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Interdependencies
Selected AbstractsHealth Care Supply Chain Design: Toward Linking the Development and Delivery of Care Globally,DECISION SCIENCES, Issue 2 2009Kingshuk K. Sinha ABSTRACT This article is motivated by the gap between the growing demand and available supply of high-quality, cost-effective, and timely health care, a problem faced not only by developing and underdeveloped countries but also by developed countries. The significance of this problem is heightened when the economy is in recession. In an attempt to address the problem, in this article, first, we conceptualize care as a bundle of goods, services, and experiences,including diet and exercise, drugs, devices, invasive procedures, new biologics, travel and lodging, and payment and reimbursement. We then adopt a macro, end-to-end, supply chain,centric view of the health care sector to link the development of care with the delivery of care. This macro, supply chain,centric view sheds light on the interdependencies between key industries from the upstream to the downstream of the health care supply chain. We propose a framework, the 3A-framework, that is founded on three constructs,affordability, access, and awareness,to inform the design of supply chain for the health care sector. We present an illustrative example of the framework toward designing the supply chain for implantable device,based care for cardiovascular diseases in developing countries. Specifically, the framework provides a lens for identifying an integrated system of continuous improvement and innovation initiatives relevant to bridging the gap between the demand and supply for high-quality, cost-effective, and timely care. Finally, we delineate directions of future research that are anchored in and follow from the developments documented in the article. [source] Conditional Belonging: Farm Workers and the Cultural Politics of Recognition in ZimbabweDEVELOPMENT AND CHANGE, Issue 1 2008Blair Rutherford ABSTRACT This article examines Zimbabwean land politics and the study of rural interventions, including agrarian reform, more broadly, using the analytical framework of territorialized ,modes of belonging' and their ,cultural politics of recognition'. Modes of belonging are the routinized discourses, social practices and institutional arrangements through which people make claims for resources and rights, the ways through which they become ,incorporated' in particular places. In these spatialized forms of power and authority, particular cultural politics of recognition operate; these are the cultural styles of interaction that become privileged as proper forms of decorum and morality informing dependencies and interdependencies. The author traces a hegemonic mode of belonging identified as ,domestic government', put in place on European farms in Zimbabwe's colonial period, and shows how it was shaped by particular political and economic conjunctures in the first twenty years of Independence after 1980. Domestic government provided a conditional belonging for farm workers in terms of claims to limited resources on commercial farms while positioning them in a way that made them marginal citizens in the nation at large. This is the context for the behaviour of land-giving authorities which have actively discriminated against farm workers during the politicized and violent land redistribution processes that began in 2000. Most former farm workers are now seeking other forms of dependencies, typically more precarious and generating fewer resources and services than they had accessed on commercial farms, with their own particular cultural politics of recognition, often tied to demonstrating support to the ruling political party. [source] Labour market implications of EU product market integrationECONOMIC POLICY, Issue 30 2000Torben M. Andersen European labour markets are in a state of flux due to the changing market situation induced by international integration. This process affects wage formation through more fierce product market competition and increased mobility of jobs. This development is by some observers taken to enforce labour market flexibility, while for others it signals an erosion of social standards and in turn possibly the welfare society. Since labour is not very mobile in Europe, the effects of international integration on labour markets are mostly indirect via product market integration. We review the channels through which product market integration affects labour markets and perform an empirical analysis of the convergence and interdependencies in wage formation among EU countries. We find that integration is changing labour market structures and inducing wage convergences as well as stronger wage interdependencies, but it is a gradual process. Moreover, the present study does not support the view that international integration will lead to a ,race to the bottom' and rapidly erode domestic labour markets standards, nor that it will relieve politicians of the need to consider labour market reforms to improve labour market performance. [source] Strategies of family farms to strengthen their resilienceENVIRONMENTAL POLICY AND GOVERNANCE, Issue 4 2010Ika Darnhofer Abstract Resilience thinking offers a framework to emphasize dynamics and interdependencies across time, space and domains. It