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Consider, for example, the massive forest diebacks occurring across the West. "People tend to think of forests as pretty slow changing," says Craig Allen, an ecologist with the U.S. Geological Survey. "But once certain thresholds are exceeded, very rapid changes can occur." In some cases, thirsting trees perish because their circulatory systems--the long tubular columns in the trunk that transport water from the roots to the crown--collapse. In other cases, the trees become so weak they can no longer fend off insects and disease...
...connection between drought and wildfires is strong, says Thomas Swetnam, head of the University of Arizona's Laboratory of Tree-Ring Research. And the most dangerous fires, he says, occur when droughts follow years that are unusually wet. That's because generous rains encourage trees, shrubs and grasses to grow, providing the fuel that stokes forest fires. This pattern of wet preceding dry, Swetnam thinks, helped feed the intense blazes that raged through the Southwest shortly after 1850, taking out huge stands of conifers. So, if a new El Nino materializes later this year, as some experts expect...
...nonprescription drugs. More than one-third of these mistakes involved adults 65 and older. "The average hospitalized patient in this age group gets between eight and 14 different medications every day," says Dr. Christine Cassell, president of the American Board of Internal Medicine. "It's not surprising that mistakes occur...
...rational numbers 1/8, 1/32, 1/96, 5/1536...that occur on the right-hand sides of these formulas are remarkably ubiquitous in mathematics and the mathematical sciences: they pop up in contexts ranging from power series for trig functions, to black-body radiation in physics, to abstruse mathematical disciplines such as K-theory and homotopy groups,” Elkies wrote in an e-mail...
...boom in motor-vehicle purchases by the newly prosperous?has been a staggeringly high traffic-fatality rate. With just 16% of the world's cars, trucks, buses and motorcycles, Asia accounts for more than half of the roughly 1.2 million traffic fatalities that the World Health Organization (WHO) estimates occur globally every year. More than 600,000 Asians are killed and another 9.4 million are severely injured in traffic accidents annually...