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Towards a sediment-based epidemiology ?
No full textInternational audienceSettling basins found in sewage networks mostly collect coarse particles [1]. This material accumulates priorto more or less regular cleaning, and one can consider that the particles accumulated between each cleaning,although coarse, record a molecular signal that reflects the contamination of the wastewater.With the very strong recent development of wastewater-based epidemiology, which consists in estimating theuses and health states of the population based on the wastewater chemical composition, the aim of this studyis to consider these sediment accumulations as archives of the latter.Several sediment cores were collected by gravity coring before cleaning in decantation tanks in Orléans andParis, France, in combined sewer networks. A total of 12 cores, sub-sampled into 200 samples, wererecovered.Samples were characterised by various methods to assess particle size distribution, total organic carbon andelemental composition. In addition, they were extracted with methanol by accelerated solvent extraction torecover the moderately polar organic molecules adsorbed on the particles. Analysis through liquidchromatography coupled with tandem mass spectrometry was used to detect 60 molecules (mostlypharmaceuticals and illicit drugs), 54 of which were quantified at least once.The analyses highlighted the very significant geochemical heterogeneity of the samples, within the same core,with 2 main types of facies, very coarse and mineral facies, and organic and less coarse facies [2]. These twofacies can be explained in particular by the two types of wastewater at the origin of these deposits, rainwaterin the case of the former, and black and grey waters in the case of the latter.This sedimentological heterogeneity also has an impact on the evolution of organic molecule content, with verydistinct levels between organic and mineral facies. These rapid and abrupt changes in content make directinterpretation of usage arduous.Two trends have been observed, with (i) neutral or negatively-charged molecules whose content is stronglycorrelated with total organic carbon, and (ii) positively-charged molecules whose content is uncorrelated [3].Therefore, before considering using this typology of sedimentary archives to retrospectively estimate the stateof health of populations, and in particular healthcare practices, some corrective work remains to be carried out.While for non-cationic molecules, normalization to organic carbon seems particularly promising, for cationicmolecules, the combined role of organic and mineral surfaces seems to play an important role in their affinitywith particulate material, making this normalization more difficult to achieve to reveal the full potential of thesearchives of everyday practices in the areas collected
Le début de la fin de la tripartition ? Élections européennes et inégalités sociales en France, 1994-2024
No full textCette étude analyse la structure du vote au niveau communal observé lors des élections européennes menées en France de 1994 à 2024. Nous proposons également une comparaison avec la structure des clivages sociaux et électoraux étudiée à partir des scrutins législatifs, présidentiels et référendaires dans notre ouvrage Une histoire du conflit politique. Élections et inégalités sociales en France, 1789-2022 (Le Seuil, 2023). De façon générale, la structure du vote aux scrutins européens suit des évolutions relativement proches de celles observées lors des élections législatives et présidentielles au cours des trente dernières années. On constate toutefois plusieurs inflexions récentes importantes, en particulier lors du scrutin européen de 2024. Tout d’abord, la chute du bloc libéral central à moins de 15% des voix confirme la fragilité du système de tripartition, en lien avec la base sociale très étroite et socialement très privilégiée de ce bloc électoral. On observe par ailleurs lors des élections européennes de 2024 un processus d’embourgeoisement du bloc national-libéral (RN, LR, Reconquête), ce qui conforte la possibilité d’une rebipolarisation droite-gauche opposant une nouvelle forme d’union des droites (bloc national-libéral RN-LR-Reconquête) et d’union des gauches (bloc social-écologique PS-PCF-LFI-EELV). On constate cependant un approfondissement du clivage territorial entre le bloc de droite et le bloc de gauche lors du scrutin européen de 2024. Sur la base de l’expérience historique du 20 e siècle, on peut considérer que le scénario de rebipolarisation gauche-droite ne pourra pleinement se réaliser que si le clivage social l’emporte beaucoup plus nettement sur le clivage territorial, ce qui exige que le bloc de gauche parvienne à reconquérir une proportion sensiblement plus importante qu’actuellement de l’électorat populaire des bourgs et des villages
The role of different types of knowledge and expertise in explaining recognition justice in flood defence and flood risk prevention
