People have been raising pigeons (鸽子) for about 10,000 years. And pigeon keepers use different kinds of pigeons for different1. Some people use pigeons for2. For example, in parts of the world, people cook a special meal with pigeon to celebrate the New Year. Some people also3pigeons because they look especially 4. There are many interesting kinds of “pretty” pigeons. Different kinds of pigeons have interesting features (特点)5 long, soft tails or designs on their heads. The6of these kinds of pigeons enter them in7and the best looking pigeons are chosen to win prizes.
But pigeons have many other8too. Pigeons can fly a long way without growing9. They also have another10sense.No matter how far from home they are, pigeons can usually fly back to where they11. This is often called a “homing sense”. This sense makes them good for carrying 12.
In many cities around the world, pigeons live in special houses,13pigeon keepers spend a lot of money and time14their birds. When someone has a very good pigeon, he is very15. He may also have a way to make money. But this is not usually the main16people keep pigeons. For some people, they keep pigeons as a hobby.
People17their pigeons so much that they even take them18when they move to a new country. They19these birds as their children. “When you are looking at a pigeon in the sky you feel20. It is the best feeling you have in a strange country,” a pigeon lover says.
Imagine loving someone so much that you'd swim more than 5, 000 miles to see him or her. Dindim manages to swim that far every year to 1 his friend Joao. This is 2 not only because of the love between the two friends, but because Dindim is3a penguin. Joao found Dindim covered in oil, barely 4on a beach near his home. He picked him up, cleaned him off and brought him to his house where he 5 him and got him healthy again. Joao named him Dindim.
After a week, he 6 the penguin back to the beach and tried to release him,7 Dindim refused to leave Joao. They 8 together for the next eleven months. Then, Dindim disappeared.9 Joao thought he'd never see his friend again. But just a few months 10 Dindim was back. He found Joao on the beach, and followed him home. Each year he 11four months to live with other penguins. For the other eight months, he lives with Joao. Joao says that each time they meet again, Dindim seems 12 to see him. He says he loves the penguin as if he were his own 13 He feels certain that Dindim loves him in the14way. Ecologist Carl Safina says that animals can and do love humans. He writes and speaks a lot about animals and their 15. According to Carl, it's obvious that animals feel love for humans. What's less obvious is whether or not humans love animals enough to 16 them. Hundreds of thousands of animals are 17 by the same oil that covered Dindim when Joao found him.
Fifty percent of 18 has disappeared in the last 40 years because of humans'19 their habitats. Scientists say we're in a new mass extinction period. In the next two 20 they predict that we'll lose 75 percent of the remaining species on earth.
I fell in love with Yosemite National Park the first time I saw it, when I was 13. My parents took us there for camping. On the way out, I asked them to wait while I ran up to E1 Capitan, a 1rock of 3,300 feet straight up. I touched that giant rock and knew2I wanted to climb it. That has been my life's passion ever since— 3the rocks and mountains of Yosemite. I've long made Yosemite my 4.
About 15 years ago I started seeing a lot of 5, like toilet paper, beer cans, and empty boxes, around the area. It's 6me why visitors started respecting the place 7and treated such a beautiful home-like place this way.
I tried 8trash (垃圾) myself, but the job was too big. I would9an hour or two on the job, only to find the area trashed all over again weeks later. Finally, I got so10it that I decided something had to change.
As a rock-climbing guide, I knew 11about organizing any big event. But in 2004, together with some climbers, I set a date for a 12. On that day, more than 300 people 13. Over three days we collected about 6,000 pounds of trash. It was amazing how much we were able to 14. I couldn't believe the15we made—the park looked clean!
Each year volunteers come for the cleanup from everywhere. In 2007 alone, 2,945 people 1642,330 pounds of trash.
I often hear people 17about their surroundings. If you are one of them, I would say the only way to change things is by 18rather than complaining. We need to teach by 19. You can't blame others 20you start with yourself.
