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德宏州妇幼保健院治疗烤瓷牙牙齿治疗种植牙多少钱云南昆明柏德口腔医院纯钛烤瓷牙怎么样Until recently, when scientists studied changes in open-ocean ecosystems, they looked at changes in the bottom of the food chain that gradually make their way to the top, like foodshortages and shifts in the ocean environment.直到最近,当科学家们在研究远洋地区生态系统的变化时,他们观察了处于食物链最底层并且在慢慢上升的变化,比如说食物短缺、海洋环境的变化。A recent study,however, suggests that more attention needs to be given totop-down influences as well.然而,最近的一项调查显示,人们还应该更多的注意自上而下的影响。For example, over the past few decades, theres been a major collapse of the populations ofharbor seals, fur seals, sea lions, and sea otters living on the coasts of western Alaska.比方说,在过去的几十年里,生活在阿拉斯加西海岸的斑海豹、海、海狮和海獭数量极具下降。Now a newstudy suggests that all this destruction can be traced back to humans overfishing sperm andbaleen whales between 1946 and 1979.现在,一项新的调查显示,所有的这些毁坏都可以归咎于人类在1946年到1979年期间过度捕捞抹香鲸和须鲸。Killer whales, who live at the top of the ocean food chain, used to prey on sperm and baleenwhales.虎鲸是在海洋食物链的最高层,它习惯于捕食抹香鲸和须鲸。When these were no longer available, the killer whales were forced to fish farther down the food chain.当虎鲸不能再捕食它们的时候,它就被迫捕食处于更下一层的食物链。First they fed on seals, which were the easiest to catch and the most nutritionallyvaluable.她们先捕食的是最容易捕捉且最有营养价值的海豹。Then, when seals became rare, the killer whales turned to sea lions.接着,当海豹变得稀少后,虎鲸便转向了海狮。When the sea lionpopulation crashed, they started fishing sea otters.而又当海狮的数量变少后,虎鲸又开始猎杀海獭了。The domino effect reaches even farther.多米诺效应又继续延伸。Without sea otters keeping sea urchins in check, their population has exploded.没了海獭约束海胆,海胆的数量变得庞大起来。And theyvedestroyed the kelp forests, and with it, the kelp forest ecosystem in southwestern Alaska.并且破坏阿拉斯加啊西南部的海藻林生态系统。Animals switching food sources can have a very serious effect on the environment.动物间交换食物来源对环境有着很严重的影响。And thatwe humans, as the ultimate predators, need to give a lot of thought to the choices we make.而作为终极捕食者,人类需要好好思考一下他们所做的选择。They may affect the food web in unintended ways.这些选择可能会以人们所不知道的方式来影响食物网。 201405/301199香格里拉市德钦县维西傈僳族县镶牙去哪里医院好 When you hear the term, ;computer geek,; what image immediately pops into mind?当你听到 “电脑狂人”这个词,你马上想到的是什么?Is the geek in your minds eye a woman? Probably not. 在你眼里会马上浮现女性的影像吗?可能不会。Theres a reason the stereotype of the computer geek is almost always depicted as male.这是因为刻板的电脑狂人几乎是男人的代名词。Around the world, significantly more men than women work in computer science.在世界各地,在计算机科学领域的男性明显比女性多。Sociologists understand that the underrepresentation of women in the sciences and mathematics isnt simply a matter of women stinking at these subjects or lacking interest in them.社会科学家理解在科学和数学领域女性的稀缺不是简单的女性讨厌这些学科或缺乏兴趣。If women believe they arent talented in science and math or that these subjects dont hold interest for them, this is in part a result of the widely circulated belief that these subjects come more naturally to men.如果女性认为他们在理科方面没有天赋,或者对这些科目不感兴趣,这部分是由于广为流传的相信这些科目天生适合男性。Women are thought to be better suited to fields such as education and healthcare.女性则被认为更适合教育和医疗等领域。Women who dare choose a career in the sciences or in math are likely to experience prejudice from their male colleagues, as well as from the community at large.敢选择投身于科学或数学职业的女性有可能体验到来自于她们男同事以及从社区的偏见。Sociologists found it curious though that the degree to which women are underrepresented in computer science varies largely from one industrialized country to another.然而社会学家惊奇地发现,在何种程度上计算机科学的女性稀缺很大程度上从一个工业化国家到另一个是截然不同的。Women are much better represented in computer science in South Korea, Ireland, and Turkey than in the Czech Republic, Germany, or Belgium, for example.韩国,爱尔兰,土耳其的女性在计算机和数学领域比捷克,德国,或者比利时等国家有着更为优异的表现。Why the difference?区别究竟在哪里?What South Korea, Ireland, Turkey, and the ed States all have in common is that governmental education requirements insist that girls and boys alike complete a significant number of science and mathematics courses in order to graduate from high school.韩国,爱尔兰,土耳其和美国所有的共同点是,政府教育坚持要求女孩和男孩为了高中毕业都必须完成大量的科学和数学课程。As a result of such requirements, girls are able to judge from experience whether their interests and talents lie in science and math rather than letting gender stereotypes decide for them.由于这种需求,女孩能从经验来判断自己是否在科学和数学具有天资或者感兴趣,而不是让她们根据性别来判断。 201310/261931云南伯德医院治疗地包天隐形矫正怎么样好吗

