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2018年01月23日 23:54:02来源:度排名快问答网

  • Scientists have sequenced the genome of the world#39;s oldest continuously surviving cancer, a transmissible genital cancer that affects dogs. This cancer, which causes grotesque genital tumors in dogs around the world, first arose in a single dog that lived about 11,000 years ago. The cancer survived after the death of this dog by the transfer of its cancer cells to other dogs during mating. The genome of this 11,000-year-old cancer carries about two million mutations -- many more mutations than are found in most human cancers, the majority of which have between 1,000 and 5,000 mutations. The team used one type of mutation, known to accumulate steadily over time as a ;molecular clock,; to estimate that the cancer first arose 11,000 years ago.一般来说,癌症在宿主体内产生后,会随着宿主的死亡而灰飞烟灭。不过,据《科学》1月23日报道,有一脉“犬传染性性病肿瘤”(CTVT)已经存在了1.1万年,可能是有史以来最古老的癌症。该肿瘤的第一任宿主在品种上接近哈士奇,其基因至今仍保留在肿瘤细胞中。这一脉CTVT自1.1万年前首次出现以后,非但没有消亡,反而通过交配在犬类中广泛传播。这项研究已经在学术杂志《科学》上面发表。科研人员已经完成了CTVT的基因排序工作,发现它已经有了大约200万个变种。在人类中,癌症的变种一般在1000至5000个之间。研究团队分析了其中一个变种,认定CTVT最早出现在1.1万年之前。;The genome of this remarkable long-lived cancer has demonstrated that, given the right conditions, cancers can continue to survive for more than 10,000 years despite the accumulation of millions of mutations,; says Dr Elizabeth Murchison, first author from the Wellcome Trust Sanger Institute and the University of Cambridge. The genome of the transmissible dog cancer still harbors the genetic variants of the individual dog that first gave rise to the cancer 11,000 years ago. Analysis of these genetic variants revealed that this dog may have resembled an Alaskan Malamute or Husky. It probably had a short, straight coat that was colored either grey/brown or black. Its genetic sequence could not determine if this dog was a male or a female, but did indicate that it was a relatively inbred individual.论文第一作者、来自剑桥大学的伊丽莎白?默奇森士说:“这个癌症如此长寿,实在难得。它的基因说明,在适当的环境下,癌症能够存活1万年以上,并衍生出数百万个变种。”这个癌症基因至今仍保有1.1万年前其首任宿主的基因。分析表明,这位“始作俑者”在品种上和哈士奇非常相似,毛发短而直,可能以灰、褐、黑等颜色为主。默奇森说:“我们不知道为什么这一条会患上传染性癌症。”;We do not know why this particular individual gave rise to a transmissible cancer,; says Dr Murchison, ;But it is fascinating to look back in time and reconstruct the identity of this ancient dog whose genome is still alive today in the cells of the cancer that it spawned.; Transmissible dog cancer is a common disease found in dogs around the world today. The genome sequence has helped scientists to further understand how this disease has sp. ;The patterns of genetic variants in tumors from different continents suggested that the cancer existed in one isolated population of dogs for most of its history,; says Dr Murchison. ;It sp around the world within the last 500 years, possibly carried by dogs accompanying seafarers on their global explorations during the dawn of the age of exploration.;谈及CTVT的传播史时,默奇森说:“不同大陆上肿瘤变种的范式表明,肿瘤长期局限在一个孤立的犬类种群里,在过去500年内才在全世界传播开来。这些犬类也许是在探险时代的早期跟随主人们周游世界的。” 自然环境下的传染性癌症非常罕见。癌症能够在宿主的不同器官中扩散,但很难传染给其他个体。作者之一麦克?斯特拉顿说:“这个传染性犬类癌症的基因会帮助我们研究癌症传染的过程。虽然传染性癌症非常罕见,但我们必须做好准备,以防类似疾病在人类或者其他动物中出现。另外,通过研究这个古老的癌症,我们能够更加广泛地了解影响癌症进化的因素。