Kenneth Bae, an American tour guide and missionary serving a 15-year sentence in North Korea, speaks to The Associated Press on Monday. Bae and two other detained Americans urged the U.S. to send a high-level emissary to secure their release. Wong Maye-E/AP hide caption

itoggle caption Wong Maye-E/AP

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

itoggle caption Susan Walsh/AP

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

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

itoggle caption iStockphoto

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