Southern Illinois University appears ready to name a new interim chancellor for its Carbondale campus.  The SIU Board of Trustees’ executive committee is expected to meet today in Carbondale, and the only agenda item is to appoint a temporary replacement for Rita Cheng.  Cheng has been named president of Northern Arizona University in Flagstaff.  SIU President Randy Dunn says Cheng completed her work on the Carbondale campus Monday and is taking vacation leave pending the start of her new job in two weeks.  Cheng has been the Carbondale school’s chancellor since 2010.