There's nothing quite like having your own living visual aid on stage with you during a high-powered seminar. Lucky in this respect at a recent Keele University seminar were Peter Jones, professor of medical statistics, and Klim MacPherson, professor of public health epidemiology at the London School of Hygiene and Tropical Medicine. Chair of the event was Keele's chancellor Sir Claus Moser, evidently at present both medical statistic and beneficiary of public health treatment as he turned up with his left arm in sling and plaster.