Exposing living tissue to subfreezing temperatures for long can cause permanent damage. Microscopic ice crystals (结晶体) cut cells and seize moisture (潮气), making donor organs unsuitable for transplantation. Thus, organs can be made cold for only a few hours ahead of a procedure. But a set of lasting new antifreeze compounds (化合物)—similar to those found in particularly hardy (耐寒的) animals—could lengthen organs' shelf life.

    Scientists at the University of Warwick in England were inspired by proteins in some species of Arctic fish, wood frogs and other organisms that prevent blood from freezing, allowing them to flourish in extreme cold. Previous research had shown these natural antifreeze molecules (分子) could preserve rat hearts at -1.3 degrees Celsius for up to 24 hours. But these proteins are expensive to extract (提取) and highly poisonous to some species. “For a long time everyone assumed you had to make synthetic (人造的) alternatives that looked exactly like antifreeze proteins to solve this problem, ”says Matthew Gibson, a chemist at Warwick who co-authored the new research. “But we found that you can design new molecules that function like antifreeze proteins but do not necessarily look like them.”

    Most natural antifreeze molecules have a mixture of regions that either attract or repel water. Scientists do not know exactly how this process prevents ice crystal formation, but Gibson thinks it might throw water molecules into push-pull chaos that prevents them from tuning into ice. To copy this mechanism, he and his colleagues synthesized spiral-shaped molecules that were mostly water-repellent—but had iron atoms at their centers that made them hydrophilic, or water-loving. The resulting compounds were surprisingly effective at stopping ice crystals from forming. Some were also harmless to the roundworm Caenorhabditis elegans, indicating they might be safe for other animals.

    “These compounds are really cool because they are not proteins—they are other types of molecules that nonetheless can do at least part of what natural antifreeze proteins do, ”says Clara do Amaral, a biologist at Mount St. Joseph University, who was not involved in the research. Gibson's antifreeze compounds will still need to be tested in humans, however, and may be only part of a solution. “We don't have the whole picture yet,”do Amaral adds. “It's not just one magical compound that helps freeze-tolerant organisms survive. It's a whole suite of adaptations.

    World Elephant Day is the perfect time to find out more about these amazing animals and what we can do to preserve them so they do not go the way of the mammoth（猛犸象）.

    World Elephant Day was created in 2011 by two Canadian filmmakers Patricia Sims and Thailand's Elephant Reintroduction Foundation and was first celebrated on August 12, 2012. They made the documentary Return to the Forest, a fascinating 30 minute film about the reintroduction of caught Asian elephants to the wild.

    Currently, the demand for ivory（象牙）is becoming bigger and bigger, whose price is higher than that of gold, making elephants bigger targets than ever. Habitation loss is also a danger to the world's elephant population as it robs elephants of the hundreds of pounds of food they need every day, making it more difficult for them to breed and making it easier for hunters to track them down. Circuses and tourism are also serious threats to the animals' well-being.

    The best way to celebrate this day is to take the opportunity to educate yourself about these magnificent（巨大的）mammals and share your knowledge with others. As ever, simply spreading the word about the dangers these magnificent mammals face via social media can actually make a real change. Expose that “training” elephants often involves tying and beating them daily for months on end. If you want to get a bit more involved, you could choose to make a donation to a foundation dedicated to protecting elephants from hunters or relocating them to locations better suited to their needs.

    Whichever way suits you best, make sure that you spend this day in a way that helps elephants all over the world, so we, in turn, can continue to wonder at them and their uniquely fascinating way of life.

    Wolves travel shorter distances and move slower during snowfall events, according to new research by University of Alberta biologists. The effects were most pronounced at night, when wolves hunt, and behaviour returned to normal within a day. Wolf tracks across snow in northeastern Alberta.

    "Our findings suggest that there is something about actively falling snow that causes wolves to slow down," said Amanda Droghini, a former MSc student in the Department of Biological Science and lead author on the study. "We don't know the exact mechanism behind that. It's unlikely that they were staying still because they were feasting on a recent kill. Instead, active precipitation（降雪量）might affect wolves' hunting abilities. Like rain, snow clears the air column of scent molecules. So, maybe falling snow makes it harder for wolves to detect the smell of prey."

    Over the course of two winters, the researchers used remote cameras to disclose snowfall events and estimate snow depth. To study wolf movement, they collected telemetry（测距仪） data from 17 wolves to calculate travel speed and duration, as well as resting periods. It is the first study to examine how large flesh-eating animals respond to snowfall events.

    With the effects of climate change on precipitation in the north forest region uncertain, it is difficult to predict the implications for wolf populations. Studies such as these increase our understanding of how large mammals react to normal snowfall events, but the type and amount of winter precipitation will likely have an impact on animal behavior and the energetic cost of movement.

