A protein known as the "master watchman of the genome" for its ability to guard against cancer-causing DNA damage has been found to provide an entirely different level of cancer protection: By prompting the skin to tan in response to ultraviolet light from the sun, it deters the development of melanoma skin cancer, the fastest-increasing form of cancer in the world.

In a study in the March 9 issue of the journal Cell, researchers at Dana-Farber Cancer Institute report that the protein, p53, is not only linked to skin tanning, but also may play a role in people's seemingly universal desire to be in the sun – an activity that, by promoting tanning, can reduce one's risk of melanoma.

Patients admitted to hospitals for ischemic stroke on weekends had a higher risk of dying than patients admitted during the week, in a Canadian study published in Stroke: Journal of the American Heart Association.

A "weekend effect" has been previously documented when looking at other conditions such as cancer and pulmonary embolism; however, little is known of its impact on stroke death.

"What is really novel in our work beyond the discovery of the 'weekend effect' on ischemic stroke is the subgroup analysis in other settings/characteristics and the identification of variables associated with the 'weekend effect,'" said Gustavo Saposnik, M.D., M.Sc., lead author of the study.

Two new studies by University of California, Berkeley, scientists highlight the amazing promiscuity of genes, which appear to shuttle frequently between organisms, especially more primitive organisms, and often in packs.

Such gene flow, dubbed horizontal gene transfer, has been seen frequently in bacteria, allowing pathogenic bacteria, for example, to share genes conferring resistance to a drug. Recently, two different species of plants were shown to share genes as well.

A new understanding of how plants manage their internal calcium levels could potentially lead to genetically engineering plants to avoid damage from acid rain, which robs soil of much of its calcium.

"Our findings should help scientists understand how plant ecosystems respond to soil calcium depletion and design appropriate strategies to protect the environment," said Zhen-Ming Pei, a Duke University assistant professor of biology who led the study, to be published in the Friday, March 9, issue of the journal Science.

The research was supported by the National Science Foundation, the U.S. Department of Agriculture and Xiamen University in China.

Calcium enters plants dissolved within the water that roots take in from surrounding soil.

How do female chimps make sure they only get the best mates? By never wanting to reproduce at the same time, insuring that none of them have to settle for less.

Female chimpanzees may have found a fool-proof way to ensure they mate with only the highest ranking males, namely those with important social and physical characteristics that their offspring may inherit, according to a new study by Akiko Matsumoto-Oda from the Department of Welfare and Culture at Okinawa University in Japan. Female chimpanzees do not synchronize their reproductive activities which reduces the opportunities for less-desirable males to coerce them into mating.

Something about normal, run-of-the-mill plants limits their reach upward. There's been no way to create that magical beanstalk in the fairy tales but no one knows why. For more than a century, scientists have tried to find out which part of the plant both drives and curbs growth: is it a shoot's outer waxy layer? Its inner layer studded with chloroplasts? Or the vascular system that moves nutrients and water? The answer could have great implications for modern agriculture, which desires a modern magical bean or two.

Now, in the March 8 issue of the journal Nature, researchers in the Plant Biology Laboratory at the Salk Institute for Biological Studies provide the answer.