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2019年12月13日 16:57:22

What makes the human brain so special? Actually, it mightnot be that special after all.所以说是什么让人类的大脑如此特别?实际上,这或许根本就不特别。In , Dr. Suzana Herculano Houzel and her colleagues showed that the human brain has thesame density of nerve cells as other primates. Comparing humans to smaller primates, she claimsthat our brain is no bigger than it should be for our body size. Still, given the distinctive way thatprimate brains scale with size, we may have the most brain cells of any mammal.在年,苏珊娜·埃尔库拉诺·乌泽尔士和她的同事们展示了人类大脑的神经细胞密度和其它的灵长类动物一样。与其它较小的灵长类动物相比,苏珊娜士称我们的大脑与我们自身体型相比并不算大。但考虑到灵长类动物大脑尺寸比例的独特方式,人类拥有所有哺乳动物中最多的脑细胞。That being said, gorillas can grow to be three times our size, but still have much smaller brains thanours.话虽如此,大猩猩能长到我们体型的三倍,但它们的大脑仍然比我们小得多。Brain cells need more energy than most body cells. Although the brain is less than 2 percent of themass of the human body, it consumes 20 percent of our resting metabolic energy. Gorillas haveto spend more than eight hours every day eating to get enough calories to support their bigbody, and they simply cant afford a bigger brain.脑细胞比其它身体细胞需要更多的能量。虽然大脑所占人体的比重小于2%,但它却消耗我们静止时代谢能的20%。为了给庞大的身躯提供足够的能量,大猩猩每天要花费超过8小时的时间进食,因此它们无法负担更大的大脑。So, then, how did human ancestors overcome this limitation? Beginning with homo erectus, abouttwo million years ago, our ancestors couldnt have afforded the metabolic cost of their increasinglylarge brains if they ate raw food like gorillas do.所以,人类的祖先又是如何突破限制的?从直立的人类开始,大约两百万年前,随着大脑越来越大,如果人类的祖先还像大猩猩那样进食生的食物,那么他们将无法给大脑提供足够的代谢值。Primatologist Richard Wrangham thinks that the invention of cooking with fire is what made thisgrowth in brain size possible. Cooked food is easier to digest and yields more calories. Cooking mayhave made the human brain possible, and freed us from having to spend all day eating.灵长类动物学家理查德·兰厄姆认为发明用火烹饪,使得大脑生长变大成为可能。烹煮的食物更容易消化并且能产生更多的热量。烹饪或许促进了人脑的形成,并将人类从整日进食的境况中解放出来。 /201503/363315郴州最好治疗前列腺炎医院永兴县包皮手术怎么样The battle between Michigans public universities and state lawmakers over funding has ramped up in recent weeks.Both Eastern Michigan University and Oakland University have busted state-imposed tuition caps, deciding that the states ;reward; for not raising tuition just wasnt worth it.The universities raised their tuition for the upcoming school year by 7.8% and 8.48% respectively.David Jesse of the Detroit Free Press explains that since 2012, the state has placed a cap on how much universities can increase their tuition in a given year. That cap fluctuates year to year, but this year was 3.2%.Staying under the cap means the schools will receive some extra ;performance funding; from the state in addition to the normal base funding.;You stay under it, you get all your performance funding. You dont stay under it, wave goodbye,; he says.The reason Eastern and Oakland decided to turn down that offer this year comes down to basic arithmetic, according to Jesse.He says by breaking the tuition cap, these universities will see approximately ten times the amount of extra funding than if they had accepted the states performance incentive.This decision has made some politicians unhappy, but Jesse says its not one the schools have made lightly. The way they see it, they need more money in order to implement the plans and programs they need to remain competitive. Jesse says the universities are acting perfectly within their rights.;Our constitution says that the universities are autonomous and they can do what they want,; he says. ;TheLegislature cant tell them what to do. But they can tie all sorts of things to finding. They can reward or punish with funding.;Jesse says although the tuition increase will give universities more flexibility, it also puts more pressure on students and their parents to meet tuition costs.David Jesse tells us more about the tuition decision and what impact it could have in our conversation above.201507/385942听力参考文本(文本与听力不全一致,敬请谅解):Two years after Toledos water supply was shut down by so-called blue-green algae, people are still worried about the safety of the citys drinking water.Toxins called microcystins are sometimes produced by certain freshwater cyanobacteria blooms. Those blooms are more likely under certain conditions, and every summer Toledo is on the watch for an increase.Tom Henry is a columnist with the Toledo Blade and has extensively covered this problem in Lake Erie.Henry told us that the water quality wasnt too bad this year. He said this years bloom was “toxic in some areas, but still considered fairly mild in terms of volume and biomass.”Despite that and the myriad measures the city is taking to ensure their waters safety, he told us many Toledoans still dont feel great about using their tap water.“The late mayor Michael Collins, we talked a lot about this during the water crisis, and he told me afterward that it was a crisis of confidence. He said people lost faith, lost confidence in us as they should have because we let them down,” Henry said.We also spoke with activist and former Ohio Green Party gubernatorial candidate Anita Rios, who lived through the water shutdown in Toledo two years ago.“Just consider what your day would be like if that happened. We couldnt make coffee, we couldnt even wash our face or brush our teeth,” she said.She told us that the water is now safe to drink, but it has a definite chlorine taste to it.“Its an unpleasant thing,” she said, “but its certainly better than being poisoned.”Both Rios and Henry told us there are similarities between the water crisis in Toledo and that in Flint.“The parallels between Toledo and Flint are there in terms of missed warning signs,” Henry told us.“There are huge similarities between Toledo and Flint,” Rios said. “Of course were both rust belt towns that I feel are largely forgotten, and I think that for us, the ordinary citizens, the important thing is that we need to push for some of these changes, because its not going to get better without our voice.”201610/470133郴州市治疗膀胱炎多少钱

