四川 | 原创| 国内| 国际| 娱乐| 体育| 女性| 图片| 太阳鸟时评| 市州联播| 财经| 汽车| 房产| 旅游| 居家| 教育| 法制| 健康| 食品| 天府新区| 慢耍四川
您当前的位置:四川新闻  >  本网原创


2018年01月23日 13:36:45

福田区脱小腿毛多少钱Science and technology科学技术How dung beetles navigate蜣螂如何导航Stars in their eyes眼里有星辰An insect that steers by the Milky Way观天识途的昆虫THE number of animals that navigate by the stars is small.靠观察星辰行走的动物不多。Only some birds, a few seals and, of course, humans have the ability.仅仅有某些鸟类、海豹,当然人也有这个本事。It had been assumed that other creatures that might do this would need reasonably well-developed brains.过去人们设想其他具备这种能力的生物很可能拥有发达的大脑。That notion has now been proved wrong as the celestial-navigation club welcomes its latest member: the humble dung beetle.现在这种见解被推翻了,因为天文导航俱乐部迎来了自己最新的成员—不起眼的蜣螂。Life in the world of dung beetles is fiercely competitive.蜣螂在这个世界上过着你争我夺的生活。After rolling up a ball of highly nutritious dung, the beetle must race off with it or risk having the ball stolen by other beetles.蜣螂必须把自己团好的极富营养的粪球搬走,否则劳动成果会被其他的蜣螂偷走。Strength is important, but so too is the route taken.力量很重要,运输路线也不能轻视。The ideal tactic on the open plains where many dung beetles live is to move in a straight line.很多生活在广阔平原上的蜣螂采用走直路的理想策略。This is easy enough during the day, but at night—when the beetles are most active—it is more challenging.这在白天不难办到,然而晚上才是蜣螂最活跃的时间,此时走直路对它们来说就是挑战了。Previous work has shown that dung beetles can make use of the moon to help them navigate, yet some still set a straight course on moonless nights.以前人们发现蜣螂利用月亮导航,如果晚上没有月亮,也有蜣螂走直路。To find out how, a team working in South Africa led by Eric Warrant and Marie Dacke, of Lund University in Sweden, designed an intriguing experiment.为了找到蜣螂夜里能走直路的原因,Eric Warrant和Marie Dacke领导的瑞典隆德大学工作团在南非设计了一个有意思的试验。They made caps for 19 dung beetles.他们给19只蜣螂做了帽子。Ten wore caps made of cardboard to prevent them seeing the sky and, as a control, nine wore caps made of transparent plastic.10只蜣螂戴着薄纸板做的帽子,这样他们就看不到天空了。作为对比,其他9只蜣螂戴上了透明塑料制成的帽子。The beetles and their dung balls were then released in the centre of a circular arena made of flattened sand and enclosed by a featureless circular wall.这些蜣螂和它们的粪球都被放在了一个平铺着沙子圆形场地的中央,场地的围墙也没有什么特别之处。As the beetles rolled away under a moonless night sky they were filmed by infra-red cameras.在没有月亮的晚上,红外线摄影机记录蜣螂搬运粪球的活动。The team found that the beetles prevented from seeing the sky by their caps had path lengths that averaged 476.7cm, much longer than the average of 143.4cm travelled by the beetles wearing clear hats.试验人员发现被帽子遮挡了天空的蜣螂平均行走476.7cm,远远超出戴着透明帽子的蜣螂的平均路程143.4cm。As the beetles might have used other overhead landmarks, like trees,因为蜣螂可能使用位于高处的其他地标。a second arena was built with a high black wall and a small, dry moat around it.第二个场地是黑色高墙围起来的,This time the beetles—minus their hats—were timed to see how long it took them to roll their balls from the centre to the point where they could be heard falling into the moat.附近有一条干涸的壕沟—这次蜣螂没有戴帽子—实验人员要看看他们从场地中央滚粪球到跌入壕沟能用时多久。Under a full moon the beetles took an average of 21.4 seconds to reach the moat.满月之夜蜣螂抵达壕沟平均耗时21.4秒。