3,745 research outputs found

    Discours multilatéraliste, leadership réaliste : l'évolution de la conduite institutionnelle de sécurité des États-Unis sous Clinton

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    Cet article analyse le rôle et l'influence des institutions internationales de sécurité à travers l'étude du comportement des États-Unis envers la réforme du Conseil de sécurité des Nations Unies, la consolidation de la paix en Bosnie, et l'élargissement de I'OTAN. L'analyse des trois cas démontre que l'administration Clinton a graduellement diminué l'importance accordée aux institutions internationales dans le maintien de la sécurité internationale. Les États-Unis ont accentué leur leadership au sein des institutions afin de définir l'agenda de sécurité en fonction de leurs intérêts. La poursuite des objectifs américains a été davantage influencée par les débats au sein du gouvernement et les demandes des acteurs extérieurs que par les institutions internationales. Celles-ci ont généralement servi de complément aux pratiques souhaitées par les États-Unis et ne se sont pas substituées au rôle que la superpuissance s'attribuait en sécurité internationaleThis article assesses the role and influence of international security institutions through analysis of the United States' behavior towards the reform of the Security Council, peacebuilding in Bosnia, and NATO enlargement. The study demonstrates that the Clinton Administration gradually came to grant less importance to international institutions in ensuring the world's security. The United States intensified its leadership within the institutions in order to define the security agenda in terms of its interests. The pursuit of American interests was more influenced by debates within the government and demands from external actors than by international institutions. Institutions assisted the desired behavior of the US, and did not serve as a substitute for the role the superpower saw for it self in world politics

    Mixed Critical Automotive Embedded Applications on Multicores: A Safe Scheduling Approach for Dependability

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    International audienceMemory access durations on multicore architectures are highly variable, since concurrent accesses to memory by different cores induce time interferences. Consequently, critical software tasks may be delayed by noncritical ones, leading to deadline misses and possible catastrophic failures. We present an approach to tackle the implementation of mixed criticality workloads on multicore chips, focusing on task chains, i.e., sequences of tasks with end-to-end deadlines. Our main contribution is a Monitoring & Control System able to stop noncritical software execution in order to prevent memory interference and guarantee that critical tasks deadlines are met. This paper describes our approach, and the associated experimental framework to conduct experiments to analyze attainable real-time guarantees on a multicore platform

    Generating all Possible Palindromes from Ngram Corpora

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    International audienceWe address the problem of generating all possible palindromes from a corpus of Ngrams. Palin-dromes are texts that read the same both ways. Short palindromes (" race car ") usually carry precise , significant meanings. Long palindromes are often less meaningful, but even harder to generate. The palindrome generation problem has never been addressed, to our knowledge, from a strictly combinatorial point of view. The main difficulty is that generating palindromes require the simultaneous consideration of two interrelated levels in a sequence: the " character " and the " word " levels. Although the problem seems very combina-torial, we propose an elegant yet non-trivial graph structure that can be used to generate all possible palindromes from a given corpus of Ngrams, with a linear complexity. We illustrate our approach with short and long palindromes obtained from the Google Ngram corpus. We show how we can control the semantics, to some extent, by using arbitrary text corpora to bias the probabilities of certain sets of words. More generally this work addresses the issue of modelling human virtuosity from a combinatorial viewpoint, as a means to understand human creativity

    Convergent synthesis of digitally-encoded poly(alkoxyamine amide)s

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    International audiencea Binary-encoded poly(alkoxyamine amide)s were prepared by oligomer ligation. These polymers contain digital sequences based on two monomers defined as 0 and 1 bits. A library of oligomers containing all possible dyads 00, 01, 10 and 11 was prepared and used to construct long coded sequences

    Government Geoscience Stimulates Mineral Exploration in the Superior Province, Northern Québec

