Supporters of Ugandan President Yoweri Museveni celebrate his election victory in Kampala, Uganda February 20, 2016. Ugandan President Yoweri Museveni extended his 30-year rule on Saturday, winning an election that international observers said lacked transparency and his main opponent, who was placed under house arrest, denounced as a sham. (Photo by Goran Tomasevic/Reuters)

Manuela (L) and Marta, members of the Revolutionary Armed Forces of Colombia (FARC), pose for a picture at a camp in the Colombian mountains on February 18, 2016. Many of these women are willing to be reunited with the children they gave birth and then left under protection of relatives or farmers, whenever the peace agreement will put an end to the country's internal conflict. (Photo by Luis Acosta/AFP Photo)

Afghan dogs fight during the weekly dog fight in Kabul, Afghanistan, 17 February 2017. Under the Taliban dog fighting was forbidden, but since their fall it has become a major source of entertainment for hundreds of Afghans, where bets can amount to thousands of dollars and the dogs, which must be over one year old, are well-cared for by their owners and fed milk, butter and meat. (Photo by Hedayatullah Amid/EPA)

Soap Bubble Structures by Kym Cox. Bubbles optimise space and minimise their surface area for a given volume of air. This phenomenon makes them a useful tool in many areas of research, in particular, materials science and “packing” – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom, which interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst. (Photo by Kym Cox/2019 Science Photographer of the Year/RPS)

Children watch their classmate pour cold water on herself under the watch of a fitness coach at a local kindergarten in Russia's Siberian city of Krasnoyarsk, March 11, 2015. The program, which also involves sports training and sauna usage, has been practiced by the kindergarten for more than 15 years as they believe it has health benefits and keeps the children fit. Children start pouring cold water on themselves outdoors after about three years of training and undergoing medical tests, and the kindergarten is the only one in the region that practices these exercises, according to employees. (Photo by Ilya Naymushin/Reuters)

An Airbus A380 aircraft prepares to land at Mumbai airport in this May 8, 2007 file photo. Sentiment at some of Asia's biggest firms deteriorated again in the fourth quarter, falling to a four-year low under the weight of concerns about slowing growth in China, the region's biggest economy, a Thomson Reuters/INSEAD survey showed. (Photo by Arko Datta/Reuters)

In this photo taken on Saturday, January 26, 2019 photo, rescued flamingo chicks have access to water at a centre after being rescued from a dried out dam in Kimberley, South Africa. A special airlift for thousands of baby flamingos is under way in South Africa as drought has put their breeding ground in peril. A reservoir that hosts one of southern Africa's largest flamingo populations is drying up. (Photo by AP Photo/Stringer)

An orphaned giraffe nuzzling a wildlife keeper at Sarara camp in Kenya, one of 70 pictures being sold by Prints for Nature (printsfornature.com) to raise money for work by the Conservation International charity. This giraffe was rehabilitated and returned to the wild, as a number of others have done before him. Right now, giraffe are undergoing what has been referred to as a silent extinction. Current estimates are that giraffe populations across Africa have dropped 40 percent in three decades, plummeting from approximately 155,000 in the late 1980s to under 100,000 today. (Photo by Ami Vitale/National Geographic)