For hundreds of millions of years, turtles (海龟) have struggled out of the sea to lay their eggs on sandy beaches, long before there were nature documentaries to celebrate them, or GPS satellites and marine biologists to track them, or volunteers to hand-carry the hatchlings (幼龟) down to the water's edge lest (for fear that) they become disoriented by headlights and crawl towards a motel parking lot instead. A formidable wall of bureaucracy has been erected to protect their prime nesting on the Atlantic coastlines. With all that attention paid to them, you'd think these creatures would at least have the gratitude not to go extinct (die out).

    But Nature is indifferent to human notions of fairness, and a report by the Fish and Wildlife Service showed a worrisome drop in the populations of several species of North Atlantic turtles, notably loggerheads, which can grow to as much as 400 pounds. The South Florida nesting population, the largest, has declined by 50% in the last decade, according to Elizabeth Griffin, a marine biologist with the environmental group Oceana. The figures prompted Oceana to petition the government to upgrade the level of protection for the North Atlantic loggerheads from "threatened" to "endangered"— meaning they are in danger of disappearing without additional help.

    Which raises the obvious question: what else do these turtles want from us, anyway? It turns out, according to Griffin, that while we have done a good job of protecting the turtles for the weeks they spend on land (as egg-laying females, as eggs and as hatchlings), we have neglected the years spend in the ocean. "The threat is from commercial fishing," says Griffin. Trawlers (which drag large nets through the water and along the ocean floor) and longline fishers (which can deploy thousands of hooks on lines that can stretch for miles) take a heavy toll on turtles.

    Of course, like every other environmental issue today, this is playing out against the background of global warming and human interference with natural ecosystems. The narrow strips of beach on which the turtles lay their eggs are being squeezed on one side by development and on the other by the threat of rising sea levels as the oceans warm. Ultimately we must get a handle on those issues as well, or a creature that outlived the dinosaurs (恐龙) will meet its end at the hands of humans, leaving our descendants to wonder how creature so ugly could have won so much affection.

    More and more comment(评论) sections are being shut down online.

    Autumn Phillips had had enough. On August 19, the executive editor of the Quad-City Times in Iowa, and Illinois, US visited her website, qutimes. com, and saw a story about a man who had been shot to death. When she got to the readers' comments section at the end, she was shocked by what she saw. Below the story was a growing string of comments—a racist remark about democratic( 民主的) voters, a negative comment about police...So Phillips decided to do something she had been thinking about for a long time: she shut down the comment section.

    Phillips was not alone in making such a move. Last week, NPR announced it too was closing its online comments section. The decisions don't mean that the news outlets are no longer interested in what their audiences are thinking. Both stressed their eagerness to hear from readers and listeners on social networks. But both agreed that comments had deviated from their original intention. And so they had.

    In the early days of digital journalism, comments were seen as a key part of the new media, a wonderful opportunity for strengthening the dialogue between news producers and their audiences. It was a welcome change, given that for long many news organizations were far too separated from their readers. Much more back and forth conversation seemed like healthy and welcome evolutions. Sadly, that's not the way things turned out. Rather than a place for exchanging ideas, comments sections became the home of ugly name-calling, racism and anti-women language. Besides their poisonous quality, comments seem out of place today.

    “Since we made the announcement, I've received an outpouring of responses from our readers,”she says. “I've heard from parents whose children were hurt by our online comments. I've heard from people who said they wouldn't send in letters to the editor because they were attacked so fiercely by comments, and it wasn't worth it.”

    I was never very neat，while my roommate Kate was extremely organized. Each of her objects had its place，but mine always hid somewhere. She even labeled(贴标签) everything. I always looked for everything. Over time，Kate got neater and I got messier. She would push my dirty clothing over，and I would lay my books on her tidy desk. We both got tired of each other.

    War broke out one evening. Kate came into the room. Soon，I heard her screaming，“Take your shoes away！Why under my bed！” Deafened，I saw my shoes flying at me. I jumped to my feet and started yelling. She yelled back louder.

    The room was filled with anger. We could not have stayed together for a single minute but for a phone call. Kate answered it. From her end of the conversation，I could tell right away her grandma was seriously ill. When she hung up，she quickly crawled(爬) under her covers，sobbing. Obviously，that was something she should not go through alone. All of a sudden，a warm feeling of sympathy rose up in my heart.

    Slowly，I collected the pencils，took back the books，made my bed，cleaned the socks and swept the floor，even on her side. I got so into my work that I even didn't notice Kate had sat up. She was watching，her tears dried and her expression one of disbelief. Then，she reached out her hands to grasp mine. I looked up into her eyes. She smiled at me，“Thanks.”

    Kate and I stayed roommates for the rest of the year. We didn't always agree，but we learned the key to living together：giving in，cleaning up and holding on.

