112 research outputs found

    Suspended micro-resonator fabrication: fusion bonding of Silicon Nitride interfaces

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    This project aims to prove of the feasibility of Silicon Fusion Bonding for fabrication of micro- capillaries for gas cooling down. An optimal recipe for Silicon Fusion Bonding is developed, consisting of four steps: RCA cleaning, surface activation with O2 plasma and rehydration, manual pre-bonding and final annealing. Also a study of the influence of the speed of annealing on the bonding strength is conducted

    Ecological effects of full and partial protection in the crowded Mediterranean Sea: a regional meta-analysis

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    Marine protected areas (MPAs) are a cornerstone of marine conservation. Globally, the number and coverage of MPAs are increasing, but MPA implementation lags in many human-dominated regions. In areas with intense competition for space and resources, evaluation of the effects of MPAs is crucial to inform decisions. In the human-dominated Mediterranean Sea, fully protected areas occupy only 0.04% of its surface. We evaluated the impacts of full and partial protection on biomass and density of fish assemblages, some commercially important fishes, and sea urchins in 24 Mediterranean MPAs. We explored the relationships between the level of protection and MPA size, age, and enforcement. Results revealed significant positive effects of protection for fisheries target species and negative effects for urchins as their predators benefited from protection. Full protection provided stronger effects than partial protection. Benefits of full protection for fish biomass were only correlated with the level of MPA enforcement; fish density was higher in older, better enforced, and - interestingly - smaller MPAs. Our finding that even small, well-enforced, fully protected areas can have significant ecological effects is encouraging for "crowded" marine environments. However, more data are needed to evaluate sufficient MPA sizes for protecting populations of species with varying mobility levels

    Comparaison de la structure des peuplements de poissons et des processus Ă©cologiques sous- jacents, entre les forĂȘts de Cystoseires et des habitats structurellement moins complexes, dans l'Infralittoral rocheux de MĂ©diterranĂ©e nord-occidentale

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    In Mediterranean rocky subtidal, large brown algae belonging to the genus Cystoseira form structurally complex habitats, called Cystoseira forest. Due to anthropogenic stressors, Cystoseira forests disappeared from numerous localities in the Mediterranean Sea and are deteriorating in other localities. Cystoseira forests are usually replaced by structurally less complex habitats, such as shrublands, turfs and barren. This PhD aimed to assess putative consequences for fish of Cystoseira forest degradation, and to identify the underlying ecological processes. Multiple complementary approaches were used: macroalgae and fish field surveys, tank-based predation and habitat-choice experiments, stable isotopes and stomach contents analyses. Densities of prey and predatory fish were higher in Cystoseira forests compared to structurally less complex habitats. This may be due to the shelter role of Cystoseira spp. that induces (1) reduced mortality of prey and predatory fish in forests, due to high shelter and food availability, respectively, and (2) net immigration of fish into forests due to their preference for this structurally complex habitat. Moreover, Cystoseira spp. may be an important source of organic matter to the ecosystem. This possible trophic role deserves complementary studies. This work suggests that Cystoseira forest degradation are harmful to fish and from this perspective stresses the need to better manage human activities impacting Cystoseira spp.Dans l'Infralittoral rocheux mĂ©diterranĂ©en, les algues brunes du genre Cystoseira forment des habitats structurellement complexes, dĂ©nommĂ©s forĂȘts Ă  Cystoseira. A cause de certaines activitĂ©s anthropiques, ces forĂȘts ont dĂ©jĂ  disparu dans de nombreuses localitĂ©s et sont en train de rĂ©gresser dans d'autres. Elles ont Ă©tĂ© (sont) gĂ©nĂ©ralement remplacĂ©es par des habitats structurellement moins complexes de type brousse, gazon ou dĂ©sert. Cette thĂšse a visĂ© Ă  estimer les possibles consĂ©quences pour les poissons de la rĂ©gression des forĂȘts Ă  Cystoseira et Ă  identifier les processus Ă©cologiques en cause. Plusieurs approches complĂ©mentaires ont Ă©tĂ© employĂ©es : inventaires de macroalgues et de poissons, expĂ©riences de prĂ©dation et de sĂ©lection d'habitats en aquarium, analyses de composions isotopiques et de contenus stomacaux. Les densitĂ©s de poissons proie et prĂ©dateur Ă©taient plus importantes dans les forĂȘts Ă  Cystoseira que dans les habitats structurellement moins complexes. Cela peut rĂ©sulter, au moins en partie, du rĂŽle "refuge" de Cystoseira spp. qui induit (1) une plus faible mortalitĂ© des poissons proies et prĂ©dateurs dans les forĂȘts, due Ă  une plus grande disponibilitĂ© en abris et en nourriture, respectivement, (2) une immigration nette des poissons dans les forĂȘts due Ă  leur prĂ©fĂ©rence pour cet habitat structurellement complexe. De plus, Cystoseira spp. pourrait ĂȘtre une importante source de matiĂšre organique pour l'Ă©cosystĂšme. Ce potentiel rĂŽle trophique mĂ©rite des Ă©tudes complĂ©mentaires. Ce travail suggĂšre que la rĂ©gression des forĂȘts Ă  Cystoseira est nĂ©faste pour les poissons et souligne donc la nĂ©cessitĂ© de mieux gĂ©rer les activitĂ©s humaines impactant Cystoseira spp

