TOPSHOTS Teachers block access to Mexico's chamber of senators to protest education reform legislation, in Mexico City on August 22, 2013. President Enrique Pena Nieto pushed through Congress changes to the constitution in December in order to put education, which was in the hands of powerful unions, back under government control and require teachers to undergo mandatory performance appraisals. Lawmakers are now debating legislation that would implement the new laws, which have prompted protests and strikes in some states. The teachers say the mandatory testing should only be used to help them improve, not to fire them or decide promotions. TOPSHOTS/AFP PHOTO/OMAR TORRES