One of Louisiana's best-known "watch-dogs" has passed away.  Art Thiel first joined the public affairs research council in 1959 as its Research Director. In 1975, he became its president and served in that capacity until his retirement in November of 1984. Now, PAR has confirmed that Thiel passed away Saturday at his home in Wilkesboro, North Carolina. He was 91 years old. His family plans to hold a celebration of his life at the Holiday Inn Express on Siegen Lane Circle in Baton Rouge next Thursday evening and a graveside memorial service the next morning at the Port Hudson National Cemetery in Zachary.