Lab Report: Health, Science and Medicine

SCIENCE

Bee Deaths Solved?

It's a scary sight for beekeepers: An empty hive, devoid of its busy workers and the usual hubbub of honeymaking that signifies a healthy colony. But since late 2006, keepers across the U.S. have lost thousands of colonies and billions of bees to a mysterious condition dubbed colony-collapse disorder. Stricken adult bees inexplicably fled their cozy honeycomb, ostensibly in search of pollen, and failed to return, having died alone somewhere in the wilderness. Now scientists believe they have identified the culprit: a combination of viral and fungal infections.

The microbial one-two punch emerged after researchers in Montana, in conjunction with the U.S. Army, conducted an extensive analysis of proteins extracted from collapsed hives and the carcasses of affected bees and compared them with those from healthy hives. It still isn't clear whether the infections are killing the bees or are merely a side effect of the true cause. But for the time being, they are the strongest leads that keepers have--and their best targets for treatment. The virus can be eradicated only by culling infected hives, but the fungus can be controlled with commercially available antibiotics.

CHILD HEALTH

Screen Time May Trigger Kids' Psychological Ills

Numerous studies have linked the sedentary hours spent in front of a computer or television set with obesity in young children. Now research is connecting screen time with mental-health problems too.

In a study of 1,000 children ages 10 and 11, researchers tracked kids' activity levels and used questionnaires to gauge their screen-viewing time as well as their mental health and social behavior. Those who spent more than two hours a day in front of a screen were more likely to have emotional difficulties, hyperactivity or problems relating to other people, compared with kids who had less screen time. And while children who were more physically active overall reported fewer problems than their sedentary peers, increasing exercise levels did not mitigate the social and behavioral difficulties associated with excessive TV or computer use.

The results, say the researchers, reinforce the importance of limiting screen time for children. (The American Academy of Pediatrics advises no more than two hours a day.) The scientists note that the drop in physical activity among youngsters may also be linked to a more general decrease in living space--which for kids means less space to play--that tends to promote low-activity pursuits such as watching TV or using a computer.

FROM THE LABS

The Heavy Toll of Light Nights

Staying up late can have many health consequences, including weight gain. In a recent study, mice exposed to constant overnight light gained 50% more weight than mice whose nights were dark, even without any change in diet or activity level. The light, it seems, pushed the mice to eat at the wrong times, when they were more likely to pack on pounds.

Smoking's Smoking Gun