Images of children â€" splashing in brown lake water, basking in the sun on the hull of a sailboat, holding hands and making funny faces â€" adorn the bookshelves in Bill Schultz’s office.Schultz, a physician assistant, is a clinical associate in Duke’s Department of Pediatrics, Division of Hematology-Oncology. For more than 20 years, he has cared for children who are battling cancer or sickle cell disease. The photos on his...