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Collaborative Governance in Theory and Practice
JPART18:543–571 Collaborative Governance in Theoryand PracticeChris AnsellAlison GashUniversity of California,BerkeleyABSTRACTOver the past few decades,a new form of governance has emerged to replace adversarial and managerial modes of policy making and implementation.Collaborative governance,as it has come to be known,brings public and private stakeholders together in collective forums with public agencies to engage in consensus-oriented decision making.In this article, we conduct a meta-analytical study of the existing literature on collaborative governance with the goal of elaborating a contingency model of collaborative governance.After review-ing137cases of collaborative governance across a range of policy sectors,we identify critical variables that will influence whether or not this mode of governance will produce successful collaboration.These variables include the prior history of conflict or cooperation, the incentives for stakeholders to participate,power and resources imbalances,leadership, and institutional design.We also identify a series of factors that are crucial within the collaborative process itself.These factors include face-to-face dialogue,trust building,and the development of commitment and shared understanding.We found that a virtuous cycle of collaboration tends to develop when collaborative forums focus on‘‘small wins’’that deepen trust,commitment,and shared understanding.The article concludes with a discus-sion of the implications of our contingency model for practitioners and for future research on collaborative governance.Over the last two decades,a new strategy of governing called‘‘collaborative governance’’has developed.This mode of governance brings multiple stakeholders together in common forums with public agencies to engage in consensus-oriented decision making.In this article,we conduct a meta-analytical study of the existing literature on collaborative governance with the goal of elaborating a general model of collaborative governance. The ultimate goal is to develop a contingency approach to collaboration that can highlight conditions under which collaborative governance will be more or less effective as an Early versions of this article were presented at the Conference on Democratic Network Governance,Copenhagen,the Interdisciplinary Committee on Organizations at the University of California,Irvine,and the Berkeley graduate seminar Perspectives on Governance.We thank the participants of these events for their useful suggestions and Martha Feldman,in particular,for her encouragement.We also thank two anonymous reviewers for their thoughtful and useful comments.Address correspondence to the author at cansell@ or aligash@.doi:10.1093/jopart/mum032Advance Access publication on November13,2007ªThe Author2007.Published by Oxford University Press on behalf of the Journal of Public Administration Researchand Theory,Inc.All rights reserved.For permissions,please e-mail:journals.permissions@approach to policy making and public management.1In conducting this meta-analytic study,we adopted a strategy we call ‘‘successive approximation’’:we used a sample of the literature to develop a common language for analyzing collaborative governance and then successively ‘‘tested’’this language against additional cases,refining and elaborating our model of collaborative governance as we evaluated additional cases.Although collaborative governance may now have a fashionable management cache´,the untidy character of the literature on collaboration reflects the way it has bubbled up from many local experiments,often in reaction to previous governance failures.Collabo-rative governance has emerged as a response to the failures of downstream implementation and to the high cost and politicization of regulation.It has developed as an alternative to the adversarialism of interest group pluralism and to the accountability failures of manageri-alism (especially as the authority of experts is challenged).More positively,one might argue that trends toward collaboration also arise from the growth of knowledge and in-stitutional capacity.As knowledge becomes increasingly specialized and distributed and as institutional infrastructures become more complex and interdependent,the demand for collaboration increases.The common metric for all these factors may be,as Gray (1989)has pointed out,the increasing ‘‘turbulence’’faced by policy makers and managers.Although Susskind and Cruikshank (1987),Gray (1989),and Fung and Wright (2001,2003)have suggested more general theoretical accounts of collaborative governance,much of the literature is focused on the species rather than the genus .The bulk of the collaborative governance literature is composed of single-case case studies focused on sector-specific governance issues like site-based management of schools,community po-licing,watershed councils,regulatory negotiation,collaborative planning,community health partnerships,and natural resource comanagement (the species).2Moreover,a num-ber of the most influential theoretical accounts of this phenomenon are focused on specific types of collaborative governance.Healey (1996,2003)and Innes and Booher (1999a,1999b),for example,provide foundational accounts of collaborative planning,as Freeman (1997)does for regulation and administrative law and Wondolleck and Yaffee (2000)do for natural resources management.Our goal is to build on the findings of this rich literature,but also to derive theoretical and empirical claims about the genus of collaborative governance—about the common mode of governing.DEFINING COLLABORATIVE GOVERNANCEWe define collaborative governance as follows:A governing arrangement where one or more public agencies directly engage non-state stakeholders in a collective decision-making process that is formal,consensus-oriented,and deliberative and that aims to make or implement public policy or manage publicprograms or assets.This definition stresses six important criteria:(1)the forum is initiated by public agencies or institutions,(2)participants in the forum include nonstate actors,(3)participants engage directly in decision making and are not merely ‘‘consulted’’by public agencies,(4)the 1Thomas (1995)develops a contingency perspective on public participation,though it aims more broadly and is developed from the perspective of public managers.2A smaller group of studies evaluates specific types of collaborative governance at a more aggregated level (for example,see Beierle [2000],Langbein [2002],and Leach,Pelkey,and Sabatier [2002]).Journal of Public Administration Research and Theory544Ansell and Gash Collaborative Governance in Theory and Practice545 forum is formally organized and meets collectively,(5)the forum aims to make decisionsby consensus(even if consensus is not achieved in practice),and(6)the focus of collab-oration is on public policy or public management.This is a more restrictive definition thanis sometimes found in the literature.However,the wide-ranging use of the term has,as Imperial notes,been a barrier to theory building(Imperial2005,286).Since our goal is to compare apples with apples(to the extent possible),we have defined the term restrictivelyso as to increase the comparability of our cases.One critical component of the term collaborative governance is‘‘governance.’’Much research has been devoted to establishing a workable definition of governance that is bounded and falsifiable,yet comprehensive.For instance,Lynn,Heinrich,and Hill (2001,7)construe governance broadly as‘‘regimes of laws,rules,judicial decisions,and administrative practices that constrain,prescribe,and enable the provision of publicly supported goods and services.’’This definition provides room for traditional governmental structures as well as emerging forms of public/private decision-making bodies.Stoker,onthe other hand,argues:As a baseline definition it can be taken that governance refers to the rules and forms that guidecollective decision-making.That the focus is on decision-making in the collective impliesthat governance is not about one individual making a decision but rather about groups ofindividuals or organisations or systems of organisations making decisions(2004,3).He also suggests that among the various interpretations of the term,there is‘‘baseline agreement that governance refers to the development of governing styles in which bound-aries between and within public and private sectors have become blurred’’(Stoker1998, 17).We opt for a combined approach to conceptualize governance.We agree with Lynn, Heinrich,and Hill that governance applies to laws and rules that pertain to the provision ofpublic goods.However,we adopt Stoker’s claim that governance is also about collective decision making—and specifically about collective decision making that includes bothpublic and private actors.Collaborative governance is therefore a type of governance inwhich public and private actors work collectively in distinctive ways,using particular processes,to establish laws and rules for the provision of public goods.Although there are many forms of collaboration involving strictly nonstate actors,ourdefinition stipulates a specific role for public agencies.By using the term‘‘public agency,’’our intention is to include public institutions such as bureaucracies,courts,legislatures,andother governmental bodies at the local,state,or federal level.But the typical public in-stitution among our cases is,in fact,an executive branch agency,and therefore,the term‘‘public agency’’is apt.Such public agencies may initiate collaborative forums either tofulfill their own purposes or to comply with a mandate,including court orders,legislation,or rules governing the allocation of federal funds.For example,the Workforce InvestmentAct of1998stipulates that all states and localities receiving federal workforce develop-ment funds must convene a workforce investment board that comprised public and privateactors in order to develop and oversee policies at the state and local level concerning job training,under-and unemployment.According to our definition,these workforce invest-ments boards are mandated to engage in collaborative governance.Although public agencies are typically the initiators or instigators of collaborative governance,our definition requires participation by nonstate stakeholders.Some scholars describe interagency coordination as collaborative governance.Although there is nothing inherently wrong with using the term in this way,much of the literature on collaborativegovernance uses this term to signal a different kind of relationship between public agencies and nonstate stakeholders.Smith (1998,61),for example,argues that collaboratives in-volve ‘‘representation by key interest groups.’’Connick and Innes (2003,180)define collaborative governance as including ‘‘representatives of all relevant interests.’’Reilly (1998,115)describes collaborative efforts as a type of problem solving that involves the ‘‘shared pursuit of government agencies and concerned citizens.’’We use the term ‘‘stakeholder’’to refer both to the participation of citizens as indi-viduals and to the participation of organized groups.For convenience,we will also here-after use the term ‘‘stakeholder’’to refer to both public agencies and nonstate stakeholders,though we believe that public agencies have a distinctive leadership role in collaborative governance.Our definition of collaborative governance also sets standards for the type of participation of nonstate stakeholders.We believe that collaborative governance is never merely consultative.3Collaboration implies two-way communication and influence be-tween agencies and stakeholders and also opportunities for stakeholders to talk with each other.Agencies and stakeholders must meet together in a deliberative and multilateral process.In other words,as described above,the process must be collective .Consultative techniques,such as stakeholder surveys or focus groups,although possibly very useful management tools,are not collaborative in the sense implied here because they do not permit two-way flows of communication or multilateral deliberation.Collaboration also implies that nonstate stakeholders will have real responsibility for policy outcomes.Therefore,we impose the condition that stakeholders must be directly engaged in decision making.This criterion is implicit in much of the collaborative gov-ernance literature.Freeman (1997,22),for example,argues that stakeholders participate ‘‘in all stages of the decisionmaking process.’’The watershed partnerships studied by Leach,Pelkey,and Sabatier (2002,648)make policy and implementation decisions on a range of ongoing water management issues regarding streams,rivers,and watersheds.Ultimate authority may lie with the public agency (as with regulatory negotiation),but stakeholders must directly participate in the decision-making process.Thus,advisory committees may be a form of collaborative governance if their advice is closely linked to decision-making outcomes.In practice (and by design),however,advisory committees are often far removed from actual decision making.We impose the criteria of formal collaboration to distinguish collaborative gover-nance from more casual and conventional forms of agency-interest group interaction.For example,the term collaborative governance might be thought to describe the informal relationships that agencies and interest groups have always cultivated.Surely,interest groups and public agencies have always engaged in two-way flows of influence.The difference between our definition of collaborative governance and conventional interest group influence is that the former implies an explicit and public strategy of organizing this influence.Walter and Petr (2000,495),for example,describe collaborative governance as a formal activity that ‘‘involves joint activities,joint structures and shared resources,’’and Padilla and Daigle (1998,74)prescribe the development of a ‘‘structured arrangement.’’This formal arrangement implies organization and structure.Decisions in collaborative forums are consensus oriented (Connick and Innes 2003;Seidenfeld 2000).Although public agencies may have the ultimate authority to make 3See Beierle and Long (1999)for an example of collaboration as consultation.Journal of Public Administration Research and Theory546Ansell and Gash Collaborative Governance in Theory and Practice547 a decision,the goal of collaboration is typically to achieve some degree of consensus among stakeholders.We use the term consensus oriented because collaborative forumsoften do not succeed in reaching consensus.However,the premise of meeting together ina deliberative,multilateral,and formal forum is to strive toward consensus or,at least,tostrive to discover areas of agreement.Finally,collaborative governance focuses on public policies and issues.The focuson public issues distinguishes collaborative governance from other forms of consensus decision making,such as alternative dispute resolution or transformative mediation. Although agencies may pursue dispute resolution or mediation to reduce social or politicalconflict,these techniques are often used to deal with strictly private conflicts.Moreover,public dispute resolution or mediation may be designed merely to resolve private disputes.While acknowledging the ambiguity of the boundary between public and private,we restrict the use of the term‘‘collaborative governance’’to the governance of public affairs.Our definition of collaborative governance is meant to distinguish collaborative gov-ernance from two alternative patterns of policy making:adversarialism and managerialism (Busenberg1999;Futrell2003;Williams and Matheny1995).By contrast with decisionsmade adversarially,collaborative governance is not a‘‘winner-take-all’’form of interest intermediation.In collaborative governance,stakeholders will often have an adversarial relationship to one another,but the goal is to transform adversarial relationships into more cooperative ones.In adversarial politics,groups may engage in positive-sum bargainingand develop cooperative alliances.However,this cooperation is ad hoc,and adversarial politics does not explicitly seek to transform conflict into cooperation.In managerialism,public agencies make decisions unilaterally or through closed de-cision processes,typically relying on agency experts to make decisions(Futrell2003; Williams and Matheny1995).Although managerial agencies may take account of stake-holder perspectives in their decision making and may even go so far as to consult directlywith stakeholders,collaborative governance requires that stakeholders be directly includedin the decision-making process.A number of synonyms for collaborative governance may cause confusion.For ex-ample,‘‘corporatism’’is certainly a form of collaborative governance as we define it. Classic definitions of corporatism(like Schmitter’s)emphasize tripartite bargaining be-tween peak associations of labor and capital and the state.Typically,these peak associa-tions have a representational monopoly in their sector(they are‘‘encompassing’’).If westart with this narrower definition of corporatism,collaborative governance is the broader term.Collaborative governance often implies the inclusion of a broader range of stake-holders than corporatism,and the stakeholders often lack a representational monopoly overtheir sector.The term‘‘associational governance’’is sometimes used to refer to the more generic mode of governing with associations,but collaborative governance may not even include formal associations.The Porte Alegre project,for example,is a form of collabo-rative governance that includes individual citizens in budgetary decision making(Fung and Wright2001).Sometimes the term‘‘policy network’’is used to describe more pluralistic forms ofstate-society cooperation.A policy network may include both public agencies and stake-holder groups.Moreover,policy networks typically imply cooperative modes of deliber-ation or decision making among actors within the network.Thus,the terms policy networkand collaborative governance can refer to similar phenomena.However,collaborative governance refers to an explicit and formal strategy of incorporating stakeholders intomultilateral and consensus-oriented decision-making processes.By contrast,the co-operation inherent in policy networks may be informal and remain largely implicit (e.g.,unacknowledged,unstated,nondesigned).Moreover,it may operate through infor-mal patterns of brokerage and shuttle diplomacy rather than through formal multilateral processes.Collaborative governance and public-private partnership can also sometimes refer to the same phenomenon.Public-private partnerships typically require collaboration to func-tion,but their goal is often to achieve coordination rather than to achieve decision-making consensus per se.A public-private partnership may simply represent an agreement between public and private actors to deliver certain services or perform certain tasks.Collective decision making is therefore secondary to the definition of public-private partnership.By contrast,the institutionalization of a collective decision-making process is central to the definition of collaborative governance.Finally,a range of terms are often used interchangeably with collaborative gover-nance.Such terms include participatory management,interactive policy making,stake-holder governance,and collaborative management.We prefer the term governance to management because it is broader and encompasses various aspects of the governing process,including planning,policy making,and management.The term collaborative is also more indicative of the deliberative and consensus-oriented approach that we contrast with adversarialism or managerialism than terms like participatory or interactive.A MODEL OF COLLABORATIVE GOVERNANCEArmed with a working definition of collaborative governance,we collected a wide range of case studies from the literature.We did this in the typical fashion:we systematically reviewed journals across a wide range of disciplines,including specialist journals in public health,education,social welfare,international relations,etc.We also conducted key word electronic searches using a wide variety of search terms,including those described above and many more (e.g.,‘‘comanagement,’’‘‘public participation,’’‘‘alternative dispute res-olution’’).Of course,we also followed up on the literature cited in the cases we discovered.Ultimately,our model is built on an analysis of 137cases.Although international in scope,our search was restricted to literature in English,and thus,American cases are overrepre-sented.Even a cursory examination of our cases also suggests that natural resource man-agement cases are overrepresented.This is not due to any sampling bias on our part but rather reflects the importance of collaborative strategies for managing contentious local resource disputes.Most of the studies we reviewed were case studies of an attempt to implement collaborative governance in a particular sector.As you might imagine,the universe of cases we collected was quite diverse and the cases differed in quality,methodology,and intent.Although our definition was restrictive so as to facilitate comparison of apples with apples,representing this diversity was also one of our goals.We perceived experiments with collaborative governance bubbling up in many different policy sectors,with little sense that they were engaged in a similar governance strategy.Surely,we felt,these diverse experiments could learn from each other.Yet this diversity proved a challenge.Our original intention to treat these cases as a large-N data set subject to quasi-experimental statistical evaluation was not successful.Since it is useful for both scholarsJournal of Public Administration Research and Theory548Ansell and Gash Collaborative Governance in Theory and Practice549 and practitioners to understand how we arrived at our conclusions,we briefly report on the problems we encountered in conducting our meta-analysis.Early attempts at systematic coding were frustrating,and we soon developed an understanding of our dilemma.Although scholars studying collaborative governancehad already made some important theoretical statements,the language used to describewhat was happening was far from standardized.We found ourselves groping tofinda common language of description and evaluation even as we were trying to‘‘code’’studies.Add to this challenge a severe problem of‘‘missing data’’—a reflection of thehighly varied motivations of the researchers—and we concluded that a quasi-experimental approach was ill advised.Ultimately,we moved toward a meta-analytic strategy that wecall successive approximation.We selected a subset of our cases and used them to developa common‘‘model’’of collaborative governance.4We then randomly selected additional subsets of case studies.The second subset was used to‘‘test’’the model developed in thefirst round and then to further‘‘refine’’the model.A third sample of cases was used to testthe second-round model,and so on.The appendix provides a list of the studies evaluated ineach of four successive rounds of evaluation.Successive approximation has the advantage of both refining the conceptual modelwhile providing some of the evaluative‘‘discipline’’of a quasi-experimental study.How-ever,we are under no illusion that this process yielded‘‘the one’’model of collaborative governance.There was a large element of art involved in both specifying and evaluatingour model.As we proceeded,we were overwhelmed by the complexity of the collaborative process.Variables and causal relationships proliferated beyond what we felt would ulti-mately be useful for policy makers and practitioners.Therefore,our model representsa conscious attempt to simplify as much as possible the representation of key variablesand their relationships.This goal of simplification led us to stress common and frequentfindings across cases.This approach strengthens the generality of ourfindings but dis-counts less universal or frequently mentionedfindings from the literature.Toward the endof our analysis,we were ourselves in disagreement about how to represent key relations.We used thefinal round of case analysis to settle these differences.One other important clarification needs to be made before we introduce ourfindings.Our survey of the cases quickly disabused us of the notion that we could use our analysis to answer the question:‘‘Is collaborative governance more effective than adversarial or managerial governance?’’Very few of the studies we reviewed actually evaluated gover-nance outcomes.This is not to say that the comparison between collaborative,adversarial,and managerial governance is not relevant to these studies.Experiments with collaborative governance were typically driven by earlier failures with adversarial or managerial approaches.But systematic comparisons were rarely explicitly made.What most studiesdid try to do was understand the conditions under which stakeholders acted collaboratively.Did they engage in good faith negotiation?Did they pursue mutual gains?Did they achieve consensus?Were they satisfied with the process?In other words,most studies in the collaborative governance literature evaluate‘‘process outcomes’’rather than policy or management outcomes.Figure1provides a visual representation of our centralfindings.The model has fourbroad variables—starting conditions,institutional design,leadership,and collaborative4To avoid recreating the wheel,ourfirst subset was not randomly selected but included many of the most prominent theoretical statements about collaborative governance.process.Each of these broad variables can be disaggregated into more fine-grained vari-ables.Collaborative process variables are treated as the core of our model,with starting conditions,institutional design,and leadership variables represented as either critical contributions to or context for the collaborative process.Starting conditions set the basic level of trust,conflict,and social capital that become resources or liabilities during col-laboration.Institutional design sets the basic ground rules under which collaboration takes place.And,leadership provides essential mediation and facilitation for the collaborative process.The collaborative process itself is highly iterative and nonlinear,and thus,we represent it (with considerable simplification)as a cycle.The remainder of the article describes each of these variables in more detail and draws out their implications for a contingency model of collaborative governance.STARTING CONDITIONSThe literature is clear that conditions present at the outset of collaboration can either facilitate or discourage cooperation among stakeholders and between agencies and stake-holders.Imagine two very different starting points.In one,the stakeholders have a history of bitter division over some emotionally charged local issue and have come to regard each other as unscrupulous enemies.In the other,the stakeholders have a shared vision for what they would like to achieve through collaboration and a history of past cooperation and mutual respect.In both cases,collaboration may be difficult,but the first case must over-come problems of distrust,disrespect,and outright antagonism.We narrowed the critical starting conditions down to three broad variables:imbalances between the resources orFigure 1A Model of Collaborative GovernanceJournal of Public Administration Research and Theory550。
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A review of the species of protozoan epibionts on crustaceans-11
