1,169 research outputs found

    Anisotropic creep model for soft soils

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    In this paper a new anisotropic model for time-dependent behaviour of soft soils is presented. The formulation is based on a previously developed isotropic creep model, assuming rotated Modified Cam Clay ellipses as contours of volumetric creep strain rates. A rotational hardening law is adopted to account for changes in anisotropy due to viscous strains. Although this will introduce some new soil parameters, they do not need calibration as they can be expressed as functions of basic soil parameters through simple analytical expressions. To start with, the one-dimensional response of the model is discussed, making it possible to explore how the model is capable of capturing key features of viscous soft soil behaviour. Subsequently, the three-dimensional generalisation of the model is presented, followed by comparison with experimental data, showing good agreement in both triaxial undrained compression and extension. In the authors' opinion, the simple formulation of the model makes it attractive for use in engineering practice

    Meningeal carcinomatosis diagnosed during stroke evaluation in the emergency department

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    A 70-year-old female presented to the emergency department with a 3-day history of intermittent dysphasia and right facial droop. Computed tomography (CT) and magnetic resonance imaging (MRI) were obtained, and the patient was found to have meningeal carcinomatosis, also known as leptomeningeal metastases. Meningeal carcinomatosis is a rare metastatic complication of some solid tumors and hematopoietic neoplasms, and has a median survival rate of 2.4 months. The role of the emergency physician is to appropriately diagnose this condition, treat emergent side effects, provide symptomatic relief, and ensure multi-disciplinary management

    Micromechanical analysis of kinematic hardening in natural clay

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    This paper presents a micromechanical analysis of the macroscopic behaviour of natural clay. A microstructural stress-strain model for clayey material has been developed which considers clay as a collection of clusters. The deformation of a representative volume of the material is generated by mobilizing and compressing all the clusters along their contact planes. Numerical simulations of multistage drained triaxial stress paths on Otaniemi clay have been performed and compared the numerical results to the experimental ones in order to validate the modelling approach. Then, the numerical results obtained at the microscopic level were analysed in order to explain the induced anisotropy observed in the clay behaviour at the macroscopic level. The evolution of the state variables at each contact plane during loading can explain the changes in shape and position in the stress space of the yield surface at the macroscopic level, as well as the rotation of the axes of anisotropy of the material

    Forty years studying British politics : the decline of Anglo-America

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    The still present belief some 40 years ago that British politics was both exceptional and superior has been replaced by more theoretically sophisticated analyses based on a wider and more rigorously deployed range of research techniques, although historical analysis appropriately remains important. The American influence on the study of British politics has declined, but the European Union dimension has not been fully integrated. The study of interest groups has been in some respects a fading paradigm, but important questions related to democratic health have still to be addressed. Public administration has been supplanted by public policy, but economic policy remains under-studied. A key challenge for the future is the study of the management of expectations

    Assessing the role of CAP for more sustainable and healthier food systems in Europe:A literature review

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    Today, the European food system is characterized by unhealthy dietary trends, environmentally unsustainable production, and a dependency on an ageing farming population. The ongoing reform of the Common Agricultural Policy (CAP) represents an opportunity to redress these issues. This literature review highlights trends in how academic and grey literature have received CAP attempts in addressing the (i) environmental issues, (ii) nutritional outcomes, and (iii) rural livelihoods. Additionally, future policy and research directions relating to the CAP have been identified from the selected literature. The reviewed literature varies in approach and perspective. In particular, since the environment and rural development are already part of the CAP, the reviewed studies analyze and propose improvements to existing mechanisms. While for nutrition, the reviewed studies assessed possible policy strategies for integrating this sphere within the CAP, highlighting both the complexity of this task as well as its potential benefits. Despite these differences, a clear commonality emerged from the policy recommendations: the CAP should promote the European Union (EU) policy integration and multi-disciplinary and participatory research as key strategies to meet food system sustainability targets.</p

    European tourism policy: Its evolution and structure

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    © 2015 Elsevier Ltd. This article reviews the procedural complexity of tourism policy-making by the European Commission leading up to the 2010 Communication. Initially, the European Commission had to present interventions affecting tourism as a community action or measure; intended to assist in the implementation of the Internal Market. Later, integration of the sustainable development principle into European Treaties established a framework for governance and a foundation for tourism policy, and the Lisbon Treaty in 2007 established a European policy that explicitly related to tourism, albeit a complementary competence in character. This article highlights a lack of leadership from the Member States throughout the process and contrasts this with the self-serving, driving force of the Commission in making tourism policy that focuses primarily on promotional actions. Consequently, the Commission has not created a robust, dynamic, flexible European model for tourism, designed in a way to best serve the needs of the Member States

    Evaluation of Readmission Ink as a Marker for Dispersal Studies with the Oriental Fruit Fly, Bactrocera dorsalis

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    In this text we present a new marking dye, readmission ink, Blak-Ray, for the purpose of insect movement studies. The dye was tested in a controlled experiment with Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) in anticipation of a long distance movement study planned for the following year with the same species. 700 individuals of both sexes were marked with the dye and placed in holding containers. Both the percentage of mortality and the ease of dye detection were monitored throughout a five-week period. Results showed minimal fly mortality and exceptional ease of dye detection

