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来源:泡泡新闻    发布时间:2018年04月20日 05:33:08    编辑:admin         

Science and technology科学技术Invasive species入侵物种Boom and bust繁衍与湮灭Invasive Argentine ants may be less persistent than once feared入侵性阿根廷蚂蚁可能没有想象的那么可怕Ready for take-off随时准备离开DESPITE their name, Argentine ants are a well-travelled lot.如果不顾它们的恶名,阿根廷蚂蚁可以说是很好的旅行家。Human commerce has allowed them to hitch rides from their homeland to every continent on the planet, with the exception of Antarctica.人类的商业活动将它们带到了世界各大洲,南极洲除外。And when they arrive, they often thrive.并且当它们到达时,它们就会繁衍。At least 15 countries now host colonies, which frequently prosper at the expense of native species.目前,至少15个国家受到外来物种的入侵,这种入侵是以牺牲本土物种为代价的。This flexibility, combined with an aggressive temperament, makes them one of the worlds best-known and most-hated invasive species.这种侵略性及适应性使得它们成为世界上最著名同时也是最令人深恶痛绝的入侵物种。Yet, as any general knows, establishing a beachhead is not the same thing as conducting a successful, long-term occupation.但是,众所周知,建立一个滩头阵地不同于成功地进行一次长期占领。Argentine-ant colonies sometimes collapse suddenly, and with no obvious explanation.阿根廷蚂蚁的入侵有时突然毫无缘由地停止。In a paper just published in Biology Letters, a group of researchers at Victoria University of Wellington, in New Zealand,在最近发表在《生物书简》上的一篇文章中,新西兰惠灵顿维多利亚大学的一组研究人员,led by Meghan Cooling and Phil Lester,由梅根?库灵和菲尔?莱斯特领导,describe their attempts to study such disappearances systematically.描述了他们对这种系统性消失的研究。The researchers examined 150 sites across the country where Argentine-ant nests had been recorded.研究者们考察了全国范围内150个已经被记录下来的阿根廷蚂蚁据点。At 40% of them they found that the ants had vanished.他们发现其中的40%已经消失,At many of the other sites, ant numbers were much reduced,而在其他的据点,蚂蚁数量减少,with areas that once sported dozens of nests over hundreds of hectares reduced to just one or two colonies covering much smaller tracts of land.原来几百公顷的面积上有几十个蚁巢,而现在一片小面积土地上只有一两个聚居群。And with the invaders gone, native ants seemed to be re-establishing themselves,随着侵略者离开,本土蚂蚁似乎在重建自己的种群,suggesting that the Argentine ants impact on biodiversity had been transient, rather than permanent.这表明阿根廷蚂蚁对生物多样性的影响只是暂时的。A statistical analysis of the data yielded an estimate for the likely survival time of a typical colony of between 12.9 and 15.3 years,数据统计分析估测了一个典型的聚居群可能的生存时间。and suggested that warm and dry conditions were more favourable for survival than cold, wet ones.该分析也表明,比起寒冷潮湿的条件,温暖干燥的环境更有利于生存。Exactly what caused the collapses is still not clear, although the researchers suspect that unfamiliar diseases may have played a role.尽管研究者们怀疑不熟悉的疾病可能起到了一定作用,但导致阿根廷蚂蚁消失的确切原因尚不清楚。y is not strength团结不是力量It is a plausible theory.这种理论可信。Because they grew from a small number of founder colonies,因为它们是从很小的群体发展起来的,or possibly even a single one,New Zealands Argentine ants are genetically similar to one another.新西兰的阿根廷蚂蚁之间的基因非常相似。That may be one reason for their success: ant researchers hypothesise that, being so closely related,这也许是它们成功的原因之一:蚂蚁研究者假定,the individual insects are unable to distinguish their nest mates from members of other colonies,关系紧密的个体昆虫不能够把同巢穴的同伴同其它聚居区的成员区分开来,which causes ants from different nests to co-operate as if they were kin,这导致来自不同巢穴的蚂蚁就像亲戚一样相互合作。