BERLIN (AP).- A German university says recently released Chinese artist Ai Weiwei has accepted an offer to join the Berlin institution as a visiting lecturer. Berlin’s University of Arts said Wednesday it was unclear when Ai will be able to start in his new position due to his legal troubles in China. University president Martin Rennert says he hopes Ai will be able to join “in the near future.” The university first published the offer — in the works since December — following Ai’s arrest on tax fraud charges in April. He was released June 22, but Chinese authorities say he is still under investigation for at least a year. The prominent government critic was the highest-profile target of a crackdown on activists in China this year. His