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Chapter 3 : Regulatory and Institutional Entrepreneurship: A Cross-Review of Law & Management Insights
No full textInternational audienceThe concept of “regulatory entrepreneurship” was coined by Pollman and Barry to characterize the business strategies that change existing regulatory frameworks to increase future opportunities or maintain current business activities. The rapid expansion of this stream of literature not only echoes the copious news items concerning lobbying operations, but also the rise of platform business models, operating in legal grey areas and whose influence strategies are still controversial. From this perspective, scholars from both law and business management backgrounds have endeavored to describe the different strategies deployed by regulatory entrepreneurs, their implementation process as well as the institutional conditions favoring their emergence. In this chapter, as a response, we the author offers a cross-literature review of these concepts of ‘regulatory entrepreneurship’ and “institutional entrepreneurship.” This systemic review on institutional entrepreneurship enables us to unpacks its main conceptual properties, in comparison with regulatory entrepreneurship, and presents four areas of cross-fertilization: understanding agency, power dynamics, hybridization processes, and the complexity of institutional change. We The chapter also argues that future research should further explore the dynamic interaction between different strategies promoted by institutional entrepreneurs, considering that regulatory entrepreneurship appears as embedded in a wider complex network of institutional initiatives. Accordingly, this chapter offers a research agenda to build upon the complementarities of those literatures
Isometric path complexity of graphs
No full textInternational audienceA set of isometric paths of a graph is "-rooted", where is a vertex of , if is one of the end-vertices of all the isometric paths in . The isometric path complexity of a graph , denoted by , is the minimum integer such that there exists a vertex satisfying the following property: the vertices of any isometric path of can be covered by many -rooted isometric paths. First, we provide an -time algorithm to compute the isometric path complexity of a graph with vertices and edges. Then we show that the isometric path complexity remains bounded for graphs in three seemingly unrelated graph classes, namely, hyperbolic graphs, (theta, prism, pyramid)-free graphs, and outerstring graphs. Hyperbolic graphs are extensively studied in Metric Graph Theory. The class of (theta, prism, pyramid)-free graphs are extensively studied in Structural Graph Theory, e.g. in the context of the Strong Perfect Graph Theorem. The class of outerstring graphs is studied in Geometric Graph Theory and Computational Geometry. Our results also show that the distance functions of these (structurally) different graph classes are more similar than previously thought. There is a direct algorithmic consequence of having small isometric path complexity. Specifically, we show that if the isometric path complexity of a graph is bounded by a constant, then there exists a polynomial-time constant-factor approximation algorithm for ISOMETRIC PATH COVER, whose objective is to cover all vertices of a graph with a minimum number of isometric paths. This applies to all the above graph classes
Diffusive gradient in thin film for ultra-trace methylmercury measurements in the coastal and open sea
No full textInternational audienceMonomethylmercury (MMHg) is a potent neurotoxin causing neurodevelopmental delays and cardiovascular and immunological issues. Human exposure primarily occurs through seafood consumption due to MMHg bioaccumulation and biomagnification from seawater into marine organisms. Determining MMHg in seawater at ultratrace concentrations poses logistical and analytical challenges. Diffusive Gradient in Thin-film (DGT) samplers represent a promising solution, which captures time-averaged concentrations by preconcentrating in situ MMHg over a defined exposure time. DGT manufactured with 3-mercaptopropyl-functionalized silica (3MFS) in agarose and polyacrylamide gels were tested and compared for the determination of MMHg present in open ocean and coastal waters. Different elution methods using acidic thiourea were tested to reach precise, accurate and quantitative elution of MMHg from the binding gel. We found that polyacrylamide-3MFS binding gels display a higher elution efficiency (94 ± 3 %), precision and better handling compared to agarose-3MFS gels (41 ± 6 %). A unique mooring line installed in the South Western Tropical Pacific Ocean, provided monthly DGT-MMHg concentrations over a year showing potential seasonal differences in MMHg concentrations ranging between 18 and 106 fM. DGT were also deployed in shallow Peruvian coastal waters, exhibiting higher MMHg concentrations (170 ± 97, n = 26) with typical benthopelagic gradients. DGT-MMHg concentrations were in good agreement with discrete water samples analyzed by reference methods using isotope dilution. DGTs offer complementary advantages over oceanographic cruises, notably in situ preconcentration, low blanks, minimal logistical requirements and cost-effectiveness. DGTs represent a valuable tool for studying the marine MMHg cycle for evaluating the implementation of the Minamata Convention
