Researchers have shown that self-induced breaks in the DNA of immune cells known as lymphocytes activate genes that cause the cells to travel from where they're made to where they help the body fight invaders.

More than 330,000 lives were lost to HIV/AIDS in South Africa from 2000 and 2005 because a feasible and timely antiretroviral (ARV) treatment program was not implemented, assert researchers from the Harvard School of Public Health (HSPH) in a study published online by the Journal of Acquired Immune Deficiency Syndromes (JAIDS) (http://www.jaids.com/). In addition, an estimated 35,000 babies were born with HIV during that same period in the country because a feasible mother-to-child transmission prophylaxis program using nevirapine (an anti-AIDS drug) was not implemented, the authors write.

The Earth is in the midst of the sixth mass extinction of both plants and animals, with nearly 50 percent of all species disappearing, scientists say.

Fritz et al. have identified an amino acid switch that flaviviruses flip to gain access to cells.

Amyloid precursor protein (APP), whose cleavage product, amyloid-b (Ab), builds up into fibrous plaques in the brains of Alzheimer's disease patients, jumps from one specialized membrane microdomain to another to be cleaved, report Sakurai et al.

Melanoma patients infused with a special type of tumor-fighting T cell are more likely to survive without relapse, suggests a new study by researchers in France. Their report will be published online on October 20 in the Journal of Experimental Medicine.

The widespread use of pesticides across the United States has been in practice for decades, with little knowledge of the long-term effects on the nation's groundwater.