5,533 research outputs found

    Past volcanic activity predisposes an endemic threatened seabird to negative anthropogenic impacts

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    International audienceAbstract Humans are regularly cited as the main driver of current biodiversity extinction, but the impact of historic volcanic activity is often overlooked. Pre-human evidence of wildlife abundance and diversity are essential for disentangling anthropogenic impacts from natural events. Réunion Island, with its intense and well-documented volcanic activity, endemic biodiversity, long history of isolation and recent human colonization, provides an opportunity to disentangle these processes. We track past demographic changes of a critically endangered seabird, the Mascarene petrel Pseudobulweria aterrima , using genome-wide SNPs. Coalescent modeling suggested that a large ancestral population underwent a substantial population decline in two distinct phases, ca. 125,000 and 37,000 years ago, coinciding with periods of major eruptions of Piton des Neiges. Subsequently, the ancestral population was fragmented into the two known colonies, ca. 1500 years ago, following eruptions of Piton de la Fournaise. In the last century, both colonies declined significantly due to anthropogenic activities, and although the species was initially considered extinct, it was rediscovered in the 1970s. Our findings suggest that the current conservation status of wildlife on volcanic islands should be firstly assessed as a legacy of historic volcanic activity, and thereafter by the increasing anthropogenic impacts, which may ultimately drive species towards extinction

    Current state-of-the-art and gaps in platform trials: 10 things you should know, insights from EU-PEARL

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    Summary: Platform trials bring the promise of making clinical research more efficient and more patient centric. While their use has become more widespread, including their prominent role during the COVID-19 pandemic response, broader adoption of platform trials has been limited by the lack of experience and tools to navigate the critical upfront planning required to launch such collaborative studies. The European Union-Patient-cEntric clinicAl tRial pLatform (EU-PEARL) initiative has produced new methodologies to expand the use of platform trials with an overarching infrastructure and services embedded into Integrated Research Platforms (IRPs), in collaboration with patient representatives and through consultation with U.S. Food and Drug Administration and European Medicines Agency stakeholders. In this narrative review, we discuss the outlook for platform trials in Europe, including challenges related to infrastructure, design, adaptations, data sharing and regulation. Documents derived from the EU-PEARL project, alongside a literature search including PubMed and relevant grey literature (e.g., guidance from regulatory agencies and health technology agencies) were used as sources for a multi-stage collaborative process through which the 10 more important points based on lessons drawn from the EU-PEARL project were developed and summarised as guidance for the setup of platform trials. We conclude that early involvement of critical stakeholder such as regulatory agencies or patients are critical steps in the implementation and later acceptance of platform trials. Addressing these gaps will be critical for attaining the full potential of platform trials for patients. Funding: Innovative Medicines Initiative 2 Joint Undertaking with support from the European Union’s Horizon 2020 research and innovation programme and EFPIA

    L’apiculture, entre naturalisme et productivisme ? 

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    L’engouement pour le sort des abeilles serait-il en train de transformer l’image et le statut de l’apiculture ? Les discours autour de l’abeille domestique dĂ©ployĂ©s dans les mĂ©dias et exprimĂ©s parfois dans les programmes de dĂ©veloppement de l’apiculture rĂ©vĂšlent selon nous une tension entre une vision naturaliste et une vision productiviste. À partir de l’étude des apicultures corse et du Souss (Maroc) nous mettons au jour la diversitĂ© des formes d’organisation sociotechnique et des maniĂšres de produire des miels. Nous montrons que ces pĂŽles naturalistes et productivistes ne s’expriment pas clairement dans l’activitĂ© apicole elle-mĂȘme. Enfin, nous discutons cette tension au regard de la notion d’écologisation et de l’importance du cadre territorial dans lequel s’exerce l’activitĂ© apicole, afin de se dĂ©gager d’une vision gĂ©nĂ©rique et polarisĂ©e.The image and status of beekeeping is being transformed due to the worldwide enthusiasm for honeybees and concern for their future in our changing world. Yet media discussions about honeybees reveal a tension between naturalist and productivist visions of beekeeping, a tension also found in beekeeping development programs. While illustrating how diverse honey production and its socio-technical organization are, our study of Corsica (France) and Souss (Morocco) show that the naturalist/productivist polarization does not transpire in beekeeping itself. Finally, we discuss this tension in the light of ecologization and the importance of the territorial framework in which beekeeping is conducted, which provides a way of moving beyond a generic and polarized vision

    An Integrated Wind Turbine and Power Grid Model

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    Growing penetration of renewable sources of power generation around the world causes a decline in the inertia of power grids. This poses a direct risk to safe operation of power systems, as frequency stability becomes difficult to be maintained and managed. Being able to predict and react to grid frequency variations is crucial to ensure reliable supply of electricity. This paper developed an integrated model of wind turbine system with power grid model for frequency stability investigation with the objective to evaluate how renewable wind generation impacts the frequency stability. A model of the conventional 10 GW power generation system based on load frequency control (LFC) and automatic generation control (AGC) incorporated with 2 MW full power converter wind turbine, was demonstrated in this paper. The proposed model will demonstrate a loss of 1 GW of generation for a 10 GW grid, the model will then be examined and simulated to ensure the validity of the results. It has been concluded that load frequency control LFC was not able to restore system frequency to nominal on its own and automatic generation control AGC is needed to fully restore the 50 Hz of the grid

