原标题: 福建泉州中心医院生孩子价格365网

Science and technology科学技术How dung beetles navigate蜣螂如何导航Stars in their eyes眼里有星辰An insect that steers by the Milky Way观天识途的昆虫THE number of animals that navigate by the stars is small.靠观察星辰行走的动物不多。Only some birds, a few seals and, of course, humans have the ability.仅仅有某些鸟类、海豹,当然人也有这个本事。It had been assumed that other creatures that might do this would need reasonably well-developed brains.过去人们设想其他具备这种能力的生物很可能拥有发达的大脑。That notion has now been proved wrong as the celestial-navigation club welcomes its latest member: the humble dung beetle.现在这种见解被推翻了,因为天文导航俱乐部迎来了自己最新的成员—不起眼的蜣螂。Life in the world of dung beetles is fiercely competitive.蜣螂在这个世界上过着你争我夺的生活。After rolling up a ball of highly nutritious dung, the beetle must race off with it or risk having the ball stolen by other beetles.蜣螂必须把自己团好的极富营养的粪球搬走,否则劳动成果会被其他的蜣螂偷走。Strength is important, but so too is the route taken.力量很重要,运输路线也不能轻视。The ideal tactic on the open plains where many dung beetles live is to move in a straight line.很多生活在广阔平原上的蜣螂采用走直路的理想策略。This is easy enough during the day, but at night—when the beetles are most active—it is more challenging.这在白天不难办到,然而晚上才是蜣螂最活跃的时间,此时走直路对它们来说就是挑战了。Previous work has shown that dung beetles can make use of the moon to help them navigate, yet some still set a straight course on moonless nights.以前人们发现蜣螂利用月亮导航,如果晚上没有月亮,也有蜣螂走直路。To find out how, a team working in South Africa led by Eric Warrant and Marie Dacke, of Lund University in Sweden, designed an intriguing experiment.为了找到蜣螂夜里能走直路的原因,Eric Warrant和Marie Dacke领导的瑞典隆德大学工作团在南非设计了一个有意思的试验。They made caps for 19 dung beetles.他们给19只蜣螂做了帽子。Ten wore caps made of cardboard to prevent them seeing the sky and, as a control, nine wore caps made of transparent plastic.10只蜣螂戴着薄纸板做的帽子,这样他们就看不到天空了。作为对比,其他9只蜣螂戴上了透明塑料制成的帽子。The beetles and their dung balls were then released in the centre of a circular arena made of flattened sand and enclosed by a featureless circular wall.这些蜣螂和它们的粪球都被放在了一个平铺着沙子圆形场地的中央,场地的围墙也没有什么特别之处。As the beetles rolled away under a moonless night sky they were filmed by infra-red cameras.在没有月亮的晚上,红外线摄影机记录蜣螂搬运粪球的活动。The team found that the beetles prevented from seeing the sky by their caps had path lengths that averaged 476.7cm, much longer than the average of 143.4cm travelled by the beetles wearing clear hats.试验人员发现被帽子遮挡了天空的蜣螂平均行走476.7cm,远远超出戴着透明帽子的蜣螂的平均路程143.4cm。As the beetles might have used other overhead landmarks, like trees,因为蜣螂可能使用位于高处的其他地标。a second arena was built with a high black wall and a small, dry moat around it.第二个场地是黑色高墙围起来的,This time the beetles—minus their hats—were timed to see how long it took them to roll their balls from the centre to the point where they could be heard falling into the moat.附近有一条干涸的壕沟—这次蜣螂没有戴帽子—实验人员要看看他们从场地中央滚粪球到跌入壕沟能用时多久。Under a full moon the beetles took an average of 21.4 seconds to reach the moat.满月之夜蜣螂抵达壕沟平均耗时21.4秒。On a moonless, starry night, their speed was somewhat reduced, but not significantly so.在繁星满天的无月之夜,它们的速度有所下降,但降得不多。However, under overcast conditions, when neither moonlight nor the stars were visible, the beetles took an average of 117.4 seconds.如果晚上阴天,看不到星星和月亮,蜣螂抵达目的地要平均耗时117.4秒。Curious as to what it was in the sky that the beetles were using to navigate, the team moved their arena inside the Johannesburg planetarium and reran their experiments.因为试验人员急于了解蜣螂到底利用天上的什么物体导航,他们到约翰内斯堡天文馆做室内实验。