首页 >> 新闻 >> 正文


2017年12月12日 22:02:31来源:兰州晨报


  • bond markets债券市场A big number from VerizonVerizon的大手笔Companies are still taking advantage of low yields to raise debt各公司仍在利用低收益率提高债务水平Sep 14th 2013 |From the print editionDEBT crisis? What debt crisis? The biggest corporate-bond issue ever was completed this week. Verizon Communications, an American telecoms group, issued a whopping billion of bonds in order to finance the buy-out of Vodafone’s stake in its wireless operations. That shattered the previous record, Apple’s paltry billion issue earlier this year.债务危机?什么样的债务危机?史上最大的企业债券发行本周完成了。一家美国电信集团Verizon通讯为了付沃达丰持有的无线业务股权买断费用,发行了高达490亿美元的债券。这打破了此前的纪录,苹果在今年早些时候发行了现在看来微不足道的170亿美元的债券。The scale of Verizon’s offering may be unprecedented, but its foray into the bond markets is anything but. In the first eight months of this year .4 trillion of corporate bonds were issued worldwide, according to Dealogic, a data provider, compared with .3 trillion in the same period of 2012. Firms have been keen to lock in long-term financing at low yields, particularly since borrowing costs started rising after the Federal Reserve hinted in May at slowing its asset purchases.Verizon的发行规模可谓是前所未有的,但是这不是其首次尝试债券市场了。根据数据提供商Dealogic的数据,今年前8个月世界范围内有1.4万亿公司债券发行,2012年同期金额为1.3万亿。各公司一直热衷于以低收益率参与长期融资,尤其是自从美联储五月暗示放缓其资产购买之后,借贷成本开始上升。Oil and gas companies have been particularly enthusiastic issuers, according to Marcus Hiseman of Morgan Stanley, especially in the “Yankee” market where foreign businesses sell bonds, priced in dollars, mainly to American investors. Previously many foreign firms would issue debt in euros and swap the proceeds into dollars, but regulatory restrictions on banks make that much more expensive these days. This year 72% of investment-grade issuance has been in dollars, compared with 58% in , according to Morgan Stanley.据根士丹利的Marcus Hiseman表示,石油和天然气公司一直是特别积极的发行者,尤其是在美国市场,外国公司主要向美国投资者售卖以美元计价的债券。此前,许多外国公司用欧元发行债券,之后将受益转换成美元,但是对的监管限制规定使得这种做法在现在变得很昂贵。根据根士丹利的数据,今年72%的投资级发行都是以美元计价,相比之下去年只有58%。If companies fear that bond yields are set to rise (meaning that bond prices will fall), why are investors so keen to buy? There was plenty of demand to absorb the Verizon issue, for instance: orders reportedly reached 0 billion. One reason is that corporate bonds offer a sp (excess interest rate) over government bonds that is still attractive in historical terms. The average yield on ten-year investment-grade debt is 3.5%, compared with just 2.95% on Treasury bonds of the same maturity. The sheer size of the Verizon issue required it to be more generous towards investors, as did its BBB+ rating from Standard amp; Poor’s, towards the bottom end of the investment-grade category. The firm offered a yield of over 5% on its ten-year bonds, for example, more than two percentage points above the equivalent Treasury issue.如果企业担心债券收益率上升(这意味着债券价格会下跌),那么投资者为何这么热衷于购买呢?买入Verizon发行的债券需求很大,例如,据报道订单达到了1000亿美元。一个原因是企业债券相比国债提供一个差额(更高的利率),从历史上看,仍然具有吸引力。十年期投资级债券的平均收益率是3.5%,而相同期限的国债收益率只有2.95%。Verizon发行债券的规模如此之大,这要求其对投资者提供更高的收益,标准普尔对其作出的评级是BBB+,是投资级类别的最低等级。该公司十年期债券的收益率超过5%,比国债的收益率高了两个百分点。Many central banks, which hold a large part of their reserves in dollars, remain enthusiastic buyers of corporate debt. In addition, many investors in corporate debt are specialist fund managers who aim to beat the benchmark specific to their asset class, points out Paul Young of Citigroup; they care more about whether they pick the right bonds, as they are able to hedge the underlying interest-rate risk.