Mental retardation placements in U.S. schools rose dramatically in the first five years after a commonly used IQ test was revised, raising concerns about how IQ scores are used to diagnose mental retardation. (p. 259)

Most chicken eaten in the United States contains 3 to 4 times as much arsenic as is present in other kinds of meat and poultry. (p. 259)

A polymer microchip implanted under the skin could deliver multiple doses of medications at programmed intervals, eliminating the need for pills and injections. (p. 260)

A potential AIDS drug may also slow the growth of deadly brain tumors. (p. 260)

Thyroid-stimulating hormone plays an unexpected role in bone remodeling. (p. 261)

A newly released image shows dramatic details of the Crescent nebula, a giant gaseous shell created by outbursts of a massive star about to explode as a supernova. (p. 261)

New lab experiments and computer analyses may explain how some of the heftiest four-legged dinosaurs ever to walk on Earth could have left trackways that include the imprints of only their front feet. (p. 262)

Scientists have for the first time directly observed the onset in liquid helium of superfluidity—a quantum-mechanical state in which liquids flow without friction—as helium atoms accumulated one by one to form a droplet of liquid around a gas molecule. (p. 262)

An earth scientist's proposed alternative periodic table of elements is emblematic of the growing desire among scientists to recast this 130-year-old chart. (p. 264)

New studies have begun linking toxic risks with a ubiquitous family of flame retardants. (p. 266)

Eating foods flavored with cocoa powder as opposed to other flavorings stimulates surplus production of the sugar-processing hormone insulin, but the metabolic implications of the finding aren’t yet known. (p. 269)

The lifetime in blood of flame- retarding diphenyl ethers, now-ubiquitous pollutants, ranges from 2 weeks to 2 years, Swedish researchers find. (p. 269)

Sending subliminal vibrations to nerves on the bottoms of feet helps people, especially the elderly, keep their balance. (p. 269)

Two studies suggest that veterans of the 1991 Gulf War are at elevated risk of developing the fatal neurodegenerative condition amyotrophic lateral sclerosis (ALS) compared with other military personnel and with the general population. (p. 269)

Using a newly discovered bacterium that both frees electrons from sugars and injects those charges straight into electric circuits, scientists have created a fuel cell that converts carbohydrates to electricity with extraordinary efficiency. (p. 270)

Giving healthy newborns whose mothers are infected with HIV a combination of anti-HIV drugs shortly after birth makes the infants less likely to contract the virus through breastfeeding. (p. 270)

An extrasolar planet that tightly orbits its parent star is heavier than astronomers had thought. (p. 270)

An object orbiting a distant star is too heavy to be a planet, researchers have concluded. (p. 270)

Letters from the Oct. 25, 2003, issue of Science News. (p. 271)