1. a School of Nursing, University of California at Los Angeles , Factor Building, Room 5-238, Box 956918, Los Angeles, CA, 90095-6918 E-mail:
2. b School of Nursing, University of California at Los Angeles , Factor Building, Room 2-248, Box 951702, Los Angeles, CA, 90095-1702
3. c School of Nursing, University of Texas at Austin , Austin, TX, 78701-1499