Ramatu Usman, shown here with one of her sons, is a 37-year-old mother of eight. She says she was separated from one of her sons, 6-year-old Yahaya Buba, following an attack. He is still missing. Ofeibea Quist-Arcton/NPR hide caption

itoggle caption Ofeibea Quist-Arcton/NPR

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