Small but costly: Dozens of mosquito species carry West Nile virus in the U.S. Darren McCollester/Getty Images hide caption

itoggle caption Darren McCollester/Getty Images

An ambulance makes its way through revelers in Cardiff city center in Wales in 2010. New measures in the city have reduced injuries caused by violence. Matt Cardy/Getty Images hide caption

itoggle caption Matt Cardy/Getty Images

Differences in brain chemistry can affect an individual's likelihood of weight gain. Katherine Streeter for NPR hide caption

itoggle caption Katherine Streeter for NPR

A Thai medic checks bodies for forensic identity in Phang Nga province in southern of Thailand on Jan. 11, 2005. Thousands of people were killed in Thailand after a massive tsunami struck on Dec. 26, 2004. Pornchai Kittiwongsakul/AFP/Getty Images hide caption

itoggle caption Pornchai Kittiwongsakul/AFP/Getty Images

Michelle Williams (center) and two daughters visit the grave of her mother, Judy Williams, at Fairview Cemetery in Hyde Park, Mass., on May 11. Judy died in 2011. Ellen Webber for NPR hide caption

itoggle caption Ellen Webber for NPR

Most people polled in a new survey said government programs to make fresh fruits and vegetables more affordable sound like a great idea. iStockphoto.com hide caption

itoggle caption iStockphoto.com

PepsiCo's product line ranges from salty chips and its sugary namesake drink to more healthful fare like hummus and yogurt. In 2010, the company announced plans to cut sugar, fat and sodium in its products to address health and nutrition concerns. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

People line up at a Duane Reade pharmacy in New York behind a sign announcing the recent flu outbreak. Andrew Kelly/Reuters/Landov hide caption

itoggle caption Andrew Kelly/Reuters/Landov

San Juan Creek meets the Pacific Ocean at Doheny State Beach in Dana Point, Calif. The poor water quality off Doheny State Beach put in a list of worst beaches in the U.S. Reed Saxon/AP hide caption

itoggle caption Reed Saxon/AP

A fireman walks amongst the rubble and the smoldering wreckage of the World Trade Center in New York in the wake of the Sept. 11, 2001, attacks. Gary Friedman/AFP/Getty Images hide caption

itoggle caption Gary Friedman/AFP/Getty Images