and has led students of the field to speak not of hundreds of individual infestations, but of a single, country-spanning super-colony.这使得这一领域的学者不再谈及成百的个体侵扰,而是谈及单一的、跨越全国的超级群体。But a shallow gene pool can be a weakness, too.但是,一个浅薄的基因库也可能是一个弱点。If one nest proves susceptible to some environmental factor,如果一个巢穴容易受到某些环境因素的影响,be it disease, predation, or even a cold snap or wet spell,不管是疾病、掠食,亦或是寒流、潮湿期,then it is likely that all the other colonies will share that vulnerability.那么极可能其他的聚居群也有着同样的弱点。Now that they have documented the extent of the collapse the next step,库灵表示,他们现在已经记载了蚁群消失的范围,says Ms Cooling, is to test the hypothesis of genetic vulnerability and try to work out precisely what causes the sudden reversals of formicine fortune she has seen.下一步是验基因脆弱性这一假设,并努力找出导致蚁群突然转变的确切原因。And it is not just ecologists who will be waiting for the results.而等待这一结果的不止是生态学家。New Zealands government had reckoned it might have to spend NZm a year keeping the newcomers under control.新西兰政府估计,每年可能会花掉NZm用于控制新物种的入侵。If Mother Nature can do the job instead, then it would represent a tidy saving for the countrys exchequer.如果自然母亲能够完成这项工作,那将会为国库省下一大笔资金。 点击此处下载本期经济学人讲解PDF与音频字幕 /201306/244905。

Georgias history格鲁吉亚的历史Bad location糟糕的位置Despite its unhappy history and dire geography, Georgia is doing well虽然历史坎坷,位置糟糕,格鲁吉亚现在做得不错Edge of Empires: A History of Georgia. By Donald Rayfield.《帝国的边缘:格鲁吉亚的历史》。作者:Donald Rayfield。Georgia: A Political History since Independence.《格鲁吉亚:自独立开始的政治历史》。作者:Stephen Jones。TO MOST outsiders Georgian history is a closed book. Indeed for English-speakers there are practically no books at all. Georgia mostly features on the edges of other peoples histories. Xenophon, describing Greek mercenaries attempts to get home in 400, wrote the first description of it. Books about the Soviet Union highlight Georgias role as a rebellious captive and as the birthplace of Josef Stalin, its most infamous son. A flurry of recent accounts describe the brief, disastrous war with Russia in 2008. Now Donald Rayfield of the University of London and Stephen Jones of Mount Holyoke College in Massachusetts have written ambitious and comprehensive histories of a complex country.大多数非格鲁吉亚人对格鲁吉亚的历史一无所知。实际上基本没有一本关于格鲁吉亚历史的书籍是用英语写的。大多数情况下,格鲁吉亚只能在别国历史的边边角角里看到。公元前400年,描述希腊雇佣兵为回家而努力的色诺芬第一次提到了格鲁吉亚。关于苏联的史书将格鲁吉亚要么视为叛逆的俘虏,要么视为其最罪名昭著的国民约瑟夫·斯大林的诞生地。最近出版的一系列书描述了格鲁吉亚与俄罗斯在2008年展开的那场灾难性的短暂战争。现在,伦敦大学的Donald Rayfield和马萨诸塞州曼荷莲女子学院的Stephen Jones为读者描绘出这个复杂的国家恢弘而又全面的历史。The authors are among a handful of foreigners to have mastered Georgian. Part of the small and ancient Kartvelian language family, it is related to no others, though some have fancifully claimed a distant cousinhood with Basque. Its roots are as obscure as the origins of those who speak it. Mr Rayfield starts around 1100, with the first mention in an Assyrian source of the “Mushki”. The first Georgian king, Parnavaz, was born in 326.这两名作者是少数几个掌握格鲁吉亚语的外国人。尽管有些人异想天开地宣称格鲁吉亚语和巴斯克语许久之前同系一源,但其实格鲁吉亚语是卡特维利语族的一个古老的小分,和其他语言都不相关。格鲁吉亚语的起源和格鲁吉亚人的起源一样湮灭在历史的尘埃中。Rayfield从公元前1100年左右开始写起,亚叙的史书在那时第一次提到“Mushki”。第一个格鲁吉亚国王Parnavaz诞生于公元前326年。