A woman receives the rVSV-ZEBOV Ebola vaccine at a clinical trial in Conakry, Guinea. The vaccine appears effective after only one shot. Cellou Binani/AFP/Getty Images hide caption

itoggle caption Cellou Binani/AFP/Getty Images

A Marine Corps F-35B Joint Strike Fighter does a short takeoff (STOVL) from Patuxent River Naval Air Station, Md., in 2011. Eighteen years after development began, a version of the plane designed for the Marine Corps is expected to be deemed "combat ready." Cliff Owen/AP hide caption

itoggle caption Cliff Owen/AP

Using a digital device that displays Braille characters, Haben Girma talks with President Obama at a White House ceremony marking the 25th anniversary of the Americans with Disabilities Act. White House photo/Courtesy of Haben Girma hide caption

itoggle caption White House photo/Courtesy of Haben Girma

In this image taken from a November 2012 video, Cecil the lion is shown in Hwange National Park in Zimbabwe. Paula French via AP hide caption

itoggle caption Paula French via AP