首页 >> 新闻 >> 正文

长沙/市星沙治疗肛瘘肛裂哪家医院最好的美生活星沙患者早泄

2018年05月23日 03:35:37来源:天涯互动

Science and Technology Avian malaria and climate change Bite the birds科技 禽虐与气候变化 鸟类受害Malaria among birds is becoming more prevalent鸟类中的疟疾感染越来越多MOSQUITOES, which carry malaria parasites, like the warm and wet conditions that are expected to become more common with climate change.携带疟原虫的蚊子喜欢温暖潮湿的环境,由于气候变化的影响这种环境可能会越来越普遍。This has led many to reason that malarial infections will increase.因此很多人推论,疟疾感染将会增加。Yet studies run into the unreliability of modelling future climatic effects and sometimes ignore changes in land use and health care.但是很多研究遇到了未来气候效应模型不可靠的问题,而且有时忽视了土地使用和健康保健方面的变化。However, a new analysis of the sp of avian malaria shows that for the birds, at least, there is a real worry.然而,一项新的对禽虐传播的分析显示,至少对于鸟类而言,真正令人担忧的状况已经出现。Laszlo Garamszegi, of the Do?ana Biological Station in Spain, studied patterns of malarial infections in birds to avoid confounding human factors in determining the epidemiology of a closely related parasite.在对一种有密切关系的寄生虫进行流行病学鉴定时,为避免混入人为因素,西班牙多尼亚纳生物站的喇撒?噶母赛棘研究了在鸟类中疟疾感染的模式。He looked at 43 previous studies that had carefully screened 3,000 bird species for malaria in different locations over the past 70 years.他察看了以前的43份研究。这些研究仔细鉴别了过去70年来在不同地区的3000中鸟类感染疟疾的情况。He found that an increase in global temperatures of 1°C was accompanied by a two-to threefold increase in the average prevalence of malaria in birds.他发现,全球气温每增加1°C,鸟类平均疟疾患病率随之增加两到三倍。The most dramatic increases took place during the past 20 years.最急剧地增加是发生在过去的20年间。Dr Garamszegis work, published in Global Change Biology, found that the house sparrow (Passer domesticus) showed a malaria prevalence that was less than 10% before 1990 when worldwide temperatures were cooler, but in recent years nearly 30% were infected.噶母赛棘士的论文发表在《全球变化生物学》杂志上,他发现,家雀(Passer domesticus)的疟疾患病率在1990年以前不到10%,那时全球气候比较凉爽,但是在最近的一些年里几乎30%被感染。The great tit (Parus major) presented a similarly worrying increase, with less than 3% infected with malaria before 1995 but closer to 15% in recent studies.大山雀(Parus major)的患病率有类似令人担忧的增加,1995年之前不到3%,而最近接近15%。The blackcap (Sylvia atricapilla), a migrant bird common in Europe that breeds in gardens, once had virtually no avian malaria but a study in 1999 showed nearly 4% had the disease.黑头莺在欧洲一种常见的候鸟,它们生活在很多公园里,实际上它们曾经并没有禽虐感染,但是1999年的一项研究显示,几乎4%的黑头莺感染了这种疾病。The effects of warming on avian malaria were not universal. Birds in Asia, North America and South America suffered much less change in their levels of infection during warm years than did birds dwelling in Africa and Europe.气候变暖对禽虐的影响并不普遍。亚洲、北美和南美的鸟类,在气候变暖的若干年里,其感染率的变化较小,而生活在非洲和欧洲的鸟类则受影响较大。Such trends may not have any relevance to the malaria parasites that infect humans.这种趋势与感染人类的疟原虫可能没有任何关系。But avian malaria is aly ravaging the native birds of Hawaii and it is now wreaking havoc in New Zealand, says Dr Garamszegi.但是禽虐已经毁掉了夏威夷的本地鸟类,它目前在新西兰正造成着巨大的破坏,噶母赛棘士说。Human beings may be able to mitigate the sp of malaria, but birds will need the help of conservationists if some species are to survive.人类也许已经使疟疾的传播减缓,但是如果某些鸟类要幸存下来,就需要环境保护主义者们的帮助。 /201212/214489。

  • Scientists say they have reconstructed around half of the genome of the woolly mammoth, a species that became extinct at the end of the last Ice Age some 11,000 years ago.The sequence comes from DNA in hair snipped from two woolly mammoths whose bodies have been preserved in Siberian permafrost for tens of thousands of years. Important gaps in the picture remain, but even so, enough data is there to make a comparison between the woolly mammoth and its closest living relative, the elephant, they said.科学家们说他们已经对长毛象的半数基因组重新进行组合。长毛象在冰河世纪末期,也就是一万一千年以前就开始灭绝。基因组序来源于两只长毛象身上剪下的毛发。这两只长毛象遗体保存在西伯利亚永久冻土地带已有数万年。 科学家们说,基因组序里有重要的遗漏,即使是如此,仍有足够的数据将长毛象和其近亲大象进行对比。The two species are so similar that their DNA differs by just 0.6 percent, or about half the differences between humans and chimps. The team made a first breakthrough last year by using mammoth hair to extract mitochondrial DNA, genetic material that is inherited from the female line. The hair technique marks a giants step forward compared to the previous method, which consisted of teasing DNA out of the remains of frozen bone marrow.长毛象和大象很相似,它们基因的差别只有百分之0.6,这个数字差不多是人类与黑猩猩基因差别的一半。 在去年这个团队通过从长毛象毛发中提取线粒状基因研究获得了第一次突破。这种线粒状基因物质是从雌性链体上遗传下来的。 相比之前的方法,这种从毛发里提取基因的技术标志着一大进步。这一技术包括梳理重组冰冻的长毛象骨头里的DNA。Rebuilding the mammoths genetic code has fired speculation that scientists may one day revive this species and other Ice Age beasts on the lines of the Hollywood movie ;Jurassic Park.; Researchers say it should one day be theoretically possible to replicate a mammoth by taking the elephants genome, stripping out the code that is specific to the elephant and replacing it with code specific to the mammoth.重组长毛象的基因密码引发了一种猜测,科学家可能在某一天使长毛象和其他冰河时代的动物苏醒,就像上映的电影“侏罗纪公园” 那样。研究者还说,理论上可以通过提取大象的基因,剥离特定的大象基因密码,注入特定的长毛象基因密码来复制长毛象,这一天有可能会到来。201206/186905。
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