A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

A stranded cat swims through flood water searching for dry land June 16, 2008 in Oakville, Iowa. (Photo by Scott Olson/Getty Images)

“Hatem Moussa joined The Associated Press as a photojournalist in 1998. Since then, the Gaza City-based Moussa has covered repeated rounds of Israeli-Palestinian fighting in Gaza, including the wars of 2008-9, 2012 and 2014”. – Associated Press. Photo: A Palestinian youth jumps into the Mediterranean sea on the beach at the port of Gaza City, Gaza, Monday, August 27, 2012. (Photo by Hatem Moussa/AP Photo)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

A rickshaw driver looks out the windshield as he drives onto the highway in Mardan, Pakistan January 30, 2017. (Photo by Fayaz Aziz/Reuters)

Orin Larsen of Inglis, Manitoba hangs on to the horse Dancing Queen in the Bareback event during the Calgary Stampede rodeo in Calgary, Alberta, July 10, 2015. (Photo by Todd Korol/Reuters)

Developed for the British American Ambulance Corps, this new motorcycle ambulance is capable of speeding wounded soldiers 90 miles an hour from the front lines to field hospitals. Its springs are synchronized with the patient's heartbeat to avoid increasing fever when traveling over various Terrain. Viewing it in New York August 27, 1941, are left to right: constable Herbert Scott of England, driver; William E. Detlor, whose firm developed the vehicle; M. W. Stand, inspector-general of Civilian Defense, and Maj. Edward Riekert, also. (Photo by AP Photo)

Thousands gather to rally for marriage equality ahead of a national postal survey on September 10, 2017 in Sydney, Australia. The High Court handed down its decision on Thursday to allow the government's proposed postal ballot survey to go ahead. Ballots with the question “Should the law be changed to allow same-sеx couples to marry?” will be sent to households across Australia on September 12. (Photo by Jonny Weeks/The Guardian)