Members of the Public Safety System, the community police of Guerrero, hold weapons during night patrol, outside the Ayotzinapa Teacher Training College Raul Isidro Burgos in Tixtla, on the outskirts of Chilpancingo, in the Mexican state of Guerrero, October 14, 2014. On September 26, police allegedly linked to a criminal gang shot dead at least three students and abducted dozens of others during clashes in the southwestern city of Iguala. Forty-three of the students are still missing. (Photo by Jorge Dan Lopez/Reuters)

Mechanic and welder Sergei Kulagin, 32, strengthens the bracing of a spider sculpture, made by Kulagin, during a demonstration on the wall of an automobile repair workshop in the town of Divnogorsk outside Krasnoyarsk, Siberia, October 15, 2014. Enthusiast Kulagin, who works as a mechanic of an automobile service station, created about 20 sculptures made of used car parts and components during his non-working hours. (Photo by Ilya Naymushin/Reuters)

Mechanic and welder Sergei Kulagin, 32, tests the “Alien Samurai”, an electro-mechanical mobile robot made by Kulagin using car components, outside an automobile repair workshop in the town of Divnogorsk outside Krasnoyarsk, Siberia, October 15, 2014. (Photo by Ilya Naymushin/Reuters)

A train engineer looks out of a historic steam locomotive as it pulls a Tehran-bound train into Nyugati Terminus in Budapest, October 15, 2014. The train, a set of luxury cars retrofitted from historic models to reflect times gone by, will take two weeks to wind through the 7,000 kilometre journey across the Balkans, the Bosphorus and eastern Turkey to arrive in Iran. (Photo by Laszlo Balogh/Reuters)

A student jumps in front of the building of the office of Mexico's Attorney General during a protest in support of missing Ayotzinapa Teacher Training College Raul Isidro Burgos students in Mexico City October 15, 2014. On September 26, police allegedly linked to a criminal gang shot dead at least three students and abducted dozens of others during clashes in the southwestern city of Iguala. Forty-three of the students are still missing. (Photo by Edgard Garrido/Reuters)

Models wait backstage during Ukrainian Fashion Week in Kiev October 15, 2014. (Photo by Gleb Garanich/Reuters)

A man wearing a bra dances to attract customers at his lamb kebabs stand in Yongkang, Zhejiang province October 15, 2014. Picture taken October 15, 2014. (Photo by Reuters/Stringer)

A women presents body painting art on the opening day of the 18th Venus fair, in Berlin October 16, 2014. The Venus, the worlds largest erotic fair, takes place from October 16–19. (Photo by Hannibal Hanschke/Reuters)

Russian aerobatic team Strizhi (The Swifts) performs on MIG-29s during a military parade to mark 70 years since the city's liberation by the Red Army in Belgrade October 16, 2014. Serbia feted Russia's Vladimir Putin with troops, tanks and fighter-jets on Thursday to mark seven decades since the Red Army liberated Belgrade, balancing its ambitions of European integration with enduring reverence for a big-power ally deeply at odds with the West. (Photo by Marko Djurica/Reuters)

A traditionally dressed representative from a South Pacific nation installs a flag in a canoe on the shores of a beach as they prepare to participate in a protest aimed at ships leaving the Newcastle coal port, located north of Sydney October 17, 2014. Around 100 protesters, which included 30 representatives of 12 South Pacific nations, formed a blockade using traditional canoes and kayaks to the entrance of the world's largest coal port demanding a global change to the use of coal. (Photo by David Gray/Reuters)

A woman bows in respect to a Buddhist monk after offering alms to him on a main road in Colombo October 17, 2014. (Photo by Dinuka Liyanawatte/Reuters)

People watch a mechanical installation named “Long Ma” emit water vapour during the Long Ma performance in front of the National Stadium, also known as the Bird's Nest, in Beijing October 17, 2014. “Long Ma”, a 17-meter (56-ft) long and 15-meter (49-ft) tall mechanized dragon sculpture, and “The Spider”, a 5.7-meter (19-ft) tall and 6-meter (20-ft) wide machine, are operated by French performance art company La Machine. The structures are operated by an automatic control system and electronic equipment. The performance, which combines Chinese culture and French art, was held in Beijing in honour of the 50th anniversary of the establishment of diplomatic relations between the two countries, an organiser of the event said. (Photo by Kim Kyung-Hoon/Reuters)

French production company La Machine's latest creation the Long Ma or Dragon Horse goes through rehearsals before performing in front of the Bird's Nest Stadium in Beijing, China, Thursday, October 16, 2014. The three-day performances mark the climax of celebrations for the 50th anniversary of Sino-French diplomatic relations on Sunday, Oct. 19. (Photo by Ng Han Guan/AP Photo)

A visitor looks at the creation “Where the Slaves Live”, 2014, by Argentine artist Adrian Villar Rojas during a press visit at the Fondation Louis Vuitton designed by architect Frank Gehry in the Bois de Boulogne, western Paris, October 17, 2014. Reflecting sky, clouds and light, the airy and audacious building designed by Los Angeles-based architect Gehry and built on a one-hectare plot in the west of Paris resembles a swaying ship sitting next to a cascading rectangular pool of water. The Louis Vuitton Foundation for Creation, an art museum and cultural center, will open to the public on October 27, 2014 after three special open days for the Inaugural Weekend. (Photo by Benoit Tessier/Reuters)

A protester is carried away by other protesters over a fence as he is charged by riot police during a confrontation at Mongkok shopping district in Hong Kong October 17, 2014. Hong Kong riot police used pepper spray and baton charged crowds of pro-democracy protesters on Friday evening as tension escalated after a pre-dawn clearance of a major protest zone in the Chinese-controlled financial hub. (Photo by Bobby Yip/Reuters)

