Former teacher of the Department of History and Culture of Islam at Rajshahi University, Professor Emeritus  A. B. M. Hossain passed away on Saturday. He was 90.   “Prof Hossain passed away at 2:30 pm at Bangladesh Specialized Hospital in the capital,” said family sources.   He has left many admirers, including children, grandchildren to mourn his death.   Professor Hossain will be buried at Mirpur Cemetery after Janazah prayers at Kalabagan Dolphin Lane Jame Mosque in the capital after Asr.