is based on understanding social,ecological systems as complex, and future developments as unpredictable, thus emphasizing adaptive approaches to management. In this paper the four clusters of factors that have been identified as building resilience in large-scale social,ecological systems are applied at the farm level. Suggestions on how these factors could be operationalized at the farm level are derived from workshops held with family farmers in Austria. The results show that farmers understand change as unpredictable and unfolding, have a number of strategies to ensure the flexibility and adaptability of their farm and build extensive networks to diversify information and income sources. However, these strategies, while ensuring adaptability and transformability, compete for scarce resources. The farmers thus face trade-offs between strategies that ensure the adaptive capacity of their farm over the long term and those ensuring profitability over the short term. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment. [source] The Impact of Metropolitan Structure on Commute Behavior in the Netherlands: A Multilevel ApproachGROWTH AND CHANGE, Issue 3 2004Tim Schwanen ABSTRACT This paper documents the investigation of the impact of metropolitan structure on the commute behavior of urban residents in the Netherlands. Not only has the impact of monocentrism versus polycentrism been analyzed, but the influence of metropolitan density and size has also been considered, together with the ratio of employment to population and the growth of the population and employment. Furthermore, data are used at a variety of levels of analysis ranging from the individual worker to the metropolitan region rather than being drawn from aggregate level statistics alone. Multilevel regression modeling is applied to take account of the interdependencies among these levels of aggregation. With regard to mode choice, the results indicate that the probability of driving an auto to work is lower in employment-rich metropolitan regions, and rises as the number of jobs per resident has grown strongly. Furthermore, women in most polycentric regions are less likely to commute as an auto driver. All else being equal, commute distances and times for auto drivers are longer in most polycentric regions than in monocentric urban areas. In addition, commute time as an auto driver rises with metropolitan size, whereas commute distance depends on employment density and the growth of the number of jobs per resident. The investigation shows that metropolitan structure, although significantly influencing commute patterns, explains only a small part of the variation of individuals' commute behavior. [source] Climatology of near-surface wind patterns over SwitzerlandINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2001Rudolf O. Weber Abstract Over complex, mountainous terrain the near-surface winds can form intricate patterns as large-scale winds and locally forced wind systems interplay. Switzerland, with its mountainous topography and dense meteorological network of 115 automated surface stations, ideally serves as a study area for such wind system interactions. Applying an automated classification scheme to the wind data of one single year (1995), 16 distinct near-surface flow patterns were found. These patterns also show characteristic distributions in magnitude and areal extent of temperature, global radiation and precipitation. An 18-year climatology of flow patterns was created with an identification method for fewer stations. This allowed the determination of annual and diurnal variations in the frequencies of occurrence of the different flow patterns, revealing pronounced daytime and night-time classes characterized by thermally forced winds. Transition probabilities between the flow patterns were computed as well. The relationship between the near-surface wind patterns and the synoptic flow situation was investigated with a comparison with synoptic weather types defined for the Alpine region. The results show clear but not unequivocal interdependencies between the synoptic weather type and the near-surface flow pattern. Copyright © 2001 Royal Meteorological Society [source] Strategic decision-making in healthcare organizations: it is time to get serious,INTERNATIONAL JOURNAL OF HEALTH PLANNING AND MANAGEMENT, Issue 3 2006David W. Young Abstract New and continuing environmental demands and competitive forces require healthcare organizations to be increasingly careful in thinking about their strategies. They must do so in a highly unusual (multi-actor) marketplace where a variety of system interdependencies complicate decision-making. A good strategy requires an attempt to understand the real, as distinct from the perceived, environment, and is characterized by explicit tradeoffs along three dimensions: service or program variety, patient needs, and patient access. The quality of these tradeoffs can be assessed in terms of whether the strategy is (a) attuned to critical success factors in the organization's environment, (b) highly focused, (c) linked to the organization's capabilities, and (d) accompanied by an activity set that is difficult for competitors to imitate. An organization also must be capable of adapting appropriately to changes in its environment. Thus, even the best strategy must be