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Loneliness during the COVID-19 pandemic: Evidence from five European countries
No full textInternational audienceWe use quarterly panel data from the COME-HERE survey covering five European countries to analyse three facets of the experience of loneliness during the COVID-19 pandemic. First, in terms of prevalence, loneliness peaked in April 2020, followed by a U-shape pattern in the rest of 2020, and then remained relatively stable throughout 2021 and 2022. We then establish the individual determinants of loneliness and compare them to those found in the literature predating the COVID-19 pandemic. As in previous work, women are lonelier, and partnership, education, income, and employment protect against loneliness. However, the pandemic substantially shifted the age profile: it is now the youngest who are the loneliest. We last show that pandemic policies affected loneliness, which rose with containment policies but fell with government economic support. Conversely, the intensity of the pandemic itself, via the number of recent COVID-19 deaths, had only a minor impact. The experience of the pandemic has thus shown that public policy can influence societal loneliness trends
Retinal blood vessel segmentation from high resolution fundus image using deep learning architecture
No full textInternational audienceThe Retinal Vascular Tree (RVT) segmentation is required to diagnose various ocular pathologies. Recently, fundus images are acquired with higher resolution, which allows representing a large range of vessel thickness. However, standard Deep Learning (DL) architectures with static and small convolution size have failed to achieve higher segmentation performance. In this paper, we propose a novel DL architecture for RVT segmentation dedicated for high resolution fundus images. The idea consists at extending the U-net architecture by increasing (e.g. decreasing) convolution kernel size through convolution blocs, in correlation with downscale (e.g. upscale) of feature map dimensions. The proposed architecture is validated on HRF database, where average sensitivity is increased from 56% to 84%
Everyday Econometricians: Selection Neglect and Overoptimism When Learning from Others
No full textInternational audienceThis study explores selection neglect in an experimental investment game where individuals can learn from others’ outcomes. Experiment 1 examines aggregate-level equilibrium behavior. We find strong evidence of selection neglect and corroborate several comparative static predictions of Jehiel’s (2018) model, showing that the severity of the bias is aggravated by the sophistication of other individuals and moderated when information is more correlated across individuals. Experiment 2 focuses on individual decision-making, isolating the influence of beliefs from possible confounding factors. This allows us to classify individuals according to their degree of naïvety and explore the limits of, and potential remedies for, selection neglect
Qu’apprendre de l’histoire de Superphénix ? L’actualité d’une recherche historique
No full textInternational audienceTensions over energy supply in 2022 have sparked renewed interest in “fast-breeder” nuclear reactors. This technology, which is linked to a promise of producing abundant energy, has been the subject of passionate debate since the end of the Second World War. However, the way its story is told influences our vision of the future. This article analyzes the development of fast breeder reactors, in particular the Superphénix prototype in France, and examines how the humanities and social sciences can shed light on the stakes involved in this controversial technology.Avec les tensions sur l’approvisionnement énergétique en 2022, les réacteurs nucléaires dits « surgénérateurs » font l'objet d'un regain d'intérêt. Depuis l'après-guerre, cette technologie qui promet de produire de l’énergie en abondance suscite des débats passionnés. Cependant, la manière dont son histoire est racontée influence notre vision du futur. À travers une analyse des développements des réacteurs à neutrons rapides, notamment le prototype Superphénix en France, cet article examine comment les sciences humaines et sociales peuvent éclairer les enjeux liés à cette technologie controversée
Consensus and Disagreement: Information Aggregation under (Not So) Naive Learning
No full textInternational audienceWe explore a model of non-Bayesian information aggregation in networks. Agents noncooperatively choose among Friedkin-Johnsen-type aggregation rules to maximize payoffs. The DeGroot rule is chosen in equilibrium if and only if there is noiseless information transmission, leading to consensus. With noisy transmission, while some disagreement is inevitable, the optimal choice of rule amplifies the disagreement: even with little noise, individuals place substantial weight on their own initial opinion in every period, exacerbating the disagreement. We use this framework to think about equilibrium versus socially efficient choice of rules and its connection to polarization of opinions across groups
The Appropriation of State Secularism by Catholics
No full textWe investigate the long-run evolution of Catholics' view on State secularism in France. We explore the roots of the opposition of Catholics to secularism that can be traced back as far as the 1789 French Revolution. We provide evidence that the divide between Catholics and supporters of secularism persisted throughout the 19 th and early 20 th Centuries, affecting votes on the major secularization Laws during the Third Republic. We argue that the dual French educational system, partitioned into Catholic and secular schools, may have contributed to this persistence. We then show that Catholics eventually became supporters of secularism in France, closing the political divide on the issue. However, this shift in opinion can be explained by Catholics viewing secularism as a way of limiting the influence of Islam. We argue that views about the involvement of Muslim/Catholic authorities in public debate are significant determinants of political supply in France. Last, we show that Catholics, who now support secularism, continue to exhibit different voting behavior and attitudes than Atheists (regarding women's rights and same-sex legislation)
