Jumat, 24 Oktober 2008

Who Were the Flores People?

Since their discovery in 2004, the origin and identity of a diminutive people who lived on the island of Flores, Indonesia 70,000 to 12,000 years ago have been the hot topic among paleoanthropologists (see the Current Issue in Human Biology 5th ed., pp. 520-521.) The discoverers immediately claimed to have unearthed a new human species, which they named Homo floresiensis. Nay-sayers still dispute the claim, saying that the one skeleton found so far, named LB1, is nothing more than a diseased human with microcephaly.

Well, it seems that the new-species proponents are gaining ground these days. Analysis of LB1’s hands and feet suggest that this is not the skeleton of a modern but diseased human. Her wrist bones and especially her feet are closer to those of Homo erectus, an African Hominid that lived in Africa more than a million years ago. Her feet are so long that scientists think she must have walked with a high-stepping gait and been a poor runner. How Homo floresiensis reached Indonesia and survived there for over 50,000 years is a mystery.

For a good look at the one skeleton unearthed so far, see “When Hobbits (Slowly) Walked the Earth”, Science April 25, 2008, pp. 433-435. You can get the article online at www.sciencemag.org - search for "When Hobbits".

Rabu, 15 Oktober 2008

What's in That Energy Drink?

How much caffeine is there in those so-called “energy drinks”? Take a look at the article in press in the journal Drug and Alcohol Dependence (2008) by C.J. Reissig, et al., entitled “Caffeinated energy drinks – A growing problem”, available online at www.sciencedirect.com. According to Table 1 in the article, some of them are pretty high-powered. Most energy drinks have about the same caffeine concentration as brewed coffee, but considering that some drinks come in 16- or even 24-oz sizes, that's a lot of caffeine.

Sales of these products continue to climb. Health officials are growing increasingly concerned by reports of acute caffeine intoxication, dependence, and withdrawal among children. There is also a trend toward the combined use of energy drinks and alcohol among young adults.

Which ones do your students drink? Do they know what’s in them?

Selasa, 14 Oktober 2008

Portable Music Players and Hearing Loss

In Human Biology, 5th edition we warn that portable music players are capable of sound levels that could permanently damage one’s hearing (“Do Portable Music Players Endanger Your Hearing?” p. 293). A commission of the European Union apparently agrees. In an opinion made public yesterday, the EU Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) concluded that users of portable music players who listen at high volumes for more than an hour a day risk permanent hearing loss. Their best guess is that 5-10 percent of listeners, or up to 10 million people in the EU, fall into that category. They warn that although listening at high volumes may not seem to have an immediate effect, it still may lead to hearing loss later in life.

The European Commission is planning a conference for early 2009 to discuss the committee’s findings with industry, consumers, and governments, and to consider whether there is a need for tighter controls over portable music players. I would not be surprised to see new legislation emerge that limits the maximum sound volumes attainable with portable music players.

SCENICOR’s 80-page preliminary report, released in June for public comment, is available online.

Minggu, 12 Oktober 2008

Ginkgo and Prevention of Stroke

The herbal remedy Ginkgo biloba may help prevent strokes, according to researchers at Johns Hopkins University. The researchers induced strokes in mice after treating some of the mice with various doses of Ginkgo. The mice pretreated with Ginkgo had nearly 50 percent less brain damage after stroke than the untreated mice. The researchers speculate that Ginkgo may be protective against stroke because it increases the level of an antioxidant enzyme that eliminates free radicals. And free radicals reportedly have damaging effects in living cells, even after a stroke-causing clot is removed or dissolved.

Researchers caution that so far, the research has only been done on mice. Still, it’s encouraging to see herbal remedies being subjected to the same kind of careful scientific scrutiny that has traditionally been applied to therapeutic drugs. This is exactly what we had hoped for, as discussed in Human Biology 5th ed. in the Current Issue essay entitled “Antioxidants: Hope or Hype?” (pp. 42-43). In time perhaps we’ll know the real story behind herbal remedies, and not have to rely on anecdotes and hype.

Kamis, 09 Oktober 2008

New Drug Test for Athletes

The International Olympics Committee plans to retest many of the nearly 1,000 blood samples it collected during the 2008 games in Beijing for a synthetic analogue of the natural hormone erythropoietin, called CERA. CERA is a so-called “designer drug” that was supposed to escape detection. But a test is now available to detect CERA, and several Tour de France cyclists subsequently were found to have used it.

According to World Anti-Doping Agency rules, an athlete’s blood may be retested for up to eight years after an athletic event. The International Olympics Committee keeps blood samples for eight years for situations like this, in which a new test is developed to detect a previously undetectable performance-enhancing drug. It’s just another way that sports authorities try to keep up with athletes who are willing to cheat. Sports authorities hope that the knowledge that an athlete might still be stripped of his/her medals up to eight years after a competition will deter some athletes from using drugs in the first place. But the desire to win is strong, and no one knows if the strategy will work.

Rabu, 08 Oktober 2008

More on Sequestering Carbon

A good article on current and future methods of carbon sequestration for reducing greenhouse gases is “Down with Carbon” (Science News May 10, 2008, pp. 18-23.) The article is written at a level that students will understand. Some promising possibilities for long-term storage include the bottom of the ocean, in sandstone/saline aquifers deep underground, or in volcanic rock formations. There are also some interesting synthetic materials called zeolites in development that can soak up carbon.

Instructors will be interested in the detailed report by the Intergovernmental Panel on Climate Change (IPCC) entitled “Carbon Dioxide Capture and Storage – Summary for Policymakers”. The article has some great illustrations that would be useful in teaching. They can be used free with acknowledgment.
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