybe a bit more, maybe a lot less)
- First Cousin (child of your aunt/uncle): 12.5% (maybe a bit more, maybe a lot less)
- First Cousin Once Removed (your first cousin's kid)2: 6.25% (maybe a bit more, maybe a lot less)
As you can see, unless your ancestors have significantly shared genes (and provided your more recent relatives haven't been going nutty with cousin marriages), once you're at the level of second and third cousins there's not much blood relation there at all. (Scroll down for a chart explaining cousin relationships)
So, if your grandfather really freaks you out, you can sleep safe in the knowledge that you really might not share many of his specific genes at all. Unless he's your father's father and you're a guy; then you're definitely stuck with his Y chromosome. Alas.
But Wait! There's More: The Seven Brides For Seven Brothers Family Effect
So what happens when the girls of the Walters family marry the boys of the Ruiz family? Obviously, this results in cousins who are far more related to each other than usual, and inbreeding isn't a factor.
In such a case, first cousins would share 25% or even more of their genes, though aunts and uncles would still be only 25% related to nieces and nephews and vice versa (however, the immediate in-laws would also all be blood relatives to the nieces and nephews). First cousins in this family would would share a genetic similarity much closer to that of brothers or sisters. Second cousins would be more like first cousins genetically, and so on down the line.
1: Genetic disclaimer
: all human beings share the same genome. You've probably heard the figure that chimpanzees share 98% of the genes humans have, right? That's at the genome level. This article is talking about gene variants and simplifies a good number of things; large texts have been written on human genetics and this article should not replace the information gained from said textbooks, nor is it intended as a replacement for advice from professional genetics counselors. If there are genetic diseases in your family history, and if there's no reliable test for them, having kids with anyone you think you're even slightly related to is a bad idea. If illnesses like Tay-Sachs disease or sickle cell anemia run in the family, you should probably get genetic testing if possible no matter who you marry if there's any chance you'd have children.
2: On Cousin Relationships
: I earlier had this level of relatedness listed as second cousins; my error, since my first cousins once removed had always been presented to me by my mother as second cousins, and I've never had much extended family to keep track of. Below is a handy chart I grabbed from Wikipedia
, with slight text alteration. The original colors remain, presumably for contrast; I don't think this was intended as a "green means go!" type thing. Marrying first cousins is illegal in about half of all U.S. states (see this page
for a state-by-state list), and is socially discouraged in most others.
However, some scientists argue that first cousin marriages are perfectly okay; see "First cousins face lower risk of having children with genetic conditions than is widely perceived
" from the University of Washington for details. And it turns out that third and fourth cousins who marry (remember Valerie?) may be more fertile than unrelated couples; see ""Why cousin lookin' fertile....?"
for more. (Although increased fertility is generally equated with good health and a good match, whether or not taking advantage of it is actually a good thing in the grand scheme of things -- given how badly the booming human population is stressing the environment and natural resources -- is a matter of debate).
Anyhow, here's the cousin relations chart:
3: On Sibling Resemblance:
This is supposing your brother or sister doesn't have physical traits -- like a drastically different skin color -- that don't match those of your parents and which can't be the result of a recessive gene or a mutation or birth defect etc. Bear in mind that traits like red hair, curly hair, and blue/green eyes can skip generations. Kids sometimes don't resemble their biological parents at certain ages, which is part of why paternity testing is such a big business.
Monday, April 18, 2005
It all started innocently enough. I had just begun my senior year as a biology major at a West Texas college, and I had just completed a research project on the germination requirements of poppy mallow seeds. The research had been hard, yes, and often sheer drudgery, definitely, but in the end, it had been fun.
Yes, between the seed-collecting field trips in which my blistering skin threatened to turn me into a melanoma farm before my 30th birthday and the hours upon hours of blindingly dull lab work staring through a microscope at itty-bitty plant embryos, in a sick, masochistic way, I'd actually had fun. After all, the field trips were kind of cool, in a rattlesnake-ridden way, and the little seeds were kinda pretty, especially in comparison with the fungus cultures that somebody in the lab was growing on piles of horse poop.
So, a few days before the semester began, poor doomed fool that I was, I wandered blithely into my supervising professor's office and said, "Hey, Dr. Amos, I was thinking ... I have a pretty light course load this semester, so do you think I could maybe do another research project before I graduate?"
