Новости науки и техники в "Scientific American"

COLD WAR WEAPONS TESTING INCREASED HUMAN DNA MUTATION RATE

The Cold War ended more than a decade ago, but scientists continue to assess its effects. From 1949 to 1956, a series of aboveground Soviet atomic tests at the Semipalatinsk nuclear facility in Kazakhstan exposed the local population to ionizing radiation. Now, some 40 years later, researchers have discovered a significant increase in the genetic mutation rates of several generations of families that lived nearby.

SCIENTISTS CREATE CARBON NANOTHERMOMETER

Scientists continue to create new uses for carbon nanotubes, tiny cylinders comprised of pure carbon. A new paper describes a thermometer made out of a column of carbon just 10 micrometers long. The nanodevice can measure temperatures between 50 and 500 degrees Celsius and "should be suitable for use in a wide variety of microenvironments."

BOOKSTORE: WHAT EVOLUTION IS by Ernst Mayr

"What I have aimed for," Mayr writes, "is an elementary volume that stresses principles and does not get lost in detail." What the reader gets from this giant in the field of evolutionary biology is a fine basic account of the developing understanding of evolution from ancient times to the present. Mayr presents a spirited defense of Darwinian explanations of biology as well as confronting the reductionist approach that tries to focus all evolutionary phenomena on the gene; he shows instead that evolution must consider two crucial units--the individual and populations.

STUDY LINKS USE OF TANNING LAMPS TO INCREASED RISK OF SKIN CANCER

Each year millions of Americans visit tanning salons in search of that "healthy glow." But if you think tanning beds are safe alternatives to sunbathing, think again. The results of a new study suggest that people who use these devices may have an increased risk of developing skin cancers.

A NEW REPORT EXPLAINS THE PHYSICS OF CRUMPLED PAPER

Crumpling a sheet of paper seems simple enough and certainly doesn't require much effort, but explaining why the resulting crinkled ball behaves the way it does is another matter entirely. Once scrunched, a paper ball is more than 75 percent air yet displays surprising strength and resists further compression, a fact that has confounded physicists. A new report, though, describes one aspect of the behavior of crumpled sheets: how their size changes in relation to the force they withstand.

RISING CO₂ LEVELS COULD FORCE SHIFT IN FERTILIZER USE

Over the past two centuries, atmospheric carbon dioxide concentrations have risen by nearly 30 percent. Global warming concerns aside, scientists long thought the trend would benefit plants, which use CO₂ to manufacture the chemical energy they need. But in recent years, research has shown that it's not quite that simple. For one thing, it appears that although plants initially process the additional CO₂, the accelerated assimilation declines after a few days or weeks. New research sheds light on why this happens.

ASK THE EXPERTS: HOW DO YOU GET LARYNGITIS?

Scientific American spoke with Rebecca N. Gaughan, an ears, nose and throat doctor in private practice in Olathe, Kansas to learn the answer.