读趣百科

1. A European spacecraft took off today to spearhead the search for another "Earth" among the stars.

2. The Corot space telescope blasted off aboard a Russian Soyuz rocket from the Baikonur cosmodrome in Kazakhstan shortly after 2.20pm.

3. Corot, short for convection rotation and planetary transits, is the first instrument capable of finding small rocky planets beyond the solar system. Any such planet situated in the right orbit stands a good chance of having liquid water on its surface, and quite possibly life, although a leading scientist involved in the project said it was unlikely to find "any little green men".

4. Developed by the French space agency, CNES, and partnered by the European Space Agency (ESA), Austria, Belgium, Germany, Brazil and Spain, Corot will monitor around 120,000 stars with its 27cm telescope from a polar orbit 514 miles above the Earth. Over two and a half years, it will focus on five to six different areas of the sky, measuring the brightness of about 10,000 stars every 512 seconds.

5. "At the present moment we are hoping to find out more about the nature of planets around stars which are potential habitats. We are looking at habitable planets, not inhabited planets. We are not going to find any little green men," Professor Ian Roxburgh, an ESA scientist who has been involved with Corot since its inception, told the BBC Radio 4 Today programme.

6. Prof Roxburgh said it was hoped Corot would find "rocky planets that could develop an atmosphere and, if they are the right distance from their parent star, they could have water".

7. To search for planets, the telescope will look for the dimming of starlight caused when an object passes in front of a star, known as a "transit". Although it will take more sophisticated space telescopes planned in the next 10 years to confirm the presence of an Earth-like planet with oxygen and liquid water, Corot will let scientists know where to point their lenses.

8. Measurements of minute changes in brightness will enable scientists to detect giant Jupiter-like gas planets as well as small rocky ones. It is the rocky planets - that could be no bigger than about twice the size of the Earth - which will cause the most excitement. Scientists expect to find between 10 and 40 of these smaller planets.

9. Corot will also probe into stellar interiors by studying the acoustic waves that ripple across the surface of stars, a technique called "asteroseismology".

10. The nature of the ripples allows astronomers to calculate a star’s precise mass, age and chemical composition.

11. "A planet passing in front of a star can be detected by the fall in light from that star. Small oscillations of the star also produce changes in the light emitted, which reveal what the star is made of and how they are structured internally. This data will provide a major boost to our understanding of how stars form and evolve," Prof Roxburgh said.

12. Since the discovery in 1995 of the first "exoplanet" - a planet orbiting a star other than the Sun - more than 200 others have been found by ground-based observatories.

13. Until now the usual method of finding exoplanets has been to detect the "wobble" their gravity imparts on parent stars. But only giant gaseous planets bigger than Jupiter can be found this way, and they are unlikely to harbour life.

14. In the 2010s, ESA plans to launch Darwin, a fleet of four or five interlinked space telescopes that will not only spot small rocky planets, but analyse their atmospheres for signs of biological activity.

15. At around the same time, the US space agency, Nasa, will launch Terrestrial Planet Finder, another space telescope designed to locate Earth-like planets.

Choose the appropriate letter from A-D for question 1.

1. Corot is an instrument which

(A) can help to search for certain planets

(B) is used to find planets in the orbit

(C) can locate planets with human beings

(D) can spot any planets with water.

Do the following statements agree with the information given in the reading passage? For questions 2-5 write

TRUE if the statement agrees with the information

FALSE if the statement contraicts the information

NOT GIVEN if there is no information on this in the passage

2. Scientists are trying to find out about the planets that can be inhabited.

3. BBC Radio 4 recently focuses on the broadcasting of Corot.

4. Passing objects might cause a fall in light.

5. Corot can tell whether there is another Earth-like planet.

Based on your reading of the passage, complete the sentences below with words taken from the passage. Use NO MORE THAN THREE WORDS for each answer.

With measurements, scientists will be able to search for some gaseous and rocky planets. They will be extremely excited if they can discover some small 6. __________, the expected number of which could be up to 7. __________ .

Corot will enable scientists to study the 8. __________ of stars. In this way, a star’s mass, age and chemical composition can be calculated.

According to Prof Roxburgh, changes in light can be caused by passing planets or star 9. __________. The related statistics can gain us a better 10. __________ of the star formation and evolvement.

