The more hours that young children spend in child care, the more likely they are to turn out aggressive and disobedient by the time they are in kindergarten, according to the largest study of child care and development ever conducted. Researchers said this correlation (相关性) held true regardless of whether the children came from rich or poor homes, were looked after by a relative or at a center, and whether they were girls or boys.

    What is uncertain, however, is whether the child care actually causes the problem or whether children likely to turn out aggressive happen to be those who spend more hours in child care. It also remains unclear whether reducing the amount of time in child care will reduce the risk that a child will turn into a mean person. What's more, quality child care is associated with increased skills in intellectual ability such as language and memory, leading some academics to suggest that child care turns out children who are “smart and naughty”.

    The government-sponsored research, which has tracked more than 1,300 children at 10 sites across the country since 1991, is bound to cause the debate over child care again: How should people balance work and family? And how should parents, especially mothers. Resolve the demands that are placed on them to be both breadwinners and supermoms?

    That debate was already on display at a news briefing yesterday, where researchers themselves had different opinions about the data and its implications (含义). “There is a constant relationship between time in care and problem behavior, especially those involving aggression and behavior,” said Jay Belsky of Birkbeck College in London, one of the lead investigators of the study who has previously annoyed women's groups because of his criticisms of child care. “On behalf of fathers or mothers?” interrupted Sarah Friedman, a developmental psychologist at the National Institute of Child Health and Human Development (NICHD) and one of the other lead scientists on the study. “On behalf of parents and families,” responded Belsky.

    “NICHD is not willing to get into policy recommendations.” said Friedman, contradicting her colleague. “There are other possibilities that can be entertained. Yes it is a quick solution—more hours in child care is associated with more problems. The easy solution is to cut the number of hours but that may have implications for the family that may not be beneficial for the development of the children in terms of economics.” In an interview after the briefing, Friedman said that asking parents to work fewer hours and spend more time with their children usually meant a loss of family income, which adversely(不利地) affects children.

    Scientists said that the study was highly reliable. But the researchers said they had no idea whether the behavioral difficulties persisted as the children moved to higher grades.

    Custom tattooed fish (纹身鱼) may be big sellers at markets, but an animal expert say it is a cruel and potentially lethal practice.

    In Laitai Flower and Fish Market near the Lufthansa Center in Beijing, four of over 20 fish stores sell marine ornamental fish that are tattooed using laser (激光) guns with beautiful images in order to make them more attractive to customers. Many people just love these kinds of fish, which gives them a unique visual impression. The price of these fish ranges from 50-100 yuan. Some customers are willing to pay an additional 100 yuan to have Chinese characters tattooed on to the fish. The most popular characters are “zhaocai” (attracting fortune) and “fu” (blessing). The color of tattooed fish won't fade away, and the fish can be cared for as regular fishes:

    But Ye Zhenjiang, a professor from the Ocean University of China, said “the practice would damage a fish's mackerel scale, which is its protective layer. Although I haven't done any research on the impact of the laser on mackerel scale, it is obvious that the mackerel scale may be infected or even destroyed under the exposure of laser,” Ye said. “It's like tattooing a human being's body, and it breaks the physiological balance of the fish and damages: the skin's protective surface, It may even cause death among fishes which have thin mackerel scale.”

    A specialist in aquatic(永生的) animal study surnamed Xu, from the Beijing Fisheries Research Institute, said, “We have no specific regulations to prevent fish from being tattooed. An official surnamed Bai from the Fishery Surveillance and Administration Bureau(FSAB), said there is no study showing that the laser threatened a fish's health. He said a regulation on small animal protection, to be passed in the near future, doesn't include regular aquatic animals. He said the institution is only responsible for aquatic animals that are on the verge of extinction. He said tattooed fish are mainly from south China's Guangdong province because Beijing does not have the laser technology to tattoo a fish.

    “It's too brutal to tattoo pictures or characters on fishes, even if it makes them more beautiful,” many tropical fish buyers told METRO yesterday. “We would never buy fish like that and we prefer them with natural beauty.”

    When I was a boy, I was always happy to see those little brown coins. After years I was still very happy to pick up pennies on the ground, I usually saved them up. I usually bought a pack of gum or a bag or chips when it was enough. After growing up, I hears a story about coins. It was said that our loved people sometimes would leave pennies on the ground in front of us. People wanted to show us that we were loved and watched over kindly. I never doubted that story even as an adult. It is difficult for me to find a lot of money on the ground, but pennies are there all the time. Maybe that is why I still enjoy seeing them and picking them up, no matter how dirty or old they are.

