时差N小时 昆虫是如何对抗细菌和寄生虫的?(在线收听) |
Imagine that you're an insect, and that you've fallen ill because some bacteria or parasites have invaded your body. If you want to make it to a ripe old bug age, your body will need to fight off these invaders. 想象一下你是一只昆虫,由于细菌或者寄生虫的入侵,你生病了。如果你想保持跟过去一样的体质,那么你就要跟这些入侵者做斗争了。 The problem is that if you're a bug, your life span may be only a few days long. This means that unlike humans, you simply don't have the time to lounge around in bed, watching TV and waiting for your body to figure out how to fight off each disease it encounters. 问题在于,假如你是一只小虫,你的生命周期可能仅有几天。这意味着你不能像人类一样有足够的时间在床上躺着,看看电视,然后等着观察身体是如何抵御这些入侵的疾病。 Still, there's no reason for your insect self to panic. Evolution has provided you with what scientists call innate immunity, which you inherit from your parents. Innate immunity means that your bug body has the capability to instantly recognize and destroy many dangerous intruders. 但是作为一只小虫,你也没必要为此恐慌或担忧。大自然的进化过程已使你获得科学家们所谓的“先天免疫”能力,你从父母那里遗传而来的能力。先天免疫能帮助昆虫的身体在最短时间内发现并且摧毁这些危险的入侵者们。 In your bug body there is a fluid called hemolymph, which is equivalent to human blood. If you're injured, components in the hemolymph interact with specialized cells in your immune system to clot and form a scab that seals off your wound and prevents infection. The hemolymph also contains proteins that are ready to kill invaders like bacteria or fungi. However, some invaders, like tiny parasitic insects, may be too large for the proteins to handle. 在昆虫身体里有一种被称为“血淋巴”的液体,它与人类的血液发挥着相同的作用。当你受伤时,血淋巴里的某种成分便与免疫系统中某些特殊细胞进行相互作用,从而使伤口凝结并结痂,保护伤口不受外界环境干扰以避免感染。而且,在血淋巴中还包含某些蛋白质,它能有效地杀灭这些入侵者,比如细菌或真菌。当然,像小寄生昆虫这样的入侵者,由于它们的体积较大,血淋巴里的蛋白质的杀灭能力对此还是望尘莫及。 In this case, your body encapsulates the invader and walls it off from the rest of the body. The encapsulated invader then stays inside you for the rest of your natural bug life, or until you fly into a windshield, whichever comes first. 在这种情况下,你的身体中封装了入侵者,且与身体其他部分隔离开来。在你短暂的昆虫生涯中,这个被封装的小小入侵者会一直保留在你体内,或者某天你不小心撞上挡风玻璃,这个封装的过程才会提前宣告结束。 |
原文地址:http://www.tingroom.com/lesson/scnxs/529430.html |