Class of 2015 graduating students of the American University of Nigeria in Yola, Adamawa state, celebrate after their commencement ceremony at the school on May 9, 2015. Amongst them is Abubakar Umar, a 26-year-old petroleum chemistry student who survived a Boko Haram attack last November as he travelled home to the city of Kano, surviving with the help of villagers and without medication for two broken arms. He returned to finish his education with his arms in casts in January, winning an award for his courage as well as his degree. AFP PHOTO / EMMANUEL AREWA        (Photo credit should read EMMANUEL AREWA/AFP/Getty Images)