科学美国人60秒 SSS 'Necrobiome' Reveals a Corpse's Time of Death
时间：2018-12-02 作者：英语课 分类：2016年Scientific American(十二)月
Tens of trillions of microbes call our living bodies home. But when we die? "The first thing that happens is basically ecosystem 1 collapse—where you have a tremendous loss of diversity." Nathan Lents, a molecular 2 biologist at John Jay College in New York. "And then it bottoms out and starts to get rich again."
That microbial phoenix 3, rising from our extinguished mortal coils, is called the "necrobiome." Lents and his team tracked the necrobiome, by swabbing the ears and noses of 21 cadavers 4 at a body farm in Tennessee. It's a sort of outdoor lab for forensic 5 scientists, where bodies are left to the elements to decompose 6.
They tracked the genetic 7 signatures of that microbial community as it waned 8 and waxed after death. And they used that data to build an algorithm that could pinpoint 9 a corpse 10's time of death, to an accuracy of just two summertime days. "And that held out for up to six to seven weeks. And that's way better than entomology can tell you." Entomology being the study of the insects that colonize 11 a corpse. "Entomology's ok for giving you upper and lower limits within five to seven days, but beyond that, entomology's not helpful."
The study is in the journal PLOS ONE. [Hunter R. Johnson et al, A Machine Learning Approach for Using the Postmortem Skin Microbiome to Estimate the Postmortem Interval]
The method isn't quite ready for primetime. There's still a lot of 'biological noise' in the system. "We're talking about living things here. Well.. living and dead things." But as with any machine learning, more info will help it see beyond the noise. "It will forever learn. So the more data we pump into this system, the better it will get." Ultimately, Lents says, the algorithm will have to be smart enough to hold up in a court of law, when it could determine the fate of someone accused of turning someone into a corpse.
—Christopher Intagliata
[The above text is a transcript 12 of this podcast.]
- This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
- We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。
- The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
- For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。
- The airline rose like a phoenix from the ashes.这家航空公司又起死回生了。
- The phoenix worship of China is fetish worship not totem adoration.中国凤崇拜是灵物崇拜而非图腾崇拜。
- Human cadavers were the only known source of hGH, and demand was intense. 人类尸体是hGH已知的惟一来源，而且需求广泛。 来自英汉非文学 - 生命科学 - 口蹄疫疯牛病
- Will there be enough cadavers for each group this term? 这个学期每一个组都有足够的尸体吗？ 来自电影对白
- The report included his interpretation of the forensic evidence.该报告包括他对法庭证据的诠释。
- The judge concluded the proceeding on 10:30 Am after one hour of forensic debate.经过近一个小时的法庭辩论后，法官于10时30分宣布休庭。
- The eggs began to decompose after a day in the sun.鸡蛋在太阳下放了一天后开始变坏。
- Most animals decompose very quickly after death.大多数动物死后很快腐烂。
- It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
- Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
- However,my enthusiasm waned.The time I spent at exercises gradually diminished. 然而，我的热情减退了。我在做操上花的时间逐渐减少了。 来自《用法词典》
- The bicycle craze has waned. 自行车热已冷下去了。 来自《现代汉英综合大词典》
- It is difficult to pinpoint when water problems of the modern age began.很难准确地指出，现代用水的问题是什么时候出现的。
- I could pinpoint his precise location on a map.我能在地图上指明他的准确位置。
- What she saw was just an unfeeling corpse.她见到的只是一具全无感觉的尸体。
- The corpse was preserved from decay by embalming.尸体用香料涂抹以防腐烂。
- Around 700 Arabs began to colonize East Africa.公元700年阿拉伯人开始把东非变为殖民地。
- Japan used to colonize many countries in Asia.日本曾经殖民过许多亚洲国家。
- A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
- They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。