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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.
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 a Frenchman is reviving McDonald’s in Europe
A. When Denis Hennequin took over as the European boss of McDonald’s in
January 2004, the world’s biggest restaurant chain was showing signs of recovery
in America and Australia, but sales in Europe were sluggish or declining. One
exception was France, where Mr Hennequin had done a sterling job as head of the
group’s French subsidiary to sell more Big Macs to his compatriots. His task was
to replicate this success in all 41 of the European countries where
anti-globalisers’ favourite enemy operates.
B. So far Mr Hennequin is doing well. Last year European sales increased by
5.8% and the number of customers by 3.4%, the best annual results in nearly 15
years. Europe accounted for 36% of the group’s profits and for 28% of its sales.
December was an especially good month as customers took to seasonal menu
offerings in France and Britain, and to a promotion in Germany based on the game
of Monopoly.
C. Mr Hennequin’s recipe for revival is to be more open about his company’s
operations, to be “locally relevant”, and to improve the experience of visiting
his 6,400 restaurants. McDonald’s is blamed for making people fat, exploiting
workers, treating animals cruelly, polluting the environment and simply for
being American. Mr Hennequin says he wants to engage in a dialogue with the
public to address these concerns.
D. He introduced “open door” visitor days in each country which became hugely
popular. In Poland alone some 50,000 visitors came to McDonald’s through the
visitors’ programme last year. The Nutrition Information Initiative, launched
last year, put detailed labels on McDonald’s packaging with data on calories,
protein, fat, carbohydrates and salt content. The details are also printed on
tray-liners.
E. Mr Hennequin also wants people to know that “McJobs”, the low-paid menial
jobs at McDonald’s restaurants, are much better than people think. But some of
his efforts have backfired: last year he sparked a controversy with the
introduction of a “McPassport” that allows McDonald’s employees to work anywhere
in the European Union. Politicians accused the firm of a ploy to make cheap
labour from eastern Europe more easily available to McDonald’s managers across
the continent.
F. To stay in touch with local needs and preferences, McDonald’s employs
local bosses as much as possible. A Russian is running McDonald’s in Russia,
though a Serb is in charge of Germany. The group buys mainly from local
suppliers. Four-fifths of its supplies in France come from local farmers, for
example. (Some of the French farmers who campaigned against the company in the
late 1990s subsequently discovered that it was, in fact, buying their produce.)
And it hires celebrities such as Heidi Klum, a German model, as local brand
ambassadors.
G. In his previous job Mr Hennequin established a “design studio” in France
to spruce up his company’s drab restaurants and adapt the interior to local
tastes. The studio is now masterminding improvements everywhere in Europe. He
also set up a “food studio”, where cooks devise new recipes in response to local
trends.
H. Given France’s reputation as the most anti-American country in Europe, it
seems odd that McDonald’s revival in Europe is being led by a Frenchman, using
ideas cooked up in the French market. But France is in fact the company’s most
profitable market after America. The market where McDonald’s is weakest in
Europe is not France, but Britain.
I. “Fixing Britain should be his priority,” says David Palmer, a restaurant
analyst at UBS. Almost two-thirds of the 1,214 McDonald’s restaurants in Britain
are company-owned, compared with 40% in Europe and 15% in America. The company
suffers from the volatility of sales at its own restaurants, but can rely on
steady income from franchisees. So it should sell as many underperforming
outlets as possible, says Mr Palmer.
J. M.Mark Wiltamuth, an analyst at Morgan Stanley, estimates that European
company-owned restaurants’ margins will increase slightly to 16.4% in 2007. This
is still less than in the late 1990s and below America’s 18-19% today. But it is
much better than before Mr Hennequin’s reign. He is already being tipped as the
first European candidate for the group’s top job in Illinois. Nobody would call
that a McJob.
Notes to Reading Passage 1
1.sterling高质量的
e.g. He has many sterling qualities. 他身上有许多优秀的品质。
2. menial 不体面的, 乏味的(工作、职业)
3. spruce up打扮整齐、漂亮、装饰
4. mastermind指挥、谋划(一个计划或活动)
e.g. The police know who masterminded the robbery.警察知道是谁策划了那次抢劫。
5. underperform表现不佳表现出低于标准的工作水平、企业出现亏本
Questions 1-6
Do the following statements reflect the claims of the writer in Reading
Passage 1?
