A controversial theory of smell involving quantum physics receives a boost as scientists test the idea using human subjects.

US President Barack Obama pays tribute to Hillary Clinton in a joint interview, as both dodge speculation about a presidential bid by Mrs Clinton.

The government launches its Green Deal, with householders offered long-term loans to make their homes more energy efficient and cut bills.

Brazil declares three days of national mourning for 231 people killed in a nightclub fire, reportedly started after a musician lit a flare on stage.

Japanese carmaker Toyota regains its slot as the world's biggest vehicle maker, capping a year of a dramatic turnaround in its fortunes.

French-led troops fighting Islamist rebels in Mali have taken control of the airport in the key northern city of Timbuktu, military officials say.

Ryanair lifts its full-year profit forecast to 540m euros ($725m; £460m) after a better-than-expected performance in the last three months of 2012.

Three councils in Cumbria are due to vote on whether to continue considering a huge underground radioactive waste facility in the county.