Selenium is a trace element crucial to life - too little or too much of it is fatal. In the July 17 issue of the journal Science, researchers at Yale University and University of Illinois at Chicago detail the molecular mechanisms that govern its metabolism in the human body.

There she is again: the cute girl at the mall. Big eyes. Long legs. She smiles at you. You're about to make your move… but wait! What's she wearing? It's a letterman jacket, one clearly belonging to a hulking football player named "Steve." This girl is taken. Wisely, you move on.

A single evolutionary event appears to explain the short, curved legs that characterize all of today's dachshunds, corgis, basset hounds and at least 16 other breeds of dogs, a team led by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, reported today. In addition to what it reveals about short-legged dogs, the unexpected discovery provides new clues about how physical differences may arise within species and suggests new approaches to understanding a form of human dwarfism.

New vaccines have the potential to prevent or temper epidemics of the childhood diarrhea-causing disease rotavirus, protect the unvaccinated and raise the age at which the infection first appears in children, federal researchers reported in a study today.

Researchers at Georgia State University have found that diets high in fructose — a type of sugar found in most processed foods and beverages — impaired the spatial memory of adult rats.