Wherever she goes, Molly leaves her mark. Without saying a word, she speaks to people with her kind eyes. Even when she walks away, she leaves an impression. Molly's mark is a smile, stamped into the ground by the horseshoe at the bottom of her false leg．

    A few years ago, Molly was badly attacked by a dog. The dog bit all four of Molly's legs and left large cuts in her face. Molly's owner, Kate Harris, took her to an animal hospital. Doctors there were able to save Molly's life, but soon one of her legs became very infected (感染).

    At first, doctors thought Molly would have to be put to sleep. But Molly changed their minds. This pony, doctors noticed, shifted her weight, and rested her good leg from time to time. Doctors knew that Molly had amazing intelligence, and that she wanted to live.

    Several doctors operated on Molly, and removed her infected leg. A false leg was made for her. The leg was a hollow cast with a pole at the bottom for balance. Doctors gave Molly a special horseshoe at the bottom of the leg. This horseshoe she had had a stamp of a smile face in it!

    After the operation, Molly walked around on all four legs, as if nothing had ever happened to her! Now, with every step she takes, she stamps a smile in the dirt. But she leaves her mark in other ways, too.

    Kaye Harris took Molly to the false leg center. There were children there who, like Molly, had artificial arms or legs. They were amazed to see a pony with a false leg. Molly made them smile and gave them hope. Soon, Molly began to visit schools, nursing homes, army bases and hospitals. A book was even written about Molly!

    Women are friendly. They often share with others. But men are more competitive. They are trying to improve their social status. Why? Researchers have found it's all due to the hormone oxytocin (荷尔蒙催生素). Although known as the love hormone, it affects the sexes differently.

    Generally, people believe that the hormone oxytocin is let out in our body in various social situations and our body creates a large amount of it when falling in love or giving birth.

    But in a former experiment Professor Ryan found that the hormone is also let out in our body during a negative situation such as envy (嫉妒).

    Further researches showed that in men the hormone oxytocin improves the ability to recognize competitive relations, but in women it raises the ability to recognize friendship.

    Professor Ryan's recent experiment used 62 men and women aged 20 to 37.

    Half of the participants (参与者) received oxytocin. The other half received placebo (安慰剂).

    After a week, the two groups switched with participants. They went through the same steps with the other material.

    Following each treatment, they were shown some video pictures with different social behavior. Then they were asked to analyze the relations by answering some questions. The questions were about telling friendship from competition. And their answers should be based on gestures, body language and facial expressions.

    The results showed that, after treatment with oxytocin, men's ability to correctly recognize competitive relations improved, but in women it was the ability to correctly recognize friendship that got better.

    Professor Ryan thus concluded, “Our experiment proves that the hormone oxytocin can raise people's abilities to better tell apart different social behaviors.”

    Sharon, Aged 22

    The most important thing to keep in mind when going into high school is to be yourself. Besides, I don't know what your middle school was like, but high school teachers will not care about things such as how much homework you already have in one night. It's best to just learn to deal with things and manage your time wisely so you can achieve everything you need to.

    Frank, Aged 21

    I think almost every kid feels both nervous and excited before their first day. You will probably love it. I know I did. You should join some sports or activities that will make your high school experience more enjoyable.

    Good luck!

    Eddie, Aged 20

    When I started high school I was really nervous too, especially since I had been homeschooled all through middle school and didn't really know anyone. I suppose the best advice would be to just relax. The first couple of days can be a little bit hard, but things will become easier before you know it.

    David,  Aged 19

    I am not going to lie. The first day is kind of frightening. But you'll get used to it. Don't be afraid of anyone; upperclassmen will pick on you more if you let them know you're afraid. Just take it easy. Making some friends and staying with them will greatly help you get used to high school quickly. After the first week it's really not bad at all. Don't worry.

    Plastic waste has polluted the Arctic. Two new studies have spied bags, fishing rope and tinier bits of rubbish in the Barents Sea. This sea sits north of Norway, Sweden, Finland and Russia. It mixes with the Arctic Ocean, which is even farther north.

    Plastic waste in the Arctic could harm wildlife and may hint that large volumes of human rubbish are collecting there, says Melanie Bergmann. She is one of the scientists who spotted the waste. She studies Earth's oceans at the Alfred Wegener Institute in Bremerhaven, Germany. She first started counting bits of plastics in the Barents Sea because she kept spotting signs of the stuff there in images taken with deep-sea cameras.