Observatories have found many exoplanets, which are 11. __________ other stars than the Sun. The common way used in finding exoplanets can only detect huge gas planets, which do not 12. ___________ .

With the launching of Darwin, astronomers will be able to analyse whether those rocky planets have 13. __________ for life.

Don't wash those fossils!

Standard museum practice can wash away DNA.

1.Washing, brushing and varnishing fossils — all standard conservation treatments used by many fossil hunters and museum curators alike — vastly reduces the chances of recovering ancient DNA.

2.Instead, excavators should be handling at least some of their bounty with gloves, and freezing samples as they are found, dirt and all, concludes a paper in the Proceedings of the National Academy of Sciences today.

3.Although many palaeontologists know anecdotally that this is the best way to up the odds of extracting good DNA, Eva-Maria Geigl of the Jacques Monod Institute in Paris, France, and her colleagues have now shown just how important conservation practices can be.This information, they say, needs to be hammered home among the people who are actually out in the field digging up bones.

4.Geigl and her colleagues looked at 3,200-year-old fossil bones belonging to a single individual of an extinct cattle species, called an aurochs.The fossils were dug up at a site in France at two different times — either in 1947, and stored in a museum collection, or in 2004, and conserved in sterile conditions at -20 oC.

5.The team's attempts to extract DNA from the 1947 bones all failed.The newly excavated fossils, however, all yielded DNA.

6.Because the bones had been buried for the same amount of time, and in the same conditions, the conservation method had to be to blame says Geigl."As much DNA was degraded in these 57 years as in the 3,200 years before," she says.

Wash in, wash out

7.Because many palaeontologists base their work on the shape of fossils alone, their methods of conservation are not designed to preserve DNA, Geigl explains.

8.The biggest problem is how they are cleaned.Fossils are often washed together on-site in a large bath, which can allow water — and contaminants in the form of contemporary DNA — to permeate into the porous bones."Not only is the authentic DNA getting washed out, but contamination is getting washed in," says Geigl.

9.Most ancient DNA specialists know this already, says Hendrik Poinar, an evolutionary geneticist at McMaster University in Ontario, Canada.But that doesn't mean that best practice has become widespread among those who actually find the fossils.

10.Getting hold of fossils that have been preserved with their DNA in mind relies on close relationships between lab-based geneticists and the excavators, says palaeogeneticist Svante P bo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.And that only occurs in exceptional cases, he says.

11.P bo's team, which has been sequencing Neanderthal DNA, continually faces these problems."When you want to study ancient human and Neanderthal remains, there's a big issue of contamination with contemporary human DNA," he says.

12.This doesn't mean that all museum specimens are fatally flawed, notes P bo.The Neanderthal fossils that were recently sequenced in his own lab, for example, had been part of a museum collection treated in the traditional way.But P bo is keen to see samples of fossils from every major find preserved in line with Geigl's recommendations — just in case.

Warm and wet

13.Geigl herself believes that, with cooperation between bench and field researchers, preserving fossils properly could open up avenues of discovery that have long been assumed closed.

14.Much human cultural development took place in temperate regions.DNA does not survive well in warm environments in the first place, and can vanish when fossils are washed and treated.For this reason, Geigl says, most ancient DNA studies have been done on permafrost samples, such as the woolly mammoth, or on remains sheltered from the elements in cold caves — including cave bear and Neanderthal fossils.

15.Better conservation methods, and a focus on fresh fossils, could boost DNA extraction from more delicate specimens, says Geigl.And that could shed more light on the story of human evolution.

(640 words nature )

Glossary

Palaeontologists 古生物学家

Aurochs 欧洲野牛

Neanderthal (人类学)尼安德特人，旧石器时代的古人类。

Permafrost (地理)永冻层

Questions 1-6

Answer the following questions by using NO MORE THAN THREE WORDS for each answer.

1.How did people traditionally treat fossils?

2.What suggestions do Geigl and her colleagues give on what should be done when fossils are found?

3.What problems may be posed if fossil bones are washed on-site? Name ONE.

4.What characteristic do fossil bones have to make them susceptible to be contaminated with contemporary DNA when they are washed?

