Rick Santorum and Mitt Romney finish the Iowa caucuses in a virtual tie, with Mr Santorum leading by 34 votes with 99% of the vote counted.
Bethany Bell visited the Zwentendorf atomic power plant near Vienna which never went online.
US Republicans bidding to challenge Barack Obama for the White House prepare for the Iowa caucuses, the first official test of the 2012 campaign.
A Twitter account written under the name of Rupert Murdoch’s wife Wendi Deng is revealed to be a fake.
The BBC’s Matt Danzico investigates how augmented reality mobile apps may help to change people’s perceptions of the world around them.
Exxon wins $908m from an arbitration panel after the nationalisation of its Venezuelan assets, a great deal less than it sought.