High school teachers in Durham are trading books for picket signs today.  Members of the Ontario Secondary School Teachers Federation went on strike Monday morning after talks broke down last week.  Some 24 thousand students are impacted  Both sides blame each other.  The chair of the Durham School Board says his side is ready to resume talks.  Teacher’s spokesman Dave Barrowclough says they’ll go back when the board is ready to engage in “meaningful” discussions.   Education Minister Liz Sandals says the government is committed to a bargaining process that is in line with its fiscal plan.  No new talks are planned.