When children start kindergarten, evident gaps in science knowledge already exist between Whites and minorities and between youngsters from upper-income and low-income families. And they often deepen into significant achievement gaps by the end of eighth grade if they are not dealt with during elementary school.

    The findings suggest that, in order for the United States to maintain(维持) long-term scientific and economic competitiveness in the world, policymakers need to renew efforts to ensure access(n.使用或见到的机会，权利) to high-quality, early learning experiences in childcare settings, preschools and elementary schools.

    The researchers' study tracked 7,757 children from their start in kindergarten to the end of eighth grade. Researchers found that, among kindergarteners with low levels of general knowledge, 62 percent were struggling in science by the time they reached third grade and 54 percent were struggling in that subject in eighth grade. And general knowledge gaps between minorities and Whites were already large at the time when students began kindergarten.

    “Children growing up in low-income families typically experience comparatively fewer early opportunities to learn about the natural and social sciences,” the authors wrote. “Their parents often have lower educational levels and therefore less science knowledge themselves as well as fewer resources available to direct the children's academic growth. Children raised in poverty often attend poorly resourced schools that futher limit their academic opportunities.”

    Morgan said that, within families, parents who regularly talk and interact with toddlers(学步的儿童) can point out and explain physical, natural and social events occurring around them daily. This might help youngsters learn facts and concepts that will prepare them to take better advantage of science instruction they receive during elementary and middle school.

Wilderness

    “In wilderness(荒野) is the preservation of the world.” This is a famous saying from a writer regarded as one of the fathers of environmentalism. The frequency with which it is borrowed mirrors a heated debate on environmental protection: whether to place wilderness at the heart of what is to be preserved.  

     As John Sauven of Greenpeace UK points out, there is a strong appeal in images of the wild, the untouched; more than anything else, they speak of the nature that many people value most dearly. The urge to leave the subject of such images untouched is strong, and the danger exploitation(开发) brings to such landscapes(景观) is real. Some of these wildernesses also perform functions that humans need—the rainforests, for example, store carbon in vast quantities. To Mr.Sauven, these ”ecosystem services” far outweigh the gains from exploitation.

    Lee Lane, a visiting fellow at the Hudson Institute, takes the opposing view. He acknowledges that wildernesses do provide useful services, such as water conservation. But that is not, he argues, a reason to avoid all human presence, or indeed commercial and industrial exploitation. There are ever more people on the Earth, and they reasonably and rightfully want to have better lives, rather than merely struggle for survival. While the ways of using resources have improved, there is still a growing need for raw materials, and some wildernesses contain them in abundance. If they can be tapped without reducing the services those wildernesses provide, the argument goes, there is no further reason not to do so. Being untouched is not, in itself, a characteristic worth valuing above all others.

    I look forwards to seeing these views taken further, and to their being challenged by the other participants. One challenge that suggests itself to me is that both cases need to take on the question of spiritual value a little more directly. And there is a practical question as to whether wildernesses can be exploited without harm.

    This is a topic that calls for not only free expression of feelings, but also the guidance of reason. What position wilderness should enjoy in the preservation of the world obviously deserves much more serious thinking.

    New York's iconic, blue-green statue of liberty wasn't always green. When the statue was gifted to the US from France in 1885, she was actually a shiny copper color. A new video reveals the chemical reactions involving oxygen and even air pollution that led to her color change from copper to liberty green. The statue of liberty was a gift from France to the US as a way of commemorating the US's fight for independence, as well as their own aspiration for democracy.

    A video, published by the American Chemical Society, explains that the 305-foot (93 meter) statue was built over nine years in sections of copper skin on top of an iron skeleton.

    In her first few decades in the Big Apple, the statue slowly turned from that shiny copper color to a dull brown and the, finally, to the blue-green, or as they'd say back in France, 'verdigris' we see today,' said the video's narrator.

When it changed color, some officials suggested restoring her back to her original color, but after the public protested against this decision, she was left the way she is. The statue's color change was as a result of oxidation reactions between copper and the air. But it was more than one reaction - the color change is due to about 30 years worth of different reactions leading to a mixture of greenish minerals.

    Oxidation reactions happen when an atom loses an electron to another atom.

    In the case of the statue of liberty, her color change was bound to happen due to oxygen in the atmosphere that is 'hungry' for electrons. On top of this, elements of New York City's polluted air added to the color change too.

The first chemical reaction of the color change involved copper giving up electrons to electron-hungry oxygen in the atmosphere. This led to a mineral called cuprite - which is pinkish red.

    Then, cuprite loses even more electrons to oxygen, forming a new mineral（矿物质） called tenorite, which is blackish in color. The black color of tenorite explains why the statue got darker over time, forming a dark brown color.

