科普环保类 知识点题库

    It is said that if you want to stay young, sit down and have a good think. This is the research finding of a team of Japanese doctors, who say that most of our brains are not getting enough exercise — and as a result, we are growing old unnecessarily soon.

    Professor Taiju Matsuzawa wanted to find out why otherwise healthy farmers in northern Japan appeared to be losing their ability to think and reason at a relatively early age, and how the process of aging could be slowed down. With a team of colleagues at Tokyo National University, he set about measuring brain volumes of a thousand people of different ages and varying occupations. Computer technology enabled the researchers to obtain precise measurements of the volume of the front and side parts of the brain, which controls functions like eating and breathing, does not contract with age, and one can continue living without intellectual on economical faculties. Contraction of front and side parts — as cells die off — was observed in some subjects in their thirties, but it was still not evident in some sixty-and seventy-year-olds. Matsuzawa concluded from his tests that there is a simple way to the contraction normally connected with age — using the head.

    The findings show in general terms that contraction of the brain begins sooner in people in the country than in the town. Those least at risk, says Matsuzawa, are lawyers, followed by university professors and doctors. White collar workers doing routine work in government offices are, however, as likely to have shrinking (萎缩) brains as the farm worker, bus driver and shop assistant.

    Matsuzawa's findings show that thinking can prevent the brain from shrinking. Blood must circulate properly in the head to supply the fresh oxygen the brain cells need. “The best way to maintain, good blood circulation is through using the brain.” he says. “Think hard and engage in conversation. Don't rely on pocket calculators.”

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

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

    UBC Professor Simard explains how trees are much more complex than most of us ever imagined.

    Although Charles Darwin thought that trees are competing for survival of the fittest, Simard shows just how wrong he was. In fact, the opposite is true: trees survive through their co-operation and support, passing around necessary nutrition “depending on who needs it”.

    Nitrogen (氮) and carbon are shared through miles of underground fungi (真菌) networks, making sure that all trees in the forest ecological system give and receive just the right amount to keep them all healthy. This hidden system works in a very similar way to the networks of neurons (神经元) in our brains, and when one tree is destroyed, it affects all.

    Simard talks about “mother trees”, usually the largest and oldest plants on which all other trees depend. She explains how dying trees pass on the wealth to the next generation, transporting important minerals to young trees so they may continue to grow. When humans cut down “mother trees” with no awareness of these highly complex “tree societies” or the networks on which they feed, we are reducing the chances of survival for the entire forest.

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

    Climbers at Qomolangma are being asked to clean up after themselves.

Qomolangma has earned the nickname（绰号）the World's Highest Garbage Dump（垃圾场）.

    Climbing Qomolangma,the world's highest mountain,just becomes more challenging.The government of Nepal is telling climbers they cannot leave trash on the trails.Each climber will have to come down the mountain with at the least 18 pounds of garbage.That's the average amount of trash a climber leaves behind on Qomolangma.

    Officials say climbers are responsible for their own trash.“We are not asking climbers to pick up trash left by someone else,”said the Nepal Tourism Ministry.“We just want them to bring back what they took up.”

    More than 4,000 people have reached the 29,035-foot summit（顶峰）in more than 60 years.Leaving trash along the way helps climbers keep their bags light so they have energy to reach the summit.“The trash problem in Qomolangma is not new.”Burlakoti says.“When the people started to climb the mountain,they started to leave their garbage there.”They have left behind bottles,food boxes and equipment.

    The new rule came into effect in April,2014.To make sure it is followed,climbers will have to deposit money（交保证金）before they climb.Once they climb back down the mountain,officials will check climbers at a return camp to make sure they have the required 18 pounds of trash.If they do,their money will be returned to them.If they do not,climbers will not receive their deposit and they will not be given a permit the next time they want to climb Qomolangma.

    The goal is to make sure no more litter will be left on Qomolangma."As we offer Qomolangma to all the people of the world they should take responsibility to clean it."Burlakoti says,“After seeing the results from this,we will also apply this rule to other mountains.”

    It may appear strange to hear that crops are making headlines.But this is no ordinary produce—these fruits and vegetables have been grown in simulated（模拟的）Martian and lunar soils!

