Runners who encounter visual and auditory distractions (干扰)may be more likely to suffer leg injuries, according to research by the Association of Academic Physiatrists in Las Vegas. Runners often seek distraction from the task at hand. Whether it be music, texting, daydreaming, taking in the sights, or propping a book up on the treadmill(跑步机), more often than not a distraction is welcome. But, researchers from the University of Florida have recently discovered those distractions may lead to injury.

    Daniel Herman, MD, assistant professor at University of Florida, and his team conducted research on the effects of visual and auditory distractions on 14 runners to determine what effect these distractions would have on things such as heart rate, how many times a runner breathes per minute and how much oxygen is consumed by the body.

    The runners were all injury-free at the time of the study and ran 31 miles each week. Dr . Herman's team had each participant run on a treadmill three separate times. The first time was without any distractions. The second time added a visual distraction, during which the runners concentrated on a screen displaying different letters in different colors with the runner having to note when a specific letter-color combination appeared. The third time added an auditory distraction similar to the visual distraction, with the runner having to note when a certain word was spoken by a certain voice.

    When compared to running without distractions, the participants applied force faster to their left and right legs called loading rate, with auditory and visual distractions. They also experienced an increased amount of force from the ground on both legs, called ground reaction force, with auditory distractions. Finally, the runners tended to breathe heavier and have higher heart rates with visual and auditory distractions than without any distractions at all.

    "Running in environments with different distractions may unfavorably affect running performance and increase injury risk," explains Dr. Herman. "Sometimes these things cannot be helped, but you may be able to minimize potentially cumulative(累积的) effects. For example, when running a new route in a chaotic environment such as during a destination of marathon, you may want to skip listening to something which may require more attention - like a new song playlist."

    Dr. Herman's team will continue to investigate the potential relationship between distracted running and leg injuries, and any effect this relationship has on different training techniques that use auditory or visual cues.

    Whenever we see a button on a doorbell or on a remote, we may press it. This is true in most cases. But some buttons are actually fake(假的), like the "close" button on an elevator.

    Many people are in the habit of pressing the "close" button because they don't have the patience to wait for the elevator doors to shut. But according to experts, the buttons are a complete trick—the doors will not close any faster however hard you press.

    It started in the 1990s when the Americans with Disabilities Act was passed, making sure that all elevators stayed open long enough so that people with disabilities could enter. Only firefighters and maintenance workers(维修工) can use the buttons to speed up the door-closing process if they have a code or special keys. But to normal elevator riders, the buttons aren't completely useless.

    According to psychologists, fake buttons can actually make you feel better by offering you a sense of control. Experts have showed that a lot of buttons that don't do anything exist in our lives for this same purpose. For example, pedestrian crosswalk buttons don't live up to their names. Pressing them used to help make the traffic signals change faster, but that was before computer-controlled traffic signals were introduced.

    But psychologists found it interesting that even when people are aware of these little "white lies". They still continue to push fake buttons because as long as the doors eventually close, it is considered to be worth the effort.

    That habit is here to stay, John Kounios, a psychology professor at Drexel University in the US, told The New York Times. "After all, I've got nothing else to do while waiting. So why not try the chance?"

    Do you love Beats headphones, True Religion jeans, and UGG shoes? These are some of the most popular brands(品牌) around. They are also expensive. But some experts say they are not much better than cheaper brands.

    For example, Jim Wilcox works for Consumer Reports. He tested all kinds of headphones. He says that $80 Koss Pro headphones provide basically the same quality and comfort as Beats. So why do people pay twice or even 10 times as much for the hottest brands?

    Experts say because it's fashionable, and expensive brands send a message. Brands say "I belong" or "I can afford it."

    Some people think that expensive brand names are worth the price. They say that some designer clothes are really of top quality and that they last longer than cheaper brands. Some teenagers choose to wear popular brands because these brands make them feel good about themselves.

    Alexandra Allam, 17, likes to buy brand-name products. "I'd rather spend the extra money getting something I know I'll be satisfied with." she says. Her friend Emmy Swan agrees, saying "As long as you can afford it, it seems reasonable to buy what you want." But not all teenagers agree. "Spending hundreds of dollars for designer is stupid and unreasonable," says Daniel Steinbrecher, 16. "It's fake（假的）happiness."

