A Western bluebird fledgling, color-banded at UC Berkeley's Hastings Reserve in Carmel Valley. (Copyright 2004 by Neil Losin)Parents whose grown children have not yet flown the nest can only sympathize with the Western bluebird. While female fledglings fly off on their own in late summer, their brothers typically hang around through the winter and into the next breeding season, living off the bounty of their parents' larder.

Credit: Jeff Stevens.Across the animal kingdom, individuals face choices between patience and impulsivity. A classic case, confronted by all animals--humans included--is that between a small, immediate food reward and a delayed, but larger, reward. In such cases, impulsivity typically trumps patience as individuals fail to delay gratification. But what factors influence these decisions? Researchers have gained new insight into this question by showing that the particular ways in which animals exhibit patience and impulsivity differ from one context to another and may be closely related to the animals' ecological niches and their everyday interactions with the natural world.

The peer-reviewed results of the first trial of the effect of male circumcision on HIV infection, which some experts call "a landmark trial," will be published in PLoS Medicine on October 25. The trial found that circumcision reduced the rate of new infections among heterosexual men in South Africa by about 60%.

UCSD scientists have gained a better understanding of how repetitive stretching of endothelial cells that line arteries can make them healthy and resistant to vascular diseases.

UCSD researchers stretched cells in a workout chamber the size of a credit card to gain a better understanding of how repetitive stretching of endothelial cells that line arteries can make them healthy and resistant to vascular diseases.

Seafood prices collected from U.S. restaurant menus dating to the 1850s will help plot the shifting harvest of marine species, according to a study to be announced at Oceans Past a Census of Marine Life conference in Denmark on the History of Marine Animal Populations.

CHAPEL HILL – An enzyme inside a bacterium that grows in the soil of potato fields can -- in a split second -- break down residues of a common powerful pesticide used for killing worms on potatoes, researchers have found.

New classification conveys important information about the biochemistry and metabolism of disease-causing organisms. The new classification recognizes 6 major clusters of organisms, rather than the 4 traditional Kingdoms.

Many baffled parents have wondered whether their teenagers would ever stop growing. The answer is obvious, but researchers have never really quite understood just how an organism determines when it has reached its optimal size and growth should cease.