Platinum and Rare Earth Elements distribution in costal sediments from French western Mediterranean Sea
No full textInternational audienceThis study presents the first assessment of Technological Critical Elements (TCE), specifically platinum (Pt) and rare earth elements (REE), in coastal sediments along the French western Mediterranean Sea. These trace elements, increasingly used in advanced technologies, raise particular concerns due to their potential environmental impact. Surface sediment samples were collected from 21 stations along the French Mediterranean coast (from Spain border to Italy including Corsica Island) to evaluate TCE concentrations and identify potential sources. Most of the REE concentrations fell within expected natural levels and were mainly influenced by the geological characteristics of local watersheds, indicating a dominant geogenic origin. When normalized to European Shale, REE distribution patterns exhibited convex shapes, typical of coastal environments. In contrast, localized Pt enrichment were detected at specific sites, particularly in port areas, which could be linked to anthropogenic emissions from vehicular catalytic converters. These results highlight platinum as a relevant emerging contaminant in urban coastal environments. However, unexpected REE and Pt concentrations at the mouth of the Hérault river call for further investigation. This study highlights the importance of integrating geological background and anthropogenic pressures in coastal sediment quality assessments and supports the inclusion of TCE in long -term environmental monitoring programs in the Mediterranean Sea
Culturable macroplastic-associated potential human pathogens in coral reef lagoons, Madagascar
No full textInternational audiencePotentially human pathogenic bacteria (PHPBs) have been detected in plastic-associated marine microbiomes, primarily through DNA-based methods. However, data on their culturability and concentrations on plastics remain limited, yet are essential to assess actual health risks. To address this gap, 70 floating macroplastic and 20 seawater samples were collected from two human-impacted reef lagoons in southwestern Madagascar (AtsimoAndrefana region). PHPBs were cultured from their microbiomes using selective media and quantified. Macroplastics were predominantly polypropylene (34 %) and polyamide (31 %). In increasing order of concentration, four culturable PHPBs, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Vibrio Harveyi clade species, were identified on both macroplastics and in seawater, across all sites and polymer types. Notably, 52 % of macroplastic samples harbored two PHPB species simultaneously, while only 7 % were PHPB-free. Concentrations of all PHPBs were consistently and significantly higher on macroplastics than in seawater, regardless of the measurement unit or polymer type, with the Vibrio Harveyi clade being the most abundant. No significant correlations were observed among PHPB species concentrations, suggesting limited interaction and independent colonization. These findings indicate that floating macroplastics may serve as reservoirs and fomites for viable PHPBs. However, their potential impacts on ecosystems and human health should be interpreted cautiously. We emphasize the need to contextualize PHPB concentration data by considering factors such as exposure pathways, environmental persistence, and bacterial virulence, rather than relying solely on concentration-based comparisons, which may lead to misinterpretatio
Culturable macroplastic-associated potential human pathogens in coral reef lagoons, Madagascar
No full textInternational audiencePotentially human pathogenic bacteria (PHPBs) have been detected in plastic-associated marine microbiomes, primarily through DNA-based methods. However, data on their culturability and concentrations on plastics remain limited, yet are essential to assess actual health risks. To address this gap, 70 floating macroplastic and 20 seawater samples were collected from two human-impacted reef lagoons in southwestern Madagascar (Atsimo-Andrefana region). PHPBs were cultured from their microbiomes using selective media and quantified. Macroplastics were predominantly polypropylene (34 %) and polyamide (31 %). In increasing order of concentration, four culturable PHPBs, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Vibrio Harveyi clade species, were identified on both macroplastics and in seawater, across all sites and polymer types. Notably, 52 % of macroplastic samples harbored two PHPB species simultaneously, while only 7 % were PHPB-free. Concentrations of all PHPBs were consistently and significantly higher on macroplastics than in seawater, regardless of the measurement unit or polymer type, with the Vibrio Harveyi clade being the most abundant. No significant correlations were observed among PHPB species concentrations, suggesting limited interaction and independent colonization. These findings indicate that floating macroplastics may serve as reservoirs and fomites for viable PHPBs. However, their potential impacts on ecosystems and human health should be interpreted cautiously. We emphasize the need to contextualize PHPB concentration data by considering factors such as exposure pathways, environmental persistence, and bacterial virulence, rather than relying solely on concentration-based comparisons, which may lead to misinterpretation
High-Temperature Scanning Indentation : une méthode rapide pour quantifier les cinétiques de restauration des métaux
