Chapter 2Bc science 10 Chapter 2(加拿大bc省科学十年级词汇)

合集下载

science10

Cellular activity and signaling induced by osteoprotegerin in osteoclasts:involvement of receptor activator of nuclearfactor n B ligand and MAPKS.Theoleyre a,1,Y .Wittrant a,1,S.Couillaud a ,P.Vusio b ,M.Berreur a ,C.Dunstan c ,F.Blanchard a ,F.Re´dini a ,D.Heymann a,*aEE 99-01,Pathophysiology of Bone Resorption Laboratory and Therapy of Primitive Bone Tumors,Medicine Faculty,1rue G.Veil,44035Nantes cedex 01,FrancebIFR 26,Institut de Biologie,Nantes Hospital,FrancecAmgen Inc.,One Amgen Center Drive,Thousand Oaks,CA 91320,USA Received 22July 2003;received in revised form 19September 2003;accepted 15October 2003AbstractOsteoprotegerin (OPG)is a decoy receptor for receptor activator of nuclear factor n B ligand (RANKL),an inducer of osteoclastogenesis via its receptor RANK.We recently demonstrated that OPG also exerts a direct effect in osteoclasts by regulating protease expression.Herein,we showed that OPG-induced pro-matrix metalloproteinase-9activity was abolished by ras/MAPK inhibitors in purified osteoclasts.OPG induced the phosphorylation of p38and ERK1/2in RAW264.7cells.Only p38activation was totally abolished by a blocking anti-RANKL antibody or an excess of RANKL.Surface plasmon resonance experiments revealed that RANK,RANKL and OPG are able to form a tertiary complex.These results suggested a potential formation of a tertiary complex RANK–RANKL–OPG on osteoclasts.Thus,OPG is not only a soluble decoy receptor for RANKL but must be also considered as a direct effector of osteoclast functions.D 2003Elsevier B.V .All rights reseved.Keywords:Osteoprotegerin;RANKL;Osteoclast;Metalloproteinase;Signaling1.IntroductionAmong the cellular and molecular parameters involved in the bone resorption process [1–3],receptor activator of nuclear factor n B ligand (RANKL),a member of the tumor necrosis factor family is the main regulator of osteoclast differentiation [4,5].Within the bone system,soluble and membrane forms of RANKL expressed by osteoblasts exert their activities through binding to their receptor RANK on osteoclasts [6,7].The third protagonist,osteoprotegerin (OPG)produced by osteoblasts acts as a decoy receptor for RANKL,preventing it from binding to and activatingRANK [8].It also inhibits the development of osteoclasts [9]and down-regulates the RANKL signaling through RANK [8].The biological effects of OPG on bone cells include the inhibition of terminal stages of osteoclast differentiation,suppression of mature osteoclast activation,and induction of apoptosis [7–9].We recently demonstrated that OPG can also exert a direct biological effect in osteoclasts by inducing proteases and protease inhibitors expression suggesting a more com-plex regulation of bone resorption by OPG than originally described [10].These results are consistent with those obtained by Hakeda et al.[11]who reported a direct effect of OPG on isolated osteoclasts via a 140kDa OPG-binding protein on cell membrane.Whereas OPG exhibits no transmembrane domain,Yun et al.[12]reported the pres-ence of a membrane-bound form of OPG in dendritic cells that may correspond to either a matrix-bound or/and a transmembrane form of the protein.More recently,Standal et al.presented evidence that myeloma cells internalize and0167-4889/$-see front matter D 2003Elsevier B.V .All rights reseved.doi:10.1016/j.bbamcr.2003.10.005*Corresponding author.Tel.:+33-2-4041-2845;fax:+33-2-4041-2860.E-mail address:dominique.heymann@sante.univ-nantes.fr (D.Heymann).1Equally contributed to the Biochimica et Biophysica Acta 1644(2004)1–7degrade OPG through its binding to syndecan-1,the major heparan sulfate proteoglycan expressed on myeloma cells [13].OPG possesses a highly basic heparin-binding domain, making interactions with heparin and heparan sulfates possible,suggesting a new control mechanism for OPG biological activity[14].The purpose of the present study was(i)to further investigate the direct biological effect of OPG on osteoclasts and the signaling pathways associated,(ii)to better charac-terize the receptor(s)involved.2.Experimental procedures2.1.Cell culture2.1.1.Purified osteoclast preparationPurified osteoclasts(purity95%)were obtained from neonatal rabbit bone cells isolated using a previously reported method[15].After purification,the osteoclasts were cultured in serum-free a-MEM for24h in the absence or presence of 50ng/ml human OPG(Amgen Inc.,Thousand Oaks,USA). In some experiments,before addition of OPG,cells were also preincubated for1h in the presence of signaling pathway inhibitors:PI3kinase(Wortmannin:500nM),tyrosine kinase(Genistein:200A M)(Saint Quentin Fallavier,France), protein kinase A(PKI5–24:100nM),PKC and cAMP-dependent protein kinase(H7dihydrochloride:100A M), MAPK extracellular signaling-regulated kinase(ERK)ki-nase(MEK)(PD98059:40A M),Ras(FPT inhibitor II (FPTII):40A M)and p38MAPK(SB203580:0.1,10A M) (Calbiochem,La Jolla,USA).Equivalent dilutions of DMSO (reconstitution solution)alone served as control.A dose–response of the different inhibitors was tested previously and the optimal doses were used in this study.The RAW264.7cells obtained from Prof.Matsumoto (Saitama,Japan)were maintained in a-MEM without red phenol supplemented with10%FBS and differentiated in the presence of50ng/ml human RANKL(Amgen)for10 days.Cells were then cultured in serum-free medium for24 h and incubated for5min in the presence or absence of50 ng/ml RANKL or OPG,with or without4A g/ml anti-human RANKL antibody(R&D System,Abington,UK).In some cases,after serum-free culture period,cells were treated with 50ng/ml RANKL for2h,washed or not before incubation with the combinations described above.The293cells transfected with the full-length cDNA coding for murine RANKL(293-RANKL cells)were a generous gift of Dr.R.Josien(INSERM U437,Nantes, France)and were cultured in DMEM supplemented with 10%FBS.2.1.2.Measurement of matrix metalloproteinase activitiesAfter3days of culture in a-MEM supplemented with10% FBS,purified osteoclasts were cultured for24h in serum-free a-MEM in the presence or absence of50ng/ml OPG.Matrix metalloproteinase(MMP)activities were then detected in cell culture supernatants by gelatin zymography as previously described[15].After the culture period(24h in serum-free a-MEM in the presence or absence of OPG),MMP activities were detected in cell culture supernatants.Electrophoresis gel was composed of10%polyacrylamide gel containing0.2% gelatin.Proteinase activity was apparent as unstained regions.The stained polyacrylamide gels were observed with a video camera that allowed transfer to software for image processing(ImageQuant software program)and isolation of migration bands.Gelatinase activity was expressed as a percentage(shades of grey compared to the control).The same experiment was performed by adding10A M EDTA,a chelating agent of bivalent ions,to inhibit MMP activities.In addition,as protein levels were not modified by the different treatments,the same volume of supernatant was assayed in all experiments,allowing strict comparison of the results.2.1.3.Semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR)Total RNA for cDNA synthesis was isolated from RAW264.7cells and293-RANKL cells by phenol–chloro-form extraction as previously described[12].RT-PCR assays were carried out using the following primer pairs for RANKL (5V-CAGCATCGCTCTGTTCCTGTA-3(sense),5V-TCTCAGTCTATGCCTGAACTTTGAAAGC-3V(anti-sense));RANK(5V-AAGATGGTTCCAGAAGACGGT-3V (sense),5V-CATAGAGTCAGTTCTGCTCGGA-3V); MMP-9(5V-TCTGAGGCCTCTACAGAGTCT-3V(sense), 5V-CTCATGGTCCACCTTGTTCAC-3V(antisense))and 18S(5V-TCAAGAACGAAAGTCGGAGGTTCG-3V (sense)and5V-TTATTGCTCAATCTCGGGTGGCTG-3V (antisense)).2.1.4.Western blot studies and signal transductionRAW264.7cells were lysed in ice-cold lysis buffer(NaCl 150mM,Tris50mM,Nonidet P-401%,sodium deoxy-cholate0.25%,NaF1mM,NaVO41mM,leupeptine10A g/ ml,aprotinin10A g/ml,phenymethylsulfonylfluoride0.5 mM,glycerol10%).Equal amounts of proteins were re-solved on10%SDS-PAGE,and transferred to a PVDF membrane.After two washes in0.05%Tween20/PBS,the membrane was incubated in a saturating solution(0.05% Tween20/3%BSA/PBS)for30min,the levels of phos-phorylated ERK1/2and p38were detected with specific antibodies(Ozyme Saint-Quentin en Yvelines,France)as well as total ERK1/2and p38(R&D System).2.1.5.Surface plasmon resonance studiesThese experiments were performed with the BIACore 2000optical biosensor(BIACore,Uppsala,Sweden).Solu-ble human RANK(sRANK)(Promocell,Heidelberg,Ger-many)was covalently coupled through its primary amino groups to a carboxymethyl dextran flow cell(CM5,BIA-Core)as recommended by the manufacturer.All binding experiments were performed at a flow rate of10A l/min.TheS.Theoleyre et al./Biochimica et Biophysica Acta1644(2004)1–7 2resonance signal measured on the control flow cell was subtracted from the signal measured on the experimental flow cell.The resulting sensorgrams were analyzed using the BIAEvaluation software(BIACore).2.1.6.Statistical analysisThe mean F S.D.was calculated for all conditions and compared by ANOVA.Differences relative to a probability of two-tailed P<0.05were considered significant.3.Results3.1.OPG enhances proMMP-9activity of purified osteo-clasts by the ras/MAPK pathwayTo determine the signaling pathways by which OPG exerts its effects on osteoclasts,the modulation of OPG-induced proMMP-9activities was studied in the presence of specific inhibitors of different intracellular signaling path-ways.Tyrosine kinase inhibitor(Genistein),PKC and cAMP-dependent protein kinase inhibitor(H7)and Ras inhibitor(FPT inhibitor II)completely abolished OPG-induced stimulation of proMMP-9(Fig.1A).Conversely, PI3kinase inhibitor(Wortmannin)and protein kinase A inhibitor(PKI5–24)did not prevent OPG effects(data not shown).In this context,two synthetic MAPK inhibitors (SB203580and PD98505inhibitors of p38and MEK, respectively)have been studied(Fig.1B).Thus,pretreat-ment with SB203580inhibited the OPG-induced proMMP-9activity in a dose-dependent manner.Similarly,40A M of PD98059completely abolished the OPG-induced proMMP-9activity.Both inhibitors did not affect pro-MMP-9activity of non-stimulated osteoclasts(not shown).These results demonstrated that the ras/MAPK signaling is required for OPG to stimulate osteoclast proMMP-9activity.3.2.OPG induces phosphorylation of ERK1/2and p38indifferentiated RAW264.7cellsTo further explore the MAPK involvement in cellular activities induced by OPG on osteoclasts,we employed the RAW264.7cells.Indeed,this cell line is known to express RANK and differentiate into tartrate-resistant acid phospha-tase(TRAP)and calcitonin receptor-positive cells when cultured in the presence of RANKL[16].Moreover,the large amounts of cellular materials obtained from RAW264.7cell cultures allow to perform signal transduc-tion studies which were impossible on purified osteoclasts. RAW264.7cells were differentiated in the presence of RANKL for10days and then RANKL-and serum-de-prived for24h.OPG signaling studies were then monitored on by Western blot analyses using phosphospecific anti-bodies.Interestingly,treatment with50ng/ml OPG caused phosphorylation of ERK1/2(Fig.2A)and p38(Fig.2B) detectable within2min,whereas total ERK1/2and p38were unchanged.The phosphorylation of ERK1/2induced by OPG reached maximum after5–10min and thereafter gradually slightly decreased(Fig.2A).The phosphorylation of p38reached maximum after10min(Fig.2B).We confirmed that differentiated RAW264.7cells expressed RANK(Fig.3A,lane3)but not RANKL(Fig.3A,lane 2)mRNA transcripts as compared to a positive control (293-RANKL cells,Fig.3A,lane1).Since RANKL is known to activate similar signaling pathways[16,17],we conducted same experiments in the presence of RANKL and confirmed the ability of RANKL to induce both ERK1/ 2and p38MAPKs activation in RAW264.7cells(Fig.3B, lane3compared to the control lane1).Since(i)OPG was classically described as one of the ligands for RANKL and (ii)RAW264.7cells have been differentiated in the pres-ence of50ng/ml of soluble RANKL,similar experiments were performed in the presence of anti-RANKL antibody, to test the hypothesis that OPG could act on osteoclastsvia Fig. 1.Inhibition of OPG-induced proMMP-9activity on purified osteoclasts by ras/MAPK inhibitors.Purified osteoclasts were cultured in the absence or presence of50ng/ml OPG,in association or not with different signaling pathway inhibitors:Genistein200A M(tyrosine kinase inhibitor),H7100A M(PKC-and cAMP-dependent protein kinase inhibitor),FPTII40A M(Ras inhibitor)(A)or PD9805940A M(MEK inhibitor),SB2035800.1and10A M(p38inhibitor)(B).Metalloproteinase activity was determined using a gelatin zymographic assay.Results are the mean F S.D.of five separate cultures tested.**P<0.001***P<0.0001 compared to OPG alone,#P<0.05compared to the untreated control.S.Theoleyre et al./Biochimica et Biophysica Acta1644(2004)1–73RANKL.Anti-RANKL antibody totally abolished the OPG-induced phosphorylation of p38but only slightly inhibited the activation of ERK1/2(Fig.3B ,lane 4com-pared to the OPG condition lane 2).To elucidate the role of RANKL in OPG-induced biological activity,p38activation was monitored on differentiated RAW264.7cells that were RANKL-and serum-deprived for 24h and then further treated with RANKL for 2h.In the first approaches,exten-sive washing were done before signaling analysis to remove free RANKL excess but potentially not specific RANKL bound to membrane RANK.When the RAW264.7cells are not rinsed,the excess of free RANKL abolished the OPG-induced p38phosphorylation (Fig.3C ,lanes 1and 2).This OPG-induced p38activation persisted when free RANKL was removed before OPG treatment (cell cultures washed)(Fig.3C ,lane 3compared to the control lane 1)and was totally inhibited by the addition of blocking anti-RANKL antibody (Fig.3C ,lane 4compared to the OPG condition lane 3).Biological activity of OPG on MMP-9expression was also totally abolished in the presence of blocking anti-RANKL antibody (data not shown).These overall results showed that OPG exerts a cellular activity dependent on the presence of RANKL associated with osteoclasts,demon-strating that OPG is not only a soluble decoy receptor for RANKL as described in the literature [4].3.3.OPG,RANKL and RANK are able to form a hetero-molecular complexAs the above results demonstrated,a biological effect of OPG on osteoclasts,dependent on the presence of RANKL,and as RANKL is the natural ligand of RANK [7],we wondered whether OPG could bind to the complex RANKL–RANK present at the osteoclast membrane.Weinvestigated the molecular interactions between OPG,RANKL and RANK by surface plasmon resonance tech-nique.We confirmed that RANKL bound to immobilized RANK (Fig.4A,B).Analyses of the kinetic association and dissociation curves allowed the calculation of the dissociation constant K d =2.05nM.While OPG did not bind to immobi-lized RANK (Fig.4B),it bound to the preformed RANKL–RANK complex with a K d =5.2nM (Fig.4A),thenconsti-Fig.3.OPG-induced phosphorylation of ERK1/2but not p38is dependent on RANKL in RAW264.7cells.(A)RT-PCR analyses of RANK,RANKL and 18S message levels were performed in RAW264.7cells and in 293-RANKL cells.RNA were isolated from RAW264.7cells differentiated 10days in the presence of 50ng/ml ne 1:RT-PCR reaction for RANKL on a positive control (293-RANKL cells);RT-PCR reactions on RAW264.7cells for RANKL (lane 2)and for RANK (lane 3).(B)ERK1/2and p38phosphorylation was analyzed on differentiated RAW264.7cells treated for 10min with 50ng/ml RANKL or OPG in the presence or absence of 4A g/ml blocking anti-RANKL antibody.(C)The OPG-induced p38activation was analyzed in the presence of absence of free RANKL excess and blocking anti-RANKL antibody.Cell lysates were also subjected to Western blot analysis with anti-ERK1/2and/or anti-p38antibodies to demonstrate equal loading (B andC).Fig.2.OPG induced phosphorylation of ERK1/2and p38in RAW264.7cells.RAW264.7cells were treated with 50ng/ml OPG and collected after the indicated time,followed by immunoblotting using anti-phospho-ERK1/2(A)or -p38(B).Cell lysates were also subjected to Western blot analysis with anti-ERK1/2and anti-p38antibodies to demonstrate equal loading.S.Theoleyre et al./Biochimica et Biophysica Acta 1644(2004)1–74tuting a tertiary complex OPG–RANKL–RANK (Fig.4C).Moreover,the preincubation of OPG with RANKL abolished the capability of RANKL to further bind to immobilized RANK (Fig.4B),confirming the role of decoy receptor for OPG described in the literature.These results allow to explain the OPG biological activity on osteoclasts through the for-mation of a tertiary complex OPG–RANKL–RANK.4.DiscussionThe molecular triad OPG–RANKL–RANK play a piv-otal role in bone resorption regulation [7,9].The results of the present study demonstrate for the first time,that in addition to be a decoy receptor for RANKL,OPG also induces ras-MAPK activation on osteoclasts.Moreover,the OPG-induced phosphorylations on osteoclast-like cells are dependent on RANKL bound to the cell membrane,and OPG–RANKL–RANK can constitute a hetero-molecular complex as demonstrated by surface plasmon resonance technique.First evidence of an OPG binding on eucaryote cells was given by Kwon et al.[18].These authors identified a new molecule named TNF receptor-like molecule 1(TR1)which exerted direct biological activities including osteoclasto-genesis inhibition and fibroblast proliferation.In fact,this molecule is identical to OPG.Scatchard analyses showed two classes of high and medium affinity receptors for TR1with kD of approximately 45and 320pM.More recently,three different isoforms of the OPG-ligand,RANKL were expressed in osteoblastic cells,two of them as transmem-brane molecules and the third one,as a soluble protein [19].If the expression of membrane-associated RANKL may represent the specific high affinity ‘‘receptor’’for OPG reported by Kwon et al.,the medium affinity receptors need to be further characterized.Standal et al.[13]reported that OPG can bind to heparan sulfate proteoglycans in myeloma cells,evidencing a new potential binding molecule for OPG.Proteoglycans have already been shown to mediate the binding and the internalization of several extracellular ligands [20]with affinity binding compatible to those observed for TR1[18].Other experiments performed by Reiland et al.[21]demonstrated that pervanadate activates intracellular kinases leading to tyrosine phosphorylation of syndecan-1.It has been proposed that cell surface proteo-glycans as syndecans exert putative functions as growth factor co-receptors,influencing the activation of various tyrosine kinase receptor [22].In light of the above data,it can be suggested that OPG binds to membrane RANKL and/or to cell surface heparan sulfate proteoglycans.However,the mechanisms by which OPG exerts its biological activity as well as the nature of its molecular interactions with osteoclasts are not well defined.Hakeda et al.[11]reported the first evidence of a direct biological activity of OPG on isolated osteoclasts via a 140kDa OPG-binding protein.The exact nature of OPG receptors on osteoclasts was not further characterized but RANKL,as one putative OPG receptor has been evinced since it is not expressed by osteoclasts.However,the production of RANKL by contaminating stromal cells cannot be exclud-ed.Direct biological activities of OPG on osteoclasts were recently confirmed by Wittrant et al.[10]who demonstrat-ed that in purified osteoclasts,OPG enhanced proMMP-9activity among several other parameters (TRAP,TIMP,cathepsin K).The present study reveals that OPGstim-Fig.4.Formation of a hetero-molecular complex between RANK,RANKL,and OPG studied by surface plasmon resonance experiments.Binding of 250nM (7.75A g/ml)(A)or 125nM (3.87A g/ml)(B)RANKL and 110nM (10A g/ml)OPG successively (A)or after pre-incubation for 1h at 37j C (B)to RANK was carried out.Schematic diagrams of RANK–RANKL–OPG molecular interactions is shown in (C).Trimer RANKL can bind to the trimer RANK expressed on the osteoclast cell membrane (left),then inducing specific signal transduction (arrow).Dimer OPG could interact on the RANKL–RANK complex to form a tertiary complex that could activate two different signal transduction pathways via this tertiary complex and an undermined molecule (?)(middle).OPG acts as a decoy receptor when it is preincubated with RANKL (right).S.Theoleyre et al./Biochimica et Biophysica Acta 1644(2004)1–75ulates proMMP-9activity of osteoclasts by the ras/MAPK pathway.RAW264.7cells differentiated in the presence of RANKL,express osteoclast markers(RANK,TRAP,calci-tonin receptor,cathepsin K)and allow to demonstrate the OPG-induced ERK1/2and p38phosphorylations.Although these cells did not express RANKL,blocking anti-RANKL antibody totally abolished p38activation and slightly re-duced ERK1/2activation,demonstrating OPG signaling pathways dependent on RANKL.RANKL has been already shown to induce specific signal transduction pathways in osteoclasts through its binding to membrane RANK,espe-cially p38[16,23]and ERK1/2[17,23].In the RAW264.7 cells,soluble RANKL used to induce osteoclastogenesis is bound to its receptor RANK present at the osteoclast cell surface and OPG may bind to the preformed complex RANKL–RANK,then re-inducing p38activation.The potential formation of a tertiary complex RANK–RANKL–OPG is supported by the results of the surface plasmon resonance studies,which revealed that OPG can bind to the preformed complex RANKL–RANK.These results allow to explain the direct OPG biological activity on purified osteoclasts and differentiated RAW264.7cells through the formation of a hetero-molecular complex OPG–RANKL–RANK(Fig.3C).However,the slight inhibition of OPG-ERK1/2activation by an anti-RANKL antibody suggests the potential existence of a second binding site which is still undetermined.In this context, proteoglycans such as syndecan-1that can be phosphory-lated by intracellular tyrosine kinase may be good candi-dates([21],Fig.4C).In addition,OPG-induced MMP-9 activity on purified osteoclasts is abolished by a tyrosine kinase inhibitor(Fig.1),reinforcing this hypothesis.Re-cently,Hotokezaka et al.[17]demonstrated that osteoclasto-genesis is regulated under a balance between ERK and p38 pathways.In their system,ERK pathway negatively regu-lates osteoclastogenesis while p38pathway is involved as a positive control.In our study,OPG-induced ERK1/2phos-phorylation independently of RANKL could strengthen the specific inhibitory activity of OPG on osteoclastogenesis via a similar balance[8].Thus,OPG induces MAPK phosphorylation via RANKL and acts as a decoy receptor.This dual function of OPG could depend on its association sequence of both molecules. Indeed,when OPG binds to RANKL before RANKL binding to membrane RANK,it acts as a decoy receptor (case of stromal cells which expressed membrane RANKL but not RANK or soluble form of RANKL).In the case where RANKL binds to RANK on osteoclast membrane before its interaction with OPG,OPG could form a hetero-tertiary complex on osteoclasts,therefore inducing MAPK phosphorylations.In conclusion,the present study demonstrated for the first time that OPG stimulates proMMP-9activity of osteoclasts via the ras/MAPK pathway involving p38and ERK1/2 phosphorylations.Moreover,OPG-induced MAPK pathway depends on RANKL.These data strengthened by the surface plasmon resonance analyses suggest the potential formation of a tertiary complex RANK–RANKL–OPG on osteo-clasts.These overall results demonstrated that OPG is not only a soluble decoy receptor for RANKL as described in the literature but must be also considered as a direct effector of osteoclast functions.AcknowledgementsThis work was supported by a CReS INSERM no. 4CR06F,by a grant from the French Ministry of Research and Technology(TS/0220044)and by a grant from the Loire-Atlantique Committee of the Ligue Contre le Cancer. S.The´oleyre and Y.Wittrant received,respectively,a fellowship from the Loire-Atlantique Committee of the Ligue Contre le Cancer and from the Re´gion of Pays de Loire.References[1] A.V.Rousselle,D.Heymann,Osteoclastic acidification pathways dur-ing bone resorption,Bone30(2002)533–540.[2]J.M.Delaisse´,G.Vaes,in:B.R.Rifkin,C.V.Gay(Eds.),Biology andPhysiology of Osteoclast,CRC Press,Boca Raton,1992,pp.289–314.[3] D.Heymann,J.Guicheux,F.Gouin,N.Passuti,G.Daculsi,Cyto-kines,growth factors and osteoclasts,Cytokine10(1998)155–168.[4] cey,E.Timms,H.L.Tan,M.J.Kelley,C.R.Dunstan,T.Bur-gess,R.Elliott,A.Colombero,G.Elliott,S.Scully,H.Hsu,J.Sulli-van,N.Hawkins,E.Davy,C.Capparelli,A.Eli,Y.X.Qian,S.Kaufman,I.Sarosi,V.Shalhoub,G.Senaldi,J.Guo,J.Delaney, W.J.Boyle,Osteoprotegerin ligand is a cytokine that regulates osteo-clast differentiation and activation,Cell93(1998)165–176.[5]H.Yasuda,N.Shima,N.Nakagawa,K.Yamaguchi,M.Kinosaki,S.Mochizuki,A.Tomoyasu,K.Yano,M.Goto,A.Murakami,E.Tsuda, T.Morinaga,K.Higashio,N.Udagawa,N.Takahashi,T.Suda,Os-teoclast differentiation factor is a ligand for osteoprotegerin/osteoclas-togenesis-inhibitory factor and is identical to TRANCE/RANKL, Proc.Natl.Acad.Sci.U.S.A.95(1998)7–3607.[6]H.Hsu,cey,C.R.Dunstan,I.Solovyev,A.Colombero,E.Timms,H.L.Tan,G.Elliott,M.J.Kelley,I.Sarosi,L.Wang,X.Z.Xia,R.Elliott,L.Chiu,T.Black,S.Scully,C.Capparelli,S.Morony,G.Shimamoto,M.B.Bass,W.J.Boyle,Tumor necrosis factor recep-tor family member RANK mediates osteoclast differentiation and activation induced by osteoprotegerin ligand,Proc.Natl.Acad.Sci.U.S.A.96(1999)3540–3545.[7]L.E.Theill,W.J.Boyle,J.M.Penninger,RANK-L and RANK:T cells,bone loss,and mammalian evolution,Annu.Rev.Immunol.20(2002) 795–823.[8]W.S.Simonet,cey,C.R.Dunstan,M.Kelley,M.S.Chang,R.Luthy,H.Q.Nguyen,S.Wooden,L.Bennett,T.Boone,G.Shima-moto,M.DeRose,R.Elliott,A.Colombero,H.L.Tan,G.Trail,J.Davy,E.Davy,N.Bucay,L.Renshaw-Gegg,T.M.Hughes,D.Hill, W.Pattison,P.Campbell,S.Sander,G.Van,J.Tarpley,P.Derby,R.Lee,Amgen EST Program,W.J.Boyle,Osteoprotegerin:a novel secreted protein involved in the regulation of bone density,Cell89 (1997)309–319.[9] E.Grimaud,F.Re´dini,D.Heymann,Osteoprotegerin:a new agentfor the treatment of bone disease,Drug Discov.Today6(2002) 1241–1242.S.Theoleyre et al./Biochimica et Biophysica Acta1644(2004)1–7 6[10]Y.Wittrant,S.Couillaud,S.The´oleyre,C.Dunstan,D.Heymann,F.Re´dini,Osteoprotegerin differentially regulates protease expression in osteoclast cultures,mun.293(2002) 38–44.[11]Y.Hakeda,Y.Kobayashi,K.Yamaguchi,H.Yasuda,E.Tsuda,K.Higashio,T.Miyata,M.Kumegawa,Osteoclastogenesis inhibitory factor(OCIF)directly inhibits bone-resorbing activity of isolated ma-ture osteoclasts,mun.251(1998)796–801.[12]T.J.Yun,P.M.Chaudhary,G.L.Shu,J.K.Frazer,M.K.Ewings,S.M.Schwartz,V.Pascual,L.E.Hood,E.A.Clark,OPG/FDCR-1,a TNF receptor family member,is expressed in lymphoid cells and is up-regulated by ligating CD40,J.Immunol.161(1998)6113–6121. [13]T.Standal,C.Seidel,O.Hjertner,T.Plesner,R.D.Sanderson,A.Borset,M.Borset,A.Sundan,Osteoprotegerin is bound,internal-ized,and degraded by multiple myeloma cells,Blood100(2002) 3002–3007.[14]K.Yamaguchi,M.Kinosaki,M.Goto,F.Kobayashi,E.Tsuda,T.Morinaga,K.Higashio,Characterization of structural domains of human osteoclastogenesis inhibitory factor,J.Biol.Chem.273 (1998)5117–5123.[15] A.V.Rousselle,C.Damiens,Y.Fortun,N.Passuti,M.Padrines,D.Heymann,Human growth hormone stimulates proteinase activities of rabbit bone cells via IGF-I,mun.268 (2000)875–881.[16]M.Matsumoto,T.Sudo,T.Saito,H.Osada,M.Tsujimoto,Involve-ment of p38mitogen-activated protein kinase signaling pathway in osteoclastogenesis mediated by receptor activator of NF-kappa B li-gand(RANKL),J.Biol.Chem.275(2000)31155–31161.[17]H.Hotokezaka,E.Sakai,K.Kanaoka,K.Saito,K.Matsuo,H.Yosh-ida,N.Yoshida,K.Nakayama,U0126and PD98059,specific inhib-itors of MEK,accelerate differentiation of RAW264.7cells into osteoclast-like cells,J.Biol.Chem.277(2002)47366–47372. [18] B.S.Kwon,S.Wang,N.Udagawa,V.Haridas,Z.H.Lee,K.K.Kim,K.O.Oh,J.Greene,Y.Li,J.Su,R.Gentz,B.B.Aggarwal,J.Ni,TR1,a new member of the tumor necrosis factor receptor superfamily,induces fibroblast proliferation and inhibits osteoclastogenesis and bone resorption,FASEB J.12(1998)845–854.[19]T.Ikeda,M.Kasai,M.Utsuyama,K.Hirokawa,Determination ofthree isoforms of the receptor activator of nuclear factor-kappaB li-gand and their differential expression in bone and thymus,Endocri-nology142(2001)1419–1426.[20]M.Roghani,D.Moscatelli,Basic fibroblast growth factor is internal-ized through both receptor-mediated and heparan sulfate-mediated mechanisms,J.Biol.Chem.267(1992)22156–22162.[21]J.Reiland,V.L.Ott,C.S.Lebakken,C.Yeaman,J.McCarthy,A.C.Rapraeger,Pervanadate activation of intracellular kinases leads to tyrosine phosphorylation and shedding of syndecan-1,Biochem.J.319(1996)39–47.[22]M.Bernfield,R.Kokenyesi,M.Kato,M.T.Hinkes,J.Spring,R.L.Lose,E.J.Lose,Biology of the syndecans:a family of transmem-brane heparan sulfate proteoglycans,Annu.Rev.Cell Biol.8(1992) 365–393.[23]S.E.Lee,K.M.Woo,S.Y.Kim,H.M.Kim,K.Kwack,Z.H.Lee,H.H.Kim,The phosphatidylinositol3-kinase,p38and extracellular signal-regulated kinase pathways are involved in osteoclast differentiation, Bone30(2002)71–77.S.Theoleyre et al./Biochimica et Biophysica Acta1644(2004)1–77。