许多持有大量美元储蓄存款的中央仍然热衷于购买企业债券。此外,花旗集团的样子刚指出,许多企业债券的投资者是专业的基金经理,他们的目标是打破特定资产类别的基准,他们有能力抵消相关利率风险,所以他们更关心是否挑选了正确的债券。The influx of money nonetheless causes some to worry. The corporate-bond market is a lot less liquid than it used to be, thanks largely to the effect of regulations on the willingness of banks to hold large inventories of corporate debt. This could cause a problem should bond investors want to sell their holdings in a rush. For the moment, however, that does not seem likely. Corporate balance-sheets look strong and the default rate over the past 12 months, even on speculative debt, was just 2.9%, according to Moody’s, another ratings agency.资金潮仍然引起了一些担忧。企业债券市场比起以前流动性变差了,这在很大程度上是由于对持有大量企业债券所出台的法规限制。这可能会导致债券投资者想要急于出售其所持债券。然而,就目前而言,看起来不是这样。企业资产负债表看起来很漂亮,根据另一评级机构穆迪的数据,在过去的12个月,就算是投机性债务的违约率也只有2.9%。 /201309/257345
  • Science and technology科学技术Human reproduction人类繁衍Life begins at 4545岁也能生娃Hope for older mothers高龄母亲的福音WHEN it comes to reproduction, men have it easy.讲到繁衍,男人表示压力很小。Almost to the end of their lives most have an ample supply of sperm.大多数人直到去世前都拥有充足的精子。Women are not so lucky.女人可就没这么幸运了。They are born with a supply of eggs that typically runs out when they reach middle age.人到中年,她们就会耗尽出生时携带的卵子。That could be about to change, however.不过,这一情形很快就能得到改变。Researchers have confirmed that women harbour ovarian stem cells, and that these can give rise to new eggs.研究者们实,女人拥有卵巢干细胞,而这种细胞能成为新的卵细胞的来源。Stem cells have the ability to divide continuously and to change into different types of cells.干细胞具有不断分裂的潜力,可以分化成许多种类的细胞。Stem cells from adults can produce a variety of cell types, in addition to those that make up the tissue in which they are found.成人干细胞不仅可以分化成其来源组织的细胞,还能分化成其它细胞。In 2004 Jonathan Tilly of Harvard Medical School and his colleagues discovered stem cells in mouse ovaries.2004年,哈弗医学院的Jonathan Tilly及其同事在老鼠卵巢里发现了干细胞。Since then it has been shown that these ovarian stem cells can develop into eggs, be fertilised and produce perfectly healthy mouse pups.迄今已经实,此类卵巢干细胞能够分化成为卵细胞,卵细胞在受精后还能发育成健康的鼠宝宝。But researchers have been reluctant to believe that something similar might be possible in humans.但是研究者尚不能确信人类也存在类似机能。Proving that this was indeed the case was tricky.想要弄清真相有些困难。Human ovarian tissue—especially from young, healthy donors—is not easy to come by.人类卵巢组织很难找到,健康的年轻捐献者的组织更难寻觅。Dr Tilly’s breakthrough came when he discovered that a former colleague, Yasushi Takai of Saitama Medical University in Japan, had in his freezer healthy ovarian tissue from 30 patients who had changed sex.幸而Tilly士发现他的前同事—日本埼玉医科大学的Yasushi Takai在冰箱里存放了30个变性人不再需要的健康卵巢组织,取得了突破。Using a sophisticated cell-sorting technique, the researchers developed a way to identify ovarian stem cells that works for both mice and humans.研究人员运用尖端的细胞分选技术,找出方法,实人类和老鼠身上都存在卵巢干细胞。Then they took the human ovarian stem cells, labelled them with a green fluorescent protein and put them back into a slice of human ovary.随后,他们分离出人类卵巢干细胞,用荧光蛋白做上标记再把它植入一片人类卵巢组织。The glowing green cells soon produced a brand new crop of human eggs, according to their findings published this week in Nature Medicine.这片组织被移植到了活鼠体内,使其保持正常卵巢的机能。他们本周发表在《自然医学》上的结果称,这些绿芒闪烁的细胞很快制造出了一批人类卵细胞。Offshoring fertilisation国外受精Fertilising these eggs for experimentation is forbidden in America.