Новости науки и техники в "Scientific American"

CAUGHT OFF GUARD

Chinese officials have issued an extraordinary apology, effectively admitting that months of secrecy and denial after the mysterious disease now known as SARS appeared last November created a case study in how not to handle an infectious disease outbreak. But in the end, China might have done the world a favor of sorts by providing a test of global readiness for an even more devastating future epidemic, whether naturally occurring or unleashed in an act of terrorism.

LIKE FINE WINE, PERSONALITY IMPROVES WITH AGE

Growing older gives us much to grumble about, but new findings may help to offset those woes: personality, scientists say, appears to improve with age. Some experts argue that personality is genetically programmed to stop changing at a certain age. Others assert that some aspects may morph throughout adulthood, but not much. The new work suggests that personality is plastic and that the changes that come with age are generally for the better.

BOOKSTORE: WHAT DOES A MARTIAN LOOK LIKE? THE SCIENCE OF EXTRATERRESTRIAL LIFE by Jack Cohen and Ian Stewart

The authors of this book also see a possibility of extraterrestrial life. "We now know that there are many planets out there in the galaxy, and we have good grounds for supposing that a number of these will have life." It may be strange life, though, they say, nothing like what we know on Earth. On those principles, Cohen and Stewart (respectively, a reproductive biologist and a professor of mathematics at Warwick University in England) lay a basis for what they call xenoscience - knowledge of the strange. They draw on serious science - biology, chemistry, astronomy and physics - and also on science fiction, because the best of it has "made some useful contributions to the scientific understanding of possibilities for alien lifeforms."

LARGE FISH POPULATIONS IMPERILED

For weekend fishermen, there are many tall tales about "the big one that got away." The results of a new study indicate that big fish are indeed hard to catch. But disturbingly, the results suggest that's because the world's large fish - tuna, marlin, swordfish, sharks, cod and halibut among them - have been so exploited by industrial fisheries that 90 percent of them have disappeared from the sea.

NEANDERTALS NOT AMONG OUR ANCESTORS, STUDY SUGGESTS

The story of where modern humans came from has never been cut-and- dried, but two theories occupy the forefront of the debate. According to the Out of Africa model, Homo sapiens arose as a new species approximately 150,000 to 200,000 years ago in Africa and went on to replace archaic humans such as the Neandertals. The multiregional evolution model, in contrast, holds that archaic populations, the Neandertals among them, contributed to the modern human gene pool. A new analysis lends support to the former model, suggesting that moderns replaced Neandertals without interbreeding.

WAR MAY HAVE STIMULATED SPREAD OF AIDS VIRUS IN AFRICA

In addition to the obvious destruction war can wreak, violent conflicts may lead to the spread of epidemic diseases. One of the viruses that causes AIDS, HIV-2, may have risen to epidemic status in West Africa as a result of an independence war fought under particularly unsterile conditions.

ASK THE EXPERTS: HOW DO FOOD MANUFACTURERS CALCULATE THE CALORIE COUNT OF PACKAGED FOODS?

Jim Painter, an assistant professor of food science and human nutrition at the University of Illinois, explains.