ChapterBc science 10 Chapter 3(加拿大bc省科学十年级词汇)

adaptive radiationthe development of a number of new species from a common ancestor; the new species are adapted to inhabit different nichesaerationmixing with air; one method to reduce run-off is to mechanically remove small plugs of soil to improve air and water flow through the soilbioremediationthe act of treating waste or pollutants by the use of microorganisms (as bacteria) or plants that can break down the undesirable substances such as chemical pollutants to reverse or lessen environmental damageclimax communitya mature community, such as a boreal forest, tropical rainforest, grassland, or desert, that continues to change over timedeforestationthe clearing or logging of forests without replantingecological successionchanges that take place over time in the types of organisms that live in an areaextinctionthe dying out of a species; species become extinct when their numbers are reduced to zeroforeign speciesintroduced specieshabitat fragmentationsplitting of ecosystems into small fragmentshabitat lossthe destruction of habitats that usually results from human activitiesintroduced speciesspecies moved to new geographic areas, either intentionally or accidentallyinvasive speciesintroduced organisms that can take over the habitats of native species or invade their bodies thus weakening their immune systemland usethe ways in which we use land, such as for urban development, agriculture, industry, mining andforestrynative speciesplants and animals that naturally inhabit an areanatural selectionthe process in which, over time, the best-adapted members of a species will survive and reproduce. This process makes change in living things possible.overexploitationthe use or extraction of a resource until it is depletedpioneer speciesfirst species to populate an area during primary succession; these organisms change the abiotic and biotic conditions of an area so that other organisms can survive thereprimary successionthe development of new life in areas where no organisms or soil previously existed, such as on bare rock; the first organisms may be lichen spores carried by windsresource exploitationresource userecourse usethe ways in which we obtain and use naturally occurring materials such as soil, wood, water, gas, oil, or mineralssecondary successionthe reintroduction of life after a disturbance to an area that already has soil and was once the home of living organismssoil compactionthe squeezing together of soil particles so that the air spaces between them are reducedsoil degradationdamage to soil - for example, as a result of deforestation or the removal of topsoil from bare land by water and wind erosiontraditional ecological knowledgeecological information, passed down from generation to generation, that reflects human experience with nature gained over centuriessustainabilityThe ability of an ecosystem to sustain ecological processes and maintain biodiversity over time;using natural resources in a way that maintains ecosystem health now and for future generations.contaminationthe introduction of chemicals, toxins,wastes, or micro organisms into the environment in concentrations that are harmful to living things.。

