经济学人:热带疾病 (01)

Malaria killed 435,000 people last year, most of them in Africa.

去年435,000人死于疟疾,其中大部分在非洲。

The parasite that causes the illness is carried by females of some, but not all, species of mosquitoes of the genus Anopheles.

一些,并非所有,按蚊属雌性疟蚊都携带致病的寄生虫。

An insect becomes infected by biting an infected human being. Over the course of ten to 12 days, the parasites then multiply inside her.

当一只昆虫叮咬了被感染人群后,这只昆虫会被感染。在10 到12天内,寄生虫迅速在她的体内繁殖。

Once this has happened she transmits them with her bite.

一旦繁殖,她就会通过叮咬传播这些寄生虫。

The threat posed by an individual mosquito thus depends on its species, sex and age.

一只蚊子所造成的威胁取决于它的种类、性别和年龄。

Knowing these for lots of local insects gives a better idea of where, when and how to intervene in a particular place.

知道本地昆虫的这些信息可以更好的了解在哪、何时以及如何对某个特定地点进行干预。

If the locals are, for example, of a species that prefers to bite people inside houses,

例如,如果本地的一种种类喜欢叮咬房子里的人,

or to rest indoors after feeding, fumigating household interiors is the best approach.

或是喜欢在吃饱后在室内休息,那么对房屋内部进行消毒是最好的方法。

If not, it may be better to locate and disrupt breeding sites, using aerial spraying.

如果不是,那么最好是利用飞机喷雾对它们的繁殖点进行定位和破坏。

Sex is easy to determine. Males have bushy mouths—in essence, beards. Females do not.

性别很容易进行确定。雄性嘴部(其实是胡须)浓密。雌性则不是。

Determining species and age, though, is slow and laborious. DNA must be sequenced. Bodies must be dissected under microscopes.

虽然确定种类、年龄慢且费劲。DNA必须要进行排序。必须在显微镜下对尸体进行解剖。

Chemical analyses must be performed. Laboratories in Britain and Tanzania are therefore testing an alternative—infrared spectroscopy.

必须由化学分析师执行。因此英国和坦桑尼亚的实验室对一种替换方法—红外光谱法,进行测验。

Mario González-Jiménez, a chemist at the University of Glasgow, uses a diamond and a piece of steel that act as a hammer and anvil,

格拉斯哥大学化学家Mario González-Jiménez使用一颗钻石和一块钢充当锤子和铁砧

crushing the mosquito to be analysed. The infrared light is then provided by a laser.

压碎需要被分析的蚊子。然后用激光提供红外光。

With the insect duly splattered across one facet of the diamond, this laser is shone through the crystal onto it.

随着钻石的一面砸过这只昆虫,这束激光射过这面晶体。

The light reflected back out of the crystal by the insect's remains is run through a spectroscope for analysis.

通过昆虫尸体反射出的钻石光线穿过分光镜。

Part of the incident light will have been absorbed by various chemicals in the mosquito—

部分入射光将被蚊子中的各种化学物质吸收—

particularly chitin (a structural carbohydrate), proteins and lipids in the animal's cuticle.

尤其是几丁质(一种结构性碳水化合物)、蛋白质以及动物外皮的脂肪。

This absorption shows up in the reflected light's spectrum as an absence of certain frequencies.

这种出现在反射光光谱中的吸收显现的是某种频率的缺失。

These absences are called Fraunhofer lines, after the German physicist who discovered them two centuries ago.

这些缺失的频率被称为夫琅和费谱线,200年前,德国物理学家发现了它们。

Particular molecules create particular patterns of Fraunhofer lines,

随着消失的光能被吸收,也驱动了特定分子中的原子键振动,

as the missing light energy has been absorbed to drive the vibrations of atomic bonds within those molecules.

那些分子就可以创造出某些模式的夫琅和费谱线。

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