Seven Days

A glance at the week that was

900The estimated decrease in the Irish male population in the year to April 2012, the first such decrease since 1990, according to the CSO.

700,000Number of refugees the UN predicts will flee Syria by the end of the year.

€19 millionGuide price for one of Francis Bacon's "Screaming Pope" paintings, which is to be auctioned in New York in November

58,500Size in tonnes of the Liaoning, China's first aircraft carrier, which entered service this week.

64Number of people injured in violent anti-austerity protests in Madrid on Wednesday.

1 million

Litres of beer drunk in the first two days of Oktoberfest, which opened this week in Munich.

We now know

Bill Clinton believes he could run for the presidency of Ireland and, possibly, of France, the former US president told CNN.

Scientists have identified the stem cells responsible for declining muscle repair in ageing, and have halted the process in mice.

A series of huge earthquakes off the coast of Sumatra in April may be the first signs of a new tectonic plate boundary emerging under the Indian Ocean, according to Nature.

Mona Lisa's secret

It is the most famous painting in the world, and it features the most famous smile, but the Mona Lisa is not alone: Leonardo da Vinci painted another version of the portrait a decade before he created the one that hangs in the Louvre, according to the Mona Lisa Foundation. At a press conference in Switzerland on Thursday, the foundation claimed it has established that the so-called Isleworth Mona Lisa is an original work by da Vinci. An Irish-born art historian, Stanley Feldman, who is a member of the foundation, claims it has taken 35 years to determine the authenticity of the other La Giaconda. Other art historians, inevitably, dispute the claims.