剑桥学习科学手册(第一、二部分)

四、研究目标
（1）为了更好地理解认知过程和社会化过程以产生最有效的学习；（2）为了用学习科学的知识来重新设计我们的课堂和其他学习环境。
五、概念界定
研究多种情境下的学习（正式学习与非正式学习）；多学科、跨学科的新科学；为未来学校绘制发展蓝图。
本书目的：通过展示不同的人设计学习环境和课堂的方式，来建立新的学习科学。
了解对话的过程，即知识产生的过程；能够批判地检查论据的逻辑性
将陈述性知识和程序性知识视为静态知识，认为这些知识只来自于权威著作
要求学习者反思其理解及学习的过程
仅仅记忆知识，没有对目的和学习策略等进行反思
学习科学的基础
建构主义
认知科学
教育技术学
社会文化研究
学科知识研究
科学知识是情境性的、实践性的、通过协作产生的。
在认知分析中运用交互
群体活动分析可能会涉及个体活动中不明显的重要活动
可以将群体分解为单独个体的方式研究解释群体
从认知到交互
将认知原则从个人延伸到群体活动是相当有价值的
情景化视角
情境化方法的明确特征是不再关注个体学习者，分析的主要焦点在于活动系统：包含学习者、教师、课程材料、软件工具以及自然环境在内的复杂的社会组织。
监控问题解决活动获得产生式规则的过程
表征学生的多种策略和典型迷失概念
知识跟踪
模型跟踪
认知模型
工作机制
设计原则
以产生式规则集的形式展现学生的能力在问题——解决的情境中提供指导在问题解决之前传达目标结构促进对问题解决知识的正确、总体的理解将学习外部的工作记忆负荷减弱到最低程度对与预期绩效模型相关的错误提供即时反馈
内隐学习与大脑
对理解学习的个体差异提供帮助

研究生公共英语教材阅读B第3、4、10、11、14课文原文及翻译

Unite 3 Doctor’s Dilemma: Treat or Let Die?Abigail Trafford1. Medical advances in wonder drugs, daring surgical procedures, radiation therapies, and intensive-care units have brought new life to thousands of people. Yet to many of them, modern medicine has become a double-edged sword.2. Doctor’s power to treat with an array of space-age techniques has outstripped the body’s capacity to heal. More medical problems can be treated, but for many patients, there is little hope of recovery. Even the fundamental distinction between life and death has been blurred.3. Many Americans are caught in medical limbo, as was the South Korean boxer Duk Koo Kim, who was kept alive by artificial means after he had been knocked unconscious in a fight and his brain ceased to function. With the permission of his family, doctors in Las Vegas disconnected the life-support machines and death quickly followed.4. In the wake of technology’s advances in medicine, a heated debate is taking place in hospitals and nursing homes across the country --- over whether survival or quality of life is the paramount goal of medicine.5. “It gets down to what medicine is all about, ” says Daniel Callahan, director of the Institute of Society, Ethics, and the Life Sciences in Hastings-on-Hudson, New York. “Is it really to save a life? Or is the larger goal the welfare of the patient?”6. Doctors, patients, relatives, and often the courts are being forced to make hard choices in medicine. Most often it is at the two extremes of life that these difficultyethical questions arise --- at the beginning for the very sick newborn and at the end for the dying patient.7. The dilemma posed by modern medical technology has created the growing new discipline or bioethics. Many of the country’s 127 medical s chools now offer courses in medical ethics, a field virtually ignored only a decade ago. Many hospitals have chaplains, philosophers, psychiatrists, and social workers on the staff to help patients make crucial decisions, and one in twenty institutions has a special ethics committee to resolve difficult cases.Death and Dying8. Of all the patients in intensive-care units who are at risk of dying, some 20 percent present difficult ethical choices --- whether to keep trying to save the life or to pull back and let the patient die. In many units, decisions regarding life-sustaining care are made about three times a week.9. Even the definition of death has been changed. Now that the heart-lung machine can take over the functions of breathing and pumping blood, death no longer always comes with the patient’s “last gasp” or when the heart stops beating. Thirty-one states and the District of Columbia have passed brain-death statutes that identify death as when the whole brain ceases to function.10. More than a do zen states recognize “living wills” in which the patients leave instructions to doctors not to prolong life by feeding them intravenously or by other methods if their illness becomes hopeless. A survey of California doctors showed that 20 to 30 percent were following instructions of such wills. Meanwhile, the hospicemovement, which its emphasis on providing comfort --- not cure --- to the dying patient, has gained momentum in many areas.11. Despite progress in society’s understanding of death and dying, t heory issues remain. Example: A woman, 87, afflicted by the nervous-system disorder of Parkinson’s disease, has a massive stroke and is found unconscious by her family. Their choices are to put her in a nursing home until she dies or to send her to a medical center for diagnosis and possible treatment. The family opts for a teaching hospital in New York city. Tests show the woman’s stroke resulted from a blood clot that is curable with surgery. After the operation, she says to her family: “Why did you bring me back to this agony?” Her health continues to worsen, and two years later she dies.12. On the other hand, doctors say prognosis is often uncertain and that patients, just because they are old and disabled, should not be denied life-saving therapy. Ethicists also fear that under the guise of medical decision not to treat certain patients, death may become too easy, pushing the country toward the acceptance of euthanasia.13. For some people, the agony of watching high-technology dying is too great. Earlier this year, Woodrow Wilson Collums, a retired dairyman from Poteet, Texas, was put on probation for the mercy killing of his older brother Jim, who lay hopeless in his bed at a nursing home, a victim of severe senility resul ting from Alzheimer’s disease. After the killing, the victim’s widow said: “I think God, Jim’s out of his misery. I hate to think it had to be done the way it was done, but I understand it. ”Crisis in Newborn Care14. At the other end of the life span, technology has so revolutionized newborn carethat it is no longer clear when human life is viable outside the womb. Newborn care has got huge progress, so it is absolutely clear that human being can survive independently outside the womb. Twenty-five years ago, infants weighting less than three and one-half pounds rarely survived. The current survival rate is 70 percent, and doctors are “salvaging” some babies that weigh only one and one-half pounds. Tremendous progress has been made in treating birth deformities such as spina bifida. Just ten years ago, only 5 percent of infants with transposition of the great arteries --- the congenital heart defect most commonly found in newborns --- survived. Today, 50 percent live.15. Yet, for many infants who owe their lives to new medical advances, survival has come at a price. A significant number emerge with permanent physical and mental handicaps.16. “The question of treatment and nontreatment of seriously ill newborns is not a single one,”says Thomas Murray of the Hastings Center. “But I feel strongly that retardation or the fact that someone is going to be less than perfect is not good grounds for allowing an infant to die.”17. For many parents, however, the experience of having a sick newborn becomes a lingering nightmare. Two years ago, an Atlanta mother gave birth to a baby suffering from Down’s Syndrome, a form of mental retardation; the child also had blocked intestines. The doctors rejected the parents’ plea not to operate, and today the child, severely retarded, still suffers intestinal problems.18. “Every time Melanie has a bowel movement, she cries,” explains her mother.“She’s not able to take care of herself, and we won’t live forever. I wanted to save her from sorrow, pain, and suffering. I don’t understand the emphasis on life at all costs, and I’m very angry at the doctors and the hospital. Who will take care of Melanie after we’re gone? Where will you doctors be then?”Changing Standards19. The choices posed by modern technology have profoundly changed the practice of medicine. Until now, most doctors have been activists, trained to use all the tools in their medical arsenals to treat disease. The current trend is toward nontreatment as doctors grapple with questions not just of who should get care but when to take therapy away.20. Always in the background is the threat of legal action. In August, two California doctors were charged with murdering a comatose patient by allegedly disconnecting the respirator and cutting off food and water. In 1981, a Massachusetts nurse was charged with murdering a cancer patient with massive doses of morphine but was subsequently acquitted.21. Between lawsuits, government regulations, and patients’ rights, many doctors feel they are under siege. Modern technology actually has limited their ability to make choices. More recently, these actions are resolved by committees.Public Policy22. In recent years, the debate on medical ethics has moved to the level of national policy. “It’s just beginning to hit us that we don’t have unlimited resources,” says Washington Hospital Center’s Dr. Lynch. “You can’t talk about ethics without talkingethics without talking about money.”23. Since 1972. Americans have enjoyed unlimited access to a taxpayer-supported, kidney dialysis program that offers life-prolonging therapy to all patients with kidney failure. To a number of police analysts, the program has grown out of control --- to a $1.4billion operation supporting 61,000 patients. The majority are over 50, and about a quarter have other illness, such as cancer or heart disease, conditions that could exclude them from dialysis in other countries.24. Some hospitals are pulling back from certain lifesaving treatment. Massachusetts General Hospital, for example, has decided not perform heart transplants on the ground that the high costs of providing such surgery help too few patients. Burn units --- through extremely effective --- also provide very expensive therapy for very few patients.25. As medical scientists push back the frontiers of therapy, the moral dilemma will continue to grow for doctors and patients alike, making the choice of to treat the basic question in modern medicine.1. 在特效药、风险性手术进程、放疗法以及特护病房方面的医学进展已为数千人带来新生。

研究生科技英语阅读课文翻译(1-10).

Unit 1 Genetically modified foods -- Feed the World?If you want to spark a heated debate at a dinner party, bring up the topic of genetically modified foods. For many people, the concept of genetically altered, high-tech crop production raises all kinds of environmental, health, safety and ethical questions. Particularly in countries with long agrarian traditions -- and vocal green lobbies -- the idea seems against nature.如果你想在某次晚宴上挑起一场激烈的争论，那就提出转基因食品的话题吧。

对许多人来说，高科技的转基因作物生产的概念会带来诸如环境、健康、安全和伦理等方面的各种问题。

特别是在有悠久的农业生产传统和主张环保的游说集团的国家里，转基因食品的主意似乎有悖自然。

In fact, genetically modified foods are already very much a part of our lives. A third of the corn and more than half the soybeans and cotton grown in the US last year were the product of biotechnology, according to the Department of Agriculture. More than 65 million acres of genetically modified crops will be planted in the US this year. The genetic is out of the bottle.事实上，转基因食品已经成为我们生活重要的一部分。

新思维大学英语2textB翻译

一些乐观的专家现在说，虽然这将是一个动荡的一年，全球市场，最糟糕的金融危机已经过去。

难道是如此。

我们相信，2009年将是更严厉的比许多预测。

我们进入新的一年，大萧条以来最严重的全球经济和金融危机的拼杀。

美国经济充其量，半途经济衰退始于2007年12月，将被证明最长和最严重的战后时期。

接近3万亿美元的信贷损失将离开美国银行和金融体系破产。

和信贷紧缩将持续为家庭，金融机构和企业的高负债率和偿付能力问题进行尖锐的去杠杆化过程。

更糟的是，世界上所有的发达经济体都陷入衰退。

许多新兴市场，包括中国，面临硬着陆的威胁。

有些人担心，这些条件会产生危险的尖峰通胀，但更大的风险是一种全球性的“滞缩”的：经济停滞，衰退和价格下滑的有毒组合。

我们很可能会看到脆弱的欧洲市场（匈牙利，罗马尼亚和保加利亚），关键拉丁美洲市场（阿根廷，委内瑞拉，厄瓜多尔和墨西哥），亚洲国家（巴基斯坦，印尼和韩国），以及俄罗斯，乌克兰和国家的面临严峻的财政压力波罗的海国家。

