U.S. President Barack Obama speaks at the Righteous Among the Nations Award Ceremony, organised for the first time in the U.S. by Yad Vashem, at the Embassy of Israel in Washington January 27, 2016. Photo: ReutersA technician of Oswaldo Cruz Foundation (Fiocruz) inspects an Aedes aegyti mosquito through a microscope inside of a laboratory in Recife, Brazil, January 27, 2016. Photo: ReutersChildren attend prayers to pay respects to the Kenyan soldiers serving in the African Union Mission in Somalia (AMISOM), who were killed in El Adde during an attack, at a memorial mass at the Moi Barracks in Eldoret, January 27, 2016. Photo: ReutersSoldiers of the People`s Liberation Army (PLA) Marine Corps are seen in training at a military training base in Bayingol, Xinjiang Uighur Autonomous Region, January 20, 2016. Photo: ReutersSerena Williams of the U.S. (L) and Poland`s Agnieszka Radwanska shake hands after Williams won their semi-final match at the Australian Open tennis tournament at Melbourne Park, Australia, January 28, 2016. Photo: ReutersGeovane Silva holds his son Gustavo Henrique, who has microcephaly, at the Oswaldo Cruz Hospital in Recife, Brazil, January 26, 2016. Photo: ReutersMechanic and welder Sergei Kulagin (R), 33, and his collegues work on the `Alien Aggressor`, an electro-mechanical robot inside an automobile repair workshop in the Siberian town of Divnogorsk outside Krasnoyarsk, Russia, January 27, 2016. Photo: ReutersA Muslim bride waits for the start of a mass marriage ceremony in Mumbai, India, January 27, 2016. Photo: ReutersA yellow Gerbera is seen at Ramna Park in the capital. Photo: Makdusuzzaman RobinMarigolds are seen at Ramna Park in the capital. Photo: Makdusuzzaman Robin