HAL Portal UPF (Université de la Polynésie française)
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Sounds as taxonomic indicators in Holocentrid fishes
No full textInternational audienceThe species-specific character of sounds in the animal kingdom has been extensively documented, yet research on fishes has predominantly focused on a limited number of species, overlooking the potential of acoustic signals to reflect broader taxonomic ranks. In this study, we analyzed acoustic data of hand-held sounds from 388 specimens spanning 5 genera and 33 species within the family Holocentridae, with the objective of evaluating the use of sound characteristics for taxonomic discrimination across various levels (subfamily, genus, species). Sounds could be indicative of grouping. Taxa discriminability depends on taxonomic level; the higher the taxonomic level, the better the discrimination of taxa based on sounds. Analogous to the role of morphological traits in taxonomic delineation, this research corroborates the utility of acoustic features in identifying fish taxa across multiple hierarchical levels. Remarkably, certain holocentrid species have evolved complex sound patterns characterized by unique temporal arrangements where pulses are not continuous but emitted in blocks, facilitating the exploitation of the acoustic space
Conceptualization of territorial resilience potential indicators to coastal hazards through the use of unmanned aerial vehicles
No full textInternational audienceMajor natural hazards in recent decades have led to a revisiting of the concept of resilience, particularly in order to analyze traditional models of response to an unforeseen event and post-crisis management mechanisms. For resilience to be an applicable/operational concept to guide management and inform decisions, it must ultimately be characterized for its assessment. This assessment can be done through the identification of indicators specifically contextualized to the study site and object of study. However, today, operationalizing of the concept of resilience tends to draw on annual censuses or aggregated data, providing a generalized large scale view of the territorial resilience potential. The objective of this study is to identify a table of Territorial Resilience Potential (TRP) indicators to coastal hazards applied to coastal island territories, supplied by data from Unmanned Aerial Vehicles (UAVs) to allow for rapid and site specific data acquisition for repetitive surveys. This acquisition method makes it possible to calculate a number of relevant indicators for assessing the resilience potential of coastal areas. In particular, it allows rapid updating of data following major meteorological events and identification of hot and cold spots of resilience potential of a specific study site. To demonstrate the applicability of this method to island territories, the island of Bora Bora in French Polynesia was used as a case study. Finally, these kinds of results can be fed through a spatial decision support system to help decision-makers choose an adaptation and protection strategy in order to move towards resilient territories, over a long period of time
Au-delà du navire : la violence du Bounty racontée par James Norman Hall et Charles Nordhoff
No full textLe 23 décembre 1787, le HMS Bounty quitte l’Angleterre en Europe pour Tahiti, une île au milieu de l’océan Pacifique. Missionné par la British Royal Society et dirigé par le lieutenant William Bligh, son objectif consiste à récolter des arbres à pain à Tahiti pour les transplanter dans les colonies britanniques dans les Indes occidentales dans l’espoir de résoudre la famine qui sévit parmi la population d’esclaves travaillant dans les plantations de coton et de sucre de l’empire. De cette très célèbre expédition, le grand public retient notamment en premier la mutinerie qui éclata à son bord le 28 avril 1789 et qui opposa son commandant de bord, William Bligh, et son second, Fletcher Christian, puis l’exploit de Bligh et ses loyalistes qui ont navigué 3 500 miles nautiques1 pour rejoindre Kupang au Timor, alors une colonie européenne, dans l’espoir d’être sauvés et enfin le destin tragique des mutins à Pitcairn ayant réussi à échapper aux représailles de la Royal Navy jusqu’à la découverte de la petite colonie restante par le navire américain le Topaz en 1808
Experimental Analysis of a Compressor-Assisted Thermochemical Hybrid System Driven by Low Grade Heat Source for Cooling Applications
No full textInternational audienceThis study presents an experimental investigation that provides a proof of concept of an innovating thermochemical hybrid process introducing mechanical assistance to drive both charging (decomposition) and discharging (synthesis) phases to produce cold at lower temperatures than those achieved by conventional thermochemical chillers with lower heat source temperature than needed by conventional thermochemical chillers. The reagent used for this experiment is barium chloride (BaCl 2 ), which normally enables the production of air-conditioning cold. This study demonstrates that it is possible to achieve continuous cold production at lower temperatures. The experiments also show that the synthesis reaction occurs much faster when utilizing the compressor, primarily due to a larger gap between the thermodynamic equilibrium pressure and the actual operating pressure. The performance of various cycles, both with and without a compressor, was estimated by evaluating the system's coefficient of performance (COP) and exergy efficiency. The analysis revealed a decrease in COP when using the