Jo - Ann Hamilton - Smith wins women 's 100 m at world championships . Diminutive Jamaican runs fastest time of the season . Build up to event marred by positive doping results . Christine Ohuruogu dips for 100 m gold .
Shelly-Ann Fraser-Pryce wins women 's 100m at world championships . Diminutive Jamaican runs fastest time of the season . Build up to event dominated by positive doping tests . Christine Ohuruogu dips for 400m gold .