First up this week, Staff Writer Meredith Wadman talks with host Sarah Crespi about how male sex hormones may play a role in higher levels of severe coronavirus infections in men. New support for this idea comes from a study showing high levels of male pattern baldness in hospitalized COVID-19 patients. Read all our coronavirus coverage. Next, Jason Qian, a Ph.D. student in the systems biology department at Harvard Medical School, joins Sarah to talk about an object-tracking system that uses bacterial spores engineered with unique DNA barcodes. The inactivated spores can be sprayed on anything from lettuce, to wood, to sand and later be scraped off and read out using a CRISPR-based detection system. Spraying these DNA-based identifiers on such things as vegetables could help trace foodborne illnesses back to their source. Read a related commentary piece. This week’s episode was produced with help from Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).