A REVIEW OF THE SPECIES OF PROTOZOAN EPIBIONTS ONCRUSTACEANS.I.PERITRICH CILIATESBYGREGORIO FERNANDEZ-LEBORANS and MARIA LUISA TATO-PORTODepartamento de Biologia Animal I(Zoologia),Facultad de Biologia,Pnta9a,Universidad Complutense,E-28040Madrid,SpainABSTRACTAn updated inventory of the peritrich(Protozoa,Ciliophora)epibiont species on crustaceans has been carried out.Data concerning268epibiont species,their taxonomic position,and the various crustacean basibionts were considered.The overview comprised in this study may be of use in further surveys of protozoan-crustacean epibiosis.RESUMENSe ha realizado un inventario actualizado de las especies de peritricos(Protozoa,Ciliophora) epibiontes en crustáceos.Se han considerado los datos concernientes a268especies epibiontes,su posición taxonómica,y los diferentes crustáceos visión general que comprende este estudio puede ser utilizada en futuras investigaciones sobre la epibiosis protozoos-crustáceos.INTRODUCTIONEpibiosis is a facultative association of two organisms:the epibiont and the basibiont(Wahl,1989).The term“epibiont”includes organisms that,during the sessile phase of their life cycle,are attached to the surface of a living substratum, while the basibiont lodges and constitutes a support for the epibiont(Threlkeld et al.,1993).Both concepts describe ecological functions(Wahl,1989).Several crustacean groups,cladocerans,copepods,cirripedes,isopods,amphi-pods,and decapods,include forms that are hosts for macroepibiont invertebrates (Ross,1983),and for protozoan microepibionts of the phylum Ciliophora:apos-tomatids,chonotrichids,suctorians,peritrichs,and heterotrichs(Corliss,1979; Small&Lynn,1985).The study of ciliate epibionts on crustaceans began in the last century.Bütschli(1887-89)made a compilation from former publications.After-wards,other authors(Keiser,1921;Kahl,1934,1935;Precht,1935;Raabe,1947; c®Koninklijke Brill NV,Leiden,2000Crustaceana73(6):643-683644G.FERNANDEZ-LEBORANS&M.L.TATO-PORTONenninger,1948)not only described epibiont species,but proposed explanations for the processes of epibiosis.A review of the protozoan epibionts found on de-capod crustaceans was carried out by Sprague&Couch(1971).Green(1974), in a study of the epibionts living on cladocerans,pays considerable attention to protozoan species.Ho&Perkins(1985)have focused on the epibionts found on copepods.In other contemporary and also earlier works,the following aspects have been taken into account:(1)speci city between ciliates and their crustacean basi-bionts(Evans et al.,1981;Batisse,1986,1992;Clamp,1991);(2)the morpholog-ical and physiological adaptations of the epibionts(D’Eliscu,1975;Batisse,1986, 1994;Fenchel,1987;Clamp,1991;Lom&De Puytorac,1994);(3)the effects pro-duced by the epibionts on the crustaceans(Herman et al.,1971;Turner et al.,1979; Kankaala&Eloranta,1987;Nagasawa,1988);(4)the possible use of epibionts for the assessment of water quality(Antipa,1977;Henebry&Ridgeway,1979;Scott &Thune,1986);(5)the implications of protozoan epibionts on cultures of vari-ous species of crustaceans(Overstreet,1973;Johnson,1977,1978;Lightner,1977, 1988;Couch,1978;Scott&Thune,1986;V ogelbein&Thune,1988;Camacho& Chinchilla,1989);and(6)the organization of the epibiont communities on plank-tonic crustaceans(Threlkeld et al.,1993).Despite the fact that there is a considerable amount of information about the protozoan epibionts on crustaceans,since the works of Sprague&Couch(1971), Green(1974),and Ho&Perkins(1985),which relate to speci c crustacean groups, no further general reviews have appeared.Several new species of protozoan ciliate epibionts have recently been described(Dovgal,1985;Batisse,1992;Fernandez-Leborans&Gomez del Arco,1996;Zhadan&Mikrjukov,1996;Fernandez-Leborans et al.,1996,1997),and some of these are peritrich ciliates(Matthes& Guhl,1973;Bierhof&Roos,1977;Jankowski,1986;Dale&Blom,1987;Clamp, 1990,1991;Threlkeld&Willey,1993;Hudson&Lester,1994;Stoukal&Matis, 1994;Foissner,1996).The purpose of this work is to provide an up-to-date review of the peritrich ciliates living as epibionts on crustaceans:268species have been considered in this compilation,which may contribute data for studies of epibiosis in crustaceans.CRUSTACEAN PROTOZOAN EPIBIONTS,I.PERITRICH CILIATES645RESULTS1)Phylum CILIOPHORA Do ein,1901Class OLIGOHYMENOPHOREA De Puytorac,Batisse,Bohatier,Corliss, Deroux,Didier,Dragesco,Fryd-Versavel,Grain,Grolière,Hovasse,Iftode,Laval,Roque,Savoie&Tuffrau,1974Subclass P ERITRICHIA Calkins,1933Order S ESSILIDA Kahl,1933Family Epistylididae Kahl,1935Genus Rhabdostyla Kent,1880( g.1)R.bosminae Levander,1907.On the cladoceran Bosmina sp.R.conipes Kahl,1935.On the cladoceran Daphnia sp.Fresh water.On the cladocerans Daphnia magna,D.longispina and Scapholeberis mucronata (cf.Green,1957,1974).R.cyclopis Kahl,1935.On the copepod Cyclops sp.Fresh water.R.cylindrica Stiller,1935.On the cladoceran Leptodora ke Balaton (Hungary).On the cladoceran Leptodora kindtii.Denmark(Green,1974).R.hungarica Stiller,1931.On the cladoceran Leptodora ke Balaton (Hungary).R.globularis Stokes,1890.On the cladoceran Bosmina longirostris and on Diaphanosoma brachyurum.Germany(Nenninger,1948).R.invaginata Stokes,1886.On the ostracod Cypris sp.R.sessilis Penard,1922.On the copepod Cyclops sp.Fresh water.R.pyriformis Perty,1852(cf.Kahl,1935;on Entomostraca).On the clado-ceran Daphnia longispina(cf.Nenninger,1948).On the cladoceran Daph-nia hyalina(cf.Sommer,1950).On Daphnia pulex and Ceriodaphnia reticu-lata(cf.Hamman,1952).On Daphnia magna,D.pulex,D.cucullata,Simo-cephalus vetulus,Ceriodaphnia reticulata,and Leptodora kindtii(cf.Green, 1953).On Daphnia magna(cf.Green,1955).On Daphnia magna andD.longispina(cf.Green,1957).On Daphnia atkinsoni,D.hyalina,D.lon-gispina,D.curvirostris,D.obtusa,Ceriodaphnia laticaudata,and C.pulchel-la(cf.Green,1974).R.vernalis Stokes,1887.On the copepod Eucyclops agilis(cf.Henebry& Ridgeway,1979).1)For authors and dates of species of Crustacea mentioned herein,see separate section,below.646G.FERNANDEZ-LEBORANS&M.L.TATO-PORTOFigs.1-2.1,Rhabdostyla(R.pyriformis,after Green,1957);2,Epistylis(E.gammari,after Precht,1935).Rhabdostyla sp.Bierhof&Roos,1977.Between the spines at the end of the telson on Gammarus tigrinus.Germany.Rhabdostyla sp.Weissman et al.,1993.On the copepod Acartia hudsonica. Genus Epistylis Ehrenberg,1832( g.2)E.anastatica(Linnaeus,1767)(cf.Kent,1881).Syn.:Vorticella anastatica L.,1767.On Entomostraca and freshwater plants.On cyclopoid copepods and Daphnia pulex(cf.Green,1974).E.astaci Nenninger,1948.Fresh water.On the gills of the decapod Astacusastacus(as A. uviatilis)(Germany).On A.leptodactylus(cf.Stiller,1971).On the gills of Austropotamobius torrentium(cf.Matthes&Guhl,1973).E.bimarginata Nenninger,1948.Fresh water.On the appendages of Astacusastacus(as A. uviatilis).Germany.E.branchiophila Perty,1852.Syn.:E.formosa Nenninger,1948.On theparasitic copepod Lernaea cyprinacea,in freshwater environments of South Africa(Van As&Viljoen,1984).E.breviramosa Stiller,1931.On the antennal lament of the cladoceran Daph-nia ke Balaton(Hungary).On the copepod Cyclops sp.,Czechoslovakia (Srámek-Husek,1948).On the cladocerans Bosmina longirostris and Alona af nis(cf.Green,1974).E.cambari Kellicott,1885.On the gills of the decapod Cambarus sp.(NE ofU.S.A.).On the maxillae of the cray sh Astacus leptodactylus(fresh water) (cf.Matthes&Guhl,1973).E.crassicollis Stein,1867.On freshwater Entomostraca and on the pleopodsand gills of cray sh.On the gills of Astacus astacus(as A. uviatilis),andCRUSTACEAN PROTOZOAN EPIBIONTS,I.PERITRICH CILIATES647 the maxillae,maxillipeds,and gills of A.leptodactylus,in Europe(Matthes& Guhl,1973).E.cyprinaceae Van As&Viljoen,1984.On the parasitic copepod Lernaea cyprinacea(fresh water,South Africa).E.daphniae Fauré-Fremiet,1905.On the cladoceran Daphnia sp.On Daphnia magna(cf.Nenninger,1948).On the copepod Boeckella triarticulata(New Zealand)(Xu&Burns,1990).On the cladoceran Moina macrocopa in an urban stream.E.diaptomi Fauré-Fremiet,1905.On the copepod Diaptomus sp.E.digitalis Ehrenberg,1838.On the copepod Cyclops sp.E.epibarnimiana Van As&Viljoen,1984.On the parasitic copepod Lernaea barnimiana(fresh water,South Africa).E.fugitans Kellicott,1887.On the cladoceran Sida crystallina.North America.E.gammari Precht,1935.On the antennae of the gammarid Gammarus sp. (Kiel channel).On the proximal part of the rst antenna and,less commonly, on the second antenna of Gammarus oceanicus and G.salinus.In the Baltic Sea and areas of Norway(Fenchel,1965).On the rst antenna of Gammarus tigrinus(cf.Stiller,1971).E.halophila Stiller,1942.On the cladocerans Daphnia longispina and D.pulex (Lake Cserepeser,Hungary).E.harpacticola Kahl,1933.On harpacticoid copepods in the Kiel channel. E.helenae Green,1957.On the cladocerans Daphnia pulex,D.magna,D.ob-tusa,D.longispina,D.curvirostris,Ceriodaphnia pulchella,C.reticulata, ticaudata,Moina macrocopa,M.micrura,Chydorus sphaericus,Simo-cephalus serrulatus,and S.vetulus(cf.Green,1957,1974).On Daphnia magna(cf.Nenninger,1948).On Ceriodaphnia reticulata and Simocephalus vetulus(cf.Matthes,1950).E.humilis Kellicott,1887.On the gammarid Gammarus sp.and other Ento-mostraca.custris Imhoff,1884.On the pelagic copepod Cyclops sp.On the buccal appendages of the branchiopod Lepidurus apus(freshwater areas near Vienna, Austria)(Foissner,1996).E.magna V an As&Viljoen,1984.On the parasitic copepod Lernaea cypri-nacea(fresh water,South Africa).E.niagarae Kellicott,1883.On the body surface of cray sh(Niagara River, U.S.A.).On the antennae and body of the European cray sh Astacus lep-todactylus,on Austropotamobius torrentium,and on Orconectes limosus(as Cambarus af nis)(cf.Matthes&Guhl,1973).On the surface of the copepod648G.FERNANDEZ-LEBORANS&M.L.TATO-PORTOEucyclops serrulatus,and on the cladocerans Daphnia pulex,D.rosea,Cerio-daphnia reticulata,and Scapholeberis mucronata(lakes of Colorado,U.S.A.) (Willey&Threlkeld,1993).E.nitocrae Precht,1935.On the third pereiopod of Gammarus tigrinus(cf.Bierhof&Roos,1977).E.nympharum Engelman,1862.On cladocerans(Nenninger,1948).On Cy-clops sp.(cf.Foissner&Schiffman,1974).On the branchiuran Dolops ra-narum(cf.Van As&Viljoen,1984).E.ovalis Biegel,1954.On the gnathopods of Gammarus tigrinus.On the thirdpereiopod of the gammarid Gammarus pulex,and on the spines at the end of the third uropod of Gammarus tigrinus(cf.Bierhof&Roos,1977).E.plicatilis Ehrenberg,1838.On the copepods Eucyclops agilis,Cyclopsvernalis,and C.bicuspidatus(Ashmore Lake,Illinois,U.S.A.)(Henebry& Ridgeway,1979).E.salina Stiller,1941.On the rst and second antennae,coxae,and gills of thegammarid Gammarus pulex(cf.Bierhof&Roos,1977).E.thienemanni Sommer,1951.On the gills of Gammarus tigrinus(cf.Bierhof&Roos,1977).E.zschokkei(Keiser,1921).Syn.:Opercularia zschokkei Keiser,1921.On thegnathopods of the gammarid Gammarus tigrinus and on other Entomostraca.On the cladoceran Acantholeberis curvirostris(cf.Nenninger,1948).Epistylis sp.Hutton,1964.On the decapod Penaeus duorarum(Florida,U.S.A.).Between the setae of the rst antenna of Gammarus tigrinus(cf.Bierhof& Roos,1977).Epistylis sp.Hutton,1964.On the decapod Ploeticus robustus(Daytona Beach, Florida,U.S.A.).Epistylis sp.Viljoen&Van As,1983.Two species on the thoracic appendages of a freshwater brachyuran,apparently erroneously identi ed as“Potamon sp.”(South Africa)[the genus Potamon does not occur in southern Africa].Epistylis sp.Pearse,1932.On the gills of the decapods Coenobita clypeatus, Geograpsus lividus,and Pachygrapsus transversus(Florida,U.S.A.).Epistylis sp.Hudson&Lester,1994.On the gills of the decapod Scylla serrata (Moreton Bay,Queensland,Australia).Epistylis sp.Turner et al.,1979.On the estuarine copepods Acartia tonsa andA.clausi(Escambia Bay,Florida,U.S.A.).Epistylis sp.Villarreal&Hutchings,1986.Fresh water.On the maxillipeds, pereiopods,and ventral portion of the abdomen of the decapod Cherax tenuimanus(Australia).CRUSTACEAN PROTOZOAN EPIBIONTS,I.PERITRICH CILIATES649 Family Lagenophryidae Bütschli,1889Genus Lagenophrys Stein,1852( g.3)L.aegleae Mouchet-Bennati,1932.Fresh water.On the branchial laments of the anomurans Aegla sp.,Aegla castro,and Aegla franca.Arroyo Miguelete, (Uruguay)and Parana River(Brazil).L.ampulla Stein,1851.Fresh water.On the gills of species of the genus Gammarus.L.andos(Jankowski,1986)(cf.Clamp,1991).Syn.:Circolagenophrys andos Jankowski,1986.Fresh water.On the decapod Parastacus chilensis(Chile).L.anticthos Clamp,1988.Fresh water.On the branchial laments of the decapods Parastacus pugnax,P.defossus,and P.saffordi(Chile,Brazil, Uruguay).L.aselli Plate,1886.On the branchial surface of the isopod Asellus aquaticus (Hamburg,Germany).L.awerinzewi Abonyi,1928.On the gills of the decapod Potamon uviatilis(as Telphusa uviatilis)(Africa).L.bipartita Stokes,1890.On the cladoceran Daphnia sp.(fresh water,U.S.A.).L.branchiarum Nie&Ho,1943.Fresh water.On the gills of the caridean shrimp Macrobrachium nipponense(as Palaemon nipponense)(Japan).L.callinectes Couch,1967.Marine and in estuaries.On the gills of the decapods Callinectes sapidus,C.bocourti,and C.maracaiboensis(Chesapeake Bay, Maryland,Virginia,and Gulf of Mexico).mensalis Swarczewsky,1930.Fresh water.On gammarids(Lake Baikal).L.darwini Kane,1965.On the branchial laments of the decapod Cherax quadricarinatus(stream near Darwin,Australia).L.dennisi Clamp,1987.Fresh water.On the decapods Orconectes illinoiensis, Cambarus bartonii bartonii,and C.chasmodactylus(North America).L.deserti Kane,1965.Fresh water.On the gills of the decapods Cherax tenuimanus and C.quinquecarinatus(SW rivers,Australia).L.diogenes(Jankowski,1986).Syns.:Circolagenophrys diogenes Jankowski, 1986,Lagenophrys incompta Clamp,1987.Fresh water.On the gills of the decapods Orconectes illinoiensis and Cambarus diogenes(Illinois,U.S.A.).L.discoidea Kellicott,1887(cf.Clamp,1990).Syns.:Lagenophrys labiata Wallengren,1900(a junior homonym of biata Stokes,1887(cf.Clamp, 1990));L.wallengreni Abonyi,1928;Circolagenophrys entocytheris Jankow-ski,1986.Fresh water.On ostracods.On the cray sh Cambarus sp.,C.chas-modactylus,C.bartonii bartonii,and Orconectes illinoiensis(Ontario,Canada and U.S.A.).650G.FERNANDEZ-LEBORANS&M.L.TATO-PORTOFigs.3-7.3,Lagenophrys(L.eupagurus,after Clamp,1989);4,Clistolagenophrys(C.primitiva, after Swarczewsky,1930);5,Setonophrys(munis,after Clamp,1991);6,Operculigera (O.asymmetrica,after Clamp,1991);7,Usconophrys(U.aperta,after Clamp,1991).L.dungogi Kane,1965.On the branchial laments of the decapod Euastacus sp.(stream near Dungog,Australia).L.engaei Kane,1965.On the branchial laments,basal areas of the gills, branchiostegite membrane and,more rarely,on the pleopods of the decapods Engaeus victoriensis and Austroastacus hemicirratulus(Victoria,Tasmania, and Melbourne,Australia).L.eupagurus Kellicott,1893(cf.Clamp,1989).Syns.:Lagenophrys lunatus Imamura,1940;Lagenophrys articularis Nie&Ho,1943.Marine,in estu-arine areas and fresh water.On the decapods Litopenaeus setiferus(as Pe-CRUSTACEAN PROTOZOAN EPIBIONTS,I.PERITRICH CILIATES651 naeus s.)(Penaeidea,Penaeidae),on the surface of the body,Litopenaeus van-namei(as Penaeus v.),on the surface of the body,Macrobrachium nipponense (Caridea,Palaemonidae)on antennae and pleopods,Macrobrachium ohione, on the surface of the middle of the pleura,Macrobrachium rosenbergii,on the gills,Palaemon paucidens(Caridea,Palaemonidae),Palaemonetes inter-medius(Caridea,Palaemonidae),Palaemonetes kadiakensis,Palaemonetes paludosus,Palaemonetes pugio,Palaemonetes varians,on the whole body, except on the gills,Palaemonetes vulgaris,Upogebia af nis(Thalassinidea, Upogebiidae),and Pagurus longicarpus(Anomura,Paguridae),on the gills (U.S.A.,Japan,Venezuela,Thailand).L.foxi Clamp,1987.Fresh water.On the gills of the gammarids Gammarus pseudolimnaeus,G.troglophilus,G.minus,and Gammarus sp.(Missouri, U.S.A.).L.in ata Swarczewsky,1930.On the distal areas of pleopods of the gammarid Gmelinoides fasciata(Lake Baikal).L.jacobi(Kane,1969).Syn.:Stylohedra jacobi Kane,1969.On freshwater decapods in Australia.L.johnsoni Clamp,1990.Syn.:Lagenophrys labiata Stokes,1887(partim). Fresh water.On the appendages and the surface of the carapace of the gammarids Gammarus fasciatus,G.daiberi,G.tigrinus,and Crangonyx gracilis(New Jersey,Michigan,and North Carolina,U.S.A.).biata Stokes,1887(cf.Clamp,1990).Fresh water.On the appendages and on the surface of the carapace of the gammarids Gammarus fasciatus, G.daiberi,G.tigrinus,and Cangronyx gracilis(New Jersey,Michigan,and North Carolina,U.S.A.).L.leniusculus(Jankowski,1986).Syns.:Circolagenophrys leniusculus Jan-kowski,1986;L.oregonensis Clamp,1987.Fresh water.On the carapace, gills,ventral surface of the abdomen,uropods,pereiopods,and pleopods of the decapod Pacifastacus leniusculus leniusculus,and on the gills of P.leniusculus trowbridgii and P.connectens(North America).L.lenticula(Kellicott,1885)(cf.Clamp,1991).Syns.:Stylohedra lenticula Kellicott,1885;S.lenticulata Kahl,1935;Lagenophrys lenticulata(Kahl, 1935)(cf.Thomsen,1945).Fresh water.Setae of the sixth and seventh pereiopods of the gammarids Hyalella azteca and H.curvispina(U.S.A., Canada,Mexico,and Uruguay).L.limnoria Clamp,1988.Syn.:Circolagenophrys circularis Jankowski,1986 (cf.Clamp,1991).On the isopod Limnoria lignorum.L.macrostoma Swarczewsky,1930.Fresh water.On gammarids(Lake Baikal). L.matthesi Schödel,1983.On the maxillipeds of the gammarids Gammarus pulex and Carinogammarus roeselii.652G.FERNANDEZ-LEBORANS&M.L.TATO-PORTOL.metopauliadis Corliss&Brough,1965.Fresh water.On the gills of the brachyuran Metopaulias depressus(endemic on Jamaica).L.monolistrae Stammer,1935.On the pleopods of the isopod Monolistra sp.L.nassa Stein,1852.Fresh water.On the pleopods of the gammarid Gammarus pulex.L.oblonga Swarczewsky,1930.On the antennae of the gammarid Gammarus hyacinthinus(Lake Baikal).L.orchestiae Abonyi,1928.On the amphipod Orchestia cavimana(Lake Balaton,Hungary).L.ornata Swarczewsky,1930.Fresh water.On ke Baikal.L.ovalis Swarczewsky,1930.Fresh water.On the thoracic appendages of ke Baikal.L.parva Swarczewsky,1930.On ke Baikal.L.patina Stokes,1887(cf.Clamp,1990).Syn.:Lagenophrys labiata Stokes, 1887(cf.Shomay,1955).(Corliss&Brough,1965;Clamp,1973).Fresh water.On the pereiopods and gills of the gammarids Gammarus sp.and Hyalella azteca.American continent.L.rugosa Kane,1965.Fresh water.On the gills of the decapod Geocharax falcata(Victoria,Australia).L.similis Swarczewsky,1930.On ke Baikal.L.simplex Swarczewsky,1930.On ke Baikal.L.solida Swarczewsky,1930.On ke Baikal.L.stammeri Lust,1950.On ostracods.Germany.(Lust,1950a).L.stokesi Swarczewsky,1930.On ke Baikal.L.stygia Clamp,1990.Syn.:Lagenophrys labiata Stokes,1887(cf.Jakschik, 1967).Subterranean water.On the gills of the cave-dwelling amphipod Bactrurus mucronatus(Illinois,U.S.A.).L.tattersalli Willis,1942.On European copepods.L.turneri Kane,1969.On freshwater decapods in Australia.L.vaginicola Stein,1852.Syn.:Lagenophrys obovata Stokes,1887.On the genital setae and thoracopods of the copepods Cyclops miniatus and Cantho-camptus sp.L.verecunda Felgenhauer,1982.On the decapod Palaemonetes kadiakensis (Illinois,U.S.A.).L.willisi Kane,1965.Fresh water.On the gills of the decapods Cherax destructor,C.albidus,and C.rotundus(Melbourne,New South Wales(e.g., Newcastle),and NW Australia).Genus Clistolagenophrys Clamp,1991( g.4)C.primitiva(Swarczewsky,1930)(cf.Clamp,1991).Syn.:Lagenophrys primi-tiva Swarczewsky,1930.On pereiopods and pleopods of the gammarid Pallasea cancellus(Lake Baikal).Genus Setonophrys Jankowski,1986(cf.Clamp,1991)( g.5)S.bispinosa(Kane,1965)(cf.Clamp,1991).Syn.:Lagenophrys bispinosa Kane,1965.On pereiopods of the decapod Cherax rotundus setosus.Stream near Newcastle(N.S.W.,Australia).munis(Kane,1965)(cf.Clamp,1991).Syn.:Lagenophrys communis Kane,1965.On the body surface(telson,pleopods,pereiopods,carapace...) of the decapod Cherax destructor.On the gills of the decapods C.rotundus,C.albidus,C.quadricarinatus,Euastacus armatus,and Engaeus marmoratus(Victoria,Melbourne,and Tasmania,Australia).S.lingulata(Kane,1965)(cf.Clamp,1991).Syn.:Lagenophrys lingulata Kane,1965.On the branchial laments and branchiostegite membrane of the decapods Cherax destructor, C.albidus,and C.rotundus(Victoria, Melbourne,and coastal and central areas of Australia).S.nivalis(Kane,1969)(cf.Clamp,1991).Syn.:Lagenophrys nivalis Kane, 1969.On freshwater decapods in Australia.S.occlusa(Kane,1965)(cf.Clamp,1991).Syn.:Lagenophrys occlusa Kane, 1965.On the anterior zone of the branchial cavity of the decapods Cherax destructor,C.albidus,and C.rotundus(Victoria and New South Wales, Australia).S.seticola(Kane,1965)(cf.Clamp,1991).Syn.:Lagenophrys seticola Kane, 1965.On the setae of the decapods Engaeus fultoni and Geocharax falcata (Victoria,Melbourne,and Templestowe,Australia).S.spinosa(Kane,1965)(cf.Clamp,1991).Syn.:Lagenophrys spinosa Kane, 1965.On the pleopods,carapace,and telson of the decapod Cherax destructor (Victoria,Melbourne,and Heathcote,Australia).S.tricorniculata Clamp,1991.On the pleopods of the decapod Geocharax falcata(Victoria,Grampian Mountains,and Wannon River,Australia). Genus Operculigera Kane,1969( g.6)O.asymmetrica Clamp,1991.On the base of the gills of the freshwater decapods Parastacus pugnax and Samastacus spinifrons(Concepción and Talcahuano,Chile).O.insolita Clamp,1991.On the base of the gills of the freshwater decapod Parastacus pugnax(Concepción,Talcahuano,Malleco,and Puren,Chile).O.montanea Kane,1969.On the freshwater decapod Colubotelson sp.(Aus-tralia).O.obstipa Clamp,1991.Pleopods of the isopod Metaphreatoicus australis (New South Wales,Australia).O.parastacis Jankowski,1986.On the base of the gills of the decapod Parastacus nicoleti(Isla Teja,Valdivia,Chile).O.seticola Clamp,1991.On the setae at the base of gills of the decapod Parastacus pugnax(Concepción,Chile).O.striata Jankowski,1986.On the decapod Parastacus chilensis.Chile.O.taura Clamp,1991.On the branchial laments of the freshwater decapod Parastacus pugnax(Concepción,Malleco,and Puren,Chile).O.velata Jankowski,1986.On the gills of the anomuran Aegla laevis.Chile.O.zeenahensis Kane,1969.On freshwater decapods in Australia.Family Usconophryidae Clamp,1991Genus Usconophrys Jankowski,1985(cf.Clamp,1991)( g.7)U.aperta(Plate,1889)(cf.Clamp,1991).Syns.:Lagenophrys aperta Plate, 1889;Usconophrys dauricus Jankowski,1986.On the gills and pleopods of the isopod Asellus aquaticus(Marburg and Hessen,Germany;North Carolina, U.S.A.;Brittany,Finisterre,Plougarneau,Pont-Menou,and Douron River, France).U.rotunda(Precht,1935)(cf.Clamp,1991).Syn.:Lagenophrys rotunda Precht,1935.On ostracods.Germany.Family Operculariidae Fauré-Fremiet,1979(in Corliss,1979)Genus Opercularia Stein,1854( g.8)O.allensi Stokes,1887.Syn.:O.ramosa Stokes,1887.On several living and inert substrata.On the body of the cray sh Astacus leptodactylus(cf.Matthes &Guhl,1973).O.asellicola Kahl,1935.On the isopod Asellus sp.Germany.O.coarctata Claparède&Lachmann,1858.On crabs(Buck,1961).O.crustaceorum Biegel,1954.On the gills of the cray sh Astacus astacus(asA. uviatilis).On the maxillae,maxillipeds,and pleopods of Austropotamo-bius torrentium(cf.Matthes&Guhl,1973).O.cylindrata Wrzesniowski,1807.On the copepod Cyclops sp.O.gammari Fauré-Fremiet,1905.Pereiopods of the gammarid amphipod Gammarus sp.O.lichtensteini Stein,1868.On various crabs and molluscs.O.nutans Ehrenberg,1838.Syn.:O.microstoma Stein,1854.On Entomostraca.On the cladoceran Alona af nis(cf.Matthes,1950).On the maxillipeds of the European cray sh Astacus leptodactylus(cf.Matthes&Guhl,1973).O.protecta Penard,1922.On the setae of pereiopods of the gammarid amphi-pod Gammarus pulex.O.reichelei Matthes&Guhl,1973.Found exclusively on the maxillipeds of the cray sh Astacus leptodactylus.O.stenostoma Stein,1868.On the isopod Asellus aquaticus.Genus Orbopercularia Lust,1950(cf.Lust,1950b)( g.9)O.astacicola(Matthes,1950)(cf.Matthes&Guhl,1973).Syn.:Opercularia astacicola Matthes,1950.Maxillipeds and pleopods of the cray sh Aus-tropotamobius torrentium.Genus Propyxidium Corliss,1979( g.10)P.aselli Penard,1922.On the isopod Asellus sp.P.asymmetrica Matthes&Guhl,1973.On the European cray sh Astacus astacus(as A. uviatilis).P.bosminae Kahl,1935.On the cladoceran Bosmina sp.P.canthocampti Penard,1922.On the pereiopods of the harpacticoid copepod Canthocamptus sp.Fresh water.P.cothurnioide Kent,1880.On the ostracod Cypris sp.P.hebes Kellicott,1888.On the pereiopods of the isopod Asellus aquaticus.P.henneguyi(Fauré-Fremiet,1905)(cf.Kahl,1935).Syn.:Opercularia hen-neguyi Fauré-Fremiet,1905.On the rst abdominal segment of the copepod Cyclops sp.Genus Ballodora Dogiel&Furssenko,1921( g.11)B.dimorpha Dogiel&Furssenko,1921.On Porcellio sp.and other terrestrialisopods.Genus Nuechterleinella Matthes,1990( g.12)N.corneliae Matthes,1990.On the ostracod Cypria ophthalmica.Genus Bezedniella Stoukal&Matis,1994( g.13)B.prima Stoukal&Matis,1994.Fresh water.On the ostracod Cypria sp.(Slovakia).Figs.8-14.8,Opercularia(O.nutans,after Foissner et al.,1992);9,Orbopercularia(O.astacicola, after Matthes&Guhl,1973);10,Propyxidium(P.canthocampti,after Penard,1922);11,Ballodora (B.dimorpha,after Dogiel&Furssenko,1921);12,Nuechterleinella(N.corneliae,after Matthes, 1990);13,Bezedniella(B.prima,after Stoukal&Matis,1994);14,Rovinjella(R.spheromae,afterMatthes,1972).Family Rovinjellidae Matthes,1972Genus Rovinjella Matthes,1972( g.14)R.spheromae Matthes,1972.On the marine isopod Sphaeroma serratum. Family Scyphidiidae Kahl,1933Genus Scyphidia Dujardin,1841( g.15)Scyphidia sp.Henebry&Ridgeway,1979.On the cladocerans Scapholeberis kingi,Alona costata,and Pleuroxus denticulatus(Ashmore Lake,Illinois, U.S.A.).Family Vaginicolidae De Fromentel,1874Genus Platycola Kent,1881( g.16)P.baikalica(Swarczewsky,1930).Syn.:Vaginicola baicalica Swarczewsky, 1930.Fresh water.On the gills of the gammarids Brandtia lata,Pallasea grubei,and Echinogammarus fuscus(Lake Baikal).P.callistoma Hadzi,1940.Fresh water.On the cave-dwelling isopod Microlis-tra spinosissima(former Yugoslavia).P.circularis Dons,1940.Marine.On the uropods of the isopod Limnoria sp.P.decumbens(Ehrenberg,1830).Syns.:Vaginicola decumbens Ehrenberg, 1830;Platycola ampulla De Fromentel,1874;P.regularis De Fromentel, 1874;P.striata De Fromentel,1874;P.truncata De Fromentel,1874;P.longicollis Kent,1882;P.intermedia Kahl,1935;P.re exa Kahl,1935;P.amphora Swarcezwsky,1930;P.amphoroides Sommer,1951.Fresh water.On several vegetable and animal substrata.On the gills of the gammarid Brachiuropus sp.(Lake Baikal)(Swarczewsky,1930).geniformis Hadzi,1940.Fresh water.On the cave-dwelling isopod Micro-listra spinosissima(former Yugoslavia).P.pala Swarczewsky,1930.Syn.:Vaginicola pala Swarczewsky,1930.On the gills of the gammarid Palicarinus puzyllii(as Parapallesa pazill)(Lake Baikal).Genus Cothurnia Ehrenberg,1831(cf.Claparède&Lachmann,1858)( g.17)C.angusta Kahl,1933.Brackish or fresh water.On ostracods(Kiel,Germany).C.anomala Stiller,1951.Fresh water.On the amphipod Corophium curvispi-num(Lake Balaton,Hungary).C.antarctica(Daday,1911)(cf.Warren&Paynter,1991).Syn.:Cothurniopsisantarctica Daday,1911.Marine.Epibiont on the ostracod Philomedes lae-vipes(Antarctic areas).C.astaci Stein,1854.Fresh water.On the pleopods and gills of cray sh.On the maxillae,maxillipeds,and pleopods of the cray sh Astacus astacus。
全身运动不安运动阶段质量评估对婴幼儿神经系统疾病预测价值的Meta分析
全身运动不安运动阶段质量评估对婴幼儿神经系统疾病预测价值的Meta分析门光国;王凤敏;崔英波【摘要】目的探讨婴幼儿早期(出生后20周内)全身运动(GMs)不安运动阶段质量评估对婴幼儿神经系统疾病的预测价值.方法利用数据库检索到2015年12月前发表的相关文献,共有16篇文献纳入研究并进行Meta分析.结果 16篇文献QUADAS评分≥10的有8篇,临床特征等信息差异均无统计学意义(P＞0.05).GMs 不安运动阶段质量评估对神经系统发育不良结局(包括脑性瘫痪)的预测分析显示,灵敏度、特异度、阳性似然比(PLR)、阴性似然比(NLR)和诊断比值比(DOR)分别为0.78、0.93、11.26、0.24和55.43;SROC曲线表明灵敏度和特异度最佳结合点的Q值为0.852 2,AUC值为0.919 0.GMs不安运动阶段质量评估对脑性瘫痪的预测分析显示,灵敏度、特异度、PLR、NLR和DOR分别为0.91、0.94、12.91、0.12和133.66,SROC曲线表明灵敏度和特异度最佳结合点的Q值为0.918 5,AUC值为0.969 2.结论 GMs不安运动阶段质量评估是预测婴幼儿神经系统疾病的一种有效方法,但不推荐单独使用.【期刊名称】《浙江医学》【年(卷),期】2016(038)014【总页数】5页(P1161-1165)【关键词】全身运动;不安运动阶段;婴幼儿;神经系统疾病;脑性瘫痪;Meta分析【作者】门光国;王凤敏;崔英波【作者单位】315012 宁波市妇女儿童医院新生儿科;315012 宁波市妇女儿童医院新生儿科;315012 宁波市妇女儿童医院新生儿科【正文语种】中文全身运动（general movements，GMs）是一种复杂的动作，包括头部、躯干、手臂和腿的运动，出现于胎儿早期并持续到出生后3～4个月。
近年来，GMs质量评估对婴幼儿脑性瘫痪（CP）等神经系统疾病的预测价值得到越来越多证据支持[1-2]。
Infectious Diseases Society of America American
Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in AdultsLionel A.Mandell,1,a Richard G.Wunderink,2,a Antonio Anzueto,3,4John G.Bartlett,7G.Douglas Campbell,8Nathan C.Dean,9,10Scott F.Dowell,11Thomas M.File,Jr.12,13Daniel M.Musher,5,6Michael S.Niederman,14,15 Antonio Torres,16and Cynthia G.Whitney111McMaster University Medical School,Hamilton,Ontario,Canada;2Northwestern University Feinberg School of Medicine,Chicago,Illinois;3University of Texas Health Science Center and4South Texas Veterans Health Care System,San Antonio,and5Michael E.DeBakey Veterans Affairs Medical Center and6Baylor College of Medicine,Houston,Texas;7Johns Hopkins University School of Medicine,Baltimore,Maryland;8Division of Pulmonary,Critical Care,and Sleep Medicine,University of Mississippi School of Medicine,Jackson;9Division of Pulmonary and Critical Care Medicine,LDS Hospital,and10University of Utah,Salt Lake City,Utah;11Centers for Disease Control and Prevention,Atlanta, Georgia;12Northeastern Ohio Universities College of Medicine,Rootstown,and13Summa Health System,Akron,Ohio;14State University of New York at Stony Brook,Stony Brook,and15Department of Medicine,Winthrop University Hospital,Mineola,New York;and16Cap de Servei de Pneumologia i Alle`rgia Respirato`ria,Institut Clı´nic del To`rax,Hospital Clı´nic de Barcelona,Facultat de Medicina,Universitat de Barcelona,Institut d’Investigacions Biome`diques August Pi i Sunyer,CIBER CB06/06/0028,Barcelona,Spain.EXECUTIVE SUMMARYImproving the care of adult patients with community-acquired pneumonia(CAP)has been the focus of many different organizations,and several have developed guidelines for management of CAP.Two of the most widely referenced are those of the Infectious Diseases Society of America(IDSA)and the American Thoracic Society(ATS).In response to confusion regarding dif-ferences between their respective guidelines,the IDSA and the ATS convened a joint committee to develop a unified CAP guideline document.The guidelines are intended primarily for use by emergency medicine physicians,hospitalists,and pri-mary care practitioners;however,the extensive litera-ture evaluation suggests that they are also an appro-Reprints or correspondence:Dr.Lionel A.Mandell,Div.of Infectious Diseases, McMaster University/Henderson Hospital,5th Fl.,Wing40,Rm.503,711 Concession St.,Hamilton,Ontario L8V1C3,Canada(lmandell@mcmaster.ca). This official statement of the Infectious Diseases Society of America(IDSA) and the American Thoracic Society(ATS)was approved by the IDSA Board of Directors on5November2006and the ATS Board of Directors on29September 2006.a Committee cochairs.Clinical Infectious Diseases2007;44:S27–72ᮊ2007by the Infectious Diseases Society of America.All rights reserved. 1058-4838/2007/4405S2-0001$15.00DOI:10.1086/511159priate starting point for consultation by specialists.Substantial overlap exists among the patients whomthese guidelines address and those discussed in the re-cently published guidelines for health care–associatedpneumonia(HCAP).Pneumonia in nonambulatoryresidents of nursing homes and other long-term carefacilities epidemiologically mirrors hospital-acquiredpneumonia and should be treated according to theHCAP guidelines.However,certain other patientswhose conditions are included in the designation ofHCAP are better served by management in accordancewith CAP guidelines with concern for specificpathogens.Implementation of Guideline Recommendations1.Locally adapted guidelines should be imple-mented to improve process of care variables andrelevant clinical outcomes.(Strong recommen-dation;level I evidence.)It is important to realize that guidelines cannot always account for individualvariation among patients.They are not intended to supplant physician judgmentwith respect to particular patients or special clinical situations.The IDSA considersadherence to these guidelines to be voluntary,with the ultimate determinationregarding their application to be made by the physician in the light of each patient’sindividual circumstances.at Lanzhou University on April 21, 2011Downloaded fromEnthusiasm for developing these guidelines derives,in large part,from evidence that previous CAP guidelines have led to improvement in clinically relevant outcomes.Consistently ben-eficial effects in clinically relevant parameters(listed in table3) followed the introduction of a comprehensive protocol(in-cluding a combination of components from table2)that in-creased compliance with published guidelines.Thefirst rec-ommendation,therefore,is that CAP management guidelines be locally adapted and implemented.Documented benefits.2.CAP guidelines should address a comprehensive set ofelements in the process of care rather than a single element in isolation.(Strong recommendation;level III evidence.)3.Development of local CAP guidelines should be directedtoward improvement in specific and clinically relevant outcomes.(Moderate recommendation;level III evidence.)Site-of-Care DecisionsAlmost all of the major decisions regarding management of CAP,including diagnostic and treatment issues,revolve around the initial assessment of severity.Site-of-care decisions (e.g.,hospital vs.outpatient,intensive care unit[ICU]vs. general ward)are important areas for improvement in CAP management.Hospital admission decision.4.Severity-of-illness scores,such as the CURB-65criteria(confusion,uremia,respiratory rate,low blood pressure, age65years or greater),or prognostic models,such as the Pneumonia Severity Index(PSI),can be used to iden-tify patients with CAP who may be candidates for out-patient treatment.(Strong recommendation;level I evidence.)5.Objective criteria or scores should always be supple-mented with physician determination of subjective fac-tors,including the ability to safely and reliably take oral medication and the availability of outpatient support re-sources.(Strong recommendation;level II evidence.) 6.For patients with CURB-65scoresу2,more-intensivetreatment—that is,hospitalization or,where appropriate and available,intensive in-home health care services—is usually warranted.(Moderate recommendation;level III evidence.)Physicians often admit patients to the hospital who could be well managed as outpatients and who would generally prefer to be treated as outpatients.Objective scores,such as the CURB-65score or the PSI,can assist in identifying patients who may be appropriate for outpatient care,but the use of such scores must be tempered by the physician’s determination of addi-tional critical factors,including the ability to safely and reliably take oral medication and the availability of outpatient support resources.ICU admission decision.7.Direct admission to an ICU is required for patients withseptic shock requiring vasopressors or with acute respi-ratory failure requiring intubation and mechanical ven-tilation.(Strong recommendation;level II evidence.)8.Direct admission to an ICU or high-level monitoring unitis recommended for patients with3of the minor criteriafor severe CAP listed in table4.(Moderate recommen-dation;level II evidence.)In some studies,a significant percentage of patients withCAP are transferred to the ICU in thefirst24–48h after hos-pitalization.Mortality and morbidity among these patients ap-pears to be greater than those among patients admitted directlyto the ICU.Conversely,ICU resources are often overstretchedin many institutions,and the admission of patients with CAPwho would not directly benefit from ICU care is also problem-atic.Unfortunately,none of the published criteria for severeCAP adequately distinguishes these patients from those forwhom ICU admission is necessary.In the present set of guide-lines,a new set of criteria has been developed on the basis ofdata on individual risks,although the previous ATS criteriaformat is retained.In addition to the2major criteria(needfor mechanical ventilation and septic shock),an expanded setof minor criteria(respiratory rate,130breaths/min;arterialoxygen pressure/fraction of inspired oxygen(PaO2/FiO2)ratio,!250;multilobar infiltrates;confusion;blood urea nitrogenlevel,120mg/dL;leukopenia resulting from infection;throm-bocytopenia;hypothermia;or hypotension requiring aggressivefluid resuscitation)is proposed(table4).The presence of atleast3of these criteria suggests the need for ICU care but willrequire prospective validation.Diagnostic Testing9.In addition to a constellation of suggestive clinical fea-tures,a demonstrable infiltrate by chest radiograph orother imaging technique,with or without supporting mi-crobiological data,is required for the diagnosis of pneu-monia.(Moderate recommendation;level III evidence.) Recommended diagnostic tests for etiology.10.Patients with CAP should be investigated for specificpathogens that would significantly alter standard(em-pirical)management decisions,when the presence ofsuch pathogens is suspected on the basis of clinical andepidemiologic clues.(Strong recommendation;level IIevidence.)Recommendations for diagnostic testing remain controver-sial.The overall low yield and infrequent positive impact onclinical care argue against the routine use of common tests,at Lanzhou University on April 21, 2011Downloaded fromsuch as blood and sputum cultures.Conversely,these cultures may have a major impact on the care of an individual patient and are important for epidemiologic reasons,including the antibiotic susceptibility patterns used to develop treatment guidelines.A list of clinical indications for more extensive di-agnostic testing(table5)was,therefore,developed,primarily on the basis of2criteria:(1)when the result is likely to change individual antibiotic management and(2)when the test is likely to have the highest yield.11.Routine diagnostic tests to identify an etiologic diagnosisare optional for outpatients with CAP.(Moderate rec-ommendation;level III evidence.)12.Pretreatment blood samples for culture and an expec-torated sputum sample for stain and culture(in patientswith a productive cough)should be obtained from hos-pitalized patients with the clinical indications listed intable5but are optional for patients without these con-ditions.(Moderate recommendation;level I evidence.)13.Pretreatment Gram stain and culture of expectoratedsputum should be performed only if a good-quality spec-imen can be obtained and quality performance measuresfor collection,transport,and processing of samples canbe met.(Moderate recommendation;level II evidence.)14.Patients with severe CAP,as defined above,should atleast have blood samples drawn for culture,urinary an-tigen tests for Legionella pneumophila and Streptococcuspneumoniae performed,and expectorated sputum sam-ples collected for culture.For intubated patients,an en-dotracheal aspirate sample should be obtained.(Mod-erate recommendation;level II evidence.)The most clear-cut indication for extensive diagnostic testing is in the critically ill CAP patient.Such patients should at least have blood drawn for culture and an endotracheal aspirate obtained if they are intubated;consideration should be given to more extensive testing,including urinary antigen tests for L.pneumophila and S.pneumoniae and Gram stain and culture of expectorated sputum in nonintubated patients.For inpa-tients without the clinical indications listed in table5,diagnostic testing is optional(but should not be considered wrong).Antibiotic TreatmentEmpirical antimicrobial therapy.Empirical antibiotic rec-ommendations(table7)have not changed significantly from those in previous guidelines.Increasing evidence has strength-ened the recommendation for combination empirical therapy for severe CAP.Only1recently released antibiotic has been added to the recommendations:ertapenem,as an acceptable b-lactam alternative for hospitalized patients with risk factors for infection with gram-negative pathogens other than Pseu-domonas aeruginosa.At present,the committee is awaiting fur-ther evaluation of the safety of telithromycin by the US Food and Drug Administration before making itsfinal recommen-dation regarding this drug.Recommendations are generally fora class of antibiotics rather than for a specific drug,unlessoutcome data clearly favor one drug.Because overall efficacyremains good for many classes of agents,the more potent drugsare given preference because of their benefit in decreasing therisk of selection for antibiotic resistance.Outpatient treatment15.Previously healthy and no risk factors for drug-resistantS.pneumoniae(DRSP)infection:A.A macrolide(azithromycin,clarithromycin,orerythromycin)(strong recommendation;level Ievidence)B.Doxycycline(weak recommendation;level IIIevidence)16.Presence of comorbidities,such as chronic heart,lung,liver,or renal disease;diabetes mellitus;alcoholism;ma-lignancies;asplenia;immunosuppressing conditions oruse of immunosuppressing drugs;use of antimicrobialswithin the previous3months(in which case an alter-native from a different class should be selected);or otherrisks for DRSP infection:A.A respiratoryfluoroquinolone(moxifloxacin,gem-ifloxacin,or levofloxacin[750mg])(strong rec-ommendation;level I evidence)B.A b-lactam plus a macrolide(strong recommen-dation;level I evidence)(High-dose amoxicillin[e.g.,1g3times daily]or amoxicillin-clavulanate[2g2times daily]is preferred;alternatives include cef-triaxone,cefpodoxime,and cefuroxime[500mg2times daily];doxycycline[level II evidence]is analternative to the macrolide.)17.In regions with a high rate(125%)of infection withhigh-level(MIC,у16m g/mL)macrolide-resistant S.pneumoniae,consider the use of alternative agents listedabove in recommendation16for any patient,includingthose without comorbidities.(Moderate recommenda-tion;level III evidence.)Inpatient,non-ICU treatment18.A respiratoryfluoroquinolone(strong recommendation;level I evidence)19.A b-lactam plus a macrolide(strong recommendation;level I evidence)(Preferred b-lactam agents include ce-fotaxime,ceftriaxone,and ampicillin;ertapenem for se-lected patients;with doxycycline[level III evidence]as analternative to the macrolide.A respiratoryfluoroquino-lone should be used for penicillin-allergic patients.)Increasing resistance rates have suggested that empiricaltherapy with a macrolide alone can be used only for the treat-at Lanzhou University on April 21, 2011Downloaded fromment of carefully selected hospitalized patients with nonsevere disease and without risk factors for infection with drug-re-sistant pathogens.However,such monotherapy cannot be routinely recommended.Inpatient,ICU treatment20.A b-lactam(cefotaxime,ceftriaxone,or ampicillin-sul-bactam)plus either azithromycin(level II evidence)orafluoroquinolone(level I evidence)(strong recommen-dation)(For penicillin-allergic patients,a respiratoryflu-oroquinolone and aztreonam are recommended.) 21.For Pseudomonas infection,use an antipneumococcal,antipseudomonal b-lactam(piperacillin-tazobactam,ce-fepime,imipenem,or meropenem)plus either cipro-floxacin or levofloxacin(750-mg dose)orthe above b-lactam plus an aminoglycoside andazithromycinorthe above b-lactam plus an aminoglycoside and an an-tipneumococcalfluoroquinolone(for penicillin-allergicpatients,substitute aztreonam for the above b-lactam).(Moderate recommendation;level III evidence.) 22.For community-acquired methicillin-resistant Staphy-lococcus aureus infection,add vancomycin or linezolid.(Moderate recommendation;level III evidence.) Infections with the overwhelming majority of CAP pathogens will be adequately treated by use of the recommended empirical regimens.The emergence of methicillin-resistant S.aureus as a CAP pathogen and the small but significant incidence of CAP due to P.aeruginosa are the exceptions.These pathogens occur in specific epidemiologic patterns and/or with certain clinical presentations,for which empirical antibiotic coverage may be warranted.However,diagnostic tests are likely to be of high yield for these pathogens,allowing early discontinuation of empirical treatment if results are negative.The risk factors are included in the table5recommendations for indications for increased diagnostic testing.Pathogens suspected on the basis of epidemiologic considerations.Risk factors for other uncommon etiologies of CAP are listed in table8,and recommendations for treatment are included in table9.Pathogen-directed therapy.23.Once the etiology of CAP has been identified on thebasis of reliable microbiological methods,antimicrobialtherapy should be directed at that pathogen.(Moderaterecommendation;level III evidence.)24.Early treatment(within48h of the onset of symptoms)with oseltamivir or zanamivir is recommended for in-fluenza A.(Strong recommendation;level I evidence.)e of oseltamivir and zanamivir is not recommendedfor patients with uncomplicated influenza with symp-toms for148h(level I evidence),but these drugs maybe used to reduce viral shedding in hospitalized patientsor for influenza pneumonia.(Moderate recommenda-tion;level III evidence.)Pandemic influenza26.Patients with an illness compatible with influenza andwith known exposure to poultry in areas with previousH5N1infection should be tested for H5N1infection.(Moderate recommendation;level III evidence.)27.In patients with suspected H5N1infection,droplet pre-cautions and careful routine infection control measuresshould be used until an H5N1infection is ruled out.(Moderate recommendation;level III evidence.)28.Patients with suspected H5N1infection should be treatedwith oseltamivir(level II evidence)and antibacterialagentstargeting S.pneumoniae and S.aureus,the most commoncauses of secondary bacterial pneumonia in patients withinfluenza(level III evidence).(Moderate recommendation.)Time tofirst antibiotic dose.29.For patients admitted through the emergency depart-ment(ED),thefirst antibiotic dose should be admin-istered while still in the ED.(Moderate recommendation;level III evidence.)Rather than designating a specific window in which to initiate treatment,the committee felt that hospitalized patients withCAP should receive thefirst antibiotic dose in the ED.Switch from intravenous to oral therapy.30.Patients should be switched from intravenous to oraltherapy when they are hemodynamically stable and im-proving clinically,are able to ingest medications,andhave a normally functioning gastrointestinal tract.(Strong recommendation;level II evidence.)31.Patients should be discharged as soon as they are clin-ically stable,have no other active medical problems,andhave a safe environment for continued care.Inpatientobservation while receiving oral therapy is not necessary.(Moderate recommendation;level II evidence.)Duration of antibiotic therapy.32.Patients with CAP should be treated for a minimum of5days(level I evidence),should be afebrile for48–72h,and should have no more than1CAP-associated sign ofclinical instability(table10)before discontinuation oftherapy(level II evidence).(Moderate recommendation.)at Lanzhou University on April 21, 2011Downloaded from33.A longer duration of therapy may be needed if initial therapy was not active against the identified pathogen or if it was complicated by extrapulmonary infection,such as meningitis or endocarditis.(Weak recommen-dation;level III evidence.)Other Treatment Considerations 34.Patients with CAP who have persistent septic shock de-spite adequate fluid resuscitation should be considered for treatment with drotrecogin alfa activated within 24h of admission.(Weak recommendation;level II evidence.)35.Hypotensive,fluid-resuscitated patients with severe CAP should be screened for occult adrenal insufficiency.(Moderate recommendation;level II evidence.)36.Patients with hypoxemia or respiratory distress should receive a cautious trial of noninvasive ventilation unless they require immediate intubation because of severe hy-poxemia (PaO 2/FiO 2ratio,!150)and bilateral alveolar infiltrates.(Moderate recommendation;level I evidence.)37.Low-tidal-volume ventilation (6cm 3/kg of ideal body weight)should be used for patients undergoing venti-lation who have diffuse bilateral pneumonia or acute respiratory distress syndrome.(Strong recommenda-tion;level I evidence.)Management of Nonresponding Pneumonia Definitions and classification.38.The use of a systematic classification of possible causes of failure to respond,based on time of onset and type of failure (table 11),is recommended.(Moderate rec-ommendation;level II evidence.)As many as 15%of patients with CAP may not respond appropriately to initial antibiotic therapy.A systematic ap-proach to these patients (table 11)will help to determine the cause.Because determination of the cause of failure is more accurate if the original microbiological etiology is known,risk factors for nonresponse or deterioration (table 12)figure prom-inently in the list of situations in which more aggressive and/or extensive initial diagnostic testing is warranted (table 5).Prevention (see table 13)39.All persons у50years of age,others at risk for influenza complications,household contacts of high-risk persons,and health care workers should receive inactivated in-fluenza vaccine as recommended by the Advisory Com-mittee on Immunization Practices,Centers for Disease Control and Prevention.(Strong recommendation;level I evidence.)40.The intranasally administered live attenuated vaccine isan alternative vaccine formulation for some persons 5–49years of age without chronic underlying diseases,in-cluding immunodeficiency,asthma,or chronic medical conditions.(Strong recommendation;level I evidence.)41.Health care workers in inpatient and outpatient settingsand long-term care facilities should receive annual in-fluenza immunization.(Strong recommendation;level Ievidence.)42.Pneumococcal polysaccharide vaccine is recommended for persons у65years of age and for those with selected high-risk concurrent diseases,according to current Ad-visory Committee on Immunization Practices guidelines.(Strong recommendation;level II evidence.)43.Vaccination status should be assessed at the time of hos-pital admission for all patients,especially those withmedical illnesses.(Moderate recommendation;level IIIevidence.)44.Vaccination may be performed either at hospital dis-charge or during outpatient treatment.(Moderate rec-ommendation;level III evidence.)45.Influenza vaccine should be offered to persons at hospitaldischarge or during outpatient treatment during the fall and winter.(Strong recommendation;level III evidence.)46.Smoking cessation should be a goal for persons hospi-talized with CAP who smoke.(Moderate recommen-dation;level III evidence.)47.Smokers who will not quit should also be vaccinated for both pneumococcus and influenza.(Weak recommen-dation;level III evidence.)48.Cases of pneumonia that are of public health concern should be reported immediately to the state or local health department.(Strong recommendation;level III evidence.)49.Respiratory hygiene measures,including the use of hand hygiene and masks or tissues for patients with cough,should be used in outpatient settings and EDs as a means to reduce the spread of respiratory infections.(Strong recommendation;level III evidence.)INTRODUCTIONImproving the care of patients with community-acquired pneu-monia (CAP)has been the focus of many different organiza-tions.Such efforts at improvement in care are warranted,be-cause CAP ,together with influenza,remains the seventh leadingcause of death in the United States [1].According to one es-timate,915,900episodes of CAP occur in adults у65years of age each year in the United States [2].Despite advances in antimicrobial therapy,rates of mortality due to pneumonia have not decreased significantly since penicillin became rou-tinely available [3].at Lanzhou University on April 21, 2011 Downloaded fromGroups interested in approaches to the management of CAP include professional societies,such as the American Thoracic Society(ATS)and the Infectious Diseases Society of America (IDSA);government agencies or their contract agents,such as the Center for Medicare and Medicaid Services and the De-partment of Veterans Affairs;and voluntary accrediting agen-cies,such as the Joint Commission on Accreditation of Health-care Organizations.In addition,external review groups and consumer groups have chosen CAP outcomes as major quality indicators.Such interest has resulted in numerous guidelines for the management of CAP[4].Some of these guidelines represent truly different perspectives,including differences in health care systems,in the availability of diagnostic tools or therapeutic agents,or in either the etiology or the antibiotic susceptibility of common causative microorganisms.The most widely referenced guidelines in the United States have been those published by the ATS[5,6]and the IDSA[7–9]. Differences,both real and imagined,between the ATS and IDSA guidelines have led to confusion for individual physicians, as well as for other groups who use these published guidelines rather than promulgating their own.In response to this con-cern,the IDSA and the ATS convened a joint committee to develop a unified CAP guideline document.This document represents a consensus of members of both societies,and both governing councils have approved the statement.Purpose and scope.The purpose of this document is to update clinicians with regard to important advances and con-troversies in the management of patients with CAP.The com-mittee chose not to address CAP occurring in immunocom-promised patients,including solid organ,bone marrow,or stem cell transplant recipients;patients receiving cancer chemother-apy or long-term(130days)high-dose corticosteroid treat-ment;and patients with congenital or acquired immunodefi-ciency or those infected with HIV who have CD4cell counts !350cells/mm3,although many of these patients may be in-fected with the same microorganisms.Pneumonia in children (р18years of age)is also not addressed.Substantial overlap exists among the patients these guidelines address and those discussed in the recently published guidelines for health care–associated pneumonia(HCAP)[10].Two issues are pertinent:(1)an increased risk of infection with drug-resistant isolates of usual CAP pathogens,such as Streptococcus pneumoniae,and(2)an increased risk of infection with less common,usually hospital-associated pathogens,such as Pseu-domonas and Acinetobacter species and methicillin-resistant Staphylococcus aureus(MRSA).Pneumonia in nonambulatory residents of nursing homes and other long-term care facilities epidemiologically mirrors hospital-acquired pneumonia and should be treated according to the HCAP guidelines.However, certain other patients whose conditions are included under the designation of HCAP are better served by management in ac-cordance with CAP guidelines with concern for specific path-ogens.For example,long-term dialysis alone is a risk for MRSAinfection but does not necessarily predispose patients to infec-tion with other HCAP pathogens,such as Pseudomonas aeru-ginosa or Acinetobacter species.On the other hand,certain pa-tients with chronic obstructive pulmonary disease(COPD)areat greater risk for infection with Pseudomonas species but notMRSA.These issues will be discussed in specific sections below.The committee started with the premise that mortality dueto CAP can be decreased.We,therefore,have placed the greatest emphasis on aspects of the guidelines that have been associatedwith decreases in mortality.For this reason,the document fo-cuses mainly on management and minimizes discussions ofsuch factors as pathophysiology,pathogenesis,mechanisms ofantibiotic resistance,and virulence factors.The committee recognizes that the majority of patients withCAP are cared for by primary care,hospitalist,and emergency medicine physicians[11],and these guidelines are,therefore,directed primarily at them.The committee consisted of infec-tious diseases,pulmonary,and critical care physicians with in-terest and expertise in pulmonary infections.The expertise ofthe committee and the extensive literature evaluation suggestthat these guidelines are also an appropriate starting point for consultation by these types of physicians.Although much of the literature cited originates in Europe,these guidelines are oriented toward the United States and Can-ada.Although the guidelines are generally applicable to otherparts of the world,local antibiotic resistance patterns,drug availability,and variations in health care systems suggest thatmodification of these guidelines is prudent for local use. Methodology.The process of guideline developmentstarted with the selection of committee cochairs by the presi-dents of the IDSA[12]and ATS[13],in consultation withother leaders in the respective societies.The committee cochairswere charged with selection of the rest of the committee.TheIDSA members were those involved in the development ofprevious IDSA CAP guidelines[9],whereas ATS members werechosen in consultation with the leadership of the Mycobacteria Tuberculosis and Pulmonary Infection Assembly,with inputfrom the chairs of the Clinical Pulmonary and Critical Care mittee members were chosen to represent dif-fering expertise and viewpoints on the various topics.One ac-knowledged weakness of this document is the lack of repre-sentation by primary care,hospitalist,and emergency medicine physicians.The cochairs generated a general outline of the topics to becovered that was then circulated to committee members forinput.A conference phone call was used to review topics andto discuss evidence grading and the general aims and expec-tations of the document.The topics were divided,and com-mittee members were assigned by the cochairs and chargedat Lanzhou University on April 21, 2011Downloaded from。
反就业性别歧视英文论文
The gender employment discrimination can be divided into two types – direct discrimination and indirect discrimination by expression. Direct discrimination, also known as exterior discrimination, is that employers regard expressly prohibited sex discrimination in law as a part of the measures of employment. It is one of the most obvious forms of sexual employment discrimination. As in some advertisement, employers clearly point out that they will not hire woman, women and men have different standards of measurement or women are refused directly to have promotion opportunities in the inner regulation. Indirect discrimination, also known as discrimination of Negative impact, is saying that employers implement a neutral and fair employment practices ostensibly, however, the result makes adverse effects on specific groups protected by sexual employment discrimination laws, which may constitute gender employment discrimination. Unless the employer can prove that the employment practices is relate to "about work execution" or “measurable to work capability”. In other words, if a person is belong to specific legal protection group with the typical characteristics of a statutory groups, employer groups treat the person and others who are not belong to the groups with the same recruitment, selection, assessment and other procedures related to labor rights or condition, and the results will not help the group. This situation constitutes indirect discrimination. But according to the law, for rectifying discrimination already existing in company or society, company give a statutory group (for example, women with disabilities) preferential treatments, which not constitute sexual discrimination in employment. As a reasonable remedy, positive actions shall be affirmed by law.
