Drastic weight loss achieved through gastric bypass and other stomach surgeries improves long-term survival for very obese people. (p. 115)

Some cases of obesity may result from infection by a virus that can transform adult stem cells into fat-storing cells. (p. 115)

In noisy surroundings, normally faithful female zebra finches flirt with unfamiliar males. (p. 116)

Mice lacking a gene that makes a certain brain protein display behaviors much like those of people with obsessive-compulsive disorder, a poorly understood psychiatric ailment. (p. 116)

The debris from an ancient collision of galaxy clusters seems to show cosmic dark matter behaving in a puzzling way. (p. 117)

A delicate quantum measurement counts photons without destroying them. (p. 117)

The western coast of Siberia lacks river deltas because of the way the terrain has subsided since the end of the last ice age. (p. 118)

Turning cellulose from plants into ethanol for fuel could help lower greenhouse-gas emissions—but the conversion is far from straightforward. (p. 120)

The events of 9/11 put new urgency into efforts to design buildings able to withstand the structural damage that fire can cause. (p. 122)

The male Anna's hummingbird impresses females and intimidates other males by making a whipping sound with its tail feathers. (p. 125)

In social amoebas, sluglike clusters of usually independent organisms, certain cells take on a protective role that hints at the origin of immune systems in higher animals. (p. 125)

Throwing tiny particles into the atmosphere to counteract global warming could cause extended droughts and other weather disruptions. (p. 125)

An epidemic of hyperthyroidism in house cats may be the result of environmental exposure to certain flame retardants. (p. 125)

In mice, treatment with lithium assists in the production of a bone-repair protein and improves the healing of fractures. (p. 126)

A new map shows that Angkor, the world's largest preindustrial city, covered more than 1,000 square kilometers of what is now Cambodia and possessed an elaborate canal system. (p. 126)

A vaccine for ovarian cancer enables some women who've undergone chemotherapy to stay in remission. (p. 126)

Measurements of the speed with which heat travels along single hydrocarbon molecules could aid in the design of molecular electronics. (p. 126)

(p. 127)