The most detailed portrait ever taken of the radiation left over from the Big Bang provides fresh evidence that the universe began with a tremendous growth spurt, expanding from subatomic scales to the size of a grapefruit in less than a trillionth of a second. (p. 163)

To clear clogged stents, the small mesh cylinders that doctors implant to prop open blood vessels, inserting a second, specially-coated stent works better than treatment with radiation. (p. 163)

Dozens of precariously balanced rocks in southern California tell a consistent story that earthquakes at nearby faults in recent millennia haven't exceeded magnitude 7. (p. 164)

A new material made of nanometer-sized protein particles appears to be able to bridge the gap between severed nerves. (p. 164)

Two new studies offer a glimpse of extensive remodeling of nerve connections in the brain's outer layer, or cortex, during adulthood in mice and monkeys. (p. 165)

A small frog living beside Chinese hot springs may be the first amphibian known to use ultrasound in its calls. (p. 165)

With DNA origami, researchers can make complex nanostructures. (p. 165)

For her water-quality research project, an 18-year-old from Utah earned top honors among 40 competitors in the final phase of the annual Intel Science Talent Search. (p. 166)

Increasing concerns about the efficacy and safety of a popular class of antidepressant drugs, selective serotonin reuptake inhibitors, especially in depressed youth, has sparked regulatory action and scientific debate. (p. 168)

New digital images demonstrate that artificial light from urban areas penetrates deep into some of America's most remote wild places, where it may disrupt ecosystems that have evolved with a nightly quota of darkness. (p. 170)

An ongoing flurry of fossil finds is triggering a reevaluation of how early mammals and their close kin eked out an existence during the Age of Dinosaurs. (p. 173)

Proteins taken from a spherical virus and combined with pieces of DNA can form tubular nanostructures, researchers report. (p. 174)

A change in a single letter of a rice plant's genetic code gave it the ability to hold onto grains until harvest. (p. 174)

Natural selection has continued to propagate survival-enhancing gene variants in human populations over the past 10,000 years, according to a new genetic analysis. (p. 174)

Complying with a request from the Environmental Protection Agency, the companies that make the likely carcinogen perfluorooctanoic acid (PFOA) have agreed to phase out its release worldwide by 2015. (p. 174)

(p. 175)