The Mini-Lecture of TEM81. CamelA camel can travel hundreds of miles, over several days, without stopping to drink.On todays Moment of Science, well learn how camels survive the dry desert.Lets start with the hump. Contrary to what you might have heard, camels do not store extra water here. The hump stores fat, providing energy for their long, desert trek. This fat, however, can help keep a camel from getting thirsty. As the fat is burned, water is produced as one of the byproducts. This extra water enters the camels bloodstream to add to its water supply.Camels conserve water by not sweating as much as we do. A camels metabolism lowers at night, making its body temperature much lower than a humans. Because we sweat to cool ourselves off, starting with a lower body temperature means less need to sweat. Camels are also covered with heavy fur which keeps the daytime heat out. Because its so good at keeping its cool, a camel can travel a long way without sweating very much.Camels are also good at maintaining their blood volume. Once we humans lose about twelve percent of our bodys water, our blood becomes too thick to work properly. A camels blood, however, stays more or less consistent, allowing the camel to lose up to twenty-five percent of its weight by dehydration.Another thing that helps a camel conserve water is its nasal passages. When we exhale, we loose a lot of water vapor, as any fogged up car window will prove. Camels have extra dry nasal passages which actually recondense the water out of each breath, allowing much less to escape.As you can see, there is no single explanation for a camels desert survival abilities. Instead, a camel draws on a whole range of adaptations.译文：骆驼可以行走数百英里，并在几天之内也不用喝水。在今天的科学一刻中，我们将会学习骆驼是怎样在干燥的沙漠中生存的。我们先从驼峰说起，和你所听说的不一样的是，骆驼并没有储存多余的水在这里。驼峰积聚着脂肪，为它们长距离的沙漠旅行提供能量。然而就是这些脂肪，可以帮助骆驼止渴。水就是这些脂肪燃烧所产生的副产物之一。这些额外的水进入骆驼的血液，增加其水分的供应。骆驼不像我们那样出汗，这样也可以储存水分。骆驼的新陈代谢到晚上就会降低，让它的体温低于人类。出汗可以冷却我们自己，因此如果体温较低的话，对汗水的需求也会比较少。骆驼同样覆盖着厚重的皮毛，这些皮毛可以防止白天的热量进入体内。正因为骆驼如此擅长保持其身体的冷却，所以它可以走很长时间，却不会流很多汗。骆驼同样也很擅长保持它们的血容量。我们人类一旦流失了身体百分之十二的水分，血液就会变得太浓稠以至于不能正常工作。可是骆驼的血液，总是可以坚持到让其脱水到其重量的百分之二十五。另一个有助于骆驼储存水的东西就是鼻腔。当我们呼气的时候，我们会流失许多水蒸汽，被雾气模糊的车窗可以证明这一点。骆驼有额外的干燥鼻腔，可以凝聚每次呼吸的水分，让水分的蒸发的变少。就如你所见，没有关于骆驼沙漠生存能力的单一解释。相反地，骆驼有一系列的适应能力。2. Oceans Most Wanted 外来物种入侵伴随着人们的经济活动和国际交往，一些物种由原生存地借助于人为作用或其他途径移居到另一个新的生存环境并在新的栖息地繁殖并建立稳定种群，这些物种被称为外来物种。我国是世界上海洋生物多样性最丰富的国家之一，被国际保护组织誉为“生物多样性大国”和“生物多样性全球热点地区” 。但随着我国海洋运输事业的发展、国际贸易的日趋频繁、海水养殖品种的传播和移殖，我国海洋外来物种数量越来越多，对我国的海洋生物多样性和海洋生态系统安全带来了严重影响。以养殖生物为例，鲍、牡蛎、扇贝、对虾、鱼类、藻类等大量从国外引入亲体，甚至新物种，在养殖过程中由于各种方式导致养殖对象进入自然海域，不仅与当地土著生物争夺生存空间、饵料，争夺生态位，并且传播疾病、与土著生物杂交导致遗传污染，降低土著生物的生存能力，导致土著生物自然群体降低，甚至濒于灭绝。 They might seem innocent and lovely in your (1)aquarium, but released into the wild, your plants and fish can knock aquatic ecosystems right out of balance. Todays invasive species: the (2)water hyacinth.Native to the Amazon basin, but considered an ornamental aquarium plant, the water hyacinth was introduced to Florida in 1884. By the mid-1950s, water hyacinths were clogging Floridas water ways and interfering with navigation, not to mention displacing the native species. Clean up took millions of dollars, and theyre still spreading on every continent except Antarctica.Guess how many of the species on the International Union for the Conservation of Natures list of the one-hundred worst (3)invasive species are the result of aquarium and ornamental releases?How many?A full third! You see, when it comes to aquarium animals and plants, were dealing with mature adults, and particularly hardy ones at that, since the weaker ones dont survive transport. So whenever theyre released into the environment, either intentionally or accidentally, theyre better able to establish themselves.Despite all this, until recently researchers have largely ignored the role of pet fish and aquarium plants when studying the spread of exotic and invasive species. Finally, its time for some guidelines(指导方针), especially ones that encourage the trade of less invasive and aggressive species, or the substitution of native and/or safer species that people could grow instead.译文：在你的水族箱里它们或许看起来很天真，很可爱。但是一旦被放生到野外，你的植物和鱼就会打破水生生态系统的平衡。今天的入侵物种是：水葫芦。水葫芦原产于亚马逊河流域，但作为一种观赏性水生植物，在 1884 年被引入佛罗里达州。到 20 世纪中期，水葫芦就造成了佛罗里达州水路的堵塞，干扰航运，更何况还取代了本地物种。尽管清理花费了数百万美元，但是它们仍然在除南极洲以外的各大洲蔓延。你猜猜在国际自然保护联盟的最严重的 100 个入侵物种名单里，有多少是因为水族箱和观赏性放生造成的？有多少呢？整整三分之一！你知道的在选取水族馆动植物品种时，我们一般选用已长大成熟的动植物，尤其是易养活的那类，因为其他那些相对脆弱的动植物在运输的路途上无法存活下来。因此不论他们何时被放生到外界，故意的或是无意的，它们都能够很好的适应生存。尽管如此，直到最近研究者们在研究外来入侵物种时都很大地忽略了宠物鱼和水生植物所扮演的角色。最后，是时候该制定一些指导方针了，特别是针对减少入侵和侵略物种交易的规定，或者取而代之种植一些本地的和更安全的物种。Notes:(1)aquarium kwrim n.水族馆；养鱼池；玻璃缸Visit an aquarium shop and watch how fish swim.参观一间水族店，观察鱼类如何游泳。(2)water hyacinth 水葫芦；凤眼兰；凤眼蓝(3)invasive inveisiv adj.侵略性的；攻击性的Now, what type of invasive lobular carcinoma is it?那么，是什么亚型的浸润性小叶癌呢？3. Cosmic Radiation 宇宙辐射上世纪早期，科学家发现一种神秘的辐射形式会破坏他们的实验。后来奥地利物理学家 Victor Hess 研究发现辐射可能来自天空。后来他多次坐热气球用各种仪器（包括测量放射电荷的验电器）收集资料。一次热气球旅行时，遇到日全食，他发现辐射的放射量维持不变，而推定辐射来自