298 research outputs found

    Protéger en partageant : stratégies de croissance intelligente applicables en milieu rural

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    Cette recherche amorcée par l’étude du cas de Sutton avait pour objectifs de décrire les mécanismes de Smart Growth permettant de concilier la protection du territoire avec l’accessibilité à l’habitation avant d’analyser leur portée, leurs limites et leur potentielle applicabilité au milieu rural. Au premier degré, l’analyse a permis de mettre en évidence la grande variété des mécanismes existants et la rareté de stratégies d’ensemble structurant leur application. Au second degré, le niveau d’intégration des outils de contrôle spatial et économique du développement, la marge de manoeuvre légale concédée aux municipalités par les paliers supérieurs de gouvernement, les valeurs sociales et la capacité d’organisation des collectivités ont été identifiés comme les principaux facteurs influant sur la portée et les limites potentielles de ces mécanismes. Le poids du tourisme et de la villégiature dans l’économie des collectivités rurales sous pression a été ciblé comme une contrainte majeure à leur mise en oeuvre dans ce type de contexte. La dépendance des municipalités aux revenus de taxes foncières et une logique économique basée sur une croissance soutenue de la richesse - foncière, entre autres - ont par ailleurs été identifiées comme des facteurs limitant fortement la portée potentielle des stratégies visant à améliorer l’abordabilité de l’habitation. En conclusion, les potentiels d’application au contexte de Sutton sont évoqués sous la forme d’une recherche-action visant à la mise en oeuvre des mécanismes les plus prometteurs

    A User Friendly Phase Detection Methodology for HPC Systems' Analysis

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    International audienceA wide array of today's high performance computing (HPC) applications exhibits recurring behaviours or execution phases throughout their run-time. Accurate detection of program phases allows reconfiguring the system for a better power/performance trade off; and can reduce the simulation time of programs by identifying regions of code whose performance is critical to the entire program. Program phases are also reflected in different behaviours the system goes through or system phases, which can be used as an alternative means of program phase detection for users lacking expertise. In this paper, we present an execution vector based (EV-based) phase detection, which is an on-line methodology for detecting phases in the behaviour of a HPC system and determining execution points that correspond to these phases. We also present a methodology for defining a small set of EVs representative of the system's behaviour over a fixed period of time and show that EV-based phase detection identifies recurring phases. Our methodology is illustrated with benchmarks and a real life application

    A Runtime Framework for Energy Efficient HPC Systems Without a Priori Knowledge of Applications

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    International audienceThe rising computing demands of scientific endeavours often require the creation and management of High Performance Computing (HPC) systems for running experiments and processing vast amounts of data. These HPC systems generally operate at peak performance, consuming a large quantity of electricity, even though their workload varies over time. Understanding the behavioural patterns i.e., phases) of HPC systems during their use is key to adjust performance to resource demand and hence improve the energy efficiency. In this paper, we describe (i) a method to detect phases of an HPC system based on its workload, and (ii) a partial phase recognition technique that works cooperatively with on-the-fly dynamic management. We implement a prototype that guides the use of energy saving capabilities to demonstrate the benefits of our approach. Experimental results reveal the effectiveness of the phase detection method under real-life workload and benchmarks. A comparison with baseline unmanaged execution shows that the partial phase recognition technique saves up to 15% of energy with less than 1% performance degradation

    Exploiting Performance Counters to Predict and Improve Energy Performance of HPC Systems

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    International audienceHardware monitoring through performance counters is available on almost all modern processors. Although these counters are originally designed for performance tuning, they have also been used for evaluating power consumption. We propose two approaches for modelling and understanding the behaviour of high performance computing (HPC) systems relying on hardware monitoring counters. We evaluate the effectiveness of our system modelling approach considering both optimising the energy usage of HPC systems and predicting HPC applications' energy consumption as target objectives. Although hardware monitoring counters are used for modelling the system, other methods -- including partial phase recognition and cross platform energy prediction -- are used for energy optimisation and prediction. Experimental results for energy prediction demonstrate that we can accurately predict the peak energy consumption of an application on a target platform; whereas, results for energy optimisation indicate that with no a priori knowledge of workloads sharing the platform we can save up to 24\% of the overall HPC system's energy consumption under benchmarks and real-life workloads

    Evaluation of the efficacy and safety of artemether-lumefantrine in the treatment of acute uncomplicated Plasmodium falciparum malaria in Nigerian infants and children

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    <p>Abstract</p> <p>Background</p> <p>The six-dose regimen of artemether-lumefantrine (AL) is now considered the gold standard for the treatment of uncomplicated <it>Plasmodium falciparum </it>malaria. There are few reports evaluating co-artemether in very young Nigerian infants and children. Results of the evaluation of the six-dose regimen in very young infants and children in Nigeria are presented in this report.</p> <p>Methods</p> <p>As part of a larger African study, this open label, non-comparative trial, assessed the efficacy and safety of six-dose regimen of AL tablets in 103 Nigerian infants and children weighing between five and 25 kg suffering from acute uncomplicated malaria. Treatment was administered under supervision over three days with children as in-patients. 12-lead ECG tracings were taken pre-treatment and at day 3.</p> <p>Results</p> <p>Ninety-three infants and children completed the study as stipulated by the protocol. Mean fever and parasite clearance times for the intent to treat population (ITT) were 24.9 h ± (1.28) and 26 h ± (4.14) and the corresponding figures for the per-protocol population (PP) were 19.24 h ± 13.9 and 25.62 h ± 11.25 respectively. Day 14 cure rates for the ITT and PP were 95.1% and 100% respectively while day 28 cure rates were 91.3% and 95.7% respectively. The overall PCR corrected day 28 cure rate was 95.1% for the ITT. The six-dose regimen of AL was well tolerated with no drug-related serious adverse events. Although six patients recorded a QTc prolongation of > 60 ms on D3 over D0 recording, no patient recorded a QTc interval > 500 ms.</p> <p>Conclusion</p> <p>The six-dose regimen of AL tablets is safe and effective for the treatment of acute uncomplicated malaria in Nigerian infants and children weighing between five and 25 kg.</p> <p>Trial registration</p> <p>NCT00709969</p

