Новости науки и техники в "Scientific American"

THE FINAL COMPONENT OF ANTHRAX'S TOXIC TRIAD

After the bioterrorism of last fall, researchers are more anxious than ever to find drugs to combat anthrax. Now scientists have determined the structure of the last of three poisonous proteins that make up the bacteria's deadly toxin. This third component, dubbed edema factor (EF), may very well represent the anthrax toxin's Achilles' heel.

HIGH-TEMPERATURE SUPERCONDUCTORS BEHAVING STRANGELY

For now, the closest thing to a room temperature superconductor is a high-critical temperature (Tc) one. Unlike superconducting metal alloys, which must remain near absolute zero to display a resistance- free electron flow, high-Tc superconductors operate at around 77 degrees Kelvin. A new report shows that the electrons in high-Tc superconductors also behave differently from those in the conventional variety.

TESTOSTERONE PREVENTS KEY ALZHEIMER'S ABNORMALITY

New research suggests that testosterone treatment could prevent or delay the onset of Alzheimer's disease in aging men and women. According to findings detailed in a report released by the Proceedings of the National Academy of Sciences, doses of the hormone, given alone or in combination with estrogen, staved off a key chemical aberration characteristic of the disease in rats.

NEW BOOK: - THE SECRET LIFE OF DUST: FROM THE COSMOS TO THE KITCHEN COUNTER, THE BIG CONSEQUENCES OF LITTLE THINGS by Hannah Holmes

Dust, science writer Holmes tells the reader, is so ubiquitous that "by the time you have read this far [11 lines into her first chapter], you may have inhaled 150,000 of these worldly specks." Billions of tons of dust rise from Earth every year, from deserts, volcanoes, oceans, living things and factories. Billions of tons fall to Earth every year, not only from what rose but also from space. This enormous traffic of tiny things has profound effects, good and bad, on Earth and on living organisms. Holmes makes an engaging story of the worldly specks.

CARBON NANOTUBES COULD SERVE AS ULTRAFAST OSCILLATORS

The minuscule size of most nanotubes - hollow cylinders of carbon measuring only a few billionths of a meter wide - boggles the mind. Even more astounding may be that scientists can conceivably nestle these straws inside one another like Matryoshka dolls, with the inner set of tubes sliding in and out a billion times a second. Such gigahertz oscillators could aid in the creation of nanomechanical devices.

SPYING SEALS TRACK ELUSIVE ANTARCTIC FISH

To study the behavior of two elusive species of fish, scientists have enlisted the help of some unlikely photographers: seals. Antarctic silverfish and Antarctic toothfish, though abundant in the Southern Ocean, spend much of their time at great depths and under thick ice, making observation difficult. But as the fishes' natural predator, the Weddell seal knows exactly where to find them.

ASK THE EXPERTS - WHAT IS ANTIMATTER?

R. Michael Barnett of the Lawrence Berkeley National Laboratory and Helen Quinn of the Stanford Linear Accelerator Center offer an answer.