1. From the Neonatology services at Thomas Jefferson University, Philadelphia, Pennsylvania;
2. Providence Alaska Medical Center, Anchorage, Alaska;
3. West Jersey Hospital, Voorhees, New Jersey;
4. Diego Paroissien Hospital, Buenos Aires, Argentina;
5. Mercer Medical Center, Trenton, New Jersey;
6. Fitzgerald Mercy Hospital, Darby, Pennsylvania;
7. Flushing Hospital, Flushing, New York;
8. University Hospital, Buenos Aires, Argentina;
9. Clinicas Hospital, Asúncion, Paraguay;
10. Pennsylvania Hospital, Philadelphia, Pennsylvania;
11. Desert Samaritan Medical Center, Phoenix, Arizona; and
12. Scott and White Memorial Hospital, Temple, Texas.