On a moonless, starry night, their speed was somewhat reduced, but not significantly so.在繁星满天的无月之夜,它们的速度有所下降,但降得不多。However, under overcast conditions, when neither moonlight nor the stars were visible, the beetles took an average of 117.4 seconds.如果晚上阴天,看不到星星和月亮,蜣螂抵达目的地要平均耗时117.4秒。Curious as to what it was in the sky that the beetles were using to navigate, the team moved their arena inside the Johannesburg planetarium and reran their experiments.因为试验人员急于了解蜣螂到底利用天上的什么物体导航,他们到约翰内斯堡天文馆做室内实验。As they report in Current Biology, the beetles presented with a full starlit sky, including the Milky Way or just the Milky Way, took statistically the same amount of time to exit the arena.他们在《当代生物学》杂志上统计了蜣螂在繁星满天的夜空下走出场地用的时间在统计学上是相同的,Under a sky full of dim stars they were only a little slower.天上的星光不亮,它们要稍微慢一点。This, speculates Dr Warrant, is because they were still able to spot the cluster that forms the Milky Way.通过试验Warrant,士推测,这是因为蜣螂还能认出系形成的星团。When allowed to see only the 18 brightest stars or immersed in total darkness, the beetles took more than twice as long to exit the arena.如果暗夜里只有18颗最亮的星星,蜣螂离开场地的时间要高出两倍以上。The team now wonders how many other animals might be able to use the glowing strip of light created by the Milky Way to guide them.这个团队的工作人员现在想知道到底有多少动物可以利用系形成的发光带活动。 /201310/261132深圳人民医院打溶脂针多少钱Feifei:It seems you were an awful student.飞飞:看来你是个差生。Diarmuid:Well, its true I was never a swot.戴拉蒙德:嗯,这是真的,我从来就不是swot。Feifei:A what?飞飞:一个什么?Diarmuid:A swot. S.W.O.T. Swot.Can you guess what it means?戴拉蒙德:一个swot。你能猜出它的意思吗?Feifei:Well, since you say you were not a swot and you got very bad grades at school, I would say that a swot is a very good student.飞飞:嗯,既然你说你不是一个swot,而你在学校的成绩又非常糟糕,所以我猜swot代表的是非常好的学生。Diarmuid:Youre right.戴拉蒙德:完全正确。A swot is a student who spends all their time studying, or swotting.Swot指的是一个把所有的时间用于学习学生。Being a swot usually means that other students dont like you. Example成为这样的人通常意味着其他学生不会喜欢你。下面就是例子。A:Look at this old photo of our class at school.A:看这张在学校我们班级的老照片。B:Oh yes, theres Simon Studious. He was such a swot. I wonder whatever happened to him.B:哦,是的,这是好学生西蒙。他真是个学霸。我想知道他身上发生过什么。A:I heard he started his own software company; hes a multi-millionaire now.我听说他开了自己的软件公司,他现在可是个百万富翁。B:Oh. Wish Id worked a bit harder then.B:哦。真后悔当初我没好好用功。Diarmuid:But you dont have to be a student to use this word.戴拉蒙德:但你不必成为一个学生来使用这个词。We can use the verb form – to swot up – to mean learn more about anything.我们可以使用其动词形式—意思是刻苦攻读,意味着学习更多关于任何东西。Feifei:So I could say Im going to swot up on laptops because I want to buy a new computer.飞飞:所以我可以说我要研究笔记本电脑,因为我想买一台新电脑。Diarmuid:You certainly could.戴拉蒙德:你当然可以。 201309/258087深圳市人民医院治疗腋臭多少钱

