Researchers at Brigham found about one in five teenagers now have some degree of hearing damage. The researchers did not say why hearing loss has risen, but other experts have strong suspicions. One likely culprit, they say, is MP3 players.

    An MP3 player can be dangerous to hearing when its decibel level is turned up too high. High-decibel sounds can damage nerve endings, called hair cells. If a sound is loud enough, the damage can be permanent. A loud sound can shake the membrane (薄膜) on which the hair cells sit- “like an earthquake”. That shake can break or even uproot hair cells. When that happens, the hair cells are finished. Human ears cannot regrow hair cells. Therefore, when listening to an MP3 player, set a volume limit and avoid exposure to loud sounds.

    On the other hand, the loudness of today's music may not be totally under your control. Music companies have been purposely turning up the volume. It's a trend called the fight for loudness.

    Play a CD from the 1990s. Then play a newly released tune. Don't touch the volume control. You'll probably notice that the new CD sounds louder than the old one. Why? Sound engineers who create CDs are using dynamic range compression (压缩), a technology that makes the quiet parts of a song louder and the loud parts quieter. The overall effect of compression is a louder recording.

    Many musicians and sound engineers aren't pleased. They say that compression is driving down the quality of today, s music, making it sound flat and blaring. Gray Hobish, a sound engineer, explains that music should be a combination of loudness and softness. But music companies want to make music louder so it will stand out. That's important in the competition among recording companies.

    What about listeners? Many teenagers listen to music on the go in noisy places and through headphones, all of which reduce sound quality. So young listeners may not notice the poorer quality of modem recordings. “To their ears,” says Hobish, “the music sounds fine. And they are not aware of the hidden threat of the music they are enjoying.”

    Durian(榴莲) is probably the smelliest fruit in the world, letting out an unusual unpleasant smell which would make anyone bring up. However, nobody was aware of what gave this fruit its unique smell, so a team of researchers from Singapore decided to take a look at its genome (基因组) and find out,

    Durian is well-known throughout Southeast Asia as the king of fruits, mostly because of its awful appearance and smell. However, the origin of this unpleasant smell was unknown, so researchers decided to map the genome of the fruit, and find the gene that controlled it. A group of genes, volatile sulfur compounds (含硫化合物), became very active in the fruit, and they were found responsible for resulting in the unpleasant smell.

    The fruit confuses everyone with a sulfuric smell, like rotten onions and ingredients. The smell lasts long, mostly because the fruit contains more volatile sulfur compounds. Other species usually benefit from two gene copies at most, but durian has four, leading to the striking smell.

    However, this smell might be an advantage for durian in the wild. Although we find it unpleasant, many animals might be attracted by it. If they eat the fruit, then they can easily spread its seeds everywhere, thus contributing to the distribution of the species.

    The mapping of the durian genome also showed some other information on the species. First of all, the fruit has an impressive number of genes, namely 46,000. Also, with the help of these genes, they saw how it evolved, and discovered it was related to the cacao tree. All the other discoveries have been published in the journal Nature Genetics.

    Despite the striking smell, many people actually enjoy eating the fruit. However, not all durian species are edible, and some of them may even cause damage to our health, Even so, the fruit is often imported, significantly contributing to the economy.

    We all know that exercise is good for your health. But some kinds of exercise may be better than others.

    Running, for example, may help to protect against heart disease and other health problems. Running may also help you live longer. Researchers say it is not important how far you run. It also does not matter how fast or even how often you run. As advertisements for the running shoes Nike say, “Just Do It.”

    Recently researchers studied more than 55,000 adults. About one-fourth of the adults reported running regularly. The study found these runners were considerably less likely than non-runners to die of any form of disease, including heart disease. In fact, the runners lived, on average, three years longer than the non-runners.

    This study lasted 15 years. During that time, more than 3,400 of the individuals died. About 1.200 of the deaths were linked to heart disease, hear, attack or stroke.

    One of the researchers is a man named D.C. Lee, a professor of Iowa State University Compared to non-runners, he said, runners showed a much lower risk of dying from some diseases. “Compared to non-runners, runners showed 30 percent lower risk of death by any causes, including heart attack, stroke and cancer. Also, runners compared to non-runners showed 45 percent lower risk of death by cardiovascular diseases（心血管疾病）, including heart attack and stroke.”

    D. C. Lee and the other researchers found that speed, distance and how often one runs made little difference in reducing the risk of death. The runners in the study averaged between 10 and 16 kilometers per hour. Mr Lee said slower runners and those who only ran once or twice a week were helped nearly as much as those who ran faster and further. “And also we looked at the inning over time and we found that persistent runners（over six years）showed the biggest benefits, as well.”

    China's college graduates are leaving first-tier cities（一线城市）for second-tier ones, according to the annual College Graduates' Employment Report issued on Monday.

