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General Implications (general + implication)
Selected AbstractsStrength of asymmetric competition between predators in food webs ruled by fluctuating prey: the case of foxes in tundraOIKOS, Issue 1 2010John-André Henden In food webs heavily influenced by multi-annual population fluctuations of key herbivores, predator species may differ in their functional and numerical responses as well as their competitive ability. Focusing on red and arctic fox in tundra with cyclic populations of rodents as key prey, we develop a model to predict how population dynamics of a dominant and versatile predator (red fox) impacted long-term growth rate of a subdominant and less versatile predator (arctic fox). We compare three realistic scenarios of red fox performance: (1) a numerical response scenario where red fox acted as a resident rodent specialist exhibiting population cycles lagging one year after the rodent cycle, (2) an aggregative response scenario where red fox shifted between tundra and a nearby ecosystem (i.e. boreal forest) so as to track rodent peaks in tundra without delay, and (3) a constant subsidy scenario in which the red fox population was stabilized at the same mean density as in the other two scenarios. For all three scenarios it is assumed that the arctic fox responded numerically as a rodent specialist and that the mechanisms of competition is of a interference type for space, in which the arctic fox is excluded from the most resource rich patches in tundra. Arctic fox is impacted most by the constant subsidy scenario and least by the numerical response scenario. The differential effects of the scenarios stemmed from cyclic phase-dependent sensitivity to competition mediated by changes in temporal mean and variance of available prey to the subdominant predator. A general implication from our result is that external resource subsidies (prey or habitats), monopolized by the dominant competitor, can significantly reduce the likelihood for co-existence within the predator guild. In terms of conservation of vulnerable arctic fox populations this means that the likelihood of extinction increases with increasing amount of subsidies (e.g. carcasses of large herbivores or marine resources) in tundra and nearby forest areas, since it will act to both increase and stabilize populations of red fox. [source] The Schengen Law: A Challenge for Legal Accountability in the European UnionEUROPEAN LAW JOURNAL, Issue 2 2002Daniel Thym This article examines challenges for accountability arising from the development of the Schengen law within the framework of the European Union. Building upon the substantive body of research by other authors on general implications of the integration of the Schengen acquis, it focuses on recent developments after the entry into force of the Treaty of Amsterdam and evaluates to what extent the European institutions have so far met the challenges for accountability stemming from the intergovernmental origin of the Schengen law. The article identifies various persisting deficiencies in the areas of transparency, institutional balance and judicial review and proposes specific actions, which should be addressed vigorously by the European institutions. [source] ORIGINAL ARTICLE: Potential for anthropogenic disturbances to influence evolutionary change in the life history of a threatened salmonidEVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 2 2008John G. Williams Abstract Although evolutionary change within most species is thought to occur slowly, recent studies have identified cases where evolutionary change has apparently occurred over a few generations. Anthropogenically altered environments appear particularly open to rapid evolutionary change over comparatively short time scales. Here, we consider a Pacific salmon population that may have experienced life-history evolution, in response to habitat alteration, within a few generations. Historically, juvenile fall Chinook salmon (Oncorhynchus tshawytscha) from the Snake River migrated as subyearlings to the ocean. With changed riverine conditions that resulted from hydropower dam construction, some juveniles now migrate as yearlings, but more interestingly, the yearling migration tactic has made a large contribution to adult returns over the last decade. Optimal life-history models suggest that yearling juvenile migrants currently have a higher fitness than subyearling migrants. Although phenotypic plasticity likely accounts for some of the change in migration tactics, we suggest that evolution also plays a significant role. Evolutionary change prompted by anthropogenic alterations to the environment has general implications for the recovery of endangered species. The case study we present herein illustrates the importance of integrating evolutionary considerations into conservation planning for species at risk. [source] Contemporary Models of Youth Development and Problem Prevention: Toward an Integration of Terms, Concepts, and ModelsFAMILY RELATIONS, Issue 1 2004Stephen Small Over the past several years, increased interest in preventing youth problems and promoting healthy youth development has led youth and family practitioners, policy makers, and researchers to develop a wide range of approaches based on various theoretical frameworks. Although the growth in guiding frameworks has led to more complex models and a greater diversity in the options available to scholars and practitioners, the lack of an integrative conceptual scheme and consistent terminology has led to some confusion in the field. Here, we provide an overview of three approaches to youth development and problem prevention, critically examine their strengths and weaknesses, and offer some elaborations to help clarify, extend, and integrate the models. We conclude by discussing some general implications for researchers, practitioners, and policy makers. [source] Lability of organic carbon in lakes of different trophic statusFRESHWATER BIOLOGY, Issue 6 2009A. P. OSTAPENIA Summary 1. We used first-order kinetic parameters of biological oxygen demand (BOD), the constant of aerobic decomposition (k) and the asymptotic value of BOD (BODult), to characterise the lability of organic carbon pools in six lakes of different trophic state: L. Naroch, L. Miastro and L. Batorino (Belarus), L. Kinneret (Israel), L. Ladoga (Russia) and L. Mendota (U.S.A.). The relative contributions of labile and refractory organic carbon fractions to the pool of total organic carbon (TOC) in these lakes were quantified. We also determined the amounts of labile organic carbon within the dissolved and particulate TOC pools in the three Belarus lakes. 