After years of debate, gray wolves were reintroduced (重新引进) to Yellowstone National Park. Fourteen wolves were caught in Canada and moved to the park. By 2016, the Yellowstone wolf population had grown to more than 170.

    Gray wolves once were seen here and there in the Yellowstone area and other pans of United States, but they were gradually displaced by human development. By the 1920s, wolves had disappeared from the Yellowstone area. They went farther north into the deep forests of Canada, where there were fewer humans around. The disappearance of the wolves had many unexpected results. Deer and elk populations—major food sources(来源) for the wolf—grew rapidly. These animals ate large amounts of plants, which reduced plant diversity(多样性) in the park. With the disappearance of gray wolves, coyote (草原狼) populations also grew quickly. The coyotes killed a great number of red foxes in the park, and completely drove away the park's beavers (河狸).

    As early as 1966, biologists asked the government to consider reintroducing wolves to Yellowstone Park. They hoped that wolves would be able to control the elk and coyote problems. Many framers were against the plan because they feared that wolves would kill their farm animals or pets.

    The government spent nearly 30 years thinking lip a plan to reintroduce the wolves. The U.S. Fish and Wildlife Service carefully monitors and manages the wolf packs in Yellowstone. Today, the debate continues over how well the gray wolf is fitting in at Yellowstone. Elk, deer, and coyote populations are down, while beavers and red foxes have made a comeback. The Yellowstone wolf project has been a valuable experiment to help biologists decide whether to reintroduce wolves to other parts of the country as well.

    “Educational researchers, political scientists and economists are increasingly interested in the characteristics and skills that parents, teachers and schools should foster in children to increase chances of success later in life,” said lead author Marion Spengler, PhD of the University of Tubingen.” Our research found that specific behaviors in high school have long-lasting effects for one's later life.”

    Spengler and her co-authors analyzed data collected by the American Institutes for Research from 346, 660 U. S. high school students in 1960, along with follow-up data from 81,912 of those students 11 years later and 1,952 of them 50 years later. The initial high school phase measured a variety of student behaviors and attitudes as well as personality characteristics, cognitive abilities, parental socioeconomic status and demographic(人口统计的)factors. The follow-up surveys measured overall educational attainment, income and occupational prestige(声望).

    Being a responsible student, showing an interest in school and having fewer problems with reading and writing were all significantly associated with greater educational attainment and finding a more prestigious job both 11 years and 50 years after high school. These factors were also all associated with higher income at the 50-year mark. Most effects remained even when researchers controlled parental socioeconomic status, cognitive aibility and other broad personality characteristics such as conscientiousness.

    While the findings weren't necessarily surprising, Spengler noted how reliably specific behaviors people showed in school were able to predict later success.

    Further analysis of the data suggested that much of the effect could be explained by overall educational achievements, according to Spengler.

    “Student characteristics and behaviors were rewarded in high school and led to higher educational attainment, which in turn was related to greater occupational prestige and income later in life,” she said. “This study highlights the possibility that certain behaviors at crucial periods could have long-term consequences for a person's life.”

    There's a new frontier in 3D printing that's beginning to come into focus: food. Recent development has made possible machines that print, cook, and serve foods on a mass scale. And the industry isn't stopping there.

    Food production

With a 3D printer, a cook can print complicated chocolate sculptures and beautiful pieces for decoration on a wedding cake. Not everybody can do that—it takes years of experience, but a printer makes it easy. A restaurant in Spain uses a Foodini to" re-create forms and pieces" of food that are" exactly the same,” freeing cooks to complete other tasks. In another restaurant, all of the dishes and desserts it serves are 3D-printed, rather than farm to table.

    Sustainability(可持续性)

    The global population is expected to grow to 9.6 billion by 2050, and some analysts estimate that food production will need to be raised by 50 percent to maintain current levels. Sustainability is becoming a necessity. 3D food printing could probably contribute to the solution. Some experts believe printers could use hydrocolloids( 水解胶体)from plentiful renewables like algae(藻类) and grass to replace the familiar ingredients(烹饪原 料). 3D printing can reduce fuel use and emissions. Grocery stores of the future might stock "food" that lasts years on end, freeing up shelf space and reducing transportation and storage requirements.

    Nutrition

    Future 3D food printers could make processed food healthier. Hod Lipson, a professor at Columbia University, said, "Food printing could allow consumers to print food with customized nutritional content, like vitamins. So instead of eating a piece of yesterday's bread from the supermarket, you'd eat something baked just for you on demand."

