Hong Kong Swears in New Chief Executive, Carrie Lam

President Xi Jinping of China swears in the new Chief Executive of Hong Kong, Carrie Lam, at a ceremony in the city; the race for the cure against the onset of Alzheimer's Disease; what the sound of the chatter of bats in a London park can tell us about our health.

(Picture: Carrie Lam gives a speech after being sworn in as Hong Kong's new leader. Credit: Getty Images)