As they report in Current Biology, the beetles presented with a full starlit sky, including the Milky Way or just the Milky Way, took statistically the same amount of time to exit the arena.他们在《当代生物学》杂志上统计了蜣螂在繁星满天的夜空下走出场地用的时间在统计学上是相同的,Under a sky full of dim stars they were only a little slower.天上的星光不亮,它们要稍微慢一点。This, speculates Dr Warrant, is because they were still able to spot the cluster that forms the Milky Way.通过试验Warrant,士推测,这是因为蜣螂还能认出系形成的星团。When allowed to see only the 18 brightest stars or immersed in total darkness, the beetles took more than twice as long to exit the arena.如果暗夜里只有18颗最亮的星星,蜣螂离开场地的时间要高出两倍以上。The team now wonders how many other animals might be able to use the glowing strip of light created by the Milky Way to guide them.这个团队的工作人员现在想知道到底有多少动物可以利用系形成的发光带活动。 /201310/261132

How the world sees America世界如何看待美国?Still on a hill依然在巅峰The NSAs snooping has done less damage than previously thought美国国家安全局的窥探造成的破坏比预想的要小VOTERS, journalists and just about everyone paying attention to politics all tend to overestimate the power of the president. When Barack Obama won the White House in 2008, many Americans were dazzled by his promises of change at home and a more judicious mix of strength and humility abroad. Indeed, it was hoped that Mr Obama would rescue Americas image after eight years of George Bushs brand of cowboy-booted diplomacy. Since then, Americas worries about how the world sees the president, and by extension the country, have divided between those who think he is aloof and reluctant to use military force, which makes America look weak, and those who think his administration intervenes too much, making the country seem callous.选民、记者以及关注政治的民众貌似都高估了总统的权力。当奥巴马总统2008年竞选成功入主白宫时,众多的美国民众被其国内改革和判断准确的实力与谦虚并重的国外政策弄得眼花缭乱。确实,在经历了布什总统8年的牛仔外交之后,人们希望奥巴马能够拯救美国的国家形象。自此以后,美国民众对世界如何看待美国总统及其怎样让国家富强的担忧已经分为两大阵营。一些人认为他不愿意使用军事力量,这让美国看起来十分懦弱,另一些民众则认为他干涉过多,让这个国家看起来很不近人情。This seems to have passed the rest of the world by, according to a Pew Research Centre world poll, published on July 14th. Foreigners do not much like being snooped on, and most countries disapprove of Americas use of drones. Yet most places outside the Middle East still view America favourably. Nor does Americas disenchantment with its president, whose job approval numbers hover around 40%, seem to be echoed elsewhere. Taking Pews numbers on whether countries expect Mr Obama to do the right thing in world affairs and comparing them with state-by-state presidential approval numbers from Gallup, it turns out that the 44th president is more popular in China than in all but three of the 50 states: Maryland, Massachusetts and Hawaii.根据皮尤调查研究中心7月14日发布的国际民意思调查报告,这种观点似乎不为外界所知。外国人不是很喜欢被窥视,许多国家都反对美国使用无人机。然而在中东以外的许多地区人们依然很喜欢美国。美国民众并没有对其总统失去信心、不抱幻想。总统的工作得到40%的民众的持,这也在其他方面得到回应。Mr Obamas popularity in China could come in handy. The most alarming finding in the study is that 62% of those polled in China worry that its border disputes will lead to armed conflict. Some 67% of Americans say the same thing. The presidents approval ratings did drop considerably in the two countries most affronted by the NSA: Brazil and Germany. Yet these opinions should be placed in context. Brazilians have long harboured suspicions of America. The countrys president, Dilma Rousseff, was once tortured for her opposition to a military government that most people on the Brazilian left believe was supported by America; the government that did the torturing fretted that Yankees might come and grab the Amazon.奥巴马在中国的欢迎程度极易可得。