美国禁止为实验用的卵细胞受精,Britain’s Human Fertilisation and Embryology Authority, however, will allow it in certain cases.不过英国的人类受精和胚胎学将在某些研究中允许给卵细胞授精。So next month Dr Tilly will take some of his stem cell booty to Edinburgh to collaborate with Evelyn Telfer, who has developed a technique for growing human eggs from an early stage.所以,下个月Tilly士将带着卵细胞去爱丁堡与Evelyn Telfer合作。Evelyn Telfer掌握了用卵母细胞培育卵细胞的技术,She holds a licence to fertilise them experimentally.持有给试验用细胞授精的许可。The discovery could revolutionise infertility treatment for women in several ways.这项发现会是女性不育症治疗的一场革命。For one thing, research has shown that in mice, even aged ovaries contain ovarian stem cells.一方面,老鼠体内衰老的卵巢里也有卵巢干细胞;And when those stem cells are placed into a young ovary, they will develop healthy eggs.将这些细胞移植到年轻的卵巢中后,它们能制造健康的卵子。This raises the possibility that, one day, women of advanced age could have their own biologically related children.这意味着将来的某天,年龄较大的妇女也能拥有生物学意义上的自己的孩子。Currently, many women over 45 have to make do with in-vitro fertilisation using the egg of a younger woman.目前,许多45岁以上的妇女只能凑合着用年轻女人的卵细胞进行体外受精。Other treatments will become available sooner.另一种疗法也将很快得到应用。OvaScience, a fertility company based in Boston which has exclusive rights to exploit Dr Tilly’s research on mammalian ovarian stem cells, will begin offering a novel treatment in July.波士顿的OvaScience公司独家开发Tilly士的哺乳动物卵巢干细胞细胞研究。This uses a woman’s own stem cells to provide her eggs with extra energy by creating fresh mitochondria—sub-units that exist within cells and supply them with energy.今年7月,该公司将开始提供一种全新的疗法:使用卵巢干细胞制造线粒体,给妇女的卵细胞增添活力。They too can become scarcer and less productive with age.线粒体的数量和活力也会随着年龄增长而递减。Previous studies have shown that boosting mitochondria can dramatically increase the success rates of IVF.此前的研究表明,增加线粒体数量能极大提高体外受精的成功率。When it comes to reproduction, men will still have it easier for some time.谈起繁衍来,男人还能优哉游哉一阵子。But women are catching up.不过,女人即将迎头赶上。 点击此处下载本期经济学人讲解PDF与音频字幕 /201307/246577
  • Science and technology科学技术Searching for aliens寻找外星人The wow factor防止再次意外A new citizen-science project will improve the chances of finding ET一个新的平民科学项目可以增大找到地外智慧的机会EVER since 1993, when funding from Americas space agency, NASA, was cut, the Search for Extraterrestrial Intelligence, which scans the sky looking for radio signals from intelligent aliens, has been inventive in its methods.自从1993年,寻找地外智慧在失去了美国航天局的资助后,开辟了一个新的的研究途径。In particular, it was one of the pioneers of the field of citizen science, in which interested amateurs are recruited to help professionals crunch data.具体来说,这个新途径是平民科学的先驱之一,它邀请感兴趣的外行人来帮助专家处理海量数据。In 1999 it started SETIhome, an application that uses spare processing power on volunteers computers to sift the information generated by its radio telescopes.1999年,在家寻找地外智慧项目启动了,它通过一个应用程序利用志愿者的电脑上闲置的计算资源来筛选来自射频望远镜的信息。These days, SETIhome boasts more than 1m users.今天,在家寻找地外智慧已经号称拥有超过100万的用户。On February 29th the SETI Institute launched another citizen-science project.2月29号,寻找地外智慧协会启动了一个新的平民科学项目。This time, though, its researchers are less interested in the digital computers on volunteers desks than in the biological ones between their ears.这次,研究人员们更加感兴趣的是志愿者的双眼,而不是他们桌上的计算机。实时寻找地外智慧,SETILive, as the project is called, hopes to use the pattern-recognition capabilities of brains to distinguish interesting signals from the cacophony of interference generated by the denizens of planet Earth—and to do so in real time.