6,950 research outputs found

    Local ciliate communities associated with aquatic macrophytes

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    This study, based within the catchment area of the River Frome, an important chalk stream in the south of England, compared ciliated protozoan communities associated with three species of aquatic macrophyte common to lotic habitats: Ranunculus penicillatus subsp. pseudofluitans, Nasturtium officinale and Sparganium emersum. A total of 77 ciliate species were counted. No species-specific ciliate assemblage was found to be typical of any one plant species. Ciliate abundance between plant species was determined to be significantly different. The ciliate communities from each plant species were unique in that the number of species increased with ciliate abundance. The community associated with R. penicillatus subsp. pseudofluitans showed the highest consistency and species richness whereas S. emersum ciliate communities were unstable. Most notably, N. officinale was associated with low ciliate abundances and an apparent reduction in biofilm formation, discussed herein in relation to the plant’s production of the microbial toxin phenethyl isothiocyanate. We propose that the results reflect differences in the quantity and quality of biofilm present on the plants, which could be determined by the different plant morphologies, patterns of plant decay and herbivore defense systems, all of which suppress or promote the various conditions for biofilm growth

    International healthcare worker migration in Asia Pacific: International policy responses

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    The growth of the international migration of health workers in recent decades has taken place in the context of the transnationalisation of healthcare provision as well as of governance and policy responses. This paper examines international policy responses to cross-border health worker migration in the Asia Pacific region. These include multilateral (global and regional) and bilateral policy agreements, policy dialogue and programmes of action in relation to key issues of ethical recruitment, ‘circular’ migration and labour rights and key themes of health workforce planning and management. The paper brings original new analysis of international datasets and secondary data to bear on the pressing and important questions of what international policy initiatives and responses are at work in the Asia Pacific region, and what these mean for the nature of migration governance in the region. The paper's focus routes the evidence and argument towards current research and policy debates about the relationship between health worker migration, health worker shortages and poor health outcomes. In this, the paper brings new insights into the analysis of the international policy ‘universe’ through its emphasis on multiple and intersecting cross-border institutions, initiatives and actors operating across different scales. Coherent national and international strategies for integrated health worker migration governance and policy need to incorporate these insights, and the paper considers their implications for current strategies to attain universal health care and improved health outcomes in Asia Pacific and beyond

    Coronal mass ejection initiation: On the nature of the Flux Cancellation Model

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    We consider a three-dimensional bipolar force-free magnetic field with non zero magnetic helicity, occupying a half-space, and study the problem of its evolution driven by an imposed photospheric flux decrease. For this specific setting of the Flux Cancellation Model describing coronal mass ejections occuring in active regions, we address the issues of the physical meaning of flux decrease, of the influence on field evolution of the size of the domain over which this decrease is imposed, and of the existence of an energetic criterion characterizing the possible onset of disruption of the configuration. We show that: (1) The imposed flux disappearance can be interpreted in terms of transport of positive and negative fluxes towards the inversion line, where they get annihilated. (2) For the particular case actually computed, in which the initial state is quite sheared, the formation of a twisted flux rope and the subsequent global disruption of the configuration are obtained when the flux has decreased by only a modest amount over a limited part of the whole active region. (3) The disruption is produced when the magnetic energy becomes of the order of the decreasing energy of a semi-open field, and then before reaching the energy of the associated fully open field. This suggests that the mechanism leading to the disruption is nonequilibrium as in the case where flux is imposed to decrease over the whole region.Comment: In press in ApJ Letter

    Using compression to identify acronyms in text

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    Text mining is about looking for patterns in natural language text, and may be defined as the process of analyzing text to extract information from it for particular purposes. In previous work, we claimed that compression is a key technology for text mining, and backed this up with a study that showed how particular kinds of lexical tokens---names, dates, locations, etc.---can be identified and located in running text, using compression models to provide the leverage necessary to distinguish different token types (Witten et al., 1999)Comment: 10 pages. A short form published in DCC200

    Introduction – Managing Welfare Expectations and Social Change: Policy Responses in Asia

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    The question whether Asian welfare types can be classified as distinctly ‘productivist’ has remained subject to lively debates: in East Asia, the recent implementation of social rights-based public policy innovations – including working family support – as a response to rising inequalities, welfare expectations and accelerating social change has been well documented; similarly, South East Asian and South Asian economies have featured much more frequently in comparative social policy analysis as policymakers have sought to address persisting chronic poverty, a diminishing demographic dividend and burdensome epidemiological transitions via integrating human capital formation with social protection measures. Yet, far from a unifying convergence of these social policy trends in the post-Millennium Development Goals era, the global perspective we take in this article suggests continued variation and difference, with a multiplicity of forms of globalizations encountered and/or engendered in diverse contexts. As a consequence, variegated and path-dependent patterns of social development continue to persist across Asian economies. These findings, in turn, address major issues of our time, for they speak to the broader question of what analytical bases and research strategies can best reveal the complexities of (and interactions between) national, extra-national and transnational drivers of welfare formation and development under contemporary but diverse conditions
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