compressor. The results for exergy efficiency were more varied. Notably, the production of cold at lower temperatures significantly increased exergy efficiency, which indicates that the use of a compressor during the synthesis phase appears to be beneficial. For instance, in the assisted synthesis phase, it is possible to achieve cold production at 0°C (compared to 20°C without compressor) by utilizing a heat source at 70°C for the decomposition, resulting in a COP of 0.40 and an exergy efficiency of 0.15. Additionally, the assisted decomposition phase enables a reduction in the required driving heat source temperature to 54°C (while 70°C are needed without compressor). This leads to a system COP of 0.32 and an exergy efficiency of 0.09. At the end of a compressor-assisted synthesis process, the reactor retains a higher amount of sensible heat due to its operation at a higher temperature, unlike the classical synthesis process that operates at a temperature close to ambient temperature. Consequently, during a subsequent desorption phase, the reactor initiates at a higher temperature, avoiding the need for the heat source to pre-heat the reactor (provided that the reactor has not cooled down yet). This feature enables a more energy-efficient sequence between decomposition and synthesis, leading to improved system speed and overall performance.</div
Attribution de la NBI au sein du corps des infirmiers en soins généraux et spécialisés de la FPH : l'exclusion des infirmières puéricultrices est illégale
No full textInternational audienceNote sous TA Lyon, 19 décembre 2023, no 2104559, Hospices civils de Lyo
Behavioural heterogeneity across killer whale social units in their response to feeding opportunities from fisheries
No full textInternational audienceIntra‐population heterogeneity in the behavioural response of predators to changes in prey availability caused by human activities can have major evolutionary implications. Among these activities, fisheries, while extracting resources, also provide new feeding opportunities for marine top predators. However, heterogeneity in the extent to which individuals have responded to these opportunities within populations is poorly understood. Here, we used 18 years of photo‐identification data paired with statistical models to assess variation in the way killer whale social units within a subantarctic population (Crozet Islands) interact with fisheries to feed on fish caught on fishing gear (i.e., depredation behaviour). Our results indicate large heterogeneity in both the spatial and temporal extents of depredation across social units. While some frequently depredated on fishery catches over large areas, others sporadically did so and in small areas consistently over the years. These findings suggest that killer whale social units are exposed to varying levels of impacts of depredation, both negative (potential retaliation from fishers) and positive (food provisioning), on their life history traits, and may explain the contrasted demographic patterns observed within the declining population at Crozet but also potentially within the many other killer whale populations documented depredating on fisheries catches worldwide
3D microscopic reconstruction of pearls using combined optical microscopy and photogrammetry
No full textInternational audienceIn this study, we introduce an affordable and accessible method that combines optical microscopy and photogrammetry to reconstruct 3D models of Tahitian pearls. We present a novel device designed for acquiring microscopic images around a sphere using translational displacement stages and outline our method for reconstructing these images. We successfully created 3D models of two individual pearl rings, each representing 6.3% of the pearl’s surface. Additionally, we generated a combined model representing 10.3% of the pearl’s surface. This showcases the potential for reconstructing entire pearls with appropriate instrumentation. We emphasize that our approach extends beyond pearls and spherical objects and can be adapted for various object types using appropriate acquisition devices. We provide a proof of concept demonstrating the feasibility of 3D photogrammetry using optical microscopy. Consequently, our method offers a practical and cost-effective alternative for generating 3D models at a microscopic scale, particularly when detailed internal structure information is unnecessary
Les outils pour une bonne gouvernance, en vue d’aménagements fondés sur l’innovation et le développement durable
No full textInternational audienceThe aim of this research is to respond to expectations and demands in terms of governance for development projects. The study is based on the observation of two different eco-neighbourhood projects: in the first case, citizens grouped together and organised in self-development; in the second, the decision comes from a local authority in favour of the residents. The aim of the analysis is to demonstrate the relevance of the local scale in terms of regional planning, sustainable construction and collective participation.Cette recherche vise à répondre aux attentes et demandes en matière de gouvernance en vue de la réalisation de projets d’aménagement. L’étude repose sur l’observation de deux projets d’écoquartiers différents : dans le premier cas, il s’agit de citoyens regroupés et organisés en autopromotion, dans le second, la décision provient d’une collectivité territoriale en faveur des habitants. L’analyse vise à montrer la pertinence de l’échelle locale en matière d’aménagements du territoire, de constructions durables et de participations collectives