A sign is posted in front of the new Yoga Room at San Francisco International Airport's terminal two on January 26, 2012 in San Francisco, California. (Photo by Justin Sullivan/Getty Images)

Twin baby panthers Remaong and Ferra cling to their basket while being presented to the media at Tierpark Berlin zoo on July 13, 2012 in Berlin, Germany. The two panthers were born in captivity on April 26. (Photo by Sean Gallup)

A love story with two log choppers. “In 1993, I was working on a project about life in the Olomouc region of Czechoslovakia. One day, I came to the village of Dlouhá Loučka-Křivá and went into a courtyard where I saw two old people, a husband and wife, sawing firewood for winter. They were working quietly, concentrating. I watched them fetch a beam from a wrecked barn, but they didn’t discuss how they planned to carry it to the saw. The woman faced one way, the man the other. When they realised, the woman eventually turned and followed her husband. The picture I took is the picture of many relationships – when each partner wants something different, but they have to come to an agreement, pull together eventually”. (Photo by Jindrich Streit)

Revelers participate in the traditional Bloco da Lama (Mud block) carnival in Parati, Rio de Janeiro State, Brazil, on February 9, 2013. The event, which was begun by two men in a playful manner in 1986, has now become a traditional carnival in which participants disguised as primitives with rags, lianas or skulls and bones, dive in the mud. (Photo by Victor Moriyama/AFP Photo)

An infrared portrait from NASA's Spitzer Space Telescope which shows generations of stars is seen in this undated NASA handout image released February 14, 2013. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Red shows heated dust that pervades the region's cavities, while green highlights dense clouds. (Photo by NASA/Reuters/JPL-Caltech/Harvard-Smithsonian/Handout)

Dan McManus and his service dog Shadow hang glide together outside Salt Lake City, Utah, July 22, 2013. McManus suffers from anxiety and Shadow's presence and companionship help him to manage the symptoms. The two have been flying together for about nine years with a specially made harness for Shadow. (Photo by Jim Urquhart/Reuters)