-----Didyounoticehimcomein?
-----No.I________afootballgame.
D
暂无解析
-----Tinahadnothingforbreakfast,____________she?
-----_____________.Shehadsomebreadandmilk.
-----Didyounoticehimcomein?
-----No.I________afootballgame.
Don'twashthosefossils!
StandardmuseumpracticecanwashawayDNA.
1.Washing,brushingandvarnishingfossils—allstandardconservationtreatmentsusedbymanyfossilhuntersandmuseumcuratorsalike—vastlyreducesthechancesofrecoveringancientDNA.
2.Instead,excavatorsshouldbehandlingatleastsomeoftheirbountywithgloves,andfreezingsamplesastheyarefound,dirtandall,concludesapaperintheProceedingsoftheNationalAcademyofSciencestoday.
3.AlthoughmanypalaeontologistsknowanecdotallythatthisisthebestwaytouptheoddsofextractinggoodDNA,Eva-MariaGeigloftheJacquesMonodInstituteinParis,France,andhercolleagueshavenowshownjusthowimportantconservationpracticescanbe.Thisinformation,theysay,needstobehammeredhomeamongthepeoplewhoareactuallyoutinthefielddiggingupbones.
4.Geiglandhercolleagueslookedat3,200-year-oldfossilbonesbelongingtoasingleindividualofanextinctcattlespecies,calledanaurochs.ThefossilsweredugupatasiteinFranceattwodifferenttimes—eitherin1947,andstoredinamuseumcollection,orin2004,andconservedinsterileconditionsat-20oC.
5.Theteam'sattemptstoextractDNAfromthe1947bonesallfailed.Thenewlyexcavatedfossils,however,allyieldedDNA.
6.Becausetheboneshadbeenburiedforthesameamountoftime,andinthesameconditions,theconservationmethodhadtobetoblamesaysGeigl."AsmuchDNAwasdegradedinthese57yearsasinthe3,200yearsbefore,"shesays.
Washin,washout
7.Becausemanypalaeontologistsbasetheirworkontheshapeoffossilsalone,theirmethodsofconservationarenotdesignedtopreserveDNA,Geiglexplains.
8.Thebiggestproblemishowtheyarecleaned.Fossilsareoftenwashedtogetheron-siteinalargebath,whichcanallowwater—andcontaminantsintheformofcontemporaryDNA—topermeateintotheporousbones."NotonlyistheauthenticDNAgettingwashedout,butcontaminationisgettingwashedin,"saysGeigl.
9.MostancientDNAspecialistsknowthisalready,saysHendrikPoinar,anevolutionarygeneticistatMcMasterUniversityinOntario,Canada.Butthatdoesn'tmeanthatbestpracticehasbecomewidespreadamongthosewhoactuallyfindthefossils.
10.GettingholdoffossilsthathavebeenpreservedwiththeirDNAinmindreliesoncloserelationshipsbetweenlab-basedgeneticistsandtheexcavators,sayspalaeogeneticistSvantePbooftheMaxPlanckInstituteforEvolutionaryAnthropologyinLeipzig,Germany.Andthatonlyoccursinexceptionalcases,hesays.
11.Pbo'steam,whichhasbeensequencingNeanderthalDNA,continuallyfacestheseproblems."WhenyouwanttostudyancienthumanandNeanderthalremains,there'sabigissueofcontaminationwithcontemporaryhumanDNA,"hesays.
12.Thisdoesn'tmeanthatallmuseumspecimensarefatallyflawed,notesPbo.TheNeanderthalfossilsthatwererecentlysequencedinhisownlab,forexample,hadbeenpartofamuseumcollectiontreatedinthetraditionalway.ButPboiskeentoseesamplesoffossilsfromeverymajorfindpreservedinlinewithGeigl'srecommendations—justincase.
Warmandwet
13.Geiglherselfbelievesthat,withcooperationbetweenbenchandfieldresearchers,preservingfossilsproperlycouldopenupavenuesofdiscoverythathavelongbeenassumedclosed.
14.Muchhumanculturaldevelopmenttookplaceintemperateregions.DNAdoesnotsurvivewellinwarmenvironmentsinthefirstplace,andcanvanishwhenfossilsarewashedandtreated.Forthisreason,Geiglsays,mostancientDNAstudieshavebeendoneonpermafrostsamples,suchasthewoollymammoth,oronremainsshelteredfromtheelementsincoldcaves—includingcavebearandNeanderthalfossils.
15.Betterconservationmethods,andafocusonfreshfossils,couldboostDNAextractionfrommoredelicatespecimens,saysGeigl.Andthatcouldshedmorelightonthestoryofhumanevolution.
(640wordsnature)
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
Questions1-6
AnswerthefollowingquestionsbyusingNOMORETHANTHREEWORDSforeachanswer.
1.Howdidpeopletraditionallytreatfossils?
2.WhatsuggestionsdoGeiglandhercolleaguesgiveonwhatshouldbedonewhenfossilsarefound?
3.Whatproblemsmaybeposediffossilbonesarewashedon-site?NameONE.
4.WhatcharacteristicdofossilboneshavetomakethemsusceptibletobecontaminatedwithcontemporaryDNAwhentheyarewashed?
5.Whatcouldbebetterunderstoodwhenconservationtreatmentsareimproved?
6.Thepassagementionedseveralanimalspeciesstudiedbyresearchers.Howmanyofthemarementioned?
Questions7-11
Dothefollowingstatementsagreewiththeinformationgiveninthepassage?PleasewriteTRUEifthestatementagreeswiththewriterFALSEifthestatementdoesnotagreewiththewriterNOTGIVENifthereisnoinformationaboutthisinthepassage.