深圳激光去脂肪多少钱深圳伊斯佑医疗美容门诊部激光点痣多少钱Science and technology科学技术Crowdfunding science集资科技Many a mickle makes a muckle积跬步致千里These days, anyone can be a scientific philanthropist眼下人人都是科技慈善家NECESSITY, so the proverb has it, is the mother of invention.有句谚语说得好:没有需求,就没有发明。And science is nothing if not inventive.科技失去了创新,就变得一文不值了。So, as conventional sources of money get harder to tap, some of sciences more creative minds are turning elsewhere.所以,当无法轻易获得传统的经济持时,一些有创造力的科研人员便开始寻求新的资金来源。Philanthropic sponsorship of science, particularly in the form of expensive pieces of kit such as large telescopes, or sponsorship for expeditions to far-off places, has been around for centuries.科技慈善资助已有几个世纪的历史,资助形式多为捐赠大型光学望远镜之类的昂贵仪器,或者是为偏远地区的探险提供赞助。But the internet now permits what might be thought of as microphilanthropy.不过在网络的帮助下,如今微慈善也成为可能。Through a technique called crowdfunding, in which members of the public donate small sums to projects they like the look of, the possibility of scientific philanthropy has been extended to those of more slender means.基于一种名为众基金的技术,公众可以给他们看重的项目捐赠小额资金,科技慈善事业已扩大到微薄资金来源。On October 4th, for example, Ethan Perlstein, a pharmacologist at Princeton University, launched a bid on a site called RocketHub to collect 25,000 to study the effect of drugs such as methamphetamine on the brain.例如,普林斯顿大学的药理学家伊桑?浦斯汀,10月4日就在一家名为火箭中心的网站公开招标,募集25000美元的资金用于研究甲基苯丙胺等药物对大脑疾病的疗效,He has until November 18th to raise the money.招标将截止于11月8日。Kristina Killgrove, an anthropologist at the University of West Florida, has aly raised over 12,000 on RocketHub to examine the DNA of Roman skeletons.克里斯蒂娜科尔戈薇是西佛罗里达大学的一名人类学家,她就通过火箭中心网站募集了12000美元用于自己对罗马骸骨的DNA检验。And on another crowdfunding site, Petridish, the California Academy of Sciences offered to name any new species of ant discovered during a conservation project in Madagascar after those who donate more than 5,000 to the enterprise.培养皿网是另一个融资网站,加州科学院就因为通过该网站获得了5000多美元的项目基金,他们完成了为马达加斯加保护项目中发现的蚂蚁新物种命名的工作。Although the crowdfunding of science is not raising the sorts of sums sometimes attracted by those with ideas for things like games, it has aly spawned a couple of specialised platforms of its own.尽管科技融资不再是只有类似的项目才能拿得到资金,但融资过程还是形成了自己的专业平台。Petridish is one.培养皿网就是一例。Another is called Microryza.Microyza也是一个代表网站。And academic institutions are starting to follow the lead taken by the CAS.学术机构都开始模仿加州科学院,募集资金。The University of California, San Francisco, has made a deal with a site called Indiegogo that will allow the universitys charitable status to make money donated via Indiegogo tax deductible.加利福尼亚大学旧金山分校与Indiegogo网站达成协议,提高了他们的会员慈善等级,可以使经网站募集的资金免税。It will launch the first such project later this month.这个月晚些时候将启动他们的第一个项目。Donors can expect no revenue if a crowdfunded science project is successful, of course.捐赠人肯定没想着融资的科学项目成功后他们会获得任何收入。But they can expect to be kept up to date with progress.但他们可以获悉实验的进度。Dr Perlstein has promised to upload all data from his experiments onto a website, for his sponsors to look at.浦斯汀士就承诺会把实验中的所有数据上传到网站,供捐赠人查阅。And even those who are not immortalised in the myrmicine literature, as the CAS proposed, may still get a warm glow from the feeling that they are making a contribution to the advancement of knowledge in a way which was previously open only to philanthropists with rather fatter wallets.在加州科学院的项目里,即使这些捐赠人不会因切叶蚁属文献而流芳千古,但能让他们看到自己为知识进步做出了贡献感到欣慰,因为之前,这种方式只属于那些钱包更鼓的捐赠人。 /201401/271442深圳康宁医院光子嫩肤手术多少钱深圳龙岗区人民医院做去疤手术多少钱

分页 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29