    Though the possibility of growing crops in outer space only gained widespread interest after Matt Damon grew potatoes in the movie "The Martian",scientists have been testing the idea for many years.Fresh produce will after all be the key to setting up space colonies（殖民地）.

    Among the pioneers in this effort is a team led by Wieger Wamelink,a scientist at Netherland's Wageningen University.In 2013,they planted fourteen varieties of plants in simulated Martian and lunar soils.Though the "Mars" plants did not bear any produce,they grew better than the "lunar" plants,most of which died shortly after being planted.Lack of vapor in the soil,according to the scientists,might have accounted for the failure.

    The second experiment began in late 2015.The researchers selected the same crops,while this time they used larger containers and added grass to them.In March 2016,their efforts were rewarded with a variety of produce including the vegetable that kept "The Martian" alive: potatoes.

    However,the researchers were still not sure if the produce was safe to eat.That's because the Martian and lunar soils contain heavy metals like lead and arsenic,which do not affect plants but are poisonous to humans.

    After months of testing,earlier this week,the team finally confirmed that the produce was safe for human consumption.Some of the crops even contained lower levels of heavy metals than plants grown in the "ordinary" earth soil.

    To celebrate the success,the scientists held a dinner party that centered ground the crops.While there is no word on how the food tasted,it sure looks delicious.

    Air travel can be annoying. But research now suggests global warming could make it much worse. To get off the ground in really hot weather, planes may be forced to carry fewer passengers. That might mean a little more space, which would be good. However, it also would make the passengers pay more.

    Average air temperatures around the world are rising because people are polluting the air with an increasing number of greenhouse gases, which, such as carbon dioxide, are a byproduct (副产品) of burning fuels. Those warmer temperatures can influence an airplane's ability to fly because air molecules (分子) spread out more as the air warms. This produces less lift under a plane's wings, so a plane must be lighter to take off in hot weather than on cooler days.

It can even prove too dangerous for some planes to attempt a take-off. A record of June heat wave in the American Southwest, for instance, caused flight cancellations in Phoenix, Ariz. One airline's planes were cleared to operate only up to 47.8 degree Celsius. On June 20, Phoenix reached 48.3℃!

    Radley Horton is a climate scientist at Columbia University. Two years ago, he and his graduate student Ethan David Coffel studied the impact of warming at four U.S. airports and found that warming of track could triple (使成三倍) the number of days when planes face weight restrictions. Later, they explored the impact of rising temperatures on live types of commercial planes flying out of 19 of the world's busiest airports. In the coming decades, as many as one to three out of every 10 flights that take off during the hottest time of day could face weight. That would be equal to taking a dozen people off the plane, the researchers calculated.

    A new high tech mirror, designed specifically for cancer patients, will only become reflective when a user smiles into it. The plug-in device, which exactly looks like a tablet, comes equipped with a mirror, a built-in camera, and a smart material triggered(触发)by some software. Facial recognition technology captures the face and instructs the surface of the mirror to change when a smile is detected. It can hang on a wall or sit on a table, much like a conventional mirror. Unlike a regular mirror, however, the price is currently standing at a surprising $2000—$3000.

    After witnessing a close family member struggle through cancer treatments, Turkish industrial designer Berk Ilhan decided to focus his work primarily on products that would cultivate joy and benefit cancer patients directly.

    “She told me in the first days after her diagnosis, it was difficult for her to look in the mirror and acknowledge she had cancer.” he said.“ Our facial expressions affect how we feel. If we flex(绷紧)our facial muscles to smile, our brains think that something good happened and as a result, we feel happiness.”

    After earning his master's degree at the School of Visual Arts in New York, Ilhan spent several weeks visiting cancer hospitals in Turkey, speaking to both patients and doctors. He spent two years designing and developing the mirror. The idea behind it is that smiling, even when forced, can make us feel better, according to research known as the facial feedback hypothesis. Laughter is linked to improved immune system function, and some researchers claim it can even increase our lifespans.

Ilhan is currently producing the mirror in limited quantities at the previously mentioned price. The product, however, will soon be launching a campaign in which Ilhan hopes to raise enough funds to bring the price down to $500.He also intends to donate the mirror to hospitals when it is financially possible to do so.

