Mexico's powerful dissident teachers movement is again in the streets protesting the government's educational reform and standardized nationwide teacher evaluation exams. And, as before, it has been met with heavy repression and arrests. Teachers and academic specialists charge the reform was drafted without prior consultation with educators. Given the refusal of Public Education Minister Aurelio Nuño to engage in an open and transparent dialogue, the teachers are calling for his resignation. Clayton Conn reports from Mexico City. teleSUR