People call for the Nigerian government to rescue girls taken from a secondary school in Chibok region, during a protest earlier this month. Boko Haram, the group that took the girls, says they have been "married off." Olamikan Gbemiga/AP hide caption

itoggle caption Olamikan Gbemiga/AP

Zambia's then-opposition leader Michael Sata speaks to journalists during a news conference in Lusaka in 2006. Sata, who became president in 2011, died while being treated for an undisclosed illness in London. Siphiwe Sibeko/Reuters/Landov hide caption

itoggle caption Siphiwe Sibeko/Reuters/Landov

Congolese editor Solange Lusiku Nsimire says journalism is a powerful way of building and preserving her troubled country's "collective memory." Sylvain Muyali/Courtesy of IWMF hide caption

itoggle caption Sylvain Muyali/Courtesy of IWMF

US soldiers have intervened in during natural disasters such as the 2010 earthquake in Haiti. But a disease outbreak is more complicated. SSgt. Chad Chisholm/U.S. Dept. of Defense hide caption

itoggle caption SSgt. Chad Chisholm/U.S. Dept. of Defense

Alieu P. Manor, 18, survived Ebola. He gazes into the room of his cousin, Varlee Kanneh, who was not so lucky. Tommy Trenchard for NPR hide caption

itoggle caption Tommy Trenchard for NPR

Seun Dupe sits with her newborn twins in a maternity hospital in Lagos, Nigeria. Nigeria is Africa's most populous country with more than 160 million people. UNICEF estimates that number will swell to nearly 1 billion by 2100. Sunday Alamba/AP hide caption

itoggle caption Sunday Alamba/AP

Vital Sounouvou is an African entrepreneur who founded Exportunity.com, a company to help promote trade in Africa. Courtesy of Vital Sounouvou hide caption

itoggle caption Courtesy of Vital Sounouvou

Satao was a 45-year-old Kenyan elephant with tusks so long they brushed the ground. Poachers killed him in June with a poisoned arrow. African leaders gathered in Washington said there needs to be better cooperation on the continent to prevent poaching. Tsavo Trust hide caption

itoggle caption Tsavo Trust

Scores of African leaders gather in Washington this week at an unprecedented summit organized by President Obama. Paul J. Richards /AFP/Getty Images hide caption

itoggle caption Paul J. Richards /AFP/Getty Images