A view shows a model of the Fondation Louis Vuitton designed by architect Frank Gehry during a press visit at the Fondation in the Bois de Boulogne, western Paris, October 17, 2014. Reflecting sky, clouds and light, the airy and audacious building designed by Los Angeles-based architect Gehry and built on a one-hectare plot in the west of Paris resembles a swaying ship sitting next to a cascading rectangular pool of water. The Louis Vuitton Foundation for Creation, an art museum and cultural center, will open to the public on October 27, 2014 after three special open days for the Inaugural Weekend. (Photo by Benoit Tessier/Reuters)

An exterior view shows the new Investigative Isolator “Kresty-2” (Crosses-2) detention centre, which is under construction, in St. Petersburg, Russia, October 17, 2014. “Kresty-2”, which will be the largest prison complex in Europe when it is finished as planned in 2016, has been designed for the maintenance of 4000 criminal suspects, according to a representative of the Russian Federal Penitentiary Service. (Photo by Alexander Demianchuk/Reuters)

Marijuana-infused sour gummy bear candies (L) are shown next to regular ones at right in a photo illustration in Golden, Colorado October 17, 2014. As children around the country prepare their costumes in anticipation of Halloween goodies on Oct. 31, police in Colorado are warning parents that some treats may not be all they seem. Since Colorado and Washington this year became the first U.S. states to allow recreational sales of pot to adults, much of the public debate has focused on marijuana-infused products such as chocolates, cookies and candies, given their potential to attract children or be eaten accidentally. (Photo by Rick Wilking/Reuters)

Two women talk outside their makeshift homes, part of the Nova Tuffy slum, in an abandoned factory in Rio de Janeiro October 17, 2014. Since seven months ago, 1,800 families have been living inside the factory, which they occupied in March, with poor sanitation services and the fear of eviction. The occupants of the factory say they are not included in the housing program “Minha Casa, Minha Vida” (My House, My Life), and they would like to be included by the Brazilian government. The housing program is one of several government initiatives aimed at reducing poverty and social inequality that President Dilma Rousseff has held up as achievements of her administration as she campaigns for re-election. (Photo by Pilar Olivares/Reuters)

The X-37B Orbital Test Vehicle mission 3 space plane is shown after landing at Vandenberg Air Force Base, California October 17, 2014 in this handout photograph provided by Vandenberg Air Force Base. The United States military landed the robotic space plane in central California on Friday, ending a classified 22-month mission that marked the third in Earth orbit for the experimental program, the Air Force said. (Photo by Reuters/Boeing/Vandenberg Air Force Base)

Yamaha MotoGP riader Valentino Rossi of Italy performs a wheelie during the a practice sesson for the Australian Grand Prix on Phillip Island October 18, 2014. (Photo by Jason Reed/Reuters)

Models present creations by Colombian designer Hernan Zajar during the Cali Exposhow in Cali, Colombia, October 17, 2014. (Photo by Jaime Saldarriaga/Reuters)

A general view of atmosphere during the 2014 New York Comic Con at Jacob Javitz Center on October 12, 2014 in New York City. (Photo by Daniel Zuchnik/Getty Images)

Sri Lankan ethnic Tamil workers react to the camera as they rest on a rail track at the Jaffna railway station Sri Lanka, Sunday, October 12, 2014. The “Queen of Jaffna”, a once-popular train linking the ethnic Tamil's northern heartland to the rest of Sri Lanka before a bloody civil war cut the link 24 years ago, chugs back into service this coming week, reinforcing the government's authority in a region once controlled by Tamil rebels. (Photo by Eranga Jayawardena/AP Photo)

An Ebola burial team, dressed in protective clothing, carries the body of a woman, 54, from the bedroom where she died in the New Kru Town suburb on October 10, 2014 of Monrovia, Liberia. The World Health Organization says the Ebola epidemic has now killed more than 4,000 people in West Africa. (Photo by John Moore/Getty Images)

Two boys lay on a 3-D floor painting pretending to try to reach eath other across a gutter caused by an earthquake at the Taipei Astronomical Museum, in Taipei, Taiwan, October 16, 2014. 3-D floor paintings or pavement paintings create illusions of three-dimensional impressions. (Photo by David Chang/EPA)

Two cosplayer pose at the “Frankfurter Buchmesse” on October 12, 2014 in Frankfurt am Main, Germany. Cosplay is a contraction of the words “costume” and “play” together. Cosplayer live their hobby with animated films, comics and mangas and role playing. (Photo by Thomas Lohnes/Getty Images)

Revelers celebrate during an LGBT pride march on Copacabana Beach on October 12, 2014 in Rio de Janeiro, Brazil. The city will host the Rio 2016 Olympic Games in less than two years. (Photo by Mario Tama/Getty Images)

A woman walks past the installation “Waechter der Zeit” (lit. guardians of time) at Potsdamer Platz in Berlin, Germany, October 16, 2014. The three sculptures are on display as part of the “Festival of Lights” until Ocotober 19. (Photo by Stephanie Pilick/EPA)

Volunteers participate in an earthquake drill during an event on earthquake preparedness October 14, 2014 at the National Building Museum in Washington, DC. Federal and local officials joined national experts to discuss earthquake preparedness and to provide details regarding the upcoming international Great ShakeOut day of action, an earthquake drill taking place on Thursday, October 16. (Photo by Alex Wong/Getty Images)

Aid workers from the Liberian Medical Renaissance League stage an Ebola awareness event on October 15, 2014 in Monrovia, Liberia. The group performs street dramas throughout Monrovia to educate the public on Ebola symptoms and the handling of people who are infected with the virus, which has killed more than 4,400 people in Western Africa. (Photo by John Moore/Getty Images)