In this Wednesday, December 2, 2015 photo, Dr. Gal Kelmer, head of the department of large animals, unties a horse after its operation at the University's Koret School of Veterinary Medicine in Rishon Lezion, Israel. “Horses have an instinctive response of flight from danger”, Kelmer said. “The minute they wake up they start trying to stand and run, even if they don't have control of their limbs. So then they fall”. (Photo by Oded Balilty/AP Photo)

A Hypsiboas crepitans frog is pictured at a terrarium in Caracas November 30, 2015. Venezuelan frogs and toads are in critical danger due to climate change as rising temperatures complicate reproduction and spread a deadly fungus, say scientists, who liken the species to canaries in a coalmine warning of imminent danger. The survival of a group of nearly 20 frog and toad species, which top Venezuela's list of endangered species, may rest on a small group of academics in a Caracas laboratory attempting to recreate the amphibians' natural reproductive conditions. (Photo by Carlos Garcia Rawlins/Reuters)

An injured boy who is undergoing surgery, after he was injured in what activists said was an airstrike by forces loyal to Syria's president Bashar al-Assad, rests inside a field hospital in the Douma neighborhood of Damascus, Syria December 5, 2015. Douma in Syria, an area controlled by rebels fighting to topple President Bashar al-Assad, has been shelled continuously for the past three years. The injured are taken to basements and shelters transformed into field hospitals run by medical staff who have stayed in the battered neighbourhood of Damascus. (Photo by Bassam Khabieh/Reuters)

Models painted in camouflage colours to blend in with the background pose for Chinese artist Liu Bolin's artwork “Dongji”, or Winter Solstice, on the second day after China's capital Beijing issued its second ever “red alert” for air pollution, in Beijing, China, December 20, 2015. In this artwork, Liu wants to express his concerns about China and its people, including air pollution problem, Liu told Reuters. (Photo by Kim Kyung-Hoon/Reuters)

Ultra Orthodox Jews look at the body of an alleged Palestinian assailant in Jerusalem Saturday, December 26, 2015. According to a police spokeswoman, policemen approached a man who drew their suspicions just outside the Old City for following a pair of Jewish worshippers. Then he pulled out a knife and tried to stab one of them, officers opened fire and killed the assailant. (Photo by Mahmoud Illean/AP Photo)

Men wearing masks and dressed as military members take part in a festival honouring San Silvestre, in the town of Catarina, Nicaragua January 1, 2016. The placard reads, “I'm not afraid, young people off the streets, Ortega you sell our country”, in reference Nicaragua's President Daniel Ortega. (Photo by Oswaldo Rivas/Reuters)

A girl walks down the runway during a class at a modelling academy in Caracas, Venezuela, on September 20, 2014. Venezuela's famed models and aspiring beauty queens are struggling to doll themselves up. In a country that glorifies voluptuous women and opulent beauty pageants, even basics like deodorant are now at times tricky to find as strict currency controls have led to a scarcity of dollars for imported goods. (Photo by Carlos Garcia Rawlins/Reuters)

In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)