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)

A woman is assisted while crossing a flooded street after the Huayco river overflooded its banks sending torrents of mud and water rushing through the streets, in Huachipa, Peru on March 17, 2017. Muddy water spilled onto streets and into homes on Thursday in a new round of unusually heavy rains that has killed at least a dozen people in Peru and now threatens flooding in the capital. (Photo by Guadalupe Pardo/Reuters)

A truck is seen in a hole after part of the structure of a bridge collapsed into a river in Changchun, Jilin province May 29, 2011. Two truck passengers were injured, while the cause of the accident is still under investigation, local media reported. (Photo by Reuters/China Daily)

An employe of Russian Space Training Center hangs out to dry space suits of Russian cosmonaut Anatoly Ivanishin, NASA's U.S. flight engineer Kathleen Rubins, and Japanese space agency's flight engineer Takuya Onishi, right, after their undergoing training near in Noginsk, 60 km (38 miles) east of Moscow, Russia, Wednesday, July 2, 2014. The training was intended to simulate the capsule landing on water. Russian cosmonaut Anatoly Ivanishin, Japanese space agency's flight engineer Takuya Onishi, and NASA's U.S. flight engineer Kathleen Rubins are being trained for a future mission to the International Space Station. (Photo by Alexander Zemlianichenko/AP Photo)

Women breastfeed their babies at an event promoting the freedom of mothers to breastfeed in public, during World Breastfeeding Week, at the Village Museum in Bucharest Romania, Saturday, August 6, 2016. (Photo by Andreea Alexandru/AP Photo)

A human rainbow is created at a BASEOrlando coordinated event, “Orlando Strong Body Paint”, on Friday, June 17, 2016 in Orlando, Fl. The group created the rainbow, composed of volunteers numbering the same as that of the victims of the Pulse shooting, as a visual reminder of the amount of lives lost. (Photos by Amanda Voisard/The Washington Post)

A performer poses during celebrations after Rahul Gandhi, newly elected president of India's main opposition Congress party, took charge as the president during a ceremony outside the party's headquarters in New Delhi, India, December 16, 2017. (Photo by Altaf Hussain/Reuters)

Poland's Piotr Lisek celebrates after winning in the Men's pole vault during the IAAF Diamond League competition on July 12, 2019 in Monaco. (Photo by Eric Gaillard/Reuters)