A cell-surface molecule that normally binds to folate might be targeted by Ebola and Marburg viruses as their entry point to people's cells. (p. 36)

Some nonstick coatings such as Teflon break down at high temperatures into undesirable compounds that persist in the environment. (p. 36)

Long-dismissed brain chemicals called trace amines have receptors on human cells and may play a role in depression and schizophrenia. (p. 37)

The above-average number and strength of hurricanes in the North Atlantic during the past 6 years may signal the beginning of a threatening weather trend for the United States, the Caribbean, and Central America. (p. 37)

An obscure optical effect called instrinsic birefringence has suddenly appeared as a threat to technology for making denser, faster microchips. (p. 38)

Gamma rays detected by the NEAR Shoemaker spacecraft after it landed on asteroid 433 Eros add to evidence that the rock is unaltered since the birth of the solar system. (p. 38)

Herpes simplex virus 1 has an affinity for cells with a mutation that marks many tumors, indicating how the virus may be refined as a cancer therapy and that certain new drugs might attack herpes itself. (p. 39)

Depressed people who benefit from either talk therapy or antidepressant drug treatment may experience similar brain changes, according to a pair of new studies. (p. 39)

Ever since astronomers first spied a comet 6 months ago and officially dubbed it C/2001 A2, the icy body has been breaking apart. (p. 41)

An icy body in the Kuiper belt, a reservoir of comets in the solar system beyond Neptune, is a record setter for the belt and bigger than Pluto's moon Charon. (p. 41)

Two California condors in the wild—a hatching and a just-released juvenile—died the same week, as a third went missing. (p. 41)

The narrow-leafed gentian, a mountain blossom, is the first flower shown to close when a thunderstorm apporaches. (p. 41)

Recent studies suggest that there may be more ways to create new species than Darwin imagined. (p. 42)

Farmers are finding that commercial wind power is the best new commodity to come along in years, one that can offer substantial year-round income. (p. 45)

Blood sugar concentrations that are too high or too low can impair thinking and, in the case of low blood sugar, driving ability. (p. 47)

The synthetic version of exendin-4, a compound in gila monster venom, helps insulin injections control blood sugar in people with type I, or juvenile-onset, diabetes. (p. 47)