A new type of X-ray machine operates at room temperature by producing X-ray-generating electrons with carbon nanotubes instead of traditional heated metal filaments. (p. 3)

A new study of adolescents suggests that widespread environmental pollutants such as PCBs and dioxins may delay sexual development. (p. 3)

Only a few days after birth, babies already home in on faces that fix them with a direct gaze and devote less attention to faces with eyes that look to one side. (p. 4)

Men's and women's brains react differently to hunger, as well as to satiation. (p. 4)

Scientists have exploited a method for detecting the orientations of magnetic fields to achieve a remarkable leap in detector sensitivity. (p. 5)

A fossil originally misidentified as an ancient fish turns out to be the nearly intact remains of a four-limbed creature that lived during an extended period noted for its lack of fossils of land animals. (p. 5)

Brain surgery in beetles reveals yet another way that having sex can shorten life. (p. 6)

A United Nations panel concluded that, in fried, grilled, and baked foods, the formation of acrylamide, a carcinogen and nerve poison in rodents, constitutes "a serious problem." (p. 6)

A few aphid species that live socially in groups raise their own armies of teenage female clones. (p. 8)

The hunt for a rare, hypothetical nuclear transformation known as neutrinoless double-beta decay may answer one of the most urgent questions in physics today: How much do elementary particles called neutrinos weigh? (p. 10)

An experimental drug seems to assail obesity through dual biological actions. (p. 13)

Researchers are uncovering the role of molecular forces in cartilage's ability to resist compression. (p. 13)

Older persons experience elevated systolic blood pressure for at least 1 year after a spouse with Alzheimer's disease enters a nursing-care facility or dies. (p. 13)

Even self-pollinating coffee plants benefit substantially from visits by insect pollinators. (p. 13)

Exotic cousins of protons and neutrons known as doubly-charmed baryons may have made their laboratory debut. (p. 14)

People with an inherited form of obesity caused by constant hunger pangs have higher-than-normal blood concentrations of ghrelin, a hormone believed to boost appetite. (p. 14)

A study of sexual dysfunction in mutated mice may help explain the connection between smell and appetite. (p. 14)