Air Quality Modeling Intercomparison And Multiscale Ensemble Chain For Latin America
No full textInternational audienceA multiscale modeling ensemble chain has been assembled as a first step towards an air quality analysis and forecasting (AQF) system for Latin America. Two global and three regional models were tested and compared in retrospective mode over a shared domain (120–28° W, 60° S–30° N) for the months of January and July 2015. The objective of this experiment was to understand their performance and characterize their errors. Observations from local air quality monitoring networks in Colombia, Chile, Brazil, Mexico, Ecuador and Peru were used for model evaluation. The models generally agreed with observations in large cities such as Mexico City and São Paulo, whereas representing smaller urban areas, such as Bogotá and Santiago, was more challenging. For instance, in Santiago during wintertime, the simulations showed large discrepancies with observations. No single model demonstrated superior performance over others or among pollutants and sites available. In general, ozone and NO2 exhibited the lowest bias and errors, especially in São Paulo and Mexico City. For SO2, the bias and error were close to 200 %, except for Bogotá. The ensemble, created from the median value of all models, was evaluated as well. In some cases, the ensemble outperformed the individual models and mitigated extreme over- or underestimation. However, more research is needed before concluding that the ensemble is the path for an AQF system in Latin America. This study identified certain limitations in the models and global emission inventories, which should be addressed with the involvement and experience of local researchers
Nutriments dans les eaux usées : premier bilan national détaillé d’une déperdition de ressources stratégiques
No full textInternational audienceAu sein des filières de traitement des eaux usées utilisant le procédé conventionnel à boues activées, les propriétés de décantation des boues au sein du clarificateur secondaire sont susceptibles d’être dégradées, notamment lors de phénomènes de prolifération de bactéries filamenteuses. Cette étude vise à caractériser la décantation de boues obtenues suite à la mise en place à pleine échelle d’une extraction sélective utilisant un hydro-cyclone. Les boues densifiées obtenues présentent des indices de boues stables en deçà de 50 mL.g-1 MES, y compris en période hivernale où l’indice des boues conventionnelles monte à près de 200 mL.g-1 MES. La caractérisation de la sédimentation en colonne fermée équipée de transducteurs ultrasonores a permis de caractériser les régimes de sédimentation de zone et de compression. La boue densifiée présente des vitesses de sédimentation plus que doublées par rapport à la boue conventionnelle (3 m.h-1 à 6,85 g.L-1). Le régime de compression est atteint pour la boue densifiée à une concentration critique beaucoup plus élevée (> 7 g.L-1 contre 4 g.L-1). Ainsi, la capacité d’épaississement de la boue densifiée est bien supérieure, la concentration au fond de la colonne atteignant 20,9 contre 8,5 g.L-1 respectivement pour la boue densifiée et la boue conventionnelle. Ces propriétés permettent une optimisation de la conception et du fonctionnement des ouvrages (réduction du taux de recirculation, augmentation de la charge hydraulique)
The Conundrum Challenges for Research Software in Open Science
No full textInternational audienceIn the context of Open Science, the importance of Borgman’s conundrum challenges that have been initially formulated concerning the difficulties to share Research Data is well known: which Research Data might be shared, by whom, with whom, under what conditions, why, and to what effects. We have recently reviewed the concepts of Research Software and Research Data, concluding with new formulations for their definitions, and proposing answers to these conundrum challenges for Research Data. In the present work we extend the consideration of the Borgman’s conundrum challenges to Research Software, providing answers to these questions in this new context. Moreover, we complete the initial list of questions/answers, by asking how and where the Research Software may be shared. Our approach begins by recalling the main issues involved in the Research Software definition, and its production context in the research environment, from the Open Science perspective. Then we address the conundrum challenges for Research Software by exploring the potential similarities and differences regarding our answers for these questions in the case of Research Data. We conclude emphasizing the usefulness of the followed methodology, exploiting the parallelism between Research Software and Research Data in the Open Science environment. </div
House prices and rents: a reappraisal
No full textInternational audienceIn this work, we introduce rental markets in a general equilibrium model with borrowing constraints and infinitely lived agents. We estimate our model using standard Bayesian methods and match US data on recent decades. We highlight a crucial relationship that strongly links interest rates, house prices, and rents. It represents agents’ arbitrage when choosing their degree of participation in the housing market (i.e. their real estate holdings). This framework is particularly well suited for explaining how policy-induced changes in households’ preferences have driven house prices up while pushing rent-price ratios down in the aftermath of the Covid-19 outbreak. It also allows us to parsimoniously track the unequal impact of these changes on agents’ decisions and welfare, which crucially depends on whether they are owners or renters