Samburu tribesmen stand during the Maralal Camel Derby, Kenya, August 15, 2015. Maralal, a small, arid town about an eight-hour drive north of the Kenyan capital Nairobi, holds an annual camel festival, bringing together members of the Samburu, Turkana and Pokot semi-nomadic cattle-herding tribes. (Photo by Goran Tomasevic/Reuters)

Erica Bougard of the U.S. competes in the high jump event of the women's heptathlon during the 15th IAAF World Championships at the National Stadium in Beijing, China, August 22, 2015. (Photo by Fabrizio Bensch/Reuters)

Genzebe Dibaba of Ethiopia competes in the women's 1500m semi-final during the 15th IAAF World Championships at the National Stadium in Beijing, China August 23, 2015. (Photo by Lucy Nicholson/Reuters)

Revelers march in the Lower Ninth Ward during a second line parade marking the 10th anniversary of Hurricane Katrina on August 29, 2015 in New Orleans, Louisiana. (Photo by Mario Tama/Getty Images)

Shell, which is the replica of the biggest detonated Soviet nuclear bomb AN-602 (Tsar-Bomb), is on display in Moscow, Russia, August 31, 2015. The shell is part of an exhibition organized by the state nuclear corporation Rosatom. (Photo by Maxim Zmeyev/Reuters)

A woman rows her boat as she harvests tomatoes on Inle lake, in Myanmar's Shan State September 4, 2015. Inle is one of the country's most popular tourist sites. (Photo by Soe Zeya Tun/Reuters)

A cook grills chicken during the Festival des Grillades, in the yard of the Culture Palace of Abidjan, September 5, 2015. The two day festival was iniated in 2008 to promote Ivorian cuisine, which revolves around grilled food. (Photo by Luc Gnago/Reuters)

A machine assembles powder, cartridges and bullets tips together to make 300 AAC Blackouts at Barnes Bullets in Mona, Utah, January 6, 2015. (Photo by George Frey/Reuters)