Modern man has cleared the forests for farmland and for wood, and has also carelessly burned them. More than that, though, he has also interfered(干预) with the invisible bonds between the living things in the forests. There are many examples of this kind of destruction. The harmfulness of man's interference can be seen in what happened many years ago in the forest of the Kaibab plateau （凯亚巴布高原） of northern Arizona. Man tried to improve on the natural web of forest life and destroyed it instead.

    The Kaibab had a storybook forest of large-sized pine, Douglas fir, white fir, blue and Engelmann spruce. In 1882 a visitor noted, "We, who have wandered through its forests and parks, have come to regard it as the most enchanting（迷人的）region it has ever been our privilege to visit. "This was also the living place of the Rocky Mountain mule deer. Indians hunted there every autumn to gather meat and skins. The forest also had mountain lions, timber wolves and bobcats that kept the deer from multiplying too rapidly.

    Then, in 1906, President Theodore Roosevelt made the Kaibab a national game preserve. Deer hunting was forbidden. Government hunters started killing off the deer's enemies. In 25 years' time, 6,250 mountain lions, wolves and bobcats were killed. Before the program, there were about 4,000 deer in the Kaibab, by 1924, there were about 100,000.

    The deer ate every leaf and twig they could reach. But there was not nearly enough food. Hunting of deer was permitted again. This caused a slight decrease in the deer herd，but a far greater loss resulted from starvation and disease. Some 60 percent of the deer herd died in two winters. By 1930 the herd had dropped to 20,000 animals. By 1942 it was down to 8,000.

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    Because of the financial crisis in the US and UK, college students are beginning to struggle to find ways to pay their tuition fees and accommodations.

    Recently, two major US student loan (贷款) lenders, Citibank and JPMorgan Chase, announced they were leaving the student loan industry altogether. Because banks currently have a lack of credit, they are reluctant to offer students low-interest loans that need a several-year wait for any return of interest.

    In the US, many undergraduates fill up their financial needs with a private loan, although the majority can get government-funded loans. In the 2015-2016 academic year, $ 17 billion in private student loans was used to finance higher education. The lack of private funding has yet to be covered and will hit many US students hard.

    Across the Atlantic, UK students have been less troubled by the crisis. Most undergraduates in the UK cover their university expenses with government-funded loans and grants. Their biggest concern is a sudden increase in student rent.

    Most young professionals now rent houses, since 80 percent of UK mortgage schemes (按揭计划) have disappeared—a direct result of the credit crisis. This has boosted the house rent market.

    In large cities, UK students are paying almost 6.5 percent more in rent than the previous year. Figures from the UK organization Accommodation for Student show students in big cities such as London paying an average weekly rent of $ 203.

    Yet, despite students' suffering, the number of this year's university applications is expected to grow. During economic slumps, people regard further education as a way to survive tough job market.

    When Dee Dee Bridgewater learned that she would become a 2017 NEA Jazz Master, a series of thoughts and feelings flooded her mind. “It was so far out of my orbit and just my whole sphere of thinking,” she said in a conversation at NPR this spring, hours before she formally received her award.

    She's 66-far from retirement age in jazz, and on the extreme forward edge of the NEA Jazz Masters people. So she was aware of her relative youth in the field She also recognized that there haven't been many women in the ranks of NEA Jazz Masters: fewer than 20, out of 145. That idea led her to reflect on her predecessors (前任): legendary singers like Betty Carter* who was seated back in 1992, and Abbey Lincoln, who received the nod in 2003.

    Bridgewater sought inspiration and advice from both Carter and Lincoln, as she recalls in this period of Jazz Night, which features music recorded during the season opener for Jazz at Lincoln Center. On a program called “Songs of Freedom”, organized by drummer Ulysses Owens, Jr., Bridgewater sang material associated with Lincoln as well as Nina Simone: an extremely angry song of the civil rights movement, like “Mississippi Goddam”.

    A separate concert, “Songs We Love”, found Bridgewater singing less politically charged (but still exciting) fare like “St. James Infirmary”, which appears on her most recent album. In words as well as music, this period reveals how seriously Bridgewater takes that responsibility, seeing as how it connects to her own experience in the jazz lineage. But maybe “seriously” isn't the right word when it comes to Dee Dee, whose effervescence (欢腾) shines through even in a reflective mood. Join her here for a while; she's excellent company, no more or less so now that mastery is officially a part of her resume.