    The Mini‐Organo: A rapid high‐throughput 3D coculture organotypic assay for oncology screening and drug development

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    Background: The use of in vitro cell cultures is a powerful tool for obtaining key insights into the behaviour and response of cells to interventions in normal and disease situations. Unlike in vivo settings, in vitro experiments allow a fine-tuned control of a range of microenvironmental elements independently within an isolated setting. The recent expansion in the use of three-dimensional (3D) in vitro assays has created a number of representative tools to study cell behaviour in a more physiologically 3D relevant microenvironment. Complex 3D in vitro models that can recapitulate human tissue biology are essential for understanding the pathophysiology of disease. Aim: The development of the 3D coculture collagen contraction and invasion assay, the "organotypic assay," has been widely adopted as a powerful approach to bridge the gap between standard two-dimensional tissue culture and in vivo mouse models. In the cancer setting, these assays can then be used to dissect how stromal cells, such as cancer-associated fibroblasts (CAFs), drive extracellular matrix (ECM) remodelling to alter cancer cell behaviour and response to intervention. However, to date, many of the published organotypic protocols are low-throughput, time-consuming (up to several weeks), and work-intensive with often limited scalability. Our aim was to develop a fast, high-throughput, scalable 3D organotypic assay for use in oncology screening and drug development. Methods and results Here, we describe a modified 96-well organotypic assay, the "Mini-Organo," which can be easily completed within 5 days. We demonstrate its application in a wide range of mouse and human cancer biology approaches including evaluation of stromal cell 3D ECM remodelling, 3D cancer cell invasion, and the assessment of efficacy of potential anticancer therapeutic targets. Furthermore, the organotypic assay described is highly amenable to customisation using different cell types under diverse experimental conditions. Conclusions: The Mini-Organo high-throughput 3D organotypic assay allows the rapid screening of potential cancer therapeutics in human and mouse models in a time-efficient manner

    Genome-wide signatures of convergent evolution in echolocating mammals

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    Evolution is typically thought to proceed through divergence of genes, proteins, and ultimately phenotypes(1-3). However, similar traits might also evolve convergently in unrelated taxa due to similar selection pressures(4,5). Adaptive phenotypic convergence is widespread in nature, and recent results from a handful of genes have suggested that this phenomenon is powerful enough to also drive recurrent evolution at the sequence level(6-9). Where homoplasious substitutions do occur these have long been considered the result of neutral processes. However, recent studies have demonstrated that adaptive convergent sequence evolution can be detected in vertebrates using statistical methods that model parallel evolution(9,10) although the extent to which sequence convergence between genera occurs across genomes is unknown. Here we analyse genomic sequence data in mammals that have independently evolved echolocation and show for the first time that convergence is not a rare process restricted to a handful of loci but is instead widespread, continuously distributed and commonly driven by natural selection acting on a small number of sites per locus. Systematic analyses of convergent sequence evolution in 805,053 amino acids within 2,326 orthologous coding gene sequences compared across 22 mammals (including four new bat genomes) revealed signatures consistent with convergence in nearly 200 loci. Strong and significant support for convergence among bats and the dolphin was seen in numerous genes linked to hearing or deafness, consistent with an involvement in echolocation. Surprisingly we also found convergence in many genes linked to vision: the convergent signal of many sensory genes was robustly correlated with the strength of natural selection. This first attempt to detect genome-wide convergent sequence evolution across divergent taxa reveals the phenomenon to be much more pervasive than previously recognised

    Overview of a formal scoping review on health system report cards

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    Background: There is an extensive body of literature on health system quality reporting that has yet to be characterized. Scoping is a novel methodology for systematically assessing the breadth of a body of literature in a particular research area. Our objectives were to showcase the scoping review methodology in the review of health system quality reporting, and to report on the extent of the literature in this area.Methods: A scoping review was performed based on the York methodology outlined by Arksey and O'Malley from the University of York, United Kingdom. We searched 14 peer reviewed and grey literature databases limiting the search to English language and non-English language articles with English abstracts published between 1980 and June 2006 with an update to November 2008. We also searched specific websites, reference lists, and key journals for relevant material and solicited input from key stakeholders. Inclusion/exclusion criteria were applied to select relevant material and qualitative information was charted from the selected literature.Results: A total of 10,102 articles were identified from searching the literature databases, 821 were deemed relevant to our scoping review. An additional 401 were identified from updates, website searching, references lists, key journals, and stakeholder suggestions for a total of 1,222 included articles. These were categorized and catalogued according to the inclusion criteria, and further subcategories were identified through the charting process. Topic areas represented by this review included the effectiveness of health system report cards (n = 194 articles), methodological issues in their development (n = 815 articles), stakeholder views on report cards (n = 144 articles), and ethical considerations around their development (n = 69 articles).Conclusions: The scoping review methodology has permitted us to characterize and catalogue the extensive body of literature pertaining to health system report cards. The resulting literature repository that our review has created can be of use to researchers and health system stakeholders interested in the topic of health system quality measurement and reporting. © 2010 Brien et al; licensee BioMed Central Ltd
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