HIV moves/ Mir's crash/ CFCs waning

theoretically ...

Would you volunteer to be injected with HIV? Fifty doctors and public health advocates in Chicago said they would risk their lives to test an Aids vaccine using a live - weakened - strain of the human immunodeficiency virus. The experiment needs approval first from the US's National Institutes of Health, but even so one must admire the bravery of those involved.

David Ho, of New York's Aaron Diamond Aids Research Center, says protease inhibitors - the latest wonder drug against HIV - could soon be a once- a-day therapy, instead of dozens of pills many times a day. Trials involving patients could start within six months. "[We're] at the endgame," Ho said, "but the endgame could be as tough as any part of the game." Maybe those 50 volunteers can stand down.

The Mir space station's central computer crashed again yesterday for the third time in three weeks - and the US space shuttle Atlantis is to dock with the Russian space station on Saturday. More worrying, the crew saw "brown drops" coming out of the engines during rotation. If the system crashes on docking, there could be a real-life rather than a software crash. No suggestion, though, that the shuttle astronauts are taking along a replacement laptop or even an abacus for Thursday's launch.

"I'm amazed that the protocol worked." Happy words from Mario Molina, one of the scientists who in the mid-Seventies pointed out the CFC threat to the ozone layer. The Montreal Protocol banning them is 10 years old, and Molina, of MIT, told Nature: "The concentration of chlorine getting into the stratosphere has levelled off and is starting to decrease."

What causes gamma-ray bursters? These intense, short-lived bursts of energy, appearing to come from outside the Milky Way, may be caused when a neutron star orbits a black hole, stripping away the orbiting star's matter chunk by chunk. That's the suggestion of physicists Wlodzimierz Kluzniak and William Lee, at the University of Wisconsin-Madison.