    Mya Le Thai is a scientist studying at the University of California, Irvine. She recently discovered a process that may result in batteries that last forever. Thai said she had been discouraged that the batteries for her wireless devices degrade. Over time, they fail to charge fully.

    Thai did not like to have keep her wireless laptop connected to an electrical outlet. She decided to do something about that problem.

    At first, she and her team thought about inventing a new battery. But as they experimented, Thai discovered something that might permit lithium-ion(锂离子) batteries to last forever. Lithium-ion batteries power most wireless devices. Over time, the batteries lose the ability to hold a charge. Most of these batteries have a life span of about 7,000 charging cycles before they die.

    One of the reasons lithium-ion batteries degrade is their use of nanowires(纳米线) to carry electricity. Nanowires are extremely thin. A human hair is thousands of times thicker, for example. Nanowires are extremely efficient carriers of electricity, which makes them useful in batteries. But Thai said their thinness also makes them weak. "Nanowires break over time," she said. "That's why they lose capacity."

    But, Thai had a theory: The nanowires might last longer if covered with a material. She and the team tested her theory. The team tried many coverings for the wires. PMMA was one of them. The nanowires were coated with PMMA and cycled through charges 200,000 times. The PMMA coated nanowires showed no evidence of damage. The results suggest that batteries could last forever, without losing charging ability.

    Thai hopes to continue her research to understand why this material works so well and to see if any other material could create better results.

"It's kind of cool," she said. "I'm really glad people are showing interest in my work and not just in the work itself, but also in technology and energy."

    A new study, conducted by British company Mindlab International, has found that listening to music at work increases accuracy (精确) and speed, The Telegraph reported.

    Perhaps, some parents disagree with this idea, saying, "Switch off the music and concentrate!" Well, if that's the case with your parents, you might now be able to convince them that you have science on your side.

    The company gave 26 participants （参与者）a series of different tasks for five days in a row, including spell checking, mathematical word problems, data entry, and abstract reasoning. The participants completed these tasks while listening to music or no music at all.

    The results showed that while music was playing, 88% of participants produced their most accurate test results and 81% completed their fastest work. David Lewis, chairman of Mindlab International, told The Telegraph, "Music is a very powerful management tool if you want to increase not only the efficiency of your workforce but also their emotional state, they are going to become more positive about the work."

    However, you may have a list of your favorite songs, but not all kinds of music match all homework. For maths or other subjects involving numbers or attention to detail, you should listen to classical music, the study found. In the study, pop music enabled participants to complete their tasks 58% faster than when listening to no music at all. If you are reviewing your English writing, pop music is the best choice, as it is the best kind for spell checking. It cut mistakes by 14%, compared to listening to no music. After finishing your homework, do you often take time to check your answers? Maybe, some dance music is suitable for you.

    Before uploading a photo of ourselves to social media, chances are that we'll use an app to smooth our skin, make our eyes look bigger, and lips fuller. With a couple of taps on our mobile phone, we can get a quick fix and present the "best" version of ourselves to the world. However, the problem is, when we simply edit our imperfections away, we're also changing the way we look at ourselves.

    Last month, researchers published the article Selfies – Living in the Era of Filtered(过滤的) Photographs. The article analyzed photo editing apps' bad influences on people's self-respect and their possibility to cause appearance anxieties. The researchers also warned that such apps make it difficult to tell the difference between reality and fantasy. "These apps allow one to change his or her appearance in minutes and follow an unrealistic standard of beauty," the article reads.

    In the past, people may have compared their looks to those of famous persons. But for today's young people, beauty standards are most likely set by what they see on social media. "From birth, they are born into an age of social platforms where their feelings of self-worth can be based purely on the number of likes and followers that they have, which is linked to how good they look." British cosmetic doctor Tijion Esho told The Independent. This is why many young people suffer an identity trouble when it comes to appearance.

    "Now you've got this daily comparison of your real self to this fake self that you present on social media." Renee Engeln, a professor of psychology, told the HuffPost website. Engeln further pointed out that when people spend too much time making such comparisons, they may become "beauty sick" and find it difficult to accept what they actually look like. "Because between you and the world is a mirror, it's a mirror that travels with you everywhere. You can't seem to put it down." she told The Washington Post. So when we look in a real mirror, we shouldn't think to ourselves, "Do I look as good as myself in the filtered photos?" Instead, we should think, "I feel good; I have my health."