1. Children's Hospital of Philadelphia; Department of Pediatrics; 34th Street and Civic Center Boulevard Philadelphia Pennsylvania USA 19104
2. Larner College of Medicine at the University of Vermont; Division of Neonatal-Perinatal Medicine, Department of Pediatrics; Burlington Vermont USA 05401
3. Larner College of Medicine at the University of Vermont; Division of Pediatric Cardiology, Department of Pediatrics; 111 Colchester Avenue Burlington Vermont USA
4. Dalhousie University & IWK Health Care; Division of Neonatal Perinatal Medicine, Department of Pediatrics; G-2214, 5850/5980 University Avenue Halifax Nova Scotia Canada B3K 6R8