    Comparison of fish assemblage structure and underlying ecological processes, between Cystoseira forests and less structurally complex habitats of North-Western Mediterranean rocky subtidal

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    Dans l'Infralittoral rocheux mĂ©diterranĂ©en, les algues brunes du genre Cystoseira forment des habitats structurellement complexes, dĂ©nommĂ©s forĂȘts Ă  Cystoseira. A cause de certaines activitĂ©s anthropiques, ces forĂȘts ont dĂ©jĂ  disparu dans de nombreuses localitĂ©s et sont en train de rĂ©gresser dans d'autres. Elles ont Ă©tĂ© (sont) gĂ©nĂ©ralement remplacĂ©es par des habitats structurellement moins complexes de type brousse, gazon ou dĂ©sert. Cette thĂšse a visĂ© Ă  estimer les possibles consĂ©quences pour les poissons de la rĂ©gression des forĂȘts Ă  Cystoseira et Ă  identifier les processus Ă©cologiques en cause. Plusieurs approches complĂ©mentaires ont Ă©tĂ© employĂ©es : inventaires de macroalgues et de poissons, expĂ©riences de prĂ©dation et de sĂ©lection d'habitats en aquarium, analyses de composions isotopiques et de contenus stomacaux. Les densitĂ©s de poissons proie et prĂ©dateur Ă©taient plus importantes dans les forĂȘts Ă  Cystoseira que dans les habitats structurellement moins complexes. Cela peut rĂ©sulter, au moins en partie, du rĂŽle "refuge" de Cystoseira spp. qui induit (1) une plus faible mortalitĂ© des poissons proies et prĂ©dateurs dans les forĂȘts, due Ă  une plus grande disponibilitĂ© en abris et en nourriture, respectivement, (2) une immigration nette des poissons dans les forĂȘts due Ă  leur prĂ©fĂ©rence pour cet habitat structurellement complexe. De plus, Cystoseira spp. pourrait ĂȘtre une importante source de matiĂšre organique pour l'Ă©cosystĂšme. Ce potentiel rĂŽle trophique mĂ©rite des Ă©tudes complĂ©mentaires. Ce travail suggĂšre que la rĂ©gression des forĂȘts Ă  Cystoseira est nĂ©faste pour les poissons et souligne donc la nĂ©cessitĂ© de mieux gĂ©rer les activitĂ©s humaines impactant Cystoseira spp.In Mediterranean rocky subtidal, large brown algae belonging to the genus Cystoseira form structurally complex habitats, called Cystoseira forest. Due to anthropogenic stressors, Cystoseira forests disappeared from numerous localities in the Mediterranean Sea and are deteriorating in other localities. Cystoseira forests are usually replaced by structurally less complex habitats, such as shrublands, turfs and barren. This PhD aimed to assess putative consequences for fish of Cystoseira forest degradation, and to identify the underlying ecological processes. Multiple complementary approaches were used: macroalgae and fish field surveys, tank-based predation and habitat-choice experiments, stable isotopes and stomach contents analyses. Densities of prey and predatory fish were higher in Cystoseira forests compared to structurally less complex habitats. This may be due to the shelter role of Cystoseira spp. that induces (1) reduced mortality of prey and predatory fish in forests, due to high shelter and food availability, respectively, and (2) net immigration of fish into forests due to their preference for this structurally complex habitat. Moreover, Cystoseira spp. may be an important source of organic matter to the ecosystem. This possible trophic role deserves complementary studies. This work suggests that Cystoseira forest degradation are harmful to fish and from this perspective stresses the need to better manage human activities impacting Cystoseira spp