Macroeconomic dynamics and credit risk：A global perspective
Macroeconomic Dynamics and Credit Risk:A Global Perspective∗M.Hashem PesaranUniversity of Cambridge and USCTil Schuermann†Federal Reserve Bank of New York and Wharton Financial Institutions CenterBjörn-Jakob Treutler‡Mercer Oliver Wyman and Otto Beisheim Graduate School of Management,WHUScott M.WeinerBalliol College,University of OxfordApril12,2005AbstractThis paper presents a new approach to modeling conditional credit loss distributions.Asset value changes offirms in a credit portfolio are linked to a dynamic global macroeconometric model,allowingmacro effects to be isolated from idiosyncratic shocks from the perspective of default(and hence loss).Default probabilities are driven primarily by howfirms are tied to business cycles,both domestic andforeign,and how business cycles are linked across countries.We allow forfirm-specific business cycleeffects and the heterogeneity offirm default thresholds using credit ratings.The model can be used,forexample,to compute the effects of a hypothetical negative equity price shock in South East Asia on theloss distribution of a credit portfolio with global exposures over one or more quarters.We show that theeffects of such shocks on losses are asymmetric and non-proportional,reflecting the highly non-linearnature of the credit risk model.Keywords:Risk management,economic interlinkages,loss forecasting,default correlationJEL Codes:C32,E17,G20∗In preparing this version we have benefited greatly from comments and suggestions by Carlo Favero,Mark Flannery,Monika Piazzesi and three anonymous referees.We would also like to acknowledge helpful comments from Roland Demmel,Joshua Rosenberg,Jan-Hendrik Schmidt and Jim Wilcox,as well as participants at the C.R.E.D.I.T.conference,Venice,September 2003,the IGIER-PIER conference,Milan,October2003,and seminar participants at the Judge Institute of Management, Cambridge University,University of Southern California,the Federal Reserve Bank of San Francisco,Rutgers University and Baruch College.We would also like to thank Sam Hanson for his excellent research assistance with estimating the default thresholds.†Any views expressed represent those of the author only and not necessarily those of the Federal Reserve Bank of New York or the Federal Reserve System.‡Any views expressed represent those of the author only and not necessarily those of Mercer Oliver Wyman.1IntroductionRisk management in general and credit risk analysis in particular has been the focus of extensive research in the past several years.Credit risk is the dominant source of risk for banks and the subject of strict regulatory oversight and policy debate.More recently,the proposal by the Bank for International Settlements(BIS)to reform the regulation of bank capital for credit risk(known as the New Basel Accord,or BIS2)has initiated debates on a number of issues in the literature.1 One of the issues under discussion centers on the effects of business cycles,especially of severe economic downturns,on bank risk and value-at-risk capital requirements(Carpenter,Whitesell and Zakrajšek2001,Carey2002,Allen and Saunders2004).However,this discussion has been taking place largely without the benefit of an explicit model that links the loss distribution of a bank’s credit portfolio to the evolution of directly observable macroeconomic factors at national and global levels.Given the increasing interdependencies in the global economy,risk managers of commercial and central banks alike may well be interested in questions like“What would be the impact on the credit loss distribution of a given bank(or banks)in a given region if there were large unfavorable shocks to equity prices,GDP or interest rates in that or other regions?”The purpose of this paper is to show how global macroeconometric models can be linked to firm specific return processes which are an integral part of Merton-type credit risk models so that quantitative answers to such questions can be obtained.We propose a combined model of credit losses contingent on the macroeconomy that is able to distinguish between default(and loss)due to systematic versus idiosyncratic(orfirm specific)shocks,providing an explicit channel for modeling default correlations.This enables us to conduct simulation experiments on the effect of changes in observable macroeconomic dynamics on credit risk.In providing such a linkage,the main conceptual challenge is to allow forfirm-specific business cycle effects and the heterogeneity of default probabilities acrossfirms.Standard credit risk models pioneered by Vasicek(1987)and elaborated in Vasicek(1991,2002)and Gordy(2003),adapt the option-based approach of Merton(1974)and allow for business cycle effects generally via one or more unobserved systematic risk factors.They assume that the processes generating asset values and the default thresholds are homogeneous acrossfirms.The parameters of the loss distribution are then identified byfixing the cross-firm correlation of asset returns and the mean default rate of the credit portfolio.Operational versions of the Vasicek model,e.g.by KMV,allow forfirm heterogeneity by making use of balance sheets,income statements and other similar reports issued by thefirm.This process inevitably involves a certain degree of subjective evaluation,however, and the outcome is generally proprietary information.21For details of BIS2see BIS(2001,2004),and for an account of the debates see,for example,Jones and Mingo (1998),and Altman,Bharath and Saunders(2002).2Credit portfolio models also differ in the way they model changes to thefirms’value.Some models operate on a mark-to-market basis by looking at the change of market value of credit assets based on credit migration and the termExamples of credit risk portfolio models in the professional literature include Gupton,Finger and Bhatia’s(1997)CreditMetrics,KMV’s PortfolioManager,and the actuarial approach employed by CSFB’s CreditRisk+(Credit Suisse First Boston1997)where the key risk driver is the variable mean default rate in the economy.Wilson’s(1997a,b)model(CreditPortfolioView)is an exception. He allows for the macroeconomic variables to influence afirm’s probability of default using a pooled logit specification.However,because the defaults are grouped,typically by industry,and modeled at the(single country)national level,anyfirm-specific heterogeneity is lost in the estimation process. For detailed comparisons,see Koyluoglu and Hickman(1998),Crouhy,Galai and Mark(2000), Gordy(2000)and Saunders and Allen(2002).In this paper we depart from the literature in two important respects.First,we model individual firm returns(taken as proxies for changes in asset values)in terms of a number of directly observable contemporaneous risk factors,such as changes in equity indices,interest rates,inflation,real money balances,oil prices and output,both domestic and foreign.In this way we allow for the possible differential impacts of macroeconomic factors on the evolution offirm’s asset values,and as such their default probabilities.Second,using historical observations on mean returns,volatility and default frequencies offirms for a particular credit rating,we computefirm-specific default threshold-equity ratios under the assumption that twofirms with identical credit ratings are likely to have similar default threshold-equity ratios.Thus we are able to provide an empirical implementation of the Merton model using only two pieces of publicly available information for eachfirm,namely market returns and credit ratings,in a multi-country setting.The problem of obtaining accurate information about the health of afirm,while not new,is particularly relevant for modelingfirms’bankruptcy or default.Our approach has the advantage that it does not rely onfirm-specific accounting data which are at best noisy and at worst biased due to the information asymmetries between company managers(agents)and share/debt holders (principals).Rating agencies are likely to have access to private information about thefirm’s past performance and its current management,in addition to public information from balance sheets and company reports,in arriving at theirfirm-specific credit ratings.In the pursuit of better ratings, companies have more of an incentive to reveal(some of)their private information to the credit rating agencies than to their debt-holders,very much in the same spirit that second—hand car dealers have the incentive to reveal information about the cars they offer for sale by the duration of the guarantees and other after-sales services that they provide.Moreover,basing the analysis strictly on accounting data would make it difficult to harmonize information across different accounting standards and bankruptcy codes from different countries,a source of heterogeneity presumably addressed by rating agencies.structure of credit spreads(CreditMetrics).Others focus on predicting default losses(so-called default mode models such as CSFB’s CreditRisk+).Yet there are other approaches that allow for both(e.g.KMV’s PortfolioManager, Wilson’s CreditPortfolioView).In short,in our framework the portfolio loss distribution is driven byfirms’credit ratings and how their returns are tied to business cycles,both domestic and foreign,and how business cycles are linked across countries.This is in contrast to credit risk analyses that explicitly focus on modeling of individualfirm defaults,using panel probit or logit specifications(Altman and Saunders1997, Lennox1999).Since defaults are rare,to obtain sensible estimates these applications tend to impose strong homogeneity assumptions on the parameters,which could bias the estimates.For instance, it is impossible to allow for anyfirm-specific(e.g.fixed)effects.The probit/logit approach is also difficult to adapt for the analysis of multi-period credit loss distributions,whilst our approach can be readily extended for such purposes.3To link thefirm-specific returns to business cycle factors we shall make use of the global vector autoregressive(GVAR)macroeconometric model recently developed by Pesaran,Schuermann and Weiner(2004)—hereafter PSW.This model is composed of vector error-correcting models(VECM) estimated for individual countries(or regions),which are then combined into a global model that takes account of both intra-and inter-country/regional interactions.The model uses domestic macroeconomic variables such as GDP,inflation,the level of short term interest rates,exchange rate,equity prices(when applicable)and real money balances.These are related to corresponding foreign variables constructed exclusively to match the international trade pattern of the country under consideration.Because of the global nature of the model,we can analyze how a shock to one specific macroeconomic variable affects other macroeconomic variables,even(and especially) across countries,as well as shocks to risk factors,e.g.oil prices,affecting all regions.We examine the credit risk of afictitious corporate loan portfolio and its exposure to a wide range of observable risk factors in the global economy.We model afirm’s probability of default as a function of those risk factors but assume for simplicity that loss given default is an exogenously given random variable whose specific parameterization can vary by ing thefirm-specific return regressions and the GVAR model,single-and multi-period credit loss distributions of a given portfolio are then obtained through Monte Carlo simulations.Our baseline expected losses are quite reasonable when compared with actual industry loan charge-offs.For example,expected loss over the course of four quarters is about58bp(basis points)of exposure,compared with89bp,the average net charge-offs(loans charged offless amount recovered over total loans)for the U.S.banking industry from1987to2003.When compared with the actual industry charge-offs matched by our forecast horizon,namely2000Q1,the difference is even smaller:those were56bp(at an annual rate).Much of the fat-tailedness of our loss distribution is,however,due to the relatively small number offirms(119in our portfolio)which entails a substantial degree of diversifiable idiosyncratic risk.Once this is controlled for(by including‘copies’of the existingfirms within the portfolio),the EL to VaR multiples are in line with those obtained by others(e.g.Carey2002who has about500exposures).For instance,the tail values at99%and 3A recent exception is Duffie and Wang(2003)who forecast default intensities over multiple periods.99.5%are around three to four times expected losses.Moreover,when we impose extreme shocks such as those seen during the Great Depression,VaR is more than triple the baseline scenario, also consistent with Carey’s results.Wefind further that symmetric shocks to the observable risk factors do not result in correspondingly symmetric loss outcomes reflecting the nonlinear nature of the credit risk model.In attempting to provide a formal link between credit risk and the macro-economy we have been forced to make many difficult choices.First,we confined our analysis to publicly traded companies with a sufficiently long credit rating history.We assume that this credit rating is a sufficient summary statistic of unconditional default risk,meaning that we take credit ratings as the business cycle-neutral,‘common currency’of default risk across different geographies,legislations and accounting standards.But we allow forfirm-specific conditional default probabilities over the course of the business cycle.To do this we need three different tools:(i)a model of the systematic (macroeconomic)risk factors,(ii)firm returns and how they are linked to those factors,and(iii)firm default thresholds.The GVAR satisfies thefirst requirement,and the link tofirms is done throughfirm-level return regressions by allowing the loadings on the macro-variables to befirm specific.The default thresholds are identified by assuming that they are the same within a rating category.4Clearly,other modeling strategies and identification schemes can be adopted.The present paper demonstrates that such an approach to credit risk modeling is in fact feasible.Our model is particularly suited for an international and multi-factor interpretation of the standard corporatefinance view offirm risk:total risk is the sum of systematic and idiosyncratic (i.e.firm-specific)risk.The GVAR is ostensibly a global model of systematic risk and its dynamics. Having a model of those factor dynamics can go a long way to understandingfirm risk(and return)characteristics and to address specific risk management related questions.One which we find particularly valuable is the ability to rank-order possible shock scenarios.Given a particular portfolio of credit exposures,is a1σshock(one standard error shock)to Japanese money supply more damaging(or beneficial,depending on the sign of the shock)than a1σshock to South East Asian or U.S.equity markets?What will the portfolio loss distribution look like one year from now?What if the portfolio changes?Such counterfactual questions are central to policy analysis, be it by commercial or central bankers who might wish to investigate the impact on a representative bank portfolio in their country of various economic shocks in other countries.If the model is not compact enough,it cannot be practically used in this repetitive fashion.The remainder of the paper is as follows:Section2provides an overview of the alternative 4The bankruptcy models of Altman(1968),Lennox(1999)and Shumway(2001)generatefirm specific default forecasts,as does the industry model by KMV(Kealhofer and Kurbat(2002)).However,all of these studies impose more significant parameter homogeneity than we do,and they focus on just one country at a time(the U.S.and U.K in this list),and thus do not address the formidable challenges of point in time bankruptcy forecasting with a multi-country portfolio.approaches to credit portfolio modeling and puts forward our proposed approach.Section3briefly discusses the GVAR model and shows how it is linked to the credit risk model.Mathematical expressions for the conditional one-period and multi-period loss distributions of a given credit portfolio under various shock scenarios are also obtained.Section4provides an empirical analysis of the impact of the different types of shocks(to output,money supply,equity and oil prices)on the loss distribution.Section5offers some concluding remarks.2Credit Portfolio ModelingCredit risk modeling is concerned with the tail properties of the loss distribution for a given portfolio of credit assets such as loans or bonds,and attempts to provide quantitative analysis of the extent to which the loss distribution varies with changes tofirm/industry-specific,national and global risk factors.It can be approached from the perspective of the individual loans that make up the portfolio,or it could be addressed by considering the return on the loan portfolio directly.In this paper we follow the former approach and simulate the portfolio loss distribution from the bottom up by considering how individualfirms default.Broadly speaking,there are two important variables describing asset/firm level credit risk:the probability of default(P D)and the loss given default(LGD).5Most of the work on P D and LGD has been done without explicit conditioning on business cycle variables;exceptions include Carey(1998),Frye(2000)and Altman,Brady,Resti and Sironi(2002).These studiesfind,perhaps not surprisingly,that losses are indeed worse in recessions.Tapping into information contained in equity returns(as opposed to credit spreads from debt instruments),Vassalou and Xing(2004) show that default risk varies with the business cycle.6Carey(2002),using re-sampling techniques, shows that mean losses during a recession such as1990/91in the U.S.are about the same as losses in the0.5%tail during an expansion.Bangia et al.(2002),using a regime switching approach,find that capital held by banks over a one-year horizon needs to be25-30%higher in a recession that in an expansion.In this paper we shall consider the loss distribution of the credit portfolio of afinancial institution such as a bank by conditioning on observable macroeconomic variables or factors.The conditional loss distribution allows for the effect of business cycle variations and captures such effects at a global level by explicitly taking account of the heterogeneous interconnections and interdependencies that exist between national and international factors.5The New Basel Accord explicitly mentions two additional variables:exposure at default and maturity.As these affect credit risk only moderately(and are often taken to be non-stochastic),our discussion will focus on the P D and LGD which are the two dominant determinants of the credit loss distribution.6See also the survey by Allen and Saunders(2004).2.1A Merton-Based Model of DefaultFollowing Merton(1974),afirm is expected to default when the value of its assets falls below a threshold value determined by its callable liabilities.The lender is effectively writing a put option on the assets of the borrowingfirm.If the value of thefirm falls below a certain threshold,the owners will put thefirm to the debt-holders.7Default,as considered by the rating agencies and banks,typically constitutes non-payment of interest or a coupon.8Thus there are three aspects which require modeling:(i)the evolution offirm value,(ii)the default threshold,and in a portfolio context,(iii)return correlations acrossfirms in the portfolio. We discuss thefirst two aspects in this section,while modeling of return correlations is treated in Section3.2.In Merton-type portfolio models,such as KMV,asset value and asset volatility are typically derived from balance sheet data as well as observable equity returns and(estimated) return volatility(see Kealhofer and Kurbat2002).The default threshold in these models is typically taken to be short term debt plus a proportion of long term debt.Asset value,asset volatility and the default threshold are then used to determine the distance from default.In what follows we advance an alternative approach where instead of using balance sheet data we make use offirm credit ratings.Consider afirm j in country or region i having asset values V ji,t at time t,and an outstanding stock of debt,D ji,t.Under the Merton(1974)model default occurs at the maturity date of the debt,t+H,if thefirm’s assets,V ji,t+H,are less than the face value of the debt at that time, D ji,t+H.This is in contrast with thefirst-passage models where default would occur thefirst time that V ji,t falls below a default boundary(or threshold)over the period t to t+H.9The default probabilities are computed with respect to the probability distribution of asset values at the terminal date,t+H in the case of the Merton model,and over the period from t to t+H in the case of thefirst-passage model.The Merton approach may be thought of as a European option and thefirst-passage approach as an American option.Our approach can be adapted to both of these models,but in what follows we focus on Merton’s specification.The value of thefirm at time t is the sum of debt and equity,namelyV ji,t=D ji,t+E ji,t,with D ji,t>0,(1) 7For a discussion of the power of Merton default prediction models see Falkenstein and Boral(2001)and Gemmill (2002)whofind that the Merton model generally does well in predicting default(Falkenstein and Boral)and credit spreads(Gemmill).Duffee(1999)points out that due to the continuous time diffusion processes underlying the Black Scholes formula,short-term default probabilities may be underestimated.8A similar default condition is used by regulators,e.g.in the New Basel Accord.See Section III.F,§146in BIS (2001).9Thefirst-passage approach is discussed in Black and Cox(1976).For a review see,for example,Duffie and Singleton(2003,Section3.2).More recent modeling approaches also allow for strategic default considerations,as in Mella-Barral and Perraudin(1997).or alternatively,V ji,t ji,t =1+E ji,tji,t.(2)Conditional on time t information,default will take place at time t+H ifV ji,t+H≤D ji,t+H,or using(2)ifE ji,t+HD ji,t+H≤0.(3) Equation(3)is restrictive in that it requires equity values to be negative before default occurs.Aside from non-trivial practical considerations having to do with arriving at an independent estimate of V ji,t,there are several reasons behind relaxing this condition.Because default is costly and violations to the absolute priority rule in bankruptcy proceedings are so common,in practice shareholders have an incentive to put thefirm into receivership even before the equity value of thefirm hits zero.10In fact,several authors have found that in65%to80%of bankruptcies,even shareholders receive something without debt-holders necessarily having been fully paid off(see,for instance,Eberhart and Weiss1998,and references therein).Moreover,we see in practice that equity values remain positive for insolventfirms.Similarly,the bank might also have an incentive of forcing thefirm to default once thefirm’s equity falls below a non-zero threshold,as well as an incentive to bypass the costly proceedings by agreeing to terms that yield positive value to the shareholders themselves.11The value of equity incorporates not only the asset values,but an option value that afirm in default may in fact recover before creditors take control of these assets.Finally,default in a credit relationship is typically a weaker condition than outright bankruptcy.An obligor may meet the technical default condition,e.g.a missed coupon payment,without subsequently going into bankruptcy.This distinction is particularly relevant in the banking-borrower relationship we seek to characterize.12In what follows we assume that default takes place if0<E ji,t+H<C ji,t+H,(4) where C ji,t+H is a positive default threshold which could vary over time and with thefirm’s par-ticular characteristics(such as region or industry sector).Natural candidates include quantitative factors such as leverage,profitability,firm age and perhaps size(most of which appear in models of firm default),as well as more qualitative factors such as management quality.13Obviously some of 10See,for instance,Leland and Toft(1996)who develop a model where default is determined endogenously without imposing a positive net worth condition.11For a treatment of this scenario,see Garbade(2001).12An excellent example of the joint borrower-lender decision process is given by Lawrence and Arshadi(1995).13For models of bankruptcy and default at thefirm level,see,for instance,Altman(1968),Lennox(1999),Shumway (2001),Chava and Jarrow(2004),Hillegeist,Keating,Cram and Lundstedt(2004),as well as a survey by Altman and Saunders(1997).these factors will be easier to observe and measure than others.The observable accounting-based factors are at best noisy and at worst could be biased,highlighting the information asymmetry between managers(agents)and share/debt-holders(principals).14Although our objective is not to build a default model per se,we face the same measurement difficulties and information asymmetries.To overcome them,we make use of the credit rating of afirm which we denote by R.15This will help us specifically in estimating the default thresholds needed in the determination of the default probabilities.Naturally,rating agencies have access to,and presumably make use of,private information about thefirm to arrive at theirfirm-specific credit rating,in addition to incorporating public information such as balance sheet information and,of course,equity returns.Thus we make the assumption that rating agencies benchmark their ratings on past returns and volatilities of allfirms that have been rated R in the past.Consider then a particular R−ratedfirm at time t,and assume that in arriving at their rating the credit rating agency uses the following standard geometric random walk model of equity values:ln(E R,t+1)=ln(E R t)+µR+σRηR,t+1,ηR,t+1∼IIDN(0,1),(5) with a non-zero drift,µR,and idiosyncratic Gaussian innovations with a zero mean andfixed volatility,σR.16We assume that conditional on data at time t,afirm’s rating does not change over the horizon(t,t+H),namelyln(E R,t+H)=ln(E R t)+HµR+σRHX s=1ηR,t+s,and by(4)default occurs ifln(E R,t+H)=ln(E R t)+HµR+σRHX s=1ηR,t+s<ln(C R,t+H),(6)or if the H-period change in equity value or return falls below the log-threshold-equity ratio:lnµE R,t+H E R t¶<lnµC R,t+H E R t¶.(7) Equation(7)tells us that the relative(rather than absolute)decline infirm value must be large enough over the horizon H to result in default,meaning it is independent of the size of thefirm. Firm size is an input to the credit rating determination;a smallfirm would need a larger equity cushion to withstand a given shocks than a largefirm with the same rating.14With this in mind,Duffie and Lando(2001)allow for the possibility of imperfect information about thefirm’s assets and default threshold in the context of afirst-passage model.15R may take on values such as’Aaa’,’Aa’,’Baa’,...,’Caa’in Moody’s terminology,or’AAA’,’AA’,’BBB’,...,’CCC’in S&P’s terminology.16Clearly non-Gaussian innovations can also be considered.But for quarterly data that we shall be working with Gausssian innovations seems a goodfirst approximation.Under the assumption that the evolution offirm equity value follows(5),ln(E R,t+H/E R t)may be approximated by the cumulative returns so that(7)can be re-written asHµR+σRHX s=1ηR,t+s<lnµC R,t+H R t¶.Therefore,the default probability for the R−ratedfirms at the terminal date t+H is given byπR(t,H)=ΦR,t+H /E R t RσR√H,(8) whereΦ(·)is the standard normal cumulative distribution function.Denote the H-period forward log threshold-equity ratio to beλR(t,H)=ln(C R,t+H/E R t)so thatλR(t,H)=HµR+Q R(t,H)σR√whereQ R(t,H)=Φ−1[πR(t,H)]is the quantile associated with the default probabilityπR(t,H).An estimate ofλR(t,H)can now be obtained using past observations on returns,r R t= ln(E R,t/E R,t−1),and the empirical default frequencies,ˆπR(t,H),of R−ratedfirms over a given period of say t=1,2,...,T.17Denoting the estimates ofµR andσR byˆµR,andˆσR,respectively, we haveˆλR(t,H)=HˆµR+ˆQ R(t,H)ˆσR√H,(9) whereˆµR andˆσ2R are the mean and standard deviation of returns offirms with rating R over the sample period,and18ˆQR(t,H)=Φ−1[ˆπR(t,H)].(10) The estimates ofˆµR andˆσR can also be updated using a rolling window of size7-8years(the average length of the business cycle).In practice,ˆπR(t,H)might not provide a reliable estimate ofπR(t,H)as it is likely to be based on very few defaults over any particular period(t,t+H).One possibility would be to use an average estimate ofλR(t,H)obtained over a reasonably long period of10to20years(on a rolling basis).For example,based on the sample observations t=1,2,...,T,we would haveˆλR(H)=HˆµR+ˆQ R(H)ˆσR√H,(11) 17An important source of heterogeneity is likely the large variation in bankruptcy laws and regulation across countries.However,by using rating agency default data,we use their homogeneous definition of default and are thus not subject to these heterogeneities.18In practice where there are many R-ratedfirms in a given period,average returns across all R-ratedfirms can be used to estimateˆµR.The computation ofˆσ2R is more involved and is described in a note available from the authors on request.。
Reproduction numbers and sub-threshold endemic equilibria for compartmental models of disease trans
