756 research outputs found

    Exploring the drivers of malnutrition in West Africa from health and social science perspectives : a comparative methodological review

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    West Africa has a high burden of malnutrition and the drivers are often complex, highly context-specific, and cut across individual, social, political and environmental domains. Public health research most often considers immediate individual health and diet drivers, at the expense of wider considerations that may fall outside of a health agenda. The objective of this systematic mapping review is to map the broad drivers of malnutrition in West Africa, from public health and social science perspectives, and to evaluate the additional value of an interdisciplinary approach. Evidence was gathered from one public health (MEDLINE) and one social science (International Bibliography of Social Science) database using a detailed search syntax tailored to each disciplinary configuration. Literature was screened against pre-determined eligibility criteria and extracted from abstracts. Studies published in English or French between January 2010 and April 2018 were considered for inclusion. Driver categories (immediate, underlying and basic drivers) were coded against the UNICEF conceptual framework of malnutrition. A total of 358 studies were included; 237 were retrieved from the public health database and 124 from the social science database, 3 studies were included in both. The public health and social science literature document different drivers, with MEDLINE most often reporting immediate drivers of malnutrition and the International Bibliography of Social Science database reporting underlying and basic drivers. The combined literature offers more balanced representation across categories. An interdisciplinary approach proved successful in achieving complementarity in search results while upholding rigorous methods. We recommend that interdisciplinary approaches are utilised to bridge recognised gaps between defined disciplines

    Chondroblastoma: An Unusual Cause Of Shoulder Pain In Adolescence

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    Chondroblastoma is a rare benign bone tumor, most often localized in the epiphysis of long bones. We report a case of atraumatic shoulder pain in a 17-year old soccer player. This chondroblastoma case demonstrates the difficult differentiation of chondroblastoma from giant cell tumor and clear cell chondrosarcoma and highlights possible pitfalls and clinical importance

    Reservoir Computing Approach to Robust Computation using Unreliable Nanoscale Networks

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    As we approach the physical limits of CMOS technology, advances in materials science and nanotechnology are making available a variety of unconventional computing substrates that can potentially replace top-down-designed silicon-based computing devices. Inherent stochasticity in the fabrication process and nanometer scale of these substrates inevitably lead to design variations, defects, faults, and noise in the resulting devices. A key challenge is how to harness such devices to perform robust computation. We propose reservoir computing as a solution. In reservoir computing, computation takes place by translating the dynamics of an excited medium, called a reservoir, into a desired output. This approach eliminates the need for external control and redundancy, and the programming is done using a closed-form regression problem on the output, which also allows concurrent programming using a single device. Using a theoretical model, we show that both regular and irregular reservoirs are intrinsically robust to structural noise as they perform computation

    Reorganization of the nuclear lamina and cytoskeleton in adipogenesis

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    A thorough understanding of fat cell biology is necessary to counter the epidemic of obesity. Although molecular pathways governing adipogenesis are well delineated, the structure of the nuclear lamina and nuclear-cytoskeleton junction in this process are not. The identification of the ‘linker of nucleus and cytoskeleton’ (LINC) complex made us consider a role for the nuclear lamina in adipose conversion. We herein focused on the structure of the nuclear lamina and its coupling to the vimentin network, which forms a cage-like structure surrounding individual lipid droplets in mature adipocytes. Analysis of a mouse and human model system for fat cell differentiation showed fragmentation of the nuclear lamina and subsequent loss of lamins A, C, B1 and emerin at the nuclear rim, which coincides with reorganization of the nesprin-3/plectin/vimentin complex into a network lining lipid droplets. Upon 18 days of fat cell differentiation, the fraction of adipocytes expressing lamins A, C and B1 at the nuclear rim increased, though overall lamin A/C protein levels were low. Lamin B2 remained at the nuclear rim throughout fat cell differentiation. Light and electron microscopy of a subcutaneous adipose tissue specimen showed striking indentations of the nucleus by lipid droplets, suggestive for an increased plasticity of the nucleus due to profound reorganization of the cellular infrastructure. This dynamic reorganization of the nuclear lamina in adipogenesis is an important finding that may open up new venues for research in and treatment of obesity and nuclear lamina-associated lipodystrophy

