By turning on a gene that's normally active only during embryonic development, researchers have restored hearing in deaf guinea pigs. (p. 115)

Enigmatic bursts of high-energy gamma rays produced Earth's atmosphere are stronger and more frequent than previously thought. (p. 115)

Ancient Chinese people may have used diamonds to polish their stone axes to mirrorlike finishes. (p. 116)

The dancing lights that paint Saturn's sky stands out from all other auroras observed in the solar system. (p. 116)

Three men who suffered left brain damage that undermined their capacity to speak and understand language still possessed a firm grip of mathematics. (p. 117)

Young zebra finches do badly at song practice for the first few hours after they wake up but then recover, and even improve, their musical skills. (p. 118)

An experimental test predicts which breast tumors will spread rapidly without treatment and which are likely to be less aggressive by tracking the activity of genes normally involved in mending injured tissue. (p. 118)

Migraines may be among the problems that stem from a common but rarely diagnosed heart defect, and researchers have discovered that repairing the defect cures some of the headaches. (p. 119)

Examining nearby reaches of the universe at ultraviolet wavelengths, a recently launched spacecraft has found regions of star birth in unexpected places. (p. 122)

One of the twin rovers on Mars has discovered the first meteorite ever found on a planet other than Earth. (p. 124)

Airborne particles in subterranean transit stations may be more damaging to human cells than are particles from street-level air. (p. 124)

In a feat of precision chemistry, scientists have locked a pair of hydrogen atoms inside a soccer ball–shaped carbon molecule known as a buckyball. (p. 125)

Whole-body computed tomography scans for asymptomatic disease do not appear cost-effective at this time. (p. 125)

A brain-imaging study indicates that right-handers and left-handers use different, corresponding neural regions to perceive parts of an object while ignoring the larger entity. (p. 125)

A drug derived from a component of vampire bat saliva can clear blood clots in the brains of people who have had strokes. (p. 126)

People who consume a lot of salt are nearly twice as likely to have a stroke as are people who consume less salt, even when their blood pressures are equivalent. (p. 126)

People recovering from a stroke have less vitamin D in their systems than do healthy peers, which could explain why stroke patients often have low bone density and risk breaking bones. (p. 126)

Blacks living in southern U.S. states have a greater risk of dying of stroke than do blacks living in northern states. (p. 126)

(p. 127)