Alzheimer's fingerprick test, and space debris sonic booms

This week, a blood finger-prick test has been developed to detect Alzheimer's disease before symptoms arise. But how accurate is it? Plus, tracking space debris reentry from their sonic booms with earthquake-detecting seismometers, what happens in our noses when we are infected by the common cold, and the plants that use heat to get pollinated by beetles... Like this podcast? Please help us by supporting the Naked Scientists (thenakedscientists.com/donate)