就像它的名称所说,它希望利用我们大脑的模式识别能力来辨认出夹杂在由地球原住民产生的信号中的有趣信号,实时地。The basic idea behind SETI is to look for distinctive radio-frequency emissions that might come from advanced aliens rather than natural sources like stars.寻找地外智慧的基本想法是寻找来自高级地外生命而不是其他自然来源如恒星的射频信号。To do this, the SETI Institute uses an instrument called the Allen Telescope Array—a group of 42 small radio-telescope dishes in California, partly paid for by the eponymous co-founder of Microsoft.其协会依靠的工具是坐落在加州的艾伦望远镜阵列,它由42个小的射频望远镜组成,因为微软的共同创始人提供了部分资金而得名。Unfortunately, some parts of the radio spectrum are full of signals created by Earthlings, rather than aliens.不幸的是,来自地球居民而不是外星人的信号挤满了射频频谱的一部分。Everything from passing satellites and tumbling space junk to ground-based radar and even the ignition systems of nearby cars can generate spurious radio waves that confuse the software.各种各样的来源产生了欺骗性的信号迷惑了相关软件,这些来源包括划过天空的卫星和翻滚的太空垃圾,地面上的雷达甚至是附近汽车的点火系统。Until now, the project has dealt with that by ignoring the more crowded bits of the spectrum.目前,项目只能避开这些拥挤的频段。But SETILive will bring them into play.但是实时寻找地外智慧就可以把这些被迫忽略的频段拿来一起分析。It will do so by feeding pictorial representations of data from these noisy chunks of the spectrum to its users in the hope that they will be able to filter out the noise and spot potentially interesting signals buried behind the radio clutter from Earth.它把在这些充满噪声的拥挤频段内的信息转换成图像发送给用户,希望他们能够在这些噪音中发现潜在特别的信号。Those interesting signals will not necessarily have come from alien civilisations, says Chris Lintott,这些特别的信号不一定就来自外星文明。Chris Lintott说。an astrophysicist at Oxford University who helps to run Zooniverse, a citizen-science website that manages several projects, including SETILive.他是牛津大学的天文物理学家,But even if they do not, some new astronomical phenomena may be discovered by the project. And as the various sources of interference become better characterised, the results will be fed back into the automated-search algorithms, improving their ability to deal with Earth-generated noise.帮助运作一个管理了包括实时寻找地外智慧在内的一些项目的平民科学网站-宇宙动物园。Other citizen-science projects aly use the superior pattern-recognition capabilities of human wetware, but SETILive is different from these in one important way.其他一些平民科学项目已经在利用人类自身湿件的模式识别能力了,但是实时寻找地外智慧在一个重要方面与它们都不同。Rather than having its users pore at leisure over stored data, aliens are hunted on the fly.外星人是被即时捕捉到的,而不是用户从容地凝视那些储存好了的数据。Users logging on to the projects website view information that is hot from the Allen Array.用户登录项目网站后看到的信息是刚刚从艾伦望远镜阵列传来的。They have to work quickly, though.他们还必须看得快些,Every 90 seconds, the array switches to looking at a different star, or a different frequency range, and a new image is generated.因为每隔90秒望远镜阵列就会切换观测另外一个星体或者一个不同的频段,一幅新的信息转换成的图像就会显示出来。If, however, the humans do spot something interesting, the array can be told within three minutes to switch back to observing the star or range in question, to see if the signal is still there.如果万一有人确实看到了一些特别的信息,望远镜阵列会在3分钟之内切换回那个特定的星体或者频段,看看信号还是否在那。That is a big advantage, says Dr Lintott.Lintott士说这是一个很大的优势。Volunteers working on SETIhome have found plenty of interesting signals,在家寻找地外智慧的志愿者们就发现过很多有趣的信号,but because the data they analyse are often months old, those signals have usually vanished by the time anyone gets around to checking up on them.但是因为那些数据大多是几个月之前的,当研究人员有机会回头查看时通常它们都已经消失了。