387 research outputs found

    MARTE based design approach for targeting Reconfigurable Architectures

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    International audienceThis paper demonstrates the use of a model driven design flow for Multiprocessor System on chips (MPSoCs) such as those dedicated to intensive signal processing applications. Due to the continuous exponential rise in SoC's design complexity, there is a critical need to find new seamless methodologies and tools to handle the SoC co-design aspects. This paper addresses this issue and proposes a novel SoC codesign methodology based on Model Driven Engineering (MDE) and the MARTE (Modeling and Analysis of Real-Time and Embedded Systems) standard proposed by OMG (Object Management Group), in order to raise the design abstraction levels. Extensions of this standard have enabled us to move from high level specifications to execution platforms such as reconfigurable FPGAs

    Quantifying circumpolar summer habitat for Antarctic krill and Ice krill, two key species of the Antarctic marine ecosystem

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    Antarctic krill (Euphausia superba) and Ice krill (Euphausia crystallorophias) are key species within Southern Ocean marine ecosystems. Given their importance in regional food webs, coupled with the uncertain impacts of climate change, the on-going recovery of krill-eating marine mammals, and the expanding commercial fishery for Antarctic krill, there is an increasing need to improve current estimates of their circumpolar habitat distribution. Here, we provide an estimate of the austral summer circumpolar habitat distribution of both species using an ensemble of habitat models and updated environmental covariates. Our models were able to resolve the segregated habitats of both species. We find that extensive potential habitat for Antarctic krill is mainly situated in the open ocean and concentrated in the Atlantic sector of the Southern Ocean, while Ice krill habitat was concentrated more evenly around the continent, largely over the continental shelf. Ice krill habitat was mainly predicted by surface oxygen concentration and water column temperature, while Antarctic krill was additionally characterized by mixed layer depth, distance to the continental shelf edge, and surface salinity. Our results further improve understanding about these key species, helping inform sustainable circumpolar management practices

    Did tool-use evolve with enhanced physical cognitive abilities?

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    The use and manufacture of tools have been considered to be cognitively demanding and thus a possible driving factor in the evolution of intelligence. In this study, we tested the hypothesis that enhanced physical cognitive abilities evolved in conjunction with the use of tools, by comparing the performance of naturally tool-using and non-tool-using species in a suite of physical and general learning tasks. We predicted that the habitually tool-using species, New Caledonian crows and Galápagos woodpecker finches, should outperform their non-tool-using relatives, the small tree finches and the carrion crows in a physical problem but not in general learning tasks. We only found a divergence in the predicted direction for corvids. That only one of our comparisons supports the predictions under this hypothesis might be attributable to different complexities of tool-use in the two tool-using species. A critical evaluation is offered of the conceptual and methodological problems inherent in comparative studies on tool-related cognitive abilities

    Accelerated Projected Gradient Method for Linear Inverse Problems with Sparsity Constraints

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    Regularization of ill-posed linear inverse problems via 1\ell_1 penalization has been proposed for cases where the solution is known to be (almost) sparse. One way to obtain the minimizer of such an 1\ell_1 penalized functional is via an iterative soft-thresholding algorithm. We propose an alternative implementation to 1\ell_1-constraints, using a gradient method, with projection on 1\ell_1-balls. The corresponding algorithm uses again iterative soft-thresholding, now with a variable thresholding parameter. We also propose accelerated versions of this iterative method, using ingredients of the (linear) steepest descent method. We prove convergence in norm for one of these projected gradient methods, without and with acceleration.Comment: 24 pages, 5 figures. v2: added reference, some amendments, 27 page

    A critical analysis of the hepatotoxicity cases described in the literature related to Herbalife (r) products

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    Abstract The aim of this study was to assess the hepatotoxicity cases described in the literature, attributed to the consumption of Herbalife(r) products, and to determine whether a causal relationship exists between the reported cases of liver injury and the use of these products. A literature search was performed on the PubMed, LILACS and PAHO databases. Seven publications reporting a total of 53 cases of hepatotoxicity linked to the use of Herbalife(r) products were retrieved. All of the studies lacked sufficient information to some degree, whether related to patients' history, concomitant use of medication and/or other compounds (including alcohol), observations on interrupted use (dechallenge), results found with markers, viral serology and autoantibodies or observations concerning re-exposure to the products. In addition to these items, the lack of clear information on the type of products evaluated and their respective composition is an important factor to be considered. Furthermore, data quality was also questionable due to the presence of confounding factors, absence of proper exclusion of alternative explanations, and the use of questionable methods for attributing causality. Hence, an association between hepatotoxicity and consumption of these products cannot be proven based on the data collected and rigorous scientific analysis

    Risk factors for respiratory work disability in a cohort of pulp mill workers exposed to irritant gases

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    <p>Abstract</p> <p>Background</p> <p>The association between chronic respiratory diseases and work disability has been demonstrated a number of times over the past 20 years, but still little is known about work disability in occupational cohorts of workers exposed to respiratory irritants. This study investigated job or task changes due to respiratory problems as an indicator of work disability in pulp mill workers occupationally exposed to irritants.</p> <p>Methods</p> <p>Data about respiratory symptoms and disease diagnoses, socio-demographic variables, occupational exposures, gassing episodes, and reported work changes due to respiratory problems were collected using a questionnaire answered by 3226 pulp mill workers. Information about work history and departments was obtained from personnel files. Incidence and hazard ratios for respiratory work disability were calculated with 95% confidence intervals (CI).</p> <p>Results</p> <p>The incidence of respiratory work disability among these pulp mill workers was 1.6/1000 person-years. The hazard ratios for respiratory work disability were increased for workers reporting gassings (HR 5.3, 95% CI 2.7-10.5) and for those reporting physician-diagnosed asthma, chronic bronchitis, and chronic rhinitis, when analyzed in the same model.</p> <p>Conclusions</p> <p>This cohort study of pulp mill workers found that irritant peak exposure during gassing episodes was a strong predictor of changing work due to respiratory problems, even after adjustment for asthma, chronic bronchitis, and chronic rhinitis.</p

    Uneven and combined development and unequal exchange: the second wind of neoliberal ‘free trade’?

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    With capitalist social relations emerging in a prior system of absolutist states in Europe, the outward expansion of capitalism through conditions of uneven and combined development became dependent on the existence of multiple political entities. States in turn are brought into relations of unequal exchange within the global economy. This article analyses the way in which current neoliberal ‘free trade’ policies are related to these fundamental capitalist dynamics, deepening further processes of uneven and combined development as well as unequal exchange
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