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湖北医药学院附属襄阳医院治疗睾丸炎多少钱襄阳人民医院资料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樊城妇幼保健院中医院治疗女性疾病怎么样 襄阳市中医医院治男科靠谱吗?

襄阳市割包皮手术的医院襄阳市四医院是什么时候成立的 Woodpeckers puncture the bark of dead or dying trees,also known as snags, to find the wood-boring insects that makeup their diet, and some species also excavate cavities in thesetrees for their nests.啄木鸟啄破死树或垂死的树的树皮,觅得吃木头的昆虫为食。有些物种也会在这些树上筑巢。So where does the fungus come in?那么真菌是从哪来的呢?Well, scientists observed that the snags woodpeckersexcavate generally contain decayed wood, which is caused by wood-decay fungi.恩,科学家们观察到啄木鸟啄洞的断枝通常包含由木腐菌造成的蛀木。Right. And thisled them to wonder whether woodpeckers are attracted to certain types of decay, or if theyrethe ones actually sping the fungus that causes the decay.是的。而且这引起观察家们思考:是某些类型的腐烂吸引了啄木鸟,还是说啄木鸟实际上传播了引起腐烂的真菌呢?So what did come first?那么到底哪个在先?Well, it turns out that the relationship between the two is pretty complex.恩,事实明两者关系相当复杂。When woodpeckers puncture bark, they provide a way for airborne fungal spores to infect the wood.当啄木鸟啄树皮时,它们为空气传播的真菌孢子感染树木提供了方便,They also act as vectors, unintentionally picking up fungal spores and other microbes from onesnag and carrying them in their beaks to another.它们同时也是带菌者,无意中携带了真菌孢子和来自某根断枝的其他细菌,它们的喙载着这些细菌再传播给其他树木。And not surprisingly, species of woodpeckersthat nest in cavities carry a significantly larger number of these, which is synergistic, because the decay makes it easier for them to excavate.毫不奇怪的是,那些在树洞里筑巢的啄木鸟携带着更大量的真菌,它们是协同作用着的,因为腐烂使得啄木鸟啄洞更容易了。So even though we still dont know which came first, this also isnt merely an intellectual exercise.因此,即使我们不知道先有哪个,这也不仅仅是一种智力测验。Woodpeckers are pretty important ecologically because the sites they excavate are used forforaging, roosting, and nesting by many other species as well.从生态学的观点看,啄木鸟的角色相当重要,因为啄木鸟挖掘的树洞可以用于觅食,栖息,还可以被其他物种用来筑巢。And now that theres debate overwhether snags contribute to forest fires and should be removed, its especially important to studypotential ramifications.既然人们关于断枝是否会导致森林火灾而应该被移除争论不休,那么研究一下可能出现的后果就特别重要了。 201405/296982襄阳人民医院预约挂号系统

襄阳哪家做白癜风检查医院哪家技术好Italian payment practices意大利的付习惯Unhealthy delays有害的延误Late payments are an Italian speciality—particularly in health care延迟付是意大利的特色——尤其在医药保健领域IN MEDICINE speed is of the essence.在医药领域,速度就是核心。If the ambulance arrives a minute late, the patient may be dead.如果救护车晚到一分钟,病人就可能死亡了。Italian paramedics are no doubt as swift as those in other countries.意大利的护理人员无疑同其他国家一样行动迅速。But Italys health-care authorities are shamefully slow when it comes to paying suppliers—making it difficult for them to survive.但谈到向供应商付时,意大利的医疗机构就慢的令人羞耻了—简直让供应商们难以生存。Were still waiting to be paid for goods sold in , says Stefano Rimondi, the managing director of Bellco, a maker of equipment for dialysis with revenues of more than 100m and a workforce of 360 people.我们还在等年出售的货物的付款,Bellco公司的常务董事Stefano Rimondi说道。Bellco是一家渗透设备制造商,拥有360名员工,每年收入超过1亿欧元。We have one employee working full-time chasing up late payers, he adds.他补充道,我们有一个员工全职专司向延迟付款人追讨款项。Bellco is not the only company to suffer.Bellco不是唯一一家深受其害的公司。The 250 other members of Assobiomedica, a trade group for firms that supply medical equipment, are owed 5.6 billion;提供医疗设备的贸易组织,意大利生物医药联合会下属的250家公司有未付款56亿欧元;those of Farmindustria, which represents 200 pharmaceutical firms, are waiting for 4 billion.意大利制药工业协会下属的200家制药公司则有未付款40亿欧元。The farther south you look, the longer the delays in payment.你往南看的越远,付的延迟时间就越长。The Friuli and Trentino-Alto Adige regions in north-eastern Italy and Valle dAosta in the north-west settle bills after about three months.在意大利东北部的Friuli 和Trentino-Alto Adige区域,以及在西北部的Valle dAosta都在三个月后付账单。The regions of Calabria and Molise pay on average after two years.Calabria 和 Molise区的人平均两年后才付账。The record is held by one Neapolitan health authority:那不勒斯省中某市的卫生部门保持着相关记录:some of its suppliers have been waiting for more than four-and-a-half years.他的一些供应商已经等了至少四年半了。Small Italian firms that rely on the home market are hit particularly hard.一些依赖家庭市场的意大利企业尤其损失严重。Often they cannot get bank financing at reasonable interest rates.他们通常不能以合理的利率从贷款。And long delays in payment create all kinds of tax and accounting headaches.而长时间延误付款将导致税收和会计方面的一系列问题。Suing late-payers doesnt help much.起诉延迟付款者也没有太大作用。Courts are at least as slow as health-care authorities.法院的速度至少和医疗机构一样慢。In five regions a law even blocks the use of courts to compel authorities to cough up.甚至有一项法律在五个地区中禁止法院强制官员吐出资金。Once we were able to recover about 5m of interest a year, but now weve had to give up, says the executive of a large American drugmaker, which had started to take legal action in 2007.一家大型美国制药公司在2007年采取法律行动以后说道:曾经我们可以收到一年大约500万欧元的利息,但现在我们放弃了。Pharmaceutical firms cannot simply stay clear of the worst offenders:制药公司不能简单的远离最极端的冒犯者们:they are legally required to supply drugs even to notoriously slow authorities.法律甚至要求这些为慢的臭名昭著的官员提供药品。Desperate measures are also unlikely to help.令人绝望的法规同样很难起到作用。Starting a boycott of late-paying authorities could trigger an antitrust investigation.启动对延迟付款官员的联合抵制将触发反垄断调查。And paying sweeteners to move invoices to the top of the list can land you behind bars.而通过贿赂使账单排到列表最顶端的举动将使你锒铛入狱。Some suppliers are pinning their hopes on new European Union legislation which requires health-care authorities to settle bills within 60 days;一些供应商寄希望于要求医疗机构在60天内付款的欧盟监管新条例;it takes effect in March next year.此条例将于明年三月份生效。Yet Mr Rimondi would be shocked if things improved:但如果情况真的有所改进的话,Rimondi先生会感到震惊,Some clause will be dreamed up so that the directive can be dodged in Italy.将有一些条款被设计出来,让意大利逃过监管。 /201307/247869 宜城妇幼保健院割包皮价格表襄阳市中医院咨询



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