A nanosecond pulsed laser beam starts the photoacoustic imaging process. Geoff Story/Courtesy of Washington University in St. Louis hide caption

itoggle caption Geoff Story/Courtesy of Washington University in St. Louis

Transgender performers walk backstage during an event to mark World AIDS Day in 2013. A new WHO report demonstrates extremely rates of HIV infection among transgender women in 15 countries. Prakash Mathema/AFP/Getty Images hide caption

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Despite losing his sense of taste and smell to Alzheimer's disease, Greg O'Brien says grilling supper on the back deck with his son on a summer evening is still fun. Sam Broun/Courtesy of Greg O'Brien hide caption

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Christy O'Donnell, who has advanced lung cancer, is one of several California patients suing for the right to get a doctor's help with prescription medicine to end their own lives if and when they feel that's necessary. YouTube hide caption

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At the State Department conference for people with disabilities, adviser Judy Heumann (center) is surrounded by admirers from around the world. Joseph Shapiro/NPR hide caption

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