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英语煎蛋小学堂视频百科99:食腐动物为何没被毒死(MP3+中英双语)

cocotang 于2015-05-03发布 l 已有人浏览
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英语视频:煎蛋小学堂99:食腐动物为何没被毒死,以幽默诙谐的方式为你解答那些那些你意想不到的科学小知识,含有中英双语字幕视频,mp3下载。
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When a creature croaks,its natural defenses fail and tiny decomposers start digging in within just five minutes.To deter bigger carnivores in search of a meal,some feasting microbes produce toxins like anthrax and botulinum,tiny doses of which are fatal to much of the animal kingdom.Yet many scavengers get shoulder deep in deed meat without seeming to suffer and we're just beginning to understand how they do it.

当生物死去 躯体防御瓦解,五分钟后微生物就会开始分解尸体,为了防止大型动物跟它们抢食,一此微生物会释放毒素 诸如炭疽和肉毒菌,剂量虽小 但对许多动物而言却是致命的,但许多食腐动物食用这种毒肉后却安然无恙,我们来了解一下其中的奥秘,

Quality control is one of their earliest lines of defense.Wolves and foxes have been known to pass up diseased reindeer carasses in favor of prey killed by other predators,although it's not yet clear how they can tell the difference.And,despite their reputation,spooted hyenas prefer to dine on fresh meat,minimizing their contact with microbes.

质量控制是它们的初始防御线之一,我们知道 狼和狐狸会避开,其他捕杀的患病的驯鹿肉,不过它们是如何判断的 我们还不了解,且不论斑鼠狗的恶名,它们喜欢食用鲜肉 尽量避免与微生物打交道.

But sometimes,severly rotten flesh is the only item on the menu.And some scavengers,such as burying beetles and vultures.actually seek out putrid carrion because it's easier to detect,dig into,and defend.To combat the microorganisms in these meals,the beetles smear carcasses with antimicrobial slime before feeding.

但是有时 动物们只能找到严重腐烂的尸体,埋葬虫和秃鹰等良腐动物,会特意寻找腐肉,因为腐肉好找,易食,没人抢,为了斗赢腐肉里的微生物,曱虫在食用腐肉前会在上面涂上一层抗菌粘液.

Other scavengers prefer an after-dinner antibiotic.Bearded vultures assault microbes with stomach acid that's ten times more acidic than our own,and strong enough to corrode steel.But some tenacious pathogens,including the ones  that cause botulism and tetanus,make it through this caustic cauldron and thrive in the intestines beyond.

有些食腐动物则选择饱食后再服反腐抗生素,秃鹰用胃酸来对付微生物,它们的胃酸酸度是人类的十倍,浓度高到足以腐蚀钢铁,但是一些顽强的病原体,包括那种导致肉毒和破伤风的病原体,它可以活着通过秃鹰强腐蚀胃液,并在肠道另一端繁衍生息.

We're not sure how vultures survive their first few toxic exposures,but we know that with each encouter,their immune systems churn out more and more antibodies,building resistance to the toxins.Socializing can also give scavengers an immune boost.Hyenas and lions,for instance,likely pass small doses of germs around as they groom,eat,and compete with each other,which may help build up group-wide immunity to toxins like anthrax.

我们也不清楚秃鹰一开始是如何熬过毒素活下来的,但我们知道在经此磨难后,秃鹰的免疫系统开始大量分泌抗体,抵抗毒素,社交也有助于食腐动物提高免疫力,例如 土狼和狮子,会在舔毛和进食的时候摄入少量病菌,并且互相竞争,这可以让整个种群获得对抗病毒的免疫力 如炭疽,

Similarly,we humans have establishe our herd immunity through controlled exposure to diseases like meningitis and smallpox-we call it vaccination.But we have yet to beat botulism or anthrax,so perhaps we can scavenge some of these scavengers' tricks-after all,we have more in common with them than we may like to admit.

同样的 我们人类也通过接触微量病毒,建立起集体免疫力 如脑膜炎和天花,我们称之为疫苗接种,但是我们无法抵抗肉毒和炭疽,或许我们可以向这些食腐动物学习一下,不管我们承认与否 我们与它们确实很相像.

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