reviewed constantly if it is to remain viable. A strategy's sustainability can be adversely affected by increased buyer or supplier power, lowered barriers to entry, growing rivalry, the threat of substitutes, and increased slack in resource usage. By thinking more creatively in the future than they have in the past, healthcare organizations can make tradeoffs and choose a focused strategic position. They then can design an activity set that is appropriate for that position, and that will assist them to achieve both financial viability and superior programmatic performance. A well-designed activity set also will assist them to sustain their performance in the face of changing environmental demands and competitive forces. Copyright © 2006 John Wiley & Sons, Ltd. [source] Westphalian Eurocentrism in International Relations TheoryINTERNATIONAL STUDIES REVIEW, Issue 2 2010Turan Kayaoglu In the past 10,15 years, an increasing number of revisionist scholars have rejected the most significant elements of the argument about the centrality of the Peace of Westphalia (1648) to the evolution and structure of international society. At the same time, the prominence of this argument has grown in the English School and constructivist international relations scholarship. I deconstruct the function of the Westphalian narrative to explain its pervasiveness and persistence. I argue that it was first developed by nineteenth century imperial international jurists and that the Westphalian narrative perpetuates a Eurocentric bias in international relations theory. This bias maintains that Westphalia created an international society, consolidating a normative divergence between European international relations and the rest of the international system. This dualism is predicated on the assumption that with Westphalia European states had solved the anarchy problem either through cultural or contractual evolution. Non-European states, lacking this European culture and social contract, remained in anarchy until the European states allowed them to join the international society,upon their achievement of the "standards of civilization." This Westphalian narrative distorts the emergence of the modern international system and leads to misdiagnoses of major problems of contemporary international relations. Furthermore, their commitment to the Westphalian narrative prevents international relations scholars from adequately theorizing about international interdependencies and accommodating global pluralism. [source] Exploring the international linkages of the euro area: a global VAR analysisJOURNAL OF APPLIED ECONOMETRICS, Issue 1 2007Stephane Dees This paper presents a quarterly global model combining individual country vector error-correcting models in which the domestic variables are related to the country-specific foreign variables. The global VAR (GVAR) model is estimated for 26 countries, the euro area being treated as a single economy, over the period 1979,2003. It advances research in this area in a number of directions. In particular, it provides a theoretical framework where the GVAR is derived as an approximation to a global unobserved common factor model. Using average pair-wise cross-section error correlations, the GVAR approach is shown to be quite effective in dealing with the common factor interdependencies and international co-movements of business cycles. It develops a sieve bootstrap procedure for simulation of the GVAR as a whole, which is then used in testing the structural stability of the parameters, and for establishing bootstrap confidence bounds for the impulse responses. Finally, in addition to generalized impulse responses, the current paper considers the use of the GVAR for ,structural' impulse response analysis with focus on external shocks for the euro area economy, particularly in response to shocks to the US. Copyright © 2007 John Wiley & Sons, Ltd. [source] From the Politics of Urgency to the Governance of Preparedness: A Research Agenda on Urban VulnerabilityJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 2 2005Will Medd To date, little social science understanding has been developed about what it would mean to strategically build resilience in the context of such rich interdependencies between social, technical and natural worlds. We argue that shifts in strategies to deal with urban crises marks a turn from the politics of urgency, characteristic of crisis management, towards a governance of preparedness, characterised by strategies to build urban resilience. Social science needs to develop research agendas that critically engage with different understandings of resilience and the challenges of building resilience across different scales of urban governance. [source] The Diffusion of Cricket to America: A Figurational Sociological ExaminationJOURNAL OF HISTORICAL SOCIOLOGY, Issue 2 2006DOMINIC MALCOLM It is argued that class and cricketing relations in England in the mid-nineteenth century had a significant and hitherto unacknowledged impact on the diffusion of the game to America, and that this unplanned social process can only be understood in the light of the specific interdependencies between the British and Anglo-Americans, between upper and lower class English immigrants, and between English immigrants and "Native White Americans". Correlatively, this analysis spreads