A kidney donor is wheeled to an operating room for a transplant at Johns Hopkins Hospital in Baltimore in late June. Brendan Smialowski/AFP/Getty Images hide caption

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Two men from northwestern Missouri became ill after tick bites infected them with a previously unknown virus. iStockphoto.com hide caption

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A Beechcraft airplane sprays insecticide over Dallas early Monday morning to curb the spread of West Nile virus. LM Otero/AP hide caption

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People wait in line at the Durham County Health Department for the H1N1 flu vaccination in Durham, N.C., in November 2009. Gerry Broome/AP hide caption

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Older women on a diet don't need to stop eating out; they just may need to make wiser food choices to keep weight off. iStockphoto.com hide caption

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Though scientists have identified sleepwalking triggers, the condition is still a bit of a mystery. Victoria Alexandrova/iStockphoto.com hide caption

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Social worker Shannon Coyne and her husband decided against circumcision for their son, now 11 months old. The nation's most influential pediatricians group says the health benefits of circumcision in newborn boys outweigh any risks and that insurance companies should pay for it. Matt Rourke/AP hide caption

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A PET scan of the brain of a person with Alzheimer's disease. U.S. National Institute on Aging/Wikimedia Commons hide caption

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Ashley Beecher, 29, and her daughters Annie (on lap) and Charlie. After feeding Annie, Beecher donates her extra supply to the human milk bank at Texas Children's Hospital. KUHF hide caption

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