No full textInternational audienceAbstract Flood risks worldwide are rising and it is increasingly recognised that the impacts of floods are not neutral. Socioeconomic and demographic characteristics determine people's capacity to deal with flood events. These differences in social vulnerability to floods need to be considered in flood risk management (FRM) to prevent the most vulnerable groups from being disproportionately impacted. However, due to a diversification of FRM strategies and the involvement of various policy domains, the experts working on FRM are no longer a homogeneous group. Where FRM was previously dominated by engineers, now various experts are involved that have different disciplinary backgrounds, knowledge bases and approaches to FRM. As a result, they also differ in their recognition of social vulnerability to floods. In this paper, we explore the different types of knowledge and expertise in FRM in three countries (England, Flanders and France), focussing on the strategies of flood defence and flood risk prevention. We characterise the epistemic communities supporting the domains and study to what extent experts differ in their recognition of social vulnerability to floods. We also dive into the mechanisms employed to stimulate integration between experts and consider the extent to which this integration can strengthen recognition justice
Agnostic latent diversity enhancement in generative modeling
No full textGenerative modeling methods can generate images from textual or visual inputs. However, diversity in the generated images persists as a major challenge of the existing approaches. In this work, we address this issuehead-on by demonstrating that: (a) the diversity of a generated batch of images is intrinsically linked to the diversity within the latent variables; (b) leveraging the geometry of the latent space, we can establish an effectivemetric for quantifying diversity; and (c) employing this insight allows one to achieve a significantly enhanced diversity in image generation beyond the capabilities of traditional random independent sampling. This advancement is consistent across a variety of generative models, including Generative Adversarial Networks (GANs) and latent diffusion models. To facilitate further research and application in this field, we are also releasing a comprehensive package that enables easy reproduction of our experiments. We integrate our contributions into a widely recognized tool for generative image modeling, ensuring that our improvements are accessible to the broader community
Lời giới thiệu cho cuốn “Tình thương trong Kỷ Nguyên AI”
No full textInternational audienceThis foreword introduces a book on Compassion in the AI era, providing context on the author's background and previous work on Compassion. It discusses the book's visionary approach and practical proposals for integrating Compassion into AI development. The foreword reviews the current state of AI and Compassion research, highlighting recent studies on AI-generated empathy and human-AI alignment in moral decision-making. It emphasizes the urgency of embedding Compassion in AI systems and the need for benchmarking AI models on moral and emotional capabilities. The foreword concludes by praising the book's accessible writing style and its potential to inspire readers to contribute to a more compassionate future.Cette préface introduit un livre sur la Compassion à l'ère de l'IA, fournissant un contexte sur le parcours de l'auteur et ses travaux antérieurs sur la Compassion. Elle discute de l'approche visionnaire du livre et de ses propositions pratiques pour intégrer la Compassion dans le développement de l'IA. La préface examine l'état actuel de la recherche sur l'IA et la Compassion, soulignant les études récentes sur l'empathie générée par l'IA et l'alignement homme-IA dans la prise de décision morale. Elle souligne l'urgence d'intégrer la Compassion dans les systèmes d'IA et la nécessité d'évaluer les modèles d'IA sur leurs capacités morales et émotionnelles. La préface conclut en louant le style d'écriture accessible du livre et son potentiel à inspirer les lecteurs à contribuer à un avenir plus compatissant.Lời tựa này giới thiệu một cuốn sách về Lòng Trắc Ẩn trong kỷ nguyên AI, cung cấp bối cảnh về nền tảng của tác giả và công trình trước đây về Lòng Trắc Ẩn. Nó thảo luận về cách tiếp cận mang tính tầm nhìn và các đề xuất thực tế của cuốn sách để tích hợp Lòng Trắc Ẩn vào phát triển AI. Lời tựa đánh giá tình trạng hiện tại của nghiên cứu về AI và Lòng Trắc Ẩn, nhấn mạnh các nghiên cứu gần đây về sự đồng cảm do AI tạo ra và sự phù hợp giữa con người và AI trong việc ra quyết định đạo đức. Nó nhấn mạnh tính cấp thiết của việc tích hợp Lòng Trắc Ẩn vào hệ thống AI và nhu cầu đánh giá các mô hình AI về khả năng đạo đức và cảm xúc. Lời tựa kết luận bằng cách khen ngợi phong cách viết dễ tiếp cận của cuốn sách và tiềm năng truyền cảm hứng cho độc giả đóng góp vào một tương lai nhân ái hơn
Centrifuge study of a reduced model of a geothermal pile loaded horizontally