    Rapid Multianalyte Microfluidic Homogeneous Immunoassay on Electrokinetically Driven Beads

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    The simplicity of homogeneous immunoassays makes them suitable for diagnostics of acute conditions. Indeed, the absence of washing steps reduces the binding reaction duration and favors a rapid and compact device, a critical asset for patients experiencing life-threatening diseases. In order to maximize analytical performance, standard systems employed in clinical laboratories rely largely on the use of high surface-to-volume ratio suspended moieties, such as microbeads, which provide at the same time a fast and efficient collection of analytes from the sample and controlled aggregation of collected material for improved readout. Here, we introduce an integrated microfluidic system that can perform analyte detection on antibody-decorated beads and their accumulation in confined regions within 15 min. We employed the system to the concomitant analysis of clinical concentrations of Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Cystatin C in serum, two acute kidney injury (AKI) biomarkers. To this end, high-aspect-ratio, three-dimensional electrodes were integrated within a microfluidic channel to impart a controlled trajectory to antibody-decorated microbeads through the application of dielectrophoretic (DEP) forces. Beads were efficiently retained against the fluid flow of reagents, granting an efficient on-chip analyte-to-bead binding. Electrokinetic forces specific to the beads’ size were generated in the same channel, leading differently decorated beads to different readout regions of the chip. Therefore, this microfluidic multianalyte immunoassay was demonstrated as a powerful tool for the rapid detection of acute life-threatening conditions

    Analyse comparative en imagerie de la leucoencéphalopathie multifocale progressive selon la pathologie sous-jacente : à propos de 15 cas

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    La LeucoencĂ©phalopathie Multifocale Progressive (LEMP) est une pathologie dĂ©myĂ©linisante grave du systĂšme nerveux central liĂ©e Ă  la rĂ©activation du JC virus en cas d immunodĂ©pression. La LEMP concerne principalement les sujets infectĂ©s par le Virus d ImmunodĂ©ficience Humaine (VIH) mais Ă©galement ceux atteints de maladies systĂ©miques et hĂ©matologiques ou sous immunosuppresseurs. Le but de cette Ă©tude est d Ă©valuer si la LEMP prĂ©sente des caractĂ©ristiques particuliĂšres en Imagerie par RĂ©sonance MagnĂ©tique (IRM) conventionnelle selon l origine de l immunodĂ©pression. 15 patients ont Ă©tĂ© rĂ©partis en 3 groupes en fonction de la pathologie responsable de la LEMP. Le premier groupe est composĂ© de 9 sujets atteints du VIH, le 2Ăšme groupe de 4 sujets atteints de maladies systĂ©miques, hĂ©matologiques ou inconnue et le 3Ăšme groupe est constituĂ© de 2 sujets atteints de SclĂ©rose En Plaques (SEP) sous natalizumab. Pour chaque cas de LEMP, l analyse des IRM a permis d Ă©tudier Ă  la fois le nombre des lĂ©sions, leur localisation, l aspect en pondĂ©ration T1, T2 et diffusion/Coefficient Apparent de Diffusion (ADC), l effet de masse, l atteinte de la substance grise, la prise de contraste et l Ă©volution. Cette Ă©tude montre que les lĂ©sions de LEMP sont uni- ou multifocales sans distinction selon les groupes. Elles sont toujours en hyposignal T1 et hypersignal T2, ont le mĂȘme aspect en ADC et n exercent pas d effet de masse. Elles n atteignent que rarement la substance grise, uniquement au cours de leur Ă©volution et ne se rehaussent qu exceptionnellement. Outre l atteinte insulaire qui ne concerne que les patients du groupe 2, la LEMP conserve le mĂȘme aspect quelle qu en soit sa cause. Le pronostic est plus sombre en cas de pathologie systĂ©mique, hĂ©matologique ou inconnue qu en cas de VIH ou de SEP sous natalizumab. Les diagnostics diffĂ©rentiels sont rares, ils peuvent ĂȘtre affinĂ©s grĂące Ă  la spectroscopie par rĂ©sonance magnĂ©tique et le transfert de magnĂ©tisation. Le tenseur de diffusion apparaĂźt ĂȘtre un moyen de dĂ©celer la LEMP prĂ©cocement. Actuellement, le seul traitement efficace est celui de la cause, expliquant la diffĂ©rence de pronostic entre les diffĂ©rents groupes, mais il y a un risque d Ă©volution vers un Syndrome Inflammatoire de Reconstitution Immunitaire (IRIS).DIJON-BU MĂ©decine Pharmacie (212312103) / SudocSudocFranceF

