UAB (University of Alabama at Birmingham) researchers have developed a method to increase bone density in mice, a development that might have future benefit for humans in the treatment of osteoporosis and bone fracture. The research, published in the Jan. 29 issue of Proceedings of the National Academy of Sciences, involves manipulation of the Pten gene, which contributes to the process by which cells die, known as apoptosis.

"Bone density can increase either because more bone cells divide or fewer cells die due to apoptosis. Pten is a tumor suppressor gene that applies a break on the main cell survival pathway, causing cells to die," said Thomas L.

In an advance that could lead to composite materials with virtually limitless performance capabilities, a University of Wisconsin-Madison scientist has dispelled a 50-year-old theoretical notion that composite materials must be made only of "stable" individual materials to be stable overall.

Writing in the Feb. 2 issue of the journal Physical Review Letters, Engineering Physics Professor Walter Drugan proves that a composite material can be stable overall even if it contains a material having a negative stiffness, or one unstable by itself-as long as it is contained within another material that is sufficiently stable.

For the first time, scientists have observed DNA being damaged by ultraviolet (UV) light.

Ohio State University chemists and their colleagues in Germany used a special technique to watch strands of DNA in the laboratory sustain damage in real time.

They observed the most common chemical reaction among a family of reactions on the DNA molecule that are linked to sunburn, and discovered that this key reaction happens with astounding speed -- in less than one picosecond, or one millionth of one millionth of a second.

Scientists have long struggled to figure out how the brain guides the complex movement of our limbs, from the graceful leaps of ballerinas to the simple, everyday act of picking up a cup of coffee. Using tools from robotics and neuroscience, two Johns Hopkins University researchers have found some tantalizing clues in an unlikely mode of motion: the undulations of tropical fish.

Malaria kills more than one million people each year, most of them young children living in Africa. Now physicists in the UK have shared their computers with biologists from countries including France and Korea in an effort to combat the disease.

Using an international computing Grid spanning 27 countries, scientists on the WISDOM project analysed an average of 80,000 possible drug compounds against malaria every hour. In total, the challenge processed over 140 million compounds, with a UK physics Grid providing nearly half of the computing hours used.

The computers are all part of EGEE (Enabling Grids for E-sciencE), which brings together computing Grids from different countries and disciplines.

Groundhogs and other hibernators take a very sensible approach to winter: They slip into a state of suspended animation and let the worst of the cold weather pass.

The cold prompts profound physiological changes in these animals, causing their normally fast metabolism to come almost to a stop during winter. With metabolism slowed to a crawl, the animal draws on its fat stores sparingly to make it through the winter.

Hibernation has become the focus of interesting physiological research. A hibernating squirrel's heart may fall from 300 beats per minute to just three per minute. Its oxygen consumption can drop to just 2% of normal.