The most famous example of such delayed discovery, though it long predates the start of SETIhome, is the so-called Wow! signal.这类延迟事件最出名的一次,尽管早在在家寻找地外智慧启动之前,是一个被称为Wow!的信号。This signal, which looked exactly like the sort of thing astronomers had theorised aliens might use to get in touch was spotted in telescope printouts in 1977.1977年,这个信号在一个望远镜输出文件中被发现了,它完全符合天文学家理论预测的外星人用来和外界联系的特征。It was a powerful, finely tuned broadcast at the most important natural frequency for radio astronomers—the one generated by the flipping spin of the electron in a hydrogen atom.这个信号不仅强烈,而且精确地在射频天文学中最重要的自然频率上发射出来。But by the time astronomers had noticed it and set their instruments up to double-check, the signal had vanished.但是等到天文学家发现并且使用仪器进行二次确认的时候它已经消失了。If a second Wow! signal were discovered by SETILive, astronomers could focus on it almost immediately.如果第二个Wow!信号被实时寻找地外智慧发现,天文学家就可以几乎立即对准它。First contact with aliens, then, might take place not in a lab full of computers but late one night in a suburban bedroom. There could be a film in that.第一次与外星人的接触,说不定就不是发生在满是电脑的实验室里,而是深夜在一个城郊住宅区的卧室中。果真如此就可以拍一部电影了。 点击此处下载本期经济学人讲解PDF与音频字幕 /201307/246413
  • Artificial intelligence and psychology人工智能和心理学The computer will see you now现在电脑能给你看病了A virtual shrink may sometimes be better than the real thing有时候,虚拟缩小版反而比实际事物更好ELLIE is a psychologist, and a damned good one at that. Smile in a certain way, and she knows precisely what your smile means. Develop a nervous tic or tension in an eye, and she instantly picks up on it. She listens to what you say, processes every word, works out the meaning of your pitch, your tone, your posture, everything. She is at the top of her game but, according to a new study, her greatest asset is that she is not human.Ellie是一名心理学家,而且长于此道。面带职业化微笑的她,清楚滴知道你每个笑容的含义。即便是简单的神经抽搐或者眼神紧张,她也能立刻注意到这个细节。她仔细聆听你的表达,分辨每一个字词,研究你每个音调、口音、手势等所有小动作的含义。最新研究认为,她处在行业顶端的最大优势在于,她不是人类。When faced with tough or potentially embarrassing questions, people often do not tell doctors what they need to hear. Yet the researchers behind Ellie, led by Jonathan Gratch at the Institute for Creative Technologies, in Los Angeles, suspected from their years of monitoring human interactions with computers that people might be more willing to talk if presented with an avatar. To test this idea, they put 239 people in front of Ellie to have a chat with her about their lives. Half were told they would be interacting with an artificially intelligent virtual human; the others were told that Ellie was a bit like a puppet, and was having her strings pulled remotely by a person.当面临艰难决定,或可能尴尬的问题的时候,人们一般并不会告诉医生他需要听到的内容。然而来自洛杉矶的创新技术研究所的研究人员,在Jonathan Gratch的领导下,根据多年使用电脑监控人际交流的结果,认为人们更愿意对着虚拟头像吐露真心。为测试这一想法,他们请了239人同Ellie当面交流他们的生活。其中一半被告知实情,即他们同人工智能在互动;同时误导另外一半,告诉他们Ellie就像是一个傀儡,被某个人远程操控。Designed to search for psychological problems, Ellie worked with each participant in the study in the same manner. She started every interview with rapport-building questions, such as, “Where are you from?” She followed these with more clinical ones, like, “How easy is it for you to get a good nights sleep?” She finished with questions intended to boost the participants mood, for instance, “What are you most proud of?” Throughout the experience she asked relevant follow-up questions—“Can you tell me more about that?” for example—while providing the appropriate nods and facial expressions.为研究心理问题而设计的Ellie以相同的方式同每个参与者互动。每次会谈她都以拉家常的问题开始,比如“你从哪儿来?”