Your New Year's plan to move more is one of the toughest to stick to, and a group of scientists working with obese(过度肥胖的) mice think they're starting to understand why

    Rather than our sedentary(久坐的) lives causing weight gain, says Alexxai Kraviz, the National Institutes of Health neuroscientist who led the study, changes in brain chemistry after we start gaining weight affect our capacity to move.

    “Obses mice can move just fine,” says Kravitz, who published the work with his team in Cell Metabolism “They just don't.”

    What Kravitz's team found is that the activity of a particular dopamine(多巴胺) receptor linked to movement goes down as mice gain weight on a high-fat diet. So the nice slow down and they move less. And when the researchers restored the activity of that dopamine receptor—DR2—the mice started moving more, even though they were still obese. The team also saw that lean mice missing the DR2 receptor acted like obese mice. This is the target, says Kravitz—restoring that dopamine receptor function. “Maybe 20 or 30 years down the road, we could do that in people,” he says.

    And there is one more thing: The scientists fed normal mice and the mice lacking DR2 the same high-fat diet. Both sets of mice gained weight at the same rate.

    Kravitz says this is important because mice lacking DR2 move less from the get-go, whereas a normal mouse takes a little time to start seeing that dopamine receptor-related loss of exercise. The ability to exercise seems to be disconnected from weight gain, he says.

    “Exercise is a healthy thing to do, but its impact on weight loss has been exaggerated,” he says. “We have to be realistic about the size of the effect of exercise on weight, as opposed to health benefits.”

    Still, before you abandon your New Year's exercise plan, keep in mind that this study was done using a high-fat diet, and not the normal calorie restriction that people maintain when they diet.

    That's a big drawback to the work, says Vicki Vieira-Potter, a University of Missouri physiologist not involved in the study.

    “They feed the mice with high-fat diet, it damages the receptor, and that decreases activity. Those who plan to lost weight should remember high-fat diet is a nice way to cause obesity in the lab, but it's not the same as the normal situation of obesity,” she says.

    Sine also says that a lot of the weight gain in the mice came after they stopped moving around, which indicates that the loss of movement did impact obesity.

    To help the environment, many Americans have made the change from paper and plastic bags to reusable shopping bags.But a report by a Florida newspaper says that reusable shopping bags sold by some supermarkets have high levels of lead(铅), which can be dangerous to humans, especially young children.Now, there's a call for a rethink about the use of reusable shopping bags.

     “When our families go to the store looking for safe and healthy foods, the last thing they should be worrying about is a bag，”Charles Schumer, a government official said.“Quick and complete research will allow everyone to make right decisions.”

    The newspaper bought more than a dozen bags sold at Publix supermarkets from Florida supermarkets to test them for lead.The results showed that certain bags had lead levels that worried health officials.Some bags had enough lead in them to be considered dangerous waste if people were to throw the bags out with other rubbish.Lead in the bags is not likely to move onto food.But over time, paint (油漆) on the bags can break off and the bags can wear out.When this happens, lead can be freed.

    The affected (受影响的) bags were found in Florida.But Publix has more than 1，000 stores across America.Publix says that its bags don't break any laws about lead levels, but that they have asked the makers of the bags to reduce(降低) the lead levels in them.

    The bags with the highest levels of lead had beautiful designs and many pictures.Plain reusable bags without them are found to have little lead.People worried about lead levels in reusable bags can turn to cloth.Paper bags are also a good choice, since paper can be reused.

    It is commonly believed that all over the world,boys and girls attend a mixed school,where they study together. But boys' schools are the perfect place to teach young men to express their emotions and involve them in activities such as arty,dance and music.

    Always boys at single-sex schools were said to be more likely to get involved in cultural and artistic activities that helped develop their emotional expressiveness,rather than feeling they had to correspond to（和…相符）the "boy code" of hiding their emotions to be a "real man".

    Surprisingly,the findings of the study go against received wisdom that boys do better when taught alongside girls.

    George Car,headmaster of Eton,warned that boys were being failed by the British education system because it had become too focused on girls.He criticized teachers for failing to recognize that boys are actually more emotional than girls.

    The research argued that boys often perform badly in mixed schools because they become discouraged when girls do better earlier in speaking and reading skills.