new light on the establishment of baseball as America's national game, illustrating a greater level of dependence on the English and English sport than is traditionally attributed. [source] Crossing national boundaries: A typology of qualified immigrants' career orientationsJOURNAL OF ORGANIZATIONAL BEHAVIOR, Issue 5 2010Jelena Zikic Abstract This qualitative study examines objective,subjective career interdependencies within a sample of 45 qualified immigrants (QIs) in Canada, Spain and France. The particular challenges in this type of self-initiated international careers arise from the power of institutions and local gatekeepers, the lack of recognition for QIs' foreign career capital, and the need for proactivity. Resulting from primary data analysis, we identify six major themes in QIs' subjective interpretations of objective barriers: Maintaining motivation, managing identity, developing new credentials, developing local know-how, building a new social network and evaluating career success. Secondary data analysis distinguishes three QI career orientations,embracing, adaptive and resisting orientations,with each portraying distinct patterns of motivation, identity and coping. This study extends the boundaryless career perspective by providing a more fine-grained understanding of how qualified migrants manage both physical and psychological mobility during self-initiated international career transitions. With regards to the interdependence between objective and subjective career aspects, it illustrates the importance of avoiding preference to one side at the neglect of the other, or treating the two sides as independent of one another. Practical implications are proposed for career management efforts and receiving economies. Copyright © 2010 John Wiley & Sons, Ltd. [source] Interdependent Preferences and Groups of AgentsJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 1 2001Stanley Reiter An individual's preferences are assumed to be malleable and may be influenced by the preferences of others. Mutual interaction among individuals whose preferences are interdependent powers a dynamic process in which preference profiles evolve over time. Two formulations of the dynamic process are presented. One is an abstract model in which the iteration of a mapping from profiles to profiles defines a discrete time dynamic process; the other is a linear discrete time process specified in more detail. Examples motivate the model and illustrate its application. Conditions are given for the existence of a stable preference profile,a rest point of the dynamic process. A stable profile is naturally associated with a division, not in general unique, of the set of agents into subgroups with the property that preference interdependencies within a subgroup are "stronger" than those across subgroups. The conventional case in which each agent's preference relation is exogenously given is, in this model, the special case where each subgroup consists of just one agent. [source] SLOW CITIES: SUSTAINABLE PLACES IN A FAST WORLDJOURNAL OF URBAN AFFAIRS, Issue 4 2006HEIKE MAYER ABSTRACT:,This article examines the Slow Food and Slow City movement as an alternative approach to urban development that focuses on local resources, economic and cultural strengths, and the unique historical context of a town. Following recent discussions about the politics of alternative economic development, the study examines the Slow City movement as a strategy to address the interdependencies between goals for economic, environmental, and equitable urban development. In particular, we draw on the examples of two Slow Cities in Germany,Waldkirch and Hersbruck, and show how these towns are retooling their urban policies. The study is placed in the context of alternative urban development agendas as opposed to corporate-centered development. We conclude the article by offering some remarks about the institutional and political attributes of successful Slow Cities and the transferability of the concept. [source] Anatomy of a failed knowledge management initiative: lessons from PharmaCorp's experiencesKNOWLEDGE AND PROCESS MANAGEMENT: THE JOURNAL OF CORPORATE TRANSFORMATION, Issue 1 2002Ashley Braganza On a sunny morning in July 1999, Samuel Parsons, Head of Knowledge Management at PharmaCorp, convened his regular Monday team meeting. He looked stressed. After dealing with a couple of administrative issues he said: ,Last Friday evening I was informed that Wilco Smith, Head of Pharma Global Order Handling Services, no longer wants knowledge management. His only question now is how to off-board the knowledge management staff.' Thus came to an end a three-year initiative that at the outset was considered to be ,the knowledge management showcase for the firm'. This paper is for managers who have an interest in operationalizing knowledge and want to avoid the traps others have fallen into. It examines the case of PharmaCorp, a global organization and one of the largest in its industry. The case provides managers with five key lessons. First, manage knowledge interdependencies across communities of practice; second, contextualize knowledge within natural groups of activities; third, avoid an over-emphasis on explicit knowledge; fourth, let knowledge management recipients determine tacit and explicit knowledge; and fifth, manage