5.What could be better understood when conservation treatments are improved?

6.The passage mentioned several animal species studied by researchers.How many of them are mentioned?

Questions 7-11

Do the following statements agree with the information given in the passage? Please write TRUE if the statement agrees with the writer FALSE if the statement does not agree with the writer NOT GIVEN if there is no information about this in the passage.

7.In their paper published in the Proceedings of the National Academy of Sciences，Geigl and her colleagues have shown what conservation practices should be followed to preserve ancient DNA.

8.The fossil bones that Geigl and her colleagues studied are all from the same aurochs.

9.Geneticists don't have to work on site.

10.Only newly excavated fossil bones using new conservation methods suggested by Geigl and her colleagues contain ancient DNA.

11.Paabo is still worried about the potential problems caused by treatments of fossils in traditional way.

Questions 12-13

Complete the following the statements by choosing letter A-D for each answer.

12.“This information” in paragraph 3 indicates:

[A] It is critical to follow proper practices in preserving ancient DNA.

[B] The best way of getting good DNA is to handle fossils with gloves.

[C] Fossil hunters should wear home-made hammers while digging up bones.

[D] Many palaeontologists know how one should do in treating fossils.

13.The study conducted by Geigl and her colleagues suggests:

[A] the fact that ancient DNA can not be recovered from fossil bones excavated in the past.

[B] the correlation between the amount of burying time and that of the recovered DNA.

[C] the pace at which DNA degrades.

[D] the correlation between conservation practices and degradation of DNA.

1.The failure of a high-profile cholesterol drug has thrown a spotlight on the complicated machinery that regulates cholesterol levels.But many researchers remain confident that drugs to boost levels of 'good' cholesterol are still one of the most promising means to combat spiralling heart disease.

2.Drug company Pfizer announced on 2 December that it was cancelling all clinical trials of torcetrapib，a drug designed to raise heart-protective high-density lipoproteins (HDLs).In a trial of 15000 patients，a safety board found that more people died or suffered cardiovascular problems after taking the drug plus a cholesterol-lowering statin than those in a control group who took the statin alone.

3.The news came as a kick in the teeth to many cardiologists because earlier tests in animals and people suggested it would lower rates of cardiovascular disease."There have been no red flags to my knowledge," says John Chapman，a specialist in lipoproteins and atherosclerosis at the National Institute for Health and Medical Research (INSERM) in Paris who has also studied torcetrapib."This cancellation came as a complete shock."

4.Torcetrapib is one of the most advanced of a new breed of drugs designed to raise levels of HDLs，which ferry cholesterol out of artery-clogging plaques to the liver for removal from the body.Specifically，torcetrapib blocks a protein called cholesterol ester transfer protein (CETP)，which normally transfers the cholesterol from high-density lipoproteins to low density，plaque-promoting ones.Statins，in contrast，mainly work by lowering the 'bad' low-density lipoproteins.

Under pressure

5.Researchers are now trying to work out why and how the drug backfired，something that will not become clear until the clinical details are released by Pfizer.One hint lies in evidence from earlier trials that it slightly raises blood pressure in some patients.It was thought that this mild problem would be offset by the heart benefits of the drug.But it is possible that it actually proved fatal in some patients who already suffered high blood pressure.If blood pressure is the explanation，it would actually be good news for drug developers because it suggests that the problems are specific to this compound.Other prototype drugs that are being developed to block CETP work in a slightly different way and might not suffer the same downfall.

6.But it is also possible that the whole idea of blocking CETP is flawed，says Moti Kashyap，who directs atherosclerosis research at the VA Medical Center in Long Beach，California.When HDLs excrete cholesterol in the liver，they actually rely on LDLs for part of this process.So inhibiting CETP，which prevents the transfer of cholesterol from HDL to LDL，might actually cause an abnormal and irreversible accumulation of cholesterol in the body."You're blocking a physiologic mechanism to eliminate cholesterol and effectively constipating the pathway," says Kashyap.Going up

7.Most researchers remain confident that elevating high density lipoproteins levels by one means or another is one of the best routes for helping heart disease patients.But HDLs are complex and not entirely understood.One approved drug，called niacin，is known to both raise HDL and reduce cardiovascular risk but also causes an unpleasant sensation of heat and tingling.Researchers are exploring whether they can bypass this side effect and whether niacin can lower disease risk more than statins alone.Scientists are also working on several other means to bump up high-density lipoproteins by，for example，introducing synthetic HDLs."The only thing we know is dead in the water is torcetrapib，not the whole idea of raising HDL," says Michael Miller，director of preventive cardiology at the University of Maryland Medical Center，Baltimore.

