3 сентября 2002 г.
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Новости науки и техники в "Scientific American"
3 сентября 2002 г. |
STUDY SUGGESTS SMALLPOX VACCINE OFFERS LONG-TERM PROTECTIONThe results of a new study suggest that the standard smallpox vaccine confers surprisingly long-lasting immunity. Vaccinations are generally thought to last seven to 10 years, but researchers recently reported that people vaccinated decades ago can still have a strong immune response to the smallpox virus's close cousin, vaccinia.TINY CRYSTALS TELL STORY OF EARTH'S EARLIEST-KNOWN METEOR IMPACTA number of near-Earth asteroids have made headlines lately, but, thankfully, none is likely to hit us anytime soon. That wasn't the case in our planet's early years. Now scientists say they have the first direct evidence--in the form of layers of ancient rock from Australia and South Africa--that our planet experienced a meteorite impact 3.5 billion years ago. According to their report, the offending body was roughly twice the size of the asteroid that killed the dinosaurs 65 million years ago and created a tsunami that raced around the globe at 500 miles per hour.BOOKSTORE: ENVISIONING SCIENCE: THE DESIGN AND CRAFT OF THE SCIENCE IMAGE by Felice FrankelFrankel, a science photographer and research scientist at the Massachusetts Institute of Technology, presents "a guide to photographing science material." As that alone, it would be of limited interest. But two other attributes give the book a far broader appeal. One is her goal of encouraging science workers "to find a place in your research for a new way of seeing and presenting your work" so as to see "the potential of using your images to communicate to those outside the research community." The other is the pictures, a stunning array that will communicate with any reader. Open the book at random, and your eye will be dazzled: a three-centimeter drop of ferrofluid, gold on gold (one-centimeter patterned chips on a gold wafer), or a flowerlike yeast colony illuminated by daylight from a window.NEW PROCESS COULD HARNESS HYDROGEN FUEL FROM PLANTSPlant-based fuel could be coming to a gas station near you. According to a recent report published in the journal Nature, scientists have succeeded in manufacturing hydrogen from a glucose solution derived from biomass. If sufficient fuel were readily available, hydrogen- powered electric vehicles (which don't produce greenhouse gases in their exhaust) could help curb our reliance on fossil fuel-guzzling cars.VIRAL WORKHORSESEmptied of their infectious nucleic acids, viruses can make surprisingly adaptable tools for nanoengineers. As a result, researchers are taking advantage of some viral systems to develop clever applications for drug delivery, medical imaging and nanoelectronics.HOW GECKOS GET A GRIPA growing body of evidence indicates that gecko lizards cling to surfaces with the help of hairlike projections. The gecko hairs are so tiny, however, that they operate not by catching on substrate irregularities, but by facilitating the formation of molecular bonds that create electrodynamic attraction between the gecko's feet and the surface upon which it is walking.ASK THE EXPERTS: HOW DOES FINGERPRINT POWDER WORK?Forensic scientists Christine Craig and Jason Byrd explain.