    Then, further chemical reactions occurred when sulfur（硫） in the atmosphere reacts with oxygen to form sulfur dioxide. Sulfur comes from natural processes such as volcanic eruptions, but also from man-made emissions from boats, cars, airplanes and factories. When sulfur dioxide in the atmosphere reacts with water, it produces sulfuric acid. Sulfuric acid forms green minerals with copper oxides, so the sulfuric acid in the atmosphere made the state green over time.

    Added to that, chloride from the sea spray surrounding Ellis Island where the statue is located made the statue even greener.

    The statue stayed this way for over 100 years because the exposed copper is now oxidized and stable, but the statue wouldn't be the same anywhere else.

    As countless unmade beds and unfinished homework assignments prove, kids need rules. Yet how parents make demands can powerfully influence a child's social skills, psychologists at the University of Virginia recently found after the conclusion of a study investigating the transition from adolescence to adulthood.

    Initially 184 13-year-olds filled out multiple surveys, including one to assess how often their parents employed psychologically controlling strategies, such as inducing guilt or threatening to withdraw affection. The kids rated, for example, how typical it would be for Dad to suggest that “if I really cared for him, I would not do things that caused him to worry”or for Mom to become “less friendly when I did not see things her way.”

    The researchers followed up with the subjects at ages 18 and 21, asking the young adults to bring along a close friend and, later, a romantic partner if they had one. These pairs were asked to answer hypothetical (假设的) questions that were purposefully written to inspire a difference of opinion. “We wanted to see whether they could navigate a disagreement in a healthy way, ”says study leader Barbara Oudekerk, now at the U. S. Department of Justice's bureau of statistics.

    In the October issue of Child Development, Oudekerk and her colleagues report that the 13-year-olds who had highly controlling parents struggled in friendly disagreements at age 18. They had difficulty stating their opinions in a confident, reasoned manner in comparison to the kids without controlling parents. And when they did speak up, they often failed to express themselves in warm and productive ways.

    The researchers suspect that pushy parents ruin their child's ability to learn how to argue his or her own viewpoint in other relationships. Although parents do need to set boundaries, domineering strategies imply that any disagreement will damage the bond itself. Separate findings suggest that parents who explain the reasons behind their rules and turn disagreements into conversations leave youngsters better prepared for future arguments.

    The consequences of tense or domineering relationships appear to get worse with time. This study also found that social difficulties at 18 predicted even poorer communication abilities at age 21. Psychologist Shmuel Shulman of Bar-Ilan University in Israel, who did not participate in the work, thinks these conclusions convincingly reveal how relationship patterns “carry forward” into new friendships.

Riding clubs

    You can start horse-riding at any age. Choose private or group lessons any weekday between 9 am and 8:30 pm (3:30 pm on Saturdays). There are 10 kilometres of tracks and paths for leisurely rides across farmland and open country. You will need a riding hat.

    Opening Hours: Monday through Friday: 9:00 am—8:30 pm

    Phone: (412)396—6754 Fax: (412)396—6752

Sailing Club

    Our Young Sailor's Course leads to the Stage 1 Sailing qualification. You'll learn how to sail safely and the course also covers sailing theory and first aid. Have fun with other course members afterwards in the clubroom. There are 10 weekly two—hour lessons (Tuesdays 6 pm—8 pm).

    Opening Hours: Tuesdays: 6:00 pm-8:00 pm

    Phone: (412)396—6644 Fax: (412)396—6644

Diving Centre

    Our experienced instructors offer one-month courses in deep-sea diving for beginners. There are two evening lessons a week, in which you learn to breathe underwater and use the equipment safely. You only need a swimming costume and towel. Reduced rates for couples.

    Opening Hours: Monday and Friday: 6:30 pm—8:30 pm

    Phone: (412)396—6312 Fax: (412)396—6706

Medical Center

    The staff of the Medical Center aim to provide convenient and comprehensive medical care to students and staff of the university. The center is well equipped and the staff here are trained to deal with a broad range of medical problems. Both female and male doctors as well as nursing staff are available for consultation. Also, all kinds of medicines are sold here and are cheaper for students than other drugstores.

    Opening Hours: 24 hour from Monday to Sunday

    Phone: (412)396—6649 Fax: (412)396—6648

Watersports Club

    We use a two-kilometre length of river for speedboat racing, and water-skiing. A beginners, course consists of ten 20-minute lessons. You will learn to handle boats safely and confidently, but must be able to swim. The club is in a convenient central position and is open daily from 9a.m to 4p.m, with lessons all through the day.

    Opening Hours: Monday through Friday: 9 am—4 pm

    Phone: (412)396—6899 Fax: (412)396—6890