"Why, yes." She smiled in a way that seems more and more sinister each time I remember it. "I have a project you could do. Why don't you run a series of electrophoretic protein analyses comparing your white and purple populations of Callirhoe involucrata? Some people have suggested the two are really subspecies instead of varieties. And besides, all the big schools are using electrophoresis these days. You want to be ready for graduate school, don't you?"
Of course I did. So I went out with my ice cooler and little plastic bags in which I would place one leaf from 30 different plants in each population. I drove 15 miles outside the city limits to a bucolic roadside site where one wildflower population was supposed to be and ... discovered that the highway department, in a rare fit of productivity, had graded the shoulder. Where the plants had once been was now nothing but smooth caliche and gravel.
I should have taken this as a cosmic sign that my new project was doomed from the start. But I didn't. I persevered, found other sites, collected my leaves, and took them back to the university.
Once I was back in the lab, Denise, one of the graduate students, showed me how to electrophorese with all the grace and skill of a fighter pilot showing the village idiot how to fly.
"It's really easy, once you get the hang of it. It's just like cooking," she told me brightly.
She neglected to tell me that she'd taken all her cooking classes at the Mafia Poisoning and Assassination College.
First, she showed me how to grind up the leaves. She put a little bit of leaf in the bottom of a pestle that was nestled in a tray of crushed ice, added some sand, then poured in a milliliter of an evil elixir that contained 2-mercaptoethanol. 2-mercaptoethanol, which helps break down the plant tissue into its constituent proteins, is a chemical that is a close cousin to the aromatic that gives skunk spray its odor, and 2-merc definitely shows the relationship. Unfortunately, 2-merc is also, and in itty-bitty quantities, a liver poison, a nerve poison, and a potent carcinogen. A single drop, carelessly spilled on one's skin, will be absorbed by the epidermis like an alcoholic imbibing a can of furniture polish. Even looking at a bottle of 2-merc probably causes as much bad luck as breaking a mirror with a black cat on Friday the 13th.
Holding her breath, Denise took a mortar and ground everything up into a green, gelatinous goo. The goo was put into a tiny vial and put into the deep freeze for later use. She then left me to spend the next eight hours grinding up the rest of the leaves, during which I had an allergic skin reaction to the powder in my rubber gloves that left me with Dermatitis of the Gods.
The next day, she showed me how to make the starch gel. This gel would serve as the medium through which the various denatured proteins would travel once an electric current is applied to the gel. Small proteins can travel easily between the sticky starch particles, but large proteins get bogged down, so the proteins will separate out according to size.
Making the starch gel was, in fact, very much like making slightly toxic Jell-o. She mixed a quarter-cup of powdered potato starch with a chemical solution in a big Erlenmeyer flask and had me boil it over an open Bunsen burner flame. The lab's emergency shower came in handy when I caught my barbecue mitts on fire.
Once the starch was boiling in big, sticky blops, she stuck a vacuum hose over the top to suck out all the dissolved gases so bubbles wouldn't form in the gel when it cooled. Then she poured the starch out into a little plexiglass tray and popped it in the glass-fronted fridge in the corner to cool.
Once the gel had set to an opaque white, she took out the vials of green goo and showed me how to cut wicks from filter paper while they thawed. Then we got out the gel and cut a one-inch strip near one end. We soaked a wick in each vial, then stuck the wicks between the strip and the rest of the gel at even intervals. Then the gel tray went into one of the electrophoresis pans that resided in the refrigerator. Denise put a plastic sack full of ice on the gel so that it wouldn't heat up and burst into flames during the night. Yes, Virginia, Jello will burn, especially if it has 250 volts running through it for twelve hours. We hooked the electrophoresis tray up to its power source, turned on the juice, and left.
The next day, Denise showed me how to make the dyes to stain the proteins. This process was my second cosmic warning: every other bottle had a skull-and-crossbones on it. I found out I was going to become close friends with arsenic and cyanide. I was not a happy camper.
She showed me how to cut the gel into thin slices with the aid of high-G piano wire strung on a hacksaw blade. Then she bathed each slice in a separate dye and left the slice & dye trays in a dark cupboard. After the slices had time to soak up the dye, she took the slices out and preserved them in a fixing solution that was mostly made of methanol and acetone, more liquids that don't do a body good. She showed me how to wrap and store the preserved slices so that the protein patterns could be analyzed and compared.
And then she left me to do the other 29 gels all by myself.
It was ...
a disaster of Biblical proportions
a very useful learning experience. I'm
scarred for life
pleased I went through it.