Do you think you have what it takes to be a successful scientist? A successful scientist is generally a good observer. He makes full 1 of the facts he observes. He doesn't accept ideas which are not 2 on obvious facts, and therefore3 to accept authority as the only reason for truth. He always checks ideas 4 and makes experiments to prove them.
The rise of 5 science may perhaps be considered to 6 as far back as the 7 of Roger Bacon, the wonderful philosopher of Oxford, who lived 8 the years 1214 and 1292. He was probably the first in the middle ages to suggest that we must learn science 9 observing and experimenting on the things around us, and he himself 10 many important truths.
Galileo (15641642), however, who lived more than 300 years later, was the greatest of several great men in Italy, France, Germany, and England, 11 began to show how many important 12 could be discovered by observation by degrees. Before Galileo, learned men believed that large bodies fell more 13 towards the earth than small ones, 14 Aristotle said so. But Galileo, going to the 15 of the Leaning Tower of Pisa, let fall two 16 stones and proved Aristotle was wrong. It was Galileo's 17 of going direct to nature, and proving our 18 and theories by experiment, that has led to all the discoveries of modern science.
What 19 those people good scientists? From the example of Galileo, we know it clearly that successful scientists are those whose observations have 20 better results.
Technology is playing a vital role in preservation and ecology research. Drones (无人机) hold huge 1 in the fight to save the world's remaining wildlife from extinction. So researchers can now track wild animals through dense forests and monitor whales in vast oceans. It's estimated that up to five living species become extinct every day, making it urgent that universities develop new technologies to capture the data that can persuade 2 to act.
The British International Education Association hosted a conference in January to 3 the importance of technological solutions in protecting vulnerable (易受伤害的) species and ecosystems. Speakers underlined how technology can help 4: drones can circle high above the ocean to spot whales, while certain cameras can identify members of an individual species.
According to Claudio Sillero, biology professor at Oxford University, technology is changing how preservation research is done — but it's in a(n) 5 way. As technology gets better and cheaper, researchers become better at doing what they were already doing. 6, remote sensing used to be a very technical tool but is now widespread, and everyone uses global positioning system (GPS) for surveying.
But teaching preservation and ecology courses in university 7. Some teach drone surveying methods in depth while others don't even mention them. "The fact is, using drones is quite a(n) 8 to the interdisciplinary (跨学科的) 'unknown' of engineering, and potentially an area where lecturers may not feel confident to teach yet," Serge Wich, an expert in primate biology says. "Students are taught about 9 technologies such as automatic sound recorders, but drones are often missing from university teaching. Consequently, drone use among researchers is still fairly 10 and focused on getting photos."
Wich's team of researchers used techniques to develop a fully automated drone technology system that 11 and monitors the health of endangered animals globally. It's designed to be cheap, stable and simple to use, so that local communities in developing countries can operate it 12 without technical background. Yet it's not more widely used on the grounds of researchers' lack of skills to use this technology. In biology, where drones are used, few can program an algorithm (算法) specifically for their preservation or research problem. "There's much that needs to be done to 13 those two worlds and to make AI more user-friendly so that people who can't program can still use the technology," Wich says.
14, the sad truth is that better technology alone will not save any more species from dying out, Greengrass warns. "As human populations increase, so do threats and pressure on wild places. Preservationists are 15 for not doing enough but it's often an issue of people, conflict and governance." Technology may help provide far greater knowledge, but governments still need to act.
Students in Caldwell, Idaho, can attend class in their pajamas(睡衣)! At Vallivue Virtual Academy, courses are taught online. Students work at home with parents, who serve as learning coaches. A certified teacher 1 the students' progress.
The cyber school was 2 as a free option for students in kindergarten through grade 8 who have trouble succeeding in the district's 3 public school. Supporters of the program say that virtual schools help students avoid the social pressures that can 4 with learning. In addition, supporters argue, online courses provide kids with more focused 5 and course options than they can get in a typical school.
Not everyone gives cyber schools a passing grade, however. Some educators argue that online learning makes it hard for students to make friends. Many parents also feel that cyber schools put 6 time demands on them because they have to oversee their kids' daily work.