然后继以更医学性的问题,比如“你晚上睡眠质量如何?”最后她的问题会刺激参与者的情绪,比如“你最骄傲的事是什么?”在整个过程中,她会问到相关的后继问题,比如“能不能多聊聊这个?”同时还会适时地点头,做出恰当地面部表情。Lie on the couch, please请躺在沙发上During their time with Ellie, all participants had their faces scanned for signs of sadness, and were given a score ranging from zero to one.Also, three real, human psychologists, who were ignorant of the purpose of the study, analysed transcripts of the sessions, to rate how willingly the participants disclosed personal information.在同Ellie共处的时候,所有的参与者的面部都会被扫描,以寻找悲伤的特征,并评以0到10分。同时,三位真正的人类心理学家,在对此研究的目的一无所知的情况下,分析会谈的视频,并排出参与人员披露个人信息的意愿。These observers were asked to look at responses to sensitive and intimate questions, such as, “How close are you to your family?” and, “Tell me about the last time you felt really happy.” They rated the responses to these on a seven-point scale ranging from -3 to +3. All participants were also asked to fill out questionnaires intended to probe how they felt about the interview.这些观察人员要注意对敏感而亲密的问题的回答,比如“你同你家庭有多亲密?”和“告诉我你上次觉得真的高兴是什么时候。”他们根据七分制对这些回答进行排序,-3表明完全不愿意表露信息,+3表示非常愿意。所有的参与人员也要填写调查问卷,以说明他们对此次会谈的感觉。Dr Gratch and his colleagues report in Computers in Human Behaviour that, though everyone interacted with the same avatar, their experiences differed markedly based on what they believed they were dealing with. Those who thought Ellie was under the control of a human operator reported greater fear of disclosing personal information, and said they managed more carefully what they expressed during the session, than did those who believed they were simply interacting with a computer.Gratch士及其同事在《人类行为同电脑》上报道称,尽管每个人都与同一个头像进行互动,他们的体验却显著地取决于他们认为自己所交流的对象。同认为仅仅是同电脑互动的人相比,那些认为Ellie是在人类控制下的参与者更担心揭露个人信息,并认为在会谈期间,他们对表达的内容更细心在意。Crucially, the psychologists observing the subjects found that those who thought they were dealing with a human were indeed less forthcoming, averaging 0.56 compared with the other groups average score of 1.11. The first group also betrayed fewer signs of sadness, averaging 0.08 compared with the other groups 0.12 sadness score.重要的是,监测这一过程的心理学家发现,那些认为是在同人类交流的参与者,确实更内向。相比于另一组的1.11的平均值,他们的平均值仅为0.56。第一组同样泄露出了较少的悲伤特征,平均0.08,而另一组的悲伤得分为0.12。This quality of encouraging openness and honesty, Dr Gratch believes, will be of particular value in assessing the psychological problems of soldiers—a view shared by Americas Defence Advanced Research Projects Agency, which is helping to pay for the project.Gratch士认为,鼓励开放和诚实的质量将在评估军人的心理学问题过程中起到重要作用。这一观点得到了美国国防高级研究计划局的认同。后者同时也是此项目的赞助方。Soldiers place a premium on being tough, and many avoid seeing psychologists at all costs. That means conditions such as post-traumatic stress disorder, to which military men and women are particularly prone, often get dangerous before they are caught. Ellie could change things for the better by confidentially informing soldiers with PTSD that she feels they could be a risk to themselves and others, and advising them about how to seek treatment.军人对表现坚强尤其看重,而且许多人竭力避免去看心理医生。然而许多军人都很容易产生创伤后应激障碍的问题。这意味着在发现的时候,往往这一问题已经变得危险。Ellie能够改变这一现状,秘密通知她认为患有创伤后应激障碍的军人可能对患者自身及其他人构成威胁,并建议他们如何寻求治疗。If, that is, a cynical trooper can be persuaded that Ellie really isnt a human psychologist in disguise. Because if Ellie can pass for human, presumably a human can pass for Ellie.这一切的前提是,玩世不恭的兵哥哥要相信Ellie真的不是伪装了的人类心理学家。毕竟如果Ellie能够欺骗人类,那人类也能欺骗他。 /201408/321924
分页 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29