Reproduction numbers and sub-threshold endemicequilibria for compartmental models of disease transmissionP.van den Driesschea,1,James Watmough b,*,2aDepartment of Mathematics and Statistics,University of Victoria,Victoria,BC,Canada V8W 3P4b Department of Mathematics and Statistics,University of New Brunswick,Fredericton,NB,Canada E3B 5A3Received 26April 2001;received in revised form 27June 2001;accepted 27June 2001Dedicated to the memory of John JacquezAbstractA precise definition of the basic reproduction number,R 0,is presented for a general compartmental disease transmission model based on a system of ordinary differential equations.It is shown that,if R 0<1,then the disease free equilibrium is locally asymptotically stable;whereas if R 0>1,then it is unstable.Thus,R 0is a threshold parameter for the model.An analysis of the local centre manifold yields a simple criterion for the existence and stability of super-and sub-threshold endemic equilibria for R 0near one.This criterion,together with the definition of R 0,is illustrated by treatment,multigroup,staged progression,multistrain and vector–host models and can be applied to more complex models.The results are significant for disease control.Ó2002Elsevier Science Inc.All rights reserved.Keywords:Basic reproduction number;Sub-threshold equilibrium;Disease transmission model;Disease control1.IntroductionOne of the most important concerns about any infectious disease is its ability to invade a population.Many epidemiological models have a disease free equilibrium (DFE)at whichtheMathematical Biosciences 180(2002)29–48/locate/mbs*Corresponding author.Tel.:+1-5064587323;fax:+1-5064534705.E-mail addresses:pvdd@math.uvic.ca (P.van den Driessche),watmough@unb.ca (J.Watmough).URL:http://www.math.unb.ca/$watmough.1Research supported in part by an NSERC Research Grant,the University of Victoria Committee on faculty research and travel and MITACS.2Research supported by an NSERC Postdoctoral Fellowship tenured at the University of Victoria.0025-5564/02/$-see front matter Ó2002Elsevier Science Inc.All rights reserved.PII:S0025-5564(02)00108-630P.van den Driessche,J.Watmough/Mathematical Biosciences180(2002)29–48population remains in the absence of disease.These models usually have a threshold parameter, known as the basic reproduction number,R0,such that if R0<1,then the DFE is locally as-ymptotically stable,and the disease cannot invade the population,but if R0>1,then the DFE is unstable and invasion is always possible(see the survey paper by Hethcote[1]).Diekmann et al.[2]define R0as the spectral radius of the next generation matrix.We write down in detail a general compartmental disease transmission model suited to heterogeneous populations that can be modelled by a system of ordinary differential equations.We derive an expression for the next generation matrix for this model and examine the threshold R0¼1in detail.The model is suited to a heterogeneous population in which the vital and epidemiological parameters for an individual may depend on such factors as the stage of the disease,spatial position,age or behaviour.However,we assume that the population can be broken into homo-geneous subpopulations,or compartments,such that individuals in a given compartment are indistinguishable from one another.That is,the parameters may vary from compartment to compartment,but are identical for all individuals within a given compartment.We also assume that the parameters do not depend on the length of time an individual has spent in a compart-ment.The model is based on a system of ordinary equations describing the evolution of the number of individuals in each compartment.In addition to showing that R0is a threshold parameter for the local stability of the DFE, we apply centre manifold theory to determine the existence and stability of endemic equilib-ria near the threshold.We show that some models may have unstable endemic equilibria near the DFE for R0<1.This suggests that even though the DFE is locally stable,the disease may persist.The model is developed in Section2.The basic reproduction number is defined and shown to bea threshold parameter in Section3,and the definition is illustrated by several examples in Section4.The analysis of the centre manifold is presented in Section5.The epidemiological ramifications of the results are presented in Section6.2.A general compartmental epidemic model for a heterogeneous populationConsider a heterogeneous population whose individuals are distinguishable by age,behaviour, spatial position and/or stage of disease,but can be grouped into n homogeneous compartments.A general epidemic model for such a population is developed in this section.Let x¼ðx1;...;x nÞt, with each x i P0,be the number of individuals in each compartment.For clarity we sort the compartments so that thefirst m compartments correspond to infected individuals.The distinc-tion between infected and uninfected compartments must be determined from the epidemiological interpretation of the model and cannot be deduced from the structure of the equations alone,as we shall discuss below.It is plausible that more than one interpretation is possible for some models.A simple epidemic model illustrating this is given in Section4.1.The basic reproduction number can not be determined from the structure of the mathematical model alone,but depends on the definition of infected and uninfected compartments.We define X s to be the set of all disease free states.That isX s¼f x P0j x i¼0;i¼1;...;m g:In order to compute R0,it is important to distinguish new infections from all other changes inpopulation.Let F iðxÞbe the rate of appearance of new infections in compartment i,Vþi ðxÞbe therate of transfer of individuals into compartment i by all other means,and VÀi ðxÞbe the rate oftransfer of individuals out of compartment i.It is assumed that each function is continuously differentiable at least twice in each variable.The disease transmission model consists of non-negative initial conditions together with the following system of equations:_x i¼f iðxÞ¼F iðxÞÀV iðxÞ;i¼1;...;n;ð1Þwhere V i¼VÀi ÀVþiand the functions satisfy assumptions(A1)–(A5)described below.Sinceeach function represents a directed transfer of individuals,they are all non-negative.Thus,(A1)if x P0,then F i;Vþi ;VÀiP0for i¼1;...;n.If a compartment is empty,then there can be no transfer of individuals out of the compartment by death,infection,nor any other means.Thus,(A2)if x i¼0then VÀi ¼0.In particular,if x2X s then VÀi¼0for i¼1;...;m.Consider the disease transmission model given by(1)with f iðxÞ,i¼1;...;n,satisfying con-ditions(A1)and(A2).If x i¼0,then f iðxÞP0and hence,the non-negative cone(x i P0, i¼1;...;n)is forward invariant.By Theorems1.1.8and1.1.9of Wiggins[3,p.37]for each non-negative initial condition there is a unique,non-negative solution.The next condition arises from the simple fact that the incidence of infection for uninfected compartments is zero.(A3)F i¼0if i>m.To ensure that the disease free subspace is invariant,we assume that if the population is free of disease then the population will remain free of disease.That is,there is no(density independent) immigration of infectives.This condition is stated as follows:(A4)if x2X s then F iðxÞ¼0and VþiðxÞ¼0for i¼1;...;m.The remaining condition is based on the derivatives of f near a DFE.For our purposes,we define a DFE of(1)to be a(locally asymptotically)stable equilibrium solution of the disease free model,i.e.,(1)restricted to X s.Note that we need not assume that the model has a unique DFE. Consider a population near the DFE x0.If the population remains near the DFE(i.e.,if the introduction of a few infective individuals does not result in an epidemic)then the population will return to the DFE according to the linearized system_x¼Dfðx0ÞðxÀx0Þ;ð2Þwhere Dfðx0Þis the derivative½o f i=o x j evaluated at the DFE,x0(i.e.,the Jacobian matrix).Here, and in what follows,some derivatives are one sided,since x0is on the domain boundary.We restrict our attention to systems in which the DFE is stable in the absence of new infection.That is, (A5)If FðxÞis set to zero,then all eigenvalues of Dfðx0Þhave negative real parts.P.van den Driessche,J.Watmough/Mathematical Biosciences180(2002)29–4831The conditions listed above allow us to partition the matrix Df ðx 0Þas shown by the following lemma.Lemma 1.If x 0is a DFE of (1)and f i ðx Þsatisfies (A1)–(A5),then the derivatives D F ðx 0Þand D V ðx 0Þare partitioned asD F ðx 0Þ¼F 000 ;D V ðx 0Þ¼V 0J 3J 4;where F and V are the m Âm matrices defined byF ¼o F i o x j ðx 0Þ !and V ¼o V i o x jðx 0Þ !with 16i ;j 6m :Further ,F is non-negative ,V is a non-singular M-matrix and all eigenvalues of J 4have positive real part .Proof.Let x 02X s be a DFE.By (A3)and (A4),ðo F i =o x j Þðx 0Þ¼0if either i >m or j >m .Similarly,by (A2)and (A4),if x 2X s then V i ðx Þ¼0for i 6m .Hence,ðo V i =o x j Þðx 0Þ¼0for i 6m and j >m .This shows the stated partition and zero blocks.The non-negativity of F follows from (A1)and (A4).Let f e j g be the Euclidean basis vectors.That is,e j is the j th column of the n Ân identity matrix.Then,for j ¼1;...;m ,o V i o x jðx 0Þ¼lim h !0þV i ðx 0þhe j ÞÀV i ðx 0Þh :To show that V is a non-singular M-matrix,note that if x 0is a DFE,then by (A2)and (A4),V i ðx 0Þ¼0for i ¼1;...;m ,and if i ¼j ,then the i th component of x 0þhe j ¼0and V i ðx 0þhe j Þ60,by (A1)and (A2).Hence,o V i =o x j 0for i m and j ¼i and V has the Z sign pattern (see Appendix A).Additionally,by (A5),all eigenvalues of V have positive real parts.These two conditions imply that V is a non-singular M-matrix [4,p.135(G 20)].Condition (A5)also implies that the eigenvalues of J 4have positive real part.Ã3.The basic reproduction numberThe basic reproduction number,denoted R 0,is ‘the expected number of secondary cases produced,in a completely susceptible population,by a typical infective individual’[2];see also [5,p.17].If R 0<1,then on average an infected individual produces less than one new infected individual over the course of its infectious period,and the infection cannot grow.Conversely,if R 0>1,then each infected individual produces,on average,more than one new infection,and the disease can invade the population.For the case of a single infected compartment,R 0is simply the product of the infection rate and the mean duration of the infection.However,for more complicated models with several infected compartments this simple heuristic definition of R 0is32P.van den Driessche,J.Watmough /Mathematical Biosciences 180(2002)29–48insufficient.A more general basic reproduction number can be defined as the number of new infections produced by a typical infective individual in a population at a DFE.To determine the fate of a‘typical’infective individual introduced into the population,we consider the dynamics of the linearized system(2)with reinfection turned off.That is,the system _x¼ÀD Vðx0ÞðxÀx0Þ:ð3ÞBy(A5),the DFE is locally asymptotically stable in this system.Thus,(3)can be used to de-termine the fate of a small number of infected individuals introduced to a disease free population.Let wi ð0Þbe the number of infected individuals initially in compartment i and letwðtÞ¼w1ðtÞ;...;w mðtÞðÞt be the number of these initially infected individuals remaining in the infected compartments after t time units.That is the vector w is thefirst m components of x.The partitioning of D Vðx0Þimplies that wðtÞsatisfies w0ðtÞ¼ÀV wðtÞ,which has the unique solution wðtÞ¼eÀVt wð0Þ.By Lemma1,V is a non-singular M-matrix and is,therefore,invertible and all of its eigenvalues have positive real parts.Thus,integrating F wðtÞfrom zero to infinity gives the expected number of new infections produced by the initially infected individuals as the vector FVÀ1wð0Þ.Since F is non-negative and V is a non-singular M-matrix,VÀ1is non-negative[4,p.137 (N38)],as is FVÀ1.To interpret the entries of FVÀ1and develop a meaningful definition of R0,consider the fate of an infected individual introduced into compartment k of a disease free population.The(j;k)entry of VÀ1is the average length of time this individual spends in compartment j during its lifetime, assuming that the population remains near the DFE and barring reinfection.The(i;j)entry of F is the rate at which infected individuals in compartment j produce new infections in compartment i. Hence,the(i;k)entry of the product FVÀ1is the expected number of new infections in com-partment i produced by the infected individual originally introduced into compartment k.Fol-lowing Diekmann et al.[2],we call FVÀ1the next generation matrix for the model and set R0¼qðFVÀ1Þ;ð4Þwhere qðAÞdenotes the spectral radius of a matrix A.The DFE,x0,is locally asymptotically stable if all the eigenvalues of the matrix Dfðx0Þhave negative real parts and unstable if any eigenvalue of Dfðx0Þhas a positive real part.By Lemma1, the eigenvalues of Dfðx0Þcan be partitioned into two sets corresponding to the infected and uninfected compartments.These two sets are the eigenvalues of FÀV and those ofÀJ4.Again by Lemma1,the eigenvalues ofÀJ4all have negative real part,thus the stability of the DFE is determined by the eigenvalues of FÀV.The following theorem states that R0is a threshold parameter for the stability of the DFE.Theorem2.Consider the disease transmission model given by(1)with fðxÞsatisfying conditions (A1)–(A5).If x0is a DFE of the model,then x0is locally asymptotically stable if R0<1,but un-stable if R0>1,where R0is defined by(4).Proof.Let J1¼FÀV.Since V is a non-singular M-matrix and F is non-negative,ÀJ1¼VÀF has the Z sign pattern(see Appendix A).Thus,sðJ1Þ<0()ÀJ1is a non-singular M-matrix;P.van den Driessche,J.Watmough/Mathematical Biosciences180(2002)29–483334P.van den Driessche,J.Watmough/Mathematical Biosciences180(2002)29–48where sðJ1Þdenotes the maximum real part of all the eigenvalues of the matrix J1(the spectral abscissa of J1).Since FVÀ1is non-negative,ÀJ1VÀ1¼IÀFVÀ1also has the Z sign pattern.Ap-plying Lemma5of Appendix A,with H¼V and B¼ÀJ1¼VÀF,we have ÀJ1is a non-singular M-matrix()IÀFVÀ1is a non-singular M-matrix:Finally,since FVÀ1is non-negative,all eigenvalues of FVÀ1have magnitude less than or equal to qðFVÀ1Þ.Thus,IÀFVÀ1is a non-singular M-matrix;()qðFVÀ1Þ<1:Hence,sðJ1Þ<0if and only if R0<1.Similarly,it follows thatsðJ1Þ¼0()ÀJ1is a singular M-matrix;()IÀFVÀ1is a singular M-matrix;()qðFVÀ1Þ¼1:The second equivalence follows from Lemma6of Appendix A,with H¼V and K¼F.The remainder of the equivalences follow as with the non-singular case.Hence,sðJ1Þ¼0if and only if R0¼1.It follows that sðJ1Þ>0if and only if R0>1.ÃA similar result can be found in the recent book by Diekmann and Heesterbeek[6,Theorem6.13].This result is known for the special case in which J1is irreducible and V is a positive di-agonal matrix[7–10].The special case in which V has positive diagonal and negative subdiagonal elements is proven in Hyman et al.[11,Appendix B];however,our approach is much simpler(see Section4.3).4.Examples4.1.Treatment modelThe decomposition of fðxÞinto the components F and V is illustrated using a simple treat-ment model.The model is based on the tuberculosis model of Castillo-Chavez and Feng[12,Eq.(1.1)],but also includes treatment failure used in their more elaborate two-strain model[12,Eq.(2.1)].A similar tuberculosis model with two treated compartments is proposed by Blower et al.[13].The population is divided into four compartments,namely,individuals susceptible to tu-berculosis(S),exposed individuals(E),infectious individuals(I)and treated individuals(T).The dynamics are illustrated in Fig.1.Susceptible and treated individuals enter the exposed com-partment at rates b1I=N and b2I=N,respectively,where N¼EþIþSþT.Exposed individuals progress to the infectious compartment at the rate m.All newborns are susceptible,and all indi-viduals die at the rate d>0.Thus,the core of the model is an SEI model using standard inci-dence.The treatment rates are r1for exposed individuals and r2for infectious individuals. However,only a fraction q of the treatments of infectious individuals are successful.Unsuc-cessfully treated infectious individuals re-enter the exposed compartment(p¼1Àq).The diseasetransmission model consists of the following differential equations together with non-negative initial conditions:_E¼b1SI=Nþb2TI=NÀðdþmþr1ÞEþpr2I;ð5aÞ_I¼m EÀðdþr2ÞI;ð5bÞ_S¼bðNÞÀdSÀb1SI=N;ð5cÞ_T¼ÀdTþr1Eþqr2IÀb2TI=N:ð5dÞProgression from E to I and failure of treatment are not considered to be new infections,but rather the progression of an infected individual through the various compartments.Hence,F¼b1SI=Nþb2TI=NB B@1C CA and V¼ðdþmþr1ÞEÀpr2IÀm Eþðdþr2ÞIÀbðNÞþdSþb1SI=NdTÀr1EÀqr2Iþb2TI=NB B@1C CA:ð6ÞThe infected compartments are E and I,giving m¼2.An equilibrium solution with E¼I¼0has the form x0¼ð0;0;S0;0Þt,where S0is any positive solution of bðS0Þ¼dS0.This will be a DFE if and only if b0ðS0Þ<d.Without loss of generality,assume S0¼1is a DFE.Then,F¼0b100;V¼dþmþr1Àpr2Àm dþr2;givingVÀ1¼1ðdþmþr1Þðdþr2ÞÀm pr2dþr2pr2m dþmþr1and R0¼b1m=ððdþmþr1Þðdþr2ÞÀm pr2Þ.A heuristic derivation of the(2;1)entry of VÀ1and R0are as follows:a fraction h1¼m=ðdþmþr1Þof exposed individuals progress to compartment I,a fraction h2¼pr2=ðdþr2Þof infectious individuals re-enter compartment E.Hence,a fractionh1of exposed individuals pass through compartment I at least once,a fraction h21h2passthroughat least twice,and a fraction h k 1h k À12pass through at least k times,spending an average of s ¼1=ðd þr 2Þtime units in compartment I on each pass.Thus,an individual introduced into com-partment E spends,on average,s ðh 1þh 21h 2þÁÁÁÞ¼s h 1=ð1Àh 1h 2Þ¼m =ððd þm þr 1Þðd þr 2ÞÀm pr 2Þtime units in compartment I over its expected lifetime.Multiplying this by b 1gives R 0.The model without treatment (r 1¼r 2¼0)is an SEI model with R 0¼b 1m =ðd ðd þm ÞÞ.The interpretation of R 0for this case is simpler.Only a fraction m =ðd þm Þof exposed individuals progress from compartment E to compartment I ,and individuals entering compartment I spend,on average,1=d time units there.Although conditions (A1)–(A5)do not restrict the decomposition of f i ðx Þto a single choice for F i ,only one such choice is epidemiologically correct.Different choices for the function F lead to different values for the spectral radius of FV À1,as shown in Table 1.In column (a),treatment failure is considered to be a new infection and in column (b),both treatment failure and pro-gression to infectiousness are considered new infections.In each case the condition q ðFV À1Þ<1yields the same portion of parameter space.Thus,q ðFV À1Þis a threshold parameter in both cases.The difference between the numbers lies in the epidemiological interpretation rather than the mathematical analysis.For example,in column (a),the infection rate is b 1þpr 2and an exposed individual is expected to spend m =ððd þm þr 1Þðd þr 2ÞÞtime units in compartment I .However,this reasoning is biologically flawed since treatment failure does not give rise to a newly infected individual.Table 1Decomposition of f leading to alternative thresholds(a)(b)Fb 1SI =N þb 2TI =N þpr 2I 0000B B @1C C A b 1SI =N þb 2TI =N þpr 2I m E 000B B @1C C A Vðd þm þr 1ÞE Àm E þðd þr 2ÞI Àb ðN ÞþdS þb 1SI =N dT Àr 1E Àqr 2I þb 2TI =N 0B B @1C C A ðd þm þr 1ÞE ðd þr 2ÞI Àb ðN ÞþdS þb 1SI =N dT Àr 1E Àqr 2I þb 2TI =N 0B B @1C C A F0b 1þpr 200 0b 1þpr 2m 0 V d þm þr 10Àm d þr 2d þm þr 100d þr 2 q (FV À1)b 1m þpr 2mðd þm þr 1Þðd þr 2Þffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffib 1m þpr 2mðd þm þr 1Þðd þr 2Þs 36P.van den Driessche,J.Watmough /Mathematical Biosciences 180(2002)29–484.2.Multigroup modelIn the epidemiological literature,the term‘multigroup’usually refers to the division of a het-erogeneous population into several homogeneous groups based on individual behaviour(e.g., [14]).Each group is then subdivided into epidemiological compartments.The majority of mul-tigroup models in the literature are used for sexually transmitted diseases,such as HIV/AIDS or gonorrhea,where behaviour is an important factor in the probability of contracting the disease [7,8,14,15].As an example,we use an m-group SIRS-vaccination model of Hethcote[7,14]with a generalized incidence term.The sample model includes several SI multigroup models of HIV/ AIDS as special cases[8,15].The model equations are as follows:_I i ¼X mj¼1b ijðxÞS i I jÀðd iþc iþ iÞI i;ð7aÞ_S i ¼ð1Àp iÞb iÀðd iþh iÞS iþr i R iÀX mj¼1b ijðxÞS i I j;ð7bÞ_Ri¼p i b iþc i I iþh i S iÀðd iþr iÞR i;ð7cÞfor i¼1;...;m,where x¼ðI1;...;I m;S1;...;S m;R1;...;R mÞt.Susceptible and removed individu-als die at the rate d i>0,whereas infected individuals die at the faster rate d iþ i.Infected in-dividuals recover with temporary immunity from re-infection at the rate c i,and immunity lasts an expected1=r i time units.All newborns are susceptible,and a constant fraction b i are born into each group.A fraction p i of newborns are vaccinated at birth.Thereafter,susceptible individuals are vaccinated at the rate h i.The incidence,b ijðxÞdepends on individual behaviour,which determines the amount of mixing between the different groups(see,e.g.,Jacquez et al.[16]). The DFE for this model isx0¼ð0;...;0;S01;...;S0m;R01;...;R0mÞt;whereS0 i ¼b i d ið1Àp iÞþr iðÞd iðd iþh iþr iÞ;R0 i ¼b iðh iþd i p iÞd iðd iþh iþr iÞ:Linearizing(7a)about x¼x0givesF¼S0i b ijðx0ÞÂÃandV¼½ðd iþc iþ iÞd ij ;where d ij is one if i¼j,but zero otherwise.Thus,FVÀ1¼S0i b ijðx0Þ=ðd iÂþc iþ iÞÃ:P.van den Driessche,J.Watmough/Mathematical Biosciences180(2002)29–4837For the special case with b ij separable,that is,b ijðxÞ¼a iðxÞk jðxÞ,F has rank one,and the basic reproduction number isR0¼X mi¼1S0ia iðx0Þk iðx0Þd iþc iþ i:ð8ÞThat is,the basic reproduction number of the disease is the sum of the‘reproduction numbers’for each group.4.3.Staged progression modelThe staged progression model[11,Section3and Appendix B]has a single uninfected com-partment,and infected individuals progress through several stages of the disease with changing infectivity.The model is applicable to many diseases,particularly HIV/AIDS,where transmission probabilities vary as the viral load in an infected individual changes.The model equations are as follows(see Fig.2):_I 1¼X mÀ1k¼1b k SI k=NÀðm1þd1ÞI1;ð9aÞ_Ii¼m iÀ1I iÀ1Àðm iþd iÞI i;i¼2;...;mÀ1;ð9bÞ_Im¼m mÀ1I mÀ1Àd m I m;ð9cÞ_S¼bÀbSÀX mÀ1k¼1b k SI k=N:ð9dÞThe model assumes standard incidence,death rates d i>0in each infectious stage,and thefinal stage has a zero infectivity due to morbidity.Infected individuals spend,on average,1=m i time units in stage i.The unique DFE has I i¼0,i¼1;...;m and S¼1.For simplicity,define m m¼0. Then F¼½F ij and V¼½V ij ,whereF ij¼b j i¼1;j6mÀ1;0otherwise;&ð10ÞV ij¼m iþd i j¼i;Àm j i¼1þj;0otherwise:8<:ð11ÞLet a ij be the(i;j)entry of VÀ1.Thena ij¼0i<j;1=ðm iþd iÞi¼j;Q iÀ1k¼jm kQ ik¼jðm kþd kÞj<i:8>>><>>>:ð12ÞThus,R0¼b1m1þd1þb2m1ðm1þd1Þðm2þd2Þþb3m1m2ðm1þd1Þðm2þd2Þðm3þd3ÞþÁÁÁþb mÀ1m1...m mÀ2ðm1þd1Þ...ðm mÀ1þd mÀ1Þ:ð13ÞThe i th term in R0represents the number of new infections produced by a typical individual during the time it spends in the i th infectious stage.More specifically,m iÀ1=ðm iÀ1þd iÀ1Þis the fraction of individuals reaching stage iÀ1that progress to stage i,and1=ðm iþd iÞis the average time an individual entering stage i spends in stage i.Hence,the i th term in R0is the product of the infectivity of individuals in stage i,the fraction of initially infected individuals surviving at least to stage i,and the average infectious period of an individual in stage i.4.4.Multistrain modelThe recent emergence of resistant viral and bacterial strains,and the effect of treatment on their proliferation is becoming increasingly important[12,13].One framework for studying such sys-tems is the multistrain model shown in Fig.3,which is a caricature of the more detailed treatment model of Castillo-Chavez and Feng[12,Section2]for tuberculosis and the coupled two-strain vector–host model of Feng and Velasco-Hern a ndez[17]for Dengue fever.The model has only a single susceptible compartment,but has two infectious compartments corresponding to the two infectious agents.Each strain is modelled as a simple SIS system.However,strain one may ‘super-infect’an individual infected with strain two,giving rise to a new infection incompartment。
On Sequential Monte Carlo Sampling Methods for Bayesian Filtering
methods, see (Akashi et al., 1975)(Handschin et. al, 1969)(Handschin 1970)(Zaritskii et al., 1975). Possibly owing to the severe computational limitations of the time these Monte Carlo algorithms have been largely neglected until recently. In the late 80’s, massive increases in computational power allowed the rebirth of numerical integration methods for Bayesian filtering (Kitagawa 1987). Current research has now focused on MC integration methods, which have the great advantage of not being subject to the assumption of linearity or Gaussianity in the model, and relevant work includes (M¨ uller 1992)(West, 1993)(Gordon et al., 1993)(Kong et al., 1994)(Liu et al., 1998). The main objective of this article is to include in a unified framework many old and more recent algorithms proposed independently in a number of applied science areas. Both (Liu et al., 1998) and (Doucet, 1997) (Doucet, 1998) underline the central rˆ ole of sequential importance sampling in Bayesian filtering. However, contrary to (Liu et al., 1998) which emphasizes the use of hybrid schemes combining elements of importance sampling with Markov Chain Monte Carlo (MCMC), we focus here on computationally cheaper alternatives. We describe also how it is possible to improve current existing methods via Rao-Blackwellisation for a useful class of dynamic models. Finally, we show how to extend these methods to compute the prediction and fixed-interval smoothing distributions as well as the likelihood. The paper is organised as follows. In section 2, we briefly review the Bayesian filtering problem and classical Bayesian importance sampling is proposed for its solution. We then present a sequential version of this method which allows us to obtain a general recursive MC filter: the sequential importance sampling (SIS) filter. Under a criterion of minimum conditional variance of the importance weights, we obtain the optimal importance function for this method. Unfortunately, for numerous models of applied interest the optimal importance function leads to non-analytic importance weights, and hence we propose several suboptimal distributions and show how to obtain as special cases many of the algorithms presented in the literature. Firstly we consider local linearisation methods of either the state space model 3
斑马鱼心血管疾病模型研究进展
·综述·斑马鱼心血管疾病模型研究进展董顺雨 张 态大理大学公共卫生学院（云南大理 671000）【摘 要】 心血管疾病是导致我国居民死亡的首要原因。
在2006—2019年间，我国每年因心血管疾病死亡的人数从215万人增加到328万人。
斑马鱼因个体小、成本低廉、体外发育、身体透明、基因组与人类高度同源等特点，近年来被广泛应用于医学研究。
斑马鱼模型有利于推动心血管疾病领域的基础性研究。
该文通过对前期研究进行综述，重点介绍了斑马鱼模型在心血管疾病中基因筛选、心脏再生、药物筛选、毒性评估等方面的研究进展。
【关键词】 斑马鱼；心血管疾病；心脏再生；药物筛选；毒性评估DOI ：10. 3969 / j. issn. 1000-8535. 2024. 03. 003Research progress of zebrafish cardiovascular disease modelsDONG Shunyu ，ZHANG TaiSchool of Public Health ，Dali University ，Dali 671000，China【Abstract 】 Cardiovascular disease is the leading cause of death in China ．Between 2006 and 2019，the annual number of deaths due to cardiovascular diseases increased from 2.15 million to 3.28 million ．Zebrafish has been widely used in medical research in recent years because of its small individual size ，low cost ，in vitro development ，transparent body and high homology of genome with human ．The zebrafish model is conducive to promoting basic research in the field of cardiovascular disease ．Based on the review of previous studies ，this paper focuses on the research progress of zebrafish model in gene screening ，cardiac regeneration ，drug screening ，toxicity assessment and other aspects of cardiovascular diseases ．【Key words 】 zebrafish ；cardiovascular disease ；heart regeneration ；drug screening ；toxicity assessment基金项目：中国西南药用昆虫及蛛形类资源开发利用协同创新中心（CIC1803）通信作者：张态，E-mail:******************心血管疾病是全球的主要死亡原因，是由环境因素和遗传因素共同导致的一种疾病［1］。
分级词表 中英对应
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部分泛素特异性蛋白酶生物学功能的研究进展
部分泛素特异性蛋白酶生物学功能的研究进展*杨静① 张丽璇② 张晨钰③ 安康③ 【摘要】 泛素特异性蛋白酶（ubiquitin-specific proteases，USPs）家族是去泛素化酶家族中成员最多的一种，主要存在于骨骼肌、心脏、肝脏、脑、胰腺等组织中，且在不同物种间有表达差异性。
目前的研究表明，虽然USPs特异性选择水解的泛素链的机制还不清楚，但USPs在机体生命过程中有极大作用，USPs在调控肿瘤发生及转移、免疫调节、炎症反应、能量代谢、病毒感染等方面具有重要临床意义。
本文综述了近年来部分USPs生物学功能的研究进展，期望能够对相关疾病的诊断及治疗提供新的思路。
【关键词】 泛素特异性蛋白酶 肿瘤 治疗靶点 Research Progress in Biological Functions of Partial Ubiquitin-specific Proteases/YANG Jing, ZHANG Lixuan, ZHANG Chenyu, AN Kang. //Medical Innovation of China, 2024, 21(01): 149-154 [Abstract] The family of ubiquitin-specific proteases (USPs) is the most abundant member of the deubiquitinating enzyme family, different and is mainly present in skeletal muscle, heart, liver, brain, pancreas and other tissues, with differential expression among different species. Current studies have shown that the USPs has a great role in organismal life processes, although the mechanism by which the USPs specifically selects ubiquitin chains for hydrolysis is not clear. USPs have important clinical significances in the regulation of tumorigenesis and metastasis, immune regulation, inflammatory response, energy metabolism and viral infection. In this paper, we review reserch progress on biological functions of partial USPs in recent years, expecting to provide new ideas for the diagnosis and treatment of related diseases. [Key words] Ubiquitin-specific proteases Tumors Therapeutic target First-author's address: Basic Medical College of Hebei North University, Zhangjiakou 075000, China doi：10.3969/j.issn.1674-4985.2024.01.036 泛素特异性蛋白酶（USPs）家族是最大的一类去泛素化酶，包含56个成员，该家族中的部分成员已被证实与肿瘤的发生与发展具有重要关系[1]。
IpsconfususandIpsparaconfusus