Senses That Work Together

    When we think about how our senses work, we usually imagine them operating separately: you sniff a flower, and the smell is delivered uninterrupted from nose to brain. However, it's more complex than that. Most evidence for cross modal perception (知觉) comes from studies into sound and vision (视觉). But research that shows other senses crossing over is coming out all the time, and it seems that even sound and smell sometimes form an unlikely pairing.

    When New York researchers, Daniel Wesson and Donald Wilson, tried to find out the truth about a "mysterious” area of the brain called the olfactory tubercle, they had to deal with this fact. Originally, they only intended to measure how olfactory tubercle cells in mice responded to smell. But during testing, Wesson noticed that every time he put his coffee cup down, the mouse cells jumped in activity. In fact, the olfactory tubercle is well-placed to receive both smell and sound information from the outside world. Later they found that among separate cells, most responded to a smell but a significant number were also active when a sound was made. Some cells even behaved differently when smell and sound were presented together, by increasing or decreasing their activity.

    Of course, mice aren't people, so research team has been carrying out further experiments. They pulled together a group of people and gave them various drinks to smell. Participants were asked to sniff the drinks, and then match them to appropriate musical instruments and produce the notes at different levels. The results were interesting: piano was regularly paired with fruity fragrances; strong smells sounded like the instruments that are made of metal.

    Further research found that listening to different sounds can change your perceptions. Studying taste this time, the team ordered some special toffee (太妃糖) and put together “soundscapes” corresponding to bitterness and sweetness. Participants tasted similar pieces of toffee while listening to each soundscape, and found the toffee more bitter or sweeter, depending on which soundrack they were listening to.

    Studies like this are helping scientists correctly describe our understanding of the senses, and how the brain combines them with its advantage. The consequences are worth considering. Could we see musicians work together with chefs to produce sound-improved food and drink? Will you be ordering a coffee with a soundrack to bring out your favorite smell? Come to think of it, that could be one thing you hope coffee shop chains don't get round to.

    Honey from the African forest is not only a kind of natural sugar, it is also delicious. Most people, and many animals, like eating it. However, the only way for them to get that honey is to find a wild bees' nest and take the honey from it. Often, these nests are high up in trees, and it is difficult to find them. In parts of Africa, though, people and animals looking for honey have a strange and unexpected helper-a little bird called a honey guide.

    The honey guide does not actually like honey, but it does like the wax in the beehives(蜂房). The little bird cannot reach this wax, which is deep inside the bees' nest. So, when it finds a suitable nest, it looks for someone to help it. The honey guide gives a loud cry that attracts the attention of both passing animals and people. Once it has their attention, it flies through the forest, waiting from time to time for the curious animal or person as it leads them to the nest. When they finally arrive at the nest, the follower reaches in to get at the delicious honey as the bird patiently waits and watches. Some of the honey, and the wax(蜂蜡), always falls to the ground, and this is when the honey guide takes its share.

    Scientists do not know why the honey guide likes eating the wax, but it is very distance away. They will quickly arrive whenever a beekeeper is taking honey from his beehives, and will even enter churches when beeswax candles are being lit.

Sweet Dreams While You Sleep

    Did you sleep the day away on Friday March 21? Well, you should have done that because it was World Sleeping Day.

    This is the day of the year when people around the world care about their sleep and ask themselves questions about sleep.

    Why do we need sleep?

    Nobody as yet can give a perfect answer to this question. However, lab tests on rats have shown that lack (缺少) of sleep over about four weeks leads to a strong drop in body temperature, great weight loss and finally, death.

    How much sleep?

    Different people need different amounts of sleep. Eight hours a night is considered the average amount of sleep. For teenagers, the least number of sleeping hours advised by doctors are 10 hours for primary school students, nine for junior highs and eight for senior highs.

    Some people seem to get along just well with very little sleep at night. Leading American scientist Thomas Edison, for example thought of sleep to be a waste of time. He did, however take naps (打盹) during the day. On the other hand, Albert Einstein, another great scientist, said he needed at least ten hours sleep a night.

    How can we sleep well?

    Here are some of the most popular tips for a good night's sleep:

    Listen to your body clock, not your alarm clock (闹钟).

    Use your bed only to sleep.

    Get up and go to bed at the same time (also on weekends).

