Patrick Frater Asia Bureau ChiefDean Stockwell, an American actor with a career that spanned more than 70 years, died on Sunday. He was 85.Sources representing the actor say that he died peacefully, in his sleep at home.Among his best credits were a leading role in the sci-fi series “Quantum Leap,” “Air Force One” and David Lynch films “Dune” and “Blue Velvet.”Born as Robert Dean Stockwell in March 1936, Stockwell began his career as a child actor under contract to Metro-Goldwyn-Mayer.