    "Winter is already challenging for many wildlife species because moving through snow requires more energy. Snow can also make it harder for animals to access food resources," said Droghini, who conducted the research under the supervision of Professor Stan Boutin, Alberta Biodiversity Conservation Chair.

    "Anything that increases those costs, such as increased rain-on-snow events, could lead to lacking in nutrition, poor body condition, and even starvation as animals are unable to make up for those additional costs. That is one of the worst-case scenarios（设想）but, in truth, we know very little about potential changes to precipitation patterns and how wildlife will respond to those changes."

    Your next car might drive itself. After years of trials on city streets, driverless vehicles are now on the way. Last month, a driverless bus began carrying passengers through Lyon, France. Most in the automobile industry think self-driving vehicles will be on the road by 2020 or earlier.

    Driverless cars will first be huddled with human-driven cars. But the first places where they will become dominant（统治的）are highly populated urban areas. Many advanced cities are already reducing the role of human-driven cars. Driverless cars will quicken that process and will bring us enormous benefits.

    Driverless cars will reduce accidents by around 90 percent. That's big—the annual deaths on the world's roads are about 1.2 million a year. Pollution and carbon emissions will drop, because urban driverless cars will be electric.

    On the other hand, driverless cars will cause problems. Over the next 20 years, the mostly low-skilled men who now drive trucks, taxis and buses will see their jobs reduced. Traditional carmakers are especially scared. The cars of the future might be made by tech companies such as Apple, Baidu and Google. Imagine Germany, where automobile making is the largest industry.

    Dramatic changes are coming, and driverless cars could arrive by 2020. But governments have barely begun thinking about it. Only 6 percent of the biggest US cities have taken them into their long-term planning. A decade ago anyone hardly saw the Smartphone coming. Now what about the driverless cars?

    Sometimes you'll hear people say that you can't love others until you love yourself. Sometimes you'll hear people say that you can't expect someone else to love you until you love yourself. Either way, you've got to love yourself first and this can be tricky. Sure we all know that we're the apple of our parents' eyes, and that our Grandmas think we're great talents and our Uncle Roberts think that we will go to the Olympics. But sometimes it's a lot harder to think such nice thoughts about ourselves. If you find that believing in yourself is a challenge, it is time you should build a positive self-image and learn to love yourself.

    Self-image is your own mind's picture of yourself. This image includes the way you look, the way you act, the way you talk and the way you think. Interestingly, our self-images are often quite different from the images others hold about US. Unfortunately, most of these images are more negative than they should be. Thus changing the way you think about yourself is the key to changing your self-image and your whole world.

    The best way to defeat a passive self-image is to step back and decide to stress your successes. That is, make a list if you need to, but write down all of the great things you do every day. Don't allow doubts to occur in it.

    It very well might be that you are experiencing a negative self-image because you can't move past one flaw or weakness that you see about yourself. Well, roll up your sleeves and make a change of it as your primary task. If you think you're silly because you aren't good at math, find a tutor. If you think you're weak because you can't run a mile, get to the track and practice. If you think you're dull because you don't wear the latest trends, buy a few new clothes. But remember, just because you think it doesn't mean it's true.

    The best way to get rid of a negative self-image is to realize that your image is far from objective, and to actively convince yourself of your positive qualities. Changing the way you think and working on those you need to improve will go a long way towards promoting a positive self-image. When you can pat (拍) yourself on the back, you'll know you're well on your way. Good luck!

    People like to post their selfies(自拍照) on social media. To know more about it, scientists at Syracuse University in New York recently did a research and came up with some surprising findings.

    People who post selfies and use editing software to make themselves look better show behavior connected to narcissism(自恋), the researchers said. Makana Chock, a professor from Syracuse University, said because social media is mostly used by people to share unimportant information about their lives, it is a good place for people to "work towards satisfying their own vanity." Those "likes" under their Facebook selfies make them feel good.

    Besides, people who post group selfies show a need for popularity and a need to belong to a group, the research found. Some people feel "peer(同伴) pressure" to post selfies and some follow the popular belief that if there is no picture of an event or experience, it did not really happen. "Anyway, it shouldn't be seen as negative. People get sense of satisfaction especially when they get likes. And it does no harm," Chock said.

    Other findings from the study include: There are no major differences on how often men and women post selfies and how often they use editing software. But men who post selfies showed more of a need to be seen as popular than women who posted selfies.

Chock said posting selfies on social media is not all that different from what people have done for many years. On trips and special events, our parents and grandparents used cameras instead of phones to take photos. They would bring back photos to show friends and family. You had no choice but to look at them. You probably commented about how nice everyone in the photos looked, especially children and the person showing the photos. They were happy to hear your comments. That was the old way of "clicking like". On social media, however, people can decide not to look at photos — even if they click "like".