Elephants might be the most well-known and well-loved animal in African wildlife. But conservation (保护) of the African elephant faces special difficulties. While the elephant population is half of what it was 40 years ago, some areas of Africa have more elephants than populated areas can support. That's why AWF scientists are studying elephant behavior, protecting habitats and finding ways for humans to live peacefully with elephants in Africa.

    Years ago, over hunting and the ivory trade were the biggest threats to elephants survival. Luckily, ivory bans (禁令), hunting rules and protected areas protect elephants from these dangers today.

    The 21st century brings a different challenge to elephant conservation —land-use. Elephants walk across borders and outside parks and other protected areas. So they often destroy crops, causing conflicts (冲突) between local farmers and these big animals.

    Successful conservation strategies (策略) must allow elephants to walk freely in their natural habitats while reducing conflicts between elephants and local people.

    AWF researchers are searching for a way to give both elephants and people the space they need. The AWF is collecting information on elephant habitats and behavior. The information they gather will help to develop the widest possible space for elephants.

    The AWF is helping elephants by protecting their habitats. And they also work with local farmers to improve their life in order to encourage them to protect rather than destroy elephants.

    Hilversum is a medium-sized city between the major cities of Amsterdam and Utrecht in the Gooi area of North Holland, the Netherlands. Unlike most of the Netherlands, Hilversum is actually in a hilly area with the soil mostly consisting of sand. Once called the Garden of Amsterdam, it still attracts travelers to come over to cycle and walk through the surrounding forests. They visit it for a relaxing day off from the urban madness. For Dutch people, Hilversum is all about textile (纺织) and media industries, and modern architecture.

    In history, Hilversum was largely an agricultural area. Daily life was marked by farming, sheep raising and wool production. A railway link to Amsterdam in 1874 attracted rich traders from Amsterdam to Hilversum. They build themselves large villas (别墅) in the wooded surroundings of the town. One of the families moving in was the Brenninkmeijers, currently the wealthiest family of the Netherlands. They moved in after big success in the textile industry and aided a substantial textile industry in Hilversum. But the textile boom lasted only several decades. The last factory closed in the 1960s.

    The change to a media economy started in 1920, when the Nederlandse Seintoestedllen Fabriek (NSF) established a radio factory in Hiversum. Most radio stations called in the large villas in the leafy areas of the town. Television gave another push to the local economy. Hilversum became the media capital of the Netherlands, and Dutch televison stars moved into the leafy neighborhoods surrounding the town.

    In the early 1900s, modern architcts W.M. Dudok and J. Duiker placed hundreds of remarkable buildings in Hilversum. These modern architectural masterpieces (杰作) are so many that Hilversum almost feels like an open air museum. Dudok alone shaped most 20th century Hilversum and approximately 75 buildings in 1928-1931. It has wide international fame and is included in many architecture textbooks. The building has a remarkable shape and looks like a combination of “blocks”. Actually, one may start his journey of modern architecture by walking or biking the W.M. Dudok Architectural Route in Hilversum.

    Even if trees cannot walk, they are still on the move.

    In parts of the Arctic, entire forests are moving northward. Across the Arctic, temperatures are rising faster than anywhere else in the world. As that happens, the tree line that marks where forests stop and the treeless tundra (冻原) starts has been shifting northward. Trees growing along the tree line must protect themselves from the cold wind. To dothis, plants tend to grow horizontal (水平的) branches low to the ground. The energy it takes for trees to grow this way means they don't have enough energy to make seeds.

    But as Earth's climate has been warming, trees no longer have to just grow horizontally. Many can instead grow up toward the sky. This takes less energy. And with all that leftover energy, these trees have started producing more seeds. This happens especially in places where white spruce (白云杉) grows.

    White spruce, which is a North American tree, is quite able to produce a lot of seeds, which can move long distances in the wind. When wind­blown seeds end up on the tundra beyond the tree line, they eventually can sprout(发芽) new trees. This explains how a forest can move. Of course, the process would work only if the tundra were warm enough. But in recent years, the whole planet has been warming.