The scope of Georgian history may be a humbling shock for those who thought the country appeared on the map only when the Soviet Union collapsed in 1991. But the er needs to take a deep breath, for the next 200 pages could be mistaken at times for a stray appendix from J.R.R. Tolkiens “The Lord of the Rings”. The tersely told stories involve hundreds of unknown but like-sounding people and places which appear and disappear in quick succession. The beheadings, castrations, sodomisations, rapes and eye-gougings—a local speciality—that dot the pages are jolting. But a little more in the way of analogies, signposts, interpretation and characterisation would have lightened the mixture.对于那些认为格鲁吉亚在1991年苏联解体时才出现在地图上的人来说,格鲁吉亚历史的源远流长可能是个令人羞愧的发现。但是读者需要深呼吸一下,因为之后的200页有时候会被人误以为是J.R.R.托尔金所著的《指环王》丢失的附录。一个个用词简练的故事里有着成百上千个不知名却听起来都很像的人物和地点,这些名字快速地出现,又快速地消失。在这部分,不时出现的砍头、阉割、、强奸和挖眼情节让人看得触目惊心。如果多点类比、线索、解释和特征描述将会使这部分读起来不那么沉重。The most cheerful pages concern Georgias golden age—around 1212 at the height of Queen Tamars reign. The country has never since been bigger, stronger or safer, stretching 800 miles (1,288km) from what is now Trabzon in Turkey to the shores of the Caspian sea. Georgias fortunes depend on the weakness or goodwill of its much larger neighbours: Russia to the north, Persia to the south-east, Turkey to the west. Mr Rayfields powerful theme is of brief periods of prosperity and security, ended by invasion, conquest, looting and despoliation. Georgians have had to get used to rule by outsiders: they often outwit them. Kremlin rule began with mass murder and ruinous economic planning, but in later decades Georgia was one of the most prosperous and enjoyable places to live in the Soviet Union. It was a similar story in the 19th century under Russian imperial rule.在该书中,读起来最让人心情愉快的部分与格鲁吉亚的黄金时代有关—格鲁吉亚的黄金时代在1212年左右塔玛皇后执政时期达到顶峰。那时的格鲁吉亚的疆域最大、国力最强、局势最稳。其疆域绵延800英里(1288公里),从现在位于土耳其的特拉布宗一直到里海的海岸。只有在那些比格鲁吉亚大得多的邻国处于衰弱时期,或者对格鲁吉亚态度友好时,格鲁吉亚才得以繁荣。这些邻国有北部的俄罗斯,东南部的波斯以及西部的土耳其。在Rayfield宏大的著作中,格鲁吉亚每次短暂的繁荣和稳定后都是列强的侵略和肆意抢劫。格鲁吉亚人不得不习惯于被外国人统治:但他们常常比统治者更聪明。苏联占领格鲁吉亚初期展开大屠杀和毁灭性的计划经济,但在随后的几十年里格鲁吉亚是苏联最繁荣最适宜居住的地方。19世纪格鲁吉亚被俄国君王统治时也是相似的情形。Georgias rulers own penchant for internal divisions and double-dealing has played a big role in prompting the countrys many disasters. So too has the failure of faraway outside powers to reciprocate Georgias pro-Western sentiments. The story of the years 1918-21, when the Georgian Democratic Republic made repeated vain appeals to Britain and other Western powers, before the Bolsheviks invaded, make poignant ing. They echo previous episodes involving Georgian rulers entreaties to the Byzantine empire and Venice—and foretell, perhaps, the let-down that many Georgians felt when nobody came to their aid in 2008.格鲁吉亚的许多灾难都是因为该国统治者喜欢内部斗争和耍两面派造成的。遥远的外部力量没能回应格鲁吉亚亲西方的感情也是因为这些统治者。1918至1921年间,格鲁吉亚民主共和党一次又一次向英国和其他西方列强求助无果,最后被布尔什维克侵略,这个故事读起来让人辛酸。这与该书之前讲到的格鲁吉亚统治者向拜占庭帝王和求助的故事惊人地相似。这个故事也许还预示着2008年因为无人帮忙许多格鲁吉亚人会品尝到失望。Mr Jones deals at book-length with the years covered by Mr Rayfields final chapter. Georgias disastrous rebirth, amid economic collapse and civil war, gave way to a period of sleazy stagnation under Eduard Shevardnadze, who had run the place in Soviet times and then served as Mikhail Gorbachevs foreign minister.Jones的书涵盖的年份和Rayfield的书中最后一章相同。