    Exercise in the morning and in the early afternoon. Don't exercise in the evening.

    Stop looking at that clock while you can't sleep! And don't worry.

    Avoid alcohol (酒精), caffeine (咖啡因) and smoking before going to bed.

    Keep the bedroom dark, quiet, and cool.

    On Nov. 24, near Yellowstone's northeast entrance, Spitfire, a female grey wolf, was shot and killed by a hunter as she approached a group of cottages.

    "It was a legal harvest," Abby Nelson, a wolf management specialist said. "The facts are obviously a little bit harder for people to bear, but that pack has showed signs of habituation. They just stand there and have no fear. Wolf hunters can easily pick the one they want."

    The carefree relation that some Yellowstone wolves have built with humans is reportedly attractive for hunters who look for an easy kill.

    In the overnight, yet another famous Yellowstone wolf met a violent end outside the park, officials are actively rethinking how to manage wildlife habituation.

    Smith, a wolf biologist for Yellowstone, says, "Now we're thinking of pounding them," Park officials might use fireworks, and paintball or beanbag guns when they approach humans in the park. "If you get close to people, you're going to get attacked."

    If you think this sounds cruel, you're not alone. Seeing these creatures from the roads that wind through the park not only allows tourists to witness something amazing, but also to reconnect with nature in a way that is better than any conservation campaign. But there's a growing sense that the present policy of doing nothing isn't working; more wolves will unnecessarily die and the broken record of hunters scoring easy kills will go on.

    As Smith adds, urging people to keep wolves wild when meeting them halfway is a big ask. Still, he's hopeful to preserve the world's best place to observe free­ranging wolves; it's a policy change that tourists can be involved in.

    "... perhaps Spitfire's death will accomplish some good, and we'll all come together to do a better job on managing crowds and roads and wolves in Yellowstone, " Smith said.

    Cli-Fi refers to "climate fiction"; it is a term invented by journalist Dan Bloom. These are fictional books that somehow or someway bring real climate change science to the reader. What is really interesting is that Cli-Fi books often present real science in a believable way. They become fun teaching tools. There are some really well known authors such as Paolo Bacigalupi and Margaret Atwood. A list of other candidate Cli-Fi novels was provided by Sarah Holding in the Guardian.

    What makes a Cli-Fi novel good? In my opinion, it has to have some real science in it. And it has to get the science right. Second, it has to be fun to read. When done correctly, Cli-Fi can connect people to their world; it can help us understand what future climate may be like, or what current climate effects are.

    One thing that is hard to imagine is the future. What will the world be like decades from now when Earth temperatures have continued to rise? What will agriculture be like? What will coastal communities be like? It is also hard to imagine what living a subsistence agriculture life is like, today. What happens to lives and communities when the rains change, or don't come at all? What would that world look like?

    One recent example of Cli-Fi literature is South Pole Station by Ashley Shelby. In this book we follow Cooper Gosling, who is traveling to a research location on Antarctica to create paintings. Yes, an artist is sent to live with researchers and crew ­ with funding from the National Science Foundation. After arriving at the South Pole, Cooper has to become acquainted with the strange social system that exists there. Ashley writes the book in such a way that you actually feel you are huddled(拥挤) in the cold with her and her co-workers.

    Would you buy a car that released calming smells into the air when you are stuck in heavy traffic? Would you buy a robot that smells like a human being?

    Many people have seen the 3-D computer-made environments of virtual (虚拟的) reality (VR). Now these virtual worlds will not just look and sound real. Researchers have created VR environments that even smell like the real things. With the new technology, users open a virtual door and step into a new environment, like a rainforest. After they enter this virtual world, special equipment releases forest-like smells into the air to make the experience seem more real.

    Suzanne Fisher-Murray said, "It is a really wonderful experience that you have because you reexploring this environment and you have smells with it."

    In the United States, Smell-O-Vision was designed to provide smells during the showing of a movie. The Smell-O-Vision system was once popular in the 1960s. Now, Emanuela Maggioni says it is close to becoming popular again. "People will be impressed by the connection with emotions, memories, and … the sense of smell," Maggioni said. "It is unbelievable what we can do with technology."

