JOHANNESBURG (AP) — In a speech marking the 100th birthday of anti-apartheid leader Nelson Mandela, former U.S. President Barack Obama will urge youth around the world to work for human rights and fair societies, highlighting the late South African leader's example of persevering in the struggle for democracy and equal rights for all. The speech on Tuesday, one of Obama's most high-profile since leaving office, is meant to draw attention to values that today are under threat and to rally people in Africa and elsewhere to push for tolerance and justice.Read more on NewsOK.com