55,919 research outputs found

    Artisans and the Marketing of Ethnicity: Globalization, Indigenous Identity and Nobility Principle In Micro-Enterprise Development

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    As a constructed category of human difference, \u27ethnicity\u27 has given way to \u27culture\u27 in its shared genealogy in the new millennium. Public knowledge about such phenomena as \u27ethnic cleansing\u27, debates on immigration, and the use of ethnicity as both a dependent and independent variable in research and policy are central realities in the domestic and foreign policies of many nations. The social psychology of group affiliation, nationalism, and the use of ethnicity (as well as gender) in workplace diversity, or the deployment of ethnicity in electoral politics continues to perplex and complicate human social interaction

    Poor care and the professional duty of the registered nurse

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    Concerns have been raised in recent years about standards of care in the UK. Notable failures have been identified in the care of vulnerable older adults. This article identifies and discusses some logical steps which might be taken to minimise the risk of individual and systemic care failure in settings for older adults. These steps include frank discussion about ageism to promote empowerment and respect for older people; ensuring robust policies are in place that support and encourage the reporting of poor care; and ensuring that registered practitioners are aware of their accountability for their actions and also their omissions should they witness poor care. In addition to reducing the risk of poor care, these steps could contribute to having a more confident, competent and empowered workforce

    Decay dynamics in the coupled-dipole model

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    Cooperative scattering in cold atoms has gained renewed interest, in particular in the context of single-photon superradiance, with the recent experimental observation of super-and subradiance in dilute atomic clouds. Numerical simulations to support experimental signatures of cooperative scattering are often limited by the number of dipoles which can be treated, well below the number of atoms in the experiments. In this paper, we provide systematic numerical studies aimed at matching the regime of dilute atomic clouds. We use a scalar coupled-dipole model in the low excitation limit and an exclusion volume to avoid density-related effects. Scaling laws for super-and subradiance are obtained and the limits of numerical studies are pointed out. We also illustrate the cooperative nature of light scattering by considering an incident laser field, where half of the beam has a π\pi phase shift. The enhanced subradiance obtained under such condition provides an additional signature of the role of coherence in the detected signal

    Effects of neutral selection on the evolution of molecular species

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    We introduce a new model of evolution on a fitness landscape possessing a tunable degree of neutrality. The model allows us to study the general properties of molecular species undergoing neutral evolution. We find that a number of phenomena seen in RNA sequence-structure maps are present also in our general model. Examples are the occurrence of "common" structures which occupy a fraction of the genotype space which tends to unity as the length of the genotype increases, and the formation of percolating neutral networks which cover the genotype space in such a way that a member of such a network can be found within a small radius of any point in the space. We also describe a number of new phenomena which appear to be general properties of neutrally evolving systems. In particular, we show that the maximum fitness attained during the adaptive walk of a population evolving on such a fitness landscape increases with increasing degree of neutrality, and is directly related to the fitness of the most fit percolating network.Comment: 16 pages including 4 postscript figures, typeset in LaTeX2e using the Elsevier macro package elsart.cl

    Quantum query complexity of minor-closed graph properties

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    We study the quantum query complexity of minor-closed graph properties, which include such problems as determining whether an nn-vertex graph is planar, is a forest, or does not contain a path of a given length. We show that most minor-closed properties---those that cannot be characterized by a finite set of forbidden subgraphs---have quantum query complexity \Theta(n^{3/2}). To establish this, we prove an adversary lower bound using a detailed analysis of the structure of minor-closed properties with respect to forbidden topological minors and forbidden subgraphs. On the other hand, we show that minor-closed properties (and more generally, sparse graph properties) that can be characterized by finitely many forbidden subgraphs can be solved strictly faster, in o(n^{3/2}) queries. Our algorithms are a novel application of the quantum walk search framework and give improved upper bounds for several subgraph-finding problems.Comment: v1: 25 pages, 2 figures. v2: 26 page
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