    Bergmann and her colleagues counted pieces of plastic from an icebreaker, a boat designed to break through large blocks of ice in very cold waters. They also tracked plastic pieces they saw during helicopter rides over Arctic waters. The team found 31 pieces of plastic. “That doesn't seem like much, but it shows us that we've really got a problem, one that extends even to this remote area, far from civilization,” Bergmann says. She and her colleagues described their findings October 21 in Polar Biology.

    Another team has also been counting plastics in the area. Those scientists took water from the Barents Sea and counted the number of smaller bits of plastics, called microplastics.

    Plastic in the ocean is dangerous to animals. Some may get caught in rope or bags. And wildlife may swallow bags and other plastic bits. That makes them feel full. But some may eventually starve because they are not getting the nutrients they need to live. Sometimes plastics also may break down in an animal's body and release poisonous chemicals. If another animal later eats the one that swallowed plastic, it too can end up with poisonous chemicals in its body. This, in turn, can travel up the food web, endangering predators (肉食动物) — even people.

    When you're a parent to a young child, you spend a lot of time talking about feelings: about having to share, about being disappointed because you may not have a cookie instead of broccoli (绿花椰菜), about the great injustice of a parent pressing the elevator button before the child has a chance to.

    And in a parenting culture that's increasingly concerned with centering children's needs above all else, mothers and fathers have become skillful at talking about their kids' feelings while masking their own. But new research suggests that parents who hide their negative emotions are doing their children, and themselves harm.

    A study published this month says that when parents put on a faux­happy (假开心) face for their kids,  they do damage to their own sense of wellbeing and authenticity.

"For the average parent the findings suggest when they attempt to hide their negative emotion expression and overexpress their positive emotions with their children, it actually comes at a cost: doing so may lead parents to feel worse themselves," researcher Dr. Emily Impett, says.

    It makes sense that parents often fall back on amping up (扩大) the positivity for the sake of their children — there are a lot of things in the world we want to protect our kids from. But children are often smarter than we expect and are quite in tune with what the people closest to them — their parents — are feeling.

    There was a time about a year or so ago, for example, when I received some bad news over the phone; I was home with my four­year­old and so I did my best to put on a brave face.  She knew immediately something was wrong though, and was confused.

    When I finally let a few tears out and explained that Mom heard something sad about a friend, she was, of course, just fine. My daughter patted my shoulder, gave me a hug, and went back to playing. She felt better that she was able to help me, and the moment made a lot more sense to her emotionally than a smiling mom holding back sobs. I was glad that I could feel sad momentarily and not have to work hard to hide that.

    Relaying positive feelings to your children when you don't feel them is a move the researchers called high cost — that it may seem like the most beneficial to your child at the time but that parents should find other ways of communicating emotions that "allow them to feel true to themselves".

    But this is also about children seeing the world in a more honest way. While we will want to protect our children from things that aren't age­appropriate or harmful, it's better to raise a generation of kids who understand that moms and dads are people too.

    The number of snow geese arriving in the Arctic each spring to breed has risen over the past few decades. At first, wildlife biologists saw this as an environmental crisis, pointing to marshes（湿地） where plants were eaten by the hungry birds. In response, the federal government loosened restrictions on snow goose hunting.

    But how do the Inuit, in whose backyard this is taking place, view the situation? A recent plan is giving Inuit wildlife experts the opportunity to lend their knowledge to managing the species. The snow goose study, which is supported in part by Polar Knowledge Canada and led by the Kivalliq Wildlife Board (an Inuit organization that manages hunting, trapping and fishing in central Nunavut), asked the experts to share their generations of knowledge about snow geese and their views on what should be done.

    “The community had concerns about controlling the population,” says Ron, a community officer of the Kivalliq Inuit Association, “and Inuit snow goose knowledge had never been recorded. People wanted to pass on what they knew.” Inuit experts disagreed with that, considering it wasteful and unnecessary. They felt hunting more snow geese in an organized way, such as paying local hunters a minimal amount of money and distributing the birds to disadvantaged families or operating a limited commercial hunt by employing local people, would be appropriate.

    Inuit wildlife experts will plan to call on scientists this fall. They say they hope to search for a common way forward and that while there may be too many snow geese in some areas, it's not a crisis. Biologists now generally agree that there seem to be plenty of undamaged marshes available and newer research shows that some damaged areas can recover.

    “Now that we have recorded and documented Inuit knowledge of snow geese,” says Ron, “when facing the crisis other people will be able to use the information to help manage the species, which is fundamental to dealing with it effectively.”