Wednesday, April 13, 2005
Whoever designed the zoology lab hadn't had aesthetics in mind. The lab tables, big black rectangles of stone on plain wooden cabinets, are gracelessly utilitarian. The sinks between the tables are stained gray from the hard water and lab chemicals. The drains stink from the residue of all creatures, great and small and dead.
I sit down on the hard wooden stool at my table and wait for the professor to arrive. The only color in the room comes from the anatomy charts on the walls and from the plastic models in the glass cases along the walls. Mounted skeletons of small animals sit atop the cabinets.
I spot the skeleton of a small dog wired to a plank, its tail up and jaws open as if it is barking at something. I think it might have been a terrier, and I think of the little terrier/chihuahua mix my mother had when I was a child. She would take him with us when we went to the grocery store because he liked car rides.
She always made me wait in the car with the dog. "Scruffy's small, and somebody might steal him and sell him to a lab," she'd say. Since then, I've found out that Scruffy, who had bad knees and worse eyes, was in little danger of dognapping. Beagles are the preferred laboratory dog because they have roughly the same lung capacity as humans and are usually easy to handle.
The professor and his graduate assistant come in lugging big white plastic buckets. I think of the huge lard buckets that warehouse groceries sell. The professor pries open one bucket with a screwdriver and reminds us that today is the dogfish dissection day.
I have never liked dissections in general, but the dogfish sounds better than some of the alternatives. The anatomy students next door are dissecting cats.
I saw the specimens out in the hall yesterday. The cats were rowed like sardines inside huge transparent plastic bags. I noticed one, a skinny mackerel tabby whose fur pattern reminded me of my cat Uno.
I stood there for a moment, looking at the tabby's chemical-clouded eyes and matted, slimy fur and couldn't help but wonder where it had come from. Had it been a stray, rescued from a slow death of disease and starvation by a quick death at the hands of Carolina Biological? Or had it been a child's pet that had wandered away and been trapped by Animal Control?
I stared at the pitiful corpses in the bags, remembering Uno patting my leg with his paw, green eyes bright, mewing softly as he begged for a dish of milk. I remembered him curled up in my lap, his fur smelling of dust and leaves, his purr loud and warm. I had to turn away and hurry to the ladies' room when I realized I was going to cry and embarrass myself.
The professor tells us to bring our dissecting trays up to the front table so that we can get a dogfish. I get my battered aluminum tray out of a drawer and stand in line. The tray is just like a small baking pan, except that the bottom is lined with black wax so that pins will stick.
The professor pulls a dogfish out of the bucket with a pair of barbecue tongs and lays it across my tray. The ugly little shark's snout and the tip of its tail stick out over the ends of the tray. The shark is a uniform, unnatural gray and it stinks of plastic.
The professor told us earlier that the school is no longer purchasing formalin-preserved specimens because formaldehyde is a carcinogen. I don't know what this new preservative is, but it is a welcome change. The dead fish smell of formaldehyde always nauseated me more than the actual dissection.
I take the dogfish back to the table and get out my lab manual and dissecting kit. I stare down at the shark, briefly imagining it swimming through seaweed in a warm ocean, a cold-blooded predator, yes, but still alive and therefore beautiful. I think that this is the irony of the laboratory; I am studying to become a biologist because I love living creatures, so I end up spending most of my time with the dead and dismembered.
I pull out my scalpel and a probe. The lab manual says I'm supposed to cut open the belly and locate the spiral valve of the stomach. Sharks do not inspire the same feelings in me as cats, but still, I hesitate, feeling uncomfortable. I know that I am a sentimental, squeamish fool; millions of creatures die every day in ways that are much less pleasant than ending up as a dissection specimen. Violent death is a rule of nature.
But in the back of my mind, I know that if I ever visited a slaughterhouse to watch the men kill steers and hogs, I would never touch meat again. And since I love T-bone steaks and hamburgers, I will never go.
I roll the dogfish onto its back. It is as stiff as if it really was made of plastic, and the plastic smell makes my eyes water. Its color is so unlike a living thing that I can believe that it is not real, that it is just another plastic model made by Carolina Biological.
The shark is a doll, a plastic doll. That's what I keep telling myself as I cut into the gray flesh.
Saturday, June 28, 2003
Sulforaphane is a plant-derived chemical that is found in cruciferous vegetables such as broccoli, Brussels sprouts, cabbage, and cauliflower (all members of the genus Brassica). More specifically, it is a sulfur-containing isothiocyanate derivative and is of great interest to medical researchers.
About a quarter of the human population can taste this chemical; for these genetically-endowed "supertasters", it is bitter, sometimes quite unpleasantly so. This accounts for broccoli and Brussels sprouts being unpopular vegetables with young children and former U.S. presidents alike.
