People who multitask all the time may be the worst at doing two things at once, a new research suggests. The findings, based on performances and self-evaluation by about 275 college students, indicate that many people multitask not out of a desire to increase productivity, but because they are easily distracted and can't focus on one activity. And “those people turn out to be the worst at handling different things,” said David Sanbonmatsu, a psychologist at the University of Utah.

    Sanbonmatsu and his colleagues gave the students a set of tests and asked them to report how often they multitasked, how good they thought they were at it, and how sensation-seeking (寻求刺激) or imperative (冲动) they were. They then evaluated the participants' multitasking ability with a tricky mental task that required the students to do simple mathematical calculations while remembering a set of letters.

    Not surprisingly, the scientists said, most people thought they were better than average at multitasking, and those who thought they were better at it were more likely to report using a cellphone while driving or viewing multiple kinds of media at once. But those who frequently deal with many things at the same time were found to perform the worst at the actual multitasking test. They also were more likely to admit to sensation-seeking and impulsive behavior, which connects with how easily people get bored and distracted.

     “People multitask not because it's going to lead to greater productivity, but because they're distractible, and they get sucked into things that are not as important.” Sanbonmatsu said.

    Adam Gazzaley, a researcher at the University of California, San Francisco, who was not a member of the research group, said one limitation of the study was that it couldn't find out whether people who start out less focused tend toward multitasking or whether people's recognizing and understanding abilities change as a result of multitasking.

    The findings do suggest, however, why the sensation-seeker who multitask the most may enjoy risky distracted driving. “People who are multitasking are generally less sensitive to risky situations.” said Paul Atchley, another researcher not in the group. “This may partly explain why people go in for these situations even though they're dangerous.”

    "Iris scan (虹膜扫描), please," the bank's computer voice tells you . You step up and the computer reads your eye, comparing it to the stored file it has of your iris. The images had better match—otherwise you won't be able to get your money.

    Iris scanning and other technologies, such as fingerprint and voice scanning, have appeared in many science fiction movies in the past. Today, these advanced technologies are part of the real world. They are common at work, the bank, the airport, and your local prison. The iris scan, fingerprint scan, and voice scan are all examples of biometrics( 生物测定学) a fast developing area of automatic personal identification technology . Basically, biometrics uses various ways to verify a person's identity, based on the individual's unique characteristics, including fingerprints, voices, irises, body heat patterns, facial images, handprints, signatures and so on.

    Biometrics identification systems have a number of advantages over password systems. The primary advantage is that an individual has to be physically present in order to be identified. Another important advantage is that there are no passwords to remember, forget, lose or steal.

    The voice scan is the simplest and most affordable form of biometrics. It only requires a computer, a microphone and the correct software. The software records a subject's voice and then compares it to a stored voice sample for identification purposes.

    For additional safety, fingerprint and handprint scans can also be employed. Fingerprint scans take the image of a fingerprint and compare it to a stored file of prints. Handprint scans identify the unique features of a hand.

    Iris scans currently give the highest level of accuracy among all the available biometrics systems. Another technology, full facial scans, is currently in use at border crossings and airports. Facial scanning equipment can actually track and identify moving faces within a crowd.

    The potential of biometrics is exciting and encouraging. With continued development, testing, and application, current technologies will become even more effective in the future. Soon, the days of password and car keys will be gone. Just don't leave home without your fingerprints!

    Peter Skyllberg, a Swedish man, was trapped in his car for two months, with temperatures reaching -30^oC, with no food or water, and yet he survived. The best explanation was that his vehicle created an “igloo (snow house) effect” and protected him from the extremely low temperatures and that his body would hibernate(冬眠) during this time.

    Can humans get into a low-energy consumption state like a bear by reserving energy, and reducing body temperature? Chinese scientists are looking for the key to regulating body temperature.

    Scientists have found the hypothalamus (下丘脑), an area in the central lower part of the brain, is responsible for regulating body temperature. Wang Hong, a brain scientist at the Shenzhen Institutes of Advanced Technology of the Chinese Academy of Sciences, led her team to mark the neurons (神经元) responsible for regulating body temperature in mice by means of a cutting-edge genetic biology technique. In the experiments, they injected (注射) drug into mice to make the body temperatures of the mice drop rom 37℃ to 27 in two hours. The team found the change in body temperature caused no harm to the health of the mice. “We don't know if we can develop a drug that can control human body temperature. We still need a lot of study.” Wang said.

