Новости науки и техники в "Scientific American"

BOOKSTORE: THE END OF STRESS AS WE KNOW IT by Bruce McEwen, with Elizabeth N. Lasley

The stress response--fight or flee when confronting danger - has served humans well over the aeons, but under the multiple pressures of modern living it gets overworked. Chronic stress can cause health problems: cardiovascular diseases, disorders of the immune system, and afflictions of the mind "if normal feelings of distress and demoralization tilt towards clinical depression or anxiety." The message from McEwen, head of the Milliken Hatch Laboratory of Neuroendocrinology at the Rockefeller University, is that one does not have to fall victim to stress. "We cannot, and should not, eliminate the fight-or-flight response, for it is a powerful, highly sophisticated response. But we will be able to find ways of keeping the stress resource in balance, so that it works for us and not against us." Better-targeted medications will help. But "the best way to deal with stress is by maintaining our physical and emotional health."

MILITARY AIRCRAFT OF THE FUTURE

While the Army's fleet of Future Combat Systems vehicles are being designed to be quickly and easily transported to any trouble spot in the globe, there are some doubts as to whether the existing fleet of military transport planes, particularly the aging C-130, are up to the task. It seems clear that as the Army's ground forces evolve for future battles, so must its air-transportation systems.

NEW THEORY OF THE ORIGIN OF BIRD FLIGHT TAKES WING

Early birds may have used their wings not for flying, but for running. By flapping their front appendages, the animals could have gained more traction as they were running up steep inclines. So argues Kenneth Dial of the University of Montana in a newly published report.

WORM GENOME SURVEY REVEALS FAT-REGULATING GENES

Scientists are one step closer to unraveling the genetic secrets behind why some people become obese and others stay effortlessly slim. Gary Ruvkun and Kaveh Ashrafi of Massachusetts General Hospital and their colleagues have surveyed an entire genome--that of the microscopic worm Caenorhabditis elegans--to identify the full panoply of genes involved in regulating fat storage. The work may help pinpoint breakdowns in communication between the brain and fat cells in a variety of animals.

WRIGGLING ENERGY SOURCE MAY POWER AURORAS

Sky watchers at high latitudes are often rewarded with stunning celestial shows known as auroras. Conventional theory holds that large-scale electric currents flowing along the earth's magnetic field lines power the displays. Now researchers suggest another source of energy for the heavenly exhibitions. Slinky-like wriggling of the magnetic field lines may help fuel aurora borealis events.

A MILDER MAN-EATER?

The legend of the Tsavo man-eaters holds that two lions killed and devoured 135 workers constructing a bridge in Kenya in 1898. Now scientists are suggesting that the story is just that: a legend. Their findings indicate that the animals most likely killed fewer than 30 men. Moreover, they argue that the Tsavo lions were not aberrant, but that their actions were instead a function of changing environmental conditions.

ASK THE EXPERTS: HOW DOES A FLAME BEHAVE IN ZERO GRAVITY?

Chemist Kenneth D. Schlecht of the State University of New York College at Brockport explains.