Jumat, 31 Juli 2009
What Happened to the Neandertals?
The cover story of the August 2009 issue of Scientific American discusses the latest evidence and hypotheses for why the archaic humans called the Neandertals disappeared from Europe around 28,000 years ago. Older theories, that the Neandertals either interbred with modern humans or died in wars against them (the love versus war hypotheses), seem to be losing favor. A more recent hypothesis is that there were frequent and rapid changes in climate in Europe at the time, and that modern humans, by virtue of being more advanced in certain ways, were better able to adapt to the changes in weather and food supplies. The article goes on to describe the likely cultural, behavioral, and biological differences between the Neandertals and modern humans who lived in Europe 35,000 years ago, and how these differences might have affected modern humans’ success or the Neandertals’ ultimate failure.
Kamis, 30 Juli 2009
IGEM Calgary - CTV and NUTV's Introduction
Wow! CTV really kicked it up a notch compared to NUTV! :)
Podcast: UK's Guardian Science Weekly
http://download.guardian.co.uk/audio/kip/science/series/science/1247855895096/996/gdn.sci.090720.sc.science-weekly-podcast-synthetic-biology.mp3
Science Weekly: Rise of the biological machines
Synthetic biologist Paul Freemont describes a future in which purpose-built organisms will manufacture complex chemicals and drugs to order.
Science Weekly: Rise of the biological machines
Synthetic biologist Paul Freemont describes a future in which purpose-built organisms will manufacture complex chemicals and drugs to order.
Sabtu, 25 Juli 2009
Birth Control Method Failures
In Human Biology 5th ed. (p. 387) there’s a table of data provided by the U.S. Food and Drug Administration on the failure rates of various contraceptive methods. I’ve always felt that the reported failure rate for condoms of 10-20% seemed awfully high. Condoms are supposed to work, right?
Now there’s an explanation. Recent evidence shows that for both condoms and withdrawal, there’s a big difference between “perfect use” and “typical use”. If a couple actually uses a condom every time (no exceptions, folks), the annual failure rate is only about 2%. For withdrawal every time, the failure rate is about 4%. The problem is that in the heat of passion some couples “forget”, or convince themselves that not using a birth control method just this once won’t be a big deal. Under these more typical use conditions, the failure rates of condoms and of withdrawal are indeed closer to 20% per year.
If you’re going to rely on these contraceptive methods, don’t cheat!
REFERENCE: R.K. Jones. Better than nothing or savvy risk-reduction practice? The importance of withdrawal. Contraception 79:407-410, June, 2009.
Now there’s an explanation. Recent evidence shows that for both condoms and withdrawal, there’s a big difference between “perfect use” and “typical use”. If a couple actually uses a condom every time (no exceptions, folks), the annual failure rate is only about 2%. For withdrawal every time, the failure rate is about 4%. The problem is that in the heat of passion some couples “forget”, or convince themselves that not using a birth control method just this once won’t be a big deal. Under these more typical use conditions, the failure rates of condoms and of withdrawal are indeed closer to 20% per year.
If you’re going to rely on these contraceptive methods, don’t cheat!
REFERENCE: R.K. Jones. Better than nothing or savvy risk-reduction practice? The importance of withdrawal. Contraception 79:407-410, June, 2009.
Senin, 20 Juli 2009
Percocet, Vicodin May be Banned
A federal panel of experts advised the Food and Drug Administration (FDA) this month to ban two popular prescription painkillers, Percocet and Vicodin, from the market. The panel also recommended that the maximum allowable dose of acetaminophen in over-the-counter pills such as Tylenol be reduced from 500 mg to 325 mg. The FDA is expected to accept the panel’s recommendations.
Percocet and Vicodin are comprised acetaminophen plus a narcotic. According to the panel of experts, there is now sufficient evidence to conclude that high doses of acetaminophen over prolonged periods of time can cause liver damage.
It's worth noting that nearly all drugs, even some very good ones, can have unwanted side effects if they are abused.
You can read or see the news reports on the panel’s findings by Googling “FDA”, “Percocet”, and “acetaminophen”.
Percocet and Vicodin are comprised acetaminophen plus a narcotic. According to the panel of experts, there is now sufficient evidence to conclude that high doses of acetaminophen over prolonged periods of time can cause liver damage.
