A military police officer patrols in the Roquette Pinto shantytown, part of the Mare slum complex in Rio de Janeiro, Brazil, Wednesday, April 1, 2015. The Brazilian army has begun to pull out of one of Rio de Janeiro's most violent slums, with police assuming responsibility for security in the area. (Photo by Felipe Dana/AP Photo)

In this Friday, January 9, 2015 photo, bathhouse worker Omid Riahi, 39, scrubs a man to remove dead skin, at the Ghebleh public bathhouse, in Tehran, Iran. The steamy air and curved tiled walls of Iran's famed public bathhouses, some rinsing and massaging patrons for hundreds of years, slowly may wash away as interest in them wanes. The bathhouses, known as “hammams” in Persian, find themselves in rough financial times as modern conveniences now allow showers and baths in most homes across the Islamic Republic. (Photo by Ebrahim Noroozi/AP Photo)

Pilgrims dressed in traditional Bavarian clothes attend the traditional Georgi horse riding procession on Easter Monday in heavy snowfall, in the southern Bavarian town of Traunstein April 6, 2015. Since the early 16th century, farmers have taken part in the pilgrimage to bless their horses. This tradition, the “Georgiritt”, goes back to the legend of Saint George, the horsemen's patron saint. (Photo by Michael Dalder/Reuters)

A freighter trapped in ice is shown in this aerial photo near Whitefish Bay on Lake Superior northwest of Sault Ste. Marie, Ontario April 7, 2015. The biggest ice cover on the Great Lakes in decades is backing up shipments of everything from Canadian grain to U.S. iron and steel in one of North America's most important economic regions. (Photo by Kenneth Armstrong/Reuters)

In this photo released by Xhinhua News Agency, a rescuer evacuates residents near the site of a chemical plant blast in Zhangzhou, southeast China's Fujian Province Tuesday, April 7, 2015. Six people have been hospitalized and hundreds of firefighters deployed to battle a blaze sparked by an explosion at Goure PX Plant that produces the toxic chemical paraxylene, officials said Tuesday. (Photo by Wei Peiquan/AP Photo/Xinhua)

A lady-in-waiting adjusts the dress and Christian Louboutin shoes of Dayangku Raabi'atul 'Adawiyyah Pengiran Haji Bolkiah as Adawiyyah waits for Prince Abdul Malik to arrive for the “bersanding” or enthronement ceremony at their wedding in the Nurul Iman Palace in Bandar Seri Begawan April 12, 2015. Malik is the son of Brunei's Sultan Hassanal Bolkiah, one of the world's richest men. (Photo by Olivia Harris/Reuters)

Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

A humanoid robot named Kansei, meaning “sensibility” in Japanese, makes a facial expression depicting “happiness”, next to the word “Love” during a demonstration at a laboratory of Meiji University's Robot and Science Institute in Kawasaki, south of Tokyo in this June 4, 2007 file photo. Three-fourths of robot installations over the next decade are expected to be concentrated in four areas: transportation equipment, including the automotive sector; computer and electronic products; electrical equipment and machinery. Labor costs have climbed in countries such as China that have been popular for outsourcing production, while technological advances for robots allow them to be more flexible and perform more tasks. (Photo by Yuriko Nakao/Reuters)