经济学人》杂志原版英文TheEconomist整理版45.docx
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经济学人》杂志原版英文TheEconomist整理版45.docx
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经济学人》杂志原版英文TheEconomist整理版45
DigestOfThe.Economist.2006(4-5)
Hottotrot
AnewservicehopestodofortextingwhatSkypedidforvoicecalls
TALKischeap—particularlysincetheappearanceofvoice-over-internetservicessuchasSkype.Suchservices,whichmakepossibleverycheap(orevenfree)callsbyroutingpartorallofeachcallovertheinternet,haveforcedtraditionaltelecomsfirmstocuttheirprices.Andnowthesamethingcouldbeabouttohappentomobilephonetextmessages,followingthelaunchthisweekofHotxt,aBritishstart-up.
UsersdownloadtheHotxtsoftwaretotheirhandsets,justastheywouldagameoraringtone.Theychooseausername,andcanthenexchangeasmanymessagesastheylikewithotherHotxtusersfor£1($1.75)perweek.Themessagesaresentasdatapacketsacrosstheinternet,ratherthanbeingroutedthroughoperators'textmessaginginfrastructure.Asaresult,userspayonlyatinydata-transportcharge,typicallyofapennyorsopermessage.Sincetextmessagestypicallycost10p,thisisabigsaving—particularlyforthecost-consciousteenagersatwhomtheserviceisaimed.
MostteenagersinBritain,andelsewhereinEurope,payfortheirmobilephonesona“pre-paid”basis,ratherthanhavingamonthlycontractwitharegularbill.Pre-paidtariffsarefarmoreexpensive:
bundlesoffreetextsandotherspecialdeals,whichcanreducethecostoftextmessaging,aregenerallynotavailable.Forateenagerwhosendssevenmessagesaday,Hotxtcancutthecostoftextingby75%,saving£210peryear,saysDougRichard,thefirm'sco-founder.Forreallyintensivetext-messagers,thesavingscouldbeevenbigger:
JoshDhaliwalofmobileYouth,amarket-researchfirm,saysthatsometeenagers—chieflyboysaged15-16andgirlsaged14-15—are“supertexters”whosendasmanyas50messagesperday.
Whilethissoundslikegoodnewsforusers,itcouldprovepainfulformobileoperators.Text-messagingaccountsforaround20%ofatypicaloperator'srevenues.Withmarginsontextmessagesinexcessof90%,textingalsoaccountsfornearlyhalfofanoperator'sprofits.MrRichardisconfidentthatthereisnolegalwaythatoperatorscanblockhisservice;theycouldraisedata-transportcosts,butthatwouldunderminetheirowneffortstopushnewservices.Hotxtplanstolaunchinothercountriessoon.
“Thechallengeisgettingthatinitialmomentum,”saysMrDhaliwal.Hotxtneedstopersuadepeopletosignup,sothattheywillpersuadetheirfriendstosignup,andsoon.UnlikeSkype,Hotxtisnotfree,sousersmaybelessinclinedtogiveitatry.ButasSkypehasalsoshown,onceadisruptive,low-costcommunicationsservicestartstospread,itcanquicklybecomeverybigindeed.Andthatinturncanleadtolowerprices,notjustforitsusers,butforeveryone.
Adiscerningview
AnewwayofprocessingX-raysgivesmuchclearerimages
X-RAYSarethemysteriousphenomenonforwhichWilhelmRöntgenwasawardedthefirstNobelprizeinphysics,in1901.Sincethen,theyhaveshedtheirmysteryandfoundwidespreaduseinmedicineandindustry,wheretheyareusedtoreveal
theinnerpropertiesofsolidbodies.
Someproperties,however,aremoreeasilydiscernedthanothers.ConventionalXrayimagingreliesonthefactthatdifferentmaterialsabsorbtheradiationtodifferentdegrees.Inamedicalcontext,forexample,bonesabsorbX-raysreadily,andsoshowupwhiteonanX-radiograph,whichisaphotographicnegative.ButXraysarelessgoodatdiscriminatingbetweendifferentformsofsofttissue,suchasmuscles,tendons,fatandbloodvessels.That,however,couldsoonchange.ForFranzPfeifferofthePaulScherrerInstituteinVilligen,Switzerland,andhiscolleaguesreport,intheAprileditionofNaturePhysics,thattheyhavemanipulatedstandardX-rayimagingtechniquestoshowmanymoredetailsoftheinnerbody.
Thetrickneededtodiscernthisfinedetail,accordingtoDrPfeiffer,isasimpleone.TheresearcherstookadvantagenotonlyofhowtissuesabsorbX-raysbutalsoofhowmuchtheyslowtheirpassage.Thisslowingcanbeseenaschangesinthephaseoftheradiationthatemerges—inotherwordsoftherelativepositionsofthepeaksandtroughsofthewavesofwhichX-raysarecomposed.
Subtlechangesinphaseareeasilypickedup,sodoctorscandetectevensmallvariationsinthecompositionofthetissueunderinvestigation,suchasmightbecausedbytheearlystagesofbreastcancer.Indeed,thistrick—knownasphase-contrastimaging—isalreadyusedroutinelyinopticalmicroscopyandtransmissionelectronmicroscopy.Untilnow,however,noonehadthoughttouseitformedicalX-radiography.