    Recurrent dust formation by WR 48a on a 30-year timescale

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    We present infrared photometry of the WC8 Wolf-Rayet system WR 48a observed with telescopes at ESO, the SAAO and the AAT between 1982 and 2011 which show a slow decline in dust emission from the previously reported outburst in 1978--79 until about 1997, when significant dust emission was still evident. This was followed by a slow rise, accelerating to reach and overtake the first (1978) photometry, demonstrating that the outburst observed in 1978--79 was not an isolated event, but that they recur at intervals of 32+ years. This suggests that WR 48a is a long-period dust maker and colliding-wind binary (CWB). The locus of WR 48a in the (H-L), K colour-magnitude diagram implies that the rate of dust formation fell between 1979 and about 1997 and then increased steadily until 2011. Superimposed on the long-term variation are secondary (`mini') eruptions in (at least) 1990, 1994, 1997, 1999 and 2004, characteristic of relatively brief episodes of additional dust formation. Spectra show evidence for an Oe or Be companion to the WC8 star, supporting the suggestion that WR 48a is a binary system and indicating a system luminosity consistent with the association of WR 48a and the young star clusters Danks 1 and Danks 2. The range of dust formation suggests that these stars are in an elliptical orbit having e ~ 0.6. The size of the orbit implied by the minimum period, together with the WC wind velocity and likely mass-loss rate, implies that the post-shock WC wind is adiabatic throughout the orbit -- at odds with the observed dust formation. A similar conflict is observed in the `pinwheel' dust-maker WR 112.Comment: 15 pages, 8 figures, accepted for publication in MNRA

    Arquitetura residencial verticalizada em São Paulo nas décadas de 1930 e 1940

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    O presente trabalho aborda o tema, ainda pouco estudado, da arquitetura residencial verticalizada em São Paulo, nas décadas de 1930 e 1940. A partir de alguns estudos de caso representativos, são apresentadas observações relativas a aspectos como: as estratégias de disseminação da nova forma de morar; as opções estéticas disponíveis; a definição dos programas das unidades e as soluções de planta desenvolvidas. Espera-se evidenciar a riqueza e complexidade do assunto, que se configura não apenas como importante tema da história da arquitetura paulistana, mas, principalmente, como significativo patrimônio cultural da cidade, a ser conhecido e protegido.The present work addresses the topic, as yet scarcely studied, of high-rise residential architecture in Sao Paulo during the 1940s and 50s. Supported by some representative case studies, observations were drawn on the following aspects: the strategies used to propagate this new dwelling form, the available aesthetical options for these buildings, the definition of these units' purposes and uses and the development of ground plan architectural solutions. This article aims to render evident the great value and complexity of its subject matter, which is not only extremely important as a theme of Sao Paulo's architectural history, but also, and foremostly, as a significant cultural heritage of this city, which should be acknowledged and safeguarded

    Global Carbon Budget 2023

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    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land-use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based f CO2 products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. Additional lines of evidence on land and ocean sinks are provided by atmospheric inversions, atmospheric oxygen measurements, and Earth system models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and incomplete understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2022, EFOS increased by 0.9 % relative to 2021, with fossil emissions at 9.9 ± 0.5 Gt C yr−1 (10.2 ± 0.5 Gt C yr−1 when the cement carbonation sink is not included), and ELUC was 1.2 ± 0.7 Gt C yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 11.1 ± 0.8 Gt C yr−1 (40.7±3.2 Gt CO2 yr−1). Also, for 2022, GATM was 4.6±0.2 Gt C yr−1 (2.18±0.1 ppm yr−1; ppm denotes parts per million), SOCEAN was 2.8 ± 0.4 Gt C yr−1, and SLAND was 3.8 ± 0.8 Gt C yr−1, with a BIM of −0.1 Gt C yr−1 (i.e. total estimated sources marginally too low or sinks marginally too high). The global atmospheric CO2 concentration averaged over 2022 reached 417.1 ± 0.1 ppm. Preliminary data for 2023 suggest an increase in EFOS relative to 2022 of +1.1 % (0.0 % to 2.1 %) globally and atmospheric CO2 concentration reaching 419.3 ppm, 51 % above the pre-industrial level (around 278 ppm in 1750). Overall, the mean of and trend in the components of the global carbon budget are consistently estimated over the period 1959–2022, with a near-zero overall budget imbalance, although discrepancies of up to around 1 Gt C yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows the following: (1) a persistent large uncertainty in the estimate of land-use changes emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living-data update documents changes in methods and data sets applied to this most recent global carbon budget as well as evolving community understanding of the global carbon cycle. The data presented in this work are available at https://doi.org/10.18160/GCP-2023 (Friedlingstein et al., 2023)

    Témoignage 3. Travailler la campagne

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    Crédits photographiques : Gérald Domon La campagne de Sutton est si belle qu’elle donne souvent l’impression de vivre dans une carte postale grandeur nature. Mais ceux qui l’ont défrichée pour en tirer leur maigre pitance ne se doutaient certainement pas que leurs « terres de roches » allaient se métamorphoser, au début du XXIe siècle, en « vues à un million de dollars ». Il n’existe malheureusement pas d’équivalent français du terme « working landscape » qui décrit si bien, chez nos voisins ..
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