Brain-scan data show that the brains of children diagnosed with attention-deficit hyperactivity disorder are slightly smaller than those of their peers who are free of psychiatric disorders. (p. 227)

Documents detailing the rise of modern physics and Albert Einstein's development of the general theory of relativity have sold at an auction for nearly $1.8 million. (p. 227)

A newly discovered celestial body appears to be the largest object that scientists have found in the solar system since their detection of Pluto in 1930. (p. 228)

Minuscule amounts of over-the-counter weed killers impair reproduction in mice. (p. 228)

The 2002 Nobel prizes pay tribute to an international sampling of scientists who developed powerful new techniques for expanding the horizons of research. (p. 229)

A newly synthesized form of Vitamin D induces bone-making cells to capture calcium and fortify bone mass in rats, suggesting it might work against osteoporosis in people. (p. 230)

A study of leghorn chickens has linked hormone concentrations in a hen's eggs to her rank in the pecking order. (p. 230)

New research and policy developments aim to curb the wasteful and gruesome practice of killing sharks solely for their fins. (p. 232)

Researchers are looking for more sustainable ways to generate hydrogen, which burns cleanly but is typically made from fossil fuel. (p. 235)

The discovery of hieroglyphic-covered steps on the side of a Maya pyramid has yielded new information about warfare between two competing city-states around 1,500 years ago. (p. 237)

Several types of whales, river dolphins, the great white shark, and an unusual camel are among animals designated to receive new or heightened protection under a United Nations treaty. (p. 237)

A gene variant reduces people's response to the stress hormone cortisol, and people with the variant are less likely to have risk factors for heart disease and diabetes. (p. 237)

Sandpipers' special wax for their wings during the breeding season may have less to do with courting a mate and more to do with sitting on eggs. (p. 237)

Scientists have developed a test that uses the eye's ability to adapt to darkness as a test for age-related macular degeneration, the most common cause of blindness in elderly people. (p. 238)

A compound made during inflammation, a natural reaction to injury, can induce optic nerve regeneration in a lab-dish concoction including rat retinal ganglion cells. (p. 238)

Right-handed golfers using a conventional grip move their head and eyes more during putts than they do when using a cross-handed or one-handed grip, suggesting these alternative grips might work better. (p. 238)

By restarting the subdued self-destruct signal in cancer cells, researchers studying eye cancers have found a way to stop these cancers in cell cultures and in a rabbit model. (p. 238)