    Kinetics of extracellular ATP in mastoparan 7-activated human erythrocytes

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    Background: The peptide mastoparan 7 (MST7) stimulated ATP release in human erythrocytes. We explored intraand extracellular processes governing the time-dependent accumulation of extracellular ATP (i.e., ATPe kinetics). Methods: Human erythrocytes were treated with MST7 in the presence or absence of two blockers of pannexin 1. ATPe concentration was monitored by luciferin–luciferase based real-time luminometry. Results: Exposure of human erythrocytes to MST7 led to an acute increase in [ATPe], followed by a slower increase phase. ATPe kinetics reflected a strong activation of ATP efflux and a low rate of ATPe hydrolysis by ectoATPase activity. Enhancement of [ATPe] by MST7 required adhesion of erythrocytes to poly-D-lysin-coated coverslips, and correlated with a 31% increase of cAMP and 10% cell swelling. However, when MST7 was dissolved in a hyperosmotic medium to block cell swelling, ATPe accumulation was inhibited by 49%. Erythrocytes pre-exposure to 10 μM of either carbenoxolone or probenecid, two blockers of pannexin 1, exhibited a partial reduction of ATP efflux. Erythrocytes from pannexin 1 knockout mice exhibited similar ATPe kinetics as those of wild type mice erythrocytes exposed to pannexin 1 blockers. Conclusions: MST7 induced release of ATP required either cell adhesion or strong activation of cAMP synthesis. Part of this release required cell swelling. Kinetic analysis and a data driven model suggested that ATP efflux is mediated by two ATP conduits displaying different kinetics, with one conduit being fully blocked by pannexin 1 blockers. General significance: Kinetic analysis of extracellular ATP accumulation from human erythrocytes and potential effects on microcirculation.Fil: Leal Denis, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; ArgentinaFil: Incicco, Juan Jeremías. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; ArgentinaFil: Espelt, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; ArgentinaFil: Verstraeten, Sandra Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; ArgentinaFil: Pignataro, Omar Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Lazarowski, Eduardo R.. University of North Carolina at Chapel Hill. Cystic Fibrosis/Pulmonary Research and Treatment Center; Estados UnidosFil: Schwarzbaum, Pablo Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; Argentin

    Interoperability for the design and construction industry through semantic web technology

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    The domain of architecture, engineering and construction (AEC) has experienced significant improvements with the advent of building information modelling (BIM) applications, which allow AEC specialists to model all information concerning a building design into one three-dimensional building model. Much of these improvements are however generated by the mere availability of such an environment, whereas many more improvements were expected by achieving an appropriate interoperability of information. We are investigating why such an interoperability is not reached fully and consider the semantic web as an alternative approach to reach the targeted interoperability. In this paper, an AEC description framework based on semantic web technology is presented and compared to the BIM approach, after which we indicate how it might solve the issue of interoperability more appropriately. Our evaluation of this investigation indicates the semantic web approach as a valid alternative approach, although considerably more research is needed to show it capable of providing the targeted interoperability of information in the AEC domain

    Recognizing recurrent neural networks (rRNN): Bayesian inference for recurrent neural networks

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    Recurrent neural networks (RNNs) are widely used in computational neuroscience and machine learning applications. In an RNN, each neuron computes its output as a nonlinear function of its integrated input. While the importance of RNNs, especially as models of brain processing, is undisputed, it is also widely acknowledged that the computations in standard RNN models may be an over-simplification of what real neuronal networks compute. Here, we suggest that the RNN approach may be made both neurobiologically more plausible and computationally more powerful by its fusion with Bayesian inference techniques for nonlinear dynamical systems. In this scheme, we use an RNN as a generative model of dynamic input caused by the environment, e.g. of speech or kinematics. Given this generative RNN model, we derive Bayesian update equations that can decode its output. Critically, these updates define a 'recognizing RNN' (rRNN), in which neurons compute and exchange prediction and prediction error messages. The rRNN has several desirable features that a conventional RNN does not have, for example, fast decoding of dynamic stimuli and robustness to initial conditions and noise. Furthermore, it implements a predictive coding scheme for dynamic inputs. We suggest that the Bayesian inversion of recurrent neural networks may be useful both as a model of brain function and as a machine learning tool. We illustrate the use of the rRNN by an application to the online decoding (i.e. recognition) of human kinematics

    Robotic ubiquitous cognitive ecology for smart homes

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    Robotic ecologies are networks of heterogeneous robotic devices pervasively embedded in everyday environments, where they cooperate to perform complex tasks. While their potential makes them increasingly popular, one fundamental problem is how to make them both autonomous and adaptive, so as to reduce the amount of preparation, pre-programming and human supervision that they require in real world applications. The project RUBICON develops learning solutions which yield cheaper, adaptive and efficient coordination of robotic ecologies. The approach we pursue builds upon a unique combination of methods from cognitive robotics, machine learning, planning and agent- based control, and wireless sensor networks. This paper illustrates the innovations advanced by RUBICON in each of these fronts before describing how the resulting techniques have been integrated and applied to a smart home scenario. The resulting system is able to provide useful services and pro-actively assist the users in their activities. RUBICON learns through an incremental and progressive approach driven by the feed- back received from its own activities and from the user, while also self-organizing the manner in which it uses available sensors, actuators and other functional components in the process. This paper summarises some of the lessons learned by adopting such an approach and outlines promising directions for future work
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