    The uses for smell technology are not just limited to films and the performing arts. Researchers showed a computer program where users could imagine themselves driving a car. The system included a special smell-spraying machine. Dmitrijs Dmitrenko said, "We want to deliver the smell of lavender (薫衣草) every time the person drives over the speed limit. We choose lavender because it's a very calming smell."

    Scientists are experimenting with smell instead of sounds or image-based warnings on telecommunications equipment. And businesses are already using smell to influence people's behavior. "Not only...in stores... But on the other side, you can create and stimulate (刺激) immediate buying," Maggioni said. "So you're in a library and you smell coffee and actually you are unconsciously having the need to drink a coffee."

    According to a new study, teens focus on rewards and have a hard time learning to avoid punishment or consider the consequences of alternative actions.

    University College London researchers compared how teens and adults learn to make choices based on the available information. They tracked the way in which 18 volunteers aged 12-17 and 20 volunteers aged 18-32 completed tasks in which they had to choose between abstract symbols.

    Each symbol was consistently associated with a fixed chance of a reward, punishment, or no outcome. As the trial progressed, participants learned which symbols were likely to lead to each outcome and adjusted their choices accordingly. Teens and adults were equally good at learning to choose symbols associated with reward, but teens were less good at avoiding symbols associated with punishment. Adults also performed significantly better when they were told what would have happened if they had chosen the other symbol after each choice, while teens did not appear to take this information into account.

    "From this experimental lab study we can draw conclusions about learning during the teen years. We find that teens and adults learn in different ways, something that might be relevant to education," said lead author Dr. Stefano Palminteri. " Unlike adults, teens are not so good at learning to adjust their choices to avoid punishment. This suggests that incentive systems based on reward rather than punishment may be more effective for this age group. Additionally, we found that teens did not learn from being shown what would have happened if they made alternative choices."

    To interpret the results, the researchers developed computational models of learning and ran simulations (模拟)applying them to the results of the study. The first was a simple model, one that learned from rewards, and the second model added to this by also learning from the option that was not chosen. The third model was the most complete and took the full context into account, with equal weight given to punishment avoidance and reward seeking. For example, obtaining no outcome rather than losing a point is weighted equally to gaining a point rather than having no outcome.

    Comparing the experimental data to the models, the team found that teens" behavior followed the simple reward-based model while adults" behavior matched the complete, contextual model. "Our study suggests that teens are more receptive to rewards than they are to punishments of equal value," said senior author Dr. Sarah-Jayne Blakemore. "As a result, it may be useful for parents and teachers to frame things in more positive terms."

    Pleasingly, a new study supports one of my favourite insights about writing, or getting any creative work done—though I'm pretty sure that wasn't intentional, since the  researchers were actually studying traffic jams. Jonathan Boreyko, an American engineering professor, was crawling along in his car one day, observing how drivers naturally bunch up at red lights, leaving mere inches between vehicles. Their motivation isn't a mystery：the closer you are to the car ahead, you'd assume, the better your chances of squeezing through before the light goes back to red, and the sooner you'll reach your destination, even if you also increase the risk of collisions.

    But you'd assume wrong. When Boreyko and a colleague recreated the traffic­light scenario(场景) on a special test track, they found that drivers who bunched up made no swifter progress. True, they stopped slightly closer to the light. But it also took them longer to resume(继续) moving safely, and these two factors cancelled each other out. "There's no point in getting closer to the car in front of you when traffic comes to a stop," Boreyko concluded.

    This is true of writing or similar work. People never rest in urgent pursuit of their goals. Yes, it all looks impressively productive. But as the psychologist Robert Boice argues, racing to get a task completed generally brings a cost that outweighs the benefit. You tire yourself out, so you can't shine the next day. Or you neglect so many other duties that you're forced to take an extra day to catch up. Or you start damaging work you've already produced—which is why the novelist Gabriel García Márquez said he gave up writing in the afternoon: he wrote more, but he had to redo it the next morning, so the overall effect was to slow him down. That's also why Boice insists that, when you're writing on a schedule, it's as important to be disciplined about stopping as starting, even if you're on a roll.