Questions 7-13

Match torcetrapib，HDLs，statin and CETP with their functions (Questions 8-13)..Write the correct letter A，B，C or D in boxes 8-13 on your answer sheet.NB You may use any letter more than once.

7.It has been administered to over 10,000 subjects in a clinical trial.

8.It could help rid human body of cholesterol.

9.Researchers are yet to find more about it.

10.It was used to reduce the level of cholesterol.

11.According to Kashyap，it might lead to unwanted result if it's blocked.

12.It produced contradictory results in different trials.

13.It could inhibit LDLs.List of choices

A.TorcetrapicB.HDLSC.StatinD.CETP

Rogue theory of smell gets a boost

1.A controversial theory of how we smell, which claims that our fine sense of odour depends on quantum mechanics, has been given the thumbs up by a team of physicists.

2.Calculations by researchers at University College London (UCL) show that the idea that we smell odour molecules by sensing their molecular vibrations makes sense in terms of the physics involved.

3.That's still some way from proving that the theory, proposed in the mid-1990s by biophysicist Luca Turin, is correct.But it should make other scientists take the idea more seriously.

4."This is a big step forward," says Turin, who has now set up his own perfume company Flexitral in Virginia.He says that since he published his theory, "it has been ignored rather than criticized."

5.Most scientists have assumed that our sense of smell depends on receptors in the nose detecting the shape of incoming molecules, which triggers a signal to the brain.This molecular 'lock and key' process is thought to lie behind a wide range of the body's detection systems: it is how some parts of the immune system recognise invaders, for example, and how the tongue recognizes some tastes.

6.But Turin argued that smell doesn't seem to fit this picture very well.Molecules that look almost identical can smell very different — such as alcohols, which smell like spirits, and thiols, which smell like rotten eggs.And molecules with very different structures can smell similar.Most strikingly, some molecules can smell different — to animals, if not necessarily to humans — simply because they contain different isotopes (atoms that are chemically identical but have a different mass).

7.Turin's explanation for these smelly facts invokes the idea that the smell signal in olfactory receptor proteins is triggered not by an odour molecule's shape, but by its vibrations, which can enourage an electron to jump between two parts of the receptor in a quantum-mechanical process called tunnelling.This electron movement could initiate the smell signal being sent to the brain.

8.This would explain why isotopes can smell different: their vibration frequencies are changed if the atoms are heavier.Turin's mechanism, says Marshall Stoneham of the UCL team, is more like swipe-card identification than a key fitting a lock.

9.Vibration-assisted electron tunnelling can undoubtedly occur — it is used in an experimental technique for measuring molecular vibrations."The question is whether this is possible in the nose," says Stoneham's colleague, Andrew Horsfield.

10.Stoneham says that when he first heard about Turin's idea, while Turin was himself based at UCL, "I didn't believe it".But, he adds, "because it was an interesting idea, I thought I should prove it couldn't work.I did some simple calculations, and only then began to feel Luca could be right." Now Stoneham and his co-workers have done the job more thoroughly, in a paper soon to be published in Physical Review Letters.

11.The UCL team calculated the rates of electron hopping in a nose receptor that has an odorant molecule bound to it.This rate depends on various properties of the biomolecular system that are not known, but the researchers could estimate these parameters based on typical values for molecules of this sort.

12.The key issue is whether the hopping rate with the odorant in place is significantly greater than that without it.The calculations show that it is — which means that odour identification in this way seems theoretically possible.

13.But Horsfield stresses that that's different from a proof of Turin's idea."So far things look plausible, but we need proper experimental verification.We're beginning to think about what experiments could be performed."

14.Meanwhile, Turin is pressing ahead with his hypothesis."At Flexitral we have been designing odorants exclusively on the basis of their computed vibrations," he says."Our success rate at odorant discovery is two orders of magnitude better than the competition." At the very least, he is putting his money where his nose is.