Transmissible cancers are extremely rare in nature. Cancers, in humans and animals, arise when a single cell in the body acquires mutations that cause it to produce more copies of itself. Cancer cells often sp to different parts of the body in a process known as metastasis. However, it is very rare for cancer cells to leave the bodies of their original hosts and to sp to other individuals. Apart from the dog transmissible cancer, the only other known naturally occurring transmissible cancer is an aggressive transmissible facial cancer in Tasmanian devils that is sp by biting. ;The genome of the transmissible dog cancer will help us to understand the processes that allow cancers to become transmissible,; says Professor Sir Mike Stratton, senior author and Director of the Sanger Institute. ;Although transmissible cancers are very rare, we should be prepared in case such a disease emerged in humans or other animals. Furthermore, studying the evolution of this ancient cancer can help us to understand factors driving cancer evolution more generally.;美国国家卫生研究院的癌症遗传学家伊莱恩?奥斯特兰德说:“这绝对令人兴奋。成千上万年来,犬类一直传播、照顾这一脉的癌症细胞,现在我们有机会研究它了。 /201401/274271。
  • Some 87 per cent of gum-chewing teenagers who suffer regular headaches can cure themselves by giving up chewing gum, new research suggests.最新研究表明,那些爱嚼口香糖又常容易头痛的青少年中,87%的人会在停止咀嚼口香糖后症状消失。Scientists at the Tel Aviv University-affiliated Meir Medical Centre, in Israel, found that most adolescents who give up the habit experience significant relief.以色列特拉维夫大学附属梅尔医学中心的科学家发现,绝大多数青少年在改掉咀嚼口香糖的习惯后头痛症状明显减轻。The scientists, led by Dr Nathan Watemberg, believe the finding could allow doctors to cure thousands of patients of migraines and tension headaches without the need for additional tests or medication.由Nathan Watemberg医生领衔的研究组认为,该发现将使医生在不借助任何额外测试和药物治疗的前提下治愈数千患者的偏头痛和紧张性头痛。‘Out of our 30 patients, 26 reported significant improvement and 19 had complete headache resolution,’ said Dr Watemberg.Watemberg医生表示,(在该方法的引导下)参与实验的30名患者中,26名的症状有显著改善,其中有19位患者头痛症状完全消失。‘20 of the improved patients later agreed to go back to chewing gum, and all of them reported an immediate relapse of symptoms.’“20名症状缓和的患者随后同意恢复咀嚼口香糖习惯,然后他们的头痛症状很快复发。”Headaches are common in childhood and become more common and frequent during adolescence, particularly among girls.头痛现象普遍存在于儿童时期,并且在青少年时期日益普遍和发作频繁,女生中这种现象尤为明显。Typical triggers are stress, tiredness, lack of sleep, heat, games, noise, sunlight, smoking, missed meals, and menstruation.常见的触发因素包括压力、疲劳、缺乏睡眠、发热、视频游戏、噪音、日光、吸烟、不吃饭和生理期。But until now there has been little medical research on the relationship between gum chewing and headaches.但直到现在,很少有关于嚼口香糖和头痛之间关系的医学研究。At Meir Medical Centre#39;s Child Neurology and Child Development Centre, Dr Watemberg noticed that many patients who reported headaches were daily gum chewers.在梅尔医学中心儿童神经病学和发展中心,Watemberg医生注意到很多父母说起换头痛的孩子都常嚼口香糖。Dr Watemberg found that in many cases, when patients stopped chewing gum at his suggestion, they got substantially better.Watemberg发现很多案例中,当父母根据他的建议不让孩子再嚼口香糖时,孩子们头痛的状况会大为改善。