Technology can benefit education, but it shouldn't 7 education. Students who go to virtual schools will miss many of the benefits of being in a real school.
If kids attend school online, they will miss out on important social 8. Payton Mcdonough, 13, a seventh grader from Glencoe, Ill., agrees. "I don't know how I could sit at a computer all day without 9 interacting with my peers and teachers," he says.
In addition, virtual schools don't have enough structure. Students who take online courses can set their own schedules, which will cause problems for students who have trouble staying 10.
Furthermore, online schooling puts stress on parents because they have to 11 what their kids do at home. Many parents have full–time jobs. How are they going to run their children's education,12 in their jobs, and take care of their other responsibilities at home?
Virtual schools will make it harder for students to learn and will put too much pressure on parents.
Virtual learning does not need to replace classroom learning 13, but it can help students work at their own pace. If students struggle with subjects, they can take those courses online and spend more time on them. Virtual schools can also offer students much more 14 schedules. Students often handle extracurricular activities, sports, and schoolwork, and cyber schools could help them manage everything.
Finally, attending virtual school can prepare students for college and for work after 15. "We need to be responsible for working on our own," says Angela Goscilo, a senior from Pound Ridge, N.Y. "We need to develop technology skills that will help us in whatever we do. Getting an early start is a good idea."
What's all this tree一 planting for?" I was asked when I began writing about 1 a piece of land I had bought in Somerset. The truth is, I just love trees. And I am not 2. As I get older, all I really 3 is to plant trees, Prince Charles says in a BBC documentary in which he is 4 in the wood he planted on the day Prince George was born.
There are 5 and wonderful trees in our cities and villages. They were planted, or self- sown, years, even centuries ago. We take them for granted, 6 the creatures living among them, remain in ignorance of the 7 trees are doing us(cleaning the air, for instance) and cut them down for new 8. Yet we keep a feeling of 9 for them. This may account for the 10 the government faced in 2010 when it sought to sell off publicly owned woods, and for the wide support that the Woodland Trust (a tree-protecting charity) 11.
Trees need 12, which is why I, a city-resident, bought my Somerset woodland in 1999. At that time, climate change was already well proved, 13 my hopes of planting long-lived oaks and pines gradually developed into anxiety about their 14. Tree diseases new to the UK, wind, drought and flood were all 15 against them.
But I did not 16 things to move so fast. The woodland is still good, the new trees are growing like mad, but the creatures are 17. The rabbits have disappeared and the owl has moved. The bees and butterflies are 18 there but in smaller numbers. How can this happen on land 19 pesticides (杀虫剂)？Surely, it indicates we need to give nature the chance to restore its own 20. Meanwhile, I love my wood, and so do many of its visitors. And tree-planting has done wonders for restoring my balance town and country.
One day in winter, a couple of good friends headed for a frozen lake nearby to skate on ice. The boys were between five and ten years old. When they were skating, one of the boys headed deeper into the lake, but 1 he found himself skating on very 2 ice. Before he could 3 it, he had fallen through the ice into the icy water below. Having seen this, his friends 4 towards him but could not get him out of the lake 5 the ice layer had formed back and the boy was 6 under the transparent layer. They could see him 7 but could do nothing to help him. Then one of his friends 8 to see a tree in the distance. He skated to it as fast as he could, 9 a branch and then with all his 10 he started digging into the ice. His work proved 11 and he managed to make a hole 12 enough to pull his friend out.
By the time the ambulance arrived, a small crowd had gathered. They were all 13 the rescuer for his 14 and calmness. However, they were all surprised as well, and 15 how a young boy could break such a big branch. 16, the branch was bigger and heavier than what a person of that age group could carry, drag it to the spot and 17 it again and again to hammer a hole in the ice. It looked like a superhuman 18. How? How did he manage to do it? It was impossible! During the 19, an old man spoke up, "I know how he did it." Everybody looked at him in 20. The old man said, "He could do it because there was nobody around him who said he couldn't!"