最令人警醒的结果是调查中,接受调查的中国人里约62%的人担心边界争端将会导致武装冲突。约67%的美国人也表达了同样的看法。总统的持率在被美国国家安全局公然侮辱的两个国家(巴西和德国)骤降。然而这些观点必须放在特定的语境中审视。长期以来,巴西人就对美国持怀疑态度。巴西总统迪尔玛·卢瑟福曾经因为她反对军事政府而遭折磨,而绝大多数的巴西左派人士认为这一军事政府是美国持的。实施折磨的政府担心美国人可能会入侵并攫取亚马孙地区。Meanwhile Germanys internal history with snooping has left the country wary of all government surveillance. And even Germans view America more favourably now than they did when Mr Bush was in charge. The one place where Obamas America is much less popular than Mr Bushs is Russia, a fact likely to be passed over when Republicans discuss how Mr Obamas weakness has emboldened Vladimir Putin.与此同时,德国窥探的内部历史使这个国家堤防所有形式的政府监视。现在,甚至连德国,相较于布什主政时期,对美国的态度更为友善。唯一一个让奥巴马通知下的美国不如布什时代受欢迎的国家是俄罗斯,这是共和党人讨论奥巴马的羸弱怎样给普金壮胆很可能会忽视的一个环节。Unfortunately what Pews numbers also suggest is that being well regarded does not count for much. Mr Obamas presence in the White House has improved Americas image abroad, but that has not helped to bring trade pacts, peace in the Middle East, a worldwide deal to cut carbon-dioxide emissions or any of the other things Mr Obamas boosters once thought he could achieve. Like most presidents, Mr Obama has so far had a foreign policy that consists of making unpleasant and unsatisfactory choices when faced with crises, rather than reshaping the world.然而不幸的是,皮尤调查中心的数据同时还表明被友好地对待并不能说明太多问题。奥巴马入主白宫确实提升了美国在国外的国家形象,但是这并没有帮助带来贸易协定、中东地区的和平、全球范围的二氧化碳减排协议抑或是其他奥巴马总统的持者曾经认为他所能带来的变化。正如许多其他的总统一样,目前为止,奥巴马总统在面对危机的时候,他所倡导的外交政策是做一些令人不愉快不满意的选择而非重整整个世界的秩序。 /201407/315756Don, why are you slouching?唐,为啥你无精打采?Dont you know its bad for you?你不知道这对你不好?Did you know that about 200 tons of debris strike the Earth every day?你知道每天大约200吨的碎片来到地球?So I was thinking!所以我在思考。Although most of this stuff burns up in the atmosphere, the resulting dust still settles and adds tothe Earths mass.虽然这些东西中的大部分在大气中烧掉了,但是烧完后的灰尘仍然沉淀并增添地球的质量。Thats about half a million tons per year!大约每年有50万吨。All right, but what does all this have to do with your posture?好的,但是所有这些与你的仪态有啥关系呢?So if the earth keeps accumulating mass, doesnt that mean that the Earths gravitational pull hasbeen increasing?所以如果地球持续累积其质量,那不是意味着地球的引力也正在增加?After all, gravity is directly proportional to mass.毕竟,引力与质量是成比例的。Are you saying you cant sit up straight because gravity is stronger now than it used to be?你说你不能笔直端坐是因为地球引力比以前更强了?Admit it, Yael;l–its a good one.承认这一点吧,这是件好事。Earths mass in metric tons is approximately six followed by twenty-one zeroes.地球的质量按照公制吨位来衡量大约是6后面加21个0。So assuming thatyour estimate is correct, and the Earth accumulates a half a million tons of debris every year.所以假设你的估计是正确的,并且每年地球积累50万吨的碎片。This means that in the sixty million years since dinosaurs existed the Earth would have accumulatedapproximately thirty trillion tons of meteoric debris.这意味着自从恐龙存在以来的6000万年,地球已经积累了大约30万亿吨的流星碎片。Thats thirteen zeroes.那是13个0。The point is that a number with thirteen zeroes is minuscule relative to a number with twenty-four zeroes.关键是13个零相对24个零而言是非常小的。While thirty trillion tons sounds impressive, it is nothing compared to the Earths total mass.虽然30万亿吨听起来很震撼,但是它与地球总的质量相比还是微不足道的。So it s definitely not all that extra gravity thats making you slouch所以很明确的是额外的重力不会使得你无精打采。 201408/321643