Taking a more statistical approach, he asked 30 patients between six and 19 years old, who had chronic migraine or tension headaches and chewed gum daily, to quit chewing gum for one month. They had chewed gum for at least an hour a day and some had chewed for more than six hours a day.为了更科学地研究,他要求参与实验的30名6-19岁间,患有慢性偏头痛和紧张性头痛的哎嚼口香糖患者在一个月内停止嚼口香糖。这些患者平时每天至少嚼一个小时口香糖,有的甚至每天嚼口香糖超过6小时。After a month without gum, 19 of the 30 patients reported that their headaches went away entirely and seven reported a decrease in the frequency and intensity of headaches.一个月没嚼口香糖后,19名患者报告头痛症状完全消失,7人报告头痛发作频率和强度均有所下降。To test the results, 20 of them agreed to resume gum chewing for two weeks. All of them reported a return of their symptoms within days.为了测试结果,其中20人回复嚼口香糖的习惯两个星期,然后所有人表示几天后头痛发作。Two previous studies linked gum chewing to headaches, but offered different explanations.之前有两个关于嚼口香糖和头痛之间关系的研究,但得出完全不同的结论。One study suggested that gum chewing causes stress to the temporomandibular joint, or TMJ - the place where the jaw meets the skull.其中一个结论认为咀嚼口香糖的动作导致颞颌关节——下颔与头骨结合处的压力。The other study blamed aspartame, the artificial sweetener used in most popular chewing gums.另一个研究则归咎于阿斯巴甜——口香糖中最常见的人工甜味剂。TMJ dysfunction has been shown to cause headaches, while the evidence is mixed on aspartame. Dr Watemberg favours the TMJ explanation.颞骨关节功能紊乱已被明会导致头痛,但其中的据与阿斯巴甜有关。Watemberg医生倾向于颞骨关节功能紊乱导致头痛的结论。Gum only has a flavour for a short period of time, suggesting it does not contain much aspartame, he says.他说,口香糖的口味只能停留一小段时间,其中阿斯巴甜的含量不高。If aspartame caused headaches, he reasons, there would be a lot more headaches from diet drinks and artificially sweetened products which also contain it.如果阿斯巴甜引起头痛,那膳食饮料和其他含有阿斯巴甜的人工加糖食品会导致更多的头痛。On the other hand, people chew gum well after the taste is gone, putting a significant burden on the TMJ, which is aly the most used joint in the body, he says.另一方面,人们在口香糖甜味消失后继续咀嚼,会给身体最常用的颞骨关节带来更多负担。‘Every doctor knows that overuse of the TMJ will cause headaches,’ said Dr Watemberg. ‘I believe this is what#39;s happening when children and teenagers chew gum excessively.’他说道,“每个医生都知道颞颌关节负担过重会引起头痛,我相信青少年们过度咀嚼口香糖导致了这一状况。” /201312/270083。
  • Among the many acid pleasures of the work of Roberto Bola#241;o, who died at 50 in 2003, is his idea that culture, in particular literary culture, is a whore. In the face of political repression, upheaval and danger, writers continue to swoon over the written word, and this, for Bola#241;o, is the source both of nobility and of pitch-black humor. In his novel “The Savage Detectives,” two avid young Latino poets never lose faith in their rarefied art no matter the vicissitudes of life, age and politics. If they are sometimes ridiculous, they are always heroic. But what can it mean, he asks us and himself, in his dark, extraordinary, stinging novella “By Night in Chile,” that the intellectual elite can write poetry, paint and discuss the finer points of avant-garde theater as the junta tortures people in basements? The word has no national loyalty, no fundamental political bent; it’s a genie that can be summoned by any would-be master. Part of Bola#241;o’s genius is to ask, via ironies so sharp you can cut your hands on his pages, if we perhaps find a too-easy comfort in art, if we use it as anesthetic, excuse and hide-out in a world that is very busy doing very real things to very real human beings. Is it courageous to Plato during a military coup or is it something else?