People on motor bikes celebrate American President Barack Obama's visit to Kenya by holding up a photo, center top, of the president and First Lady Michelle Obama in Kisumu, Kenya, Saturday, July 25, 2015. President Barack Obama heralded Africa as a continent “on the move” Saturday as he opened a U.S.-sponsored business summit in Kenya, the East African nation where he has deep family ties. (Photo by AP Photo)

Revelers dance during the “Ceu na Terra”, or Heaven on earth, carnival parade in Rio de Janeiro, Brazil, Saturday, February 7, 2015. Rio's over-the-top Carnival is the highlight of the year for many local residents. Hundreds of thousands of merrymakers are beginning to take to the streets in open-air “blocos” parties. (Photo by Felipe Dana/AP Photo)

In this Thursday, February 19, 2015 photo, participants at a seminar on edible insects taste a Cricket Consomme at Le Cordon Bleu cooking school in Bangkok, Thailand. A group of chefs and food scientists at the esteemed French school's branch in Bangkok spent the week simmering, sautéing and grilling insects to extract innovative flavors they say could open a new frontier for the world of gastronomy. (Photo by Sakchai Lalit/AP Photo)

Riot Police form a cordon as a Police car burns on the opening day of the European Central Bank (ECB) in Frankfurt am Main, western Germany, on March 18, 2015. Supporters of the so-called Blockupy alliance consisting of social movements, activists, workers, trade unions and parties are expected to stage large protests against austerity and the authority of the European Central Bank when the bank's new headquarters officially will be on March 18, 2015. (Photo by Odd Andersen/AFP Photo)

In this March 18, 2015 photo, Andrea, better known as Loira, which is the Portuguese word for “blonde”, poses for a portrait in an open-air crack cocaine market, known as a “cracolandia” or crackland where users can buy crack, and smoke it in plain sight, day or night, in Rio de Janeiro, Brazil. Andrea says she is married and has a home, but she keeps returning to crackland to feed her addiction. (Photo by Felipe Dana/AP Photo)

An elephant mahout (trainer) lies on his elephant his feet resting on its ears as it rests and eats prior to opening day's play at the King's Cup Elephant Polo Tournament 2014 held near Bangkok, in Samut Prakan province, Thailand, 28 August 2014. The annual charity tournament runs until 31 August and involves 51 elephants who normally live on the streets and are used for begging. Sixteen competing elephant polo teams from 40 different nations take part in the charity event directed at raising funds to improve the lives of the elephants and elephant conservation in general. (Photo by Barbara Walton/EPA)

Members of the U.S. Army 173rd Airborne Brigade stand at attention as a Ukrainian folk dance group performs at the opening ceremony of the “Rapid Trident” NATO military exercises on September 15, 2014 near Yavorov, Ukraine. The two-week exercises include participating units from a variety of NATO and NATO-associate countries as well as Ukrainian troops. Meanwhile fighting between pro-Russian separatists and Ukrainian armed foces has flared again in eastern Ukraine in a battle for the control of Donetsk airport despite the tenuous ceasefire. (Photo by Sean Gallup/Getty Images)

A resident looks into a newly-built giant trash can, partially buried underground, next to a street in Taiyuan, Shanxi province November 6, 2014. The trash can, which has a diameter of 1.9 meters and a depth of 2.8 meters, could contain approximately 10 cubic metres of garbage. It was built to replace an open-air garbage dump site, local media reported. (Photo by Reuters/Stringer)