the input from external consultants. Copyright © 2002 John Wiley & Sons, Ltd. [source] Wer soll für die Schulden im Bundesstaat haften?PERSPEKTIVEN DER WIRTSCHAFTSPOLITIK, Issue 1 2009Eine vernachlässigte Frage der Föderalismusreform II A commission eager to impose stricter debt limits on state budgets encountered opposition by the Länder. This article proposes the strengthening of the Länder liability for their respective debt in order to disentangle interdependencies between state layers. A recent Federal Constitutional Court ruling is analyzed which sharply reduced bailout expectations of Länder and hence allows for the evolution of new institutions such as public bonds with collective action clauses as intermediate institutions towards strict bankruptcy procedures. [source] POLICY-LEARNING AND ENVIRONMENTAL POLICY INTEGRATION IN THE COMMON AGRICULTURAL POLICY, 1973,2003PUBLIC ADMINISTRATION, Issue 2 2010PETER H. FEINDT This article uses the Advocacy Coalition Framework (ACF) (Sabatier and Jenkins-Smith 1999; Weible and Sabatier 2007) and a refined version of the social learning approach of Peter Hall (1993) to assess and explain policy change in the Common (Agricultural) Policy (CAP) with a special view on Environmental Policy Integration (EPI). Three stages of EPI are discerned that move from central to vertical and later horizontal EPI, complementing an impact model of agriculture and the environment with a public goods model. Reform debates appear as prolonged and iterative battles over the institutionalization of new ideas which are finally incorporated into the existing policy framework. The policy network increasingly reflects cross-policy interdependencies and includes superior authorities, rendering the notion of a policy subsystem problematic. Contrary to the social learning model, the major (although not the most radical) change proponent dominates the policy community while superior authorities tend to intervene on behalf of the status quo. The argument is developed on the base of interviews with policy-makers in Brussels. [source] Managing and reporting intangible assets in research technology organisationsR & D MANAGEMENT, Issue 2 2005Karl-Heinz Leitner In the last couple of years, new instruments and methods for measuring, valuing and managing different forms of intangible assets have been proposed. Firms started to implement comprehensive management techniques to identify and value different forms of intangible assets based on an integrative framework, incorporating different forms of intangible assets such as R&D and human capital. Research Technology Organisations (RTOs) present an interesting case for studying different forms of intangible assets, their interdependencies and their impact on outputs. The main business of these organisations is R&D; thus, nearly all forms of investments are related to the R&D process. Their outputs are knowledge-intensive products, services and public goods with the aim of improving the innovation output of their various customers. Some European RTOs have started to introduce new instruments for measuring and managing their intangible assets more explicitly. The paper investigates the general background, a specific model and empirical experiences of an Austrian RTO, which introduced an intellectual capital management system. [source] Figurational dynamics and parliamentary discourses of living standards in Ireland1THE BRITISH JOURNAL OF SOCIOLOGY, Issue 4 2009Paddy Dolan Abstract While the concept of living standards remains central to political debate, it has become marginal in sociological research compared to the burgeoning attention given to the topic of consumer culture in recent decades. However, they both concern how one does and should consume, and, indeed, behave at particular times. I use the theories of Norbert Elias to explain the unplanned but structured (ordered) changes in expected standards of living over time. This figurational approach is compared to other alternative explanations, particularly those advanced by Bourdieu, Veblen and Baudrillard. Though these offer some parallels with Elias's theories, I argue that consumption standards are produced and transformed through the changing dependencies and power relations between social classes. They cannot be reduced to the intentions, interests or ambitions of particular elites, nor to the needs of social systems. Using qualitative data from parliamentary debates in Ireland to trace changing norms and ideals of consumption, as well as historical data to reconstruct shifts in social interdependencies, I further contend that discourses of living standards and luxury are vital aspects of the growing identification and empathy between classes, which in turn encourages greater global integration in the face of emigration and national decline. [source] Interdependencies between agricultural commodity futures prices on the LIFFETHE JOURNAL OF FUTURES MARKETS, Issue 3 2002P. J. Dawson Interdependencies between commodity prices can arise from the impact of changing macroeconomic variables, from complementarities or substitutabilities between commodities, or from common responses by speculators. Malliaris and Urrutia (1996) found significant linkages between rollover prices of six related agricultural commodities on the Chicago Board of Trade. This article examines