Two boys study together at a Chicago yeshiva in 2009. Public health officials say this type of close physical contact caused a mumps outbreak to spread throughout several orthodox Jewish communities in and around New York City. M. Spencer Green/AP hide caption

itoggle caption M. Spencer Green/AP

An image of researchers at Oregon Health & Science University removing the nucleus from the mother's cell before it's inserted into the donor's egg cell. Courtesty of Oregon Health & Science University hide caption

itoggle caption Courtesty of Oregon Health & Science University

Parents now have more advice to consider when it comes to choosing organic foods. Here, Theo Shriver, 6, weighs organic produce at the Puget Consumers Co-op in Seattle. Elaine Thompson/AP hide caption

itoggle caption Elaine Thompson/AP

Inglewood High School cheerleaders perform in front of the Space Shuttle Endeavour as it is transported through the streets of Inglewood and Los Angeles on October 13. ROBYN BECK/AFP/Getty Images hide caption

itoggle caption ROBYN BECK/AFP/Getty Images

Drinking diet soda and other low-calorie drinks may help you manage weight, but experts say plain old H2O is still the best way to go. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

A rabbi holds up a pillow used during ritual circumcision at a synagogue in Berlin. Markus Schreiber/AP hide caption

itoggle caption Markus Schreiber/AP

An 18-year-old girl winces as she has her third and final shot of the HPV vaccine. John Amis/AP hide caption

itoggle caption John Amis/AP