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昆明市哪家医院种植牙价位最低Cuba and the outside world古巴及世界Rekindling old friendships旧友重拾Cuba is once again resorting to geopolitics to support a failing economy古巴再次诉诸地缘政治,以撑其低迷经济CARLITO, a wiry man with greying hair, sits under a palm tree in Mariel, a town on a bay 40km west of Havana, sipping rum and watching a container ship edge out towards the Caribean. He recalls seeing a flotilla of smaller boats leaving from this same spot in 1980, carrying thousands of opponents of the Castro regime to Florida in the “Mariel boatlift”.Carito满脸疲倦,头发花白,静坐在马里埃尔镇的一棵棕榈树下,这一海湾小镇距离哈瓦那40千米,他抿一口朗姆酒,目送着一只载着集装箱的货船起锚驶向加勒比海,1980年的回忆袭上心头,当时一组略小的船只同样从这里起航,满载着成百上千的卡斯特罗政权的反对者,偷偷从马里埃尔驶向弗罗里达,Those were politically charged times. Government trucks would come to his school to deliver eggs for him and his friends to throw at the people fleeing. About a decade and a half later, after the collapse of the Soviet Union in 1989 plunged Cubas economy into crisis, sources of protein were so scarce that Carlito recalled those wasted eggs with bitter regret. Some “Marielitos”, as those who fled are known, returned recently and Carlito was stunned at how prosperous they had become. “We used to call them traidores (traitors),” he chuckles. “Now we call them traedolares (bring dollars).”当时政治斗争风生水起,政府的卡车会装载着鸡蛋来到他的学校,供他和他的朋友扔向那些逃亡的人群,但15年后,苏联解体,将古巴的经济一举推向危机的深渊,连蛋白质也成了珍稀产品,一想到当年浪费的那些鸡蛋,Carlito无不扼腕叹息。近来,一些当年逃走的所谓Marielitos的人重回古巴,他们的富有让Carlito大跌眼镜,他打趣儿的说,当年我们损他们为卖国贼,现在则称他们是生财佬。Across the bay from where Carlito sits is a 900m container port, which was built with Brazilian money and inaugurated in January. There are plans to develop a special economic zone alongside it, modelled on the thriving export hubs, such as Shenzhen, that China developed from 1980 onwards. The port is part of a vision for Cuba that relies less on Cuban-American gusanos (worms) sending remittances to prop up the local economy, and more on an inflow of foreign investors.穿过Carlito静坐的海湾,一个造价9亿美元的集装箱港跃入眼帘,该港口以巴西货币为经费,1月投入使用,计划是在其周边建设特别经济区,以一些蒸蒸日上的出口中心如深圳——1980年后中国腾飞的城市为模板,这一港口是古巴减轻对古巴裔美国人依赖计划的一部分,不完全指望他们为当地经济发展投入经费着力引进更多的外来投资。But Carlito is keeping his excitement in check. Construction workers building the container terminal were paid a mere 250 pesos a month, he says, so the ramshackle town has yet to benefit from the development. None of the 23 firms who have sought licences to operate in the special economic zone has yet been granted one. Even Joaquín Infante, the 88-year-old vice-president of the slow-moving National Association of Cuban Economists and Accountants, urges speedier authorisation of investment. “We need to be more flexible and take more risks,” he says.但Carlito并未喜出望外而是坐而观望,他说,建造集装箱港口的工人的月薪仅为250比索,这相对于扶持起一个摇摇欲坠的城镇来说无异于杯水车薪,尽管已经有23所公司申请了特别经济区的经营执照,但无一成功。即使是在步履蹒跚的古巴经济学家和会计师协会,88岁的副会长也要求对投资尽快审批,他说“我们应更加灵活机动,不畏风险。”Despite reforms that have brought some big changes to Cuba in the form of private restaurants, bed-and-breakfasts and new co-operatives, the economy has virtually ground to a halt. In the first half of the year GDP grew by just 0.6%, leading the government to reduce its estimate for full-year growth to 1.4%. That is lower than the 2.7% annual average figure since Raúl Castro (pictured on the right, with Vladimir Putin) became president in 2008.虽然改革带来了很大的机遇,古巴迎来了一些私人餐馆,住宿早餐包揽的旅馆和新的企业,但其经济发展停滞不前,今年上半年古巴的GDP增长仅为0.6%,这促使政府将全年增长预期调低至1.4%,这比卡斯特罗自2008年上任以来的年均数据2.7%还要低。