TechnologyWearable sweat sensor shows how hydrated you are during workouts Fitness fans will soon have a gadget that tells them when to take a drink and when their muscles have had enough – but it could also have medical uses News
LifeHow giant viruses could rewrite the story of life on Earth They're huge and they lurk everywhere. But don't fear, these giants seem to be gentle – and might even have taught our own cells a few neat tricks Features