Molecular biologist Elizabeth Blackburn shared a Nobel Prize for her research on telomeres (端粒)—structures at the tips of chromosomes (染色体)that play a key role in cellular aging. 1 she was frustrated that the important health implications of her work weren't reaching beyond academia.
So along with psychologist Elissa Epel, she has published her findings in a new book 2 a general audience -- laying out a scientific case that may give readers3 to keep their new year's resolutions to not smoke, eat well, sleep enough, exercise regularly, and 4stress.
The main message of The Telomere Effect, being published Tuesday, is that you have more control over your own aging than you may imagine. You can actually 5 your telomeres—and perhaps your life—by following sound health advice, the authors argue, based on a review of thousands of studies.
"Telomeres listen to you, they listen to your 6, they listen to your state of mind," said Blackburn, president of the Salk Institute for Biological Studies in La Jolia, Calif.
Telomeres sit at the end of the strands of DNA, like the 7 caps on shoelaces. Stress from a rough lifestyle will shorten those caps, making it more likely that cells will 8 dividing and essentially die.
Too many of these cells accelerate9, the pair say. This doesn't cause any particular disease, but research suggests that it speeds up the time when whatever your genes have in store will occur -- so if you're 10 to heart disease, you're more likely to get it younger if your telomeres are shorter, said Epel, director of the University of California, San Francisco's Aging, Metabolism and Emotions Center.
"We can provide a new level of specificity and tell people more precisely with clues 11from telomere science, about what exactly 12 is related to long telomeres, what exact foods are related to long telomeres, what aspects of sleep are more related to long telomeres," Epel added.
Other researchers in the field praised Blackburn and Epel's efforts to make telomere research relevant to the general public, 13 several warned that it risked 14 the science.
"I think it's a very difficult thing to prove that lifestyle can affect telomere length and therefore lifespan," said Harvard geneticist and anti-aging researcher David Sinclair. "To get cause-effect in humans is 15, so it's based on associations."
Trees have always held much attraction for people. They are the 1 and biggest life-forms on our planet and one of the most beautiful. As a direct 2with thousands of years of history, trees appear in many religions and have 3 artists over the years.
When I was a child I 4a science fiction story that made me think about trees in a new way. In the story, 5 from an advanced civilization come to our planet and their spaceship 6in the middle of a forest. The aliens (外星人) have a long 7with the trees of the forest and then leave, 8to think that the inhabitants (居民) of Earth are noble, intelligent and peaceful.
Trees 9a lot about being part of a community and how cooperation is better for a society than 10. Scientists are only just beginning to understand how it all 11, but we now know that trees growing together share all of the available resources (资源) with each other. So, strong trees in a good 12 will share food and water with 13 trees that receive less sunlight. By 14, a community of trees makes itself stronger. The 15of giant redwood trees, for example, grow together under the ground. It's as if they are 16hands. This means that they are 17stronger when there are heavy winds or floods.
We all acknowledge that trees are 18 for the environment and the survival of our 19. Perhaps they have even more to 20 us in the future.
Some animals live in families. Some live in great big groups. And others live mostly by themselves. Animals have to find the right 1 of living so they can stay safe, take 2of their babies, and find food.
A giant panda3eats bamboo, and it takes lots of bamboo to fill up a panda! To make sure there's enough bamboo for everyone, each panda has a territory where it lives alone, except during mating(交配) time or when a mother is 4 her baby.
Lions are hunters. 5, they live in groups. On the African plains, finding enough animals to eat is no problem. But 6 them is. Lions have better luck when they hunt 7.
Eagles live and hunt together in lifelong8. A male and a female both help to 9 a nest of sticks and twigs(小枝条), lined with 10 grasses. When the eggs hatch, one parent 11 at home to protect the young eagles while the other searches for mice or fish to eat.
