We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1,000 years to decompose. Researchers have been unsuccessfully looking for a solution.

    The 16-year-old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute, has discovered a way to make plastic bags degrade(降解) in as few as 3 months, a finding that won him first prize at the Canada Wide Science Fair, a ＄10,000 prize, a ＄20,000 scholarship, and a chance to revolutionize a major environmental issue.

    Burd's strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms(微生物)．If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.

    With this goal in mind, he grounded plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth．Then he added the plastic powder and let the microbes work their magic for 3 months．Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control．Sure enough, the plastic exposed(暴露) to the live bacteria was 17% lighter than the control after six weeks.

    The inputs are cheap, maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.

    “Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me．One day, I got tired of it and I wanted to know what other people are doing with these plastic bags．The answer: not much．So I decided to do something myself.” Said Daniel Burd.

    Working with a group of baboons (狒狒）in the Namibian desert, Dr. Alecia Carter of the Department of Zoology，Cambridge University set baboons learning tasks involving a novel food and a familiar food hidden in a box. Some baboons were given the chance to watch another baboon who already knew how to solve the task, while others had to learn for themselves. To work out how brave or anxious the baboons were, Dr. Carter presented them either with a novel food or a threat in the form of a model of a poisonous snake.

    She found that personality had a major impact on learning. The braver baboons learnt, but the shy ones did not learn the task although they watched the baboon perform the task of finding the novel food just as long as the brave ones did. In effect, despite being made aware of what to do, they were still too shy to do what the experienced baboon did.

    The same held true for anxious baboons compared with calm ones. The anxious individuals learnt the task by observing others while those who were relaxed did not, even though they spent more time watching.

    This mismatch between collecting social information and using it shows that personality plays a key role in social learning in animals, something that has previously been ignored in studies on how animals learn to do things. The findings are significant because they suggest that animals may perform poorly in cognitive (认 知的）tasks not because they aren't clever enough to solve them，but because they are too shy or nervous to use the social information.

The findings may impact how we understand the formation of culture in societies through social learning. If some individuals are unable to get information from others because they don't associate with the knowledgeable individuals，or they are too shy to use the information once they have it，information may not travel between all group members, preventing the formation of a culture based on social learning.

    By now, you've probably been warned that a robot is coming for your job. But rather than repeat the warning, I've decided to throw down a challenge: man against machine.

    Start with the task we're doing right now: communicating in fluent human. We're sharing abstract ideas through words that we choose with an understanding of their slight difference and impact. We don't just speak in human; we speak as humans. A robot who says that science is fun is delivering a line (念一句话). A human who says that science is fun is telling you something important about being alive.

    Here's another inbuilt advantage we take for granted: as humans we are limited by design. We are bound in time: we die. We are bound in space: we can't be in more than one place at a time. That means when I speak to an audience, I am giving them something special. It's a custom-made, one-off, 100% robot-free delivery, from today's one-and-only Australian Chief Scientist.

    True, I now come in digital versions, through Twitter and Facebook and other platforms, but the availability of those tools hasn't stopped people from inviting me to speak in person. Digital Alan seems to increase the appetite for human Alan, just as Spotify (a digital music service) can increase the demand for a musician's live performances.

    Thanks to technology, many goods and services are cheaper, better and more accessible than ever before. We like our mass-produced bread, and our on-tap lectures and our automated FitBit advice. But automation hasn't killed the artisan bakery (面包店). Online courses haven't killed the booming, alongside their machine equivalents.

    Here's a third argument for the win. We humans have learned the habit of civilization. Let me explain this point by a story. A few years go, some researchers set out to study the way the people interact with robots. They sent out a small robot to patrol (巡逻) the local mall. That robot had a terrible time, and the villains of the story were children. They kicked him, bullied him, and smacked (掌击) him in the head.

    The point is not that the children were violent. The point is that the adults were not. They restrained whatever primitive impulse (冲动) they might have felt in childhood to smack something smaller and weaker in the head, because they had absorbed the habit of living together. We call it civilization. If we want artificial intelligence for the people, we'll need every bit of that civilizing instinct.

    Together, these points suggest to me that humanity has a powerful competitive edge. We can coexist with our increasingly capable machines and we can make space for the full breadth of human talents to flourish.

    The Boy Made It!

    One Sunday, Nicholas, a teenager, went skiing at Sugarloaf Mountain in Maine. In the early afternoon, when he was planning to go home, a fierce snowstorm swept into the area. Unable to see far, he accidentally turned off the path. Before he knew it, Nicholas was lost, all alone! He didn't have food, water, a phone, or other supplies. He was getting colder by the minute.

