4,379 research outputs found

    Run-Time Selection of Coordination Mechanisms in Multi-Agent Systems

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    This paper presents a framework that enables autonomous agents to dynamically select the mechanism they employ in order to coordinate their inter-related activities. Adopting this framework means coordination mechanisms move from the realm of being imposed upon the system at design time, to something that the agents select at run-time in order to fit their prevailing circumstances and their current coordination needs. Empirical analysis is used to evaluate the effect of various design alternatives for the agent's decision making mechanisms and for the coordination mechanisms themselves

    Protein and DNA sequence determinants of thermophilic adaptation

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    Prokaryotes living at extreme environmental temperatures exhibit pronounced signatures in the amino acid composition of their proteins and nucleotide compositions of their genomes reflective of adaptation to their thermal environments. However, despite significant efforts, the definitive answer of what are the genomic and proteomic compositional determinants of Optimal Growth Temperature of prokaryotic organisms remained elusive. Here the authors performed a comprehensive analysis of amino acid and nucleotide compositional signatures of thermophylic adaptation by exhaustively evaluating all combinations of amino acids and nucleotides as possible determinants of Optimal Growth Temperature for all prokaryotic organisms with fully sequences genomes.. The authors discovered that total concentration of seven amino acids in proteomes, IVYWREL, serves as a universal proteomic predictor of Optimal Growth Temperature in prokaryotes. Resolving the old-standing controversy the authors determined that the variation in nucleotide composition (increase of purine load, or A+G content with temperature) is largely a consequence of thermal adaptation of proteins. However, the frequency with which A and G nucleotides appear as nearest neighbors in genome sequences is strongly and independently correlated with Optimal Growth Temperature. as a result of codon bias in corresponding genomes. Together these results provide a complete picture of proteomic and genomic determinants of thermophilic adaptation.Comment: in press PLoS Computational Biology; revised versio

    Implementation principles - turning intentions into outcomes

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    Companies sometimes fail to take effective action even when they know what they should do. Recent research shows that this surprising situation is more common than one would expect. How can the track record of companies in achieving the outcomes targeted by manufacturing strategy be improved? This article proposes a set of eight principles to improve the chances of taking effective action to turn intentions into outcomes. Rooted in the literature, the principles have also surfaced in case based research and commented on in the context of international consulting activities

    Food hygiene and sanitation in infants and young children: A paediatric food-based dietary guideline

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    This paper has three related aims. Firstly, it aims to profile the current food hygiene and safety needs of children under the age of five in South Africa. Secondly, to reflect the importance of domestic hygiene, access to water and sanitation in reducing the transmission of gastrointestinal pathogens while feeding infants and young children. And, thirdly, to highlight the need for collaboration between healthcare professionals and the local authorities who provide basic services. Food safety and hygiene needs for people living with HIV/AIDS (PLWHA) have been mainstreamed in the various sections addressed in this paper that underpin the  importance of food safety and hygiene in immune-compromised  individuals. The following topics have been covered: water and sanitation, food safety and hygiene, hand washing and personal hygiene, hygiene and sanitation for PLWHA, relevant primary healthcare strategies (e.g. oral rehydration solutions), rotavirus immunisation, and vitamin A and zinc supplementation. Additionally, the paper discusses relevant interventions to prevent diarrhoeal disease. This review utilises sourced references in both global and local evidence-based studies by conducting repeated literature searches via PubMed, the Cochrane Collaboration, Google Scholar, EBSCO Information Services and United Nations’ agency  documents, as well as the “grey” literature (theses, research reports and other nonindexed material). The main keywords “hygiene”, “sanitation”, “infants” and “young children” were used, in addition to other keywords and key phrases referred to in the text. On the basis of the literature review, it is proposed that the following message is tested for inclusion in the food-based dietary guidelines for infants and young children: “Hands should be washed with clean water and soap before preparing, feeding or eating, and after going to the toilet”

    Exact vortex nucleation and cooperative vortex tunneling in dilute BECs

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    With the imminent advent of mesoscopic rotating BECs in the lowest Landau level (LLL) regime, we explore LLL vortex nucleation. An exact many-body analysis is presented in a weakly elliptical trap for up to 400 particles. Striking non-mean field features are exposed at filling factors >>1 . Eg near the critical rotation frequency pairs of energy levels approach each other with exponential accuracy. A physical interpretation is provided by requantising a mean field theory, where 1/N plays the role of Planck's constant, revealing two vortices cooperatively tunneling between classically degenerate energy minima. The tunnel splitting variation is described in terms of frequency, particle number and ellipticity.Comment: 4 pages,4 figure

    Racial and Ethnic Differences in Falls Among Older Adults: a Systematic Review and Meta-analysis

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    The aim of this systematic review and meta-analysis was to determine whether differences in reported fall rates exist between different ethnic groups. Searches were carried out on four databases: Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Web of Science. Only English language studies with community-dwelling participants aged 60 + years were included. Studies also needed to compare fall prevalence for at least two or more ethnic groups. Two reviewers independently screened all articles and evaluated study quality. Twenty-three articles were included for systematic review, and meta-analyses were carried out on the 16 retrospective studies that reported falls in the previous 12 months. The Asian group demonstrated significantly lower fall prevalence than all other ethnic groups at 13.89% (10.87, 16.91). The Hispanic group had a fall prevalence of 18.54% (12.95, 24.13), closely followed by the Black group at 18.60% (13.27, 23.93). The White group had the highest prevalence at 23.77% (18.66, 28.88). Some studies provided adjusted estimates of effect statistics for the odds/risk of falls, which showed that differences still existed between some ethnic groups even after adjusting for other risk factors. Overall, differences in fall prevalence do appear to exist between different ethnic groups, although the reasons for these differences currently remain undetermined and require further investigation. These findings highlight the need to provide more ethnically tailored responses to public health challenges, which could potentially increase the adherence to prevention interventions, and allow for a more targeted use of resources

    Anomalous hydrodynamics and "normal" fluids in rapidly rotating BECs

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    In rapidly rotating bose systems we show that there is a region of anomalous hydrodynamics whilst the system is still condensed, which coincides with the mean field quantum Hall regime. An immediate consequence is the absence of a normal fluid in any conventional sense. However, even the superfluid hydrodynamics is not described by conventional Bernoulli and continuity equations. We show there are kinematic constraints which connect spatial variations of density and phase, that the positions of vortices are not the simplest description of the dynamics of such a fluid (despite their utility in describing the instantaneous state of the condensate) and that the most compact description allows solution of some illuminating examples of motion. We demonstrate, inter alia, a very simple relation between vortices and surface waves. We show the surface waves can form a "normal fluid" which absorbs energy and angular momentum from vortex motion in the trap. The time scale of this process is sensitive to the initial configuration of the vortices, which can lead to long-lived vortex patches - perhaps related to those observed at JILA.Comment: 4 pages; 1 sentence and references modifie

    T-PHOT version 2.0: improved algorithms for background subtraction, local convolution, kernel registration, and new options

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    We present the new release v2.0 of T-PHOT, a publicly available software package developed to perform PSF-matched, prior-based, multiwavelength deconfusion photometry of extragalactic fields. New features included in the code are presented and discussed: background estimation, fitting using position dependent kernels, flux prioring, diagnostical statistics on the residual image, exclusion of selected sources from the model and residual images, individual registration of fitted objects. These new options improve on the performance of the code, allowing for more accurate results and providing useful aids for diagnostics.Comment: 7 pages, 8 figure
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