罗贝托·波拉尼奥(Roberto Bola#241;o)于2003年逝世,享年50岁,他的作品中有很多尖刻的欢乐,比如他认为文化是个婊子,特别是文学文化。面对政治压迫、巨变与危险,作家们依然迷恋文字,对于波拉尼奥来说,这是崇高感与黑色幽默的源泉。在他的小说《荒野侦探》(The Savage Detectives)中,两个热心的拉丁美洲年轻诗人一直都未失去对纯净艺术的信念,不管年龄增长,生活与政治发生变迁。他们有时很可笑,但他们一直都有英雄气概。但在他那非凡的、令人不安的中篇小说《智利之夜》(By Night in Chile)中,他问我们,也扪心自问:当军政府在地下室拷问他人的时候,知识分子精英能写诗,能绘画,能讨论先锋戏剧中更精妙的东西,这一切究竟有什么意义?文字没有国界、没有政治倾向;是任何想要成为主人者都能召唤出来的精灵。波拉尼奥的精灵以仿佛能切断读者双手般的犀利反讽发问:我们是不是太容易就在艺术中找到安慰,这个世界忙着对生活中真实的人们做出真实残酷的事情,而我们是不是太容易就把艺术当做麻醉、借口与隐藏之地了?在一场军事政变中阅读柏拉图究竟是一种勇敢,还是别的什么?“Nazi Literature in the Americas,” a wicked, invented encyclopedia of imaginary fascist writers and literary tastemakers, is Bola#241;o playing with sharp, twisting knives. As if he were Borges’s wisecracking, sardonic son, Bola#241;o has meticulously created a tightly woven network of far-right littérateurs and purveyors of belles lettres for whom Hitler was beauty, truth and great lost hope. Cross-referenced, complete with bibliography and a biographical list of secondary figures, “Nazi Literature” is composed of a series of sketches, the compressed life stories of writers in North and South America who never existed, but all too easily could have. Goose-stepping caricatures à la “The Producers” they are not; instead, they are frighteningly subtle, poignant and plausible. Like Leni Riefenstahl, the artistes Bola#241;o invents share a certain Romantic aesthetic, a taste for the classic and nonvulgar, a dislike of “cacophony” and a lurking sense that something has gone terribly wrong in the modern world — that children, for instance, have been “stolen and raised by inferior races” and that a better world in the form of the Fourth Reich is imminent. There is little to no mention of Jews or other undesirables; there are no death camps; World War II is a passing reference at best. Instead, with a straight face, Bola#241;o narrates the Nazi writers’ tireless imaginations, their persistence in the face of a world history that goes against them, their contrarian determination as they continue to write books that go un, unreviewed and largely unnoticed. They’re the losers but, with incredible passion, they remain steadfastly in denial of that fact, churning away at their refutations of Voltaire, Rousseau and Sartre; their verses vindicating Il Duce; their novels decrying the decline of piety; their Aryan literary societies. Like Riefenstahl, they find the highest beauty in a particular sort of symmetry and order that only in retrospect seems indubitably fascist. Horribly, persistently, they have a vision that they are incapable of giving up.《美洲纳粹文学》(Nazi Literature in the Americas)是一部顽皮的、杜撰出来的百科全书,里面记载了想象出来的纳粹作家和文学风潮领头人,书中波拉尼奥如同在挥舞一把犀利、扭曲的刀子。他仿佛尔赫斯(Borges)爱冷笑的淘气儿子,小心翼翼地创造出一张严密的,由极右文学家与美文创作者构成的大网,对于他们来说,希特勒意味着美、真理与伟大的失落希望。《美洲纳粹文学》由一系列人物速写组成,是虚构的南北美洲作家们的生平简史,还有参考书目和二流人物的传记书目为它提供相互参照和补充,但生活里很容易找到这样的人。他们并不是《金牌制作人》(The Producers)中踢着正步的漫画式人物,而是极度微妙、深刻、真实可信。波拉尼奥创造出的人物就像雷尼·瑞芬舒丹(Leni Riefenstahl)一样,信奉浪漫主义美学,有古典和新平民审美,讨厌“不和谐”,潜意识里认为现代世界是大错特错的——比如说,他们觉得孩子们“被低等种族偷窃和养育”,觉得在第四帝国统治之下,更好的世界近在眼前。