Over the last seven years, most states have banned texting by drivers, and public service campaigns have tried a wide range of methods to persuade people to put down their phones when they are behind the wheel.

Yet the problem, by just about any measure, appears to be getting worse. Americans are still texting while driving, as well as using social networks and taking photos. Road accidents, which had fallen for years, are now rising sharply.

That is partly because people are driving more, but Mark Rosekind, the chief of the National Highway Traffic Safety Administration, said distracted (分心) driving was "only increasing, unfortunately."

"Big change requires big ideas." he said in a speech last month, referring broadly to the need to improve road safety. So to try to change a distinctly modern behavior, lawmakers and public health experts are reaching back to an old approach: They want to treat distracted driving like drunk driving.

An idea from lawmakers in New York is to give police officers a new device called the Textalyzer. It would work like this: An officer arriving at the scene of a crash could ask for the phones of the drivers and use the Textalyzer to check in the operating system for recent activity. The technology could determine whether a driver had just texted, emailed or done anything else that is not allowed under New York's hands-free driving laws.

"We need something on the books that can change people's behavior," said Félix W. Ortiz, who pushed for the state's 2001 ban on hand-held devices by drivers. If the Textalyzer bill becomes law, he said, "people are going to be more afraid to put their hands on the cell phone."

Researchers say they have translated the meaning of gestures that wild chimpanzees (黑猩猩) use to communicate. They say wild chimps communicate 19 specific messages to one another with a "vocabulary" of 66 gestures. The scientists discovered this by following and filming groups of chimps in Uganda, and examining more than 5,000 incidents of these meaningful exchanges.

Dr Catherine Hobaiter, who led the research, said that this was the only form of intentional communication to be recorded in the animal kingdom. Only humans and chimps, she said, had a system of communication where they deliberately sent a message to another group member.

"That's what's so amazing about chimp gestures," she said. "They're the only thing that looks like human language in that respect. ”

Although previous research has shown that apes and monkeys can understand complex information from another animal's call, the animals do not appear to use their voices intentionally to communicate messages. This was a significant difference between calls and gestures, Dr Hobaiter said.

Chimps will check to see if they have the attention of the animal with which they wish to communicate. In one case, a mother presents her foot to her crying baby, signaling:" Climb on me. " The youngster immediately jumps on to its mothers back and they travel off together. "The big message from this study is that there is another species (物种) out there. that is meaningful in its communication, so that's not unique to humans," said Dr Hobaiter.

Dr Susanne Shultz, an evolutionary biologist from the University of Manchester, said the study was praiseworthy in seeking to enrich our knowledge of the evolution of human language. But, she added, the results were "a little disappointing".

"The vagueness of the gesture meanings suggests either that the chimps have little to communicate, or we are still missing a lot of the information contained in their gestures and actions," she said. "Moreover, the meanings seem to not go beyond what other animal convey with non-verbal communication. So, it seems the gulf remains. "

    For those who can stomach it, working out before breakfast may be more beneficial for health than eating first, according to a study of meal timing and physical activity.

Athletes and scientists have long known that meal timing affects performance. However, far less has been known about how meal timing and exercise might affect general health.

    To find out, British scientists conducted a study. They first found 10 overweight and inactive but otherwise healthy young men, whose lifestyles are, for better and worse, representative of those of most of us. They tested the men's fitness and resting metabolic (新陈代谢的) rates and took samples (样品) of their blood and fat tissue.

    Then, on two separate morning visits to the scientists' lab, each man walked for an hour at an average speed that, in theory should allow his body to rely mainly on fat for fuel. Before one of these workouts, the men skipped breakfast, meaning that they exercised on a completely empty stomach after a long overnight fast (禁食). On the other occasion, they ate a rich morning meal about two hours before they started walking.

Just before and an hour after each workout, the scientists took additional samples of the men's blood and fat tissue.

    Then they compared the samples. There were considerable differences. Most obviously, the men displayed lower blood sugar levels at the start of their workouts when they had skipped breakfast than when they had eaten. As a result, they burned more fat during walks on an empty stomach than when they had eaten first. On the other hand, they burned slightly more calories (卡路里), on average, during the workout after breakfast than after fasting.

    But it was the effects deep within the fat cells that may have been the most significant, the researchers found. Multiple genes behaved differently, depending on whether someone had eaten or not before walking. Many of these genes produce proteins (蛋白质) that can improve blood sugar regulation and insulin (胰岛素) levels throughout the body and so are associated with improved metabolic health. These genes were much more active when the men had fasted before exercise than when they had breakfasted.

The implication of these results is that to gain the greatest health benefits from exercise, it may be wise to skip eating first.