By the mid 1800s, the horse and the cowboy had come to symbolize the wild west. And of course, with the cowboys came cattle. As the bison quickly vanished from the landscape, cattle filled their place. 到19世纪中叶,马与牛仔成为了辽阔西部的象征。当然,既然提到牛仔,那么一定会提到牛。随着北美野牛快速地从大陆上消失,家牛取代了他们的位置。Meanwhile increasing numbers of the tame horses escaped into the wild. These feral horses became known by the Spanish name, mustang. They put extra pressure on the dwindling bison numbers by competing for their grazing sites and drinking holes. 与此同时,越来越多的被驯的马儿逃到了西部。这些野马成为了西班牙语中所称的“木斯塘马(mustang)”,它们数量的上升也给北美野牛的存活增添不少压力,它们与北美野牛争抢草原和水源。Mustangs form social groups led by a dominant stallion, echoing their prehistoric relatives that lived here during the Ice Age. 木斯塘马是一个群居的种族,由一匹占统治地位的公马领导整个族群,这一点和它们冰河时代栖息于此的史前亲戚相同。Bred to carry the weight of a rider, mustangs are larger than those early wild horses, but they still display the same kind of behavior. 木斯塘马是供人骑乘的,从体重看,他们比那些之前的野马体型更大,但是两种马匹的行为有很多相同之处。By the early 1800s, the wild horse was well and truly back in North America, but how did other wildlife on the continent survive alongside growing human populations?19世纪早期,野马真正回归北美大陆,但是大陆上其他的野外生物是怎么在人类数量速度增加的情况下存活的呢?Some wild creatures did the reverse of mustangs by becoming tame and choosing to live close to people. The purple martin became an unofficial mascot for native inhabitants in the eastern half of the continent. Here people erected special nesting sites to encourage the birds to stay.一些野外生物也和木斯塘马一样选择了追随人类并被其驯。在大陆的东半侧,北美洲紫燕在当地居民眼中是一种吉祥物。在这里,人类为紫燕建巢并希望这些鸟儿留在这里。英文文本来自普特英语,译文属未经许可不得转载。201311/266549Scientists have suspected for many years that fish might giveoff a chemical signal to warn other fish about the presence of predators.多年来科学家们一直都在怀疑鱼会释放一种化学信号来警告其他鱼类捕食者的出现。When a fish in a schoolis injured,比如说,当鱼群中的一条鱼受到伤害时,for example, the rest of the school will panic and swim away in response.鱼群中的其它鱼将会感到恐慌并且四散游开。Scientists dubbed this unknown chemical “Schreckstoff,”科学家将这种未知的化学物质命名为“Schreckstoff”,or “scary stuff” in German,德语译为“令人恐惧的东西”。but theydidnt know what it was composed of until recently.但是直到最近他们才知道这种物质的组成。A major component in fish skin, chondroitin sulfate,鱼的表皮中有一种叫硫酸软骨素的主要成分,appears to be the mystery chemical.似乎就是那种神秘的化学物质。When afish is wounded,当有一条鱼受伤时,this substance is converted by enzymes into sugary molecules that are thenshed into the water.这种物质就会通过酶的作用转化成含糖分子释放到水中。Scientists tested one of those molecules, glycosaminoglycan chondroitin or G for short, onzebra fish.科学家们测试了用斑马鱼释放出来的分子中的其中一个,可称为葡糖胺聚糖硫酸软骨素或简称为G。They found that the sugary warning is detected by special crypt cells in the brainsscent processing olfactory bulb.他们发现这种含糖的警告可以被特殊的隐窝细胞检测到,而隐窝细胞存在于大脑处理气味的嗅球中。This region is directly connected with higher areas of the brainand could initiate a quick flight response in fish.这一区域和大脑更高级的区域相连,可以刺激鱼快速逃跑。Scientists have also found that closely-related species sometimes respond to each others warningsignals,科学家们还发现亲缘关系很近的物种有时也对彼此的警报信号有反应,but unrelated species do not.但是不同的物种就不会有反应。This suggests that there may be a variety of sugary-smellingmolecules,这告诉我们可能会有各种各样闻起来像糖一样的分子,with each species producing their own version.每个物种会产生它们自己的版本。Because the zebra fish brain is relatively simple,因为斑马鱼的大脑构造比较简单,this research is allowing scientists to investigate atthe cellular level what happens in the brain when an organism detects danger.这项研究让科学家们可以在细胞水平上研究当生物遇到危险时大脑的反应机制。It will allow them tosee how groups of neurons regulate behavior and emotional responses.也可以研究神经组织是如何控制行为和情感反应的。Fortunately, fear doesnt smell sweet for humans.幸运的是,人类的恐惧闻起来不像糖。We can enjoy all the apple pie, ice cream, candyand cookies that we want.我们可以尽情的吃我们想吃的苹果派,冰激凌,糖果和饼干。 201403/281872

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