政策补救措施的作用很有限的破产问题制约货币刺激措施的成效，以及利率上升（下发出一波公共债务的）的风险侵蚀了财政刺激方案的增长效应。

只有在资不抵债的银行被关闭，其他人清理，资不抵债和家庭的债务水平降低会条件缓和。

从现在起，我们可以预期进一步下行风险，股市等风险资产，考虑到可能性，市场将继续受逊于预期的财经新闻被颠簸。

美国双胞胎财政和经常账户赤字将上升，在未来两年该国运行万亿美元以上的财政赤字。

我们都知道，外籍演员已拨付最这笔债务在过去数年。

20世纪80年代，美国也面临着双赤字的负担，而是依赖于从关键的战略合作伙伴，如日本和德国资助。

这一次，情况更令人担忧，因为今天的资金不是来自美国的盟国，但是从战略对手俄罗斯，中国和一些相对不稳定的产油国。

这让美国危险地依赖陌生人的仁慈。

这里也有一些好消息在这个相互依存关系。

这种关系意味着相互确保摧毁的经济确保了中国不能简单地拔出插头上的所有本次融资无痛苦相当数量的自找痛苦。

Elsevier Science Publishers B.V. (North-Holland), 1996 Chapter

Using Natural Language InterfacesHandbook of Human-Computer Interaction M. Helander (ed.)© Elsevier Science Publishers B.V . (North-Holland), 1996ChapterWilliam C. Ogden Philip BernickComputing Research Laboratory New Mexico State University Las Cruces, New Mexico 88003ogden | pbernick@ 1.0Introduction....................................1Habitability......................................22.0Evaluation Issues ...........................43.0Evaluations of Prototype andCommercial Systems......................6Laboratory Evaluations....................6Field Studies ..................................10Natural Language V ersus OtherInterface Designs...........................144.0Design Issues ................................18What is Natural?............................18Restrictions on V ocabulary............21Restrictions on Syntax...................22Functional Restrictions..................23Effects of Feedback .......................24Empirically Derived Grammars.....255.0Design Recommendations...........276.0Conclusion ...................................297.0Acknowledgments .......................308.0References (30)1.0IntroductionA goal of human factors research with com-puter systems is to develop human-computer communication modes that are both error tol-erant and easily learned. Since people already have extensive communication skills throughtheir own native or natural language (e.g.English, French, Japanese, etc.) many believe that natural language interfaces (NLIs) can provide the most useful and efﬁcient way for people to interact with computers.Although some authors express a belief that computers will never be able to under-stand natural language (e.g. Winograd &Flores, 1986), others feel that natural language processing technology needs only to advance sufﬁciently to make general purpose NLIs pos-sible. Indeed, there have been several attempts to produce commercial systems.The goal for most natural language sys-tems is to provide an interface that minimizes the training required for users. T o most, this means a system that uses the words and syntax of a natural language such as English. There is,however, some disagreement as to the amount of “understanding” or ﬂexibility required in the system.Systems have been proposed that permit users to construct English sentences by select-ing words from menus (Tennant et al. 1983).However, Woods (1977) rejects the idea that a system using English words in an artiﬁcial for-mat should be considered a natural language system, and assumes that the system should have an awareness of discourse rules that make it possible to omit easily inferred details. In further contrast, Perlman (1984) suggests that “naturalness” be determined by the context of the current application and urges the design of restricted “natural artiﬁcial” languages.Philosophical issues about the plausibility of computers understanding and generating natural language aside, it was widely believedthat the number of NLI applications would continue to grow (Waltz, 1983). Since then, work in graphical user interfaces (GUIs) has solved many of the problems that NLIs were expected to solve. As a result, NLIs have not grown at the rate ﬁrst anticipated, and those that have been produced are designed to use constrained language in limited domains.Research into NLIs continues, and a fre-quently asked question is how effective are these interfaces for human-computer commu-nication. The focus of this chapter is not to address the philosophical issues of natural lan-guage processing. Rather, it is to review empir-ical methods that have been applied to the evaluation of these limited NLIs and to review the results of user studies. We have not included the evaluation of speech systems, pri-marily due to space limitations. Readers inter-ested in speech system evaluations should consult Hirschman et al. (1992), and Goodine et al. (1992).This discussion of empirical results is also not limited to a single deﬁnition of natural lan-guage. Instead, it uses the most liberal deﬁni-tion of natural language and looks at systems that seek to provide ﬂexible input languages that minimize training requirements. The dis-cussion is limited to two study categories that report empirical results obtained from observ-ing users interacting with these systems. The ﬁrst category consists of prototype system studies developed in research environments. These studies have been conducted both in lab-oratory settings and in ﬁeld settings. The sec-ond category consists of simulated systems studied in the laboratory that are designed to help identify desirable attributes of natural lan-guage systems. Before reviewing these studies, some criteria for evaluating NLIs are pre-sented.HabitabilityHabitability is a term coined by Watt (1968) to indicate how easily, naturally, and effectively users can use language to express themselves within the constraints of a system language. A language is considered habitable if users can express everything that is needed for a task using language they would expect the system to understand. For example, if there are 26 ways that a user population would be likely to use to describe an operation, a habitable sys-tem will process all 26.In this review of studies, at least four domains in which a language can be habitable should be considered: conceptual, functional, syntactic, and lexical. Users of a NLI must learn to stay within the limits of all four domains.Conceptual: The conceptual domain of a lan-guage describes the language’s total area of coverage, and deﬁnes the complete set of objects and the actions covered by the inter-face. Users may only reference those objects and actions processable by the system. For example, a user should not ask about staff members who are managers if the computer system has no information about managers. Such a system would not understand the sen-tence:1.What is the salary of John Smith’s man-ager?Users are limited to only those concepts the system has information about. There is a difference between the conceptual domain of a language and the conceptual domain of the underlying system. The conceptual domain of a language can be expanded by recognizing concepts (e.g. manager) that exceed the sys-tem’s coverage and responding appropriately (Codd, 1974), (e.g. “There is no information on managers.”) The query could then be said to be part of the language’s conceptual domain, but not supported by the system’s. However,there will always be a limit to the number of concepts expressible within the language, and users must learn to refer to only these con-cepts.Functional: Functional domain is deﬁned by constraints about what can be expressed within the language without elaboration, and determines the processing details that users may leave out of their expressions. While con-ceptual coverage determines what can be expressed, functional coverage determines how it can be expressed. Natural language allows speakers to reference concepts many ways depending on listener knowledge and context. The functional domain is determined by the number of built-in functions or knowl-edge the system has available. For example, although a database may have salary informa-tion about managers and staff, a natural lan-guage interface still may not understand the question expressed in Sentence 1 if the proce-dure for getting the answer is too complicated to be expressed in one question. For example, the answer to Sentence 1 may require two steps; one to retrieve the name of the manager and another to retrieve the salary associated with the name. Thus, the system may allow the user to get the answer with two questions:2aWho is the manager of John Smith? System: MARY JONES2bWhat is the salary of Mary Jones?With these questions, the user essentially speciﬁes procedures that the system is capable of. The question in Sentence 1 does not exceed the conceptual domain of the language because salaries of managers are available. Instead, it expresses a function that does not exist (i.e. a function that combines two retrievals from one question). Nor is it a syntactic limitation since the system might understand a question with the same syntactic structure as Sentence 1, but that can be answered with a single database retrieval:3.What is the name of John Smith’s man-ager?Other, more formal, languages vary on functional coverage as well. Concepts like square root can be expressed directly in some languages but must be computed in others. A habitable system provides functions that users expect in the interface language. Since there will be a limit on the functional domain of the language, users must learn to refer to only those functions contained in the language. Syntactic: The syntactic domain of a language refers to the number of paraphrases of a single command that the system understands. A sys-tem that did not allow possessives might not understand Sentence 1, but would understand Sentence 4:4.What is the salary of the manager ofJohn Smith?A habitable system must provide the syn-tactic coverage users expect.Lexical: The lexical domain of a language refers to words contained in the system’s lexi-con. Sentence 1 might not be understood if the language does not accept the word “salary” but accepts “earnings.” Thus, Sentence 5 would be understood:5.What are the earnings of the manager ofJohn Smith?A natural language system must be made habitable in all four domains because it will be difﬁcult for users to learn which domain is vio-lated when the system rejects an expression. A user entering a command like Sentence 1 that is rejected by the system, but does not violate the conceptual domain, might be successful with any of the paraphrases in Sentence 2, 4, or 5. Determining which one will depend upon the functional, syntactic, or lexical coverage of the language. When evaluating the results of user studies, it is important to keep the distinc-tions between habitable domains in mind.NLIs attempt to cover each domain by meeting the expectations of the user, and inter-face habitability is determined by how well these expectations are met. Of course, the most habitable NLI would be one capable of passing a Turing Test or winning the Loebner Prize1.It can be difﬁcult to measure the habitabil-ity of a language. To determine how much cov-erage of each domain is adequate for a given task requires good evaluation methods. The next section reviews some of the methodologi-cal issues to consider when evaluating natural language interfaces.2.0Evaluation IssuesWhen evaluating the studies presented in this chapter there are several methodological issues that need to be considered: user selection and training, task selection and presentation, so-called Wizard-of-Oz simulations (Kelley, 1984), parsing success rates, and interface cus-tomization. Here we present a brief discussion of these issues.User selection and training: Evaluating any user-system interface requires test participants who represent the intended user population. For natural language evaluations, this is a par-ticularly important factor. A language’s habit-ability depends on how well it matches user knowledge about the domain of discourse. Therefore, test participants should have knowl-edge similar to that held by the actual users in the target domain. Some studies select care-fully, but most have tried to train participants in the domain to be tested. It is likely, however, 1.In the 1950’s Turing proposed a test designed to challengeour beliefs about what it means to think (Turing, 1950).The Loebner variant involves computer programs with NLIs that have been designed to converse with users (Epstein, 1993). Users do not know whether they are com-municating with a computer or another user. Winning the prize involves fooling the users into thinking they are con-versing with another human, when, in fact, they are com-municating with a computer.that participants employed for an experiment will be less motivated to use the NLI produc-tively than existing users of the database. On the other hand, a measure of control is pro-vided when participants are trained to have a common understanding of the domain.Training ranges from a minimal introduc-tion to the domain to extensive training on the interface language that can include instructions and practice on how to avoid common traps. Obviously, the quality of training given to users signiﬁcantly affects user performance. Therefore, the kind and amount of training users receive should represent the training that users are expected to have with the actual product.Task generation and presentation: The goal of studies designed to evaluate the use of natu-ral language is to collect unbiased user expres-sions as they are engaged in computer-related tasks. These tasks should be representative of the type of work the user would be expected to accomplish with the interface and be presented in a way that would not inﬂuence the form of expression. In most studies, tasks are gener-ated by the experimenter who attempts to cover the range of function available in the interface. Letting users generate their own tasks is an alternative method, but results in a reduction of experimenter control. This method also requires that users be motivated to ask appropriate questions.Experimenter-generated tasks are neces-sary if actual users are not available or need prior training. These tasks can simulate a hypothesized level of user knowledge and experience by presenting tasks assumed to be representative of questions that would be asked of the real system. The disadvantage of experi-menter-generated tasks are that they do not allow for assessment of the language’s concep-tual habitability because experimenters usually generate only solvable tasks.User-generated tasks have the advantage of being able to assess the language’s conceptual and functional coverage because users are free to express problems that may be beyond the capabilities of the system. The disadvantage of user-generated tasks is that a study’s results may not generalize beyond the set of questions asked by the selected set of users; no attempt at covering all of the capabilities of the interface will have been made. Another disadvantage is that actual users of the proposed system must be available.How experimenter-generated or user-gen-erated tasks are presented to test participants has strong inﬂuence on the expressions test participants generate. In an extreme case, par-ticipants would be able to solve the task merely by entering the task instructions as they were presented. At the other extreme, task instructions would encourage participants to generate invalid expressions.Researchers usually choose one of two methods for overcoming these extremes. One method presents the task as a large generally-stated problem that requires several steps to solve. This method not only tests the habitabil-ity of the language, but also the problem-solv-ing ability of the participants. Participants are free to use whatever strategy seems natural and to use whatever functions they expect the inter-face to have. Like user-generated tasks, this method does not allow researcher to test all of the anticipated uses of the system because par-ticipants may not ask sufﬁciently complicated questions.An alternative method has been used to test more of a system’s functions. In this method, participants are given items like tables or graphs, with some information missing, and are then asked to complete these items by ask-ing the system for this missing information. This method gives an experimenter the most control over the complexity of expressions that participants would be expected to enter. How-ever, some expressions may be difﬁcult to rep-resent non-linguistically, so coverage may not be as complete as desired (c.f. Zoeppritz, 1986). An independent measure of how partic-ipants interpreted the questions should also be used to determine whether participants under-stood the task. For example, participants may be asked to do the requested task manually before asking the computer to do it.Wizard-of-Oz (WOz) simulations: WOz stud-ies simulate a natural language system by using a human to interpret participants’ com-mands. In a typical experiment a participant will type a natural language command on one terminal that will appear on a terminal moni-tored by an operator (the Wizard) hidden in another location. The Wizard interprets the command and takes appropriate actions that result in messages that appear on the partici-pant’s terminal. Usually the Wizard makes decisions about what a real system would or would not understand. It is likely that the Wiz-ard will not be as consistent in responding as the computer would, and this problem should be taken into account when reviewing these studies. However, WOz simulations are useful for quickly evaluating potential designs. Evaluation of parsing success rates: An often reported measure of habitability is the propor-tion of expressions that can be successfully parsed by the language processor returning a result. But studies that report parsing success rates as a global indicator of how well the sys-tem is doing assume that all commands are equally complex when they are not (Tennant, 1980).A high success rate may be due to partici-pants in the study repeating a simple request many times. For example, Tennant observed a participant asking “How many NOR hours did plane 4 have in Jan of 1973,” and then repeat-ing this request again for each of the 12 months. This yields 12 correctly parsed ques-tions. On the other hand, another participanttrying to get the information from all 12 months in one request had two incorrectly parsed requests before correctly requesting “List the NOR hours in each month of 1973 for plane 4.” The second participant had a lower parse rate percentage, but obtained the desired information with less work than the ﬁrst partic-ipant. In fact, Tennant found that successful task solution scores did not correlate with pars-ing success rates. Therefore, a user’s ability to enter allowable commands does not guarantee that they can accomplish their tasks.Parsing success rates need to be interpreted in light of other measures such as number of requests per task, task solution success, and solution time. Since these measures depend on the tasks users are given, which vary from study to study, it would be inappropriate to compare systems across studies.Interface customization: Finally, how a sys-tem is customized for the application being evaluated is an important methodological issue. Each NLI requires that semantic and pragmatic information about the task domain be encoded and entered. Evaluation results are signiﬁcantly affected if researchers capture and enter this information poorly. Since most evaluations have been conducted on systems that were customized by system developers, these systems represent ideally adapted inter-faces. However, most operational systems will not have the advantage of being customized by an expert, so performance with the operational system may be worse.3.0Evaluations of Prototype andCommercial SystemsThe feasibility of the natural language approach is usually shown by building and demonstrating a prototype system prior to delivering it to the marketplace. Very few of these prototype systems have been evaluated by actually measuring user performance. The few that have been evaluated are reviewed here, beginning with a review of evaluations done under controlled laboratory conditions, and followed by a review of ﬁeld studies.Laboratory Evaluations LADDER: Hershman et al. (1979) studied ten Navy ofﬁcers using LADDER, a natural lan-guage query system designed to provide easy access to a naval database. The goal of this study was to simulate as closely as possible the actual operational environment in which LAD-DER would be implemented. To accomplish this, Navy ofﬁcers were trained to be interme-diaries between a hypothetical decision maker and the computer’s database in a simulated search and rescue operation. Ofﬁcers were given global requests for information and were asked to use LADDER to obtain the necessary information. Training consisted of a 30 minute tutorial session that included a lengthy discus-sion of LADDER’s syntax and vocabulary, fol-lowed by one hour of practice that involved typing in canned queries and solving some simple problems. Compared to participants in other studies, these participants were moder-ately well trained.Participants were largely successful at obtaining necessary information from the data-base, and were able to avoid requests for infor-mation not relevant to their task. Thus, it seems that participants were easily able to stay within the conceptual domain of the language. Hersh-man et al, however, report that LADDER parsed only 70.5 percent of the 366 queries submitted. Participants also used twice the number of queries that would have been required by an expert LADDER user. Almost 80 percent of the rejected queries were due to syntax errors. Apparently, LADDER’s syntac-tic coverage was too limited for these moder-ately trained users. However, a contributing factor may have been the wording of informa-tion requests given to the participants. These requests were designed not to be understoodby LADDER and this could have inﬂuenced the questions typed by the participants.Hershman et al. concluded that the system could beneﬁt from expanded syntactic and lex-ical coverage, but that users would still require training. Apparently, the training that was given to participants in this study was adequate for teaching the system’s functional and con-ceptual coverage, but not for teaching its syn-tactic and lexical coverage.PLANES: Tennant (1979) conducted several studies of prototype systems and came to simi-lar conclusions. However, Tennant also pro-vides evidence that users have trouble staying within the conceptual limits of a natural lan-guage query interface. Tennant studied users of two natural language question answering sys-tems: PLANES and the Automatic Advisor. PLANES was used with a relational database of ﬂight and maintenance records for naval air-craft, and the Automatic Advisor was used to provide information about engineering courses offered at a university. Participants were uni-versity students who were unfamiliar with the database domains of the two systems. Partici-pants using PLANES were given a 600-word script that described the information contained in the database. Participants using the Auto-matic Advisor were only given a few sentences describing the domain. Participants received no other training. Problems were presented either in the form of partially completed tables and charts or in the form of long descriptions or high-level problems that users had to decompose.Problems were generated either by people familiar with the databases or by people who had received only the brief introduction given to the participants. The purpose of having problems generated by people who had no experience with the system was to test the con-ceptual completeness of the natural language systems. If all of the problems generated by inexperienced users could be solved, then the system could be considered conceptually com-plete. However, this was not the case. Tennant does not report statistics, but claims that some of the problems generated by the inexperi-enced users could not have been solved using the natural language system, and consequently participants were less able to solve these prob-lems than the problems generated by people familiar with the database.Tennant concluded that the systems were not conceptually or functionally complete and that without extending the conceptual coverage beyond the limits of the database contents, nat-ural language systems would be as difﬁcult to use as formal language systems.NLC: Other laboratory evaluations of proto-type systems have been conducted using a nat-ural language programming system called NLC (Biermann et al., 1983). The NLC system allows users to display and manipulate numeri-cal tables or matrices. Users are limited to commands that begin with an imperative verb and can only refer to items shown on their dis-play terminals. Thus, the user is directly aware of some of the language’s syntactic and con-ceptual limitations.A study conducted by Biermann et al. (1983) compared NLC to a formal program-ming language, PL/C. Participants were asked to solve a linear algebra problem and a “grade-book” problem using either NLC or PL/C. Par-ticipants using NLC were given a written tuto-rial, a practice session, the problems, and some brief instructions on using an interactive termi-nal. Participants using PL/C were given the problems and used a batch card reading sys-tem. The 23 participants were just completing a course in PL/C and were considered to be in the top one-third of the class. Each participant solved one of the problems using NLC and the other using PL/C. Problems were equally divided among languages.Results show that 10 of 12 (83 percent) participants using NLC correctly completedthe linear algebra problem in an average of 34 minutes. This performance compared favor-ably to that of the PL/C group in which 5 of 11 (45 percent) participants correctly completed this problem in an average 165 minutes. For the “grade-book” problem, 8 of 11 (73 per-cent) NLC participants completed the problem correctly in an average of 68 minutes while 9 of 12 (75 percent) PL/C participants correctly completed the problem in an average of 125 minutes The reliability of these differences was not tested statistically, but it was clear that participants with 50 minutes of self-paced training could use a natural language program-ming tool on problems generated by the sys-tem designers. These participants also did at least as well as similar participants who used a formal language which they had just learned.The system was able to process 81 percent of the natural language commands correctly. Most of the incorrect commands were judged to be the result of “user sloppiness” and non-implemented functions. Users stayed within the conceptual domain when they were given an explicit model of the domain (as items on the display terminal) and were given problems generated by the system designers. However, users seemed to have difﬁculty staying within the functional limitation of the system and were not always perfect in their syntactic and lexical performance.The idea of referring to an explicit concep-tual model that can be displayed on the screen is a good one. Biermann et al. also pointed out the necessity of providing immediate feedback via an on-line display to show users how their commands were interpreted. If there was a misinterpretation, it would be very obvious, and the command could be corrected with an UNDO instruction.In another study of NLC, Fink et al. (1985), examined the training issue. Eighteen participants with little or no computer experi-ence were given problems to solve with NLC.To solve these problems, participants had to formulate conditional statements that the sys-tem was capable of understanding. Participants received no training, nor were they given examples of how to express these conditions. In other respects the experimental methodol-ogy was the same as Biermann et al. (1983). The following is an example of an allowable conditional statement in NLC.For i = 1 to 4, double row i if it containsa positive entry.Fink et al. reported large individual differ-ences in the participants’ abilities to discover rules for generating conditional statements. One participant made only one error in solving 13 problems, whereas another participant could not solve any problems. In general, par-ticipants made large numbers of errors solving the ﬁrst few problems and made few errors after discovering a method that worked. These ﬁndings support the conclusion that training is required for these kinds of natural language systems.A commercial system: Customization can make it difﬁcult to study prototype natural lan-guage interfaces. The ﬂexibility of commercial systems demands customization, but a sys-tem’s usability depends on its natural language processor and on how well the interface has been customized for the application. When usability problems occur, evaluators may have trouble determining whether the natural lan-guage processor or the customization is responsible.Ogden & Sorknes (1987) evaluated a PC-based natural language query product that allowed users to do their own customizing. The evaluation goal was to assess how well a commercially available NLI would meet the needs of a database user who was responsible for customization, but who had no formal query training. The interface was evaluated by observing seven participants as they learned and used the product. They were given the。