Tigers are stealthy hunters who sneak up on prey such as deer or wild pigs—then pounce! But hunting is12.It can take 10 tries before a tiger gets a meal. Living 13 means there's enough prey to eat and makes quiet hunting easier.
Herds of muskoxen crowd together for 14. If a wolf comes too close, cousins, aunts, and uncles form a tight 15, with their sharp horns(角) facing outward and their young safe inside.
What brings ladybugs(瓢虫) together? It's time to hibernate for the winter by bunching together, and then the ladybugs keep each other warm.
We're encouraged to be nice to other people. However, many people 1 to be nice to the environment. Nature has 2 the alarm and global warming is quite a big 3 today in the 21st century. Carbon dioxide is the largest pollutant. That 4 causes greenhouse gases to stay in the earth's atmosphere, 5 the temperature of the globe, causing abnormal weather and melting glaciers in the north and south.
Simple things we can do every day can help 6 the earth, prevent the extinction of animals such as the polar bear, and make the earth a 7 place to live in for us and future generations to come.
I've found tons of carbon dioxide are sent out by cars every day, 8 to the climate crisis. So I decide to take 9 now to publicize the danger of carbon dioxide, or 10 do something worthwhile to help slow the rise of the weather.
There are many ways for me to help reduce global warming. I often choose public 11, buses, for example. This can 12 money and energy. I prefer to bike or walk whenever I can. Somehow, I've 13 my body and grown muscles 14 the preference. If I have to go to a place and I can't walk, I'll share a car with others. I feel very 15 that New York city has decided to popularize hybrid (混合的) buses.
I also try to 16 friends and family to do the same in order to reduce carbon dioxide release. If everyone does something to help, together we can make a 17.
People who are interested can visit the 18 www.environmentaldefense.org to work with me. I'm 19 for everyone's support and let's fight together to make the earth healthy, 20 and free from pollution.
Modern inventions have speeded up people's lives amazingly. Motor cars1 a hundred miles in more than an hour, aircraft cross the world within a day, 2 computers operate at lightning speed. Indeed, this love of 3 seems never-ending. Every year motor cars are produced which go even faster and each new computer boasts (吹嘘) of 4 precious seconds in handling tasks.
All this saves time, but5 a cost. When we lose or gain half a day in speeding across the world in an airplane, our bodies tell us so. We get the uncomfortable feeling known as jet-lag ( 时差). Our bodies feel that they have been 6 behind in another time zone. Again, spending too long at 7 results in painful wrists and fingers. Mobile phones also have their dangers, according to some scientists; too much use may transmit (传播) harmful 8 into our brains, a consequence we do not like to 9 about.
However, how do we handle the time we have saved? Certainly not relax, or so it seems. We are so used to constant activity that we find it 10 to sit down and do nothing or even just one thing at a time. Perhaps the days are long gone when we might listen 11 to a story on the radio, letting imagination take us into another world.
There was a time 12 some people's lives were devoted simply to the cultivation (耕作) of the 13 or the care of cattle. No multi-tasking (多重任务) there; their lives went on at a much gentler pace, and in a familiar pattern. There is much that we might envy about a way of life like this. Yet before we do so, we must think of the hard tasks our ancestors 14. Modern machines have 15 people from that primitive existence.
Trackers on Ice
Just because a scientist puts a GPS tracking collar on a wild polar bear does not mean the animal will willingly keep it on. 1, these huge collars are purposefully loose so that if one becomes annoying, a bear can 2it. But scientists have now found a way to use signals from the discarded(丢弃的)devices.
"These dropped collars3would have been considered garbage data," says Natasha Klappstein, a polar bear researcher at the University of Alberta. She and her colleagues instead used4from such collars, left on sea ice in Canada's Hudson Bay, to track the ice itself. For their study, published in June in The Cryosphere, the researchers 5twenty collars that sent movement data consistent(与······一致的)with ice drift rather than polar bear 6between 2005 and 2015. The resulting records of how melting ice typically drifts in Hudson Bay are unique; there are no easily 7on-the-ground sensors, and satellite observations often cannot 8capture the motion of small ice sheets.
