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)

This photo released Saturday March 22, 2014 by Stichting Ambulance Wens or Ambulance Wish Foundation shows a giraffe at Blijdorp Zoo in Rotterdam giving a lick to terminally ill Mario Eijs on Wednesday March 19, 2014. The Stichting Ambulancewens “Ambulance Wish Foundation” offers transport for terminally ill patients who cannot walk to help fulfill a last wish, in Eijs' case to be taken to the Blijdorp Zoo in Rotterdam where he worked doing odd jobs for 25 years. Eijs, who has a mental handicap, is dying of a brain tumor and has difficulty walking or speaking. (Photo by AP Photo/Stichting Ambulance Wens)

A demonstrator is detained by police officers during clashes in downtown Barcelona, Spain, Friday, October 30, 2020. Clashes have erupted in a central Barcelona square between anti-riot police and hundreds who had gathered to protest the mandatory closure of bars, restaurants and other businesses in the latest effort to rein in on coronavirus outbreaks. (Photo by Joan Mateu/AP Photo)

People take part in fake festival called “La Boum” organized by an anonymous group of people on Facebook for an April 1 joke at the Bois de la Cambre, in Brussels, Belgium, 01 April 2021. An anonymous group created a Facebook event called “La Boum”, touting an alleged festival to take place with famous DJs as headliners. Thousands of people on social media had shown interest to take part in the gathering, while police have advised that no authorization has been given for a music event. (Photo by Stephanie Lecocq/EPA/EFE)

A priest sprinkles holy water on a believer during the Orthodox Easter service in the Holy Transfiguration Cathedral in the rebel-controlled city of Donetsk, Ukraine on May 2, 2021. (Photo by Alexander Ermochenko/Reuters)

Photographers take photographs of the Large Air Tanker (LAT) C-130 Hercules, also known as “Thor”, as it drops a load of around 15,000 litres during a display by the Rural Fire Service ahead of the bushfire season at RAAF Base Richmond Sydney, Australia, September 1, 2017. (Photo by David Gray/Reuters)

In advance of Fleet Week performances, the U.S. Navy Blue Angels and Team Oracle aerobatics pilot Sean D. Tucker fly over the San Francisco Bay during a photo flight on Thursday, October 5, 2017. (Photo by Noah Berger/AP Photo)

Thai Princess Bajrakitiyabha (R) and Princess Sirivannavari Nariratana take part in the funeral procession for the late Thai king Bhumibol Adulyadej in Bangkok on October 26, 2017 A sea of black- clad mourners massed across Bangkok' s historic heart early on October 26 as funeral rituals began for King Bhumibol Adulyadej, a revered monarch whose passing after a seven- decade reign has left Thailand bereft of its only unifying figure. (Photo by Damir Sagolj/Reuters)