1. Department of Human Development & Family Studies, Iowa State University, Ames, IA 50011-1120, USA
2. Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
3. Clinical Thanatology and Geriatric Behavioral Science, Osaka University, Osaka 565-0871, Japan
4. Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE 68503, USA
5. Institute of Gerontology, University of Georgia, Athens, GA 30602, USA