The team compared the discarded collars' movements with widely used ice-drift modeling data from the U.S. National Snow and Ice Data Center (NSIDC). Collar data indicated that the NSIDC model underestimates the speed at which ice moves around in Hudson Bay--as well as the overall 9of drift. Over the course of several months the model could drift away from an ice sheet's location by a few hundred kilometers, the researchers say.
This means the bears may be working harder, when moving against the direction of the ice, than scientists had 10 ."Since we're underestimating the speed of drift, we're likely underestimating the energetic effort of polar bears," says Natasha Klappstein. The research reveals11insight (洞悉) into how highly mobile ice moves. As melting increases in coming years, such ice will likely become more 12farther north, in the central Arctic. Scientists had known NSIDC data could underestimate drift speeds, but "any time we can find a data 13, it is a good thing."
Plus, such data could improve predictions about how oil spills or other pollutants may spread in seas 14 with drifting ice, says Walt Meier, a senior NSIDC research scientist, who was not involved in the study. The findings may even 15future NSIDC models. "It's a really nice data set," Meier says." And certainly one we'll take consideration.
Placebos (安慰剂) Prove Powerful
Many doctors know the story of "Mr. Wright". In 1957 he was diagnosed with cancer, and given only days to live. He had tumours (肿瘤) the size of oranges. He heard that scientists had discovered a new medication, Krebiozen, that was 1 against cancer, and he begged the doctor to give it to him. His physician, Dr Phillip West, finally agreed. After Mr. Wright had been given an injection on a Friday afternoon, the 2doctor found his patient out of his "death bed", joking with the nurses the following Monday. "The tumours", the doctor wrote later, "had 3 like snow balls on a hot stove."
Two months later, Wright read medical reports that the medication was fake. His condition immediately got worse again. "Don't 4 what you read in papers," the doctor told Wright. Then he injected him with what he said was "a new super-refined double strength" version of the drug. 5, there was no drug, just a mix of salt and water, but again it worked. Wright was the picture of health for another two months until he read an official report saying that Krebiozen was 6. He died two days later.
This story has been 7 by doctors for a long time, dismissed as one of those strange tales that medicine cannot explain. The idea that a patient's 8 can make a fatal disease go away has been thought of as too strange. But now scientists are discovering that the placebo effect is more powerful than anyone had ever thought. They are also beginning to discover how such miraculous results are 9. Through new techniques of brain imagery, it can be shown that a thought, a belief or a desire can cause chemical processes in the brain which can have powerful effects on the 10. Scientists are learning that some body reactions are not caused by information coming into the brain from the outside world, but by what the brain 11 to happen next.
Placebos are "lies that 12," said Dr Anne Harrington, a historian of science at Harvard University. "The word placebo is Latin for "I shall please" (or I shall make you happy) and it is typically a treatment that a doctor gives to 13 patients to please them," she said. "It looks like medication, but has no healing ingredients whatsoever." Nowadays, doctors have much more powerful medicines to fight disease. But these treatments have not diminished (减弱) the power of the placebo, quite the 14. Maybe when scientists fully understand how placebos work, the powerful healing effects of the human 15will be used more systematically!
Mice are at their best at night. But a new analysis suggests researchers often test the nightly creatures during the day, which could alter results and create 1 across various studies, if they record time-of-day information 2. Scientists assume that waking up lab mice in the daytime may twist research.
Of the 200 papers examined in the new study, more than half cither failed to report the timing of behavioral testing or did so 3. On the contrary, they found only 20 percent reported 4 testing. The analysis was published in Neuroscience & Bio-behavioral Reviews.
West Virginia University neuro-scientist Randy Nelson, the study's lead author, says this is likely a matter of human 5. "It is easier to get students and schools to work during the day than at night," Nelson says. But that advantage 6.