先是格鲁吉亚在经济崩溃和内战后充满灾难的重生,随后就是Eduard Shevardnadze领导下的经济停滞。Eduard Shevardnadze在苏联时期管理格鲁吉亚,后来成为米哈伊尔·戈尔巴乔夫执政时期苏联的外交部长。Amid much useful detail, Mr Jones snipes at the record of Mikheil Saakashvili, who became president after the “Rose Revolution” of 2003. His party narrowly lost the parliamentary election this year. To the surprise of those who saw Putinesque tendencies in his camps authoritarian approach, Mr Saakashvilis party has calmly conceded defeat.Jones的书提供了很多有用的细节。其中的一个是米哈伊尔·萨卡什维利的执政履历。萨卡什维利在2003年的“玫瑰革命”后成为总统。他所在的政党在今年的议会选举中惜败。然而令那些认为该党独裁的统治方式越来越接近普京时,萨卡什维利所在的政党平静地承认了失败。That came too late for either book, which is a pity because it would offset many of Mr Joness criticisms of Georgias failure to meet his perhaps rather unrealistic standards of “virtuous” democracy. Much of the country outside the capital, Tbilisi, is still dfully poor; institutions are imperfect; government pressure on the media and judiciary can be heavy-handed or even nastier. But for a place that was a failed state only 20 years ago the progress is startling, especially given the near- constant pressure, subversion and denigration from Russia.可惜他的竞选失利对于这两本书而言都来地太晚了。如果这发生地再早些,就能推翻Jones对格鲁吉亚没能达到他可能相当不实际的“高尚”民主标准的许多批评。首都第比利斯以外的许多地区仍然极度贫困;各类机构问题百出;政府对媒体和司法的压力很大,有时甚至会采用下流的手段。但对于一个20年前还被认为是“失败国家”的地方来说,特别是考虑到该国几乎一直受到俄罗斯的压迫、暗中破坏和抹黑,其进步还是非常惊人的。Mr Jones skates over the problems caused by Russia and underplays the real achievements of the Saakashvili years. These include bringing the country closer to the West, eliminating petty corruption, for example in the customs service and the traffic police, modernising public services, attracting foreign investment and establishing an open if rough-hewn political system. Georgia is now a country where the opposition has a real chance of winning power, and all sides abide by the constitution. Readers of Mr Rayfields book may feel that in the past 2,500 years Georgians have seldom had so much to be happy about.Jones一笔带过俄罗斯给格鲁吉亚造成的问题,轻描淡写萨卡什维利执政时期取得的成就。这些成就包括使该国与西方关系更紧密,消灭了诸如在海关和交警的基层腐败,使公共务现代化,吸引外商投资,并创建了一个开放的、可能还不健全的政治体系。格鲁吉亚的反对党有可能赢得政权,而且所有各方都遵守宪法。Rayfield的读者们可能觉得在过去的2500年,格鲁吉亚人民从没有像现在一样有这么多值得高兴的事。 /201406/305806。

If you thought erasable ink was cool, wait until you hear about today’s topic on A Moment of Science: electronic ink.如果你觉得可擦墨水很酷的话,那就等你听完今天所讲的这个话题---电子墨水后再下结论吧。To begin with a slightly technical explanation, electronic ink consists of three parts: millions of tiny, microscopic capsules, an oily liquid filling the capsules, and negatively charged colored chips or spheres floating inside the capsules. Electrical charges cause the colored chips or spheres to arrange themselves into letters, numbers, and other characters when the ink is sp on a surface.理论上来讲,电子墨水主要由三部分组成:数以百万的细小微型胶囊,填充胶囊的油状液体以及浮在胶囊里的带有负电荷的色芯片(或球体)。当墨水洒在物体表面时,色芯片在电荷的作用下就会形成字母、数字或文字。If that description is slightly confusing, try imagining electronic ink as consisting of millions of clear beach balls. Each ball contains hundreds of white Ping-Pong balls floating in blue dye. The Ping-Pong balls make the top of the beach ball appear white, while the bottom appears blue.