Sleep deprivation(缺失)is an important hidden factor in lowering the achievement of school pupils, according to researchers carrying out international education tests.

    It is a particular problem in richer countries with sleep experts linking it to the use of mobile phones and computers in bedroom late at night. Sleep deprivation is such a serious problem that lessons have to be dragged down to a lower level to suit sleep-deprived learners, the study found. The international comparison, carried out by Boston College, found the United States to have the highest number of sleep-deprived students, with 73% of 9- and 10-year-olds and 80% of 13- and 14-year-olds identified by their teachers as being negatively affected.

    In literacy(读写能力) tests there were 76% of 9- and 10-year-olds lacking sleep. This was much higher than the international average of 47% of primary pupils needing more sleep and 57% among the secondary age group.

    Other countries with the most sleep-deprived youngsters were New Zealand, Saudi Arabia, Australia, England, Ireland and France. High-performing Finland is also among the most lacking in sleep. Countries with the best records for getting enough sleep include Azerbaijan, Kazakhstan, Portugal, the Czech Republic, Japan and Malta.

    The analysis was part of the huge date-gathering process for global education rankings, the Trends in International Mathematics and Science Study(TIMSS)and Progress in International Reading Literacy Study(PIRLS)

    “I think we underestimate the impact of sleep. Our data show that across countries internationally, on average, children who have more sleep achieve higher in maths, science and reading. That is exactly what our data show,” says Chad Minnich of the TIMSS and PIRLS International Study Center.

    “It's the same link for children who are lacking basic nutrition,” says Mr Minnich, based at the Lynch School of Education, Boston College. “If you are unable to concentrate, to attend mentally, you are unable to achieve at your best level, because your mind and body are in need of something more basic. Sleep is a fundamental need for all children. If teachers report such large proportions of children suffering from lack of sleep, it's having a significant impact. But worse than that, teachers are having to adjust their instruction based on those children who are suffering from a lack of sleep. The children who are suffering from a lack of sleep are driving down instruction.”

    That means that even the children who are getting enough sleep are still suffering from this sleep-related lowering.

    People with an impulsive(冲动的)personality refer to those who tend to do things without considering the possible dangers or problems first. According to a new study by researchers at the University of Georgia, such people may be more likely to have food addiction. The study found that people exhibiting impulsive behavior weren't necessarily overweight, but impulsiveness was related to a direct relationship with food, and therefore, less healthy weight. Food addiction has been compared to addictive drug use. Studies have linked the dopamine (多巴胺)release that occurs after tasting delicious food to the dopamine release that happens when people consume other addictive substances.

    Impulsive behavior involves several personality traits(特点). Two of these traits, known as negative urgency and lack of perseverance, were particularly associated with food addiction and high BMI(身体质量指数)during the study. Negative urgency is characterized by the tendency to behave impulsively when experiencing negative emotions. Some people might drink alcohol or take drugs. For others, it could mean eating to feel better. Lack of perseverance is when a person has a hard time finishing hard or boring tasks. People with a lack of perseverance might have difficulty attempting to change addictive eating behavior, which could also cause obesity(肥胖). “Impulsiveness might be one reason why some people eat in an addictive way despite motivation to lose weight,” said Dr. Ashley Gearhardt, a clinical psychologist. He was involved in developing the Yale Food Addiction Scale in aid of those people. “We are theorizing that if food addiction is really a thing, then our measure, the Yale Food Addiction Scale, should be related to helping control impulsive action,” said Gearhardt.

    Clinical psychologist Dr. James MacKillop, whose lab was conducting the study, believes that therapies used to treat addictive drug behavior could help people who suffer from addictive eating habits.

    “Most of the programs for weight loss at this point focus on the most obvious things, which are clearly diet and exercise,” MacKillop said. “It seems that managing strong desires to eat would naturally fit in with the skills a person would need to eat healthily.”

    Learning Chinese could be one of the most important decisions you ever make. Chinese is becoming the language to learn in the 21^st century. With the world's largest population and a rapidly growing middle class, China stands to become the engine of the world's economy in the coming years. This will make learning Chinese very important for people in many industries, or for those of us who wish to visit China or learn from its culture and history.

    There is an ongoing effort to modernize the writing system and standardize the language. An increasing number of people learning Chinese are learning the Mandarin, so unless you absolutely need to learn another dialect (such as Cantonese), be sure you are studying Mandarin.

For native English speakers Chinese is one of the most difficult and most different languages to learn. The vocabulary is wholly unfamiliar and unlike anything we know. In addition, in the Chinese tone system, words are spoken in rising or falling tones, which help to distinguish between them. Furthermore, there is the Chinese writing system— a collection of thousands of individual ideograms (表意文字), or symbols, which represent a word or an idea. These ideograms have no phonetic value—that is to say, we can't tell how the word is pronounced by how it is written. There is a method to present written Chinese in a phonetic script called pinyin. If you are learning Chinese, you'll be working with this pinyin system, but the beauty of the traditional writing system shouldn't be passed up. All these factors make learning Chinese difficult for us. Yet, for a determined learner, there's always a way to overcome it.

    As data and identity theft becomes more and more common, the market is growing for biometric(生物测量)technologies—like fingerprint scans—to keep others out of private e-spaces. At present, these technologies are still expensive, though.

    Researchers from Georgia Tech say that they have come up with a low-cost device(装置)that gets around this problem: a smart keyboard. This smart keyboard precisely measures the cadence(节奏)with which one types and the pressure fingers apply to each key. The keyboard could offer a strong layer of security by analyzing things like the force of a user's typing and the time between key presses. These patterns are unique to each person. Thus, the keyboard can determine people's identities, and by extension, whether they should be given access to the computer it's connected to—regardless of whether someone gets the password right.

    It also doesn't require a new type of technology that people aren't already familiar with. Everybody uses a keyboard and everybody types differently.

    In a study describing the technology, the researchers had 100 volunteers type the word "touch" four times using the smart keyboard. Data collected from the device could be used to recognize different participants based on how they typed, with very low error rates. The researchers say that the keyboard should be pretty straightforward to commercialize and is mostly made of inexpensive, plastic-like parts. The team hopes to make it to market in the near future.

    Vinegar is great. It makes salad, fries and dumplings taste better, and you can even clean your windows with it. And now, according to scientists, it may even help the planet's population survive climate change.

    Researchers from the RIKEN Center for Sustainable Resource Science (CSRS) in Japan have found that growing plants in vinegar makes them more resistant to droughts. This could mean that in the future, worries about climate change affecting the world's supply of food will be much lower.

    The discovery was made after the researchers studied the Arabidopsis, a plant known for its ability to survive in dry weather. It was found that when the plant was placed in drought-like conditions, it produced a chemical called acetate(醋酸盐)—the main component of vinegar.

    After discovering this, the scientists experimented further by adding acetate to the soil of other plants, and they stopped giving them water completely. After leaving the plants for 14 days, they found that the ones treated with acetate had survived, while the untreated plants had dried up and died. It's hoped that this simple method of survival could soon be used to help farmers in dry countries keep their crops alive.

    Jong Myong Kim, co-author of the study, tells Popular Science magazine that he's already been in touch with people all over the world who are interested in trying this simple and cost-effective method out for themselves from flower growing companies to amateur gardeners. Although at this point keeping thirsty plants alive isn't as easy as just pouring vinegar over them, Kim says he and his team are working on making the process as simple as possible. "Now we are trying to cooperate with some farmers, and also some companies, to make a method to apply this system," he says.

    And for those of us who always forget to ask our neighbors to water our plants when we go away, hopefully this means the end of returning home from a trip to find our favorite flowers have died.