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    This paper summarizes new geologic information, and highlights exploration opportunities in the northeastern part of the Superior Province since 1997, as a result of the Far North Program undertaken by Géologie Québec. The first phase of the program was a regional lake-sediment geochemical survey, where 26,000 samples were collected north of 55°N from an area of approximately 350,000 km2. The resulting database attracted many mining companies to the region and led to numerous mineral discoveries. The second phase, started in 1998, consisted of extensive geological mapping, supplemented by U-Pb geochronological work; by 2003, more than twenty, 1:250,000 mapping projects were completed. The Far North Program is now in its final phase and it will produce a comprehensive geological and metallogenic synthesis of the new data from the areas surveyed. About forty previously unknown volcano-sedimentary belts, numerous mafic-ultramafic intrusions and sixteen different mineral deposit types have been identified. Since 1997, this has resulted in a surge of exploration activity that has seen more than 38millioninexpendituresbyprivateindustry.SOMMAIRELepreˊsentarticlepreˊsenteunreˊsumeˊdesnouvellesinformationsgeˊologiquesdisponiblesetdeˊcritdesciblesdexplorationmisesaujourdepuis1997danslenordestdelaProvincedulacSupeˊrieuretquideˊcoulentduprogrammedexplorationduGrandNorddeGeˊologieQueˊbec.Lapremieˋreeˊtapedeceprogrammeaconsisteˊenuneˊchantillonnagegeˊochimiquereˊgionaldeseˊdimentslacustres,ouˋ26000eˊchantillonsonteˊteˊpreˊleveˊsaunorddu55eparalleˋle,surunesuperficiedepreˋsde350000km2.Labasededonneˊesainsiconstitueˊeaattireˊdenombreusessocieˊteˊsminieˋresdanslareˊgionetdenombreusesdeˊcouvertesmineˊralesonteˊteˊfaites.Amorceˊeen1998,ladeuxieˋmeeˊtapeaconsisteˊenunecartographiegeˊologiquesysteˊmatique,appuyeˊepardesdatationsgeˊochronologiquesUPb.Et,en2003,plusde20cartesaˋleˊchelle1:250000avaienteˊteˊcompleˊteˊes.LeprogrammeduGrandNordenestmaintenantaˋsadernieˋreeˊtape,laquelleaboutiraaˋlaproductiondunesyntheˋsegeˊologiqueetmeˊtallogeˊniqueaˋpartirdesnouvellesdonneˊesprovenantdesreˊgionseˊtudieˊes.Environunequarantainedebandesvolcanoseˊdimentaires,denombreusesintrusionsmafiquesetultramatiques,etseizetypesdegisementsmineˊralogiquesdiffeˊrentsyonteˊteˊdeˊcrits.Depuis1997,ceprogrammeaentraı^neˊdesinvestissementsdexplorationparlentreprisepriveˊedeˊpassantles38M38 million in expenditures by private industry. SOMMAIRE Le présent article présente un résumé des nouvelles informations géologiques disponibles et décrit des cibles d'exploration mises au jour depuis 1997 dans le nord-est de la Province du lac Supérieur et qui découlent du programme d'exploration du Grand Nord de Géologie Québec. La première étape de ce programme a consisté en un échantillonnage géochimique régional de sédiments lacustres, où 26 000 échantillons ont été prélevés au nord du 55e parallèle, sur une superficie de près de 350 000 km2. La base de données ainsi constituée a attiré de nombreuses sociétés minières dans la région et de nombreuses découvertes minérales ont été faites. Amorcée en 1998, la deuxième étape a consisté en une cartographie géologique systématique, appuyée par des datations géochronologiques U-Pb. Et, en 2003, plus de 20 cartes à l'échelle 1:250 000 avaient été complétées. Le programme du Grand Nord en est maintenant à sa dernière étape, laquelle aboutira à la production d'une synthèse géologique et métallogénique à partir des nouvelles données provenant des régions étudiées. Environ une quarantaine de bandes volcano-sédimentaires, de nombreuses intrusions mafiques et ultramatiques, et seize types de gisements minéralogiques différents y ont été décrits. Depuis 1997, ce programme a entraîné des investissements d'exploration par l'entreprise privée dépassant les 38 M

    BMP-2 functions independently of SHH signaling and triggers cell condensation and apoptosis in regenerating axolotl limbs