    Chinese scientists are not alone in such research. Body-cooling techniques are being used in pioneering hospitals around the world. Dutch doctors are now using low temperatures for patients who have suffered brain injuries in accidents, According to doctors working in Florence, it may even help to save the brains of babies who are born suffering from severe epileptic fits (癫痫病发作).

    Knowing what to do at checkout and properly preparing for it can turn a potentially heated situation into a quick thank you add goodbye. Below we made a list of five things you should remember at hotel checkout.

Don't be late to check

    Hotels may add an extremely high price for being just a half hour late. If you know you won't make the cutoff time, it never hurts to call ahead and try to negotiate away a potential charge.

    Don't forget to double cheek the room and safe

    Make sure you don't leave things behind. If you have an early flight or checkout time, pack up as much as you can the night before so that last-minute rush isn't too annoying. Also, be sure to take out anything in the room safe.

    Don't forget to tip the housekeepers

    It's always polite to leave some money for the people keeping your room clean.

    Don't ignore the detailed bill

    You may be in a rush, but give the detailed hill a careful look to see if the hotel charge is different from the rate you initially booked.

    Don't get angry

    Shooting at the assistant manager standing behind the front desk probably won't help.

    When dealing with an unexpected item on the bill. Think about how difficult it can be to deal with annoyed customers. Keep calm and things may be solved better and sooner.

    Government in Tibet have denied the permanent( 永久的) closure of Mount Qomolangma National Nature Reserve.

    The announcement came after a report went viral online claiming the base camp of the world's highest mountain was "permanently closed due to heavy pollution" and caused a universal misunderstanding.

    Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33, 800 square km, it is home to one of the world's most weak ecosystems(生态系统).

    Kelsang, deputy director of the reserves administration, said ordinary tourists are allowed to visit areas around Rongpo Monastery, almost 5,000 meters above sea level. As for travelers who have a climbing permit, they can go to the base camp at an altitude of 5,200 meters. The mountaineering activities have been permitted by the regional forestry department.

    To conserve the environment surrounding Mount Qomolangma, China carried out three major clean-ups at an altitude of 5, 200 meters and above last spring, collecting eight tonnes of household wastes, human wastes and mountaineering trash. This year, the clean-up will continue, and the remains of mountaineering victims(受害者) above 8,000 meters will be centrally dealt  with for the first  time. Meanwhile, the number of people who stay at the base camp will be kept under 300.

Recently, there are 85 wildlife protectors in the reserve, and 1,000 herders have part-time jobs going around and cleaning up garbage.

These measures aim to strike a balance between various demands such as environmental protection, local poverty relief, mountaineering and education, said Wang Shen, county chief of Dingri at the mountain foot.

It was a fine day. Jeffrey Del Monte was driving With his friend late Friday afternoon along the beach near Ramp 49 in Friso when they heard the screams of children. They surveyed the water trying to locate the screams and, two young girls were spotted apparently struggling while being swept out in a rip current(激流).

Del Monte then swam out into the ocean and helped one of the girls who were caught in the rip current, passing her to his friend for the lengthy swim back to shore. He then went back to search for the second girl and found her in great pain before he swam back to shore, bringing the child to the beach from nearly 100 yards out.

After both girls were safe on the beach, Del Monte and his friend attended to them until Dare County Emergency Medical Services and a Cape Hatteras National Seashore Ranger arrived on the scene. The children's parents also arrived and expressed their thanks to Del Monte and his friend.

"Jeffrey Del Monte's heroic, selfless and quick actions were key to saving these two girls from a very dangerous situation," National Parks of Eastern North Carolina Superintendent David Hallac said in a statement. "His courage and expertise allowed him to perform this successful ocean rescue."

Park officials said the incident was a reminder of how quickly ocean conditions could change, even on what appeared to be a perfect clay.

"A perfect clay on the beach doesn't always mean that it's a perfect day in the ocean, so it is important that all visitors check the beach forecast for danger and rip currents before heading to the beach and always use something that floats when in the water. If individuals do find themselves caught in rip currents, please don't swim against the currents, instead swimming out of the currents and then to shore," David Hallac said.