    Clearly, this is all a convenient way to feel superior to people who put in more hours. But that doesn't mean it's untrue. Indeed, it's scary to ask what role impatience plays in your life in general：how much of each day we spend leaning into the future, trying to get tasks "out of the way", always focused on the destination, metaphorically(隐喻地) inching closer and closer to the bumper of the car ahead. None of it gets us anywhere faster. It's also no way to live.

    An artist has carved a giant SOS message into an Indonesian palm oil plantation（棕榈油种植园）to draw attention to the damage done by forest destruction and stress the impact on people and wildlife.

    Emest Zacharevic created the Save Our Souls（SOS）project as part of a campaign on the impact palm oil plantations have on local communities and endangered species such as the orangutan（褐猿）. The SOS carving, which he completed last month, runs for about half a kilometer inside a plantation in North Sumatra, and can be seen from the air.

    Environmentalists say land-clearing for agricultural plantations in Indonesia, the world's biggest palm oil producer, is responsible for forest destruction-forest cover has dropped by nearly a quarter since 1990.

    Zacharevic's SOS project comes during growing pressure on companies to adopt sustainable（可持续的）practices. PepsiCo and British firm Lush have committed to ending the use of palm oil, which is found in products from soap to cereal.

    Indonesia has been a focus of global efforts to reduce greenhouse gas emissions（排放）caused by the forest destruction to make way for plantations.

    These forests are often in remote areas long occupied by native peoples, who might not have documents proving ownership or be able to contest land acquisitions in the resource-rich Southeast Asia. The forests are home to about 14,600 orangutans remaining in the wild in Sumatra.

    "We are all contributing to the destructive effect of unsustainable palm oil, whether it is by consuming products or supporting policies that affect the trade," Jacharevic said. "This project is an effort to appeal to the consciousness of a wider audience."

    If you are like most students, you probably sit still while learning a new language. However, sitting still may not always be the best way to learn. English learners can improve their language skills through movement, says Tamara Jones. She works at the English Language Center at Howard Community College in Maryland.

    So, what is the relationship between physical movement and the brain? The idea is that the brain and the body are joined together. This means that one affects the other.

    Many people are familiar with the idea that the brain tells the body to move. And many people are familiar with the idea that repeating an action over and over again helps your brain to remember. However, some research, such as a study by Morsella and Krauss, suggests that your body might help your brain to find memories. Specifically, movements we make with our body, such as hand gestures, may help us to remember and use the correct words.

    This idea is part of the reason why experts on learning strategies, which are ways to improve the learning process, suggest using movements. One learning approach, the Cognitive Academic Language Learning Approach, or CALLA, calls the use of movements "Using Your Kinesthetic (动觉的) Sense".

    Beyond helping the brain to find memories, movements also aid in learning, says Tamara Jones. There's a lot of research that suggests what you do with your body, you remember with your brain. And also, a lot of these physical movements will encourage us in class or in life, when we are practicing on our own, to repeat and repeat and repeat the word as we are doing the physical movement, and this also helps us remember the word."

Tiny as they are, bats have the ability to "see" in the dark by using a special skill called echolocation (回声定位法).They make noises and wait for sound waves, or an echo, to bounce back off objects. They can tell the distance of various objects by how quickly the sound waves bounce back off them. If no sound bounces back, they can then fly forward.

This special ability has been copied in the human world for a long time, such as in submarines and planes. But apart from helping vehicles "see" where they are, what if blind people could use echolocation for themselves? American Daniel Kish, who is blind, is known as "Batman". This isn't because he walks around in a cape (披风) and a mask, but because he has a bat-like ability to locate where he is through sharp clicks he makes by moving his tongue against the roof of his mouth. Kish is so skilled at echolocating that he can ride a bike and hike on his own.

Recently, a research carried out at the University of Durham in England shed some light on the power of human echolocation. Kish, as well as other volunteers, worked with a group of scientists who studied the way blind people listen to the echoes that they produce from clicks. The team found that people were capable of hearing even very faint echoes, ones far fainter than had been previously thought.

Lore Thaler, lead scientist of the group, said, "We found that in some conditions, they were really faint—about 95 percent softer than the actual clicks, but the echolocators were still able to sense this."

