A small wad of cash sits in a glass beaker labelled ‘motivation’, in a safe inside John Tregoning’s office. A vaccine immunologist at Imperial College London, Tregoning sticks some money in the beaker every time someone in his laboratory has a paper published. If the group publishes ten papers in one year, he doubles the cash. The proceeds fund a team dinner at the end of the year. “I quite like the cash as a physical reminder of the motivation,” he says.