    Making Frugal Spatial Audio Systems Using Field-Programmable Gate Arrays

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    International audienceSpatial audio systems are expensive, mostly because they usually imply the use of a wide range of speakers and hence audio outputs. Some techniques such as Wave Field Synthesis (WFS) are especially demanding in that regard making them out of reach to many individuals or even institutions. In this paper, we propose to leverage recent progress made using Field-Programmable Gate Arrays (FPGA) in the context of real-time audio signal processing to implement frugal spatial audio systems. We focus on the case of WFS and we demonstrate how to build a 32 speakers system that can manage multiple sources in parallel for less than 800 USD (including speakers). We believe that this approach contributes to making advanced spatial audio techniques more accessible

    Volcanisme et tectonique le long de l'archipel des Comores (Canal Nord Mozambique) : Ă©tat d'avancement du projet ANR COYOTES

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    International audienceSuite Ă  l’initiation en mai 2018 de la crise sismo-volcanique de Mayotte qui a donnĂ© lieu, entre autre, Ă  une intense sismicitĂ© et Ă  la mise en place d’un nouvel Ă©difice volcanique sous-marin, Fani-MaorĂ©, Ă  50km Ă  l’Est de Mayotte, la communautĂ© scientifique s’est fortement impliquĂ©e. Un effort consĂ©quent a Ă©tĂ© rĂ©alisĂ© pour amĂ©liorer les connaissances gĂ©ologiques de ce territoire grĂące Ă  des projets de recherches, en parallĂšle de la surveillance de l’activitĂ© tellurique menĂ©e par le REVOSIMA (campagnes MAYOBS, DOI :10.18142/291).Le projet COYOTES (Comoros & maYotte: vOlcanism, TEctonics and Seismicity, 2020-2024), s’appuyant sur des donnĂ©es des campagnes ocĂ©anographiques de recherche SISMAORE (10.17600/18001331) et SCRATCH (DOI :10.17600/18002274), vise Ă  mieux comprendre le contexte gĂ©ologique et gĂ©odynamique du Canal nord Mozambique. Cela intĂšgre Ă  la fois l'Ă©volution et la rĂ©partition de l’activitĂ© volcanique, tectonique et sismologique ainsi que la cinĂ©matique et la caractĂ©risation des dĂ©pĂŽts sĂ©dimentaires et des structures crustales, Ă  court et Ă  long terme et aux Ă©chelles locale et rĂ©gionale. Nous proposons de prĂ©senter l’état d’avancement des travaux menĂ©s dans le cadre de cet ANR-COYOTES, spĂ©cifiquement sur la distribution spatiale des dĂ©formations actives et rĂ©centes le long de l'archipel des Comores (Thinon et al., 2022 ; Boymond et al., 2022 ; Mercury et al., 2022), sur les nouveaux Ăąges et la gĂ©ochimie des Ă©difices volcaniques et des iles (Rusquet et al., 2023), sur la caractĂ©risation des dĂ©pĂŽts volcano-dĂ©tritiques et des dĂ©stabilisations identifiĂ©es dans la plaine abyssale (Paquet et al., 2019). L’architecture du substratum sous le volcan Fani-MaorĂ© et la structuration crustale seront Ă©galement exposĂ©es (Canva et al., RST 2023; Masquelet et al., 2022; Rolandone et al., 2022 ; Watremez et al., RST 2023). Ce rĂ©sumĂ© est une contribution des Ă©quipes du projet COYOTES (ANR-19-CE31-0018), financĂ© par l’ANR et le BRGM (http://www.geocean.net/coyotes/doku.php?id=start)

    IPS-methode in Nederland

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    Nouvelles Questions féministes, 2020, 39 (1) : Partir de soi. Expériences et théorisation

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    La perspective critique du savoir, de son Ă©diction et des reprĂ©sentations qu’il sous-tend, est un Ă©lĂ©ment central de la pensĂ©e et des pratiques fĂ©ministes. Comme nous le rappellent en introduction les coordinatrices de ce numĂ©ro, Marie Mathieu, Vanina Mozziconacci, Lucile Ruault et Armelle Weil, les Ă©pistĂ©mologies fĂ©ministes du standpoint, ou « épistĂ©mologies situĂ©es », ont Ă©mergĂ© au cours des annĂ©es 1980-1990 Ă  divers endroits et dans diffĂ©rents champs disciplinaires. PensĂ©es comme un espace..

    Transformations sur les polynÎmes binaires irréductibles

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    Using the natural action of GL2(F2) S3 over F2[X], one can define different classes of polynomials strongly analogous to selfreciprocal irreducible polynomials. We give transformations to construct polynomials of each kind of invariance and we deal with the question of explicit infinite sequences of invariant irreducible polynomials in F2[X]. We generalize results obtained by Varshamov, Wiedemann, Meyn and Cohen and we give sequences of invariant irreducible polynomials. Moreover we explain what happens when the given constructions fail. We also give a result on the order of the polynomials of one of the classes: the alternate irreducible polynomials
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