interdependencies between futures prices for soft commodities traded on the London International Financial Futures Exchange (LIFFE), calculated using Clark indices. Results show that there are no interdependencies between any two prices; price discovery of one contract provides no information about others. © 2002 John Wiley & Sons, Inc. Jrl Fut Mark 22: 269,280, 2002 [source] Interfirm Modularity and Its Implications for Product Development,THE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 4 2005Nancy Staudenmayer Industries characterized by interfirm modularity, in which the component products of different firms work together to create a system, are becoming increasingly widespread. In such industries, the existence of a common architecture enables consumers to mix and match the products of different firms. Industries ranging from stereos, cameras, and bicycles to computers, printing, and wireless services are now characterized by interfirm modularity. While the increasing presence of this context has been documented, the implications for the product development process remain underdeveloped. For the present study, in-depth field-based case studies of seven firms experiencing an environment of interfirm modularity were conducted in order to deepen understanding of this important phenomenon. What unique challenges did this context pose and why? What solutions did firms experiment with, and which seemed to work? Based on an inductive process of data analysis from these case studies, three primary categories of challenges raised by this environment were identified. First, firms were frustrated at their lack of control over the definition of their own products. The set of features and functions in products were constrained to a great extent by an architecture that the firm did not control. Second, while an environment of interfirm modularity should in theory eliminate interdependencies among firms since interfaces between products are defined ex-ante, the present study found, ironically, that interdependencies were ubiquitous. Interdependencies continually emerged throughout the product development process, despite efforts to limit them. Third, firms found that the quantity and variegated nature of external relationships made their management exceedingly difficult. The sheer complexity was daunting, given both the size of the external network as well as the number of ties per external collaborator. Partners with whom control over the architecture was shared often had divergent interests,or at least not fully convergent interests. The solutions to these challenges were creative and in many cases counter to established wisdom. For instance, research has suggested many ways for a firm to influence architectural standards. While the firms in the present sample followed some of this advice, they also focused on a more neglected aspect of architecture,the compliance and testing standards that accompany modules and interfaces. By concentrating their efforts in a different area, even smaller firms in this sample were able to have some influence. Instead of focusing on the elimination of interdependencies, it was found that firms benefited from concentrating on the management of interdependencies as they emerged. Finally, while layers of management and "bureaucracy" are often viewed as unproductive, these firms found that adding structure, through positions such as Relationship Manager, was highly beneficial in handling the coordination and control of a wide range of external relationships. [source] Property rights and western United States water markets,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 1 2009Zachary Donohew This paper addresses water scarcity issues in the American West and examines the allocation of water through the appropriative rights system and the extent markets are used to reallocate water from low- to high-valued uses. The unique physical properties of water make it difficult to bound and measure, which makes defining property rights difficult. Markets are also impeded by disputes over third-party effects due to the interdependencies of water users and complex institutional arrangements that dilute decision-making authority. Analysis of water trading in the western United States indicates that the rate of permanent transfers is increasing over time and urban users are paying higher prices relative to agricultural users. [source] Wissenschaftliche Photographie als visuelle Kultur.BERICHTE ZUR WISSENSCHAFTSGESCHICHTE, Issue 3 2005Die Erforschung und Dokumentation von Spektren Abstract This paper discusses facets of 19th-century scientific photography as a visual culture. The example of spectral research and documentation is particularly well suited, because prismatically diffracted light from the sun or from luminous gases was one of the most frequently examined phenomena of that century. The results were significant not only for physics but also for analytical chemistry and astrophysics. The spectrum also served as an ideal test object for checking the effectiveness of a wide array of photochemically sensitizable surfaces to the various color regions. Scientific photography became the most important experimental technique in the infrared and ultraviolet. H. A. Rowland's spectrum charts are discussed as an example of the transition from comprehensiveness in