Toperformtheirtrick,theresearchersusedaseriesofthreedevicescalledtransmissiongratings.TheyplacedonebetweenthesourceoftheX-raysandthebodyunderexamination,andtwobetweenthebodyandtheX-raydetectorthatformstheimage.ThefirstgratinggathersinformationonthephasesoftheX-rayspassingthroughit.Thesecondandthirdworktogethertoproducethedetailedphase-contrastedimage.Theapproachgeneratestwoseparateimages—theclassicX-rayimageandthephase-contrastedimage—whichcanthenbecombinedtoproduceahigh-resolutionpicture.
TheresearcherstestedtheirtechniqueonaCardinaltetra,atinyiridescentfishcommonlyfoundinfishtanksandaquariums.TheconventionalX-rayimageshowedthebonesandthegutofthefish,whilethephase-contrastedimageshoweddetailsofthefins,theearandtheeye.
DrPfeiffer'stechniquewouldthusappeartoofferawaytogetmuchgreaterdetailforthesameamountofradiationexposure.Moreover,sinceitusesstandardhospitalequipment,itshouldbeeasytointroduceintomedicalpractice.X-raysmaynolongerbethestuffofNobelprizes,buttheirusefulnessmayjusthaveincreasedsignificantly.
Herebedragons
Withluck,youmaysoonbeabletobuyamythologicalpet
PAOLOFRIL,chairmanandchiefscientificofficerofGeneDupe,basedinSanMelito,California,isamanwithadream.Thatdreamisadragonineveryhome.
GeneDupe'sbusinessisbiotechpets.NotforDrFril,though,themundanecloningofdeadmoggiesandpooches.Heplansarangeofentirelynewanimals—or,rather,ofreallyquiteoldanimals,withthetwistthatevenwhentheydidexist,itwasonlyintheimagination.
Makingamythicalcreaturerealisnoteasy.ButGeneDupe'steamofbiologistsandcomputerscientistsreckontheyareequaltothetask.Theirsecretisanewfield,whichtheycall“virtualcellbiology”.
Biologyandcomputinghavealotincommon,sincebothareaboutprocessinginformation—inonecaseelectronic;intheother,biochemical.Virtualcellbiologyaspirestomakeasoftwaremodelofacellthatisaccurateineverybiochemicaldetail.Thatispossiblebecauseallanimalcellsusethesamepartslist—mitochondriaforenergyprocessing,theendoplasmicreticulumformakingproteins,Golgibodyforproteinassembly,andsoon.
Armedwiththeirvirtualcell,GeneDupe'sscientistscancustomisetheresultsothatitbelongstoaparticularspecies,byloadingitwithavirtualcopyofthatanimal'sgenome.Then,ifthecellisalsoloadedwiththerightvirtualmolecules,itwillbehavelikeafertilisedegg,andstartdividinganddeveloping—firstintoanembryo,andultimatelyintoanadult.
Becausethis“growth”isgoingoninacomputer,ithappensfast.PassingfromeggtoadultinoneofGeneDupe'senormousMythmakercomputerstakeslessthanaminute.AnditisherethatCharlesDarwingetsalookin.Withsuchashortgenerationtime,GeneDupe'sscientistscanaddalittleevolutiontotheirproducts.
Eachcomputerstartswithasearchimage(dragon,unicorn,gryphon,etc),andthegenomeoftherealanimalmostcloselyresemblingit(alizardforthedragon,ahorsefortheunicornand,mosttaxingly,thesplicedgenomesofalionandaneagleforthegryphon).Thevirtualgenomesoftheserealanimalsarethentweakedbyrandomelectronicmutations.Whentheyhavematured,thevirtualadultsmostcloselyresemblingthetargetsarepickedandcross-bred,whiletheothersareculled.
Usingthisrapidevolutionaryprocess,GeneDupe'sscientistshavearrivedatgenomesforarangeofmythologicalcreatures—inacomputer,atleast.Thenextstage,onwhichtheyarejustembarking,istodoitforreal.
Thisinvolvessynthesising,withactualDNA,thegeneticmaterialthatthecomputermodelspredictwillproducethemythicalcreatures.ThesyntheticDNAistheninsertedintoacellthathashaditsnaturalnucleusremoved.Theresult,DrFrilandhiscommercialbackershope,willbeareallivedragon,unicornorwhathaveyou.
Talesoftheunexpected
Whyadrugtrialwentsobadlywrong
INANYsortoftest,notleastadrugstrial,oneshouldexpecttheunexpected.Evenso,onMarch13th,sixvolunteerstakingpartinasmallclinicaltrialofatreatmentknownasTGN1412gotfarmorethantheybargainedfor.Allendedupseriouslyill,withmultipleorganfailure,soonafterbeinginjectedwiththedrugataspecialtestingunitatNorthwickParkHospitalinLondon,runbyacompanycalledParexel.Onemanremainsillinhospital.
Small,preliminarytrialsofthissortareintendedtofindoutwhetheradrugistoxic.Nevertheless,themishapwassoseriousthatBritain'sMedicinesandHealthcareproductsRegulatoryAgency(MHRA),agovernmentbody,swiftlylaunchedafullinquiry.OnApril5thitannounceditspreliminaryfindings.Thesewerethatthetrialwasruncorrectly,dosesofthedrugweregivenastheyweresupposedtohavebeen,andtherewasnocontaminationduringmanufacturing.Inotherwords,itseemsthatdespiteextensivetestsonanimalsandhuman-cellcultures,anddespitethefactth
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