Structural Geology

More informationStructural GeologyLavishly illustrated in color,this textbook takes an applied approach to introduceundergraduate students to the basic principles of structural geology.The bookprovides unique links to industry applications in the upper crust,including petroleumand groundwater geology,which highlight the importance of structural geology inexploration and exploitation of petroleum and water resources.Topics range fromfaults and fractures forming near the surface to shear zones and folds of the deepcrust.Students are engaged through examples and parallels drawn from practicaleveryday situations,enabling them to connect theory with practice.Containingnumerous end-of-chapter problems,e-learning modules,and with stunningﬁeldphotos and illustrations,this book provides the ultimate learning experience forall students of structural geology.Haakon Fossen is Professor of Structural Geology at the University of Bergen,Norway,where he is afﬁliated with the Department of Earth Science,the NaturalHistory Collections,and the Centre for Integrated Petroleum Research(CIPR).His professional career has also involved work as an exploration and productiongeologist/geophysicist for Statoil and periods of geologic mapping and mineralexploration in Norway.His research ranges from hard to soft rocks and includesstudies of folds,shear zones,formation and collapse of the Caledonian Orogen,numerical modeling of deformation(transpression),the evolution of the NorthSea rift,and studies of deformed sandstones in the western United States.He hasconducted extensiveﬁeld work in various parts of the world,notably Norway,Utah/Colorado and Sinai,and his research is based onﬁeld mapping,microscopy,physical and numerical modeling,geochronology and seismic interpretation.Professor Fossen has been involved in editing several international geology journals,has authored over90scientiﬁc publications,and has written two books and severalbook chapters.He has taught undergraduate structural geology courses for overten years and has a keen interest in developing electronic teaching resources to aidstudent visualization and understanding of geologic structures.More informationMore informationMore informationcambridge university pressCambridge,New York,Melbourne,Madrid,Cape Town,Singapore,Sa˜o Paulo,Delhi,Dubai,TokyoCambridge University PressThe Edinburgh Building,Cambridge CB28RU,UKPublished in the United States of America by Cambridge University Press,New YorkInformation on this title:/9780521516648#Haakon Fossen2010This publication is in copyright.Subject to statutory exceptionand to the provisions of relevant collective licensing agreements,no reproduction of any part may take place withoutthe written permission of Cambridge University Press.First published2010Printed in the United Kingdom at the University Press,CambridgeA catalogue record for this publication is available from the British LibraryLibrary of Congress Cataloging-in-Publication DataFossen,Haakon,1961–Structural geology/Haakon Fossen.p.cm.ISBN978-0-521-51664-8(Hardback)1.Geology,Structural.I.Title.QE601.F6872010551.8–dc222010011781ISBN978-0-521-51664-8HardbackAdditional resources for this publication at /9780521516648Cambridge University Press has no responsibility for the persistence oraccuracy of URLs for external or third-party internet websites referred toin this publication,and does not guarantee that any content on suchwebsites is,or will remain,accurate or appropriate.ContentsHow to use this book page viiiPrefacexi Acknowledgments xii List of symbolsxiii1...........Structural geology and structural analysis11.1Approaching structural geology 21.2Structural geology and tectonics 21.3Structural data sets 41.4Field data51.5Remote sensing and geodesy 51.6DEM,GIS and Google Earth 61.7Seismic data81.8Experimental data 101.9Numerical modeling 121.10Other data sources 121.11Organizing the data 121.12Structural analysis 151.13Concluding remarks182...........Deformation212.1What is deformation?222.2Components of deformation 232.3System of reference242.4Deformation:detached from history 252.5Homogeneous and heterogeneous deformation252.6Mathematical description of deformation 262.7One-dimensional strain 282.8Strain in two dimensions 282.9Three-dimensional strain 302.10The strain ellipsoid302.11More about the strain ellipsoid 312.12Volume change322.13Uniaxial strain (compaction)332.14Pure shear and coaxial deformations 352.15Simple shear 352.16Subsimple shear362.17Progressive deformation and flow parameters 362.18Velocity field 382.19Flow apophyses 392.20Vorticity and W k402.21Steady-state deformation412.22Incremental deformation422.23Strain compatibility and boundaryconditions422.24Deformation history from deformed rocks 432.25Coaxiality and progressive simple shear 442.26Progressive pure shear462.27Progressive subsimple shear472.28Simple and pure shear and their scaledependence482.29General three-dimensional deformation 492.30Stress versus strain50Summary523...........Strain in rocks553.1Why perform strain analysis?563.2Strain in one dimension 563.3Strain in two dimensions 563.4Strain in three dimensions 61Summary654...........Stress694.1Definitions,magnitudes and units 704.2Stress on a surface 704.3Stress at a point 714.4Stress components724.5The stress tensor (matrix)734.6Deviatoric stress and mean stress 744.7Mohr circle and diagram 75Summary765...........Stress in the lithosphere795.1Importance of stress measurements 805.2Stress measurements 805.3Reference states of stress835.4The thermal effect on horizontal stress 865.5Residual stress 885.6Tectonic stress885.7Global stress patterns905.8Differential stress,deviatoric stress and some implications 93Summary94More information6...........Rheology976.1Rheology and continuum mechanics986.2Idealized conditions996.3Elastic materials996.4Plasticity and flow:permanentdeformation1036.5Combined models1076.6Experiments1096.7The role of temperature,water etc.1106.8Definition of plastic,ductile and brittledeformation1126.9Rheology of the lithosphere113Summary115 7...........Fracture and brittle deformation1197.1Brittle deformation mechanisms1207.2Types of fractures1217.3Failure and fracture criteria1267.4Microdefects and failure1307.5Fracture termination and interaction1367.6Reactivation and frictional sliding1387.7Fluid pressure,effective stressand poroelasticity1397.8Deformation bands and fracturesin porous rocks141Summary148 8...........Faults1518.1Fault terminology1528.2Fault anatomy1568.3Displacement distribution1608.4Identifying faults in an oil field setting1618.5The birth and growth of faults1658.6Growth of fault populations1748.7Faults,communication and sealingproperties181Summary185 9...........Kinematics and paleostressin the brittle regime1899.1Kinematic criteria1909.2Stress from faults1929.3A kinematic approach to fault slip data1969.4Contractional and extensional structures197Summary20010...........Deformation at the microscale20310.1Deformation mechanisms andmicrostructures20410.2Brittle versus plastic deformationmechanisms20410.3Brittle deformation mechanisms20510.4Mechanical twinning20510.5Crystal defects20710.6From the atomic scale to microstructures213Summary216 11...........Folds and folding21911.1Geometric description22011.2Folding:mechanisms and processes22611.3Fold interference patterns and refolded folds23511.4Folds in shear zones23711.5Folding at shallow crustal depths238Summary239 12...........Foliation and cleavage24312.1Basic concepts24412.2Relative age terminology24512.3Cleavage development24612.4Cleavage,folds and strain25012.5Foliations in quartzites,gneissesand mylonite zones254Summary256 13...........Lineations25913.1Basic terminology26013.2Lineations related to plastic deformation26013.3Lineations in the brittle regime26313.4Lineations and kinematics265Summary268 14...........Boudinage27114.1Boudinage and pinch-and-swell structures27214.2Geometry,viscosity and strain27214.3Asymmetric boudinage and rotation27514.4Foliation boudinage27714.5Boudinage and the strain ellipse27814.6Large-scale boudinage279Summary281ContentsviMore information15...........Shear zones and mylonites28515.1What is a shear zone?28615.2The ideal plastic shear zone28915.3Adding pure shear to a simple shear zone29415.4Non-plane strain shear zones29615.5Mylonites and kinematic indicators29715.6Growth of shear zones306Summary307 16...........Contractional regimes31116.1Contractional faults31216.2Thrust faults31316.3Ramps,thrusts and folds31916.4Orogenic wedges323Summary329 17...........Extensional regimes33317.1Extensional faults33417.2Fault systems33517.3Low-angle faults and core complexes33817.4Ramp-flat-ramp geometries34117.5Footwall versus hanging-wall collapse34217.6Rifting34217.7Half-grabens and accommodation zones34317.8Pure and simple shear models34417.9Stretching estimates,fractalsand power law relations34517.10Passive margins and oceanic rifts34717.11Orogenic extension and orogenic collapse34817.12Postorogenic extension350Summary351 18...........Strike-slip,transpressionand transtension35518.1Strike-slip faults35618.2Transfer faults35618.3Transcurrent faults35818.4Development and anatomyof strike-slip faults35918.5Transpression and transtension36318.6Strain partitioning366Summary36819...........Salt tectonics37119.1Salt tectonics and halokinesis37219.2Salt properties and rheology37319.3Salt diapirism,salt geometryand the flow of salt37419.4Rising diapirs:processes38319.5Salt diapirism in the extensional regime38319.6Diapirism in the contractional regime38619.7Diapirism in strike-slip settings38919.8Salt collapse by karstification38919.9Salt de´collements390Summary39220...........Balancing and restoration39520.1Basic concepts and definitions39620.2Restoration of geologic sections39620.3Restoration in map view40320.4Restoration in three dimensions40420.5Backstripping404Summary40621...........A glimpse of a larger picture40921.1Synthesizing41021.2Deformation phases41021.3Progressive deformation41121.4Metamorphic textures41121.5Radiometric dating and P–T–t paths41421.6Tectonics and sedimentation415Summary417Appendix A:More about the deformation matrix418 Appendix B:Stereographic projection422 Glossary428 References451Cover and chapter image captions455Index457Contents viiMore information.............................................................................................................................................................HOWTO USE THIS BOOK Each chapter starts with a general introduction ,which presents a context for the topic within structural geology as a whole.These introductions provide a roadmap for the chapter and will help you to navigate through the book.The main text contains highlighted terms and key expressions that you will need to understand and become familiar with.Many of these terms are listed in the Glossary at the back of the book.The Glossary allows you to easily look up terms whenever needed and can also be used to review important topics and key facts.Each chapter also contains a series of highlighted statements to encourage you to pause and review your understanding of what you have read.Most chapters have one or more boxes containing in-depth information about a particular subject,helpful examples or relevant background information.Other important points are brought together in the chapter summaries.Review questions should be used to test your understanding of the chapter before moving on to the next topic.Answers to these questions are given on the book‘s web-page.More information.............................................................................................................................................................Further reading sections provide references toselected papers and books for those interested inmore detailed or advanced information.In addition,there are links to web-based e-learning modules atthe end of the ing these modules ishighly recommended after reading the chapter aspart of review and exam preparation.The modulesprovide supplementary information thatcomplements the main text.Web-based resourcesSpecially prepared resources,unique to this book,are available from the book‘s web-page:/fossen.These are:Flash based e-learning modules that combine animations,text,illustrations and photographs.These present key aspects of structuralgeology in a highly visual andinteractive environment.All of the figures for each chapter asjpeg files for use by instructors andreaders.Supplementary figures illustratingadditional geologic structures andfield examples.Answers to the review questionspresented at the end of each chapter.Additional exercises and solutions.A repository for further images,animations,videos,exercises andother resources provided by readersand instructors as a communityresource.More informationPrefaceThis textbook is written to introduce undergraduate students,and others with a general geologic background, to basic principles,aspects and methods of structural geology.It is mainly concerned with the structural geology of the crust,although the processes and struc-tures described are relevant also for deformation that occurs at deeper levels within our planet.Further,remote data from Mars and other planets indicate that many aspects of terrestrial structural geology are relevant also beyond our own planet.The field of structural geology is very broad,and the content of this book presents a selection of important subjects within this field.Making the selection has not been easy,knowing that lecturers tend to prefer their own favorite aspects of,and approaches to,structural geology,or make selections according to their local departmental course curriculum.Existing textbooks in structural geology tend to emphasize the ductile or plastic deformation that occurs in the middle and lower crust.In this book I have tried to treat the frictional regime in the upper crust more extensively so that it better balances that of the deeper parts of the crust, which makes some chapters particularly relevant to courses where petroleum geology and brittle deform-ation in general are emphasized.Obtaining this balance was one of several motivating factors for writing this book,and is perhaps related to my mixed petroleum geology and hard-rock structural geol-ogy experience.Other motivating factors include the desire to make a book where I could draw or redraw all of the illustrations and be able to present the first full-color book in structural geology.I also thought that a fundamental structural geology text of the twenty-first century should come with specially prepared e-learning resources,so the package of e-learning material that is presented with this book should be regarded as part of the present book concept.Book structureThe structure of the book is in many ways traditional, going from strain(Chapters2and3)to stress(Chapters4 and5)and via rheology(Chapter6)to brittle deformation (Chapters7and8).Of these,Chapter2contains material that would be too detailed and advanced for some students and classes,but selective reading is possible.Then,after a short introduction to the microscale structures and processes that distinguish crystal-plastic from brittle deformation(Chapter10),ductile deformation structures such as folding,boudinage,foliations and shear zones are discussed(Chapters11–15).Three consecutive chapters then follow that are founded on the three principal tectonic regimes(Chapters16–18)before salt tectonics and restoration principles are presented(Chapters19 and20).A final chapter,where links to metamorphic petrology as well as stratigraphy are drawn,rounds off the book,and suggests that structural geology and tectonics largely rely on other disciplines.The chapters do not have to be read in numerical order,and most chapters can be used individually.Emphasis and examplesThe book seeks to cover a wide ground within the field of structural geology,and examples presented in the text are from different parts of the world.However,pictures and illustrations from a few geographic areas reappear.One of those is the North Sea rift system,notably the Gullfaks oil field,which I know quite well from my years with the Norwegian oil company Statoil.Another is the Colorado Plateau(mostly Utah),which over the last two decades has become one of my favorite places to do field work.A third, and much wetter and greener one,is the Scandinavian Caledonides.From this ancient orogen I have chosen a number of examples to illustrate structures typical of the plastic regime.More informationAcknowledgmentsDuring the writing of this textbook I have built on experience and knowledge achieved through my entire career,from early days as a student,via various industrial and academic positions,to the time I have spent writing the manuscript.In this respect I want to thank fellow students,geologists and professors with whom I have interacted during my time at the Universities of Bergen, Oslo,Minnesota and Utah,at Utah State University, in Statoil and at the Geological Survey of Norway.In particular,my advisers and friends Tim Holst,Peter Hudleston and Christian Teyssier deserve thanks for sharing their knowledge during my three years in Minnesota,and among the many fellow PhD students there special thanks are due to Jim Dunlap,Eric Heather-ington,David Kirschner,Labao Lan and,particularly, Basil Tikoff for valuable discussions and exchange of ideas as we were exploring various aspects of structural geology. Among coworkers and colleagues I wish to extend special thanks to Roy Gabrielsen,who contributed to the Norwe-gian book on which this book builds,Jonny Hesthammer for good company in Statoil and intense field discussions, Egil Rundhovde for co-leading multiple field trips to the Colorado Plateau,and to Rich Schultz who is always keen on intricate discussions on fracture mechanics and deformation bands in Utah and elsewhere.Special thanks also go to Wallace Bothner,Rob Butler, Nestor Cardozo,Declan DePaor,Jim Evans,James Kirkpatrick,Stephen Lippard,Christophe Pascal,Atle Rotevatn,Zoe Shipton,Holger Stunitz and Bruce Trudgill for reading and commenting on earlier versions of the text.I am also thankful to colleagues and com-panies who assisted in finding appropriate figures and seismic examples of structures,each of which is acknow-ledged in connection with the appearance of the illustra-tion in the book,and to readers who will send their comments to me so that improvements can be made for the next edition.PrefacexiiMore informationMore informationa long axis of ellipse representing a microcrackA area;empirically determined constant in flow lawsc short axis of ellipse representing a microcrackC cohesion or cohesional strength of a rockC f cohesive strength of a faultd offsetd cl thickness of clay layerD displacement;fractal dimensionD max maximum displacement along a fault trace or on a fault surfaceD deformation(gradient)matrixe¼e elongation_e¼_e elongation rate(d e=d t)_e x and_e y elongation rates in the x and y directions(sÀ1)e1,e2and e3eigenvectors of deformation matrix,identical to the three axesof strain ellipsoid"e logarithmic(natural)elongation"e s natural octahedral unit shearE Young’s modulus;activation energy for migration of vacancies through a crystal(J molÀ1KÀ1)E*activation energyF force vector(kg m sÀ2,N)F n normal component of the force vectorF s shear component of the force vectorg acceleration due to gravity(m/s2)h layer thicknessh0initial layer thicknessh T layer thickness at onset of folding(buckling)ISA1–3instantaneous stretching axesK bulk modulusK i stress intensity factorK c fracture toughnessk parameter describing the shape of the strain ellipsoid(lines in the Flinn diagram)k x and k y pure shear components,diagonal elements in the pure shearand simple shear matricesl line length(m)l 0line length prior to deformation (m)L velocity tensor (matrix)L fault length;wavelengthL d dominant wavelengthL T actual length of a folded layer over the distance of one wavelength n exponent of displacement-length scaling law p f fluid pressure P pressure (Pa)Q activation energyR ellipticity or aspect ratio of ellipse (long over short axis);gas constant (J kg À1K À1)R f final ellipticity of an object that was non-circular prior to deformation R i initial ellipticity of an object (prior to deformation)R s same as R ,used in connection with the R f /f -method to distinguish it from R f R xy X /Y R yz Y /Zs stretching_S stretching tensor,symmetric part of L t time (s)Ttemperature (K or C);uniaxial tensile strength (bar);local displacement or throw of a fault when calculating SGR and SSF v velocity vector (m/s)V volume (m 3)V 0volume prior to deformation V p velocity of P-waves V s velocity of S-waves w vorticity vector w vorticityW vorticity (or spin)tensor,which is the skew-symmetric component of L W k kinematic vorticity numberx vector or point in a coordinate system prior to deformation x 0vector or point in a coordinate system after deformation x ,y ,z coordinate axes,z being vertical X ,Y ,Z principal strain axes;X !Y !Z Z crustal depth (m)athermal expansion factor (K À1);Biot poroelastic parameter;angle between passive marker and shear direction at onset of non-coaxial deformation (Chapter 15);angle between flow apophyses (Chapter 2)a 0angle between passive marker and shear direction after a non-coaxial deformationb stretching factor,equal to s D volume change factor Áchange in stressList of symbolsxiv More informationg shear strain"g oct octahedral shear strain _g shear strain rateG non-diagonal entry in deformation matrix for subsimple shear viscosity constant (N s m À2)lquadratic elongationl 1,l 2and l 3eigenvalues of deformation matrix √l 1,√l 2and √l 3length of strain ellipse axesm shear modulus;viscositym f coefficient of sliding frictionm L viscosity of buckling competent layerm M viscosity of matrix to buckling competent layer n Poisson’s ratio;Lode’s parameteryangle between the normal to a fracture and s 1;angle between ISA 1and the shear plane y 0angle between X and the shear plane r density (g/cm 3)s stress (D F /D A )(bar:1bar ¼1.0197kg/cm 2¼105Pa ¼106dyne/cm 2)sstress vector (traction vector)s 1>s 2>s 3principal stresses " effective stress s a axial stresss dev deviatoric stresss diff differential stress (s 1Às 3)s H max horizontal stress s h min horizontal stresss h *average horizontal stress in thinned part of the lithosphere (constant-horizontal-stress model)s m mean stress (s 1þs 2þs 3)/3s n normal stress s r remote stress s s shear stress s t tectonic stresss tip stress at tip of fracture or point of max curvature along pore margin s tot total stress (s m þs dev )s v vertical stressg n normal stress at grain–grain or grain–wall contact areas in porous medium w n average normal stress exerted on wall by grains in porous medium f internal friction (rock mechanics);angle between X and a reference line at onset of deformation (R f /f -method)f 0angle between X and a reference line after a deformation (R f /f -method)F porosityc angular shearvangular velocity vectorList of symbols xvMore informationMore information。