EPPO quarantine pest Prepared by CABI and EPPO for the EUunder Contract 90/399003Data Sheets on Quarantine PestsIps confusus and Ips paraconfususIDENTITYTaxonomic position: Insecta: Coleoptera: ScolytidaeNotes on taxonomy and nomenclature: Although the quarantine pest which appears in the EPPO and EU lists is named as I. confusus, Furniss & Carolin (1977) explain that this species, the piñon ips, has in the past been confused with the very similar I. paraconfusus, the California five-spined ips. The former is confined to pinyon pines, while the latter occurs on all pine species within its range, especially P. ponderosa. For this reason, it seems evident that the intended quarantine pest, originally listed in the 1970s, must have been I. paraconfusus at least as much as I. confusus. Both species are therefore covered in this sheet. With their range in western USA, they belong to the same group as the very similar sibling species I. grandicollis (southeastern USA and Caribbean) and I. lecontei (Arizona and Mexico) (EPPO/CABI, 1996).• Ips confususName: Ips confusus (LeConte)Synonyms: Tomicus confusus (LeConte)Common names: Piñon ips (English)Bayer computer code: IPSXCOEPPO A1 list: No. 271EU Annex designation: II/A1 - under non-European Scolytidae• Ips paraconfususName: Ips paraconfusus LanierCommon names: California five-spined engraver, California five-spined ips (English) Bayer computer code: IPSXPAEU Annex designation: II/A1 - under non-European ScolytidaeHOSTSI. confusus attacks the pinyon pines Pinus edulis and P. monophylla, and rarely other Pinus spp., while I. paraconfusus attacks the timber species P. ponderosa, P. attenuata, P. contorta, P. coulteri, P. lambertiana, P. monticola, P. muricata, P. radiata and P. sabiniana. According to Cane et al. (1990), female I. confusus are attracted specifically to pinyon pines on which males have aggregated, while male I. confusus and both sexes of I. paraconfusus are not specifically attracted to individual pine species. GEOGRAPHICAL DISTRIBUTION• Ips confususEPPO region: Absent.North America: Mexico, southwestern USA (Arizona, California, Colorado, Nevada, New Mexico, Oregon, Texas, Utah, Wyoming).EU: Absent.• Ips paraconfususEPPO region: Absent.North America: USA (California, Oregon).EU: Absent.BIOLOGYThere is little specific information available about I. confusus or I. paraconfusus and the following account relates to North American Ips spp. in general. Adults and larvae are phloeophagous or bark-feeding, mainly attacking declining or dead trees and freshly cut wood. They frequently carry the spores of bluestain fungi. They usually overwinter in the adult and larval stage with the proportion of adults to larvae varying from species to species (Wood, 1982).Adults emerge from overwintering sites between February and June. Activity is resumed when subcortical temperatures become sufficiently high, about 7-10°C. The insects fly individually or in small groups, during the warmth of the day in spring or near nightfall in summer (at temperatures between 20 and 45°C), and infest further trees. Terpenes in the oleoresin are the primary source of attraction, guiding pioneer beetles in the selection of a new host. Pheromones are responsible for the secondary attraction of other members of the same species and are the means by which individuals communicate after colonization.Ips spp. are polygamous: the male excavates the entrance tunnel and nuptial chamber, and then admits two to five females. The females push their frass into the nuptial chamber. The male has the responsibility for ejecting their frass and for protecting the entrance hole. The eggs are usually deposited in individual niches, contiguous in I. confusus. There are three larval instars (Wilkinson, 1963). The length of the larval period under optimum conditions is, as in other scolytids, 30-90 days. The end of the larval mine is usually slightly enlarged and cleared of frass to form a pupal chamber. The pupal stage, as in other scolytids, requires 3-30 days, but averages 6-9 days under ideal conditions. It may be extended if pupation begins in late autumn, but is rarely an overwintering stage except in areas where the winters are very mild.The adult beetles may emerge from the host tree immediately, even before becoming fully coloured, or may require a period of maturation feeding before emerging. After completing one gallery system it is not uncommon for the parent beetles to re-emerge and construct a second, third or fourth system of tunnels to produce an equal number of broods.A few old adults may survive the winter and participate in the production of the spring brood.I. confusus has three or sometimes four annual generations. I. paraconfusus typically has two summer generations in fallen logs and an overwintering generation in standing trees. In the southern part of its range, there may be 3-5 summer generations. DETECTION AND IDENTIFICATIONSymptomsIn Ips spp., the gallery system is situated in the phloem-cambial region and consists of a central nuptial chamber from which elongate egg galleries fork or radiate, forming a species-diagnostic pattern. In I. paraconfusus, the egg galleries comprise 3-5 nearly straight tunnels radiating from the entrance chamber. The typical pattern has three galleries in an inverted "Y" pattern.The larval galleries commence more or less parallel to or divergent from the egg gallery, penetrating the bark or wood to varying depths and progressively widening awayfrom it. These galleries are usually full of debris. The gallery terminates in a small chamber, where pupation occurs and the adult emerges through a hole from this chamber. Larval mines are always visible on peeled bark.MorphologyEggsSmooth, oval, white, translucent.LarvaWhite, legless, with lightly sclerotized head; head usually as broad as long with evenly curved sides, protracted or slightly retracted; frons sometimes with pair of tubercles (some Ips spp.). Body at most only slightly curved; abdominal segments each with two or three tergal folds; pleuron not longitudinally divided. Larvae do not change appreciably in form as they grow. For generic keys to the larvae of Ips and other bark beetles, see Thomas (1957).PupaThe pupae of scolytids are less well known than the larva: exarate; usually whitish; sometimes with paired abdominal urogomphi; elytra rugose or smooth; head and thoracic tubercles sometimes prominent.AdultIn general, Ips adults are small, 0.5-8 mm in length (3.0-5.5 mm in I. confusus), cylindrical to hemispherical in form, usually yellow, brown or black, sometimes shining and glabrous, dull and coarsely granulate, densely pubescent or covered with scales. Antennae geniculate, funicle five-segmented, with abrupt three-segmented club; subcircular to oval, strongly flattened, with sutures strongly to moderately bisinuate. Head partly concealed in dorsal view, not prolonged into distinct rostrum, narrower than pronotum, with mouthparts directed downwards. Eyes flat, usually elongate, sometimes notched, very rarely rounded or divided. Pronotum weakly to strongly declivous anteriorly and usually with many asperate crenulations in anterior half. Scutellum large and flat. Elytra entire, concealing pygidium, with basal margin straight and without crenulations. Elytra terminate in a rounded or blunt slope (the declivity) which is concavely excavated with lateral margins dentate, all teeth on summit (I. confusus and I. paraconfusus belong to a group with 5 spines on the elytral declivity). Tibiae unguiculate. Tarsal segment 1 not longer than 2 or 3, distinctly five-segmented. For generic and specific keys to Ips and other genera, see Wood (1982). I. confusus and I. paraconfusus closely resemble each other morphologically.I. confusus and I. paraconfusus can be distinguished from each other and from other members of the Ips grandicollis group (I. grandicollis,I. lecontei and others) by the random amplified polymorphic DNA (RAPD) technique, which yielded a diagnostic DNA banding pattern for each species (Cognato et al., 1995).MEANS OF MOVEMENT AND DISPERSALSome bark beetles are strong fliers with the ability to migrate long distances. The most common mode of introduction into new areas is unseasoned sawn wood and wooden crates with bark on them. If wood is barked, there is no possibility of introducing bark beetles. Dunnage is also a high-hazard category of material, on which most of the scolytids intercepted in the USA are found. It is particularly difficult to monitor properly.PEST SIGNIFICANCEEconomic impactLike other scolytids, Ips spp. periodically cause loss of wood (cut wood and sometimes standing trees) over extensive areas. Their galleries do not affect the structural properties ofthe wood significantly, but may render it useless for veneer or furniture making. However, they tend to be less aggressive and less host-specific than Dendroctonus spp.They mostly breed in slash, or in broken, fallen or dying trees. In this way, I. confusus can kill pinyon pines in southwest USA, when outbreaks start on trees that are damaged or uprooted in land-clearance schemes (Furniss & Carolin, 1977). I. paraconfusus is of greater practical importance because it attacks the timber tree P. ponderosa, killing saplings and young trees up to about 65 cm in diameter. Outbreaks develop on recently cut wood and spread to nearby living trees. This is reflected by a much greater number of publications on I. paraconfusus than on I. confusus. Top-killing by I. paraconfusus can contribute to outbreaks of the more dangerous pest Dendroctonus brevicomis (EPPO/CABI, 1996).I. paraconfusus is also one of the possible vectors of Fusarium subglutinans f.sp. pini, the pathogen of pine pitch canker, a disease which is increasing in importance in California (Storer et al., 1994).ControlBroadly, the same control methods are available for all bark beetles. A tree that has been attacked usually cannot be saved, so preventive rather than curative control is best. Since scolytid populations are probably always present in a forest, breeding on unthrifty, injured, broken, wind-thrown or felled material, damage can be reduced or avoided by maintaining the health and vigour of the stand; especially by thinning stagnated young stands or removal of overmature trees in older stands.Losses caused by bark beetles usually involve individual trees or irregularly distributed groups of trees. Insect surveys are made to locate and appraise infestations in their early stages. If endemic conditions prevail, natural control factors (climate, weather, predators, parasites, disease) will hold the population at a steady level at which damage is within normal limits (losses less than annual tree growth). If epidemic conditions exist, damage exceeds normal limits (losses exceed annual growth). Such surveys determine the need for direct control. The available methods have been reviewed in EPPO/CABI (1992). Treatment with insecticides is used, if at all, for logs rather than for trees. Phytosanitary riskI. confusus is an A1 quarantine pest for EPPO, within the category "non-European Scolytidae" (EPPO/CABI, 1992); it may be that this A1 entry was based in part, or mostly, on the risk presented by I. paraconfusus. For I. confusus in the strict sense, the risk for the EPPO region can be assessed as practically negligible, since this species is a secondary pest of pinyon pines only, in a specific montane environment in southwestern USA. I. paraconfusus can, however, make primary attacks on Pinus spp. and presents a moderately high risk for the EPPO region, since the geographical range of this species in North America (California and southern Oregon) covers climatic conditions which are similar to those of southern Europe and because the main Pinus species concerned in North America is P. ponderosa, which has been widely planted in the EPPO region.Indigenous Ips spp. already occur on conifers throughout most of the EPPO region, so the risk arising from introduced species is uncertain. However, those areas of the EPPO region which lack indigenous Ips spp. and protect themselves from species already present elsewhere in Europe (e.g. I. typographus) have evident reason to protect themselves also from North American pest species of Ips.PHYTOSANITARY MEASURESIf measures are needed against I. paraconfusus, those recommended for I. pini (EPPO/CABI, 1996) should also exclude it.BIBLIOGRAPHYCane, J.H.; Wood, D.L.; Fox, J.W. (1990) Ancestral semiochemical attraction persists for adjoining populations of sibling Ips bark beetles. Journal of Chemical Ecology16, 993-1013.Cognato, A.I.; Rogers, S.O.; Teale, S.A. (1995) Species diagnosis and phylogeny of the Ips grandicollis group (Coleoptera: Scolytidae) using random amplified polymorphic DNA. Annals of the Entomological Society of America 88, 397-405.EPPO/CABI (1992) Scolytidae (non-European). In: Quarantine pests for Europe (Ed. by Smith, I.M.;McNamara, D.G.; Scott, P.R.; Harris, K.M.). CAB International, Wallingford, UK.EPPO/CABI (1996) Ips calligraphus. Ips grandicollis. Ips lecontei. In: Quarantine pests for Europe.2nd edition (Ed. by Smith, I.M.; McNamara, D.G.; Scott, P.R.; Holderness, M.). CAB INTERNATIONAL, Wallingford, UK.Furniss, R.L.; Carolin, V.M. (1977) Western forest insects (Scolytidae, Platypodidae). Miscellaneous Publications, United States Department of Agriculture, Forest Service No. 1339, pp. 1-654. Storer, A.J.; Gordon, T.R.; Dallara, P.L.; Wood, D.L. (1994) Pitch canker kills pines, spreads to new species and regions. California Agriculture48, 9-13.Thomas, J.B. (1957) The use of larval anatomy in the study of bark beetles (Coleoptera: Scolytidae).Canadian Entomologist, Supplement5, 3-45.Wilkinson, R.C. (1963) Larval instars and head capsule morphology in three southeastern Ips bark beetles. Florida Entomologist46, 19-22.Wood, S.L. (1982) The bark and ambrosia beetles of North and Central America (Coleoptera: Scolytidae), a taxonomic monograph. Great Basin Naturalist Memoirs6, 1-1359.。
Sounds of Planet EXs 177 Saxophones for Kronos 商品说
© 2012-2018 by SOP - All Rights Reserved This document is protected by EU copyright andother intellectual property laws and may not be reproduced, rewritten, distributed, re-disseminated, transmitted, displayed, published or broadcast, directly or indirectly, in any medium without the prior written permission of SoP.Executive Producer/Editor: Grzegorz MarciakSounds of Planet would like to thank you for purchase of sound set called EXs 177 Saxophones for Kronos.Sounds of Planet prepared the sound library EXs 177 Saxophones.This is the library, which offers the highest quality samples of extraordinary instruments, as the saxophones are, and more :- alto saxophone – two different instruments were recorded by two various musicians,- tenor saxophone - two different instruments were recorded by two various musicians,- soprano saxophone- baritone saxophone- trumpetAll samples have been processed in 24-bit technology at 48000 Hz.Ex’s 177 Saxophone s from Sounds of Planet offers the set of sounds consisting of- 128 programs- 32 wave sequences- 393 MB multisamplesSaxophone came into existence in Belgium and its artificer was Antoine Joseph Sax known as Adolphe, who was born era of Napoleon and Beethoven. He was fascinated by the way, in which from ordinary piece of metal the real music is born. He created an instrument, which until today has been fascinating for people and has so irresistible charm. Mr. Sax created the instrument, which allows to freely shape the tone and pitch of the sound, from gentle whisper to loud scream and anything in between. Saxophone combines the best features of orchestral instruments . It has quickly turned out that , that this instrument fits into any kind of music and because of that it has been so popular until now. Programs of EXs 177 Saxophones require the factory preload sounds.Make a copy of all own files in the instrument performing SAVE ALL function- see manualKRONOS_Quick_Starts or KRONOS_Param_Guide.The following instructions are copied from the Kronos Parameter Guide for your convenience:To install an EX s:1. If you downloaded the EXs data, un‐zip the downloaded file. Un‐zipping thearchive will result in a folder containing several different files. Note: Depending on yourbrowser settings, the downloaded file may be unzipped automatically. One of the files in theresulting folder has a name which ends with “tar.gz.” Please do not un‐zip this tar.gz file.2. Copy the un‐zipped folder to a USB storage device.3. Safely disconnect the USB storage device from your computer.4. Connect the USB storage device to the KRONOS.5. Go to the Disk Utility page.6. Using the Drive Select menu at the bottom of the page, select the USB storagedevice. You may need to wait a few seconds after connecting the device before it isrecognized.7. Open the folder containing the EXs data from step 2.8. Select the file whose name ends in .exsins. The “exsins” suffix stands for “EXSIns taller.” For instance, an installer file might be named “EXs177.exsins.” When an .exsins fileis selected, the Load button changes to read Install. Only one EX s can be installed at a time.If Multiple Select is On, Install will be disabled.9. Select Install EXs from the menu, or press the Install button. The system will checkto confirm that the installation files are valid, and that there is sufficient space on the SSD to install the EX s. Next, a dialog box will appear:Found installer for: [EX s name]Space required: [nnn] MBSSD1: [disk name] [nnn] GB available10. Press Install to continue with the installation, or press Cancel to stop without installing. An “are you sure?” message will appear to confirm the installation.11. Press OK to continue with the installation, or press Cancel to stop withoutinstalling. The installation will then begin. This may take a while; a progress bar shows the installation as it proceeds. Next, the newly installed files will be verified. After the verification has completed successfully, the progress bar will disappear, and the installation is complete. The EX s sample data itself is installed on an invisible, protected part of the disk. To use the EX s, you’ll lo ad its associated files (.KSC, PCG etc.); for the location of these files, see the documentation of the specific EX s.Using the newly installed EXsTo use the new EX s:1. Load the newly installed .PCG and .KSC files. Make sure to back up any sounds before over‐writing them in memory.As default, programs EXs177 Saxophone will load to the bank U-FF.Programs of EXs 177 Saxophones require the factory preload sounds.Global “0–3: KSC Auto‐Load”Global “0–4: Sample Management”Disk mode menu command “Load .PCG”Disk mode menu command “Load .KSC”AuthorizationIf an authorization code is required, the EX s will work in demo mode, fading in and out, until the code is purchased and entered into the KRONOS. For more information, see “Global P6: Options Info”.New programs are installed in bank U-FF. Program & Multisample List:Short description of abbreviations used in name of programs reflecting the nature or type of sound :FF (fortissimo) very loud – for example : Alto FFMF (mezzo forte) medium loud - for example : Alto MFPP (pianissimo) very quietly - for example : Alto PPOther examples of used abbreviations:Alto 1 Layer (-Y)Growl P – “P ” on the end means PolyAlto 1 Layer (-Y)Growl M – “M ” on the end means MonoNew WaveSequence are installed in bank U-FF.The following instructions are copied from the Kronos Parameter Guide for your convenience:Uninstall EXsOptional EXs may be uninstalled to reclaim space on the internal disk(s). To do so:1. Go to the Global P6: Options Info page.2. In the list of Installed Options, select the EXs thatyou’d like to remove.3. Select the Uninstall EXs command from the menu.A dialog box will appear: Uninstall [EXs name and number]Delete all of the option’s EXs Samples and Multisamples?4. Press OK to continue. Another dialog box will appear, showing that the uninstall isin progress. After the uninstall is complete, a third dialog box will appear:[EXs name and number] sample data deleted.Related PCG, KSC etc. may remain; delete manually if desired. Only the EXs Multisamples and Drum Samples are removed from the disk. KSC and PCG files can be edited, and so they might contain your personal data; to avoid inadvertently affecting your data, these files are left untouched.5. Press OK to continue.6. If you like, delete the related PCG and KSC filesmanually in Disk mode.。
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本份文档包含该专题的：外文文献、文献综述一、外文文献Transport, Logistics, and Fulfillment OptionsLaurel J. DelaneyAir TransportShipping by air used to be an emergency strategy, used only when a customer needed a product immediately, but with the proliferation of international air delivery services such as Federal Express, DHL, UPS, and Airborne Express, it is now easy and economical to move your product around the world, even overnight. You’ll generally pay a higher price per kilo than you will for ocean shipment, but in some expense categories you’ll actually rack up some savings. For example, packing costs tend to run less for air transport. One major consideration is the weight of your cargo. Are you exporting feathers? If so, air transport would be cheaper, provided you don’t use cartons that take up a lot of space. Tractors, on the other hand, should be transported via ocean.If exporting highly perishable items is your business, you’ll want to familiarize yourself with carriers that offer affordable worldwide express shipments of chilled, frozen, and fresh foods, such as seafood, meats, and produce. You will see more and more demand for this service as the market for organic, fresh, and convenience foods expands. I suggest you call the US Department of Agriculture’s internat ional marketing office for additional help. It usually has directories, workbooks, and guides to assist exporters of highly perishable products.The International Air Transport Association represents 240 airlines worldwide. When these members reach agreement on a fixed rate, they file a tariff with the US Department of Transportation. Tariffs define the rate, rules, and regulations governing air cargo deliveries for a given carrier or conference. Only when an exporter is charged by a shipper a cost that is beyond the maximum amount specified in the tariff (unless it is under a service contract) will she need to notify a regulatory agency to complain.There are two major types of equipment used in air transport:1. Air cargo containers: These types of containers are loaded by hand or forklift. They come in more than a dozen different styles and sizes.2. Air cargo pallets made of wood or plastic (corrugated plastic is used but not recommended) with netting: These are also loaded by hand or forklift.Which type of equipment you use depends on the type and quantity of the cargo you are shipping. To determine the absolute best way to ship your cargo, always discuss your situation with your transportation company. And don’t forget to find out the distance from your customer’s door to the closest seaport or airport. If one delivery destination is closer than the other, you’ll save your customer time but not necessarily money in the case of shipping to the nearest airport, because air cargo can be expensive.The top two considerations when choosing air vs. sea freight are transit time and the cargo itself. It usually takes a product a couple of days to arrive by air, whereas sea freight takes anywhere from twelve to fourteen days. The cargo itself, whetherdelicate in nature (fine art, for example) or large in size (as is heavy equipment), forces you to make the best decision for your cargo shipment.CautionAlways check with your shipping specialist to verify the pallet requirements for your destination country. Some countries, for example, require certain types of wood packaging to be treated with chemicals or heat before being allowed into their country.Ocean TransportShipping by ocean takes much longer than shipping by air, but it is nearly always much less expensive. That is why it will generally be your overseas customers’ preferred method of transport. Whereas with air shipment, the greater the volume of your shipment, the more expensive it becomes, with ocean shipment a greater volume of shipment actually decreases the cost. Ocean transport is less simple, though, because it involves many more choices that you may know very little about. These include the choice between terminals, vessel types, container loading options, and so forth. You’ll have to rely on your transport company to give you advice.When choosing a transport company, you’ll want to find out the following:1. The frequency that the vessels sail2. The transit times3. The reliability measures4. The ports served by steamship line5. The company’s safety record6.The computerization for cargo managementThe last point, computerized cargo management, is vital these days. You want to be able to track your cargo at any given point. If it gets lost, you want to know that the transport company can find it. Cargo management is an important part of the package you offer your customers—so anytime you find a new and better way to serve them in terms of cargo, jump on it.Shopping for an Economical Transport PackageShipping lines—whose vessels are still commonly referred to as “steamships” although the days of steam-powered shipping are long gone—can be classified as either independent or conference. Independent lines tend not to have as many ports of call, which can cause shipping delays. Sometimes, while comparison shopping, you will find an independent line that quotes you a rate that is cheaper than what the conference lines are offering. Howe ver, when using an independent line you can’t be sure of your shipper’s timeliness or reliability.Conference lines, on the other hand, guarantee similar standards and rates. If you can contract with a conference line on an exclusive basis, rates are usually cheaper than, or at least competitive with, those offered by an independent line. The guarantee on rates during a specified period of time is a savings that you can then pass on to your customer or use to pad your own profit margin. Other types of ocean transport companies that have evolved over the years are NVOCCs, or non-vessel-operating common carriers, and shipper’s associations. NVOCCs book space on vessels and then sell the space to shippers with smaller cargoes in smaller-volume units. They consolidate these smaller shipments into container-loads under one bill of lading, andas a result can pass on more favorable rates to the small cargo shipper. You can also take advantage of a larger shipper’s economies of scale to move your smaller loads more cheaply. Shipper’s associations, similarly, were formed to pull together several different shippers’ cargoes to achieve greater volume and hence lower rates.Don’t forget that ocean and air shipping itself is only part of the transport package you’ll need to assemble. To get your product to an ocean-going vessel for loading, you must also transport your cargo overland by truck or rail. How do you do this without spending an arm and a leg? The most advanced and efficient transport mode currently available to exporters to handle this problem is intermodal transportation. This is a start-to-finish transport package that takes your cargo from its point of origin to its point of destination (commonly described as “door-to-door”) under a single bill of lading. It involves the use of at least two different transportation modes—rail and ocean, for example—to cover the overland and overseas movement of the cargo. The company that offers the package is liable for getting the cargo from the point of origin to the final destination, and it will charge you a “through rate” to do so. The rate represents a substantial savings over what it would cost you to engage separate carriers for each leg of the trip. An added bonus: The company can issue a computer-generated bill of la ding within hours of the cargo’s receipt at an inland terminal or immediately after the vessel has left port. This means faster turnaround time in collecting payment from your customer. Some intermodal service packages also offer container freight stations, which save you time and drayage (local transportation) costs by bringing their service closer to your door.TipWith the Internet and the advent of e-commerce sales transactions for B-to-C transactions, most international carriers and third-party logistics providers now offer all-inclusive door-to-door landed costs (meaning they include the price of the product, the delivery charge, taxes, duties, customs, and in a currency your shoppers understand) on single-product shipments delivered to a consumer. In 2009, this was unheard of. What a difference five years makes!If you are an exporter of refrigerated commodities, most sophisticated transportation companies can offer cost-efficient transport via refrigerated vehicles. For example, there are railcars equipped with individual generators to ensure the preservation of perishable products during transit. Some companies offer what is called a “motorbridge” (trucking) service to exporters of frozen meat and other perishables, which entails a through transportation rate from the producer’s door to the customer’s door. Other companies offer multipurpose vessels for more cost-effective shipment of noncontainerized cargo, such as tin, tea, equipment, and grain. These vessels are usually smaller in size than those found in a regular containerized ship, allowing them to travel safely through rough seas and narrow channels. They also make the difficult portside dockings at newly industrialized countries easier.It’s imperative to shop around and compare rates to get the best-possible transportation package for your customer. Don’t be shy about questioning a transportation company or freight forwarder at length and in great detail about its service and rates. That is what it is there for, and you don’t owe them anything untilafter you’ve hired them. Always inquire about the latest and most advanced methods for moving goods overseas. Even as you read this, improvements are underway. Keeping current with the transportation industry will help you offer your customers the most innovative and cost-effective service and equipment options.Break-Bulk and Container LoadingWhat kind of vessel you choose to ship your cargo, and what special handling, loading or storage apparatus, if any, should be used, will depend on the type and quantity of your goods. Here are a variety of common options and techniques for loading your shipment.Break-BulkBetter known as less–than–container-load, or LTL shipment, break-bulk shipment is the most likely option to be used by new exporters, whose first orders are likely to be small. It allows your customer to test the product in his market before committing to a large quantity, such as a full container-load or more. The shipper can still load the goods into a container, but the container will be delivered to a consolidation point (port of exit) where other shippers’ goods will also be stowed in the container. The advantage of this method is that it allows smaller, low-volume exporters to have their cargo containerized, although it is not as desirable as a sealed door-to-door container, as I will discuss.To control the expense of small-quantity shipment, find a transport company that specializes in break-bulk. Naturally, when you are shipping a small trial order and hoping for repeat business, it will be to your advantage to control your customer’s costs by