    Nicholas had no idea where he was. He tried not to panic. He thought about all the survival shows he had watched on TV. It was time to put the tips he had learned to use.

    He decided to stop skiing. There was a better chance of someone finding him if he stayed out. The first thing he did was to find shelter from the freezing wind and snow. If he didn't, his body temperature would get very low, which could quickly kill him.

    Using his skis, Nicholas built a snow cave. He gathered a huge mass of snow and dug out a hole in the middle. Then he piled branches on top of himself, like a blanket, to stay as warm as he could. By that evening, Nicholas was really hungry. He ate snow and drank water from a nearby stream so that his body wouldn't lose too much water. Not knowing how much longer he could last, Nicholas did the only thing he could—he huddled(蜷缩) in his cave and slept.

    The next day, Nicholas went out to look for help, but he couldn't find anyone. He followed his tracks and returned to the snow cave, because without shelter, he could die that night. On Tuesday, Nicholas went out to find help. He had walked for about a mile when a volunteer searcher found him. After two days stuck in the snow, Nicholas was saved.

    Nicholas might not have survived this snowstorm had it not been for TV. He had often watched Grylls' survival show. Man vs. Wild. That's where he learned the tips that saved his life. In each episode(一期节目)of Man vs. Wild, Grylls is abandoned in a wild area and has to find his way out.

    When Grylls heard about Nicholas' amazing deeds, he was super impressed that Nicholas had made it since he knew better than anyone how hard Nicholas had to work to stay alive.

    One day in the gym, I asked a coach, "What's the difference between the best athletes and everyone else?" He briefly mentioned the things that you might expect: genetics, luck, talent.

    But then he added something I wasn't expecting. "At some point," he said, "it comes down to who can handle the boredom of training every day and doing the same practice over and over again."

    Most of the time people talk about getting motivated to work on their goals. As a result, I think many people get depressed when they lose focus or motivation because they think that successful people never lack motivation that they seem to be missing. But that's exactly the opposite of what this coach was saying.

    When I was an athlete, I loved going to practice the week after a big win. Who wouldn't? Your coach is happy, your teammates are excited, and you feel like you can beat anyone. As an entrepreneur, I love working when customers are rolling in and things are going well. Getting results has a way of pushing you forward.

    But what about when you're bored? What about when the work isn't easy? What about when it feels like nobody is paying attention or you're not getting the results you want? It's the ability to work when work isn't easy that makes the difference.

    If you look at the people who are consistently achieving their goals, you start to realize that it's not the events or the results that make them different. It's their commitment to the process. They fall in love with the daily practice.

    So, fall in love with boredom. Fall in love with repetition and practice. Fall in love with the process of what you do and let the results take care of themselves.

    America is the world's largest food exporter. But the worst drought in half a century is hitting corn and wheat harvests. The drought across the central United States adds to concerns about world food supplies and prices in the coming years.

    Experts say by 2050, the world will have to produce at least sixty percent more food to feed a population growing bigger and bigger. China, a major food importer, is looking for producers around the world to guarantee future food supplies.

    China has invested in food production in Australia and New Zealand. A new source of supply is Ukraine. Ukraine was known as the breadbasket of Europe because of rich corn and wheat harvests a century ago.

    Galyna Kovtok is chief executive of Ukraine's largest agricultural business, ULF. She predicts that within a few months her company will be approved to export corn to China. That will make Ukraine the first country outside the Americas to do so.

    ULF will soon have almost two million tons of elevator storage capacity as it prepares for the Chinese market. Chinese money is financing the building of six grain elevators. But the company's equipment is largely American, including half-million-dollar John Deere combines to harvest wheat.

    ULF'S grain production per hectare (公顷) is now halfway between Ukrainian averages and the high yields of the American Midwest. But farming depends on the weather. Across the Black Sea region—in Ukraine, Russia and Kazakhstan--drought this year is pushing harvests down by fifteen to twenty percent.

    Traditionally, the Black Sea region is the main source of wheat for North Africa and the Middle East. But this year, on the supply side, Russia may have to stop exports. And, on the demand side, Africa and the Middle East are now competing with China.

    At the same time, a new report says large parts of Asia may face long periods of severe drought within ten years. It says northern China, India, Afghanistan, Mongolia and Pakistan will be especially hard hit. It says other parts of Asia are likely to face longer and wetter monsoon seasons (雨季) because of climate change.