Cambridge IGCSE Biology目录中文翻译(配页码)

Cambridge IGCSE Biology（本教材适用于国内九、十年级左右学习难度）1.生物的特征与分类------------------------------------------------------ 1●生物的特征-------------------------------------------------------------- 1-植物界（分类）-动物界（分类）-真菌界-原生动物●分类系统的概念和应用----------------------------------------------------2-物种-二分类系统（双名法）●生物的特性--------------------------------------------------------------6 ●二分类的关键------------------------------------------------------------212.生物及其生命的维持----------------------------------------------------24●细胞和结构--------------------------------------------------------------24-动物细胞和植物细胞的结构●不同水平层次------------------------------------------------------------29-特殊的分化细胞-组织和器官-系统●标本尺寸----------------------------------------------------------------33-显微镜的构造和原理（生物相关尺度标尺图）3.物质进出细胞-----------------------------------------------------------36●扩散-------------------------------------------------------------------36-气体扩散和液体溶质扩散的重要性●渗透作用----------------------------------------------------------------40-动物细胞-植物细胞-实验：渗透装置-质壁分离●主动运输----------------------------------------------------------------48-主动运输的重要性4.生物分子----------------------------------------------------------------51●生物分子----------------------------------------------------------------51-糖类-脂肪-蛋白质-水-细胞内物质的合成与转化●蛋白质------------------------------------------------------------------53-蛋白质的结构域功能简介●DNA的结构-------------------------------------------------------------54 ●水----------------------------------------------------------------------55-实验：测试食物中的营养成分5.酶----------------------------------------------------------------------59●作用机制----------------------------------------------------------------59-酶和温度-酶和pH-酶促反应速率6.植物营养---------------------------------------------------------------66●光合作用----------------------------------------------------------------66-叶片脱色实验-对照实验-光合作用过程-植物的气体交换-光合作用速率的外部影响因素-气孔作用●叶片结构----------------------------------------------------------------77 ●矿物质需求--------------------------------------------------------------81-水培种植7.人体营养---------------------------------------------------------------86●均衡膳食----------------------------------------------------------------86-能量需求-蛋白质需求-素食主义-特殊人群饮食需求-营养不良-全球食物-食物营养主要分类：糖类、脂肪、蛋白质、维生素、无机盐、纤维素（粗粮）、水-营养缺失相关疾病-实验：食物中的能量●消化道------------------------------------------------------------------95-消化道区域和功能-蠕动-霍乱●机械性消化--------------------------------------------------------------98 ●化学性消化-------------------------------------------------------------100 ●吸收-------------------------------------------------------------------103-大肠（盲肠和直肠）-消化实验8.植物的物质运输-------------------------------------------------------110●植物的结构和功能------------------------------------------------------110 ●水分的吸收------------------------------------------------------------114 ●蒸腾作用--------------------------------------------------------------116 ●植物的迁移------------------------------------------------------------1219.动物的物质运输-------------------------------------------------------124-鱼类的血液循环-哺乳动物的双循环●心脏------------------------------------------------------------------125 ●血管和淋巴管----------------------------------------------------------132-淋巴系统●血液------------------------------------------------------------------13610.疾病与免疫-----------------------------------------------------------142-●病原体和传播----------------------------------------------------------142 ●拓展-疟疾-间接接触-水污染-水处理-水排放-家蝇传播-癣-真菌寄生-阿米巴痢疾，变形虫性痢疾●疾病防范--------------------------------------------------------------148-机械隔离-化学障碍-疫苗-抗体和免疫：主动免疫-B、T淋巴细胞-全球旅行-被动免疫-1型糖尿病（遗传或病毒诱发的自身免疫病）●拓展-天花疫苗-巴斯德鹅颈瓶实验11.人体内的气体交换-----------------------------------------------------156●人体气体交换-----------------------------------------------------------156-呼吸系统表面特征-肺的结构-气体交换-肺活量和呼吸速率-实验：呼出气体中的氧气和二氧化碳12.呼吸作用--------------------------------------------------------------165●呼吸作用：体内需能反应------------------------------------------------165 ●有氧呼吸--------------------------------------------------------------165-线粒体●无氧呼吸--------------------------------------------------------------169-实验：呼吸作用和能量释放-拓展：代谢——合成代谢，分解代谢；关于假设13.人体的排泄-----------------------------------------------------------174●排泄------------------------------------------------------------------174-排泄器官：肝，肺，肾，皮肤-肝脏功能-肾脏的显微镜结构-透析：人工肾14.协调与反应-----------------------------------------------------------180●人体的神经系统控制----------------------------------------------------181-神经元-神经冲动-反射弧-拓展-脊髓-反射-突触-突触如何传输电信号●感觉器官--------------------------------------------------------------186-眼睛-视觉-瞳孔反射-眼睛相关结构●人体的激素------------------------------------------------------------190-拓展：甲状腺脑下垂体肾上腺胰腺生殖器官分泌激素●内环境稳态------------------------------------------------------------192-皮肤结构-皮肤功能：保护、敏锐度、体温调节、体温控制-内环境稳态和负反馈调节-血糖调节-1型糖尿病●热带反应--------------------------------------------------------------197-实验：植物的向光性15.药物------------------------------------------------------------------205●药物定义--------------------------------------------------------------205 ●医学药物--------------------------------------------------------------205-抗生素●药物滥用--------------------------------------------------------------207-麻醉药-酒精-怀孕-行为-适度饮酒-吸烟-肺癌-慢性阻塞性肺病-肺气肿-慢性支气管炎-心脏病-被动吸烟-海洛因如何作用于神经系统-吸烟与肺癌之间关联的证据-兴奋剂16.生殖-----------------------------------------------------------------213●无性生殖-------------------------------------------------------------213-真菌的无性生殖-开花植物的无性生殖（营养繁殖）：匍匐茎、根状茎、球茎、球根、块茎-人工授精-扦插-组织培养-动物的无性生殖-无性生殖的优劣势●有性生殖--------------------------------------------------------------219-定义-染色体数目-有性生殖的优劣势-杂交●植物的有性生殖--------------------------------------------------------221-花的结构-授粉：昆虫授粉、风力授粉-适应-实验：花粉管的生长-受精●拓展-发芽-发芽和光照-冬眠-实验：发芽的条件-自交和杂交-受精●拓展-果实和种子的形成●人类的生殖------------------------------------------------------------232-人类的生殖系统-生殖细胞的产生-交配和受精-怀孕和发育-胎盘-产前保健-双胞胎-出生-引产-胎盘和脐带的功能-养育和父母照顾●人体性激素------------------------------------------------------------241-青春期和月经●控制人类出生率的方法--------------------------------------------------243-家庭计划的天然方法-家庭计划的人工方法-化学方法-手术方法●性传播感染疾病--------------------------------------------------------245-控制性传播疾病的蔓延-HIV对免疫系统的作用17.遗传-----------------------------------------------------------------250●遗传定义-------------------------------------------------------------250 ●染色体、基因和蛋白质-------------------------------------------------250-性别的遗传-遗传密码-细胞内蛋白质的产生-基因的表达-染色体的数目●有丝分裂-------------------------------------------------------------254-有丝分裂的过程-实验：醋酸洋红制作染色体装片-染色体的作用-干细胞●减数分裂-------------------------------------------------------------255-配子的产生和染色体●单因子遗传-----------------------------------------------------------259-等位基因-遗传的模式-单因子遗传-基因型和表现型-3:1的比例-测交实验（回交）-共显性和不完全显性-性染色体遗传●拓展-孟德尔：关于遗传的想法18.变异和选择----------------------------------------------------------270●变异-----------------------------------------------------------------270-不连续变异-连续变异-突变-镰刀型细胞贫血症-唐氏综合征-细菌的突变●适应性特征-----------------------------------------------------------274-甲虫、骆驼、北极熊、捕蝇草-干旱环境中的适应-水生环境的适应●选择-----------------------------------------------------------------279-自然选择-竞争与选择-刺蛾-选择育种-进化-自然和人工选择的比较19.生物和他们的生存环境-----------------------------------------------284●能量流动--------------------------------------------------------------284-对阳光的依赖●食物链和食物网--------------------------------------------------------285-食物金字塔-过度捕捉的影响-鱼类过度捕捞-引进外来物种-能量传递-生物量金字塔-物质循环：分解者●营养物质循环----------------------------------------------------------292-碳循环-水循环-氮循环●人口数量--------------------------------------------------------------296-人口数量的变化-人口增长-影响人口增长的因素-群落-生态系统-稳定和增长-人口压力-S型增长曲线20.生物技术和基因工程-------------------------------------------------305●定义-----------------------------------------------------------------305 ●生物技术-------------------------------------------------------------305-生物燃料-面包，面筋-酶-实验：研究蛋白酶在果汁生产中的应用；生物洗衣粉的应用-乳糖不耐受-抗生素-青霉素商业化生产●基因工程-------------------------------------------------------------310-基因工程的应用：人胰岛素的生产、转基因玉米、除虫剂、除草剂-改良的植物产物●拓展：基因工程中应用细菌和限制酶21.人类对生态系统的影响----------------------------------------------316●食物供应------------------------------------------------------------316-农业的加剧-使用化学肥料增加产量-单一栽培和其负面影响-农药：杀虫剂和除草剂-选择育种-过度养殖家畜的负面影响-全球食物供应的问题●栖息地破坏---------------------------------------------------------320-栖息地的搬迁-自然资源的开采-海洋污染-植被砍伐-森林和气候●污染---------------------------------------------------------------324-杀虫剂-除草剂-核设备发生的故障-化学废弃物-垃圾丢弃-污水排放-化肥使用：富营养化-温室效应和全球变暖-塑料和环境-空气污染-二氧化硫和氧化氮-空气污染的控制-保护臭氧层-避孕激素的污染（影响生殖和性别比例）●保护---------------------------------------------------------------334-循环利用-污水处理-濒危物种和灭绝原因-物种保护-人工养殖和再引进-种子库-栖息地保护-可持续发展：番茄鱼项目-保护计划-保存生态系统功能●配套章节练习-------------------------------------------------------347 ●计算题答案---------------------------------------------------------384 ●索引---------------------------------------------------------------385 ✧。