书中没有提到犹太人和其他不受欢迎的人;也没有集中营;“二战”顶多只是已经过去的东西。相反,波拉尼奥一本正经地叙述纳粹作家们无穷尽的想象,他们一直顽强对抗着不利于自己的世界史,他们特立独行地写着无人阅读、无人、基本无人关注的书籍。他们是失败者,但又以惊人的热情,坚定不移地对抗他们是失败者这个事实,同时还不断驳斥伏尔泰(Voltaire)、卢梭(Rousseau)和萨特(Sartre);他们用诗歌为墨索里尼辩护、他们的小说哀悼神性的衰亡;他们结成雅利安文学社团。和瑞芬舒丹一样,他们在特定形式的对称与秩序中发现至上之美,这种对称与秩序人们只有在事后才觉得是法西斯主义无疑。他们有一种既可怕又顽固的幻觉,认为自己不能放弃。They are, in other words, writers. Substitute, say, “language poetry” for “fascism” and the trajectory of these invented lives would be much the same as they are for the busy networks of real writers Bola#241;o knew from the inside out. Whereas in “By Night in Chile” Bola#241;o’s dissection of hypocrisy and bad faith (the main character is a morally bankrupt priest allied with the junta) is swift and merciless, here it is not only as if the writer in him couldn’t keep himself from filigreeing in endless perfect and revealing details about his lost souls and their laughable oeuvres, but also as if he couldn’t entirely resist them. As a fellow traveler, he probably knew only too well what it is to pit the invented world on your ratty pages against the firmly stated values of the real world. The imaginary Ernesto Pérez Masón, who pounds away at his novella that is “an erotic and fiercely anti-U.S.A. fantasy, whose protagonists were General Eisenhower and General Patton”; the mysterious beauty Daniela de Montecristo, who loved Italian and German generals during World War II and wrote an epic novel called “The Amazons”; Max Mirebalais, the ceaseless plagiarist who sought to combine Nazism and negritude: the heinousness of their political philosophy is the only thing that distinguishes them from any writer, anywhere, at any time. Moreover, literature, Bola#241;o writes, “is a surreptitious form of violence, a passport to respectability, and can, in certain young and sensitive nations, disguise the social climber’s origins.”换言之,他们是作家。如果用“文体诗”取代“法西斯”,这些虚构人物的生命轨迹就和波拉尼奥熟悉的那些真实生活中忙碌的作家们没什么两样。然而在《智利之夜》中,波拉尼奥剖析出虚伪和坏的信仰是易变而残忍的(主角是一个道德败坏、与军政府合作的神父),而在这里,他心中作家的一面让他情不自禁地去浓墨重、栩栩如生地详尽描写这些失落的灵魂与他们的可笑行为;而且他似乎无法彻底否定他们。作为一个旅伴,他或许太了解如何在破损的书页上营造幻想的世界,以此抵御真实世界坚固不移的价值观。想象中的人物埃内斯托·佩雷斯·马松(Ernesto Pérez Masón)努力创作他的中篇小说,称之为“一出性幻想,也是激烈的反美狂想,主角是艾森豪威尔将军与巴顿将军”;神秘的美女达妮埃拉·德·蒙特克里斯托(Daniela de Montecristo)热爱“二战”期间的意大利和德国将军们,写了一部名叫《亚马孙人》的史诗小说;不知疲倦的剽窃者马克斯·米雷巴莱斯(Max Mirebalais)想把纳粹和黑人传统文化自豪感结合起来。这些人信奉凶残的政治哲学,这是他们与其他任何时代、任何地点的作家们之间的唯一区别。波拉尼奥写道,文学“是暴力的一种隐秘形式,是通往名望的通行,在某些年轻而敏感的国度,可以掩盖不择手段挤进上流社会者的出身”。Who said literature has no real power to affect history? Not Bola#241;o — for him, literature is an unnervingly protean, amoral force with uncanny powers of self-invention, self-justification and self-mythification. The mythmakers, he suggests, certainly do matter. If Hitler had won, for instance, the not entirely absurd stories in this encyclopedia would be the prevailing stories of the culture. Is Nazi poetry an oxymoron? Not a bit of it, posits Bola#241;o. On the contrary, it’s all too possible.谁说文学对历史没有影响力?波拉尼奥肯定不这么认为——对于他来说,文学令人不安地变化多端,是一种无关道德的力量,有着自我创造、自我辩解和自我神化的神秘能力。他认为,编纂神话的人确实非常重要。比如说,如果希特勒胜利了,这本百科全书中并非完全荒诞的故事会成为文学史上盛行的故事。“纳粹诗歌”是一种矛盾修辞吗?波拉尼奥认为,绝对不是。相反,它是非常有可能的。 /201407/308830。
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