A few months ago, I was walking to the local post office to mail a letter. As I entered the room, I saw not one, not two, but four pennies shining in the sunlight. I smiled and picked them up. I kept them in my hands as I walked in the post office. "Four is Ok," an office said to a lady. The lady began searching her purse. Her face went red. I understood what had happened. I laughed to myself at this surprising moment. I placed my pennies on the desk before her. The smile I got in return was worth a thousand dollars.

    The coins weren't so valuable to me, but they did matter to her. I just performed a little kindness. I was happy.

    Here's an idea whose time has come: A flu shot that doesn't require an actual shot.

    For the first time, researchers have tested a flu vaccine patch (疫苗贴) in a human clinical trial and found that it delivered as much protection as a traditional injection with a needle. Doctors and public health experts have high hopes that it will increase the number of people who get immunized (免疫的) against the flu.

    Seasonal flu is responsible for up to half a million deaths around the world each year according to the World Health Organization. A team led by Georgia Tech engineer Mark Prausnitz has come up with an alternative method that uses “microneedles”. These tiny needles are so small that 100 of them, arranged in order on a patch, can fit under your thumb (拇指).Yet they're big enough to hold vaccine for three types of flu.

    None of the study volunteers had serious side effects. The groups that got patches had mild skin reactions that were not seen in the regular needle group, while the volunteers in the regular needle group were more likely to experience pain. Overall, 70 percent of the volunteers who got vaccine patches said they'd rather use them again than get a traditional flu shot. The study authors declared it a success on all fronts.

    The biggest beneficiaries could be people in low- and middle-income countries, where flu vaccines are hard to come by. Reducing pain is nice, but other benefits—the patch costs less，is easier to transport, doesn't require refrigeration, can be self - administered and doesn't cause waste of needles—are even better.

    “Microneedle Patches have the potential to become ideal candidates for vaccination programs,” wrote Katja Hoschler and Maria Zambon of Public Health England.

    Why does time seem to fly by faster as we get old? You've got your aging brain to blame. This is likely due largely to the physical changes of our nerves and neurons (神经元). New research suggests 'rapid fire' abilities of the young brain allow us to process more information during youth, causing the days to seem longer earlier in life. However, as we get old, researchers say the older brain takes more time to process information.

    The new finding put forward by a Duke University researcher was published in a paper in the journal European Review this week According to Adrian Bejan, the J. A Jones Professor of Mechanical Engineering at Duke, the physical changes of our nerves and neurons play, a major role in our perception (知觉) of time as we get old. Over the years these structures become more complex and eventually begin to degrade.

    "Little babies, for example, move their eyes much more often than adults because they're processing images at a faster rate," Beian says, For older people, this means fewer images are being processed in the same amount of time, causing experiences to seem as though they're happening more quickly.

There are so many choices when you go shopping. You have to check the sell — by dates so that you know how long you can store and use the food you are purchasing.

But do you know that the best sell — by dates on food packaging don't really tell you if the food is safe to eat. The food may not last as long as it says if it isn't stored correctly at any point of the distribution chain. Now there is food packaging that can detect and change colors if the food has gone bad.

Each American wastes 103 pounds of spoiled food out of the refrigerator every year. The new smart packaging from Primitives Biodesign—a new company that operates out of a lab at Indibio, a biotech accelerator in San Francisco-can help to reduce this huge waste of food.

The basic material that doesn't contain sensing material is made from algae and can block oxygen more effectively than regular film, so the food stays fresher for a longer time. Since it is made from a natural substance, it can also break down in nature.

Making the film smart is the thorny part. Luckily, the team managed to use a process that is like the way nature responds to changes in the environment. The mechanism responds like the way flowers emit compounds to change colors.

"It could be supplement packaging that indicate when it's been tampered with by changing color to tell you that it's no ledger safe," says Kan. She explained that the new packaging can be used on food products to fell if the food has turned bad before someone has to smell or taste it.

The company has proven in lab tests that the technology works and now they are working on how to develop commercial uses for it. The added safety features will come out later. Helping to control food waste in products like meat or cheese which have high greenhouse gas emissions will also help to reduce climate change.