1. Department of Medicine, Washington University, St. Louis, MO, USA
2. Department of Pediatrics, Washington University, St. Louis, MO, USA
3. Department of Public Health, School of Public Health & Family Medicine, Kamuzu University of Health Sciences, Blantyre, Malawi
4. Department of Pediatrics, University of Texas at Austin, Austin, TX, USA
5. Project Peanut Butter, Lunzu, Malawi
6. Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
7. USDA/Agricultural Research Service Children's Nutrition Research Center, Houston, TX, USA