documentation to fetishism. The discussion of the Lippmann process, one of the first methods of color photography, addresses the associated training of the eye. Issues of authenticity and the much averred ,mechanical objectivity" are raised with regard to retouching. The overriding theme of visual science cultures leads furthermore to unanticipated interdependencies with other scientific fields, such as geography, and draws the importance of practitioners into the foreground. [source] Das Druckgurtmodell für StahlbetonbauteileBETON- UND STAHLBETONBAU, Issue 8 2009Der nachfolgende Beitrag erscheint aus Anlass des 60. Berechnungs- und Bemessungsverfahren; Versuche Abstract In den vergangenen Jahren wurden verschiedene auf die Bemessung von Stahl- und Spannbetonbauteilen ausgerichtete theoretische Modelle entwickelt. Heute stehen das Zuggurtmodell, das Modell der gerissenen (Steg-)Scheibe und das Druckgurtmodell zur Verfügung, auf deren Grundlage Verformungsverhalten und Tragwiderstände umfassend beurteilt werden können. Auf das Druckgurtmodell wird im vorliegenden Beitrag detailliert eingegangen. Es berücksichtigt die Festigkeits- und Duktilitätssteigerung durch eine Umschnürungsbewehrung sowie die bruchmechanisch begründete Entfestigung des Betons und die damit einhergehende Verformungslokalisierung. Auf der Grundlage neuerer Versuchsergebnisse können für die komplexen Interdependenzen zwischen diesen Effekten plausible Beziehungen angegeben werden. Die mithilfe des Druckgurtmodells gewonnenen Erkenntnisse sind für die Baupraxis von Bedeutung: Das Verhalten von auf Druck beanspruchten Bauteilen (z. B. Druckplatten von Brückenquerschnitten, Stützen) lässt sich zuverlässig erfassen; darüber hinaus ergeben sich wichtige Hinweise für die konstruktive Durchbildung. Compression Chord Model for Structural Concrete In recent years, several theoretical models have been developed with the scope on the design of reinforced and prestressed concrete structures. Today, the tension chord model, the cracked membrane model and the compression chord model are available, with which the deformation behaviour as well as ultimate loads can be determined. In the present contribution the compression chord model is discussed in detail. The model takes the increase of strength and ductility due to a confining reinforcement into account and considers the softening as well as the localisation of deformations accompanying the fracture of concrete. On the basis of new test results plausible relations for the complex interdependencies between these effects are found. The results of the compression chord model are relevant for practical applications: The behaviour of compressed members (e.g. in bridge girders or columns) can be assessed reliably; moreover, hints for the detailing of reinforcement can be deduced. [source] Regulation of adult hippocampal neurogenesis , implications for novel theories of major depression1BIPOLAR DISORDERS, Issue 1 2002Gerd Kempermann Major depression, whose biological origins have been difficult to grasp for decades, might result from a disturbance in neuronal plasticity. New theories begin to consider a fundamental role of adult hippocampal neurogenesis in this loss of plasticity. Could depression and other mood disorders therefore be ,stem cell disorders'? In this review, the potential role of adult hippocampal neurogenesis and of neuronal stem or progenitor cells in depression is discussed with regard to those aspects that are brought up by recent research on how adult hippocampal neurogenesis is regulated. What is known about this regulation today are mosaic pieces and indicates that regulation is complex and is modulated on several levels. Accordingly, emphasis is here laid on those regulatory feedback mechanisms and interdependencies that could help to explain how the pathogenic progression from a hypothesized disruptive cause can occur and lead to the complex clinical picture in mood disorders. While the ,neurogenic theory' of depression remains highly speculative today, it might stimulate the generation of sophisticated working hypotheses, useful animal experiments and the first step towards new therapeutic approaches. [source] THE EFFECT OF GOVERNMENT POLICY ON TOBACCO ADVERTISING STRATEGIESBULLETIN OF ECONOMIC RESEARCH, Issue 3 2010Caroline Elliott C32; I18; L66; M37 ABSTRACT This paper contributes to the very limited literature examining the factors determining tobacco companies' advertising strategies. The paper explores whether firms in the UK tobacco market significantly changed their advertising expenditure in the face of proposed changes to the UK and European Commission tobacco advertising legislation. The results suggest that changes in legislation have little impact on firms' advertising strategies for existing brands, but that legislative changes impact upon product launch dates. Our results also offer some information on the nature of firm interdependencies in the UK tobacco industry. [source] Constraints on the conversion to sustainable production: the case of the Dutch potato chainBUSINESS STRATEGY AND THE ENVIRONMENT, Issue 6 2008A. A. H. (Arnoud) Smit Abstract The question of how to make agriculture more sustainable is a timely topic. This paper examines the Dutch potato supply chain in the context of its surrounding network. Based on the chain network approach