    The report said that 22.3 percent of college graduates last year chose to work in first-tier cities—Beijing, Shanghai, Guangzhou and Shenzhen—down 1.3 percentage points from 2016 and 5.9 percentage points from 2013. In 2017, 21.7 percent of college graduates chose to leave first-tier cities after working there for three years, up 2.5 percentage points from 2016 and 8 percentage points from 2015.

    The report also found that leading second-tier cities are attracting more recent graduates. Around 35.6 percent of college graduates who chose to work in the top 10 second-tier cities such as Hangzhou, Chengdu and Wuhan, were from other regions in 2017, up 3.6 percentage points from the previous year.

    The report was based on a survey of 306,000 graduates from 30 provinces and regions. It was released by MyCOS, an education consulting and research institute in Beijing.

    Wang Boqing, founder of MyCOS, said large populations, traffic jam, smog, increasing property prices and great difficulty in obtaining permanent residence（居住）, or hukou in Chinese, have brought high pressure to life in first-tier cities for college graduates, which gives second-tier cities an opportunity to attract talented workers.

    Second-tier cities have rolled out a series of policies to attract university graduates, which include favorable treatment to obtain hukou, as well as housing and government subsidies（津贴）, he said. Wuhan, Hubei Province, has planned to build affordable housing for university graduates, and allow graduates to buy or rent apartments at a discount of at least 20 percent of the market price.

    Chu Zhaohui, a senior researcher at the National Institute of Education Sciences, however, said that the governments of such cities should notice that welfare（福利）, housing and money can attract people in a short time. “Professionals aim mainly at prospects（前景）for career development rather than just benefits,” Chu said, adding that those cities should maintain their advantages, such as low cost of living and nicer environments, to keep their appeal. The cities should provide more opportunities for employment that are similar to those in first-tier cities, he said.

Hot Spots for Retirees to Start Their Encore Career

    Encore Career: Vocational School Instructor

    Retire in: Los Angeles, CA

    Ever since IBM CEO Ginni Rometty coined the term "new collar" to describe well-paid jobs that require specific skills but not necessarily a degree, vocational schools have made a serious comeback. Apparently instructors are in short supply in sunny L.A., where there are 13 jobs at vocational schools for every applicant on the market. This is a great opportunity for skilled retirees since, unlike teaching at a public school that requires a state certificate, the only requirement here is that you be a seasoned expert in your field.

    Encore Career: Business Consultant

    Retire in: Miami, FL

    Consulting is a great option for a retired business professional looking to make their own hours, be their own boss, and earn as much or as little as needed to maintain their standard of living. For every consultant in Miami right now there are 13 businesses hoping to hire them. There's even greater demand here than in Washington D.C., which is typically considered the consulting capital of the world.

    Encore Career: Tourist Wrangler

    Retire in: Austin, TX

    As the economy continues to boom and more Americans have extra income to spend, the tourism industry has taken off. This is particularly true in Austin, TX, where there were astonishing 36 tourism jobs for every applicant in July. Between four-star hotels, the noisy rock n' roll scene, and a new food culture, Austin is the place to be if you want to work in service industry.

    Encore Career: Supporter of the Arts

    Retire in: Charleston, SC

    If you're a Baby Boomer with a degree in the arts, now could be the perfect time to revisit your passion for creativity, especially if you also want to live in the center of southern charm. Between the 14 art galleries on King Street in Old Town, an abundance of acting companies and theaters, and music festivals, it's not surprising there were 25 jobs for every arty applicant iii Charleston.

What makes preschoolers eat their vegetables? Raise their hand? Wait their turn? "Because I say so" is a comment that parents often repeat. But when it comes to getting kids to behave, a recent study by Duke University researchers suggests that the voice of adult authority isn't the only thing that matters. Around age three, fitting in with the group starts to count big too.

To understand what cause preschoolers to fall    in    line, the researchers conducted a test in a lab, where they invited 3.5-year-olds to help set up for a pretend tea party. Each of the 104 children was given a blue sticker (贴纸) to wear at the start of the study, and told that the people with that color sticker were part of the same team. Next the researchers watched as the children decided among different kinds of teas, snacks, cups and plates for the tea party, first on their own and then after listening to the choices of other team members.

Sometimes the other team members considered their choice as a matter of personal preference ("For my tea party today, I feel like using this snack.") Other times they presented it as a need shared by the whole group. ("For our tea parties today, we always use this kind of snack.")

After listening to the choices of others, most of the time the children stuck with their first choice. In other words, children who had said they felt like using, say, the cookie finally picked the cookie no matter what the other person said they were using. But 23% of the time the children changed their choice to accept someone else's. And when they did, they were more likely to go along with the other person when a choice was presented as a group need rather than just a personal preference. The finding held up even when the other person was another child, not an adult.