Nicholas J Talley MD, PhD, FRACP, FRCP (London), FRCP (Edin), FAFPHM, FACP, FACG Professor of Medicine, Mayo Clinic Rochester, Minnesota ; Consultant Physician. Simon O'Connor FRACP, DDU, FCSANZ ; Cardiologist, The Canberra Hospital ; Clinical Senior Lecturer, Australian National University Medical School, Canberra, ACT.