Ö÷²¥´óÐã

GENE THERAPY TREATS BLINDNESS
A dramatic breakthrough using gene therapy to restore sight. We hear from nine your old Corey Haas who was born with a condition that means he was slowly losing his vision. He wasn't able to play with his friends, ride a bike or even take part in normal classroom activities, but now he can. Corey took part in a trial – he was one of twelve people who were treated with a single injection into the eye. Science in Action speaks to Professor Jean Bennett from the University of Pennsylvania who treated Corey.

FLU EVOLUTION
New research, published in the journal Science shows that the flu virus evolves in stages. It appears that the virus can change in tiny ways each time it copies itself, but major changes tend to occur every two to five years. This means that flu vaccines could offer at least some protection over a number of years. Dr. Andrew Park from the University of Georgia in Athens joins Jon Stewart on the programme and tells him what they found.

HOW TO FIND A NUCLEAR EXPLOSION
Iranian officials were in Vienna recently discussing the country's access to enriched uranium, at the same time an international team of scientists and diplomatic observers headed out of the city and into Slovakia. They were there to test how forensic science may allow them to detect nuclear explosions once the Comprehensive Nuclear-Test-Ban Treaty comes into force. Our reporter Tracey Logan joined them. We also speak to George Tuckwell, the vice-president of the Geological Society of London who took part in a similar exercise in Kazakhstan.

THE OLDEST STAR
It's taken 13 billion years to get here, but astronomers have seen the light of an exploding star – which makes it the most distant object ever observed, and the oldest. The gamma-ray burst was spotted in April and reported this week in the journal Nature. The discovery could help us learn more about the infancy of our universe. Gamma-ray bursts are the most violent explosions known, and they occur when a star dies, probably as it collapses into a black hole. Science in Action invited Professor Nial Tanvir from the University of Leicester who coordinated efforts to gather data from this spotting using an array of different telescopes on Earth and in orbit.