No full textInternational audienceA new technique called High-Temperature Scanning Indentation (HTSI) is proposed to study metallurgical evolution occurring during anisothermal heat treatments. This technique relies on high-speed nanohardness measurements performed during linear thermal ramping of the system with appropriatesettings. A specific high-speed loading procedure, based on a half-sine loading function, a creep segment, and a three-step unloading method, enables the measurement of elastic, plastic, and creep properties. The indentation cycle lasts one second to minimize thermal drift issues. This approach allowsquasi-continuous measurements of elastic modulus and hardness as a function of temperature in significantly shorter times compared to previous techniques. After validation, the HTSI method is applied to cold-rolled samples of commercially pure aluminum and oxygen-free high conductivity (OFHC) copper. The observed variations in hardness during heating are attributed to underlying restoration mechanisms, namely static recovery and recrystallization. Inverse analyses are performed using established metallurgical models of restoration. These results demonstrate the capability of the HTSI method to quantify restoration parameters as a function of temperature through a limited number of well-designed HTSI experiments. These conclusions are corroborated by EBSD analyses.Une nouvelle technique nommée High-Temperature Scanning Indentation (HTSI), est proposée pour étudier l’évolution métallurgique survenant lors de traitements thermiques anisothermes. Cette technique repose sur l’utilisation de mesures de nanodureté à grande vitesse effectuées pendant une montée en température linéaire du système avec des paramètres appropriés. Une procédure de chargement spécifique à grande vitesse, basée sur une fonction de chargement en demi-sinus, un segment de fluage et une méthode de déchargement en trois étapes, permet de mesurer les propriétés élastiques, plastiques et de fluage. Le cycle d’indentation dure une seconde afin de minimiser les problèmes de dérive thermique. Cette approche permet des mesures quasi-continues du module d’élasticité et de la dureté en fonction de la température dans des délais beaucoup plus courts que les techniques précédentes. Après validation, la méthode HTSI est appliquée à des échantillons laminés à froid d’aluminium pur commercial et de cuivre à haute conductivité sans oxygène (OFHC). Les variations observées de dureté pendant le chauffage sont attribuées aux mécanismes de restauration sous-jacents, à savoir la restauration statique et la recristallisation. Des analyses inverses sont réalisées en utilisant des modèles métallurgiques établis de restauration. Ces résultats démontrent la capacité de la méthode HTSI à quantifier les paramètres de restauration en fonction de la température grâce à un nombre limité d’expériences HTSI bien conçues. Ces conclusions sont corroborées par des analyses EBSD
Synthesis, Crystal Structure, Thermal Behavior, and Magnetic Properties of a Tetranuclear Mn(II) Complex Bridged by End-to-End Dicyanamide
No full textInternational audienceA new tetranuclear compound [Mn4(o-vanilin)6(N(CN)2)2(MeOH)2] (1) has been synthesized under reflux and structurally characterized by elemental analysis, IR, conductance measurement, variable temperature magnetic measurement and single crystal. The complex (1) crystallizes in the triclinic space group P-1 with unit cell dimensions a = 9.1014 (4) Å, b = 11.1169 (4) Å, c = 14.8923 (4) Å, = 93.698 (3)°, = 96.960 (3)°, = 107.165 (3)°, V = 1421.07 (9) Å3, Z = 1, R1 = 0.0345 and wR2 = 0.0798. The compound consist of two units [Mn2(o-Vanilin)3(MeOH)] with double 1,5-1,-1- dicyanamide (1,5-1,-1- DCA) bridges between neighboring manganese(II) atoms. Two Mn(II) are situated in an O4N inner, while the two others Mn(II) are encapsulated by an O5N inner. The two pentacoordinated Mn(II) ions are situated in square pyramidal environment, while the hexacoordinated Mn(II) ions environment is best described as octahedral geometry. Thermogravimetric analyze of the complex were carried out at 20–800 °C and showed that the complex were decomposed into three steps. Variable-temperature (5-300 K) magnetic susceptibility data reveal the existence of weak antiferromagnetic interaction in complex 1. The magnetic behavior is explained by considering the exchange coupled manganese-radical system, which is subjected to the MnII-O-MnII intradimer interactions. The least-squares fitting of the data results J = -0.8. Negligible interdimer exchange via Mn-DCA-Mn (Mn∙∙∙Mn of 8.4530(5) Å) was observed
Gravity as a deformed topological gauge theory
No full textInternational audienceWe construct gauge theories on the Lorentzian and Lorentzgeometries (comprising dS and AdS spacetimes). This allows to retrieve a large class of gravitational theories, including MacDowellMansouri gravity and its topological extention to Loop Quantum Gravity via the Pontrjagin characteristic class. In particular cases, we show one can obtain a positive effective cosmological constant even in the case of an AdS spacetime. Finally, we prove that the resulting action functionals are asymptotically topological if one assumes a vanishing bare cosmological constant with gauge and matter fields having compact support, thus leading to a perturbative topological gauge theory in the bare cosmological constant