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.

    Daylight-powered germ-killing equipment（杀菌设备）may someday help protect health workers from deadly virus like Ebola virus. That is a finding from a study published in the journal Science Advances.

    Study organizers say they've developed membranes（薄膜）that produce very small amounts of hydrogen peroxide（过氧化氢）when left in daylight. Membranes are thin plastic, structures that can serve as barriers. They let some things pass through, but other things art blocked. Hydrogen peroxide, a liquid sold in drug stores, works as a disinfectant（杀菌剂）.

    Nearly 500 health workers were infected and died in 2014 when Ebola spread through parts of West Africa. Caregivers wear full-body protective suits when they come into contact with patients with infectious diseases. But the process of removing the suits is a time when infection can spread if the surface is covered with virus. “If there's any live bacteria or virus on the surface, it's still transmissible and could cause infection,” said Gang Sun of the University of California. He is one of the researchers that worked to develop membranes that could cover the outside of protective equipment.

    When the chemical molecules（分子）on the surface of these membranes are put in sunlight, they react with oxygen in the air to produce small amounts of hydrogen peroxide. Gang Sun explains that the process creates less hydrogen peroxide than what you would use to remove dirt on clothing, for example. But it is still enough to kill organisms.

    Rohan Tikekar is a food scientist with the University of Maryland. He described the development as “quite novel,” or new and different, Tikekar was not involved with the recent study. He said others have developed materials that produce disinfecting chemicals. But most only work under high-energy ultraviolet（U V）light, and not usual daylight. The new membrane also works in the dark for at least an hour or two because of chemical properties that can recharge its germ-killing powers. Tikekar called that an important improvement.

    Gang Sun said the new membranes, though still Far from perfect could be used for things other than protective equipment for health workers. They could also be added to packaging for fruits and vegetables to keep foods fresher and reduce the risk of being polluted. Some versions of the material use natural chemicals' Sun says that one of the next steps is to make it safe to sat

    Obama, Lady Gaga and Steve Jobs—what do they have in common? They are, of course, all Americans. And according to a survey by social networking site baidu.com, they all best illustrate the word “cool”.

    But just what does it mean to say someone is “cool”? Most would answer that it is something to do with being independent-minded and not following the crowd.

    Yale University art professor Robert Farris Thompson says that the term “cool” goes back to 15th century West African philosophy. “Cool” relates to ideas of grace under pressure.

    “In Africa,” he writes, “coolness is a positive quality which combines calmness, silence, and life.”

    The modern idea of “cool” developed largely in the US in the period after World War II. “Post-war 'cool' was in part an expression of war-weariness… it went against the strict social rules of the time,” write sociologists Dick Pountain and David Robins in Cool Rules: Anatomy of an Attitude.

    But it was the American actor James Dean who became the symbol for “cool” in the hugely successful 1955 movie Rebel without a Cause. Dean plays a tough guy who disobeys his parents and the authorities. He always gets the girl, smokes cigarettes, wears a leather jacket and beats up bullies. In the movie, Dean showed what “cool” would mean to American young people for the next 60 years.

    Today the focus of “cool” has changed to athletics stars. Often in movies about schools, students gain popularity on the athletics field more than in the classroom. This can be seen quite clearly in movies like Varsity Blues and John Tucker Must Die.

But many teenagers also think being smart is cool. Chess and other thinking games have been becoming more popular in schools.

    “Call it the Harry Potterization of America—a time when being smart is the new cool,” writes journalist Joe Sunnen.

    China is known as a state of manners and ceremony. Many proverbs have been passed down from generation to generation such as "polite behavior costs nothing" or "showing respect each other" and so on. For instance, there is an interesting short story. Once upon a time, a man went on a long tour to visit his friend with a swan as a gift. But it escaped from the cage on the way. Though he tried hard, he got hold of nothing but a feather. Instead of returning home, he continued his journey with the swan feather. When his friend received this unexpected gift, he was deeply moved. And the saying "The gift is nothing much, but it's the thought that counts." was spread far and wide.

    Chinese used to cup one hand in the other before the chest as a greeting. This tradition has a history of more than 2, 000 years and nowadays it is seldom used except in the Spring Festival. And shaking hands is more popular. Bowing, as to show respect to the higher level, is often used by the lower like subordinates(下级), students, and attendants. But at present Chinese youngsters prefer to simply nod as a greeting.

    When you start a talk with a stranger, the topics such as weather, food, or hobbies may be good choices to break the ice. For a man, a chat about sports, stock market or his job can usually go on smoothly. Similar to Western customs, you should be careful to ask a woman private questions. However, relaxing talks about her job or family life will never put you into danger. Though Chinese are said to be implicit(含蓄的), they are actually humorous enough to be pleased about the jokes of Americans.

    A large number of people enjoy listening to various types of music while they paint, write, or draw. Many believe that music helps creativity.

    However, an international study conducted by English and Swedish researchers is challenging that opinion. Psychologists from Lancaster University, The University of Gävle, and The University of Central Lancashire say that their findings show music actually blocks creativity.

    To come to their conclusions, researchers had participants( 参与者) complete verbal insight problems designed to inspire creativity while sitting in a quiet room, and then again while music played in the background. They found that background music “badly affected” the participants' ability to complete tasks related to verbal creativity.

    The tasks were simple word games. For example, participants were given three words, such as dress, dial, and flower. Then, they were asked to find a single word related to all three that could be combined to form a common phrase or word. The single word, in this case, would be "sun" (sundress, sunflower, etc).

    Participants completed the tasks in either a quiet room, or while exposed to three different types of music; music with unfamiliar words, instrumental music, or music with familiar words. "We found strong evidence of damaged performance when playing background music in comparison to quiet background conditions," says co-author Dr. Neil McLatchie of Lancaster University.

    To conclude, the findings challenge the popular view that music encourages creativity, and instead prove that music consistently disrupts creative performance in dealing with problems.

    Last night, when I went to see my grandmother, she was sitting alone at the nurse station with her word search book. My grandmother was sitting at the desk with her book but no pencil just staring at the letters as if she was trying to find the word. I came to her and said hello.

    Usually, she at least knows I am connected to her somehow but this time, she looked at me with doubt. I introduced myself and told her that I was her granddaughter. "I don't know who you are," she said." Do you want to go outside?" I asked. "okay," she said.

    We got her things and I wrapped it all in a blanket we would use as a tablecloth. I asked her if she could hold it while I pushed her wheelchair and held her cup of tea.

    She held her hands out and I placed the cloth bundle (捆) on her lap. I put the cloth on the table and she helped smooth it down-then I put the rest of the items on the cloth.

    Now she was just staring at me as if confused, as if trying to figure me out. "Do you know who I am?" I asked. She said, "I don't really know." "I am your granddaughter," I said. "I am not sure what that is. I don't know, I don't know you," she said.

    I think of my friend whose mother has not known him for years, has no recollection (记忆), and doesn't speak any more. It is a painful sight for all those living who remember. I am grateful that my grandmother is still so present. I have a sinking feeling that our days are numbered.

    For now, she is still here, still says thank you, and still loves me from a deep and secret place. Tomorrow, I will see her and she may or may not know me-and that will be okay. I still know her.