“Plants were expected to get larger with increased carbon dioxide in atmosphere, but  changes in temperature, humidity and nutrient availability seem to trumped the benefits of  increased carbon dioxide，” said researchers from the National University of Singapore.

    45 percent of the species studied now reach smaller adult sizes than they did in the past. The  researchers pointed out that warmer temperatures and changing habitats, caused by climate  change, are possible reasons for shrinking creatures.

     “We do not yet know the mechanisms involved, or why some organism are getting smaller while others are unaffected，” the researchers said. “Until we understand more, we could be risking negative consequences that we can't yet quantify.”

    The change was big in cold­blooded animals. Only two decades of warmer temperatures were enough to make reptiles smaller. An increase of 1 degree centigrade caused nearly a 10 percent increase in metabolism (新陈代谢). Greater use of energy resulted in tiny tortoises and little lizards. Fish are smaller now too. Though overfishing has played a part in reducing numbers, experiments show that warmer temperatures also stop fish growth. There is a recent report on warmer temperatures' negative effects on plankton, the base of the marine ecosystem.

    Warm­blooded animals weren't immune from the size change caused by climate change. Many birds are now smaller. Mammals have been miniaturized too. Soay sheep are thinner. Red deer are weaker. And polar bears are smaller, compared with historical records.

    This is not the first time this has happened in Earth's history. 55 million years ago, a warming event similar to the current climate change caused bees, spiders and ants to shrink by 50 to 75 percent over several thousand years. That event happened over a long time than the current climate change.

    The speed of modern climate change could mean organisms may not respond or adapt quickly enough, especially those with long generation times. So, it is likely that more negative influences of climate change will be shown in future.

    See a cellphone cover that you like on Taobao? Forget about placing an order, paying the bill online and waiting for days for it to be delivered to you. In the near future, you'll be able to get it in minutes just by hitting “print” on your computer.

    You might find it hard to believe that you could actually “print” an object like you would a picture. But it is not that hard to understand how it would work. Just as a traditional printer sprays ink onto paper line by line, modern 3D printers spread material onto a surface layer by layer, from the bottom to the top, gradually building up a shape.

    Instead of ink, the materials the 3D printer uses are mainly plastic, resin(树脂) and certain metals. The thinner each layer is—from a millimetre to less than the width of a hair—the smoother and finer the object will be.

    This may sound like a completely new technology, but the truth is that 3D printing has been around since the late 1980s. Back then, it was barely affordable for most people, so few knew about it.

    Last year, though, saw a big change in the 3D printing industry—printers became much cheaper. For example, 10 years ago a desktop 3D printer might have cost ￡20，000, while now they cost only about ￡1，000, according to the BBC.

    Taken out of the factory and introduced to more diverse and common uses, 3D printing can create just about anything you can think of—flutes , bikinis, jewelry, aircraft parts and even human organs. In fact, scientists from Cornell University in New York have just made an artificial ear using a 3D printer, according to Science Daily. The fake ear looks and acts exactly like a natural one.

    However, as 3D printing becomes more common, it may bring about certain problems—such as piracy. “Once you can download a coffee maker, or print out a new set of kitchen utensils (餐具) on your personal 3D printer, who will visit a retail  store again？” an expert in 3D printing told Forbes News. Even more frightening, what if anyone in the world could use a 3D printer to print out a fully functioning gun?

    Bad news sells.If it bleeds,it leads.No news is good news,and good news is no news.Those are "the classic rules for the evening broadcasts and the morning papers.But now that information is being spread amt monitored（监控）in different ways,researchers are discovering new rules.By tracking people's e-mails and online posts,scientists have found that good news can spread faster and farther than disasters and sob stories.

    "The ‘if it bleeds 'rule works for mass media,"says Jonah Berger,a scholar at the University of Pennsylvania. "They want your eyeballs and don't care how you're feeling.But when you share a story with your friends,you care a lot more how they react.You don't want them to think of you as a Debbie Downer."

    Researchers analyzing word-of-mouth communication—e-mails,Web posts and reviews,face-to-face conversations—found that it tended to be more positive than negative,but that didn't necessarily mean people preferred positive news.Was positive news shared more often simply because people experienced more good things than bad things?To test for that possibility,Dr.Berger looked at how people spread a particular set of news stories: thousands of articles on The New York Times' website.He and a Penn colleague analyzed the "most e-mailed" list for six months.One of his first findings was that articles in the science section were much more likely to make the list than non-science articles.He found that science amazed Times' readers and made them want to share this positive feeling with others.

