These pop-up targets are part of an advanced drill, named "friend or foe," that tests shooter reaction times. Some targets have a camera, and others, like these pictured, have a gun. The shooter must decide within seconds whether to shoot.
Silvester Fullard fixes dinner for his 11-year-old son Tavestsiar. When Tavestsiar first came to live with his dad in 2010, he was closed off, Silvester says; "he didn't want to be around other kids."
Charles Mostoller for NPR
U.N. Secretary-General Ban Ki-Moon (in white-and-blue vest) joins other leaders at the 2015 International Women's Day March at Dag Hammarskjold Plaza on March 8 in New York City.
Michael Stewart/WireImage/Getty Images
Prion protein can be infectious, spreading from cell to cell in the brain. Here four nerve cells in a mouse illustrate how infectious prion protein moves within cells along neurites — wire-like connections the nerve cells use for communicating with adjacent cells.
The new doughnut-shaped building will be a mile in circumference. "The office areas are laid out in little wedges all around the building," says Dan Whisenhunt, Apple's vice president of real estate and development.