Sun-Powered Craft Launched

The world's first solar sail spacecraft was launched yesterday from a Russian submarine under the Barents Sea, but concern grew about whether it safely reached orbit as hours passed without a signal.

Cosmos 1, a $4 million experiment intended to show that a solar sail can make a controlled flight, was launched at 12:46 p.m. Pacific time (3:46 EDT) , and initial data reception was followed by silence.

Data stopped during a pass over a portable ground station on Russia's Kamchatka peninsula about the time the rocket's final stage would have ignited, officials said.

There was no signal on later passes over stations in the Pacific Ocean, the Czech Republic and two in Russia. None of those passes, however, were optimal for receiving signals.

Scientists expect Cosmos 1 to orbit Earth once every 101 minutes and operate for at least a month.

The non-governmental project was organized by the Planetary Society, based in Pasadena, Calif.

For Kids, an Hour of Activity

Children should get an hour of exercise over the course of each day, a panel of national obesity experts has concluded, seeking to end confusion on the matter.

"Physical activity is essential for health. This just puts a number on the amount of physical activity children should receive or shoot for," said William Dietz, director of nutrition and physical activity for the Centers for Disease Control and Prevention, which funded the panel.

The committee was created to cut through conflicting advice on children's exercise -- 27 groups have made their recommendations.

The panel reviewed more than 850 studies on child physical activity and found that most recommended 30 to 45 minutes of continuous activity. The panel decided that 60 minutes of exercise was more appropriate, because children typically are active in "fits and spurts" rather than in a continuous manner.

Study: Antibiotics Overused

Lower respiratory tract infections that trigger coughing fits and fever usually clear up on their own, yet millions of dollars are wasted prescribing antibiotics to hacking patients, researchers said yesterday.

A study of more than 500 patients suffering from acute bronchitis or pharyngitis found the bouts of coughing lasted an average of nearly 12 days after the doctor visit whether or not antibiotics were prescribed immediately.

Overuse of antibiotics has become a worrisome trend because it renders some drugs ineffective as infectious bugs mutate, requiring doctors to deploy stronger antibiotics.

Antibiotic prescriptions for lower respiratory tract infections account for 55 percent of excess prescriptions in the United States, wasting about $726 million a year, wrote study author Paul Little of the University of Southampton in England

There are some more severe infections that antibiotics can help, but the drugs are routinely overprescribed for deep coughs and flu associated with lower respiratory infections because patients often ask for them, the researchers said.

-- From News Services