    People who are against wearing expensive brand names say that many designer brands aren't any better. "It's wasteful to buy things just because they are popular." says Edmund Williams, 15. "You'll feel better if you buy things because you like them. If you have extra money to spend, it would be better to give it to people in need."

    A fresh and gentle wind on your face, soft sand under your feet and blue waters as far as the eye can see. Is there any other Olympic sport that is played in such pleasant conditions as beach volleyball?

    "I've gone to a lot of beautiful places, and met a lot of beautiful people. That wouldn't have happened if I had been playing another sport," said Randy Stoklos, America's most famous beach volleyball player.

    The sport began as a four-a-side game on beaches in Southern California in the 1920s.The first recorded two-man game took place there in 1930, and the first tournament was held in Los Angeles 18 years later. The winners were awarded a case of Pepsi. In the 1950s, women started playing and the sport soon spread to Europe and South America. Yet at that time, beach volleyball was more an entertainment show than a sport, with beauty contests included. The Association of Volleyball Professionals was founded in 1983 and beach volleyball developed into a fast, athletic sport. Its world-wide popularity won beach volleyball a place at the 1996 Olympics in Atalanta, where 24 male teams and 16 female teams took part. At present, the US and Brazil are the best in the world at beach volleyball.

    The game came to China in the early 1990s and there have been national tournaments since 1994. It became an official event at the Eighth National Games in 1997.China's You Wenhui and Wang Lu finished ninth in the women's beach volleyball world championships in Brazil.

    Retired jet engines could help clear the smog that smothered big cities.

    To land at Indira Gandhi Airport is to descend from clear skies to brown ones. New Delhi's air is poisonous. According to the World Health Organization, India's capital has the most polluted atmosphere of all the world's big cities. The government is trying to introduce rules that will curb emissions-allowing private cars to be driven only on alternate days, for example, and enforcing better emissions standards for all vehicles.

    But implementing these ideas, even if that can be done successfully, will change things only slowly. A quick fix would help. And Moshe Alamaro, a researcher at the Massachusetts Institute of Technology, thinks he has one. His idea is to take a jet engine, put it next to one of India's dirty coal-fired power plants, point its exhaust nozzle at the sky and then switch it on. His hope is that the jet's exhaust will disrupt a meteorological phenomenon known as "inversion", in which a layer of warm air settles over cooler air, trapping it, and that the rising stream of exhaust will carry off the tiny particles of matter that smog is composed of. Inversion exacerbates air pollution in Delhi and in many other cities, from Los Angeles to Tehran. A particularly intense example caused the Great Smog of London in 1952, when four days of air pollution contributed to 12,000 deaths.

    Dr Alamaro thinks a jet engine could punch through the inversion layer to create a "virtual chimney" which would carry the trapped pollution above it, so that it could be dispersed in the wider atmosphere. He calculates that all the emissions from a gigawatt coal-fired power plant could be lifted away using a single engine with a nozzle speed of 460 metres a second.

    However, he has not calculated whether a jet engine could disrupt the inversion layer and allow the pollution to escape the city-so he is now going to test that hypothesis. Within eight months, Dr Alamaro plans to put one of his updrafters next to a coal-fired power plant and monitor what happens using a fleet of drones. He is in discussions with Tata Group, a conglomerate with an electricity-generating arm, to run it next to one of the firm's power stations.

Many families take their children on vacation. They will usually travel for a few days or weeks during school breaks. But Julie and Tim Smith planned a longer vacation with their two children. The Smith family is on a one-year trip around the world. They plan to visit 30 countries in all. Right now, the four travelers are about halfway through their trip. Ms. Smith says they are trying to see as much of the world as they can.

Mr. Smith says one of the most interesting experiences of the trip has been meeting new people. He says people have been extremely friendly, very welcoming and love their kids. Eleven-year-old Tyler says he has enjoyed learning about the people they have met. He said, "I learned in Africa that people have very different lifestyles than in America. "His sister, 9-year-old Kara, discovered that she liked Thai food. Ms. Smith says that the trip teaches the children a lot.

It took the family a year to prepare for the trip. They had to sell their house and cars. Ms. Smith left her job and her husband is using unpaid leave. They carry small bags filled with lightweight clothing and whatever else they need. Ms. Smith says she enjoys being able to carry everything she needs on her back. She says she does not miss the things she has back home. "What has become more important is making these memories as a family and taking those with us instead."

The Smiths will continue to head east for the next six months.