No full textInternational audienceAs part of the ANR "COOP" (Combined lOading Of energy Piles) project, the Geotechnical Centrifuge Laboratory at Gustave Eiffel University has studied the bending behaviour of a small geothermal pile, subjected to temperature cycles and horizontal head loading. It simulates a prototype pile 16 m long and 0.8 m in diameter. This study aims to predict the horizontal behaviour of reinforced concrete geothermal energy piles (GEPs) subject to lateral loads, followed by thermal loads with alternating heating and cooling cycles in saturated dense sand. The study examined three piles: a capacity pile to measure its ultimate load (Fu), a reference pile and an energy pile tested at 50% of Fu. A four-point bending test highlighted a low Young's modulus, confirming soft characteristics in the pile. Thermal loading led to significant displacement accumulation, potentially impacting both pile and soil properties. The study provided insights into failure characteristics and the impact of thermal loading on energy piles
Etude en centrifugeuse d'un pieu géothermique en ciment armé sous chargement horizontal en tête
No full textInternational audienceAs part of the ANR "COOP" (Combined lOading Of energy Piles) project, the Geotechnical Centrifuge Laboratory at Gustave Eiffel University has studied the bending behavior of a small geothermal pile, subjected to temperature cycles and horizontal head loading. The reinforced cement model pile is embedded in saturated sand. It simulates a prototype pile 16 m long and 0.8 m in diameter.Dans le cadre du projet ANR « COOP » (Combined lOading Of energy Piles), le laboratoire Centrifugeuses géotechniques de l'Université Gustave Eiffel a étudié le comportement à la flexion d'un pieu géothermique à échelle réduite, soumis à des cycles de température et à un chargement horizontal en tête. Le pieu modèle en ciment armé est fiché dans un sable saturé. Il simule un pieu prototype de 16 m de longueur et 0,8 m de diamètre
What is the relative impact of nudging and online coupling on meteorological variables, pollutant concentrations and aerosol optical properties?
No full textInternational audienceMeteorological and chemical modelling at the regional scale often involve the nudging of the modelled meteorology towards reanalysis fields and meteo-chemical coupling to properly consider the interactions between aerosols, clouds and radiation. Both types of processes can change the meteorology, but not for the same reasons and not necessarily in the same way. To assess the possible interactions between nudging and online coupling, several simulations are carried out with the WRF–CHIMERE (Weather Research and Forecasting) model in its offline and online configurations. Through comparison with measurements, we show that the use of nudging significantly improves the model performances. We also show that coupling changes the results much less than nudging. Finally, we show that when nudging is used, it limits the variability in the results due to coupling
Le développement de l'automobilité partagée dans les villes : analyse comparée des services et des politiques publiques associées à Londres, Paris, Helsinki et Moscou (1999-2019)
No full textOver the past two decades, urban transportation systems in developed countries, traditionally divided between public transit and private (motorized) transport, have seen the emergence or the development of shared mobility services. Despite their limited share in daily mobility compared to public transit and private car, shared mobility services have experienced accelerated growth and diversification since 2010. Even if some development trends of shared mobility services are seen at the international level, the configurations of urban systems, and the trajectories of services and associated regulations that lead to said configurations, differ according to local contexts. This research aims to analyse how shared mobility services develop in various urban systems and which factors influence their development. It focuses on car-based shared mobility services, such as carsharing, taxi and for-hire services, on the grounds of the growing tensions surrounding the role of the car in urban systems. Focusing on the 20-year period from 1999 to 2019, i.e. 10 years before and 10 years after the emergence of the smartphone, allows this research to shed light on the influence of digital technologies on ongoing transformations. A comparative method was designed specifically for the purposes of this research and applied to four European metropolitan areas: London in the United Kingdom, Paris in France, Helsinki in Finland and Moscow in Russia. This research is based on an extensive documentary analysis completed by 78 semi-structured interviews with representatives of public authorities and car-based mobility services and experts, in all four cities. This research highlights the boom in car-based shared mobility services that has resulted from the development of digital technologies and the acceleration of ongoing transformations, particularly in terms of hybridisation and platformisation of services. In addition, these transformations contribute to reconfigurations in the roles of stakeholders in the construction of urban mobility systems. This research sheds light on the games of (inter)dependence, cooperation, competition and opposition that characterise interactions among stakeholders. These complex and dynamic interactions operate on different scales for both categories of services: more local for carsharing services, where the involvement