It's worth noting that nearly all drugs, even some very good ones, can have unwanted side effects if they are abused.
You can read or see the news reports on the panel’s findings by Googling “FDA”, “Percocet”, and “acetaminophen”.
Minggu, 19 Juli 2009
Getting That Caffeine Buzz
The latest entry into the world of marketing hype - “energy shots”, a mere two ounces of bad-tasting liquid loaded with caffeine. Manufacturers won’t say how much caffeine for proprietary reasons (and probably to add to the drinks’ mystique), but most energy shots are thought to contain on the order of 120-200 mg. That’s the equivalent of one to two ordinary cups of coffee or a 16-oz energy drink.
Energy shots may also contain B-vitamins, amino acids and various plant extracts, but these aren’t likely to give you much of an energy boost despite the products’ claims. And then there’s the cost – upwards of $3 apiece.
If it’s a caffeine buzz you need, what’s wrong with plain-old maximum strength (200 mg) No-Doz? It was your grandfather’s drug of choice nearly 50 years ago for pulling an all-nighter, and it still works. Plus it only costs about 20 cents per dose.
Energy shots may also contain B-vitamins, amino acids and various plant extracts, but these aren’t likely to give you much of an energy boost despite the products’ claims. And then there’s the cost – upwards of $3 apiece.
If it’s a caffeine buzz you need, what’s wrong with plain-old maximum strength (200 mg) No-Doz? It was your grandfather’s drug of choice nearly 50 years ago for pulling an all-nighter, and it still works. Plus it only costs about 20 cents per dose.
Selasa, 14 Juli 2009
Sabtu, 11 Juli 2009
Caloric Restriction and Longevity
It has been known for some time that severe caloric restriction can retard the aging process and prolong the life of a variety of species, from worms to mice. But skeptics of the idea that caloric restriction might also slow the aging process in humans point out that the metabolisms of worms and mice are quite different from that of humans.
Now a new study reports that caloric restriction slows the aging process in primates, too. Macaque monkeys that have been on a calorie-restricted diet (by 30%) for the past 20 years are living longer and are healthier than their age-matched control counterparts. Excluding animals that died of non-age-related causes (accidents for example), 50% of the animals on a normal diet have died of age-related causes, compared to only 20% in the restricted-diet group. The calorie-restricted animals also have fewer age-associated diseases such as diabetes, cancer, and cardiovascular disease. The study is still ongoing.
Now a new study reports that caloric restriction slows the aging process in primates, too. Macaque monkeys that have been on a calorie-restricted diet (by 30%) for the past 20 years are living longer and are healthier than their age-matched control counterparts. Excluding animals that died of non-age-related causes (accidents for example), 50% of the animals on a normal diet have died of age-related causes, compared to only 20% in the restricted-diet group. The calorie-restricted animals also have fewer age-associated diseases such as diabetes, cancer, and cardiovascular disease. The study is still ongoing.
Rabu, 08 Juli 2009
Wildfires, Evolution, and Ecosystems
Fires set by the forces of nature have existed on the Earth since the dawn of time, and as a result some plants have evolved to survive fires rather well. A few plants even require an occasional fire in order to release their seeds. But here’s an interesting notion; did certain plants evolve to encourage the spread of wildfires once they’ve started? After all, if the plant could survive the fire it might be a good way to kill off the competition. For those of you interested in evolutionary processes, see the recent well-referenced opinion article in the New York Times.
Minggu, 05 Juli 2009
Swine Flu Takes Hold in Argentina
Swine flu just won’t go away. A recent a sharp uptick in the number of deaths from swine flu in Argentina has moved that country into third place for the most swine flu deaths, after Mexico and the United states. And the timing couldn’t be worse; it’s winter in South America, the season when influenza viruses typically spread the easiest. Of special concern is that the death rate in Argentina (1.6%) is more than three times the world average.
We need to keep an eye on this pesky bug. Who knows what it could do in North America NEXT flu season? For the latest information on swine flu (also now called Pandemic H1N1), see the World Health Organization website.
We need to keep an eye on this pesky bug. Who knows what it could do in North America NEXT flu season? For the latest information on swine flu (also now called Pandemic H1N1), see the World Health Organization website.
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