    Challenges

    Despite recent advancements in 3D food printing，the industry has many challenges to overcome. Currently, most ingredients must be changed to a paste( 糊状物)before a printer can use them, and the printing process is quite time-consuming, because ingredients interact with each other in very complex ways. On top of that, most of the 3D food printers now are restricted to dry ingredients, because meat and milk products may easily go bad. Some experts are doubtful about food printers, believing they are better suited for fast food restaurants than homes and high-end restaurants.

    Next autumn when you see wild geese heading south for the winter flying in a V formation you might think about what scientists have discovered as to why they fly that way.

    As each bird flaps(拍打) its wings, it creates an uplift(升力) for the bird immediately following. By flying in V formation the whole group adds at least 71% greater flying range(航程) than if each bird flies on its own.

    People who share a common direction and sense of community can get where they are going more quickly and easily because they are traveling on the push of one another. When a wild goose falls out of the formation, it suddenly feels the drag and resistance(阻力) of trying to go alone and quickly tries to get back into the formation to take advantage of the lifting power of the bird in front. When the head goose gets tired, it flies back into the formation and another goose flies to the front. It is wise to take turns doing difficult jobs whether it be people or wild geese flying south.

    Wild geese honk(发出雁叫声) from behind to inspire those up front to keep up their speed. When a wild goose gets sick or wounded by gunshots, and falls out of the formation, two other geese will fall out with that goose and follow it down to lend help and protection. They will stay with the fallen goose until it is able to fly or until it dies, and only then will they go on with their own or with another formation to catch up with their group.

    Becca was 6 when she was told she had cancer on Sept. 8, 2014. She clearly remembers the bad days of her 26 months of non­stop treatment. Luckily, Becca celebrated her final treatment on Nov. 13, 2016, and she has been cancer­free ever since. But she was thinking about what her life was like while experiencing treatment.

    I was never able to do much, and that's what the kids lying in their hospital beds right now experience, asking their mom and dad, "When are we leaving? When can I play with my friends？" So I decided I have to help them.

    In February, 2017 Becca came up with the idea for Knots and Arrows, a company that makes bracelets (手镯) out of swimsuit materials (泳衣布料). Part of the money made from each bracelet goes to the organizations that help people with cancer.

    Becca created the company with her father, Gerhard Salmins. Gerhard Salmins once had cancer and already recovered from it. "I would be in the hospital sitting there crying and then my dad would come in and he would play games with me，" she said. "It made me forget about what I was going through." Becca said the name of the organization shows the motto (座右铭) she stuck to through her personal cancer journey.

    Her organization has already given thousands of dollars to research organizations and families in need. Becca said she hopes her bracelets will make people remember that great things can result from small changes. "No matter what age you are, what you look like, how you act, you can make a difference!" she said.

Let's Go Fly a Kite...

—at Piedmont Middle School's celebration of kites!

    Come and learn how to build all sorts of kites, from the simplest diamond-shaped kites to the most complex(复杂的) box kites. Stay as long as you like and build as many kites as you want. Once you have finished a kite, get advice on flying techniques from kite expert Lorena Hallsberg. The celebration will be at Piedmont Middle School, 151 Piedmont School Drive.

    The Piedmont Middle School Parent Teacher Organization (PTO) has organized a refreshment(茶点) tent. All profits(收益) will benefit future PTO activities. Take a break from kite flying and drink some lemonade! While you are doing so, why not join the PTO? Membership is free; you just donate(捐赠) your time. Show your support for Piedmont Middle School by joining the PTO this Saturday!

    When: Saturday, April 11, from 9:00 am to 5:00 pm

    Where: Piedmont Middle School

    Why: For fun!

    Cost: Free, thanks to a generous gift from Bizarco Kite Company!

    Schedule

    9:00 am: Kite-building booths open. All materials are supplied for kites.

    10:00 am: Kite-building shows by Lorena Hallsberg in the courtyard. Come by and learn how to build box kites and kites that look and fly like butterflies.

    11:00 am: Kite-flying shows on the school track. Learn all the most important skills.

    12:00 pm: Kite-flying competitions on the school track.

    1:00 pm: Presentation by Dr. Brian Lehrman in the show tent: "The History of Kites".

    2:00 pm: Best Kite competitions and judging in the show tent. Come see the most artistic kites and the most interesting theme kites.

    3:00 pm: Presentation by Dr. Lehrman in the show tent: "Kites and Science".

    3:30 pm: Awards(颁奖) ceremony conducted(主持) by Headmaster Seward on the football field. The results of the day's judging will be announced, with awards such as Best of Show, Most Artistic, Highest Flyer, and others. Winners will receive gifts from the Bizarco Kite Company!

    4:00-5:00 pm: Let's all go fly a kite! Everyone flies kites at the same time, creating a wonderful sight for all to enjoy.

    Come to the kite celebration, enjoy yourself and learn more.