"Time of day not only impacts the intensity of many 7, including mice activity, aggressiveness of their behavior, and hormone levels," but changes in those factors can only be 8 during certain parts of the daytime cycle, says University of Wyoming behavioral neuro-scientist William D. Todd. This means that "failing to report time of day of data collection and tests makes 9 of results extremely difficult," adds Beth Israel Deaconess Medical Center staff scientist Natalia Machado. Neither Todd nor Machado was involved in the new study.
10, the study researchers say it is critical that scientists report the timing of their work and consider the fact that animals' behavioral and physiological responses can 11 with the hour. As a first step, Nelson says, "obviously, taking time-of-day into consideration seems like 12 fruit in terms of line assing behavioral neuroscience research reliability, reproducibility and rigor (严谨性)
University of Calgary psychologist Michael Antle, who was also not involved in the analysis, says such differences in how studies are run 13 a "reproducibility crisis" in science, with other laboratories unable to 14 study results. "Running a study at the wrong time," he says, "could lead to us completely 15 a finding altogether."
When you are stuck on a problem, sometimes it is best to stop thinking about it—consciously, anyway. Research has shown that taking a break or a nap can help the brain create1to a solution. Now a new study2on the effect of this so-called incubation（潜伏期）by using sound cues to focus the sleeping mind on a targeted problem.
When humans sleep, parts of the brain replay certain memories, strengthening and transforming them. About a decade ago researchers developed a technique, called targeted memory reactivation（TMR）, aimed at further enhancing3memories: when a sound becomes associated with a memory and is later played during sleep, that memory gets4. In a study published last November in Psychological Science, scientists tested whether5the memory of a puzzle during sleep might also improve problem-solving.
About 60 participants visited the laboratory before and after a night of6. First, they7spatial, verbal and conceptual puzzles, with a distinct music clip repeating in the background for each, until they had worked on six puzzles they could not solve. Overnight they wore electrodes（电极）to detect slow-wave sleep, which may be important for memory enhancement—and a device played the sounds 8to three of the six unsolved puzzles. The next day, back at the lab, the participants attempted the six puzzles again. (Each repeated the experiment with a different set of puzzles the following night.) All told, the subjects solved 32 percent of the sound-stimulated puzzles compared with 21 percent of the 9puzzles.
The researchers "very bravely went for quite complex tasks that involved a lot of complex processing, and remarkably they found these really strong effects in all of their 10." says Penny Lewis, a psychologist at Cardiff University, who was not involved in the research. "These are supercool results. Now we need to go out and try to understand them by firstly replicating（复制）them and secondly trying to 11the component processes that are actually being influenced."
Beyond providing new evidence that humans restructure memories while sleeping the research may have 12implications. "In a futuristic world, maybe TMR could help us use sleep to work on our problems," says lead author Kristin Sanders, who was a graduate student at Northwestern University during the study. Sleep-monitoring technology is increasingly accessible—and even without devices, prospective solvers can focus on important problems before 13.
Still, sleep is not 14; people need to do their homework and load their heads with the puzzle pieces involved. "I'm not going to solve cancer with this technique," Sanders says, "because I am totally 15cancer research."
Space exploration has always been the province of 1: The human imagination readily soars where human ingenuity (聪明才智) struggles to follow. A Voyage to the Moon, often cited as the first science fiction story, was written by Cyrano de Bergerac in 1649. Cyrano was dead and buried for a good three centuries 2the first manned rockets started to fly.
In 1961, when President Kennedy declared that America would send a man to the moon by the3's end, those words, too, had a dreamlike quality. They resonated with optimism and ambition in much the same way as the most famous 4 speech of all, delivered by Martin Luther King Jr. two years later. By the end of the decade, both visions had yielded concrete results and5American society. And yet in many ways the two dreams ended up 6each other. The fight for racial and economic equality is intensely pragmatic (讲求实用的) and immediate in its impact. The urge to explore space is just the opposite. It is figuratively and literally otherworldly in its 7.