Chapter_01_cell basics

-Genes provide the instructions for cellular form, function, and complex behavior
Figure 1-1 Essential Cell Biology (© Garland Science 2010)
Figure 1-2 Essential Cell Biology (© Garland Science 2010)
Figure 1-23 Essential Cell Biology (© Garland Sciencsential Cell Biology (© Garland Science 2010)
Figure 1-25 Essential Cell Biology (© Garland Science 2010)
-Prokaryotes are the most diverse of cells
In shape and structure prokaryotes may seem simple and limited, but in terms of chemistry they are the most diverse and inventive class of cells. ---habitats, aerobic/anaerobic, organic/inorganic substrate, photosynthesis
Endocytosis, Exocytosis
-The cytosol is a concentrated aqueous gel of large and small molecules
breakdown of nutrient molecules synthesis of proteins (ribosomes)

Bc science 10 Chapter 1(加拿大bc省科学十年级第一节词汇)

abioticrelating to non-living parts of an environment such as sunlight, soil, moisture, and temperatureadaptationscharacteristics that enable organisms to better survive and reproducebehavioural adaptationwhat an organism does to survive in the unique conditions of its environmentbiodiversitythe diversity of plant, animal life and micro-organisms in a particular habitat (or in the world as a whole)biomethe largest division of the biosphere, which includes large regions with similar biotic components and similar abiotic componentsbiospherethe thin layer of air, land and water on or near Earth's surface in which all living things on Earth existbioticrelating to living organisms such as plants, animals, fungi and bacteriaclimatethe average conditions of the atmosphere. for example precipitation, temperature and humidity in a large region over 30 years of moreclimatographa graph of climate data for a specific region; the data are usually obtained over 30 years from local weather observation stationscommensalisma symbiotic relationship in which one species benefits and the other species is neither helped nor harmedcommunityall the populations of the different species that interact in a specific area or ecosystemcompetitiona harmful interaction between two or more organisms that can occur when organisms compete for the same resource in the same location at the same timeecological hierarchythe order of biotic interactions and relationships in an ecosystem: organism, population, community, ecosystemecosystema part of a biome in which abiotic components interact with biotic componentselevationthe height of a land mass above sea levelhabitatthe place in which an organism liveslatitudethe distance measured in degrees north or south from the equatormutualisma symbiotic relationship between two organism in which both organisms benefitnichethe special role an organism plays in an ecosystem, including the way in which it contributes to and fits its environmentparasitismthe relation between two different kinds of organisms in which one receives benefits from the other by causing damage to it (usually not fatal damage)physiological adaptationa physical or chemical event that occurs within the body of an organism and enables survivalpopulationthe members of a particular species within an ecosystempredationpredator-prey interactions in which one organism (the predator) eats all or part of another organism (the prey)speciesa group of closely related organisms that can reproduce with one anotherstructural adaptationa physical feature of an organism's body having a specific function that contributes to the survival of the organismsymbiosisthe interaction between members of two different species that live together in a close association。

horrible science pdf 英文版

horrible science pdf 英文版Title: Horrible Science PDF English Version: A Comprehensive ReviewIntroduction:Horrible Science is a popular educational series that aims to make science fun and engaging for children. In this article, we will provide a comprehensive review of the Horrible Science PDF English version. The review will be structured as follows: an overview, five major points, each containing 3-5 subpoints, and a conclusion.Overview:The Horrible Science PDF English version offers a wealth of knowledge and captivating content for young readers. It covers a wide range of scientific topics, presented in an entertaining and accessible manner. The following points will delve into the specific aspects of the Horrible Science PDF English version.1. Engaging Content:1.1 Entertaining narratives: The Horrible Science PDF English version presents scientific concepts through humorous and engaging stories, making it easy for children to understand and retain information.1.2 Fascinating experiments: The PDF includes step-by-step instructions for exciting experiments that allow children to explore scientific principles in a hands-on manner.1.3 Interactive illustrations: The inclusion of interactive illustrations enhances the learning experience, enabling children to visualize scientific concepts more effectively.2. Comprehensive Scientific Topics:2.1 Biology: The Horrible Science PDF English version covers various biological topics, such as the human body, animals, and plants, providing detailed explanations and interesting facts.2.2 Chemistry: Children can learn about chemical reactions, elements, and compounds through engaging examples and experiments.2.3 Physics: The PDF introduces basic physics principles, including gravity, forces, and energy, with clear explanations and relatable examples.2.4 Earth Sciences: Topics such as geology, weather, and the environment are covered, fostering an understanding of the world around us.2.5 Astronomy: The Horrible Science PDF English version also includes captivating information about space, planets, and the universe, sparking curiosity about the cosmos.3. Educational Value:3.1 Simplified explanations: Complex scientific concepts are broken down into digestible explanations, ensuring that children grasp the fundamental ideas.3.2 Real-world applications: The PDF connects scientific knowledge to real-life scenarios, enabling children to understand the practical applications of what they learn.3.3 Stimulates curiosity: The Horrible Science PDF English version encourages children to ask questions and explore further, fostering a lifelong love for learning and scientific inquiry.4. Age Appropriateness:4.1 Suitable for various age groups: The Horrible Science PDF English version is designed to cater to different age ranges, ensuring that the content is accessible and engaging for all.4.2 Gradual complexity: The series progresses from basic concepts to more advanced topics, allowing children to build their scientific knowledge gradually.5. Accessibility and Portability:5.1 Digital format: The Horrible Science PDF English version offers the convenience of digital access, allowing children to read and explore scientific concepts on various devices.5.2 Portable: The PDF format enables children to carry the entire collection of Horrible Science books in a compact and lightweight form, making it ideal for travel or on-the-go learning.Conclusion:The Horrible Science PDF English version provides an excellent resource for children to learn and explore various scientific topics. With engaging content, comprehensive coverage, educational value, age appropriateness, and accessibility, it is a valuable tool for both educators and young learners. By making science enjoyable and accessible, Horrible Science encourages children to develop a lifelong interest in the subject.。

英文科学百科全书

英文科学百科全书The universe is a vast expanse of stars and planets, each with its own unique characteristics and stories to tell. It's a place where science and wonder intertwine, inviting us to explore the mysteries of the cosmos.From the smallest atom to the largest galaxy, science has been unraveling the intricacies of our natural world. It's a journey that starts with the basics of matter and energy, leading us to the complex dance of celestial bodies.Biology, a branch of science, delves into the world of living organisms, revealing the marvels of evolution and the interconnectedness of life. It's a study that teaches us about the resilience and adaptability of species across the globe.Chemistry, on the other hand, is the science of elements and compounds. It's about understanding how substances interact and transform, the building blocks of everything from the air we breathe to the food we eat.Physics takes us to the heart of matter and motion, explaining the fundamental forces that govern the universe. It's a field that challenges our perceptions of time and space, and the laws that keep the stars in their courses.The study of Earth's sciences, including geology andmeteorology, helps us understand the planet we call home. From the shifting tectonic plates to the changing climate, these sciences are crucial for our survival and well-being.Innovations in technology and engineering are the practical applications of science. They bridge the gap between theory and practice, transforming our lives with new inventions and solutions to global challenges.Finally, the pursuit of scientific knowledge is a never-ending quest. It's a journey that requires curiosity, creativity, and a relentless drive to push the boundaries of what we know and understand.Together, these scientific disciplines form the backbone of our understanding of the world, inviting us to delve deeper into the enigma of existence and the laws that govern it.。

不列颠百科全书英文版

不列颠百科全书英文版The English version of the Encyclopedia Britannica is a comprehensive reference work that provides information on a wide range of topics. It covers various subjects including history, science, literature, arts, geography, and more.The Encyclopedia Britannica is known for its rigorous editorial standards and authoritative content.The English edition of the Encyclopedia Britannica is organized alphabetically, allowing readers to easily find information on specific topics. Each entry in the encyclopedia provides a detailed and comprehensive overview of the subject matter, often including historical context, key figures, and important events.The Encyclopedia Britannica is regularly updated to reflect the latest research and discoveries in various fields. It is a valuable resource for students, researchers, and anyone seeking reliable and in-depth information.In addition to its print version, the Encyclopedia Britannica also has an online edition, which provides access to a vast amount of information. The online edition includes multimedia content such as images, videos, and interactive features, enhancing the learning experience.Overall, the English version of the Encyclopedia Britannica is a trusted and authoritative source of knowledge, offering comprehensive and detailed information on a wide range of subjects.。

Chapter2BC.–450BC

SLIDE 1Chapter 2Early River Valley Civilizations, 3500 B.C.–450 B.C.Civilizations emerge and develope on fertile river plains in Mesopotamia, Egypt, the Indus Valley, and China.SLIDE 2Section 1: City-States in MesopotamiaSection 2: Pyramids on the NileSection 3: Planned Cities on the IndusSection 4: River Dynasties in ChinaSLIDE 3Section 1: City-States in MesopotamiaThe earliest civilization in Asia rises in Mesopotamia and organizes into city-states. SLIDE 4Section 1: City-States in MesopotamiaGeography of the Fertile CrescentThe Fertile Crescent•Fertile Crescent arc of land between Persian Gulf and Mediterranean •Includes Mesopotamia—“land between the rivers”—a fertile plain•Tigris and Euphrates rivers flood once a year, leaving rich soilSLIDE 5Continued Geography of the Fertile CrescentEnvironmental Challenges•Around 3300 B.C. Sumerians begin farming southern Mesopotamia •Environment poses three disadvantages:- floods are unpredictable; sometimes no rain- land offers no barriers to invasion- land has few natural resources; building materials scarceSLIDE 6Continued Geography of the Fertile CrescentSolving Problems Through Organization•Sumerians work together; find solutions to environmental challenges: - build irrigation ditches to control water, produce crops- build walled cities for defense- trade grain, cloth, and tools for raw materials—stone, wood, metal •Organization, leadership, and laws are beginning of civilizationSLIDE 7Sumerians Create City-StatesSumerian City-States•By 3000 B.C. Sumerians build cities surrounded by fields of crops •Each is a city-state an independent political unit•Sumer city-states: Uruk, Kish, Lagash, Umma, and Ur•Each city has temple and ziggurat; priests appeal to godsSLIDE 8Continued Sumerians Create City-StatesPriests and Rulers Share Control•Sumer’s early governments controlled by temple priests•Some military leaders become rulers; dynasties rule after 2500 B.C.•Dynasty—series of rulers from a single familyThe Spread of Cities•By 2500 B.C. many new cities in Fertile Crescent•Sumerians exchange products and ideas with other cultures •Cultural diffusion—process of one culture spreading to othersSLIDE 9Sumerian CultureA Religion of Many Gods•Sumerians believe in many different gods—polytheism•Gods are thought to control forces of nature•Gods behave as humans do, but people are gods’ servants•Life after death is bleak and gloomyLife in Sumerian Society•Sumerians have social classes kings, landholders, priests at top •Wealthy merchants next; at lowest level are slaves•Women have many rights; become priests, merchants, artisans SLIDE 10Continued Sumerian CultureSumerian Science and Technology•Sumerians invent wheel, sail, and plow; first to use bronze•Make advances in arithmetic and geometry•Develop arches, columns, ramps, and pyramids for building•Have a complex system of writing—cuneiform•Study astronomy, chemistry, medicineSLIDE 11The First Empire BuildersTime of War•From 3000 to 2000 B.C. city-states at constant warSargon of Akkad•Around 2350 B.C., Sargon from Akkad defeats city-states of Sumer •Creates first empire—independent states under control of one leader •His dynasty lasts about 200 yearsBabylonian Empire•Amorites, nomadic warriors, take control of region around 2000 B.C.•Make Babylon, on Euphrates River, the capital•Babylonian Empire at peak during Hammurabi’s rule (1792–1750 B.C.) SLIDE 12Continued The First Empire BuildersHammurabi’s Code•Hammurabi creates a code of laws for the Babylonian Empire•282 laws on all aspects of life; engraved in stone and made public •Set different punishments depending on social class, gender•Goal is for government to take responsibility for order, justice •Amorite rule of Fertile Crescent ends 200 years after Hammurabi SLIDE 13Section 2: Pyramids on the NileUsing mathematical knowledge and engineering skills, Egyptians build magnificent monuments to honor dead rulers.SLIDE 14Section 2: Pyramids on the NileThe Geography of EgyptEgypt’s Settlements•Arise along the 4,100-mile Nile River on narrow strip of fertile landThe Gift of the Nile•Yearly flooding brings water and fertile black mud—silt•Farmers build irrigation system for wheat and barley crops•Egyptians worship Nile as a godSLIDE 15Continued The Geography of EgyptEnvironmental Challenges•Light floods reduce crops, cause starvation•Heavy floods destroy property; deserts isolate and protect EgyptiansUpper Egypt and Lower Egypt•River area south of First Cataract is elevated, becomes Upper Egypt •Cataract—where boulders turn Nile River into churning rapids•River area north, including Nile delta, becomes Lower Egypt•Delta—land formed by silt deposits at mouth of river; triangularSLIDE 16Egypt Unites into a KingdomKing Narmer Creates Egyptian Dynasty•Villages of Egypt ruled by two kingdoms—Lower Egypt, Upper Egypt•King Narmer unites them around 3000 B.C.; makes Memphis capital •Establishes first Egyptian dynastyPharaohs Rule as Gods•To the Egyptians, kings are gods; Egyptian god-kings called pharaohs •Pharaohs control religion, government, army, well-being of kingdom •Government based on religious authority theocracySLIDE 17Continued Egypt Unites into a KingdomBuilders of the Pyramids•Kings believed to rule even after death; have eternal life force, ka •Build elaborate tombs, pyramids, to meet needs after death •Pyramids made with blocks of stone, 2−15 tons each; 481 ft. high•Kingdom had leadership, government; economically strongSLIDE 18Egyptian CultureReligion and Life•Egyptians believe in 2,000 gods and goddesses—polytheistic•Re is sun god; Osiris, god of the dead; goddess Isis is ideal woman •Believe in life after death; person judged by deeds at death •Develop mummification, process that prevents body from decaying •Book of the Dead contains prayers and spells, guides soul after death SLIDE 19Life in Egyptian SocietySocial Classes•Society shaped like pyramid, from pharaoh down to farmers, laborers •Few people at top have great power; most people at bottom •People move into higher social classes through marriage or merit •Women have many of the same rights as menEgyptian Writing•In hieroglyphics writing system, pictures represent ideas •Paperlike sheets made from papyrus reeds used for writingSLIDE 20Continued Life in Egyptian SocietyEgyptian Science and Technology•Egyptians invent calendar of 365 days and 12 months•Develop system of written numbers and a form of geometry •Skilled engineers and architects construct palaces, pyramids •Egyptian medicine famous in the ancient worldSLIDE 21Invaders Control EgyptChanges to Egyptian Society•Power of pharaohs declines about 2180 B.C.; end of Old Kingdom•In Middle Kingdom (2040 to 1640 B.C.), some pharaohs regain control •Improve trade, dig canal from Nile to Red Sea, drain swamps for farms •Hyksos move into Egypt from Palestine; rule from 1630 to 1523 B.C.SLIDE 22Section 3: Planned Cities on the IndusThe first Indian civilization builds well-planned cities on the banks of the Indus River.SLIDE 23Section 3: Planned Cities on the IndusThe Geography of the Indian SubcontinentIndian Subcontinent•Subcontinent—landmass that includes India, Pakistan, and Bangladesh •World’s tallest mountain ranges separate it from rest of AsiaRivers, Mountains, and Plains•Mountains to north, desert to east, protect Indus Valley from invasion•Indus and Ganges rivers form flat, fertile plain—the Indo-Gangetic•Southern India, a dry plateau flanked by mountains•Narrow strip of tropical land along coastSLIDE 24Continued The Geography of the Indian SubcontinentMonsoons•Seasonal winds—monsoons—dominate India’s climate•Winter winds are dry; summer winds bring rain—can cause floodingEnvironmental Challenges•Floods along the Indus unpredictable; river can change course•Rainfall unpredictable; could have droughts or floodsSLIDE 25Civilization Emerges on the IndusIndus Valley Civilization•Influenced an area larger than Mesopotamia or EgyptEarliest Arrivals•About 7000 B.C., evidence of agriculture and domesticated animals •By 3200 B.C., people farming in villages along Indus RiverPlanned Cities•By 2500 B.C., people build cities of brick laid out on a grid system •Engineers create plumbing and sewage systems•Indus Valley called Harappan civilization after Harappa, a citySLIDE 26Continued Civilization Emerges on the IndusHarappan Planning•City built on mud-brick platform to protect against flood waters •Brick walls protect city and citadel—central buildings of the city •Streets in grid system are 30 feet wide•Lanes separate rows of houses (which featured bathrooms)SLIDE 27Harappan CultureLanguage•Had writing system of 400 symbols, but scientists can’t decipher itCulture•Harappan cities appear uniform in culture; no great social divisions •Animals important to the culture; toys suggest prosperitySLIDE 28Continued Harappan CultureRole of Religion•Priests closely linked to rulers•Some religious artifacts reveal links to modern Hindu cultureTrade•Had thriving trade with other peoples, including in MesopotamiaSLIDE 29Indus Valley Culture EndsHarappan Decline•Signs of decline begin around 1750 B.C.•Earthquakes, floods, soil depletion may have caused decline•Around 1500 B.C., Aryans enter area and become dominantSLIDE 30Section 4: River Dynasties in ChinaEarly rulers introduce ideas about government and society that shape Chinese civilization.SLIDE 31Section 4: River Dynasties in ChinaThe Geography of ChinaBarriers Isolate China•Ocean, mountains, deserts isolate China from other areasRiver Systems•Huang He (“yellow river”) in north, Yangtze in south•Huang He leaves loess—fertile silt—when it floodsEnvironmental Challenges•Huang He floods can devour whole villages•Geographic isolation means lack of trade; must be self-sufficientChina’s Heartland•North China Plain, area between two rivers, center of civilizationSLIDE 32Civilization Emerges in Shang TimesThe First Dynasties•Around 2000 B.C cities arise; Yu, first ruler of Xia Dynasty•Yu’s flood control system tames Huang He (“Yellow River”)•Shang Dynasty, 1700 to 1027 B.C., first to leave written recordsEarly Cities•Built cities of wood, such as Anyang—one of its capital cities•Upper classes live inside city; poorer people live outside•Shang cities have massive walls for military defenseSLIDE 33The Development of Chinese CultureChinese Civilization•Sees China as center of world; views others as uncivilized•The group is more important than the individualFamily•Family is central social institution; respect for parents a virtue •Elder males control family property•Women expected to obey all men, even sonsSocial Classes•King and warrior-nobles lead society and own the landSLIDE 34Continued The Development of Chinese CultureReligious Beliefs•Spirits of dead ancestors can affect family fortunes•Priests scratch questions on animal bones and tortoise shells •Oracle bones used to consult gods; supreme god, Shang DiDevelopment of Writing•Writing system uses symbols to represent syllables, not ideas •People of different languages can use same system•Huge number of characters make system difficult to learnSLIDE 35Zhou and the Dynastic CycleThe Zhou Take Control•In 1027 B.C., Zhou Dynasty takes control of ChinaMandate of Heaven•Mandate of Heaven—the belief that a just ruler had divine approval •Developed as justification for change in power to Zhou •Dynastic cycle—pattern of the rise and decline of dynastiesControl Through Feudalism•Feudalism—system where kings give land to nobles in exhange for services •Over time, nobles grow in power and begin to fight each otherSLIDE 36Continued Zhou and the Dynastic CycleImprovements in Technology and Trade•Zhou Dynasty builds roads, canals to improve transportation•Uses coins to make trade easier•Produces cast iron tools and weapons; food production increasesA Period of Warring States•Peaceful, stable Zhou empire rules from around 1027 to 256 B.C.•In 771 B.C., nomads sack the Zhou capital, murder monarch•Luoyang becomes new capital, but internal wars destroy traditions。

