Drylands, where 38 percent of the world's population lives, can be protected from the irreversible damage of desertification if local residents and managers at all levels would follow basic sustainability principles, according to a panel of experts writing in the May 11 issue of the journal Science.

The study makes a point of introducing hope rather than the usual gloom, said James Reynolds of Duke University, who is the first author. "(Given) recent advances in dryland development, concerns about land degradation, poverty, safeguarding biodiversity and protecting the culture of 2.5 billion people can be confronted with renewed optimism," the report said.

When male primates tussle and females develop their social skills it leaves a permanent mark – on their brains. According to research published in the online open access journal BMC Biology, brain structures have developed due to different pressures on males and females to keep up with social or competitive demands.

An international research team consisting of Patrik Lindenfors, Charles Nunn and Robert Barton examined data on primate brain structures in relation to traits important for male competition, such as greater body mass and larger canine teeth.

Researchers have uncovered a large area of low but increasing gravity over North America – the lingering effect of the last ice age when sheets of ice sometimes three kilometres thick covered nearly all of Canada and the northeastern U.S.

The study is the first to show a map of ongoing changes in the gravity field over North America due to the ice age. It provides an unprecedented image of the geometry of the long-vanished Laurentide ice sheet: a massive ice complex that had two major domes, one east and the other west of the Hudson Bay area, and raised global sea-level about 60 metres when it disappeared.

Does sex education promote sex among children or discourage it? What about drug campaigns?

"Research on attitude formation has increasingly recognized that attitudes can be comprised of separate negative and positive components which can result in attitude ambivalence," explain Gavin Fitzsimons (Duke University), Joseph C. Nunes (University of Southern California), and Patti Williams (University of Pennsylvania). "In the present research we focus on vice behaviors, those for which consumers are likely to hold both positive and negative attitudes.

Many products, such as golf clubs or cameras, are designed for consumers of a certain skill level. However, deciding what product would be most appropriate is often based on skewed self-assessment, leading to a purchase of equipment that may be too advanced or too basic. A revealing new study from the June issue of the Journal of Consumer Research shows how these choices may be affected by marketing strategies and provides insight into how consumers can better select the right products for their particular skill level.

Perceptions of skill are frequently inaccurate because people base assessments of their own ability on how hard the task feels – rather than more objective criteria like what percentage of the population is able to perform the same task, explains Katherine A.

Researchers have created the first computational model to track engine performance from one combustion cycle to the next for a new type of engine that could dramatically reduce oil consumption and the emission of global-warming pollutants.

"We're talking about a major leap in engine technology that could be used in hybrid cars to make vehicles much more environmentally friendly and fuel stingy," said Gregory M. Shaver, an assistant professor of mechanical engineering at Purdue University.