Questions 5-9

Complete the sentences below with words from the passage.Use NO MORE THAN THREE WORDS for each answer.

5.The hypothesis that we smell by sensing the molecular vibration was made by ______.

6.Turin's company is based in ______.

7.Most scientists believed that our nose works in the same way as our ______.

8.Different isotopes can smell different when ______ weigh differently.

9.According to Audrew Horsfield, it is still to be proved that ______ could really occur in human nose.

How shops can exploit people's herd mentality to increase sales

1.A TRIP to the supermarket may not seem like an exercise in psychological warfare—but it is.Shopkeepers know that filling a store with the aroma of freshly baked bread makes people feel hungry and persuades them to buy more food than they had intended.Stocking the most expensive products at eye level makes them sell faster than cheaper but less visible competitors.Now researchers are investigating how “swarm intelligence” (that is，how ants，bees or any social animal，including humans，behave in a crowd) can be used to influence what people buy.

2.At a recent conference on the simulation of adaptive behaviour in Rome，Zeeshan-ul-hassan Usmani，a computer scientist from the Florida Institute of Technology，described a new way to increase impulse buying using this phenomenon.Supermarkets already encourage shoppers to buy things they did not realise they wanted: for instance，by placing everyday items such as milk and eggs at the back of the store，forcing shoppers to walk past other tempting goods to reach them.Mr Usmani and Ronaldo Menezes，also of the Florida Institute of Technology，set out to enhance this tendency to buy more by playing on the herd instinct.The idea is that，if a certain product is seen to be popular，shoppers are likely to choose it too.The challenge is to keep customers informed about what others are buying.

3.Enter smart-cart technology.In Mr Usmani's supermarket every product has a radio frequency identification tag，a sort of barcode that uses radio waves to transmit information，and every trolley has a scanner that reads this information and relays it to a central computer.As a customer walks past a shelf of goods，a screen on the shelf tells him how many people currently in the shop have chosen that particular product.If the number is high，he is more likely to select it too.

4.Mr Usmani's “swarm-moves” model appeals to supermarkets because it increases sales without the need to give people discounts.And it gives shoppers the satisfaction of knowing that they bought the “right” product—that is，the one everyone else bought.The model has not yet been tested widely in the real world，mainly because radio frequency identification technology is new and has only been installed experimentally in some supermarkets.But Mr Usmani says that both Wal-Mart in America and Tesco in Britain are interested in his work，and testing will get under way in the spring.

5.Another recent study on the power of social influence indicates that sales could，indeed，be boosted in this way.Matthew Salganik of Columbia University in New York and his colleagues have described creating an artificial music market in which some 14,000 people downloaded previously unknown songs.The researchers found that when people could see the songs ranked by how many times they had been downloaded，they followed the crowd.When the songs were not ordered by rank，but the number of times they had been downloaded was displayed，the effect of social influence was still there but was less pronounced.People thus follow the herd when it is easy for them to do so.

6.In Japan a chain of convenience shops called RanKing RanQueen has been ordering its products according to sales data from department stores and research companies.The shops sell only the most popular items in each product category，and the rankings are updated weekly.Icosystem，a company in Cambridge，Massachusetts，also aims to exploit knowledge of social networking to improve sales.

7.And the psychology that works in physical stores is just as potent on the internet.Online retailers such as Amazon are adept at telling shoppers which products are popular with like-minded consumers.Even in the privacy of your home，you can still be part of the swarm.

Questions 1-6

Complete the sentences below with words taken from the reading passage.Use NO MORE THAN THREE WORDS for each answer.

1.Shopowners realize that the smell of _______________ can increase sales of food products.

2.In shops，products shelved at a more visible level sell better even if they are more _______________.

3.According to Mr.Usmani，with the use of “swarm intelligence” phenomenon，a new method can be applied to encourage _______________.

4.On the way to everyday items at the back of the store，shoppers might be tempted to buy _______________.

5.If the number of buyers shown on the _______________ is high，other customers tend to follow them.

6.Using the “swarm-moves” model，shopowners do not have to give customers _______________ to increase sales.