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1、第1章IsGMFoodSafeToEat?Traditionalplantbreedinginvolvescrossingvarietiesofthesamespeciesinwaystheycouldcrossnaturally.Forexample,disease-resistantvarietiesofwheathavebeencrossedwithhigh-yieldwheattocombinetheseproperties.Thistypeofnaturalgeneexchangeissafeandfairlypredictable.Geneticengineering(GE)inv
2、olvesexchanginggenesbetweenunrelatedspeciesthatcannotnaturallyexchangegeneswitheachother.GEcaninvolvetheexchangeofgenesbetweenvastlydifferentspeciese.g.puttingscorpiontoxingenesintomaizeorfishantifreezegenesintotomatoes.Itispossiblethatascorpiontoxingene,evenwhenitisinmaizeDNA1,willstillgettheorgani
3、smtoproducescorpiontoxinbutwhatothereffectsmayithaveinthisalienenvironment?Wearealreadyseeingthisproblemaddinghumangrowthhormonegenestopigscertainlymakesthemgrowbutitalsogivesthemarthritisandmakesthemcross-eyed,whichwasentirelyunpredictable.Itwillbeobvious,forexample,thatthegeneforhumanintelligencew
4、illnothavethesameeffectifinsertedintocabbageDNAasithadinhumanDNAbutwhatside-effectwouldithave?Inotherwords,isGMfood2safetoeat?Theansweristhatnobodyknowsbecauselong-termtestshavenotbeencarriedout.CompanieswantingaGMproductapprovedintheUKorUSAarerequiredtoprovideregulatorybodieswithresultsoftheirownsa
5、fetytests.Monsantos3soyabeanswereapparentlyfedtofishfor10weeksbeforebeingapproved.Therewasnorequirementforindependenttesting,forlong-termtesting,fortestingonhumansortestingforspecificdangerstochildrenorallergic4people.ThecurrentpositionoftheUKGovernmentisthatThereisnoevidenceoflong-termdangersfromGM
6、foods.IntheUS,theAmericanFoodandDrugAdministration5iscurrentlybeingprosecutedforcoveringupresearchthatsuggestedpossiblerisksfromGMfoods.第二章A consistent all-over tan may be impossible to achieve because some body areas are much more resistant to tanning than others, a study has found.Researchers - fu
7、nded by the Medical Research Council (MRC) - at the University of Edinburgh say the results explain why some holidaymakers find it so hard to achieve an even tan all over their body.The findings, published in the journal Experimental Dermatology, show that the buttock is much more resistant to sunsh
8、ine but surprisingly when it does go red it tans less well than other areas.It was also found that people with no freckles tanned more easily than those without freckling.The study represents the first time that the depth of a persons tan, and not just skin redness, has been quantified.Scientists ca
9、rried out the study to try and solve the puzzle of why different types of skin cancer tend to be found in different parts of the body, given that they are all caused by exposure to sunshine.The team aimed to identify whether this is linked to variations in the way different parts of the body develop
10、 a tan.The team analysed the skin of 100 volunteers, who were exposed to six dose of UVB on two areas of their body their back and their buttock.The volunteers were given an injection to minimise the rush of blood that naturally occurs after the skin is exposed to sunlight within the first 24 hours.
11、Researchers say this redness is often confused with the start of tanning, but in fact is the skins signal that it has been damaged.After seven days, the volunteers skin was analysed to find what colour remained after the redness had died down.This colour recognised as a suntan comes from the skins p
12、roduction of melanin, a defence that blocks the skin absorbing too much harmful UVB radiation.Jonathan Rees, Professor of Dermatology at the University of Edinburgh, who led the study said: One A consistent all-over tan may be impossible to achieve because some body areas are much more resistant to
13、tanning than others, a study has found.第三章New findings from the Monell Center reveal that weight gain of formula-fed infants is influenced by the type of formula the infant is consuming. The findings have implications related to the infants risk for the development of obesity, diabetes and other dis
14、eases later in life. Events early in life have long-term consequences on health and one of the most significant influences is early growth rate, said study lead author Julie Mennella, Ph.D., a developmental psychobiologist at Monell. We already know that formula-fed babies gain more weight than brea
15、st-fed babies. But we didnt know whether this was true for all types of formula.While most infant formulas are cows milk-based, other choices include soy-based and protein hydrolysate（水解物）-based formulas. Protein hydrolysate formulas contain pre-digested proteins and typically are fed to infants who cannot tolerate the intact（完整的，原封不动的） proteins in other formulas.In adults, pre-digested proteins are b
