Three women’s rights activists accepted the vaunted 2011 Nobel Peace Prize, while urging women to fight against male oppression. "My sisters, my daughters, my friends - find your voice," Liberian President Ellen Johnson Sirleaf said after collecting her Nobel diploma and medal at a ceremony in Oslo. Sirleaf, Africa's first democratically elected female president, shared the award with women's rights campaigner Leymah Gbowee, also from Liberia, and Tawakkul Karman, a female icon of the protest movement in Yemen. Early Life Ellen Johnson was born on October 29th, 1938, in Monrovia, Liberia. Her parents were of “Americo-Liberian” descent – meaning that…