All about circadian rhythm physiology, the effect of light on sleep and much more! The annoying and dangerous practice of prior authorization by insurance companies for important prescriptions and medical procedures; Does blocking estrogen to prevent bone lose make sense? Probenecid is an older drug that is good for gout; Eliminating HIV from cells is difficult, but promising, using CRISPR gene editing; The tricky balance of hormones for satiation and the brain; Exercise enhances memorization tasks; Intestinal cells are replaced ten times faster than skin cells; Preeclampsia risk is reduced by a high fiber diet