Developments to Watch
Peering Through the Microscope
A roundup of reports from this year's U.S. confab of scientists
In January, 4,000 scientists gathered in Anaheim, Calif., to discuss a dizzying array of topics, such as El Nino, human mating patterns, and anti-aging research. This year's meeting of the American Association for the Advancement of Science included research on disease and environmental hazards as well as big-picture stuff--for example, "The Fate of the Universe." Several hundred reporters attended, including a contingent from BUSINESS WEEK. Here is a report:
SCIENTISTS ARE SHRINKING MACHINES INTO THE REALM OF THE MICROSCOPIC, carving minuscule motors and gears out of silicon. But at the University of California at Los Angeles, chemist Fraser Stoddart is thinking much smaller. His goal is to create machines fashioned from individual molecules. "It's one of the challenges for the next century," he says.
In the labs of Stoddart and others, the work is showing promise. Stoddart's team, for instance, has created molecules shaped like rings, rods, and dumbbells. With clever chemistry, researchers can get different shapes to interact in repeatable ways. In one system, scientists have been able to drive a rod-shaped molecule in and out of the cavity of a ring-shaped molecule--in essence, creating a tiny piston. In another, Stoddart can slide a ring back and forth along the bar of the dumbbell molecule--a miniature switch. And they have used combinations of rods and rings to create logic gates, in which different chemical inputs (such as dumping in acids or bases) cause the rods and rings to link up or separate, giving the whole chemical solution different properties.
So far, Stoddart's molecular machines function only in liquid, a big limitation to practical applications. The scientists are now seeking ways to hook the molecular machines onto a solid surface. Once that's done, it may be possible to create unimaginably small versions of everything from motors to computers.By John Carey
A FRUIT FLY NAMED METHUSELAH
PEOPLE HAVE BEEN SEEKING THE FOUNTAIN OF YOUTH FOR CENTURIES. And some scientists think they may have found it, in the form of antioxidants such as vitamins A, C, and E. In fact, they are using antioxidants to extend the life of fruit flies.
According to R.S. Sohal of Southern Methodist University in Dallas, aging is caused in part by free oxygen radicals that are produced as cells break down nutrients. These oxygen radicals damage the mechanisms that power our cells. With age, such damage appears to increase exponentially, probably because harmful oxidants are present in greater concentrations than antioxidants, which roam the body cleaning up free radicals.
To test this hypothesis, Sohal engineered fruit flies that produced high levels of two antioxidants. He found that the genetically altered flies lived 34% longer than normal and were far more active. But Sohal cautions that there's a lot of research to be done before it's established that antioxidants will do the same for humans.By Ellen Licking
THE FUNGUS THAT'S EATING FLORIDA
FLORIDA'S CORAL REEFS MAY BE EARLY VICTIMS OF GLOBAL WARMING. A team of Cornell University ecologists say they have found that 100-year-old corals growing around Florida are succumbing to infections they formerly survived. The team suggests that higher ocean temperatures could be putting stress on the corals, increasing their susceptibility to disease. The Coral Reef Monitoring Program (CRMP), funded by the Environmental Protection Agency, reports that 82% of sites in the Florida Keys show signs of disease. And while coral reefs worldwide have suffered damage recently, researchers say those around Florida are particularly vulnerable because of substantial temperature fluctuations and freshwater runoff.
The Cornell biologists, led by C. Drew Harvell, report that a common soil-dwelling fungus called aspergillus has been swept into the sea through erosion, infecting up to 40% of the sea fan corals in the keys. It collects on the flexible, fan-shaped surface of the coral, causing dark purple-colored lesions that kill it. James W. Porter, a coral reef expert at the University of Georgia at Athens, says that the land-to-sea spread of aspergillus is a serious cause for concern--and a potential sign of the damage that humans are doing to the reef ecosystem.By Ellen LickingReturn to top