offering them the best rate possible. When shipping LT L, you’ll need to take extra care in packing and marking your cartons. (I’ll discuss carton marking in greater detail later.) Break-bulk shipments are commonly packed using the following materials:Pallets: Wood pallets must be strong enough to be stacked on racks and reused numerous times.Never let your cartons overhang a pallet. Your whole load might collapse! As previously mentioned, some countries require certain types of wood pallets to be treated with chemicals or heat before allowing the shipment to cross its borders. Check with your transportation specialist.Slipsheets: Used to pull your cargo to the point of loading, these sheets are usually made of fiberboard or plastic. They must be strong enough for the forklift operator to clamp onto and pull. Slipsheets cost less than pallets and eliminate the expense of transporting pallets back to the shipper for reuse. Cartons placed on slipsheets must be cross stacked, shrink-wrapped, or secured with extra-strength strapping.Crates: Wood crates are still popular with some shippers due to their strength and resistance to humidity, at any temperature and at any point in transit.All onboard packing aids should be recyclable or reusable. Use the minimum amount of material necessary to protect your product. Pallets, slipsheets, and crates are loaded using the following methods:Bulk loading by machine or hand (for bulk commodities, for example)Hand loading using individual shipping containers, with or without palletsUnit loading using palleted or slipsheet stacks into containers with forkliftsContainer LoadingShipment by container-load continues to be the preferred method for exporting goods because each container is sealed (allowing it to stay closed from the factory door to the customer’s door), strong, the ft resistant, and stackable. Containers are also easy to load and unload; transport by truck, rail, or ship; and store. The only time the container may be opened while in transit is for the customer’s inspection, so the transport of the goods becomes nearly bulletproof concerning safety and pilferage issues.NoteExporting by container continues to grow. According to trade data produced by PIERS, “U.S. containerized exports were up 5 percent in February 2013 compared to February 2012, reaching 1,011,874 20-foot-equivalent units.” PIERS, a database of US waterborne trade activity, says this is the largest year-over-year increase since June 2012, when exports jumped nearly 10 percent.Containers are available in various volumes and in a number of specialized constructions to accommodate various cargo types. Typically, shipping companies provide containers, but you can also rent or buy them new or used. If you want to do so, try eBay, contact a local shipping company to inquire about used shipping containers, or contact the Container Alliance, a network of portable storage and shipping container providers.A container can cost anywhere from $1,500 (used) to $8,000 (new). Rental costs range from $75 to $295 per month. You can also expect to pay delivery and pickup charges on any of these scenarios. The twenty-foot container, the most popular volume, works well for starting up with exports. The forty-foot container is the second-most popular choice. It’s important to resist the temptation to overload this larger co ntainer or you won’t be able to move your cargo over land! For large loads, a forty-five-foot container is an attractive bargain because it gives you a 27 percent increase in interior capacity over the forty-foot unit for the same handling costs. Containers come as large as forty-eight feet, but these are comparatively rare.Just as you conducted market research on where the best market is for your product using a variety of sources, keeping track of where all your exports are going provides a good basis fo r asking yourself, “Should we be looking at these markets since there are so many containers going to that part of the world?” Take The Journal of Commerce’s annual ranking of the top fifty world container ports for 2012).5 Here is a snapshot of the top ten container ports, which shows heavy concentration in China (Asia):The port of Shanghai handled 32.5 million twenty-foot-equivalent container units, considered the busiest container port in the world in 2012.High-cube containers (referred to as HQ; they include twenty-foot, forty-foot, and other measurements) are oftentimes shipped at the same rate as a standard container but offer more cargo space and are typically one foot taller. Garment containers have a movable track system, so that prepressed and prelabeled garments can be shipped on their individual hangers, unloaded, moved right into a showroom, and racked for sale. Open-top containers, designed for awkward, oversize goods, such as heavy equipment,can be loaded from the top by crane. This reduces handling costs. Refrigerated containers come in high-cube and wide-body dimensions and offer temperature-controlled environments that can be monitored by means of an exterior temperature recorder, a central shipboard control, or even satellite transmission. Bulk-hatch containers, used for commodities such as corn and grains, can be loaded from the top or the rear for easy access and minimal handling. Vented containers allow for appropriate ventilation and thus eliminate potential condensation, preventing damage to moisture-sensitive goods like tobacco, spices, and coffee. Flat-rack containers, designed for moving huge goods, such as heavy equipment, lumber, and pipes, can be loaded from the top or the side, thus reducing handling costs. An expandable chassis accommodates a variety of box sizes and allows for easy offloading from ship, to train, to truck.TipIf you are interested in learning more about shipping containers and who invented containerized cargo (hint: an American by the name of Malcolm P. McLean), read the article “The Truck Driver Who Reinvented Shipping,” and try The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger, by Marc Levinson. Both are fascinating reads!Having shown you what’s entailed in getting your shipment underway, I’d like to introduce you to one of my favorite solutions for the shipping phase: the freight forwarder.The Global Freight Forwarder: Your One-Stop Transport ProGlobal freight forwarders serve as all-around transport agents for moving export cargo, typically transporting it from a factory door to your customer’s warehouse or storage facility. Their service saves you lots of time, effort, and anxiety and is available for a very reasonable fee, usually under US$200 per transaction—an expense that you’ll include in your price quotation to your customer and recoup when you collect payment. These are just some of the things a freight forwarder will do for you:Handle all shipping arrangements on the basis of your specificationsTake legal responsibility for the shipmentPay up-front costs to move the productArrange for a carrier to arrive at your factory door at a specified date and timeBook space with transportation carriersHandle all documentation and see that it is properly processedArrange insurance, if requestedPresent documents to your bank in a timely fashion to meet your payment terms Suggest or make on-the-spot packing adjustments, if neededMove the product from the factory door to the port of exit, either by common carrier or railTake responsibility for getting the cargo on the vessel in time to sail on schedule, thus enabling you to meet all the terms and conditions of your payment agreement Monitor the shipment from beginning to end and keep you informed throughoutSee to it that the shipment arrives safely at the foreign port of entry and proceeds fromthere, depending on the delivery terms that you quoted to your customerIf you were to undertake the transit of goods yourself, you would probably be overwhelmed by all these logistics, and you would certainly not achieve the savings that forwarders can, given the networks of service providers that they have in place and the volume and frequency of shipping that they do. You can find freight forwarders by conducting a web search using the keywords “Freight forwarders, international transportation” or you can check for listings in trade magazines or other international directories. You should find hundreds of them. In some instances, they will be categorized by the geographic area they serve, the type of commodity in which they specialize, or the transport modes they offer, such as air or ocean—most forwarders offer both. Pick two or three that seem like a good fit for your product and shipping destination. Some may be located near your office or by an airport or port facility that you expect to use often.The Kings and Queens of International Shipping: UPS, FedEx, DHL, and TNT Logistic experts UPS, FedEx, DHL, and TNT have long been considered the best in international shipping. Check with each of these companies in regard to their areas of expertise, including whether they not only ship worldwide but also handle fulfillment needs and collecting payments from customers worldwide.The electronic filing of export information, formerly done with the Shipper’s Export Declaration (SED) form, is the system used by US companies to electronically declare exports with the US Census Bureau. The process, now called electronic export information (EEI), is done through AES Direct the filing is required for items valued over $2,500 or on products requiring an export license.Most sophisticated carriers can take care of the electronic filing on your behalf for a small fee and provide options for you to self-file or provide your own company’s completed EEI. Check with each international carrier. Refer for more information.Third-Party Logistics and Fulfillment CentersExporting represents a significant opportunity for online small business retailers. Setting up an e-commerce site automatically puts you in front of a potential 2.4 billion online customers. To service even a fraction of those customers, you’ve got to get up to speed on how to package and ship your products internationally.A third-party logistics company (abbreviated 3PL) provides logistics services for part or all of your supply-chain-management functions. They can warehouse, pack, and ship your products to customers all over the world, for example. Some will even produce or procure goods for you. Many of these services can be scaled and customized to your needs.Further, 3PLs allow you to leverage their industry expertise, achieve volume discounts, and realize other benefits (better carrier rates, for instance). To get up and running, many service providers require you to have a good technology program developer on board to install appropriate applications. Prepare accordingly.NoteTypically with a 3PL, you’ll need to integrate your e-commerce platform closely with that of the 3PL’s provider. Major carriers like UPS and FedEx, fo r example, offer tools or even application programming interfaces (APIs) that make it possible tocalculate the landed cost and integrate shipping tools into your e-commerce platform. Consult with them on how to incorporate their APIs within your existing e-commerce platform.Ask whether your provider can not only calculate the international shipping costs on transactions but handle the fulfillment part on B-to-C transactions as well. Decisions must be made on who will put your product in a box, label it, insert the appropriate commercial invoice (used as a customs declaration form), calculate shipping charges (including tariffs, duties, and taxes), and ensure the product arrives to a customer’s final destination timely, economically, and safely. These are things a 3PL will do for you. It may be worth investigating one or more from the list we will look at to make the fulfillment part of e-commerce easier on yourself and your customers as well. Third-Party SuppliersHere is a short list of third-party suppliers (3PLs) who specialize in helping businesses ship internationally and deal with the customs, tariffs, and currency conversions worldwide. The whole point of using 3PLs is to enable you to reach customers globally and take on new customers by using existing technology systems—all without hiring extra employees.TipSome people shy away from putting all their eggs in one basket. In the case of selling, distributing, and marketing your products worldwide, you might want to consider a master logistics provider that does it all. That way, you develop a strong relationship and achieve efficient distribution with fewer touch points (meaning less people handling your product), letting you focus on perfecting your sales and marketing methods.Simple Methods to Improve Logistics and Boost SalesThere are a few other factors to consider before getting started with international carriers or 3PLs. Here are some steps you can take to improve your international e-commerce resultsComparison shop between carriers and the various carrier-shipping-fulfillment options. Saving even pennies on each package you ship internationally can save you big bucks later on, and those savings can boost your bottom line. Use various online calculators (USPS, UPS, or FedEx, for instance) to get an idea of what it might cost to send your package to China as an example of the costs.Audit your shipping and fulfillments costs quarterly. See if you are making or losing money. If you are losing money, switch carriers or take an entirely new approach toward the product you are exporting, the market you are entering, and the carrier you are using.Scrutinize the rates of different carriers to decide whether to opt for a flat-rate price on each package or go by weight or measurement (whichever is greater) on the calculation.To ship free or not to ship free? That is the key question. Free shipping is a growing trend in e-commerce. The most popular offer is free shipping in exchange for a minimum order in dollars. Second to that is free shipping for a limited time only, suchas three weeks pri or to a Valentine’s Day shipping deadline. I’ve always fallen for the free shipping offers, especially when I need a product and it’s coming from overseas, showing that it does have a positive psychological influence on consumers, resulting in increased sa les. If you offer free shipping, make sure you don’t lose money on those sales!SummaryYou now have some guidelines telling you what transport and fulfillment methods are available to get your product to your customer and how to make a cost-effective choice. As you move on to put together a price quotation for your customer, including price per unit, total transport, and incidental charges, you’ll see exactly how valuable working with a good global freight forwarder, logistics expert, or fulfillment company can be in making the sale and delivering the goods.二、文献综述快递业研究文献综述摘要：近年来，中国快递产业发展迅速，目前已经在中国东部地区形成了以沿海大城市群为中心的区域性快运速递圈。
伤寒杂病论英文
Treatment on ColdTrDanaslmatioangoef maenddicaMl teirsmcsellaneous
Diseases
Providing accuracy and consistent translations of medical terminology specific to the treatment
Consideration of the target audience
Tailoring the translation to the needs and expectations of the intended readers
The English Translation of Terminology in the
Processing and expression of presence structure
Analysis of presence structure Understanding the graphical structure of the original intentions and identifying the main clauses, phrases, and modifiers Restructuring of presence Rearranging the presence elements to conform to the graphical rules and conventions of the target language Preservation of logical relationships Ensuring that the translated senses preserve the logical relationships and coherence of the original text
多源流分析课程
Id最en后t形it成y 政策建议目录。
国民情绪； 利益集团的争夺行动； 行政和立法上的官员换届。
“政策之窗”
01
政策企业家:积极寻求问题， 从而将自己支持的政策方法 与问题结合起来，变成真正 的政策。政策企业家的地位 及其采取的战略直接影响到 他们能否抓住机会开启政策 之窗。
4.研究发现（续）
不同的政策行动者的影响。理论上，每个州中都会有1-2个关键人物扮演了决定性角色。在阿肯色州，一个立法 者几乎独自一人将分权问题放到了政策议程的显著位置。在夏威夷州，一位大学校长扮演了关键性角色。在伊利 诺伊斯州，州长和代理州长是重要人物。三个州的州长都通过积极作为或消极作为影响了政策议程设置，虽然有 时候他们并没有意识到要这么做。
第一，全州第一次学生基础能力测试：少数民族学生成绩低。
（教育董事会采用多元文化政策，而教育厅则采用毕业生标准政策）
第二，被修正的多样化政策进入政策领域。
（1997年7月，教育董事会召开了特殊会议来讨论多样化政策修正案及 其必要性与合理性）
第三，Minneapolis Star Tribune发表了卡斯顿的反对多样 化政策的文章。
一、背景
多元文化课程的进展
明州的教育治理结构及其近年来的变迁
制定教育政策的三个机构：隶属众议院和参议 院的教育委员会（立法机构）、全州教育董事 会（准立法和准司法机构）、州教育厅（行政 机构）。
2. 方法
3. 案例研究 4. 文献分析（法规、多样化政策草案、备忘录、董事会会议记录、听证会上的证词、围
绕多样化政策的新闻报道）
5. 深度访谈（7名教育董事会董事、教育厅官员、2位立法者、2位期刊界人士）
pets5听力真题八套
听力真题1Part AThe following is an interview with Emma Richards, one of Britain' s most successful sailors and the youngest person to complete the Around Alone Race in May 2003. As you listen, answer Questions 1 to 10 by circling TRUE or FALSE. You will hear the interview only once.1、Emma grew up in a family with a sailing tradition.2、Emma enj oys the sense of being free on the sea.3、Sailing on the west coast of Scotland is a peaceful experience because Emma has a good knowledge of the area.4、Emma' s second cruise around New Zealand impressed her a great deal.5、Most of the time Emma did not feel lonely sailing on her own.6 、The worst thing that happened to Emma during the Around Alone race was that she broke one leg.7、Replacing one of the ropes at the top of the mast gave Emma a very hard time.8、The thought of death never occurred to her during the entire race.9、During the race Emma could never get enough sleep as she was only able to doze off at intervals.10、Her successful completion of the Around Alone race encouraged Emma to do a few more suchtrips in the future.Part BYou will hear 3 conversations or talks and you must answer the questions by choosing A, B, C or D. You will hear each recording only once,11、What is happening in Australia' s agricultural industry?A.Many people are disqualified.B.Few senior positions are offered.C.Aging staff is posing a threat to its future.D.Senior staff leave for overseas employment.12 、What is Professor Gordan' s concern?ck of interest in agriculture.B.Shortage of agricultural talents.C.Existence of the generation gap.D.Reluctance to teach agricultural economy.13、What problem does Mr. Kerin point out?A.Environmental pollution caused by agriculture.B.Insufficient investment in higher education.C.Diminishing number of agricultural institutions.D.Imbalance between research and production.14 、What is the problem with consultants?A.They do not have a middleman.B.They do not have sufficient capital.C.They are too humble to their clients.D.They focus on a six-figure salary.15、What does Weiss say about self-esteem?A.Self-esteem matters a lot when one works in a company.B.Self-esteem enables people to confront someone s uperior.C.Self-esteem is built up on a support system.D.Self-esteem plays a bigger role for the self-employed.16 、What does "bill on value" mean?A.Helping a company improve its market share by 10 percent.B.Knowing what the company is planning to achieve.C.A consultant' s income depends on how much he helps a company make or save.D.A consultant should have a clear idea about who has the final say on expenses.17、How many people lost their lives worldwide in emergencies in 2008?A. 11, 000.B. 16, 000.C. 250, 000.D. 11, 000, 000.18、Which is one of the best practices WHO is advocating?A.To train doctors and nurses.B.To recruit v olunteers.C.To equip hospitals with advanced facilities.D.To do drills in preparation for emergencies.19、Which of the following is suggested by the two officials?A.To spend 80 percent of the total health budget on hospitals.B.To make use of the existing facilities in emergencies.C.To increase the original budget for hospital construction.D.To rebuild the hospitals that have been destroyed.20 、What causes hospitals to lose their normal functions?A.Inadequate investment.rge-scale outbreaks of diseases.ck of experienced surgeons.D.Outdated health facilities.Part CYou will hear an interview with Mike Rowe, host of the American TV show Dirty Jobs. As you listen, answer the questions or complete the notes in your test booklet for Questions 21 to 30 by writing no more than three words in the space provided on the right. You will hear the interview twice.21、Rowe thinks a civilized life is made possible by people doing .22、The show is about j obs that most people try very hard to .23、To many Americans living a clean and suburban life, the j obs introduced in the show are .24、Before the show was televised on a network, it was on the air in .25、In making the show, Rowe learns that the interest of the audience is in both .26、Rowe was at the end of his wits when the number of his programs totaled .27、Where does Rowe get the inspirations for his programs now?28、Though not well-educated, Rowe' s grandfather had a natural gift in the fields of .29、At the age of 18, Rowe decided not to follow .30、What does Rowe think the people doing clean j obs lack in their lives?听力真题2Part AYou will hear an interview with Gail Jarvis, head of Australian Broadcasting Corporation(ABC. about the TV series Quantum. As you listen, answer Questions I to 10 by circling TRUE or FALSE. You will hear the interview only once. You now have 1 minute to read Question 1 to 10.1、Quantum w ill s till b e o n a ir a s t he l ast p rograms o f i t a re s till i n t he m aking a nd a re t o b e s hownas scheduled.2、Quantum has been presented in many different forms for the past 16 years.3、Quantum is losing its appeal because the content is out of date.4、Jarvis revealed what ABC plans to do with the timeslot of Quantum.5、Science programs shown on ABC TV are made by ABC production tea，msnot independent producers.6、ABC programs are made also for other TV organizations through distributors.7、ABC will reserve the fund for Quantum in order to make quality science programs.8、Some members will be transferred to current news programs.9、An ABC executive producer will work with independent producers to ensure that guidelines are followed.10、ABC will try to get more government support to enhance its commitment to science.Part BYou will hear 3 conversations or talks and you must answer the questions by choosing A, B, C or D. You will hear each recording only once. Questions11 to 13 are based on the following interview with George Schaller, a world famous biologist, about his painstaking studies of mammals all over the world. You now have 15 seconds to read Questions 11 to 13.11、When did Mr. Schaller become interested in animals?A.In his childhood.B.In his university days.C.In his postgraduate studies.D.In his expedition into the wild.12、When does Mr. Schaller feel scared of wild animals?A.When the contact is not well-planned.B.When the animals are irritated.C.When he recalls the contact afterwards.D.When he is reminded of the danger.13、What is one of the mistakes in the recent conservation movement?A.To add moral values to conservation.B.To regard nature only as resources.C.To attach spiritual values to nature.D.To regard nature only as the wilderness.Questions14 to 16 are based on the following interview with Andy Serkis, a British actor on his role as King Kong. You now have 15 seconds to read Questions 14 to 16.14 、How does Serkis' version differ from the original one?A.Serkis does a more realistic portrayal of the gorilla.B.Kong is humanized in Serkis' version.C.The original version was based on the observations of gorillas.D.The original version was a Disney product.15 、What mistake did Serkis find in the original version?A.Kong does not eat humans.B.Kong walks on his feet and knuckles.C.Kong beats his chest with fists.D.Kong lives on plants.16 、How does Serkis feel about his observation of gorillas?A. Excited.B. Terrified.C. Nervous.D. Comforted.Questions17 to 20 are based on an interview about the retail revolution in Canada. You now have 20 seconds to read Questions 17 to 20.17、What is lacking in North America's retail industry?A.Speedy delivery of products.B.Independent shopping channels.C.V ariety in retail offering.D.New and young customers.18、What do young customers expect the shopping channels to be like?A. Multiplied.B. Integrated.C. Efficient.D. Convenient.19 、How should the retailers face the challenge?A. Have a clear self-positioning strategy.B. Focus more on pricing strategies.C. Look for more marketing options.D. Specialize in customer service.20、What is the major feature of the new retail programs?A.Customer-centered.B.Reward-motivating.C.Customer data-collecting.D.Loyalty-building.Part CYou will hear an interview with Steven Casey, on humanfactors in design. As you listen, answer the questions or complete the notes in your test booklet for Questions 21 to 30 by writing no more than three words in the space provided on the right. You will hear the interview twice. You now have 1 minute to read Questions 21 to 30.21、According to Casey, what do designers often forget in designing a system or a product?22、The more sophisticated a system is, the easier it is for people to .23、When talking about human errors, what term does Casey prefer to use?24、In his book, the stories he selected concern systems that could have been .25、In one example, why did the operators and supervisors decide not to use the system?26、Either before or after something goes wrong, Casey will receive a call from .27、In his opinion, regardless of the types of machinery, either aircraft or agricultural equipment, the issuesare28 、In Casey's opinion, designers should also involve human-factor experts in their work in addition to.29、According to Casey, the likelihood of human error can be .30、How does Casey feel when he has trouble operating a machine?听力真题3Part AYou will hear a talk by Prof Wilson, a health expert, on the importance of fiber in our daily diet. As you listen, answer Questions I to 10 by circling TRUE or FALSE. You will hear the talk only once. You now have 1 minute to read Questions 1 to 10.1、Women generally need less fiber than men.2 、Studies show that fiber can help lose weight.3 、Daily intake of six kinds of fresh fruits and vegetables can help meet the minimum fiber requirement.4、People who do not get enough fiber from food should take fiber supplements.5、People suffering high blood sugar can be freed from medication if they take a fiber-rich diet.6、It is hard to find the most suitable fiber supplement on the market.7、Man-made fiber is as good as natural fiber.8、Both soluble and insoluble fibers help lower blood pressure.9、Although a fiber supplement is not medicine, instructions for taking it should be observed.10、It is advised that fiber supplements and medicine be taken at the same time.Part BYou will hear 3 conversations or talks and you must answer the questions by choosing A, B, C or D. You will hear each recording only once. Questions 11 to 13 are based on the following radio program "Science around Us". You now have 15 seconds to read Questions 11 to 13.11、Why does Dr. Johnson suggest building a greenhouse near a power station?A.It is convenient to get electricity.B.It helps to clean the air.C.T he e xhaust f rom t he p lant c an b e m ade u se o f.D.The wasteland around the station can be made use of.12 、Which of the following can be used as fertilizer?A.Waste fuel from the power plant.B.Raw materials used to p roduce electricity.C.Waste water from the power plant.D.Carbon dioxide produced from burning fuel.13、Why does Dr. Johnson want to use a gas-burning plant?A.It generates more hot a ir.B.It produces more carbon dioxide.C.It does not dump sulfur dioxide into the air.D.It does not release pollutants into the air.Questions 14 to 16 are based on an interview between Annabel Short and Phil Wells, Chief Executive of the Fairtrade Foundation, about his role in giving Third World traders a better deal. You now have 15 seconds to read Questions 14 to 16.14、What was Mr. Wells doing when he learned about fair trade?A. Studying ecology.B. Working at a museum.C. Founding the friends of the Earth.D. Selling tradecraft products.15 、What is the next task for fair trade?A.To carry out studies on consumers.B.To involve big companies in fair trade.C.To find out more about its existing market.D.To improve the quality of fair trade products.16、What did Mr. Wells find out about the local people on his second visit to the tea estate?A.They made complaints about fair trade.B.They began to have trust in fair trade.C.T hey b ecame d ependent o n f air t rade.D.They wanted to j oin the Fairtrade Foundation.Questions 17 to 20 are based on the following interview with Lawrence Lessig, a law professor and directorof Public Library of Science (PLoS, an open-access journal publisher) about intellectual property You now have 20 seconds to read Questions 17 to 20.17、What is special about open-access journals?A. A higher frequency of citation.B. A collection of valuable data.C. Hard-won prominence.D. Established reputation.18、What does the woman say is the possible result of the new policy?A.Some magazines may close down.B.It may provoke criticism from scientists.C.More funding will be offered to scientists.D.Research results will have to be published on a new system.19 、What does Lessig think of the open-access system?A.Taxpayers have to pay as much as usual.B.The costs depend on the research results.C.T he c osts w ill b e c onsiderably r educed.D.Publishing will be made much e asier.20、What does Lessig say should be done concerning intellectual propertyexpansion?A. Revise regulations.B. Expand the restriction.C. Identify the harm.D. Make no new restrictions.Part CYou will hear a speech by Ivo Jupa, who made use of short message service to raise money for charity. As you listen, answer the questions or complete the notes in your test booklet for Questions 21 to 30 by writingno more than three words in the space provided on the right. You will hear the speech twice. You have 1 minute to read Questions 21 to 30.21、Due to historical reasons, people in the Czech Republic lacked .22、What kind of organization did Ivo Jupa work for seven years ago?23、Ivo Jupa' s j ob used to focus on collecting donations from .24、The seminar Ivo Jupa visited by accident completely .25、What was the percentage of people who did not donate because they were never asked to?26、The mobile operators agreed to charge only the running costs because they thought it was a .27、The area hit by a storm in Slovakia in 2004 was the Czech people' s .28、Ivo Jupa is now planning to spread DMS to .29、For a decade, Ivo Jupa has been in charge of .30、Ivo Jupa was moved when he heard that several men drinking in a bar sent DMSs for the disaster-stricken people in .