    Inspired by a 9-year-old cyclist, Lauren Turner, who can only use one hand, a group of University of Guelph students has won an international award for their invention－a bike brake lever (刹车手柄) that pulls both the front brake and the back brake at the same time.

    Lauren Tuner was able to ride her bike, but not as confidently and quickly as her friends.

    “She couldn't use the front brake. She only used the back brake, but the front brake makes you stop twice as fast,” says Micha Wallace, who, with Katie Bell, Anina Sakaguchi and Andrew Morries won second prize in the James Dyson Award for their single-handed bike brake lever.

    "Lauren Turner tried the device (装置) first and she used it all last summer. She had no problems. It helped her go faster because she felt more confident in her braking abilities. She felt safer." says Wallace.

    The invention was the fourth-year design project for the four students. They designed, tested and created a prototype (模型) within a four-month period.

    When Wallace heard about the James Dyson Award on the news, she and her co-inventors entered their project in the U.K.-based contest, which rewards students designers who create products that improve the way we live. The students collected the runner-up prize－£2,000 for them and £500 for their school.

    As well, they had a chance to meet James Dyson, a U.K. famous inventor. Praising the students for their invention, Dyson says the single-handed brake lever could improve safety for all cyclists. By using both brakes at once, you could prevent the possibility of flying over the handlebars and ending up with an injury.

    The students hope to sell it to a major company. It may be used in other devices that require two hands for operation.

    The plan: turn Mars into a blue world with streams and green fields, and then fill it with creatures (生物) from the earth. This idea may sound like something from a science fiction (科幻小说), but it is actually being taken seriously by many researchers.

    This suggested future for the "red planet" will be the main topic for discussion at an international conference hosted by NASA (美国宇航局) this week. Leading researchers as well as science fiction writers will attend the event. It comes as NASA is preparing a multi billion dollar Mars research programme. "Turning Mars into a little earth has long been a topic in science fiction," said Dr Michael Meyer, NASA's senior scientist for astrobiology (太空生物学). "Now, with scientists exploring the reality, we can ask what are the real possibilities of changing Mars."

    Most scientists agree that Mars could be turned into a little earth, although much time and money would be needed to achieve this goal.

    But many experts are shocked by the idea. "We are destroying our own world at an unbelievable speed and now we are talking about ruining another planet," said Paul Murdin, of the Institute of Astronomy, Cambridge, UK. Over the past months, scientists have become increasingly confident they will find Martian life forms. Europe and America's robot explorers have found proof that water, mixed with soil, exists in large amounts on the planet.

    In addition, two different groups of scientists announced on March 28 that they had found signs of methane (甲烷) in the Martian atmosphere (大气). The gas is a waste product of living creatures and could be produced by microbes (微生物) living in the red planet's soil.

    But scientists such as Dr Lisa Pratt, a biologist at Indiana University, say that these microbes will be put in danger by the little earth project. "Before we have even discovered if there is life on Mars, we are talking about carrying out projects that would destroy all these native life forms, all the strange microbes that we hope to find buried in the soil," said Dr Pratt. This view is shared by Monica Grady, a planetary scientist at the Natural History Museum, London. "We cannot risk starting a global experiment that would wipe out the precious information we are looking for." she said, "This is just wrong."

With the summer heat becoming increasingly unbearable over the years due to climate change,the cooling load in the summertime has also been on the rise.Insulation(隔热) is currently the main solution for blocking heat from entering a building,but by applying an additional material that can delay heat penetration(渗透),it can prevent the indoor temperature from rising and in turn lower the cooling load of the building.

A research team in Korea has developed a new material for building walls that can help reduce the penetration of heat from the outside.The team directed by Dr.Sarng Woo Karng from KIST revealed that they have successfully done it through building walls by applying a phase change material(PCM).One of the most common types is paraffin oil,which is used to make candles.

A solid PCM absorbs heat as it transforms into a liquid phase,so by using a case to hold it when it is in a liquid phase without causing any leakage(渗漏),it is possible to apply them to a building wall to block heat from entering inside.

The problem,however,is that the PCM turns into liquid starting from the outermost layer,and the parts that are hot move upward,while the parts that are still relatively cool move downward.Thus,while the upper part may have completely melted,the lower part will have not,and as a result,heat will penetrate into the building through the area where the PCM is in a liquid phase.In the end,the PCM becomes ineffective in controlling the indoor temperature and is rendered useless.

Dr.Karng's team addressed the non-uniform phase change with bubble injections.Injecting bubbles into the bottom part of the PCM enabled uniform circulation(流动)of the PCM in a liquid phase.Dr.Karng said,"We expect that the insulating wall using the PCM bubble generator used in this study will contribute to reducing the amount of energy used to heat or cool a building.Insulation techniques using the PCM help reduce heat penetration,in combination with the building insulating material,and it can also be used as the outer walls of zero-energy buildings."