By numbers

The pick of the science news

10

The percentage of premature births among the around 130 million babies born each year, according to the UN. Most are in Asia and Africa, but North America has seen figures rise.

50 million

The number of pandemic H1N1 vaccine orders cancelled by the French government now that one shot, rather than two, is considered sufficient.

On the pulse

An artificial artery which mimics the pulsing of a human blood vessel will go into patient trials this year. A team from London’s Royal Free Hospital has developed the graft material by treating a plastic polymer, using nanotechnology, to mimic the actions of real arteries and address problems associated with more traditional artificial grafts.

“The new micro-graft pulses rhythmically to match the beat of the heart,” says researcher Prof George Hamilton. “As well as this, the new graft material is strong, flexible, resistant to blood-clotting and doesn’t break down – a major breakthrough.”

Stuck on Mars

If your car’s wheels have been spinning on ice of late, spare a thought for Nasa’s Mars rover, Spirit, which is stuck in a sand trap on the red planet. The robotic vehicle went through a crusty surface layer nine months ago and has barely budged since. As the Martian winter approaches, being stranded could leave the solar-powered explorer running low on juice.

More encouraging news comes from the Mars Reconnaissance Orbiter, which has detected channels on the planet’s surface indicating that liquid water (and thus microbial life) was perhaps once present.

Claire O’Connell

e-mail: 1000.claire@gmail.com