Write your answer in Boxes 1-6 on your answer sheet.
TRUE if the statement reflects the claims of the writer
FALSE if the statement contradicts the claims of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
1. McDonald was showing the sign of recovery in all European countries except
France after Denis Hennequin took office as the boss of Euro-markets.
2. Starting from last year, detailed labels are put on McDonald’s packaging
and detailed information is also printed on tray-liners.
3. France is said to be the most anti-American country in Europe, but the
ideas of the “open door” visiting days and “McPassport” are invented in the
French market.
4. Britain possesses the weakest McDonald market among European countries and
approximately 1214 McDonald’s restaurants are company-owned.
5. According to David Palmer, a restaurant analyst at UBS, David Hennequin
should treat the problem about McDonald in Britain as the most important
thing.
6. David Palmer suggested that the management of McDonalod in Italy should
sell as many its outlets which lose money in business as possible for
revival.
Questions 7-10
Choose the appropriate letters A-D and write them in boxes 7-10 on your answe
sheet.
7. The word “sterling” in line 3 of Paragraph A means__________.
A. difficult
B. menial
C. terrible
D. excellent
8. Which of the following statements on the accusation of MacDonald is NOT
TRUE?
A. It tends to make people fat.
B. Its operations are very vague.
C. It tends to exploit workers.
D. It tends to treat animals cruelly.
9. Which of the following measures taken by Denis Hennequin produced
undesired result?
A. “Food Studio” scheme.
B. “Open Door” visitor days.
C. The “McPassport” scheme.
D. The Nutrition Information Initiative.
10. What did Denis Hennequin do so as to respond to local trends?
A. set up a “Food Studio” .
B. established a “Design Studio”.
C. hired celebrities as local brand ambassadors.
D. employed local bosses as much as possible.
Questions 11-14
Complete each of the following statements (Questions 11-14) with words or
number taken from Reading Passage 1.
Write NO MORE THAN THREE WORDS for each answer.
Write your answers in boxes 11-14 on your answer sheet.
11. After January 2004, McDonald was making improvement following a period of
slump in America and Australia, but sales in Europe were ………………………….
12. Business of McDonald in France and Britain was particularly good in
December since customers took to ……………………………..
13. Compared with other countries, France is McDonald’s ………………………. next to
America.
14. ……………………. of McDonald’s restaurants in America are companied–owned and
the figure is much lower than that in Britain.
To begin with,"muzak"(音乐广播网 )was intended simplyto createasoothing(安慰)atmosphere.Recently,however,it's ecome big business —thanks in part to recentresearch.Dr.Ronald Milliman,an American marketing expert,hasshown that music can boost sales or increase factory roduction by as much as a third.But,it has to be light music.A fast one has no effect atall on sales.Slow music can increase receipts by 38%.This isprobably because shoppers slow down and have more opportunityto spot items they like to buy.Yet,slow music isn't alway sanswer.Dr.Milliman found,for example,that in restaurants slowmusic meant customers took longer to eat their meals,whichreduced overall sales.So restaurants owners might be welladvised to play up-tempo music to keep the customers moving—unless of course,the resulting indigestion leads tocomplaints!
练习：
1.The reason why background music is so popular isthat ______.
A.it can have a powerful effect on those who hear it
B.it can help to create a soothing atmosphere
C.it can boost sales or increase factory production erywhere
D.it can make customers eat their meals quickly
2.Background music means ________.
A.light music that customers enjoy mostB.fast music that makes people move
fast
C.slow music that can make customers enjoy their meals
D.the music you are listening to while you are doingomething
3.Restaurant owners complain about background musicbecause ______.
A.it results in indigestion
B.it increases their sales
C.it keeps customers moving
D.it decreases their sales
4.The word"up-tempo music"probably means_____.
A.slow music
B.fast music
C.light music
D.classical music
