1. Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Institutes of Health/Department of Health and Human Services, Bethesda, MD and Detroit, MI, and Department of Obstetrics and Gynecology, Wayne State University; Perinatology Research Branch; Detroit Michigan USA
2. Departamento de Neonatologia del Hospital de Clínicas; Universidad de la Republica Montevideo Uruguay