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    Would it surprise you to learn that, like animals, trees can communicate with each other and pass on their wealth to the next generation--their young trees?

    Suzanne Simard, forest ecologist at the University of British Columbia, explains how trees are much more complex than most of us ever imagined. Simard and her colleagues have made the major discovery that trees and plants really do communicate and interact with each other.

    Trees live on through their group work and support, passing around the resources such as nitrogen and carbon “depending on who needs it by miles of underground fungi（真菌） networks. This makes sure that all trees in the forest ecological system give and receive just the right amount to keep them all healthy. This system works in a very similar way to the networks of neurons（神经元） in our brains, and when one tree is cut down, it affects all.

Simard talks about "Mother Trees". These are the largest, oldest trees that rise above the forest, a concept explained in the movie Avatar. These “Mother Trees" are connected to all the other trees in the forest by this network of fungi, and may manage the resources of the whole trees and plants in the forest. She explains how these trees pass on the wealth to the next generation, transporting important resources to young trees so they may continue to grow. When humans cut down "Mother Trees" without paying attention to these highly complex "tree societies” or the networks on which they feed, we are losing the chances to save the whole forest.

    "We didn't take any notice of it,” Simard says sadly. “Mother Trees move nutrition into the young trees before dying, but we never give them a chance.” If we could send this message to the forestry industry, we could make a huge difference towards our environmental protection efforts for the future.

      CHICAGO- Have you ever worked on your laptop computer with it sitting on your lap, heating up your legs? If so, you might want to rethink that habit from now on. Doing it a lot can lead to “toasted skin syndrome (症状)”, an unusual-looking spotted skin condition caused by long-term heat exposure (暴露), according to medical reports.

       In one recent case, a 12-year-old boy from California developed a skin discoloration on his left lap after playing computer games a few hours every day for several months. “He recognized that the laptop got hot on the left side; however, he did not change its position,” Swiss researches reported in an article published Monday in the journal Pediatrics.

      Another similar case is a Virginia law student who needed treatment for the spotted darkening on her leg. Dr. Kimberley Salkey, who treated the young woman, learned the student spent about six hours a day working with her computer placed on her lap. As Dr. Salkey later learnt, the temperature under the laptop could reach 51 degrees. That case, from 2007, is one of 10 laptop-related cases reported in medical journals in the past six years.

The condition can also be caused by overuse of heating pads (垫子) and other heat sources that usually aren't hot enough to cause burns. It's generally harmless but can also cause such permanent (永久的) skin darkening. In very rare cases, it can cause damage leading to skin cancers, said the Swiss researchers, Drs. Andreas Arnold and Peter Itin from University Hospital Basel. They do not mention any skin cancer cases linked to laptop use, but suggest, to be safe, placing a carrying case under the laptop if you have to hold it on your lap.

      Dr. Kimberley Salkey said that under the microscope, the affected skin is similar to skin damaged by long-term sun exposure.

      Major producers including Apple and Dell warn against placing laptops on laps or exposed skin for long periods of time because of the risks for burns. In the past, “toasted skin syndrome” has happened to workers whose jobs require being close to a heat source, including bakers and glass blowers, and in people who gathered near hot stoves to stay warm.

Dr. Anthony J. Mancini, chief at Children's Memorial Hospital in Chicago, said that it's unlikely that computer use would lead to cancer since it's so easy to avoid close skin contact (接触) with laptops.

    If you put your history notes under your pillow and sleep on them the night before an exam, will you do any better in the exam? Most of us have hoped this might help. However, knowledge can't go through the pillow into your brain. But that doesn't mean you can't learn while you are asleep.

    Scientists aren't exactly sure how it works, but they have discovered that the brain can learn things during sleeping hours.

    In one experiment, researchers gave German speakers some Dutch words to learn. Then, they divide them into three groups. The researchers played the Dutch words for people in Group 1 while they were asleep, without telling these German speakers what they were doing. The sound was low. So it didn't wake them up, and only the newly introduced words were used.

    Another group listened to the same words while they were awake. The researchers found the people in Group 1 were better able to identify and translate the words later. This was true only for the words that were played while they slept. The third group listened to words when they walked. The walkers didn't have the same success remembering the words as the sleeping group.

    The researchers later found that people had more slow wave(慢波的) brain activity all over the night. They said that more slow waves made people have a better memory for the new words.

    Fresh green grass, Hundreds of colorful wild flowers. Water running into little pools. Birds making their homes in boxes. The 9, 500-square-metre Augustenborg Botanical Garden may look just like any other well-organized park but there's a difference. It lies on the roofs (屋顶) of industrial and office buildings in the city of Malmo in Sweden.

    Green roofs are not a new invention. And now they are getting popular again. The common roofs of a modern city have endless black surfaces with no life or water. Perhaps that's why a garden on a roof becomes such a perfect choice for more and more people.

    Green roofs are not just pretty. They also help to moderate the city temperature. The high temperatures on common roofs in the summer can make top floor flats uncomfortably hot. What is more, they play a part in making the cities hotter than the countryside around them, causing the "urban heat-island effect". On a green roof, however, with its plants and water, temperatures change only a little, as they do in a park. This can greatly cut the costs of heating and cooling in the building below.

    Also, a green roof takes in rain water, and protects the city drainage (排水) system.   ▲    And small animals and birds can make their homes on it. Thanks to this, the city may become part of nature, rather than something completely separate from it.

    While the cost of building such a roof can still be higher, it can be cheaper in the long term as a result of energy savings. And wouldn't it be wonderful to be able to walk out into a garden high above the city's noise and traffic, whether you're at school or in an office or just at home in a ten-floor block?

    When a computer runs a group of programs, it can get very Cooling the computer can cost a lot. So some scientist's wonder what will happen if the heat from the computer can be used.

    Large Internet companies (公司) such as Google and Microsoft have thousands of computers. As these computers deal with information, they produce lots of heat, so they need huge cooling systems(系统). These systems send the heat into the air.

    A company in Holland (荷兰) thinks paying to make the computers work and then paying again to cool them are a waste of energy. So the company developed a special device—the e-radiator.

    Boaz Loupe, the head of the company, says the e-radiator works as a heating system and saves money. He explains that the energy is used twice—once to heat the home and once to cool the computer. So the users don't have to pay to cool their computers.

    Five homeowners in Holland are testing the heating system in their homes.

    "We pay for the computer using, so, in that way, homeowners get heating for free," Boaz says.

    Jan Visor is one of the homeowners. "If you use the computer more the e-radiator produces more heat," he says. "It cannot provide enough heat if you don't use your computer often. "But he is ready to try it. It's a great help for his family.

    The company says e-radiators can produce heat at a temperature of 55℃. It says the system can save its users about S 440 a year.