If the most popular foods of Rio de Janeiro have one thing in common, it is their informality. You can find fine restaurants in the city, but they do not set Rio apart from other places. What does set it apart, and what invariably brings its residents, known as "Cariocas," together is the unpretentious food they eat in bright, loud, crowded bars and restaurants, on busy street corners, or after a day at the beach. Here: A view of traditional bolinhos de bacalhau (fried codfish balls) in Rio de Janeiro, Brazil, May 7, 2016. (Photo by Sergio Moraes/Reuters)

An Alitalia plane approaches to land as starlings fly at Fiumicino international airport in Rome October 14, 2013. Italy will have to notify a planned government-led 500-million-euro bailout of near-bankrupt airline Alitalia to EU regulators who will then assess whether the measure complies with EU state aid rules, the European Commission said on Monday. (Photo by Max Rossi /Reuters)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

Football Soccer, England vs Wales, EURO 2016, Group B, Stade Bollaert-Delelis, Lens, France on June 16, 2016. Soccer fan Laura Woods from England fixes her makeup near riot police near the Lens stadium before the England vs Wales game. (Photo by Wolfgang Rattay/Reuters)

People watch as an acrobat rides his motorcycle around a circular track at an entertainment park set up outside a shrine in Rawalpindi, Pakistan, on June 19, 2013. (Photo by Muhammed Muheisen/Associated Press)

A woman, with her face covered with colored powders, dances during the Holi Festival of Colors in Lisbon, Sunday, September 15 2013. The festival, which is mainly celebrated during the Hindu spring festival Holi in some regions of India and Nepal, has become popular among people in other communities. (Photo by Francisco Seco/AP Photo)

Throughout the course of the long war in Afghanistan, Coalition troops have relied on thousands of military working dogs to help keep them safe, and make their jobs easier. The dogs are trained to detect explosives, to find illegal drugs, to search for missing comrades, or target enemy combatants. Not only are they active on the front lines, but behind the lines they serve as therapy dogs, service dogs, and loyal companions. They also share the same risks as the ground troops, suffering injuries and sometimes death on the battlefields. Gathered here are images of these dogs and their handlers in Afghanistan and back home, from over the past several years, part of the ongoing series here on Afghanistan.

Clown/comedian/filmmaker Pierre Etaix attends The Academy Of Motion Picture Arts And Sciences' Presents “Pierre Etaix: The Laughter Returns” at AMPAS Samuel Goldwyn Theater on November 16, 2011 in Beverly Hills, California. (Photo by Valerie Macon/Getty Images)