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    <p>Abstract</p> <p>Background</p> <p>Axolotls have the unique ability, among vertebrates, to perfectly regenerate complex body parts, such as limbs, after amputation. In addition, axolotls pattern developing and regenerating autopods from the anterior to posterior axis instead of posterior to anterior like all tetrapods studied to date. Sonic hedgehog is important in establishing this anterior-posterior axis of limbs in all tetrapods including axolotls. Interestingly, its expression is conserved (to the posterior side of limb buds and blastemas) in axolotl limbs as in other tetrapods. It has been suggested that <it>BMP-2 </it>may be the secondary mediator of sonic hedgehog, although there is mounting evidence to the contrary in mice. Since <it>BMP-2 </it>expression is on the anterior portion of developing and regenerating limbs prior to digit patterning, opposite to the expression of sonic hedgehog, we examined whether <it>BMP-2 </it>expression was dependent on sonic hedgehog signaling and whether it affects patterning of the autopod during regeneration.</p> <p>Results</p> <p>The expression of <it>BMP-2 </it>and <it>SOX-9 </it>in developing and regenerating axolotl limbs corresponded to the first digits forming in the anterior portion of the autopods. The inhibition of sonic hedgehog signaling with cyclopamine caused hypomorphic limbs (during development and regeneration) but did not affect the expression of <it>BMP-2 </it>and <it>SOX-9</it>. Overexpression of <it>BMP-2 </it>in regenerating limbs caused a loss of digits. Overexpression of <it>Noggin </it>(<it>BMP </it>inhibitor) in regenerating limbs also resulted in a loss of digits. Histological analysis indicated that the loss due to <it>BMP-2 </it>overexpression was the result of increased cell condensation and apoptosis while the loss caused by <it>Noggin </it>was due to a decrease in cell division.</p> <p>Conclusion</p> <p>The expression of <it>BMP-2 </it>and its target <it>SOX-9 </it>was independent of sonic hedgehog signaling in developing and regenerating limbs. Their expression correlated with chondrogenesis and the appearance of skeletal elements has described in other tetrapods. Overexpression of <it>BMP-2 </it>did not cause the formation of extra digits, which is consistent with the hypothesis that it is not the secondary signal of sonic hedgehog. However, it did cause the formation of hypomorphic limbs as a result of increased cellular condensation and apoptosis. Taken together, these results suggest that <it>BMP-2 </it>does not have a direct role in patterning regenerating limbs but may be important to trigger condensation prior to ossification and to mediate apoptosis.</p

    MAPPING on UPMEM

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    This paper presents the implementation of a mapping algorithm on the UPMEM architecture. The mapping is a basic bioinformatics application that consists in finding the best location of millions of short DNA sequences on a full genome. The mapping can be constrained by a maximum number of differences between the DNA sequence and the region of the genome where a high similarity has been found. UPMEM’s Processing-In-Memory (PIM) solution consist of adding processing units into the DRAM, to minimize data access time and maximize bandwidth, in order to drastically accelerate data-consuming algorithms. A 16 GBytes UPMEM-DIMM module comes then with 256 UPMEM DRAM Processing Units (named DPU). The mapping algorithm implemented on the UPMEM architecture dispatches a huge index across the DPU memories. DNA sequences are assigned to a specific DPU according to k-mers features, allowing to massively map in parallel million of them. Experimentation on Human genome dataset shows that speed-up of 25 can be obtained with PIM, compared to fast mapping software such as BWA, Bowtie2 or NextGenMap running 16 Intel threads. Experimentation also highlight that data transfer from storage device limits the performances of the implementation. The use of SSD drives can boost the speed-up to 80

    Life in mine tailings: microbial population structure across the bulk soil, rhizosphere, and roots of boreal species colonizing mine tailings in northwestern Québec

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    Abstract Purpose Mining activities have negative effects on soil characteristics and can result in low pH, high heavy metal content, and limited levels of essential nutrients. A tailings storage area located in northwestern Québec showed natural colonization by plants from the adjacent natural environment. The objective of the study was to determine the main edaphic parameters that structured microbial populations associated with the indigenous woody plants that had naturally colonized the site. Methods Microbial populations were studied in the bulk soil, the rhizosphere, and inside plant roots using Illumina sequencing, ordination analysis (i.e., redundancy analysis (RDA) and principal coordinates analysis (PCoA)), ternary plotting, and statistical analysis (MANOVA). Results The main variables that drove the microbial community patterns were plant species and the tailings pH. Indeed, the main bacterial classes were Gammaproteobacteria and Deltaproteobacteria in both the rhizosphere and root endosphere. Analysis revealed that some dominant operational taxonomic units (e.g., Pseudomonas sp., Acinetobacter sp., and Delftia sp.) were present in increased proportions in roots for each plant species under study. This study also revealed that many of the most abundant fungal genera (e.g., Claussenomyces, Eupenicillium, and Trichoderma) were more abundant in the rhizosphere than in the root endosphere. Conclusions This comprehensive study of the microbial community dynamics in the bulk soil, rhizosphere, and root endosphere of boreal trees and shrubs could be beneficial in facilitating the rehabilitation of disturbed ecosystems
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