In pursuing cleaner energy there is such a thing as being too green. Unicellular microalgae, for instance, can be considered too green. In a paper in a special energy issue of Optics Express, the Optical Society's (OSA) open-access journal, scientists at the University of California, Berkeley describe a method for using microalgae for making biofuel. The researchers explain a way to genetically modify the tiny organisms, so as to minimize the number of chlorophyll molecules needed to harvest light without compromising the photosynthesis process in the cells. With this modification, instead of making more sugar molecules, the microalgae could be producing hydrogen or hydrocarbons.

Hundreds of trillions of bacteria make their home in the vertebrate gut. Though many of these microbes perform helpful duties for their host, others—the pathogens—are unwelcome visitors, causing disease.

A new U.S. study has found that being circumcised significantly reduced the risk of HIV infection in heterosexual African American men known to have been exposed to the virus. The findings complement those of recently reported clinical trials in Africa, where interventional use of adult male circumcision similarly reduced the risk of HIV infection in heterosexual men. The findings of the new study, along with similar results from other studies, suggest that circumcision may protect other heterosexual males in the U.S. The promising new findings are reported in the January 1 issue of The Journal of Infectious Diseases, now available online.

Purdue University researchers found a mechanism that naturally shuts down cellulose production in plants, and learning how to keep that switch turned on may be key to enhancing biomass production for plant-based biofuels.

University of Minnesota anthropology professor Kieran McNulty (along with colleague Karen Baab of Stony Brook University in New York) has made an important contribution toward solving one of the greatest paleoanthropological mysteries in recent history -- that fossilized skeletons resembling a mythical "hobbit" creature represent an entirely new species in humanity's evolutionary chain.

Los Angeles, CA – December 17, 2008 – A new study in the journal Personal Relationships reveals that women prefer mates who are recognized by their peers for their skills, abilities, and achievements, while not preferring men who use coercive tactics to subordinate their rivals. Indeed, women found dominance strategies of the latter type to be attractive primarily when men used them in the context of male-male athletic competitions.

Researchers at the University of Rochester have designed a gene that produces a thousand times more protein in cancer cells than in healthy cells.