2. Mean annual chlorophyll concentrations (used as a proxy for lake trophic state) ranged from 2.3 to 50.6 ,g L,1, labile organic carbon (OCL = 0.3BODult) from 0.75 to 2.95 mg C L,1 and k from 0.044 to 0.14 day,1. 3. Our data showed that there were greater concentrations of OCL but lower k values in more productive lakes. 4. In all cases, the DOC fraction dominated the TOC pool. OCL was a minor component of the TOC pool averaging about 20%, irrespective of lake trophic state. 5. In all the lakes, most (c. 85%) of the DOC pool was refractory, corresponding with published data based on measurements of bacterial production and DOC depletion. In contrast, a larger fraction (27,55%) of the particulate organic carbon (POC) pool was labile. The relative amount of POC in the TOC pool tended to increase with increasing lake productivity. 6. Long-term BOD incubations can be valuable in quantifying the rates of breakdown of the combined particulate and dissolved organic carbon pools and in characterising the relative proportions of the labile and recalcitrant fractions of these pools. If verified from a larger number of lakes our results could have important general implications. [source] Spaces of Work and Everyday Life: Labour Geographies and the Agency of Unorganised Temporary Migrant WorkersGEOGRAPHY COMPASS (ELECTRONIC), Issue 6 2009Ben Rogaly In this study, I focus on the agency of unorganised temporary migrant workers , people who travel away to work for just a few weeks or months. Such workers have been relatively neglected in labour geography. Perhaps surprisingly, given the focus on the agency of capital in much of his writing, I build on two arguments made by David Harvey. First, workers' spatial mobility is complex and may involve short as well as longer term migrations, and secondly that this can have significance both materially and in relation to the subjective experience of employment. The spatial embeddedness of temporary migrant workers' everyday lives can be a resource for shaping landscapes (and ordinary histories) of capitalism, even though any changes may be short-lived and take place at the micro-scale. The article is illustrated with case study material from research with workers in the agriculture sector in India and the UK, and concludes with more general implications for labour geographers engaged with other sectors and places. [source] Examining and Explaining the Northern League's ,U-Turn' from EuropeGOVERNMENT AND OPPOSITION, Issue 3 2004Raj S. Chari Set in the context of the larger literature on regionalist parties and specifically on the Italian Northern League, this paper examines and explains why the party moved from Euro-positivism to Euroscepticism. Drawing on concepts raised in the larger comparative politics literature, five explanations of this U-turn towards Europe are evaluated. It is argued that, despite the strength of explanations that focus on the desires of party supporters, the role of public opinion, the potential influence of economic investors or the role of EU-level institutions in shaping party preferences, a more cogent explanation focuses on domestic-level developments. The conclusions will underscore the general implications of this research for the study of parties, particularly regionalist ones in the EU, highlighting that a party's changing stance towards supranational integrationist polices can be best understood as a consequence of its experience in a political system's electoral system. [source] Family policy and social order , comparing the dynamics of family policy-making in Scandinavia and Confucian AsiaINTERNATIONAL JOURNAL OF SOCIAL WELFARE, Issue 1 2003Ka Lin This article compares family policies in two Scandinavian and three Confucian Asian countries. Through a general survey on schemes of child allowance and parental leave, it seeks explaining factors for cross-regime diversity of the welfare systems. In focus are the agents affecting the family policy-making process, including social classes, the state, women and families. In order to assess the roles these agents have played, this study retraces the preconditions of family policy development and its associated socio-cultural backgrounds. Results from such an examination will illustrate how the social order determines the patterns of family policy, which offers a new path to travel to these different cultural ,worlds'. Taking the Confucian Asian states into its frame of reference, the study will take a fresh look at Scandinavian welfare systems, which still have some general implications for the study of the dynamics, model and outcome of family policy in an international context. [source] Threads from the labyrinth: therapy with survivors of war and political oppressionJOURNAL OF FAMILY THERAPY, Issue 2 2001Jeremy Woodcock War and political atrocity are endemic, and the denial of what has befallen survivors who become refugees has both therapeutic and human rights dimensions. The work described in this article considers the psychological and political aspects of the suppression of memory and culture and how psychotherapy engages with these processes. Narrative, in its customary form as the creation of stories, is discussed as one of the ways of enabling survivors to be given a voice that allows them to process events of atrocity, displacement and exile. The usefulness of psychoanalytic ideas and their integration with systemic practice is demonstrated. The interplay between difficult psychotherapeutic material, the patient or family and the therapist is shown and the use of supervision noted. The discussion is exemplified with descriptions of therapeutic work with individuals, families and small groups. The thinking that emerges is applicable not only to work with survivors but has general implications for systemic work in general as it struggles with its contemporary identity. [source] ORGANIZATIONAL AND OCCUPATIONAL