In the early years of the AIDS epidemic, being infected with the virus that causes the disease was considered a virtual death sentence. But with the development of antiretroviral therapy, many with HIV are now living much longer. In fact, it is estimated that by 2015, about half of all HIV-positive individuals will be older than 50.

ANN ARBOR, Mich. — A new study questions the controversial U.S. Preventative Service Task Force recommendations for breast cancer screening, with data that shows starting at a younger age and screening more frequently will result in more lives saved.

When it comes to breaking down plant matter and converting it to energy, the cow has it all figured out. Its digestive system allows it to eat more than 150 pounds of plant matter every day. Now researchers report that they have found dozens of previously unknown microbial enzymes in the bovine rumen – the cow's primary grass-digestion chamber – that contribute to the breakdown of switchgrass, a renewable biofuel energy source.