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.

    If you will be cycling, you will need to know what these traffic signs and signals mean.

    A sign like this one means that there is a bike lane（道）. If there is a bike lane, you are required to use it. If there is not a bike lane, you should ride with traffic as far to the right side of the road as possible.

    When the signal light turns green, cars go. When you cross the street at a signal light, you should wait for the walk signal. Be sure to look carefully to the left, right and left again, before crossing the street.

    When the signal light turns yellow, car drivers should slow down and prepare to stop. You should not cross if the light is yellow. The light is about to turn red, and cars will enter the intersection(十字路口).

    This signal is the WALK sign. It has a picture of a person walking instead of using the word WALK.

    This signal is the DON'T WALK sign. It is part of the signal with the picture of a person walking. This is a picture of a red hand, meaning you should stop. You should wait to cross the street until the green picture of the person walking is showing.

    Car drivers and bikers must come to a complete stop at STOP signs.

    A yield sign means to slow down and be ready to stop. If there are pedestrians（行人）or vehicles in or nearing the intersection, you must stop. If there is no traffic in or nearing the intersection and it is safe, you may go through.

    This sign means you are coming to a crosswalk. Car drivers and bikers must stop to allow people in the crosswalk to cross the street.

    'Kangaroo mothering' helps boost a child's health and intelligence

    “Kangaroo mothering”, the practice of continuous skin-to-skin contact with a newborn baby, results in healthier, more intelligent and successful children, a new study finds.

    A 20-year follow-up research found that those brought up in the kangaroo method scored higher in IQ tests and earned 53% more. They were also found to be less likely to have behavior problems than babies in a control group.

    Followers of the method nest their kids in a “kangaroo” position on their chest as soon as possible after birth. Both mother and baby are supposed to go home as quickly as possible.

    The technique is often used in cases of premature birth (早产). In such cases, the trained mother acts as the child's main source of stimulation (刺激) and food, in the form of breast feeding. Between 1993 and 1996, a group of more than 700 prematurely born babies in Columbia were, on the basis of random selection, placed either away from mother or were raised using the kangaroo method. Two decades later, a follow-up survey funded by the Canadian Government has shown that those who went through the latter method benefited by comparison.

    Published in the journal Paediatrics, the research shows that kangaroo mothering offered significant protection against early death, with a 3.5% death rate compared to a 7.7% rate in the control group. IQ test also showed a small but significant advantage of 3.5% compared to other infants. 

    Lead researcher Dr Nathalie Charpak, of the Kangaroo Foundation in Bogota, said the method has “significant, long-lasting social and behavioral protective effects”. “We firmly believe that this is a powerful, efficient, scientifically based healthcare intervention that can be used in all settings, from those with very restricted to unrestricted access to healthcare.”

    The study also found that, compared with babies in the control group, those raised in the kangaroo method went on to develop bigger brains, with significantly larger volumes of gray matter.

    You signed up for soccer, and played every game of the season. Sure, you're not the best player on the team, but most days you gave it your all. Do you deserve a trophy (奖杯)?

    If the decision is up to Carol Dweck, the answer would likely be no. She's a psychology professor at Stanford University, California. She says a player doesn't have to be the best to get a trophy. But those who receive an award should have to work for it. She suggests trophies go to the most improved player, or the one who contributed most to the team spirit, as well as to those who play the best.

    “The trophy has to stand for something，” Dweck told TFK. “If we give a trophy to everyone, then the award has no value.” Dweck argues that giving kids trophies for particular reasons, such as improving in a sport, and teaches kids that adults value hard work and trying our best.

    Others say that there's no harm in giving awards to all kids who play a sport, regardless of how they played or whether or not they improved.

    “I think we should encourage kids' participation in sports，” says Kenneth Barish, a psychology professor at Weill Cornell Medical College, in New York City. “A trophy is one way to encourage kids' efforts.”

    Barish argues that when we only single out the best or even the most improved players with a trophy, we are teaching kids the wrong lesson. We are sending the message that winning is everything. “Winning is only part of the equation (等式)，” Barish told TFK.“Playing sports also teaches kids about teamwork and the importance of exercise.”

    There will be plenty of opportunities for kids to learn about competition as they get older, says Barish. They'll soon realize that only one soccer team wins the World Cup and only one football team wins the Super Bowl. For now, he thinks there's nothing wrong with letting all kids who play a sport feel like winners. That means trophies for everyone.

    Eco-friendly Vauban, lied in the southwest part of Germany, has everything－tree-lined streets, perfect houses－but it's missing one urban feature of the last 100 years or so: the car. And Vauban residents(居民) don't mind one bit. Vauban doesn't ban cars entirely. Rather, it just tries to reduce the use of cars by creating “parking-free” and “car-free” living. In Vauban, parking spots are a no-no private property(私人财产). Cars can only be parked in public parking lots, so living without a car saves residents the cost of parking in the public lot. Cars also are prevented from using certain roads and must stick to strict speed limits. With these limitations, fewer than 20 percent of residents own cars. Without cars, bikes are almost religion in this small town. Kids pick them up even before they can ride one. Vauban is about much more than just using two wheels instead of four. In Vauban , residents ride bikes and even receive money from the electric company for selling electricity back to the power grid (电网系统). It's an environmentally-friendly city of the future, with organically grown food, renewable energy, and carbon-neutral homes. And now, with a population of 5,500, it's attracting attention from around the world. Can an eco-friendly city like Vauban be a model for Americans to stop their over-reliance on the cars?

    Sometimes when I watch a news report what's in the back of my mind is what isn't being reported or stressed. While this eco-friendly city is inspiring in that it shows residents getting exercise and fresh air through the majority use of bicycles, as well as good old fashioned walking, common sense would tell you that even for a place like Vauban, Germany, it owes its existence to the cars.

    Do you think that bicycles were able to transport all the construction materials that were needed to build and maintain the eco-friendly homes and businesses in Vauban? It took cars to help build this utopia. It's one of the paradoxes of life that sometimes in order to get away from relying on something like the car, you actually have to rely on that very thing at the beginning and into the foreseeable future to some degree.

    I myself haven't owned a car for more than 14 years, and mostly get around town running, walking, or using public transportation. There are times I wish I had one, since it would make many things easier, but overall I'm glad not to have to deal with the headaches of owning a car, which caused me to get rid of it in the first place. And all the walking and running has helped to keep me fit and healthy.

    To get even close to being like eco-friendly Vauban, Americans will need to absolutely change the way they live. Commuting(乘车上下班) patterns will have to change, public transportation will have to be invested in, and so on. And though ending our love affair with the car will be impossible during my lifetime, we may at least start to see more Vauban-like areas in the USA.

    We can hope that Americans will consider using their feet more to get around, cutting down on pollution, and giving themselves some more exercise.

    The Huaqing Palace Heritage Site

    Address: At the foot of Lishan Mountain in Lintong, 30 kilometers east of Xi'an.

    Opening hours: From March to November: 7:00-18:00;

    From December to February: 7:30-18:30.

    Bus routes: 914, 915, U5, and 306.