7.IntheirpaperpublishedintheProceedingsoftheNationalAcademyofSciences,GeiglandhercolleagueshaveshownwhatconservationpracticesshouldbefollowedtopreserveancientDNA.
8.ThefossilbonesthatGeiglandhercolleaguesstudiedareallfromthesameaurochs.
9.Geneticistsdon'thavetoworkonsite.
10.OnlynewlyexcavatedfossilbonesusingnewconservationmethodssuggestedbyGeiglandhercolleaguescontainancientDNA.
11.Paaboisstillworriedaboutthepotentialproblemscausedbytreatmentsoffossilsintraditionalway.
Questions12-13
CompletethefollowingthestatementsbychoosingletterA-Dforeachanswer.
12.“Thisinformation”inparagraph3indicates:
[A]ItiscriticaltofollowproperpracticesinpreservingancientDNA.
[B]ThebestwayofgettinggoodDNAistohandlefossilswithgloves.
[C]Fossilhuntersshouldwearhome-madehammerswhilediggingupbones.
[D]Manypalaeontologistsknowhowoneshoulddointreatingfossils.
13.ThestudyconductedbyGeiglandhercolleaguessuggests:
[A]thefactthatancientDNAcannotberecoveredfromfossilbonesexcavatedinthepast.
[B]thecorrelationbetweentheamountofburyingtimeandthatoftherecoveredDNA.
[C]thepaceatwhichDNAdegrades.
[D]thecorrelationbetweenconservationpracticesanddegradationofDNA.
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
Felicity Lawrence
Thursday December 28, 2006
The Guardian
1. Consumers are to be presented with two rival new year advertising campaigns as the Food Standards Agency goes public in its battle with the industry over the labelling of unhealthy foods.
2. The Guardian has learned that the FSA will launch a series of 10-second television adverts in January telling shoppers how to follow a red, amber and green traffic light labelling system on the front of food packs, which is designed to tackle Britain’s obesity epidemic.
3. The campaign is a direct response to a concerted attempt by leading food manufacturers and retailers, including Kellogg’s and Tesco, to derail the system. The industry fears that traffic lights would demonise entire categories of foods and could seriously damage the market for those that are fatty, salty or high in sugar.
4. The UK market for breakfast cereals is worth £1.27bn a year and the manufacturers fear it will be severely dented if red light labels are put on packaging drawing attention to the fact that the majority are high in salt and/or sugar.
5. The industry is planning a major marketing campaign for a competing labelling system which avoids colour-coding in favour of information about the percentage of "guideline daily amounts" (GDAs) of fat, salt and sugar contained in their products.
6. The battle for the nation’s diet comes as new rules on television advertising come into force in January which will bar adverts for unhealthy foods from commercial breaks during programmes aimed at children. Sources at the TV regulators are braced for a legal challenge from the industry and have described the lobbying efforts to block any new ad ban or colour-coded labelling as "the most ferocious we’ve ever experienced".
7. Ofcom’s chief executive, Ed Richards, said: "We are prepared to face up to any legal action from the industry, but we very much hope it will not be necessary." The FSA said it was expecting an onslaught from the industry in January. Senior FSA officials said the manufacturers’ efforts to undermine its proposals on labelling could threaten the agency’s credibility.
8. Terrence Collis, FSA director of communications, dismissed claims that the proposals were not based on science. "We have some of the most respected scientists in Europe, both within the FSA and in our independent advisory committees. It is unjustified and nonsensical to attack the FSA’s scientific reputation and to try to undermine its credibility."
9. The FSA is understood to have briefed its ad agency, United, before Christmas, and will aim to air ads that are "non-confrontational, humorous and factual" as a counterweight to industry’s efforts about the same time. The agency, however, will have a tiny fraction of the budget available to the industry.
10. Gavin Neath, chairman of Unilever UK and president of the Food and Drink Federation, has said that the industry has made enormous progress but could not accept red "stop" signs on its food.
11. Alastair Sykes, chief executive of Nestlé UK, said that under the FSA proposals all his company’s confectionery and most of its cereals would score a red. "Are we saying people shouldn’t eat confectionery? We’re driven by consumers and what they want, and much of what we do has been to make our products healthier," he said.
12. Chris Wermann, director of communications at Kellogg’s, said: "In principle we could never accept traffic light labelling."
13. The rival labelling scheme introduced by Kellogg’s, Danone, Unilever, Nestlé, Kraft and Tesco and now favoured by 21 manufacturers, uses an industry-devised system based on identifying GDAs of key nutrients. Tesco says it has tested both traffic lights and GDA labels in its stores and that the latter increased sales of healthier foods.
14. But the FSA said it could not live with this GDA system alone because it was "not scientific" or easy for shoppers to understand at a glance.
Questions 1-6
Answer the questions below using NO MORE THAN THREE WORDS from the passage for each answer.
1. When will instructions be given on reading the color-coded labels?
2. Where can customers find the red light labels?
3. What problem is the FSA trying to handle with the labeling system?
4. Which product sells well but may not be healthy?
5. What information, according to the manufacturers, can be labeled on products?
6. What can not be advertised during children’s programmes?
Questions 7-13
Use the information in the text to match the people (listed A-E) with the opinions (listed 7-13) below. Write the appropriate letter (A-E) for questions 1-7.
NB You may use any letter more than once.
A Ed Richard
B Terrence Collis
C Gavin Neath
D Alastair Sykes
E Chris Wermann
7. Generally we will not agree to use the red light labels.
8. It is unreasonable to doubt if FSA is trustworthy.
9. We are trying to meet our consumers’ needs.
10. The food industry has been improving greatly.
11. The color-coded labeling system is scientific.
12. Our products will be labeled unhealthy by the FSA.
13. We are ready to confront the manufacturers.