New mercury(汞) threat to oceans from climate change

    Rising temperatures could boost mercury levels in fish by up to seven times the current rates, said Swedish researchers in an article published in Science Journal. They've discovered warming increases levels of the toxin (毒素) in sea creatures. In experiments, they found that extra rainfall drives up the amount of organic material flowing into the seas. This alters the food chain, adding another layer of complex organisms which boosts the concentrations of mercury up the line.

    Mercury is one of the world's most toxic metals, and according to the World Health Organization, is one of the top ten threats to public health. The substance at high levels has been linked to damage to the nervous system, paralysis and mental impairment in children.

    The most common form of exposure to mercury is by eating fish containing methylmercury(甲基水银), an organic form of the chemical which forms when bacteria react with mercury in water, soil or plants. Levels of mercury in the world's ecosystems have increased by between 200% and 500%, since the industrial revolution say experts, driven up by the use of fossil fuels such as coal.

    In recent years there have been concentrated efforts to limit the amount of mercury entering the environment, with an international treaty, called the Minamata Convention, signed by 136 countries in place since 2013.

Researchers hope that the Minamata treaty will be successful and countries reduce the amount of mercury that is being produced. Otherwise this discovery of a previously unknown source could have impacts for human health.

    Other researchers in the field say that the new study highlights important issues that have previously been little known.

     “This work experimentally proves that climate change will have a significant effect of methylmercury budgets in coastal waters and its accumulation in fish,” said Milena Horvat from the Jozef Stefan Institute in Slovenia.

     “This work will also help us understand the formation of mercury in fish and help reduce mercury from emission sources (primarily industrial).”

阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    Heroes of Our Time

    A good heart

    Dikembe Mutombo grew up in Africa among great poverty and disease. He came to Georgetown University on a scholarship to study medicine — but Coach (教练) John Thompson got a look at Dikembe and had a different idea. Dikembe became a star in the NBA, and a citizen of the United States. But he never forgot the land of his birth, or the duty to share his fortune with others. He built a new hospital in his old hometown in the Congo. A friend has said of this good-hearted man: “Mutombo believes that God has given him this chance to do great things.”

    Success and kindness

    After her daughter was born, Julie Aigner-Clark searched for ways to share her love of music and art with her child. So she borrowed some equipment, and began filming children's videos in her own house. The Baby Einstein Company was born, and in just five years her business grew to more than $20 million in sales. And she is using her success to help others — producing child safety videos with John Walsh of the National Center for Missing and Exploited Children. Julie says of her new program: “I believe it's the most important thing that I have ever done. I believe that children have the right to live in a world that is safe.”

    Bravery and courage

    A few weeks ago, Wesley Autrey was waiting at a Harlem subway station with his two little girls when he saw a man fall into the path of a train. With seconds to act, Wesley jumped onto the tracks, pulled the man into the space between the rails, and held him as the train passed right above their heads. He insists he's not a hero. He says: “We have got to show each other some love.”

Live in Cave

    Kokopelli's Cave Bed &Breakfast, Farmington, New Mexico.

    The idea may seem very stone age, but this lone unit, which was carved into a 65-million-year-old sandstone rock, is filled with modern amenities(便利设施). The Travel Channel says these “cave comforts” include a comfortable bedroom, large fire circle, and rainfall shower. Plus, the views of the La Plata River and nearby mountains are breathtaking.

    $260/ night; bbonline.com

    Sleep below the Surface

    Jules' Undersea Lodge, Key Largo, Florida.

    This hotel, which is named after20,000 Leagues Under the Sea author Jules Verne, is the world's only underwater hotel. Lonely Planet says that this former research station has been turned into a pleasant hotel. Guests must make the 21-foot dive to its two rooms, fully stocked kitchen, and showers. Don't want to cook? The staff will dive and bring your food to you.

    $400/night; jul.com

    Sail into History

    The Queen Mary, Long Beach, California

    Wish you could experience the greatness of a ship like the Titanic? According to CNN Travel, here's your chance. Book a room to get a taste of a bygone time on this ship-turned hotel. You may not be able to sail into the sunset like Kate and Leo, but you can enjoy onboard attractions like original 1930s artwork and tours of strange and mysterious hot spots.

    $129/night;queenmary.com

    As any plane passenger will confirm, a crying baby is almost impossible to ignore, no matter how hard you try. Now scientists believe they may have worked out why. A baby's cry pulls at the heartstrings(扣人心弦) in a way while other cries don't, researchers found.

    Researchers found that a baby's cry can trigger unique emotional responses in the brain, making it impossible for us to ignore them—whether we are parents or not. Other types of cries, including calls of animals in great pain, fail to get the same response—suggesting the brain is programmed to respond specifically to a baby' cry.

    A team of Oxford University scientists scanned the brains of 28 men and women as they listened to a variety of calls and cries. After 100 milliseconds—roughly the time to blink(眨眼)—two parts of the brain that respond to emotion lit up. Their response to a baby's cry was particularly strong. The response was seen in both men and women—even if they had no children.

    Researcher Dr Christine Parsons said, “You might read that men should just notice a baby and step over it and not see it, but it's not true. There is a special processing in men and women, which makes sense from an evolutionary view that both men and women would be responding to these cries.” The study was in people who were not parents, yet they are all responding at 100ms to these particular cries, so this might be a fundamental response present in all of us regardless of parental status.

    Fellow researcher Katie Young said it may take a bit longer for someone to recognize their own child's cries because they need to do more “fine-grained analysis”. The team had previously found that our reactions speed up when we hear a baby crying. Adults performed better on computer games when they heard the sound of a baby crying than after they heard recordings of adults crying.

    People say that text messages and e-mails lack emotion compared to phone or face-to-face conversations. But one thing seems to improve it – the emoticon(表情符).

    These little symbols – whether it's a wink(眨眼); -), a smiley : -) or a sad face : -) - always add a little something to whatever you are sending out, making it more expressive than cold words on a screen.

    To be sure, emoticons have changed the way that we communicate with each other. But there is more: a new study found that they are even changing how our brains work – we now react to emoticons in the same way as we would to real human faces, reported Live Science.

    It's actually amazing when you start to think about it: what an emoticon consists of is simply three punctuation marks(标点符号) – on their own, they carry no meaning as a pair of eyes, a nose or a mouth, but after they were first put together as symbols for faces in 1982, they began to appear more and more in our written materials.

    Owen Churches, a scientist at Flinders University in Australia, wanted to find out what people see in emoticons that make them so popular. So he showed 20 participants images of real faces, a smiley emoticon and a series of meaningless characters while their brain activities were monitored.

    Previous studies have already shown that our brains process human faces differently than they do other objects – they analyze the position of the mouth relative to the nose and the eyes to “read” for emotions. As a result, certain parts of our brain, such as the occipital-temporal cortex, are activated(激活).

    When Churches compared participants' brain activities, he was surprised to find that the brain areas that were activated when people looked at smiley emoticons were the same as when they were shown pictures of real faces.

    According to Churches, this is a good example of how culture is shaping our brains. “Emoticons are a new form of language that we're producing,” Churches told ABC Science. “Before 1982 there would be no reason that ':-)' would activate face-sensitive areas of the cortex, but now it does because we've learnt that this represents a face.”

    Next time you chat with your friends online, try to use emoticons where they are needed. It'll be almost like you're smiling or winking at them yourself.