it identifies constraints on conversion to organic potato production from a business administration and a public administration perspective. Two obvious constraints are the demand for ecologically produced products and the problem of cultivating potatoes. However, the potential for conversion is also affected by the way the market and the supply chain are structured, by the coordination of activities, efficiency-driven actors, relations and interdependencies between actors and by the asymmetrical distribution of power. Furthermore, conversion is constrained by the limited influence of network parties such as NGOs and current government policies. Based on the analysis, the paper questions whether the ecological approach (organic farming) will be more effective than strengthening a more generic approach stimulating the sustainability of the sector. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment. [source] Organizational sticking points on NK LandscapesCOMPLEXITY, Issue 5 2002Jan W. Rivkin Abstract Scholars studying human organizations have recently adopted the notion of fitness landscapes, a concept pioneered in the biological and physical sciences. Such scholars have generally assumed that organizations will migrate toward the local peaks of these landscapes, as biological and physical entities do. We use an agent-based simulation to show, to the contrary, that a hierarchical human organization may very well come to rest at a "sticking point" that is not a local peak on the fitness landscape of the overall organization. Three pervasive features of human organizations create the distinction between sticking points and local peaks: the delegation of choices to separate decision makers, interdependencies between the domains of those decision makers, and differences between local incentives and global incentives. Our results illustrate both that it is valuable to use tools developed to study one type of complex adaptive system in order to examine another type and that researchers must adapt the tools with care as they attempt to do so. © 2002 Wiley Periodicals, Inc. [source] Targeted cell-ablation in Xenopus embryos using the conditional, toxic viral protein M2(H37A)DEVELOPMENTAL DYNAMICS, Issue 8 2007Stuart J. Smith Abstract Harnessing toxic proteins to destroy selective cells in an embryo is an attractive method for exploring details of cell fate and cell,cell interdependency. However, no existing "suicide gene" system has proved suitable for aquatic vertebrates. We use the M2(H37A) toxic ion channel of the influenza-A virus to induce cell-ablations in Xenopus laevis. M2(H37A) RNA injected into blastomeres of early stage embryos causes death of their progeny by late-blastula stages. Moreover, M2(H37A) toxicity can be controlled using the M2 inhibitor rimantadine. We have tested the ablation system using transgenesis to target M2(H37A) expression to selected cells in the embryo. Using the myocardial MLC2 promoter, M2(H37A)-mediated cell death causes dramatic loss of cardiac structure and function by stage 39. With the LURP1 promoter, we induce cell-ablations of macrophages. These experiments demonstrate the effectiveness of M2(H37A)-ablation in Xenopus and its utility in monitoring the progression of developmental abnormalities during targeted cell death experiments. Developmental Dynamics 236:2159,2171, 2007. © 2007 Wiley-Liss, Inc. [source] Biodegradable Polymer Crosslinker: Independent Control of Stiffness, Toughness, and Hydrogel Degradation RateADVANCED FUNCTIONAL MATERIALS, Issue 19 2009Chaenyung Cha Abstract Hydrogels are being increasingly studied for use in various biomedical applications including drug delivery and tissue engineering. The successful use of a hydrogel in these applications greatly relies on a refined control of the mechanical properties including stiffness, toughness, and the degradation rate. However, it is still challenging to control the hydrogel properties in an independent manner due to the interdependency between hydrogel properties. Here it is hypothesized that a biodegradable polymeric crosslinker would allow for decoupling of the dependency between the properties of various hydrogel materials. This hypothesis is examined using oxidized methacrylic alginate (OMA). The OMA is synthesized by partially oxidizing alginate to generate hydrolytically labile units and conjugating methacrylic groups. It is used to crosslink poly(ethylene glycol) methacrylate and poly(N -hydroxymethyl acrylamide) to form three-dimensional hydrogel systems. OMA significantly improves rigidity and toughness of both hydrogels as compared with a small molecule crosslinker, and also controls the degradation rate of hydrogels depending on the oxidation degree, without altering their initial mechanical properties. The protein-release rate from a hydrogel and subsequent angiogenesis in vivo are thus regulated with the chemical structure of OMA. Overall, the results of this study suggests that the use of OMA as a crosslinker will allow the implantation of a hydrogel in tissue subject to an external mechanical loading with a desired protein-release profile. The OMA synthesized in this study will be, therefore, highly useful to independently control the mechanical properties and degradation rate of a wide array of hydrogels. [source] | |||||||||||||||||||||||||||||||||||||