of stakeholders extends to the co-construction of public policies, and more regional or even national for taxi and for-hire services. Even though in all four case studies, the initial push for development comes from the mobility services, public policies undeniably set the pace for their development. Certain public policies regulating access to public space have almost immediate effects on carsharing services, as do certain deregulation policies for taxi and for-hire services. Finally, the research highlights the multidimensional nature of interactions between stakeholders, which involve a wide variety of spaces and temporalities, each of which is perceived differently by each stakeholder.Durant les deux dernières décennies, les systèmes de mobilité urbains des pays développés, construits autour de la voiture individuelle d'un côté et des transports collectifs de l'autre, ont vu l'apparition ou le développement des services de mobilité partagée. Au fils du temps, les dynamiques de croissance et de diversification de ces services semblent s'accélérer, même s'ils restent marginaux par rapport aux deux modes principaux. Bien que le développement des services de mobilité partagée fasse l'objet de tendances attestées à l'échelle internationale, les configurations des systèmes urbains, et les trajectoires des services et des régulations associées qui y conduisent, se différencient en fonction des contextes territoriaux à l'échelle locale. Cette thèse s'intéresse aux modalités selon lesquelles les services de mobilité partagée se développent dans différents systèmes de mobilité et aux facteurs qui influencent leur développement. Compte tenu des tensions de plus en plus prononcées relatives à la place de l'automobile dans les systèmes urbains, cette recherche se concentre sur les services d'automobilité partagée, tels que l'autopartage, les taxis et les VTC. La profondeur temporelle de l'analyse, portant sur vingt ans de 1999 à 2019, soit 10 ans avant et 10 ans après l'apparition du smartphone, permet de retracer l'influence des technologies numériques sur les transformations en cours. L'analyse s'appuie sur un dispositif de comparaison construit spécifiquement aux fins de cette recherche et appliqué à quatre métropoles européennes : Londres au Royaume-Uni, Paris en France, Helsinki en Finlande et Moscou en Russie. Cette recherche se base à la fois sur une analyse documentaire extensive et sur l'analyse des discours des acteurs recueillis au travers de 78 entretiens semi-directifs réalisés avec les représentants d'autorités publiques et de services d'automobilité partagée et des experts, dans les quatre métropoles. La thèse met en évidence l'essor des services d'automobilité partagée consécutif au développement des technologies numériques et l'accélération des transformations en cours, notamment en termes d'hybridation et de plateformisation des services. En plus, ces transformations participent aux reconfigurations en termes de rôles des acteurs dans la construction des systèmes de mobilité. La thèse met en lumière les jeux d'(inter)dépendance, de coopération, de concurrence et d'opposition qui caractérisent les interactions entre acteurs. Ces relations à la fois complexes et dynamiques s'inscrivent à des échelles différentes pour les deux catégories des services : plus locale pour l'autopartage, dont l'implication des acteurs va jusqu'à à la co-construction des politiques publiques, et plus large pour les services de taxi et de VTC, dont les régulations sont d'une manière générale traitées au niveau régional, voire national. Même si dans les quatre cas d'études, l'initiative de développement émane des services de mobilité partagée, les politiques publiques rythment incontestablement le développement desdits services. Certaines politiques publiques en matière d'accès à l'espace public ont des effets quasi-instantanés sur les services d'autopartage ; il en va de même de certaines politiques de dérégulation pour les taxis et VTC. Finalement, la thèse met en lumière le caractère multidimensionnel des interactions entre les acteurs, qui font intervenir une grande diversité d'espaces et de temporalités, dont chaque acteur a sa propre perception
Soil Carbon-Concentration And Carbon-Climate Feedbacks In Cmip6 Earth System Models
No full textInternational audienceAchieving climate targets requires mitigation against climate change but also understanding of the response of land and ocean carbon systems. In this context, global soil carbon stocks and their response to environmental changes are key. This paper quantifies the global soil carbon feedbacks due to changes in atmospheric CO2, and the associated climate changes, for Earth system models (ESMs) in CMIP6. A standard approach is used to calculate carbon cycle feedbacks, defined here as soil carbon-concentration (βs) and carbon-climate (γs) feedback parameters, which are also broken down into processes which drive soil carbon change. The sensitivity to CO2 is shown to dominate soil carbon changes at least up to a doubling of atmospheric CO2. However, the sensitivity of soil carbon to climate change is found to become an increasingly important source of uncertainty under higher atmospheric CO2 concentrations