    New trees will provide shelters for some snow. Keeping the sun's rays from making the white surface disappear. Instead, the trees absorb the sun's heat. This warms the surrounding air. The extra warmth encourages even more trees to produce seeds. That further boosts a forest's ability to expand. In addition, more trees will trap more snow, preventing much of it from being blown away. Snow can trap heat in the soil below, which encourages trees to grow. The recent rise of temperatures has helped more trees grow past the tree line. People worry about impacts on the animals that depend on frozen conditions for food and shelter.

    Imagine yourself on the other side of the college admissions desk. It's not so glorious, apparently. At the very least, you need to be good-natured. Joseph Connolly, a guidance counselor at New Oxford High School in the United States, wanted to know the things that annoy admissions officers the most. He sent out a request to members of the National Association for College Admissions Counselors and received hundreds of responses. Apparently, college admissions officers were waiting for an opportunity to unload their frustrations. The responses fall into several areas:

    Communication

    Silly or stupid email addresses; sending emails that use texting shorthand, such as "im w8ing 4 some1 2 call me."

    Leaving a message with just a first name and no telephone number. For example, "Hi, this is Suzie. Please call me back."

    Acting distracted during a one-on-one interview; nervous habits like foot-tapping or "um", "like" and "you know", which make a bad situation worse.

    Not responding to emails from the admissions office.

    Over-involved parents

    The very common comment from parents, "We are in the process of completing applications."

    Parents attending interviews, and worse yet, speaking for their children.

    Essays

    Not identifying which question they are responding to.

    Writing about something they were great at in the seventh grade but haven't pursued since then.

    People love cellphones, which is why nine in ten Americans own one. But does heavy use of cellphones pose a risk of cancer? This question has caused controversy for many years. A new study in rats now augments those concerns. Its data linked long-term, intense exposure to radiation from cellphones with an increased risk of cancer in the heart or brain. The results have yet to be confirmed, the authors note.

    Indeed, although the rat study found a link between cellphone radiation and cancer, it offers no clues to why such a link might exist, notes Jonathan Samet. He teaches preventative medicine and directs the Institute for Global Health at the University of Southern California in Los Angeles. Still, he calls the new study's findings “significant”.They could lead to studies researching how cellphone radiation might cause cancer, he says.

    Phone signals are relayed between cell towers and cellphones via radio waves. This radio frequency—or RF—radiation is a type known as non-ionizing (非电离的).Unlike X-rays, non-ionizing radiation does not deposit enough energy into cells to release electrons from atoms or molecules, producing ions. So it tends to be far less harmful than ionizing radiation, such as X-rays. But that does not mean radio waves might not cause harm.

    In very large doses (量) this radiation will heat the body and cause tissue damage. But it's not yet known what much lower RF levels might do, such as those from cellphone use. Five years ago, the World Health Organization's International Agency for Research on Cancer, or IARC, concluded that cellphone use “is possibly carcinogenic (致癌的)”.

    Its conclusion was based on what little research data was available at that time. But notice that IARC was not certain. It said only that phone use might “possibly” cause cancer. So scientists at the National Toxicology Program, or NTP, investigated further.

    It's school time again! You're probably feeling excited and maybe a little sad for the vacation is over. Some kids feel nervous on the first day of school because of all the new things: new teachers, new friends, and maybe even a new school. Luckily, these "new" worries only stick around for a little while. Let's find out more about going back to school.

    Most teachers kick off the school year by introducing themselves and talking about what you'll be doing that year. Some teachers give students a chance to tell something about themselves to the rest of the class.

    When teachers do the talking on the first day, they often go over classroom rules so you'll know what's allowed and what's not. Pay close attention so you'll know if you need to raise your hand to ask a question and what the rules are about visiting the restroom.

    You might already know a lot of people in your class on the first day. But it's a great day to make new friends, so try to say "hello" to the kids you know and new ones that you don't. Make the first move and you'll be glad about what you did and so will your new friends!

    Most teachers let you pick your own seat on the first day, but by the second or third morning, they'll have mapped out a seating plan. It's a good idea to write down where your seat is in your notebook so you don't forget.

    Here are a few final tips for a fantastic(奇异的) first day: Get enough sleep. Have a healthy breakfast. Try your best. Develop good work habits, like writing down your assignments(作业) and handing in your homework on time. Take your time with schoolwork. If you don't understand something, ask the teacher.