Sulphoraphane has been extensively studied since its discovery in 1992 because it has potent anticancer, antioxidant, and antibacterial activity.
Researchers have known for years that, when the chemical is absorbed into the bloodstream, it stimulates detoxifying Phase 2 enzymes that mop up carcinogenic molecules in the body before they cause DNA damage. Other studies indicated that the chemical may stop the growth of and stimulate the death of cancer cells (apoptosis). Many researchers believe that this chemical (and the aforementioned vegetables that contain it) can provide at least some protection against a variety of common cancers, such as breast, lung, prostate, and colon tumors.
Recent research done at Johns Hopkins indicates that sulforaphane may be especially useful for preventing stomach cancer. Laboratory tests show that the chemical kills off most strains of the bacteria Helicobacter pylori; it even killed off bacteria that were hiding in cells. These bacteria cause stomach inflammation and ulcers, and are thought to be responsible for many cases of stomach cancer around the world. Furthermore, mice that were dosed with sulforaphane developed many fewer stomach tumors than did control mice after they were all poisoned with a powerful stomach-specific carcinogen (benzo[a]pyrene).
Broccoli sprouts are particularly rich in this chemical; they contain up to 50 times the amount mature broccoli plants contain.
Some health-food manufacturers have started selling sulforaphane-rich supplements; scientists do not yet know how much of the chemical a person needs to consume to gain a beneficial effect. Furthermore, since the chemical is not fully understood, the long-term effects of consuming it are unknown. However, so far the only bad side effect that has apparently surfaced is its taste.
- Science News June 1, 2002.
Labels: food, science
Thursday, June 19, 2003
The zebrafish (Danio rerio) is a species of small freshwater fish in the family Cyprinidae. Also commonly known as the "zebra danio" or "striped danio", it is widely used as a model organism for the study of vertebrate developmental biology, toxicology, and genetics. The adult fish and the developing fish embryos and larvae are all studied by scientists. This species may also be referred to as Brachydanio rerio in older scientific literature (they were first described by a British researcher named Francis Hamilton in 1822).
These pretty fish are native mainly to the Ganges River and the Coromandel Coast of India. However, they've also been found in Pakistan, Nepal, and Bangladesh. In the wild, they are usually found in clear, fast-running streams, though they have also been taken from flooded rice fields. Adult zebrafish are one to two inches long and appear silvery or silvery-yellow with four dark horizontal stripes running the length of their bodies. In India, common names for them include "lauputi" and "anju". Many people keep them as aquarium pets, and they can be bought in most tropical fish stores around the world.
They have become extremely popular research subjects over the past 30 years because they mature and reproduce rapidly and are relatively easy to care for. Zebrafish are genetically and developmentally closer to human beings than other research animals such as fruit flies and nematode worms, and they're much less expensive to obtain and care for than mice and rats. Furthermore, their genomes (they have about as many genes as human beings) have proven to be very easy to manipulate and mutate.
Many labs keep the little fish in bookshelf-like racks of shallow plastic aquaria. They can thrive in water temperatures of 22-30° C (71.6-86.0° F), although they do best in water that is about 28.5° C (83.3° F). The fish don't do well in noisy environments, and sudden loud noises stress them out. Tanks should be fitted with aerators to give the water at least 6 parts per million of oxygen. Live brine shrimp, trout pellets, and Tetra fish food flakes are the mainstays of their diet.
To get the fish to breed properly, they need a circadian light cycle of 14 hours of illumination and 10 hours of darkness. Regular fluorescent aquarium lights should work fine for this. To keep them from eating the eggs, you should line the bottom of the tank with marbles or medium-sized gravel. If you're doing research and want to collect the eggs, a removable tray covered in plastic mesh with holes large enough to let the eggs drop through (but small enough to keep the adults out) will also work.
A single female may produce as many as 200 eggs in a single week. And once the eggs are laid in the water and fertilized, the developing transparent embryonic fish are very easy to look at under a microscope; their development can be easily monitored and documented over the three or four days it takes them to mature and hatch. An embryo's individual organs and parts can be marked with fluorescent dyes to make observations even easier.
The larvae and embryos are frequently used in studies to learn more about brain and spinal cord development; such research may provide insights into human ailments such as Parkinson's disease and spina bifida. Adult fish are used in a wide range of research and are used to study development of every part of the vertebrate body: bones, muscles, hemoglobin in blood, etc.