如果我这么讲你有点难以理解的话,那就把电子墨水想象成是由数以百万的沙滩球组成。每个沙滩球球内都含有数百个白色的乒乓球浮在蓝色液体中。乒乓球会让沙滩球顶部呈现白色,而底部呈现出蓝色。Now imagine that you’ve sp millions of these beach balls on a wide, flat surface and gone up in a helicopter for a bird’s-eye view. You see an all-white field. Using a device to control the movement of the Ping-Pong balls, you cause some of them to sink, revealing the blue dye. With precise control, you could use the resulting patterns of light and dark to create characters.现在想象一下你将这些沙滩球放在一个宽而平的表面上,然后乘上直升机从上面俯瞰。你会看到一片白色。然后,你用设备来控制乒乓球的运动,让某些球下沉,呈现出蓝色。通过准确的控制颜色的深浅,你就可以写出字了。In a nutshell, that’s how electronic ink works. So what’s it good for? Electronic books, for one. In the near future we may leaf through a volume written with electronic ink that contain hundreds of different texts. With the push of a button, Shakespeare may morph into Dr. Seuss. Another push and the ink re-arranges itself into Crime and Punishment. No matter how it’s used, electronic ink is sure to jolt our understanding of the printed page.简单来说,这就是电子墨水的工作原理。那么电子墨水有什么好处呢?就拿电子书来举个例子,在不远的将来,我们可能会阅读用电子墨水写成的书卷,这些书卷包含着数百种书籍。只要轻轻一摁,莎士比亚就会变成瑟斯士,再摁一下,就会变成罪与罚。电子墨水无论怎么样被使用,它终将颠覆我们对于印刷页面的理解。。

All over the country, beach managers have tried to make beaches safer by discouraging the use ofglass bottles on the sand.在全国范围内,为了安全起见,主管沙滩的经理们都不鼓励把玻璃洒用于沙滩。Florida, however, has actually begun using glass as sand at the beach as a way to keep its shoresfriendly to both tourists and wildlife.然而佛罗里达州,开始用玻璃来代替沙撒在海滩上,以此来保护游客和野生动植物。A stable beach is important for human use and for many wildlife populations.一个稳定的沙滩对于人们的使用和许多野生动物种群来说是非常重要的。Each year, the oceansurf causes substantial erosion of these beaches as it carries tons of sand with it back into theocean.每年,海洋冲浪都会引起海滩的严重侵蚀,因为它会带着好几吨的沙重回大海。The most common way to restore the sand lost to erosion is to pipe it from the oceanfloor back up to the beach.储存沙最常见的方法就是用管子把它从海底重新运回海岸。This method, though, is expensive and does damage to the fragileecosystems on the ocean floor.这种方法不仅花费昂贵,而且也容易破坏海底脆弱的生态系统。In the search for an alternative to this costly and destructive piping method, scientists turned to crushed glass.在寻找可以代替这种昂贵的和破坏性的管道方法的过程中,科学家们转向了粗碎玻璃。The glass was made into pieces roughly two-hundredth-of-an-inch in size thatwere similar in shape and texture to ordinary sand.这种玻璃被做成0.0127厘米大小的类似于普通沙子的质地和形状的样子。The glass sand was then tested to make surethat it would not only look like sand, but would also behave like sand in the natural environment.他们对玻璃沙子进行测试,确保它不仅看起来像沙子,而且在自然环境中也能像自然沙子那样发挥作用。Researchers found that the glass sand was very similar to ordinary sand in terms of heat, moistureand oxygen levels.研究人员发现,玻璃沙子在热量,湿度和含氧量方面都非常类似于普通的沙子。They also determined that the glass sand was suitable for those who inhabit thebeach, from microorganisms to crabs and turtles.他们还发现玻璃沙子对于在海边居住的生物也同样适合,从微生物到螃蟹,再到海龟。Thanks to these scientists, today you can visitone of these lovely, sparkling beaches and even build a glass castle in the sand.多亏了这些科学家,今天你可以参观到这些可爱的,闪闪发亮的海滩,甚至于矗立于海滩中一座玻璃城堡。 201409/326390。