Television trucks converged on Mount Sinai Hospital in New York on Monday after it announced that it was screening a patient for Ebola virus. Stan Honda/AFP/Getty Images hide caption

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A member of Doctors Without Borders dons protective gear in Conakry, Guinea. U.S. health care workers will use similar protective garb. Cellou Binani/AFP/Getty Images hide caption

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Truvada has been around for a decade as a treatment for people who are already HIV-positive. In the last few years, it has also been shown to prevent new infections, and New York officials are embracing the pill as a way to prevent the spread of AIDS. Justin Sullivan/Getty Images hide caption

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

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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

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

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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

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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

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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

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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

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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

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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

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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

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Mourners attend a memorial service for recent cholera victims in Haiti that took place Wednesday in Savanette, an isolated community in the mountains outside Mirebalais, Haiti. Cate Oswald/Partners in Health hide caption

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