郴州不育男性郴州市第一人民医院南院治疗包皮包茎多少钱A civilian helicopter plunged into the waters of Hawaiis Pearl Harbor on Thursday.周四,一架民用直升机坠毁在夏威夷珍珠港水域。The crash resulted in its five passengers being taken to hospital, including a teenage boy who was in a critical condition.事故导致五名乘客被送往医院,其中包括一名伤势危急的十几岁男孩。Military and local emergency officials said the crash occurred near the National Park Service Pearl Harbor visitor center around 10:30 a.m. local time.军队和地方急救官员表示,事故发生在当地时间上午十点半,位于珍珠港国家公园游客中心附近。Honolulu Emergency Services Department spokeswoman Shayne Enright said there were indications that bystanders jumped into the waters near the USS Arizona Memorial to rescue the individuals from the crashed helicopter.火奴鲁鲁急救务部门发言人肖恩称,迹象表明有旁观者跳入亚利桑那纪念馆附近水域,营救坠机人员。译文属。201602/427163Sublimation on this moment of science.今天我们的节目要讲的是:升华现象。Pop quiz, everybody put away your books, and keep your eyeson your own radio.各位,请放下你们手中的书本,专心听收音机,我们来做一个突击测验。You fill the ice tray up to the rim and put it in the freezer.用水将冰格填得满满的,漫过冰格的边缘,然后再将冰格放到冰箱的制冷室里,Theice that results will be最后结成的冰会:at the rim over the rim under the rim.刚好齐边 边缘以上 边缘以下Answer? It depends.是要看情况而定。I know, you hate that.我明白,你们不喜欢这样的。But it does depend-it depends on how long you wait before checking onthe ice again.但是,实际情况确实如此—取决于你要过多长时间去查看。My guess would be that most folks chose answer b: over the rim.我猜,很多人都会选择b边缘以上。That is correct, ifyou checked on the ice trays after only a couple hours.如果你在放入制冷室仅两个小时之后去查看的话,这个就是正确的。Thats because water expands when itturns into ice, as you know if you ever put a soda bottle in the freezer and came back to find it exploded all over the fish sticks.这是因为水在变成冰的时候会膨胀。就像大家所知道的,如果将一瓶汽水放在制冷室中,回头去看的时候会发现,汽水已经炸开了,整个制冷室中到处都是汽水。But if you were to leave the ice tray untouched for a couple of months, you might find the ice tobe under the rim, or lower than the water was.但是,如果你将冰格放在制冷室中,好几个月都不动它的话,你会发现,冰在边缘以下,或是低于你之前装的水的高度。Huh? Didnt we just say water expands when it freezes? Initially, yes.哈?我们刚刚不是才说了水在变成冰的时候会膨胀吗?最开始的时候,会。But frozen water can dosomething else as well: it can sublimate.但是冷冻之后的水也会有其他的变化:升华。To sublimate is to go from one state to another without passing through the usual intermediary state.升华也就是物质不经中间状态直接从一个状态转变成另一个状态。By adding heat, ice can be melted into liquid water, which can be evaporated.通过加热,冰可以化成液态水,液态水可以被蒸发为水蒸气。Thats three states:solid, liquid, gas.这是三个状态:固态,液态,气态。But given enough time, ice can also turn into a gas without melting first!但是,如果时间足够的话,冰可以在不被融化的情况下转变为气态。When your ice cubes seem to have shrunk, its because they are sublimating:如果你的冰“缩水”了,那是因为被升华了:the frozen water is slowlyevaporating off the cubes, without ever actually melting.在没有被融化的情况下,固态水以非常缓慢的速度在蒸发着。Will this work in any freezer? Next time.这种现象在任何的制冷器中都会出现吗?下次再谈。 201410/338529郴州治皮肤科郴州人民中妇幼保健医院泌尿外科

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