    But in single-sex schools teachers can adjust lessons to boys' learning style,letting them move around the classroom and getting them to compete in teams to prevent boredom,wrote the study's author,Abigail James,of the University of Virginia.

    Teachers could encourage boys to enjoy reading and writing with "boy-focused" approaches such as themes and characters that appeal to them.Because boys generally have more acute vision,learn best through touch,and are physically more active,they need to be given"'hands-on" lessons where they are allowed to walk around."Boys in mixed schools view classical music as feminine（女性的）and prefer the modem genre（类型）in which violence and sexism are major themes,"James wrote.

    Single-sex education also made it less likely that boys would feel that they had to be "masterful and in charge" in relationships."In mixed schools,boys feel forced to act like men before they understand themselves well enough to know what that means,"the study reported.

    The computers changed our lives in the 1980s, the Internet changed our lives in the 1990s, and the robots will change our lives in the new century.

    Do you think there will be robots in people's homes? It's not a dream that every home will have a robot.

    Now, robots are not only able to help people do the housework, they can also help the doctors do the difficult operations, play chess with people, play the piano and so on.

    A new cooking robot is used in Beijing. It can cook all the dishes on the menu, you only need to wait two to four minutes. In the future, the robot will be a nurse, a security guard, or a partner in your life.

    Experts believe robots will be used everywhere from the industrial robots to service robots. In the future, robots will become part of the family, and provide close service for people. We all look forward to the new robot age.

    Arthur Miller(1915-2005) is universally recognized as one of the greatest dramatists（剧作家） of the 20^th century. Miller's father had moved to the USA from Austria-Hungary, drawn like so many others by the “Great American Dream”. However, he experienced severe financial hardship when his family business was ruined in the Great Depression (大萧条时期) of the early 1930s.

    Miller's most famous play, Death of a Salesman, is a powerful attack on the American system, with its aggressive way of doing business and its insistence on money and social status as indicators (标志) of worth. In Willy Loman, the hero of the play, we see a man who has got into trouble with his system, Willy is “burnt out” and in the cruel world of business there is no room for sentiment (情绪): if he can't do the work, then he is no good to his employer, the Wagner Company, and he must go. Willy is painfully aware of this, and at a loss as to what to do with his lack of success. He refuses to face the fact that he has failed and kills himself in the end.

    When it was first staged in 1949, the play was greeted with enthusiastic reviews, and it won the Tony Award for Best Play, the New York Drama Critics' Circle Award, and the Pulitzer Prize for drama. It was the first play to win all the three of these major awards.

    Miller died of heart failure at his home in Roxbury, Connecticut, on the evening of February 10, 2005, the 56^th anniversary of the first performance of Death of a Salesman on Broadway.

    Let's catch a glimpse of the latest inventions this year.

    Parallels lets you use desktop apps on your phone

    You'd think most applications would have created a mobile app by now — but many companies still use desktop apps exclusively. Now Parallels Access lets you access them on your smartphone. All you need to do is download the app, then connect Parallels' Applification™ to your computer, so you can access important files and other apps with a single click. You can easily use your apps in full-screen mode, using intuitive(直观的) touch controls to work faster than before.

    Usually, Parallels Access is $19.99, but you can get it now for $9.99.

    Take your lighting to the next level with this smart switch

    You probably don't spend a lot of time thinking about your home's lighting, but it's important: the way that you control your lighting affects the environment (and your electric bill).

    This WiFi wall switch is controlled via a companion app on your smartphone, so you can control connected lights or ceiling fans from anywhere.

    Usually, the Meross WiFi Wall Light Switch costs $45.99, but right now it's on sale for $39.99 .

    Shoot beautifully clear videos with this smartphone gimbal

    If you're interested in shooting professional-quality videos and photos, you don't have to spend a fortune to take a beautifully composed shot: just use this Rigiet Smartphone Gimbal instead.

    A gimbal is a support for your camera (in this case, your smartphone) that allows it to pivot（移动）, and automatically detect and adjust to the position that you want to film in. Unlike any other camera hardware you might own, this one comes with its own accompanying app.

    Usually, this Rigiet Smartphone Gimbal is $269, but you can get it now for $109.99.