Discoveries

DISCOVERIES

July 15, 2005

Did you know ...

Within a week or so of being bitten by a tick carrying Lyme disease, 80 percent of people develop a red, slowly expanding bull's-eye rash. The rash can be accompanied by fatigue, fever, headache, stiff neck, muscle aches and joint pain.

- Centers for Disease Control and Prevention

In Brief

Parkinson's drugs and compulsive gambling

A handful of drugs commonly prescribed for Parkinson's disease can turn a small proportion of patients into compulsive gamblers in as little as a month, according to a study published Tuesday in the journal Archives of Neurology.

The study is the one of several to show the link and confirms that the drug pramipexole - widely prescribed under the brand name Mirapex - is the most likely to cause the rare side effect.

Dr. M. Leann Dodd, a psychiatrist at the Mayo Clinic in Rochester, Minn., and her colleagues studied 11 patients who became compulsive gamblers - nine of whom were taking pramipexole. Two others took a similar drug, ropinirole. Some of the patients gambled away up to $1,500 a day, according to the study. Losses over a six-month period ranged from $2,500 to $200,000.

Dodd emphasized that the incidents are rare and that the drugs are beneficial for improving mobility and alleviating the uncontrolled trembling associated with Parkinson's. "People need to understand that this is a pretty unusual condition," she said. "These are still very effective treatments for Parkinson's disease."

Autism cases level off, California officials say

New cases of autism in California, which have been skyrocketing for more than a decade, have leveled off and might be declining, according to new data compiled by the state Department of Developmental Services.

Although the total number of autistic children receiving special education services from the state continues to grow - bringing the current total to 28,046 - the rate of increase peaked in 2002 and has dropped slightly since then.

The findings are important because California has the best reporting system for autism in the United States and generally is considered a bellwether for the rest of the country.

Experts do not have a good explanation for the slowdown in new cases.

"Perhaps whatever caused [the number of cases] to go up - environmental insult, or whatever - is no longer present," said Dr. Robert Hendren, executive director of the University of California Davis MIND Institute.

Parent activist Rick Rollens of Sacramento said that the trend roughly corresponds to the removal of mercury preservatives from pediatric vaccines. Many activist groups say mercury in the vaccines caused the sudden increase in autism cases. Federal scientists, however, have said that the evidence does not support such a link.

- From wire reports

Like the view from Tatooine

Imagine waking up to not one, but three rising suns each day - one yellow like our own but much closer and bigger in the sky, the others red and orange and far smaller and more distant.

"It would be a pretty weird view," said Maciej Konacki, a planetary scientist at the California Institute of Technology, who has detected a planet 149 light years from Earth with just such a view.

Konacki, who describes his discovery in this week's issue of the journal Nature, likes to call it the first in a new class of "Tatooine planets." It's a reference to Luke Skywalker's home world in the first Star Wars movie, which was depicted under twin suns.

Astronomers already know of one other planet in a triple star system. But those stars, he said, are so far apart - 640 times the distance from the sun to the Earth - that it doesn't really count. His is the first planet found in a "close triple" system like this one, where all the suns are clustered within six to 18 times the sun-Earth distance.

Konacki's new planet is a "hot Jupiter," a gas giant orbiting 25 times closer to its main star than Earth is to the sun. It's so close that a year on that planet lasts just 3 1/2 Earth days.

The two other suns orbit each other at a distance from the main star similar to that of Saturn from our sun. The pair then circles the main star every 26 years.

Known collectively as HD 188753, the system's component stars are so close to each other they look like one star in telescopes.

Konacki developed a new observational technique that allowed him to distinguish the light spectrum emitted by the main star from those of its twin companions. He was then able to precisely measure their relative velocities. Subtle fluctuations in the speed of the main star then revealed the gravitational influence of a large, nearby but unseen planet.

The discovery challenges scientists' current theories about planet formation, which would rule out formation of a "hot Jupiter" planet so close to a parent star in a multiple system like HD188753. "That's a problem," Konacki said.

Another mystery is whether life could ever evolve on a planet with three suns to a point where it could produce someone to enjoy the view.

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