Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

Protesters wearing masks perform during anti-austerity and anti-graft protests in Ljubljana, Slovenia, on January 11, 2013. More than 5,000 Slovenians gathered in the center of Ljubljana on Friday to protest against a corruption scandal that threatens to bring down the government. Slovenia's anti-corruption commission said earlier this week that Prime Minister Janez Jansa had been unable to explain the source of some of his income in recent years. (Photo by Srdjan Zivulovic/Reuters via The Atlantic)

A penitent called “Morion” checks his mobile phone in Mogpog town on Marinduque island in central Philippines April 14, 2014. During the annual festival, masked and costumed penitents called “Moriones” dress in attire that is the local interpretation of what Roman soldiers wore during biblical times. Holy Week is celebrated in many Christian traditions during the week before Easter. (Photo by Erik De Castro/Reuters)

Tourists gather to watch Mount Agung at Amed beach in Karangasem on Indonesia' s resort island of Bali on November 30, 2017. Thousands of foreign tourists were expected to leave Bali by plane on November 30 following a nearly three- day airport shutdown sparked by a rumbling volcano on the Indonesian holiday island. (Photo by Juni Kriswanto/AFP Photo)

Kenyan security forces aim their weapons up at buildings as they run through a hotel complex in Nairobi, Kenya Tuesday, January 15, 2019. Terrorists attacked an upscale hotel complex in Kenya's capital Tuesday, sending people fleeing in panic as explosions and heavy gunfire reverberated through the neighborhood. (Photo by Ben Curtis/AP Photo)

A group of costumed fans attend Comic-Con International at San Diego Convention Center on July 12, 2015 in San Diego, California. (Photo by Daniel Knighton/Getty Images)

A ten days old South American sea lion pup sits next to its mother Lunita at the “Tiergarten Schoenbrunn” Zoo in Vienna, Austria, July 28, 2015. The pup was born in the zoo and weighs about 14 kilograms (30 pounds). (Photo by Leonhard Foeger/Reuters)

A general view of atmosphere at the annual VOLT Festival in Sopron, 208 kms west of Budapest, Hungary on August 16, 2016. (Photo by Mudra László/Rockstar Photographers)