COMMITMENT: KNOWLEDGE WORKERS IN LARGE CORPORATIONS*JOURNAL OF MANAGEMENT STUDIES, Issue 6 2002TAM YEUK-MUI MAY Previous discussion of knowledge work and workers tends to overlook the importance of contextual knowledge in shaping the organizational form of knowledge workers who are employees in large corporations. This paper proposes a model to understand the way knowledge base and organizational form are related to the work commitment, effort and job satisfaction of knowledge workers. The model is derived from (1) a critical examination of the market model of knowledge work organization, and (2) the results of empirical research conducted in two large corporations. We argue that contextual knowledge is important in the relationships between the corporation and knowledge workers. A dualistic model and an enclave organizational form are suggested to examine the relationships between the commitment, work effort and job satisfaction of knowledge workers. We noted from our empirical cases that enclave-like work teams enhanced the expertise and job autonomy of knowledge workers vis-ŕ-vis management. These work teams together with the performance-based pay system, however, led to unmet job expectations including limited employee influence over decision-making and careers, and communication gaps with senior management. Under these circumstances, and in contrast to the impact of occupational commitment, organizational commitment did not contribute to work effort. The study highlights the importance of management's strategy in shaping the organizational form of knowledge work. The paper concludes by noting general implications of our study for the management of expertise and for further research. [source] Legal and Illegal Production and Trade Under Monopoly with Transaction CostMETROECONOMICA, Issue 3 2000Amit Bhaduri Using illegal trade in narcotics as an example, where regular seizure of part of the merchandise by the law-enforcing authorities imposes a transaction cost on the monopolist supplier, this paper demonstrates the result that a higher transaction cost might increase the volume supplied for trade. The result of the formal model also applies to the opposite situation, e.g. when trade is legal, as in seventeenth- and eighteenth-century maritime trade, but pirates illegally seize part of the merchandise to impose a transaction cost on the traders. The more general implications of this analysis are also discussed. [source] Extreme population subdivision throughout a continuous range: phylogeography of Batrachoseps attenuatus (Caudata: Plethodontidae) in western North AmericaMOLECULAR ECOLOGY, Issue 20 2007IŃIGO MARTÍNEZ, SOLANO Abstract Low-vagility species with deep evolutionary histories are key to our understanding of the biogeographical history of geologically complex areas, such as the west coast of North America. We present a detailed study of the phylogeography of the salamander Batrachoseps attenuatus (Caudata: Plethodontidae) using sequences of the mitochondrial gene cob from 178 individuals sampled from throughout the species' range. Sequences of three other mitochondrial genes (16S, cox1, nad4) and a nuclear gene (RAG-1) were used to investigate the deeper evolutionary history of the species. We found high levels of genetic diversity and deep divergences within a mostly continuous distribution, with five genetically well-differentiated and geographically structured mitochondrial DNA clades. Significant association between geographical and genetic distances within these clades suggests demographic stability, whereas Fu's FS tests suggest demographic expansions in three of them. Mantel tests identify two biogeographical barriers, the San Andreas Fault and the Sacramento,San Joaquin Delta, as important in the diversification of lineages. The timing of the main splitting events between intraspecific lineages was estimated by applying relaxed molecular clock methods combining several mutation rates and a fossil calibration. The earliest splitting events are old (Pliocene/Miocene), with more recent (Pleistocene) subdivisions in some clades. Disjunct populations distributed along the western foothills of the Sierra Nevada colonized this area relatively recently from a single refugium east of San Francisco Bay. The combination of fine-scale, comprehensive sampling with phylogenetic, historical demographic and hypothesis-based tests allowed delineation of a complex biogeographical scenario with general implications for the study of codistributed taxa. [source] Evaluation of quality of life, and priorities in people with glaucomaACTA OPHTHALMOLOGICA, Issue 2009P ASPINALL Purpose Quality of life appears to be of increasing importance as a criterion for clinical intervention. However its meaning can be complex and its assessment varied. In social science the term has broad definitions which include terms such as autonomy, wellbeing; self esteem; sense of control etc. On the other hand within ophthalmology a narrower operational definition is mainly used which is the degree to which someone's vision impacts on a range of necessary and desirable daily tasks a person wishes to carry out. The purpose of the presentation is to compare alternative methods of quality of life assessment. Methods The assessment approaches taken in the study range from conventional questionnaire rating scales, (something NICE has questioned) and time trade off comparisons, to more recent methods of scaling generated by for example Rasch or Hierarchical Bayesian analysis. Results Data will be presented from two studies (one in Edinburgh and one in Aberdeen) on quality of life in people with glaucoma. One of the new recommended discrete choice methods (Choice based conjoint analysis with Hierarchical Bayesian estimates) will be used. The results will include quality of life outcomes and their stability; related visual factors; comparisons across methods and more general implications for quality of life assessment. Conclusion Different methods for the assessment of quality of life produce different results with relatively low correlations between them although conjoint analysis has revealed stable priorities across two independent studies. These discrepancies in quality of life assessment require further study and evaluation. [source] | ||||||||||||||||