Bogus 'Obama injured' tweet upsets US markets

Hackers took over news agency Associated Press's Twitter account and sent a false tweet about the US president that briefly sent US markets reeling.

Deep Read: In election ads, political science meets excess

Amid the chaos of the US election campaign's closing days, Ohio has become a test centre for the growing science of political advertising.

US researchers broke rules in Guatemala syphilis study

US researchers must have known they were violating ethical standards by infecting Guatemalan prison inmates and mental patients with syphilis.