    Readers also tended to share articles that were exciting or funny,or that inspired negative feelings like anger or anxiety,but not articles that left them merely sad.They needed to be aroused（激发）one way or the other,and they preferred good news to bad.The more positive an article,the more likely it was to be shared as Dr.Berger explains in his new book,"Contagious: Why Things Catch On."

    Hello,everybody.Welcome to surf on a new Web site—SCIENCE NEWS FOR KIDS!

    Our goal is to offer timely items of interest to kids,accompanied by suggestions for hands on activities,books, articles,Web resources,and other useful materials.

    Our emphasis is on making the Web site attractive by offering kids opportunities to comment on and grade the subject matter,get ideas for science projects,and try out math puzzles.At the same time,we offer teachers creative ways of using science news in their classrooms.

    The Science News for Kids Web site,supported by several corporations and foundations,strengthens the usefulness of Science News in the middle－school classroom and offers entertaining reading and activities for students interested in science.

    A section of the Science News for Kids Web site is devoted to particular interests.At present,we have six such zones: a weekly brainteaser（难题）for those who enjoy solving and inventing puzzles (PuzzleZone),entertaining science－fiction composition exercises for those interested in writing (SciFiZone),and weekly science short description along with science project ideas and tips (ScienceFairZone).The GameZone contains a small selection of logic and memory games.The TeacherZone has materials,including question sheets related to the feature article of the week,so that teachers can bring science news topics to the classroom.The LabZone features a weekly hands on activity or science project idea.In the future,we might add additional zones,for example,for kids interested in robotics,the environment,computers,math,or veterinary（兽医的）medicine and animals.

    Contact us at editor@snkids.com.         Science News for Kids            1719 N Street,N.W.

    Washington,DC 20036                 Phone :202-785-2255             Fax: 202-659-0365

Around the World by Wheelchair

    Rick Hansen was always an active kid and loved to fish. When returning in a truck one day from a fishing trip, he had an accident and suffered injuries to his spine (脊柱)，This 15-year-old young man awoke to find that he had lost the use of his legs. However, he didn't give up. Many months later he began to compete in wheelchair sports. At the age of 27, he decided to wheel around the world to raise awareness and money for spinal cord research. His tour took him through 34 countries around the world between 1985 and1987. In this Man of Motion World Tour, he wheeled 24,901.55 miles, which is equal to the distance around the earth.

    Bad weather and difficult, rocky roads often provided challenges for Rick, but he continued to push himself to complete the trip. He was determined to succeed. Even mountains did not stop Rick Hansen. He wheeled himself up the Rocky Mountains and several other major mountains in the world. He even wheeled himself along the Great Wall of China!

    “Never Give Up On Your Dream” was his motto and he hasn't given up yet. He completed his world tour raising $24 million. He continues to work to increase knowledge of spinal cord injury. He is a true Canadian hero who shows what determination can achieve.

We all love to take photographs. It's a simple way to snap a special moment, an amazing view, or just to show off your artistic skills. And it's great to look back through your photo albums and share memories with your friends. In fact, they show a snapshot (快照)in time. This hasn't really changed since the invention of photography in the 1830s. But one thing that has changed is the equipment we use.

For many years, we have used traditional cameras to take our pictures with. Our images were taken onto camera film which was then processed into negatives from which photos were printed— a lengthy process. And we've had a range of cameras to choose from— from the simple compact camera to more advanced single lens reflex, or SLR cameras.

But the biggest change has come with the development of digital devices. This has made taking photo quicker and easier. It's enabled us to take a snap and review our pictures instantly. We've been able to deal with them in post-production, using software on our computer. And of course, we've been able to share them like never before— particularly on social media.

Of course, now we have the smartphone— a phone that is, well, smart because it can take photos and sometimes very good quality ones, and we can share them easily. So does that mean the traditional camera will eventually become outdated? Figures from Japan show how the market is shrinking: shipments of compact digital cameras from companies like Olympus, Canon and Nikon were down 39 percent year on year.

But Phil Hall, editor of Tech Radar magazine, told the BBC that while people are swapping their compact cameras for smartphones, "manufacturers are looking at the more higher-end cameras, high-end compacts, DSLRs, which are the ones you can attach lenses to, mirrorless cameras. In this sense, there's nothing to worry about. "