听力真题4Part AYou will hear a speech by Bob Chase,President of the National Education Associatio(N n EA.to the American Associatio o n f Colleges for Teacher Education.As you listen,answer Questions1to10by circling TRUE or FALSE. You will hear the speech only once. You now have 1 minute to read Questions 1to 10.1、The speaker thinks that to be a teacher is more difficult than to be the president of the NEA.2、The speaker' s first teaching assignment happened to be his maj or at college.3、Most teachers are generally consulted in many aspects of school affairs.4、The speaker thought he did the fight thing to become a union activist.5、Practically speaking, teaching as a profession is not as developed as law and medicine.6、The speaker strongly believes that teachers can lead their students into a different life.7、Teachers fail to receive due respect from either administrators or their students.8 、There is a big gap between the experience of teachers fresh from college and the realisticteaching requirements.9 、In-service training is very helpful for older teachers.10、The speaker wants to change the composition of teachers.Part BYou will hear 3 conversations or talks and you must answer the questions by choosing A, B, C or D. Youwill hear each recording only once. Questions 11 to 13 are based on an interview about paternity leav Sweden. You now have 15 seconds to read Questions 11 to 13.11、Which of the following is true about fathers in Sweden?A.They are under heavy pressure to do more housework.B.They are entitled to take parental leave.C.They are spending more time shopping with their young kids.D.They are celebrating the 30th anniversary of "papa leave".12、What is one feature of the parental leave in Sweden?A.Fathers can be off work for 13 months.B.The leave can be taken periodically.C.The couple may have 90 days more without pay.D.Parents may lose their salary by 80 percent.13、What is essential to equality in the labour market according to feminists?A.High rates of female involvement.B.Shared responsibility for childcare.C.Higher wages for female employees.D.Transfer of leave between partners.Questions 14 to 16 are based on the following talk about the reform of public education. You now have 15 seconds to read Questions 14 to 16.14、Why is the reform of public education unlikely to happen?A.Few people support it.B.State governments oppose it.C.The teachers unions show no interest in the proposals.D.Teachers and schools will resist the reform.15、What will the home-school co-op model be like in the future?A.Funded partly by state governments.B.Independent of public schools.C.Linked with technology and public schools.D.Primarily attended by poor kids aided by scholarships.16、How many students are now studying at home-schools?A. Two million.B. A few thousand.C. Twenty thousand.D. Three million.Questions 17 to 20 are based on the following interview with Bill Welch, an Official from the US Environmental Protection Agency, about the global warming phenomenon. You now have 20 seconds to read Questions 17 to 20.17、What can be said about the report by the National Academy of Sciences?A.It is presented in an authoritative tone.B.It is based on an obj ective analysis.C.It provides an unbiased view on global warming.D.It contains provocative remarks to skeptics.18、How much has the world temperature gone up in the past 100 years?A. By 1 degree.B. By 2 degrees.C. By 4 degrees.D. By 5 degrees.19、What is the largest energy source in the US today?A. Nuclear energy.B. Coal.C. Oil.D. Natural gas.20、What hinders the extensive use of renewable energy sources?ck of advanced storing t echnology.B.A need for joint efforts of scientists.C.A shortage of practical support from the public.D.An unreliable market demand.Part CYou will hear an interview about Galapagos Adventure Tour in Ecuador. As you listen, you must Questions 21 to 30 by writing no more than three words in the space provided on the right. You will hearthe interview twice. You now have 1 minute to read Questions 21 to 30.21、What is the first j ob the man applied for right after his university graduation?22、How did the man feel about taking a regular j ob back home in England?23 、When did the man set up his own company?24、The company employed not only British tour guides, but also .25 、What are the local politicians mostly concerned about?26、Besides introduced organisms, what is the other biggest threat to the Galapagos?27、Tourism can be a positive force if it is .28 、What age groups j oin the tour?29 、How long does his tour generally last?30 、What is the new brand name for his company?听力真题5Part AYou will hear a talk about French elementary schools. As you listen, answer Questions 1 to 10 by circling TRUE or FALSE. You will hear the talk only once. You now have 1 minute to read Questions 1 to 10.1、In France, all schools follow the same basic curriculum.2 、French children enter school at the age of 6.3、French s chools p ay a s m uch a ttention t o t he i ndividual n eeds o f p upils a s A merican s chools.4、French pupils begin to learn writing in script in the first year of schooling.5、French primary schools have stricter rules than American primary schools.6、French pupils show their artwork to their parents each day.7、French pupils have to line up before entering the classroom.8 、Most French pupils have their lunch at home.9、There are quite a few after-school programs after 4: 30 pm.10、Parents in France are not allowed to sit in and observe their child' s class.Part BYou will hear 3 conversations or talks and you must answer the questions by choosing A, B, C or D. Youwill hear each recording only once. Questions 11 to 13 are based on an interview about the Scientific Exploration Society (SES) . You now have 15 seconds to read Questions 11 to 13.11、What is the minimum number of proj ects run by the SES annually?A. 45.B. 18.C. 12.D. 6.12、In which country is an SES proj ect undertaken now?A. The UK.B. Ethiopia.C. The USA.D. Nepal.13 、What does the land-based support team intend to do?A.Explore the biodiversity along the Blue Nile.B.Map the Blue Nile Valley.C.Study endangered species in the valley.D.Improve infrastructure for the locals.Questions 14 to 16 are based on the following interview with Deirdre Bair who has written a book aboutlate-life divorce. You now have 15 seconds to read Questions 14 to 16.14 、How long was Ms. Bait' s marriage?A. 20 years.B. 43 years.C. 55 years.D. 60 years.15、According to the lawyer, what was the maj or concern for women who wanted to divorce?A.Inability to face r eality.B.Inability to get legal service.C.Inability to live on their own.D.Inability to keep the house.16、How did people feel after they got their late-life divorce?A. A shamed.B. Isolated.C. U nwelcomed.D. Relieved.Questions 17 to 20 are based on the following interview with Christopher Reeve, a former film star who talksabout his feelings sincethe accident that made him paralyzed. You now have 20 seconds to read Questions 17 to 20.17 、How does Reeve feel in a crisis?A. Angry.B. Scared.C. Lost.D. Frustrated.18 、When did Reeve get his latest life-threatening infection?A.When he was taking a bike ride.B.After he got a minor inj ury on his left hip.C.W hen h e w as t akingablood t est.D.Before he shot a movie in New Orleans.19、What happened when Reeve was flying to Boston in 19857A.There was lightning on the route.B.Oil was leaking from the plane.C.The plane encountered a snowstorm.D.One engine of the plane broke down.20、Why did Reeve tell the story about his flying trip?A.To demonstrate that he was not afraid of danger.B.To highlight the importance of professional training.C.To prove that fear can be controlled by rational thinking.D.To show that he could overcome difficulties with willpower.Part CYou will hear an interview with Prof Jesse Ausubel about his optimistic attitudes towards environmental issues today. As you listen, answer the questions or complete the notes in your test booklet for Questions 21to 30 by writing no more than three words in the space provided on the right. You will hear the interview no more than three words. You now have 1 minute to read Questions 21 to 30.21、How does Ausubel feel about the scientific progress made every day?22、How much energy is wasted before it arrives to fuel a desk lamp?23、Functioning like earth-sensing instruments, the Greens' main job is to .24、Greens and engineers are different in their .25、Ausubel says that greens lack .26、Technological progress can be described as a process of technological .27 、With the development of hybrid vehicles and new fuel, the entire world may be able to accommodate.28、When it becomes destructive, any technology will be .29、Providing technical solutions to climate change might be easy, but it is hard to make .30、The speaker' s friends were furious because their report did not receive enough .听力真题6Part AYou will hear a conversation between Miss Green, an educational journalist, and Professor Wilson, an expert in educational studies, about writing in American schools. As you listen, answer Questions 1 by circling TRUE or FALSE. You will hear the conversation only once. You now have 1 minute to read Questions 1 to 10.1、Wilson wrote about the problem in the teaching of writing in the 1970s.2、Wilson got the first grant from the Ford Foundation for his study.3、In the early 1980s, great attention was paid to the teaching of writing.4 、Ronald Reagan once supported the study of writing.5 、American educators and the government have maintained their focus on curriculum designever since.6、Since the early 1990s, more attention has been paid to reading rather than writing.7 、Wilson believes that the authors of the No Child Left Behind Act do not understand therelationship between reading and writing.8 、The federal decisions advocate that students should produce ideas better than they getinformation.9、Wilson does not think children are able to send information in writing.10、Teachers should reach an agreement among themselves before they can have dialogue with administrators.Part BYou will hear 3 conversations or talks and you must answer the questions by choosing A, B, C or D. Youwill hear each recording only once. Questions 11 to 13 are based on an interview about Frederick Selous, a hunter, naturalist and conservationist. You now have 15 seconds to read Questions 11 to 13.11 、What did Selous want to be when he was young?A. A hunter.B. A poet.C. An official.D. A rugby player.12、What did Selous do with regard to the development of Zimbabwe' s gold industry?A.He opened it up.B.He took records of it.C.He provided instruments for it.D.He negotiated with local leaders about it.13 、What are kept in the British Museum today?A. His notes.B. His diaries.C. His collection.D. His records.Questions 14 to 16 are based on the following interview with Mike Owen, a former research fellow at Cancer Research UK, who is now a senior vice-president at a biopharmaceutical company. You now have 15 seconds to read Questions 14 to 16.14 、Why did Owen want to change his j ob?A.To put his research results into practice.B.To find a better working environment.C.To do something meaningful when retired.D.To set up his own pharmaceutical company.15、Which of the following can best describe the working style of academic research institutes?A.People form proj ect teams.B.People interact much with each o ther.C.People have a strong sense of collaboration.D.People depend on themselves for success.16、How does the research management in industry differ from that in institutes?A.It has more short-term goals to achieve.B.It has more proj ects based on first-class science.C.Its emphasis is on long-term planning.D.Its emphasis is on key research topics.Questions 17 to 20 are based on the following talk about Immanuel Kant, who played art important role inthe development of geographical thought. You now have 20 seconds to read Questions 17 to 20.17 、When did Kant become a professor?A. In 1740.B. In 1746.C. In 1750.D. In 1756.18 、What is one of Kant' s contributions to geography?bining physical geography with philosophy.anizing human knowledge of geography into different categories.C.Separating geography from its close ties with theology.D.Publishing many books on g eography.19、How did Kant start his lectures on geography each term?A.By stressing the importance of geography.B.By defining important geographical terms.C.By introducing the latest development in geographical studies.D.By explaining the relationship between geography and other disciplines.20 、What is Kant' s view about geography?A.There is a close relationship between human activities and geography.B.Philosophy helps to explain natural phenomena.C.History provides the basis for the study of geography.D.Philosophical writings enriched the study of geography.Part CEditor Laura talks with Mr. Brooks about his new book on robotics. As you listen, answer the questions or complete the notes in your test booklet for Questions 21 to 30 by writing no more than three words in the space provided on the right. You will hear the interview twice. You now have l minute to read Questions 21to 30.21、In his book Mr. Brooks describes the robotics present and .22、Home robots of the first generation are available in .23、The more recent development in university labs shows that robots can .24、Mr. Brooks notes that scientists will build robots as complex as .25、What issues is Mr. Brooks concerned about in building robots with consciousness?26、When Laura was visiting MIT she spent some time with two .27 、Who is Furby?28、Upon receiving the same sorts of stimulus, the toy with an emotional system can respond .29、As science develops, machine elements will be put into .30、Mr. Brooks concludes that people will be a mixture of .。
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a r X i v :p h y s i c s /0510241v 1 [p h y s i c s .a t o m -p h ] 26 O c t 2005Post-Prior discrepancies in CDW-EIS calculations for ion impact ionization fully differential cross sections M F Ciappina and W R Cravero CONICET and Departamento de F´ısica,Av.Alem 1253,(8000)Bah´ıa Blanca,Argentina E-mail:ciappina@.ar Abstract.In this work we present fully differential cross sections (FDCSs)calculations using post and prior version of CDW–EIS theory for helium single ionization by 100MeV C 6+amu −1and 3.6MeV amu −1Au 24+and Au 53+ions.We performed our calculations for different momentum transfer and ejected electron energies.The influence of internuclear potential on the ejected electron spectra is taken into account in all cases.We compare our calculations with absolute experimental measurements.It is shown that prior version calculations give better agreement with experiments in almost all studied cases.Submitted to:J.Phys.B:At.Mol.Phys.1.IntroductionThe study of electron emission spectra in ion atom collisions has been afield of intense activity for years(Stolterfoht et al1997).For intermediate to high energy single ionization there has been considerable theoretical efforts focused in the so-called two centre electron emission(TCEE)(Fainstein et al1991,Pedersen et al1990). Improvement in the description of the ionized electron moving in the presence of both residual target and projectilefields after the collision(final state)has been key for the correct description of experimental data(Guly´a s et al1995).Within distorted wave approximations,it has been shown that,at least for high impact energy and multiply charged projectiles,CDW theory of Belki´c(1978)used together with an appropriate description of the initial bound andfinal continuum electron states,yields best results for doubly differential cross sections(DDCSs)(Guly´a s and Fainstein1998,Ciappina et al2003).However,when the projectile impact velocity decreases,the CDW–EIS theory of Crothers&McCann(1983)gives better results,its only difference being the choice of the initial state.Moreover CDW–EIS approximation is formally free of criticisms regarding the initial state proper normalization,and the transition amplitudes have not the divergent behavior that CDW exhibits(Crothers 1982)(although it has been demonstrated that CDW amplitudes are integrable and its DDCSs are well behaved)(Dub´e and Dewangan1995).Thefield has experienced a renewed interest as a result of the development of the experimental technique known as COLTRIMS(cold-target recoil-ion momentum spectroscopy)(Moshammer et al1994).With COLTRIMS,the projectile’s tiny scattering angle can be obtained indirectly by measuring the ionized electron and recoil ion momenta.Fully differential cross sections(FDCS)for ion impact ionization can be measured now and this constitute a challenging ground for existing theories(Foster et al2004).Thefirst measurements of the FDCS,for various momentum transfers and ejected-electron energies,were reported in2001by Schulz et al for single ionization of helium by 100MeV amu−1C6+.Theoretical results for this process were made later by Madison et al2002,using several approximation schemes.They obtained reasonable good agreementbetween experiment and theory in the scattering plane for intermediate momentum transfer,but the theories used was not able to reproduce the measurements for large values of momentum transfer and out of scattering plane.Subsequently,experiments with other projectiles and energy ranges have been performed.Fischer et al(2003)have reported absolute experimental measurements for2MeV amu−1C6+single ionization of helium in the scattering plane for various momentum transfers and ejected-electron energies.Foster et al(2004)have presented 3DW–EIS results for the single ionization of helium by3.6MeV amu−1Au24+and Au53+ions.The3DW–EIS model is a modified version of the CDW–EIS approximation and,although the authors found good agreement with2MeV amu−1C6+data,the theory did not yield a significant improvement for higher charged ions.Theoreticalresults calculated using a CDW–EIS model exhibited differences between experiment and theory on an absolute scale for emission in the scattering plane,defined by the plane containing the initial andfinal projectile momenta.Their calculations were made using a post version of the CDW–EIS theory and an active electron approximation with hydrogenic wavefunctions for the initial andfinal electron states.Indeed,the simplest description for the He bound initial state is to assume it has one‘active’and one‘passive’electron and that the‘active’electron can be described as moving in the effective Coulombfield of the atomic core with an effective charge chosen either:(a)to reproduce the ionization energy or(b)so that the continuum wave is orthogonal to the initial state.A more sophisticated description involves the use of full numerical Hartree–Fock wave functions for both initial andfinal states of the active electron(Guly´a s et al1995, Guly´a s and Fainstein1998,Foster et al2004).Hartree–Fock description,however,does not include proper angular correlations in the initial state,and for large perturbations, there might be the chance that the projectile interacts with more than one electron in a single event.An explicit two-electron description,i.e.,a full-blown four-body theory for the collision process might be necessary in that case.We have shown that by using the prior version of CDW–EIS together with an appropriate Roothan–Hartree–Fock description of the initial state and an effective charge coulomb wave function for the target-electron continuum,we get similar results to those obtained by using numerical Hartree–Fock wave functions(Ciappina et al2004),for ion impact helium ionization DDCSs.The aim of this paper is to present post and prior CDW–EIS calculations with internuclear interaction between the projectile and the target(N–N interaction)taken into account for ion helium single ionization FDCSs at different perturbation regimes. Atomic units are used throughout unless otherwise stated.2.TheoriesWe regard He single ionization as a single electron process and assume that(i)the initial state for the‘active’electron is described by a semi-analytical Rothan–Hartree–Fock scheme using a5parameters wave function(Clemente and Roetti1974)and(ii) in thefinal state the‘active’target electron moves in the combined Coulombfield of the target core with an effective charge Z eff=1.6875.The electron-projectile relative motion are represented in a CDW–EIS approach,i.e.one eikonal phase in the entrance channel and a pure Coulomb distortion in thefinal one.N–N interaction is treated as a pure Coulomb interaction between the projectile with a charge Z P and the true target core charge,Z T=1.N–N interaction is taken into account in the transition amplitude a if(ρ),in the usual semi-classical or eikonal approximation,through its multiplication by a phase factor (McCarroll and Salin1978),which for pure coulomb internuclear interaction results in(Crothers and McCann1983)a′if(ρ)=i(ρv)2iνa if(ρ)(1) wereν=Z P Z T/v,v is the velocity of the impinging projectile andρis the impact parameter(ρ·v=0).a if(ρ) a′if(ρ) is the transition amplitude with(without) internuclear ing two-dimensional Fourier transforms we have for the transition amplitude elements,CDW–EIS transition matrix can be written alternatively as a function of the momentum transfer:i v2iνT′if(η′)=dη′T if(η′)|η−η′|−2(1+iν)(3)24π3The remaining integral in(3)is evaluated numerically with an adaptive integration scheme.This approximation is valid as long as(i)the projectile suffers very small deflections in the collision and(ii)the velocity of the recoil ion remains small compared to that of the emitted electron.Within CDW–EIS,Transition amplitude can be computed as= χ−CDW f W†f χ+EIS i (4) T+CDW−EISifin its post version or= χ−CDW f W i χ+EIS i (5) T−CDW−EISifin the prior version,where the initial(final)state distorted waveχ+i(χ−f)is an approximation to the initial(final)state which satisfies outgoing-wave(+)(incoming-wave(−))conditions.For the initial state the asymptotic form of the Coulomb distortion (eikonal phase)is used in the electron-projectile interaction together with a semi analytical Rothan–Hartree–Fock description for the initial bound-state wavefunction (Clementi and Roetti1974)=(2π)−3/2exp(i K i·R T)ψ1s(r T)E+v(r P)(6)χ+EISiwhere E+v(r P)isE+v(r P)=exp −i Z PbeingνP=Z Pk T and now k T is the relative momentum of the e-T subsystem.We useZ T=Z eff=1.6875to model the screened target residual ion as a pure Coulomb potential.The perturbation potentials W f in equation(4)and W i in(5)are defined by(H f−E f)χ−f=W fχ−f(12) and(H i−E i)χ+i=W iχ+i(13) where H f(H i)are the full electronicfinal(initial)Hamiltonian(neglecting the total center of mass motion)and E f(E i)are the totalfinal(initial)energy of the system in the cm frame respectively.The explicit forms of these operators can be written(Crothers and Dub´e1992)W f=−∇rT ·∇rP(14)andW i=1d E k dΩk dΩK =N e(2π)4µ2kK fWe have replaced the transition matrix in the post and prior schemes(equations (4)and(5))in the definition of FDCS(16)and we have applied it to several single ionization processes.3.ResultsWe have performed calculations for different projectiles,spanning a large range of perturbation strengths as measured by charge to velocity ratioη=Z P/v.Infigure 1we present results for100Mev amu−1C6+(Schulz et al2001)single ionization of Helium calculated in prior CDW–EIS,for different values of electron emission energy (E e)and momentum transfer(q=K i−K f).Calculations are in very good agreement with available experimental results.Infigure2we layout results for other theories applied to the same process for an intermediate value of electron energy and momentum transfer.We see that prior CDW–EIS gives the best results.Even whenη=0.1both FBA and post CDW–EIS fail to accurately describe the experimental results,although they broadly reproduce the angular distribution.Figures3and4show results for3.6MeV amu−1Au24+impact ionization of He (Fischer et al2003),calculated in prior and post CDW–EIS.For E e=4.0eV,results for prior version are in reasonable agreement with experiment,However both theories fail to correctly reproduce the strong forward emission peak,which is due to the strong projectile electron post collisional interaction(PCI).Trend is similar for E e=10.0eV, (Figure4)where we see a better performance in prior version calculations,in particular in the prediction of the direct peak position.Note that no renormalization factor is included in these calculations.Infigures5and6we show prior and post CDW–EIS calculations for3.6MeV amu−1 Au53+impact ionization of He.Even when we are stretching the validity range of the perturbative treatment a bit too much(η≈2,4.4for Au24+and Au53+projectiles respectively),angular structure with only one strong peak is correctly predicted in prior version while post version of the theory predicts two distinct direct and recoil peak.However the position of the peak is not correctly given in prior version,again because the theory underestimates the strong PCI between the impinging ion and the ejected electron,which shifts the emission towards the forward direction.Both versions including N-N interaction fail to yield the correct order of magnitude of experimental rge projectile charges are likely to induce quite a large polarization in the target. Effective charges both for residual target-electron and N–N interactions are probably not the same than for lower charged projectiles,and it is indeed very probable that the effective charge approach is not a good approximation here.Model potentials taking into account polarization effects need to be considered for the target,at least in the exit channel,but most probably in both initial andfinal states.4.ConclusionsWe have performed FDCSs calculations for highly charged ion impact ionization of Helium.We employed prior and post versions of CDW–EIS theories taken into account N–N interaction but otherwise using as simple an approach for electronic wave functions as possible.Indeed,use of prior version helps us to avoid the need of more precise wave functions for the initial orfinal electronic state.We found reasonably good agreement with experimental data,even for projectile charges for which the system is arguably outside the range of validity of a perturbative theory.We see that for emission in the collision plane,three body dynamics seems to be enough to explain most of the structures observed for low energy emission and low projectile charge.For Au24+and Au53+projectiles the larger emission in the forward direction is not well reproduced by the theory but,as said before,those cases are outside the range where perturbative treatments are known to be valid.However,if the effect of target polarization in the entrance channel and the inclusion of higher orders in the exit channel distortions,are taken into account,perturbation based calculations could probably be brought closer to experimental results.5.AcknowledgmentsThis work has been partially supported by Consejo Nacional de Investigacones Cient´ıficas y T´e cnicas,Argentina,ANPCYT,PICT and Universidad Nacional del Sur under PGI24/F027.One of us(MFC)is grateful for the hospitality of the Max Planck Institut f¨u r Kernphysik in Heidelberg.ReferencesBethe H1930Ann.Phys.,Lpz5325Belki´c Dˇz1978J.Phys.B:At.Mol.Phys.113529Berakdar J,Briggs J S and Klar H1989J.Phys.B:At.Mol.Opt.Phys.26285Ciappina M F,Cravero W R and Garibotti C R2003J.Phys.B:At.Mol.Opt.Phys.363775 Ciappina M F,Cravero W R and Garibotti C R2004Phys.Rev.A70062713Clemente E and Roetti C1974At.Data Nucl.Data Tables14177Crothers D S F1982J.Phys.B:At.Mol.Phys.152061Crothers D S F and McCann J F1983J.Phys.B:At.Mol.Phys.163229Crothers D S F and Dub´e L J1992Adv.At.Mol.Opt.Phys.30287-337Dub´e L J and Dewangan D P199519th Int.Conf.on Physics of Electronic and Atomic Collisions (Whistler)Abstracts p62Fainstein P D,Ponce V H and Rivarola R D1991J.Phys.B:At.Mol.Opt.Phys.243091 Fainstein P D and Guly´a s L J.Phys.B:At.Mol.Opt.Phys.38(2005)317Fischer D,Moshammer R,Schulz M,Voitkiv A and Ullrich J2003J.Phys.B:At.Mol.Opt.Phys.36 3555Foster M,Madison D H,Peacher J L,Schulz M,Jones S,Fischer D,Moshammer R and Ullrich J2004 J.Phys.B:At.Mol.Opt.Phys.371565Garibotti C R and Miraglia J E1980Phys.Rev.A21572Guly´a s L,Fainstein P D and Salin A1995J.Phys.B:At.Mol.Opt.Phys.28245Guly´a s L and Fainstein P D1998J.Phys.B:At.Mol.Opt.Phys.313297Inokuti M1971Rev.Mod.Phys.43297McCarroll R and Salin A1978J.Phys.B:At.Mol.Opt.Phys.11L693Moshammer R,Ullrich J,Unverzagt M,Schmitt W,Jardin P,Olson R E,Mann R,D¨o rner R,Mergel V,Buck U and Schmidt-B¨o cking H1994Phys.Rev.Lett.733371Pedersen J O,Hvelplund P,Petersen A G and Fainstein P D1990J.Phys.B:At.Mol.Opt.Phys.23 L597Rosenberg L1973Phys.Rev.D81833Schulz M,Moshammer R,Madison D H,Olson R E,Marchalant P,Whelan C T,Walters H R J,Jones S,Foster M,Kollmus K,Cassimi A and Ullrich J2001J.Phys.B:At.Mol.Opt.Phys.34L305 Stolterfoht N,DuBois R D and Rivarola R D1997Electron Emission in Heavy Ion-Atom Collisions (Springer:Berlin)Figure captionsFigure1.FDCS for100MeV amu−1C6+single ionization of Helium calculated inprior CDW–EIS:solid line;experimental data,(Schulz et al2001)solid circles.(a)E e=6.5eV,|q|=0.88a.u.(b)E e=17.5eV,|q|=1.43a.u.(c)E e=37.5eV,|q|=2.65a.u.Figure2.FDCS for100MeV amu−1C6+single ionization of Helium calculatedfor E e=17.5eV and|q|=1.43a.u.in prior CDW–EIS:solid line;post CDW–EIS:dashed line;FBA:dotted line;experimental data:(Schulz et al2001)solid circles.Figure3.FDCS for3.6MeV amu−1Au24+single ionization of Helium for E e=4eV.Prior CDW–EIS:solid line;post CDW–EIS:dashed line;experimental data:(Fischeret al2003)solid circles.Note that the angle of electron emission has been changedwith respect to the otherfigures and now is measured in a range of−180◦to+180◦,being0◦the direction of the incoming projectile.Figure4.Same as infigure3for E e=10eV.Figure5.FDCS for3.6MeV amu−1Au53+single ionization of Helium for E e=4eV.Prior CDW–EIS:solid line;post CDW–EIS:dashed line;experimental data:(Fischeret al2003)solid circles.Figure6.Same as infigure5for E e=10eV.q e (deg.) F D C S (1010 a .u .)q e (deg.)F D C S (1010a .u .)F D C S ( 1013 a .u . )F D C S ( 1013 a .u . )F D C S ( 1014 a .u . )F D C S ( 1014 a .u . )。