When the dust settled, the space dreamers lost out. There was no grand follow-up to the Apollo missions. The technologically compromised space shuttle program has just come to an end, with no8. The perpetual argument is that 9 are tight, that we have more pressing problems here on Earth. Amid the current concerns about the federal deficit, reaching toward the stars seems a dispensable luxury—10 saving one-thousandth of a single year's budget would solve our problems.
But human ingenuity struggles on. NASA is developing a series of robotic probes that will get the most bang from a buck. They will serve as modern Magellans, 11out the solar system for whatever explorers follow, whether man or machine. On the flip side, companies like Virgin Galactic are plotting a bottom-up assault on the space dream by making it a reality to the public. Private spaceflight could lie within 12 of rich civilians in a few years. Another decade or two and it could go mainstream.
The space dreamers end up benefiting all of us—not just because of the way they expand human knowledge, or because of the spin-off 13 they produce, but because the two types of dreams feed off each other. Both Martin Luther King and John Kennedy appealed to the idea that humans can 14what were once considered inherent limitations. Today we face seeming challenges in energy, the environment, health care. Tomorrow we will transcend these as well, and the dreamers will deserve a lot of the credit. The more evidence we collect that our species is 15greatness, the more we will actually achieve it.
In Botswana, farmers let their cattle feed on the grasslands surrounding the banks of the Okavango River. This area is full of 1 , including hungry lions and other big cats which often rely on surprise to approach quietly and 2 their prey (猎物).
Farm animal 3 can be economically disastrous for these often poor farmers, and their fight-back killings in response is a major 4 of population decline in large cats.
But what if there were a 5 thing farmers could do to 6 their losses? The idea came about of painting eyes on the backsides of cows to 7 lions into thinking they've been seen by their would-be prey. And once seen, these cats often 8 the hunt.
This visionary solution was 9 by nature. A number of animal species have 10 eyespot markings that prevent their 11 enemies from hunting them—some frog backsides have eyespots, as do the back ends of some fish.
Probably the most famous 12 is on butterflies. They have eyespots in their wings, and these discourage hunters such as birds from attacking them.
Even humans are 13 by eyespots: one study found that people are less likely to steal bikes when an image of 14 eyes is displayed nearby.
Over the four-year-long trial, researchers found that not one of the hundreds of cows with eyespots on their backsides was 15 by an animal hunter.
You can actually catch a good mood or a bad mood from your friends, according to a recent study in the journal Royal Society Open Science. But that shouldn't stop you from 1 with pals who are down in the dumps, say the study authors. 2, the effect isn't large enough to push you into depression.
The new study adds to a growing body of research suggesting that happiness and sadness—as well as lifestyle and behavioral factors like smoking, drinking, obesity, fitness habits and even the ability to concentrate—can 3 across social networks, both online and in real life. But while many 4 studies have only looked at friendship data at one point in time, this is one of the few that measured social and mood changes over time.
The new research involved groups of junior-high and high-school students who took part in 5 screenings(筛查) and answered questions about their best friends, many of whom were also enrolled in the study. In total, 2,194 students were included in the 6, which used a mathematical model to look for connections among friend networks.
Overall, kids whose friends suffered from bad moods were more 7 to report bad moods themselves and they were less likely to have improved when they were screened again six months to a year later. When people had more happy friends, 8, their moods were more likely to improve over time.
Some symptoms related to depression-like helplessness, tiredness and loss of interest-also seemed to follow this 9, which scientists call "social contagion." But this isn't something that people need to 10, says lead author Robert Eyre, a doctoral student at the University of Warwick. Rather, it's just a "11 empathetic (感同身受的) response that we're all familiar with, and something we recognize by common sense," he says. In other words, when a friend is going through a rough period, it makes sense that you'll feel some of their 12, and it's certainly not a reason to stay away.
The study also found that having friends who were clinically depressed did not 13 participants' risk of becoming depressed themselves. "Your friends do not put you at risk of illness," says Eyre, "so a good course of action is simply to 14 them." To boost both of your moods, he suggests doing things together that you both 15 and taking other friends along to further spread those good feelings, too."
