Third-year medical student Allie Tetreault, left, talks with Gabrielle Nuki, 16, at Maine Medical Center in Portland, Maine. Gabrielle helps med students practice patient care. Patti Wight/MPBN hide caption

itoggle caption Patti Wight/MPBN

A still from the surveillance camera footage shows the fainting man (top left and bottom right) lying alone in a subway car, as the few remaining occupants hurry away. YouTube hide caption

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Russian Foreign Minister Sergei Lavrov called Monday for a cease-fire in Ukraine, but demanded that Ukrainian troops leave positions from which they can "harm the civilian population." His comments come ahead of talks in Minsk, Belarus, involving Ukraine, Russia, Russia-backed separatists and international monitors. Jia Yuchen/Xinhua /Landov hide caption

itoggle caption Jia Yuchen/Xinhua /Landov

Tony Stewart, driver of the #14 Bass Pro Shops / Mobil 1 Chevrolet, hits the wall on the backstretch during the NASCAR Sprint Cup Series Oral-B USA 500 at Atlanta Motor Speedway on Sunday in Hampton, Ga. Jamie Squire/Getty Images hide caption

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A recent study found a brief delay in peak growth spurt among boys who took ADHD stimulants for at least three years, but no significant effect on their ultimate height. iStockphoto hide caption

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Nancy Becker, an Amazon employee in Bad Hersfeld, Germany, speaks at a protest rally outside the company's headquarters in Seattle in December. Ted S. Warren/AP hide caption

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Kwei Quartey sets one of the crime scenes in his second D.I. Dawson book in Agbogbloshie, an Accra slum. Ofeibea Quist-Arcton /NPR hide caption

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Jason Wright, seen here during his 15-month deployment to Iraq, served in the military for nine years before resigning last week. Courtesy of Jason Wright hide caption

itoggle caption Courtesy of Jason Wright

Across Washington State, hydroelectric dams are blocking salmon as they migrate to their spawning grounds. Enter the salmon cannon. Ingrid Taylar/Flickr hide caption

itoggle caption Ingrid Taylar/Flickr

(Left) A woman holds the saffron crocus, during the saffron harvest in Herat, Afghanistan. (Right) Saffron flowers are collected in Saint Hippolyte, eastern France. Since the stigmas need to be picked from the flowers by hand, saffron is the world's most expensive spice. Majid Saeedi/Getty Images; Maxppp /Landov hide caption

itoggle caption Majid Saeedi/Getty Images; Maxppp /Landov

Martha (right), an extinct passenger pigeon, at the Smithsonian's Natural history Museum in Washington. The passenger pigeon was once the world's most plentiful bird. Sept. 1 is the centenary of the bird's extinction. Susan Walsh/AP hide caption

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Lindolfo Carballo, an immigrant from El Salvador, meets his son Raynel outside school. In El Salvador, he says, families often "teach their boys one thing and their girls differently." He's trying to set a different example for his children. Sarah Tilotta for NPR hide caption

itoggle caption Sarah Tilotta for NPR