Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

Model presents a creation from the Amir Slama collection during Sao Paulo Fashion Week in Sao Paulo, Brazil August 30, 2017. (Photo by Paulo Whitaker/Reuters)

Models present creations from Vislumbre during Fashion Weekend Plus Size in Sao Paulo, Brazil, March 19, 2017. (Photo by Paulo Whitaker/Reuters)

Girls dressed in Soviet WWII uniforms of traffic control officers as Russian President Vladiimir Putin lays a wreath in the Hall of Military Glory of the Mamayev Kurgan memorial complex commemorating the Battle of Stalingrad to mark the 75th anniversary of the victory in the battle in Volgograd, Russia on February 2, 2018. The battle between Nazi troops and the Soviet Army was a major pivotal moment in the Great Patriotic War and World War II. (Photo by Mikhail Metzel/TASS via Getty Images)

Florin Bors, aged 8 from Bacau, northern Romania, wearing a bear fur takes a break from performing a holiday season ritual in Bucharest, Romania, Tuesday, December 16, 2014. In pre-Christian rural traditions, dancers wearing colored costumes or animal furs, touring house to house in villages singing and dancing to ward off evil. In recent years following the economic downturn in Romania, a European Union member since 2007, the tradition has moved to Romania's cities where dancers travel to perform the ritual for money. (Photo by Octav Ganea/AP Photo/Mediafax)

A country music fan cools off in the wind on the second day of the Stagecoach country music festival in Indio, California April 26, 2014. (Photo by Mike Blake/Reuters)

American fashion model Simone Thompson, better known as Slick Woods walks at the Savage x Fenty – September 2018 – New York Fashion Week at Brooklyn Navy Yard on September 12, 2018 in Brooklyn, New York. (Photo by Presley Ann/Patrick McMullan via Getty Images)

In the mountains of central Vietnam, a colossal pair of hands lifts a golden thread of walkway high above the clifftops, as if the mountain itself has sprouted limbs. Here: A giant hand structure at the Gold Bridge is seen on Ba Na hill near Danang city, Vietnam on August 1, 2018. (Photo by Reuters/Kham)