Andrew Kolarik, another expert in echolocation, told BBC News that echolocation "can be very useful at providing information at face or chest height" and could help people "avoid objects like low hanging branches that might not get detected by the cane or a guide dog"

According to BBC News, echolocation is a skill blind people can acquire and develop, just like learning a language. As Kolarik said, "Teaching echolocation skills could provide blind people with the means of exploring new places."

The snow in Antarctica is turning green and scientists say climate change may be to blame. According to a study at the Cambridge University, microscopic algae blooms (藻类爆发) across the surface of the snow is slowly turning Antarctica's winter white landscape green. Although microscopic, scientists say they’re able to see the “green snow” from space when the algae blooms all together.

Researchers created a large-scale map of green snow algae along the Antarctic coast using a combination of satellite data and on-the-ground observations over the course of two summers. The study found that the green snow algae bloomed in warmer areas where the average temperatures are just above 0℃ during the southern hemisphere's (半球的) summer months from November to February.

“As Antarctica warms, we predict the overall mass of snow algae will increase,” said Dr. Andrew Gray, lead author of the paper, and a researcher. Researchers say larger blooms of algae can be found north of the Antarctic and South Shetland Islands, where it can spread to higher ground as the snow melts.

The team also discovered some sea birds and mammals influenced the distribution of algae. Over 60% of algae blooms were found within three miles of a penguin settlement. Scientists hypothesize this may be due to their droppings, which act as a “highly nutritious fertilizer.”

“This is a significant advance in our understanding of land-based life on Antarctica, and how it might change in the coming years as the climate warms,” said Dr. Matt Davey in the University of Cambridge's Department of Plant Sciences, who led the study.

Researchers say they have translated the meaning of gestures that wild chimpanzees（黑猩猩）use to communicate. They say wild chimps communicate 19 specific messages to one another with a "vocabulary" of 66 gestures. The scientists discovered this by following and filming groups of chimps in Uganda, and examining more than 5,000 incidents of these meaningful exchanges.

Dr Catherine Hobaiter, who led the research, said that this was the only form of intentional communication to be recorded in the animal kingdom. Only humans and chimps, she said, had a system of communication where they deliberately sent a message to another group member.

"That's what's so amazing about chimp gestures," she said. "They're the only thing that looks like human language in that respect."

Although previous research has shown that apes and monkeys can understand complex information from another animal's call, the animals do not appear to use their voices intentionally to communicate messages. This was a significant difference between calls and gestures, Dr Hobaiter said.

Chimps will check to see if they have the attention of the animal with which they wish to communicate. In one case, a mother presents her foot to her crying baby, signalling: "Climb on me." The youngster immediately jumps on to its mother's back and they travel off together. "The big message from this study is that there is another species（物种）out there that is meaningful in its communication, so that's not unique to humans," said Dr Hobaiter.

Dr Susanne Shultz, an evolutionary biologist from the University of Manchester, said the study was praiseworthy in seeking to enrich our knowledge of the evolution of human language. But, she added, the results were "a little disappointing".

"The vagueness of the gesture meanings suggests either that the chimps have little to communicate, or we are still missing a lot of the information contained in their gestures and actions," she said. "Moreover, the meanings seem to not go beyond what other animals convey with non-verbal communication. So, it seems the gulf remains."

Plastic-Eating Worms

Humans produce more than 300 million tons of plastic every year. Almost half of that winds up in landfills(垃圾填埋场), and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms.

Researchers in Spain and England recently found that the worms of the greater wax moth can break down polyethylene, which accounts for 40% of plastics. The team left 100 wax worms on a commercial polyethylene shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms' chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste(糊状物) and applied it to plastic films. 14 hours later the films had lost 13% of their mass — apparently broken down by enzymes (酶) from the worms' stomachs. Their findings were published in Current Biology in 2017.

Federica Bertocchini, co-author of the study, says the worms' ability to break down their everyday food — beeswax — also allows them to break down plastic. "Wax is a complex mixture, but the basic bond in polyethylene, the carbon-carbon bond, is there as well, "she explains, "The wax worm evolved a method or system to break this bond. "

Jennifer DeBruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify the cause of the breakdown. Is it an enzyme produced by the worm itself or by its gut microbes(肠道微生物)?

Bertocchini agrees and hopes her team's findings might one day help employ the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process — not simply "millions of worms thrown on top of the plastic."