Investment is the root of the problem. In a report in July, two Cuban economists, Omar Everleny and Ricardo Torres, estimated that the growth in Cubas capital stock, such as machinery and buildings, fell to 7.8% of GDP last year, close to its level of 5.4% in 1993 when the economy was in serious trouble. From the 20th floor of the Habana Libre, a run-down hotel, not one crane can be seen on the skyline. “The economy is screwed,” says a Havana-based diplomat.问题的根源在于投资,在7月的一则报告中,两名古巴经济学家奥马尔和里卡多预测诸如在机械和建筑领域的股本下跌至占GDP的7.8%,与1993年该国经济正处泥潭中的水平基本持平,从哈瓦那棚户区的一家旅馆的20层楼上观望,目光所及的天际之下,无一架起重机,哈瓦那的一名外交人员说,放眼国家经济,只让人眉头紧锁Supporters of the regime argue that the reforms simply need more time. A profit-oriented reorganisation of state-owned behemoths, such as the sugar monopoly, could be promising; it is just that the bureaucrats who run them are slow to change. Critics, however, see a fundamental flaw in the reform model. Although it has sought to give some people more freedom in what they make and sell, the state keeps a stranglehold on the inputs they need for those businesses, such as seeds for growing crops, or sauces and spices for restaurants, or spare parts for taxis. It has cracked down on “mules” bringing in such goods on passenger planes from abroad.政权的持者说,改革不过是需要更多的时间,以盈利为导向重组例如制糖垄断的国企大亨前景甚好,只是运营的官僚机构老牛破车,然而,批评人士认为,改革方略中存在根本性漏洞,虽说国家给予了人们制作和销售的更多的自由,但却严格限制做生意所需原料的进口,如粮食种子,餐馆的调味汁和香料或出租车的备件,他也严厉打击用客机从国外偷运这些商品的人。Diplomats say such counter-measures will make it harder for Cuba to attract the 2.5 billion in annual foreign investment that the regime aims for. Some also reckon the financial squeeze on the island has tightened this year in the wake of the case against BNP Paribas, a French bank, for evading American sanctions on doing business with Cuba, among other places.外交人员称在这些打击措施下,古巴更难实现年外资吸收达25亿美元的目标,一些人估计,对抗法国BNP Paribas事件使得今年的财政困难雪上加霜,该事件是为了躲避美国对其他地区实施的与古巴通商的制裁。That is why Cuba-watchers have paid close attention to the visits of Russias president, Vladimir Putin, and Chinas leader, Xi Jinping, in recent weeks. Though both men offered few concrete investments in Cuba, they provide an opportunity for the Castro regime to start reducing its dependence on its closest ally, Venezuela, whose pro-Cuba government has been rocked by instability this year. Says Mr Infante: “We have to diversify and not depend on just one partner.” He hopes that means more Chinese and Russian investment in Mariel.因此,持观望态度的投资者对近几周俄罗斯总统普京和中国国家主席习近平的来访甚为关注,虽说两人提供的实际投资不过寥寥,但这至少给卡斯特罗政权提供机会,减少对他亲密战友委内瑞拉的依赖程度,但该国持古巴的政权今年也在动荡中下台,infante说,我们应建立多元伙伴关系而不是依靠单独一个,他希望马里埃尔港能迎来更多来自中国和俄罗斯的投资。One envoy says the regime also prefers such investments to Western capital because it sees neither China nor Russia as a “Trojan horse” working towards regime change. A Cuban economist sees uncanny parallels with the special terms offered to the Soviet Union in the cold war. “The mentality of the decision-makers is to talk to Russia, talk to China, and make them offers based on politics,” he says. “But this is the same mentality we had in the past…and it didnt do much for productivity.”一位使者称该政权也希望能给西部首都带来同样的投资,因为他认为俄罗斯和中国的投资都不是“特洛伊木马”,企图推动政权更替,一位古巴的经济学家称在冷战期间针对苏联的措辞与此如出一辙,不可思议,他说;“决策者希望与俄罗斯和中国实现交流,使他们基于政治因素作出投资,但这不过是老调重弹,鲜有成效。”Cubas courtship of Russia is particularly striking: a day after Malaysian Airlines flight MH17 was shot down, Fidel Castro publicly blamed Ukraines government. Such an overtly pro-Russian stance on Ukraine may hinder political negotiations that started this year between Cuba and the EU, diplomats say. It also makes it harder for Barack Obama to improve Americas relations with Cuba, let alone consider an end to the counter-productive 54-year-old embargo. Back in Mariel, Carlito wants good relations with everyone, especially America. “Luckily we Cubans have a lot of patience and patience is good,” he says. “Without it theres just frustration.”古巴对俄罗斯的巴结尤其让人嗔目结舌,马航飞机MH17击落一天后,卡斯特罗便公开谴责乌克兰政府,外交人员说,它在乌克兰问题上公开持俄罗斯的立场可能会影响今年他与欧盟的政治对话,此外,奥巴马会更不情愿改善两国关系,更别提结束长达54年的禁运,虽说其效果是适得其反。卡斯特罗希望马里埃尔能与所有国家建立友好关系,尤其是美国,他说,幸运的是我们古巴人民锲而不舍,否则便只有槁木死灰。 /201408/320721 昆明柏德口腔医院看牙齿美白的价格丽江市古城区永胜县华坪县氟斑牙多少钱



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