    Méthode d'optimisation pour l'élaboration de réseaux de micro digesteurs anaérobies pour le traitement décentralisé des biodéchets en milieu urbain et périurbain

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    International audienceInnovative small scale treatments solutions are currently proposed to handle the growing need of biowaste valorization through a more circular economy. These new approaches are designed to be embedded in a decentralized treatment scheme which raises new challenges for the biowaste management at the territorial scale. This study, aimed at developing a method to design decentralized and micro-scale Anaerobic Digestion (mAD) networks in urban and peri-urban areas. A mixed integer linear program (MILP) was set up to identify the number of mAD, their sites and their capacities in order to minimize the payload-distances of biowaste and digestate transportation while taking into account the technical constraints of the system. A Geographic Information System (GIS) methodology was developed to feed the MILP model with very fine-scale data about (1) the location and the characterization of the biowaste sources and of the digestate outlets (agricultural areas), and (2) the location of the potential sites for mAD based on a multi-criteria analysis that includes environmental regulations, urban planning rules, site accessibility and heat outlets for valorization. The method was applied to the territory of The Grand Lyon Metropole (534 km2) in France. Optimized mAD networks were identified through the MILP according to different scenarios tested

    Recensement des dispositifs de suivis poissons dans les Aires Marines Protégées de Méditerranée Française

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    Ce document constitue la synthĂšse du recensement des suivis de l’ichtyofaune menĂ©s dans les Aires Marines ProtĂ©gĂ©es de MĂ©diterrannĂ©e Occidentale (MO) française.En vue de l’élaboration d’une stratĂ©gie de surveillance nationale des poissons et cĂ©phalopodes en milieux cĂŽtiers, un recensement des suivis existants hors cadre DCSMM, a Ă©tĂ© rĂ©alisĂ© en 2022. Un certain nombre de dispositifs mis en oeuvre dans les AMP de MO ont Ă©tĂ© identifiĂ©s comme pouvant potentiellement contribuer Ă  la fourniture de donnĂ©es utiles pour l’évaluation DCSMM.L’analyse comparative des diffĂ©rents suivis menĂ©s dans les AMP met en Ă©vidence le fait que les cinq grandes familles de suivis (UVC transect, UVC temps, pĂȘche scientifique, pĂȘche de loisirs et pĂȘche professionnelle) sont globalement bien reprĂ©sentĂ©es Ă  l’échelle de la façade mais mises en oeuvre selon des stratĂ©gies d’échantillonnage (saison, surface, nombre de rĂ©plicats,
) hĂ©tĂ©rogĂšnes. A ce stade, cette hĂ©tĂ©rogĂ©nĂ©itĂ© remet en question l’inter-comparabilitĂ© des jeux de donnĂ©es et leur utilisation pour la DCSMM.Compte tenu de la forte reprĂ©sentativitĂ© des suivis UVC transect au sein des diffĂ©rents AMP et de l’antĂ©rioritĂ© des donnĂ©es disponibles, il semble essentiel de travailler dans un premier temps sur ces protocoles en Ă©valuant la faisabilitĂ© de la mise en place d’un protocole d’échantillonnage standardisĂ© rĂ©pondant aux besoins des gestionnaires et Ă  ceux des directives publiques
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