A female Kurdistan Workers Party (PKK) fighter works on her laptop while watching a Kurdish TV station at a base in the Sinjar mountains, March 11, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih/Reuters)

Comandos de Salvamento rescuers Maria Martinez (L) and Ana Chichilla attend to a wounded homeless man in San Salvador, El Salvador July 16, 2016. The man was attacked with a machete by suspected gang members. In 2015, El Salvador registered a record 103 homicides per 100,000 habitants, making it one of the most dangerous countries in the world outside a war zone. But for many young people who have few chances to distance themselves from rivalries between so-called maras in their schools and neighbourhoods, a civil-society organisation called the Comandos de Salvamento, or Rescue Corps, has been a refuge. (Photo by Jose Cabezas/Reuters)

Female metro passengers hold flowers presented to them by metro workers, prior to International Women's Day in Kiev, Ukraine, 02 March 2016. The hustle and bustle of the morning commute is broken up by an unexpected surprise. The first passengers to step on the train receive – a warm welcome and a pot of flowers. One woman says, “It's very nice. All the running around and then you're given a flower, it's not often. It's very nice. I'm going to take care of this flower”. International Women's Day first emerged from the activities of labour movements at the turn of the twentieth century, in North America and across Europe, it is celebrated on March 08 in many countries around the world. (Photo by Sergey Dolzhenko/EPA)

A camel foams at the mouth as he is whipped by a robot jockey during a race at Nad al-Sheba on December 6, 2006 in Dubai, United Arab Emirates. This is the first season that robotic jockeys have been used to race camels in Dubai. Controversially children from India were used to ride the camels in past seasons. These robot jockeys costing 15000GBP and up, were designed in Geneva and include shock absorbers and GPS tracking systems. The camel's owners control them from their speeding four wheel drives at the side of the track. (Photo by Chris Jackson/Getty Images)

A Sudanese man walks to a United Nations displacement camp after crossing into Tunisia from Libya on March 06, 2011 in Ras Jdir, Tunisia. As fighting continues in and around the Libyan capital of Tripoli, tens of thousands of guest workers from Egypt, Tunisia, Bangladesh and other countries are fleeing to the border of Tunisia to escape the violence. The situation has turned into a humanitarian emergency as fledgling Tunisia is overwhelmed with the workers. Libyan leader Muammar Gaddafi has vowed to fight to the end. (Photo by Spencer Platt/Getty Images). RAS JDIR, TUNISIA – MARCH 06 2011

Chinese Artist Ai Weiwei holds some seeds from his Unilever Installation “Sunflower Seeds” at The Tate Modern on October 11, 2010 in London, England. The sculptural installation comprises 100 million handmade porcelain replica sunflower seeds. (Photo by Peter Macdiarmid/Getty Images)

A man admires a sculpture in the series entitled 'Circle of Animals/Zodiac Heads' by Chinese artist Ai Weiwei in the courtyard of Somerset House on May 11, 2011 in London, England. The installation comprises of 12 bronze heads of animals which feature in the Chinese zodiac. The artist Ai Weiwei, who is outspoken in his criticism of the Chinese administration, was detained by authorities in Beijing on April 3, 2011 and his whereabouts remain unknown.

A new LED light fixture is secured to the side of a lift as crews replace existing street lights August 1, 2011 in Las Vegas, Nevada. The new energy-efficient fixtures are expected to reduce the city's annual electricity use by eight million kilowatt hours, saving about USD 400,000. The city estimates the LEDs will last about 15 years, nine years longer than the current lights. Funding for the project comes from federal energy conservation bonds and an American Recovery & Reinvestment Act grant. The city plans to replace all of its 50,000 streetlights after more funding is secured. (Photo by Ethan Miller/Getty Images)