127 research outputs found
Vertical Elasticity on Marathon and Chronos Mesos frameworks
[EN] Marathon and Chronos are two popular Mesos frameworks that are widely used for deploying fault-tolerant services and periodic batch jobs. Marathon and Chronos provide by design mechanisms for horizontal elasticity, scaling up and down the number of job and service instances. Horizontal elasticity is appropriate when the problems that are solved are inherently parallel. However, when the problem cannot benefit from an increase of the amount of resources, vertical elasticity must be considered. This work implements on top of Marathon and Chronos Mesos frameworks, a mechanism to vary the resources associated to an executor dynamically, according to its progress and considering specific Quality of Service (QoS). The mechanism developed provides a wrapper executable and a service that takes the decision of increasing or decreasing the resources allocated to different Chronos iterations or a long-living Marathon application. The mechanism makes use of checkpointing techniques to preserve the execution of Marathon applications and leverages OpenStack Monasca for the monitoring. \footnote{The work in this article has been funded by projects BIGCLOE and EUBra-BIGSEA, BIGLOE is funded by the Spanish ``Ministerio de Econom\'ia, Industria y Competitividad" with reference number TIN2016-79951-R and EUBra-BIGSEA is funded jointly by the European Commission under the Cooperation Programme, Horizon 2020 grant agreement No 690116 and the Brazilian Ministério de Ciência, Tecnologia e Inovação (MCTI).The work in this article has been funded by projects BIGCLOE and EUBra BIGSEA, BIGLOE is funded by the Spanish "Ministerio de Economia, Industria y Competitividad" with reference number TIN2016-79951-R and EUBra-BIGSEA is funded jointly by the European Commission under the Cooperation Programme, Horizon 2020 grant agreement No 690116 and the Brazilian Ministerio de Ciencia, Tecnologia e Inovacao (MCTI).López-Huguet, S.; Natanael, I.; Brito, A.; Blanquer Espert, I. (2019). Vertical Elasticity on Marathon and Chronos Mesos frameworks. Journal of Parallel and Distributed Computing. 133:179-192. https://doi.org/10.1016/j.jpdc.2019.01.002S17919213
Forest resilience to global warming is strongly modulated by local-scale topographic, microclimatic and biotic conditions
Resilience of endangered rear edge populations of cold-adapted forests in the Mediterranean basin is increasingly altered by extreme heatwave and drought pressures. It remains unknown, however, whether microclimatic variation in these isolated forests could ultimately result in large intra-population variability in the demographic responses, allowing the coexistence of contrasting declining and resilient trends across small topographic gradients. Multiple key drivers promoting spatial variability in the resilience of rear edge forests remain largely unassessed, including amplified and buffered thermal exposure induced by heatwaves along topographic gradients, and increased herbivory pressure on tree saplings in defaunated areas lacking efficient apex predators. Here we analysed whether indicators of forest resilience to global warming are strongly modulated by local-scale topographic, microclimatic and biotic conditions. We studied a protected rear edge forest of sessile oak Quercus petraea, applying a suite of 20 indicators of resilience of tree secondary growth, including multidecadal and short-term indices. We also analysed sapling recruitment success, recruit/adult ratios and sapling thermal exposure across topographic gradients. We found large within population variation in secondary growth resilience, in recruitment success and in thermal exposure of tree saplings to heatwaves, and this variability was spatially structured along small-scale topographical gradients. Multidecadal resilience indices and curves provide useful descriptors of forest vulnerability to climate warming, complementing assessments based in the analysis of short-term resilience indicators. Species-specific associations of trees with microclimatic variability are reported. Biotic factors are key in determining long-term resilience in climatically stressed rear edge forests, with strong limitation of sapling recruitment by increased roe deer and wild boar herbivory. Our results also support non-stationary effects of climate determining forest growth responses and resilience, showing increased negative effects of warming and drought over the last decades in declining stands. Synthesis. Our findings do not support scenarios predicting spatially homogeneous distributional shifts and limited resilience in rear edge populations, and are more supportive of scenarios including spatially heterogeneous responses, characterised with contrasting intra-population trends of forest resilience. We conclude that forest resilience responses to climate warming are strongly modulated by local-scale microclimatic, topographic and biotic factors. Accurate predictions of forest responses to changes in climate would therefore largely benefit from the integration of local-scale abiotic and biotic factors
Estudio del Síndrome de apnea-hipopnea del sueño y la resistencia a la insulina
El nostre objectiu fou analitzar la prevalença de la resistència a la insulina (RI) en una cohort de pacients amb síndrome d'apnea-hipopnea de la son (SAHS) sota la hipòtesi que el SAHS és un factor de risc independent per al desenvolupament de RI. Realitzarem un estudi prospectiu transversal incloent-hi pacients consecutius diagnosticats de SAHS. Estudiarem les diferències entre pacients SAHS amb i sense RI. Incloem 103 pacients (73,8% homes). El 46,7% (n=42) tenien RI, i aquest grup va tenir major IMC i paràmetres més greus d'hipòxia intermitent nocturna. Els factors de risc independents per a la RI van ser l'IMC i l'ODINuestro objetivo fue analizar la prevalencia de la resistencia a la insulina (RI) en una cohorte de pacientes con síndrome de apnea-hipopnea del sueño (SAHS) bajo la hipótesis de que el SAHS es un factor de riesgo independiente para el desarrollo de RI. Realizamos un estudio prospectivo transversal incluyendo pacientes consecutivos diagnosticados de SAHS. Estudiamos las diferencias entre pacientes SAHS con y sin RI. Incluímos 103 pacientes (73,8% hombres). El 46,7% (n=42) tenían RI, y éste grupo tuvo mayor IMC y parámetros de mayor gravedad de hipoxia intermitente nocturna. Los factores de riesgo independientes para la RI fueron el IMC y el ODI
High-resolution tSZ cartography of clusters of galaxies with NIKA at the IRAM 30-m telescope
The thermal Sunyaev-Zeldovich effect (tSZ) is a powerful probe to study
clusters of galaxies and is complementary with respect to X-ray, lensing or
optical observations. Previous arcmin resolution tSZ observations ({\it e.g.}
SPT, ACT and Planck) only enabled detailed studies of the intra-cluster medium
morphology for low redshift clusters (). Thus, the development of
precision cosmology with clusters requires high angular resolution observations
to extend the understanding of galaxy cluster towards high redshift. NIKA2 is a
wide-field (6.5 arcmin field of view) dual-band camera, operated at and containing KID (Kinetic Inductance Detectors), designed to
observe the millimeter sky at 150 and 260 GHz, with an angular resolution of 18
and 12 arcsec respectively. The NIKA2 camera has been installed on the IRAM
30-m telescope (Pico Veleta, Spain) in September 2015. The NIKA2 tSZ
observation program will allow us to observe a large sample of clusters (50) at
redshift ranging between 0.5 and 1. As a pathfinder for NIKA2, several clusters
of galaxies have been observed at the IRAM 30-m telescope with the NIKA
prototype to cover the various configurations and observation conditions
expected for NIKA2.Comment: Proceedings of the 28th Texas Symposium on Relativistic Astrophysics,
Geneva, Switzerland, December 13-18, 201
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