选择性必修二Unit1 Science and Scientists课外资料

人教版高中英语选择性必修二课外阅读文章Chinese scientist wins 2015 Nobel Prize（译林版）Tu Youyou has become the first female Chinese scientist to receive a Nobel Prize, awarded for her contribution to the fight against malaria, one of the deadliest diseases in human history. Thanks to her discovery of qinghaosu, malaria patients all over the world now have had a greatly increased chance of survival.Born in 1930, in Ningbo, Zhejiang Province, Tu studied medicine at university in Beijing between 1951 and 1955. After graduation, she worked at the Academy of Traditional Chinese Medicine. She completed further training courses in traditional Chinese medicine, acquiring a broad knowledge of both Chinese and Western medicine.Tu’s education was soon to prove very useful. In the 1960s, many people were dying of malaria, and in 1969 Tu became head of a team that intended to find a cure for the disease. She collected over 2,000 traditional Chinese medicine recipes for malaria treatment and made hundreds of extracts from different herbs. When they failed to produce any promising results, Tu referred to the ancient books of traditional Chinese medicine again. Inspired by a 1,700-year-old text about preparing qinghao with cold water, Tu redesigned the experiments and tried extracting the herb at a low temperature in order not to damage its effective part. On 4 October 1971, after 190 failures, she succeeded in making a qinghao extract that could treat malaria in mice.However, it was hard to produce enough qinghao extract for large trials because research resources and good equipment were limited. Tu and her team managed to find solutions to the problem. When there was no research equipment, they had to put qinghao into household water containers. They worked day and night and their health began to suffer because of the poor conditions, but they never gave up.Even with large amounts of the qinghao extract produced, however, they still faced another problem. The trials on real patients were likely to be postponed because they did not have sufficient data. To speed up the process and ensure its safety, Tu and her team volunteered to test the qinghao extract on themselves first.The efforts of Tu and her team finally paid off. In November 1972, they successfully isolated the most effective part of the extract and named it qinghaosu --- a pure, stronger qinghao extract which is now a key part of many malaria medicines. Qinghaosu has since benefited about 200 million people. More than 40 years after its discovery, Tu was eventually awarded the Nobel Prize for her work. In her Nobel Lecture, she encouraged scientists to further explore the treasure house of traditional Chinese medicine and raise it to a higher level. Perhaps the next generation of scientists, drawing on the wisdom of traditional Chinese medicine, will indeed discover more medicines beneficial to global health care.Stephen Hawking（北师大版）On 14 March, 2018, one of the world’s most influential scientists, Stephen Hawking, died at his home in England, aged 76. Hawking was famous, not just for his brilliant work in theoretical physics and cosmology, but also for overcoming the challenges of ALS(a disease that affects muscle control).Stephen Hawking was born on 8 January, 1942, in Oxford. He went to the University of Oxford to study physics in 1959. At the age of 21, when Hawking spent his first year at the University of Cambridge, physicians discovered he had a rare, slow-progressing form of ALS. He was onlyexpected to live for a few years.Hawking later found a job at the Institute of Astronomy in Cambridge. In the early stages of his career, his illness got worse, but he was allowed to do research only rather than teach, which was easier for him. In 1985, he had to have an operation. As a result, he lost his speech. Soon his doctors developed a piece of speech-generating equipment that allowed him to speak. However, as his illness became worse, he lost the use of his hands.Although Hawking’s physical abilities declined over decades, he never ceased his studies and he developed a number of new ideas about black holes. Hawking believed that the birth of the universe (the “Big Bang”) created many small black holes. His theory was that there was a sort of hole in the centre of a black hole. This hole led to another universe, completely separate from our own.Hawking also wrote books. His 1988 book, A Brief History of Time: From the Big Bang to Black Holes, sold one copy for every 750 people on earth. However, many people could not really understand what he had written. Therefore, Hawking decided to write a simpler version, A Brief History of Time(2005).In The Grand Design (2010, with Leonard Mlodinow), Hawking argued that we should look for a different way to discover the deepest secrets of the universe. Instead of trying to find one big new explanation, scientists should put together all the ideas that they already have.At the opening of the London 2012 Olympics, Hawking said to a TV audience of 900 million people: “Look up at the stars and not down at your feet…be curious.”In spite of his disease, Hawking didn’t consider himself an unlucky man. He said it had not prevented him from having a family, and being successful in his work. “My expectations were reduced to zero when I was 21. Everything since then has been a bonus.” And he believed this was because of the help he received from his family and a large number of people and organisations.A profile of Elon Musk（北师大版）Elon Musk is a businessman, inventor and engineer and is undoubtedly, one of the leading figures in the world of technology. Must was born in Pretoria, South Africa in 1971. A gifted child, he taught himself how to programme computers at the age of 12. He was accepted to university in the United States where he completed a degree in Arts. After this, he started a PhD in physics at Stanford University, California. However, he dropped out to pursue his interest in startups and technology.He continued working in the field of technology, in particular founding an online payment site that eventually would become a global company. In 2001 Musk, who had an interest in space exploration, began meeting with scientists to discuss the possibility of human habitation on Mars. He believed that space travel could be both affordable and available for the masses. Using his own fortune, Musk founded his company that designs rockets and space vehicles. It was the first privately owned company to do so, as prior to this, almost all space technology was designed by governments. In 2012, the rockets made by the company docked with the International Space Station. Musk also received contracts from NASA and the US space agency, thus making history by proving that the concept of commercial space exploration was both possible and affordable.Another one of Musk’s innovations is the electric car. To create electric cars, Musk started a company and became the CEO in 2008. The company is named after Nicolai Tesla, the Serbian-American inventor and physicist, who is best known for designing the AC electrical system. The cars made by Musk’s company are designed to end the dependence on fossil fuels and so reduce thenegative effects of climate change and air pollution from cars.Musk’s motivation for his innovations are to expand human reach in the universe and protect the resources of our planet. By creating opportunities to explore new planets, Musk believes that in the event of a major catastrophe on Earth, there would be the potential for the human race to continue elsewhere. On Earth, Must’s inventions are designed to find renewable, environment-friendly solutions to meet the challenge of an ever-growing global population that demands energy and transport. According to Musk, “I came to the conclusion that we should aspire to increase the scope and scale of human consciousness in order to better understand what questions to ask. Really, the only thing that makes sense is to strive for greater collective enlightenment.”。

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

Bioaccumulation "the gradual build-up of synthetic and organic chemicals in living organisms" Biodegredation "the breaking down of dead organic matter by living organisms such as bacteria" Biomagnification "the process in which chemicals not only accumulate but become more concentrated at each trophic level in a food pyramid"biomass "the total mass of living matter in a given unit area"bioremediationthe act of treating waste or pollutants by the use of microorganisms (as bacteria) or plants that can break down the undesirable substances such as chemical pollutants to reverse or lessen environmental damageCarbonate a combination of carbon and oxygen that is dissolved in ocean waterCarnivores secondary consumers that eat primary consumers and often other secondary consumers. They are often at the tertiary level of a food chain; also known as top carnivores (e.g. Cougar, Polar Bear)cellular respirationthe process in which both plants and animals release carbon dioxide back into the atmosphere by converting carbohydrates and oxygen into carbon dioxide and waterconsumeran organism that eats other organismscontaminationthe introduction of chemicals, toxins, wastes, or micro-organisms into the environment in concentrations that are harmful to living thingsDDTan insecticide and well-known persistent organic pollutant, now banned in many countries (used to kill weeds but causes cancer)decomposersorganisms that break down wastes and dead organisms and change them into usable nutrients available to other organismsdecompositionin biology, the breaking down of organic wastes and dead organismsdenitrificationthe process in which nitrogen is returned to the atmospheredenitrifying bacteriabacteria that convert nitrate back into nitrogen gasdetrivoresconsumers that feed at every trophic level, obtaining their energy and nutrients by eating deadorganic matterecological pyramida food pyramid. There are three types of ecological pyramids: pyramid of biomass, pyramid of numbers, and pyramid of energyenergy flowthe flow of energy from an ecosystem to an organism and from one organism to anothereutrophicationprocess by which a body of water becomes too rich in dissolved nutrients, leading to plant growth that depletes oxygenfood chaina model that shows the flow of energy from plant to animal and from animal to animalfood pyramida model that shows the loss of energy from one trophic level to another; often called an ecological pyramidfood weba model of the feeding relationships within an ecosystem; formed from interconnected food chainsgeologic upliftthe process of mountain building in which Earth's crust folds and deeply buried rock layers rise and are exposedheavy metalsmetallic elements with a high density that are toxic to organisms at low concentrationsherbivoresprimary consumers that eat plantskeystone speciesspecies that can greatly affect population numbers and the health of an ecosystemleachingremoval by water of substances that have dissolved in moist soilnitrificationammonium is converted into nitratenitrifying bacteriaBacteria that change dissolved ammonia into nitrite compounds or nitrites into nitrate compounds.nitrogen cyclethe nutrient cycle in which nitrogen is moved through the biospherenitrogen fixationnitrogen gas is converted into compounds that contain nitrate or ammoniumnitrogen-fixing bacteriabacteria that convert nitrogen gas into ammonium during decomposition, playing a significant role in nitrogen fixationnutrient cyclesInclude the Carbon cycle, the Nitrogen cycle, and the Phosphorus cycle : required by plants and animals for energy, growth, development, repaire or maintenancenutrientssubstances such as the chemicals nitrogen and phosphorus that are required by plants and animals for energy, growth, development, repair, or maintenanceomnivoresconsumers that eats both plants and animalsparts per milliona measurement of chemical accumulation; 1 ppm means one particle mixed with 999 999 other particlesPCBssynthetic chemicals containing chlorine that are used in the manufacture of plastics and other industrial products, become stored in the tissue of animals, and also persist in the environmentPOPscarbon-containing compounds that remain in water and soil for many yearspesticidesany one of various substances used to kill harmful insects (insecticide), fungi (fungicide), vermin, or other living organisms that destroy or inhibit plant growth, carry disease, or are otherwise harmful.phosphorus cyclethe nutrient cycle in which phosphorus is moved through the biospherephotosynthesisprocess by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starchesprimary consumersorganisms in the second trophic level which obtain their energy by eating primary producersprimary producersorganisms in the first trophic level, such as plants and algaeprimary successionthe development of new life in areas where no organisms or soil previously existed, such as on bare rock; the first organisms may be lichen spores carried by windsproducersorganisms that produce food in the form of carbohydrates during photosynthesispyramid of biomassShows the total amount of living material available at each trophic level multiplied by their masspyramid of energyeach step represents a transfer of energy (only 10% of energy is transferred from level to level)pyramid of numbersrepresentation of the number of individual organisms in each trophic level of an ecosystemsecondary consumersorganisms in the third trophic level, which obtain their energy by eating primary consumerssedimentationthe process in which soil particles and decaying organic matter accumulate in layers on the ground or at the bottom of large bodies of water, contributing to the formation of sedimentary rockstoresnutrients that are accumulated for short or long periods of time in Earth's atmosphere, oceans, and land massestertiary consumersorganisms in the fourth trophic level, which obtain their energy by eating secondary consumerstrophic levelssteps in a good chain that show the feeding and niche relationships among organismsWeatheringThe Process of breaking down rock into smaller fragments. Chemical weathering and Physical W are two types of weathering involved in the phosphorus cycleCarbon Cyclethe nutrient cycle in which carbon is moved through the biosphere; maintains the balance of CO2 in the atmosphereHalf - lifethe time it take for a living tissue, organ, organism or ecosystem to eliminate one half of a substance that has been introduced into it.。