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Locked in a data imperative? French local businesses faced with Google Maps
No full textInternational audienceThis article examines how Google Maps is reshaping local markets by imposing a data imperative on businesses, compelling them to continuously produce and update data to maintain their visibility and competitiveness. Using France as a case study, it conceptualizes Google Maps as an ordinal device: a ranking mechanism that classifies and orders businesses based on data-driven metrics rather than traditional market dynamics. The findings reveal how Google Maps fosters new forms of competition, where business success is increasingly determined by algorithmic valuation and digital reputation. This process transforms market hierarchies, embedding merchants into a self-reinforcing cycle of data accumulation that strengthens Google’s informational dominance. By framing data capital as a key determinant of visibility in platform-mediated markets, this article contributes to debates on digital capitalism and spatial inequalities, highlighting how platform infrastructures reorganize economic life at the local level
Mitigating Urban Heat Islands with Nature-Based Solutions: The PENATE Project in Action
No full textInternational audienceThe PENATE project seeks to assess the performance and effectiveness of Nature-Based Solutions (NbS) as a critical tool for adapting urban environments to climate change, particularly with regard to microclimate regulation and urban heat island mitigation. Through this project, we aim to develop advanced, multi-scale, multi-criteria, and context-specific evaluation frameworks that will enable local authorities to assess and optimize the deployment of NbS. In addition to microclimate mitigation, these tools will provide actionable insights into the effectiveness of NbS in addressing stormwater management and enhancing the overall quality of life while ensuring ecological continuity.The project is supported by a multidisciplinary consortium that brings together experts in microclimatology, hydrology, ecology, public policy, and law, alongside research organizations and operational entities. PENATE is built around several sites where NbS interventions are actively being monitored, offering valuable real-time data on their impact and performance. This data will be pivotal in advancing our understanding of how NbS can alleviate urban heat islands and contribute to sustainable, climate-resilient cities.Key anticipated outcomes of the project include:- Quantitative insights into NbS’ role in microclimate regulation, especially in mitigating heat islands. How different vegetation types and configurations influence thermal and hydrological processes will be explored, using a functional traits-based approach to connect plant characteristics with performance.- Digital simulation tools that will model and predict the multifunctionality of NbS, offering local authorities the ability to assess their impact across different scales—ranging from local neighborhoods to larger urban regions.- The development of decision-support tools that can directly inform urban planning processes, including regulatory and strategic frameworks like local urban development plans (PLUi), climate air energy plans (PCAET), and objectives such as Zero Net Artificialization (ZAN). These tools will help local authorities implement NbS with a focus on heat justice and urban sustainability, facilitating the integration of nature-based interventions into mainstream urban plannin
Opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) on the risks to human health associated with the proliferation of Ostreopsis spp. on the Basque coast
No full textN/AInternational audienceIn France, the presence of marine microalgae of the genus Ostreopsis has been identified repeatedly on the Mediterranean coast for several years, whereas on the French Basque coasts its presence is much more recent. In the summers of 2021 and 2022, major Ostreopsis flowering episodes were reported on the Basque coast, resulting in several hundred cases of intoxication among holidaymakers and residents. The main route of human exposure is inhalation of aerosols, although it is not yet known whether the agents responsible for poisoning are Ostreopsis cells, cell debris, known toxins produced by Ostreopsis, or other as yet unidentified compounds. Other routes of exposure (dermal contact, eye contact, ingestion of contaminated water or seafood) are also possible. Poisoning is manifested through various signs and symptoms, occurring within 48 hours of exposure (Neurosensory and neurological, respiratory, dermal and digestive). This document presents the opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), established from the work of its WATER and ERCA Expert Committees. ANSES received a request from the Directorate General for Health (DGS) and the Directorate General for Food (DGAL) to update knowledge about Ostreopsis that had been reported in the Agency's opinions from 2007 and 2008 (ANSES, 2007 and 2008), and draw up specific recommendations for managing Ostreopsis proliferation on the Basque coast. The literature review conducted as part of this expert appraisal revealed that knowledge about the genus Ostreopsis (diversity, biology, ecology, toxins produced) is still too fragmentary to characterise the hazard and risk to human health. Nevertheless to help local authorities affected by Ostreopsis blooms, Agency proposes a surveillance and quality monitoring strategy based on collaboration between site managers and the regional health agencies (ARSs), applicable to sites currently subject to bathing water quality monitoring and water sports sites that meet the conditions below
PROXQP: an Efficient and Versatile Quadratic Programming Solver for Real-Time Robotics Applications and Beyond
No full textInternational audienceConvex Quadratic programming (QP) has become a core component in the modern engineering toolkit, particularly in robotics, where QP problems are legions, ranging from real-time whole-body controllers to planning and estimation algorithms. Many of those QPs need to be solved at high frequency. Meeting timing requirements requires taking advantage of as many structural properties as possible for the problem at hand. For instance, it is generally crucial to resort to warm-starting to exploit the resemblance of consecutive control iterations. While a large range of off-the-shelf QP solvers is available, only a few are suited to exploit problem structure and warm-starting capacities adequately. In this work, we propose the PROXQP algorithm, a new and efficient QP solver that exploits QP structures by leveraging primal-dual augmented Lagrangian techniques. For convex QPs, PROXQP features a global convergence guarantee to the closest feasible QP, an essential property for safe closedloop control. We illustrate its practical performance on various standard robotic and control experiments, including a real-world closed-loop model predictive control application. While originally tailored for robotics applications, we show that PROXQP also performs at the level of state of the art on generic QP problems, making PROXQP suitable for use as an off-the-shelf solver for regular applications beyond robotics
Site Frequency Spectrum in stationary branching populations
No full textThis paper explores the Site Frequency Spectrum (SFS) in stationary branching populations. We derive estimates for the SFS associated with a sample from a continuous-state branching process conditioned to never go extinct, utilizing a quadratic branching mechanism. The genealogy of such processes is represented by a real tree with a semi-infinite branch, and we compute the expectation of the SFS under the infinitely-many-sites assumption as the sample size approaches infinity. Additionally, we present a continuum version of the SFS as a random point measure on the positive real line and compute the density of its expected measure explicitly. Finally, we derive estimates for the size of the clonal subpopulation carrying the same genotype as the most recent common ancestor of the whole population at a given time
Resolutions in a system of financially linked firms: relying on coarse information
No full textIn a financial system, firms hold debts both within and outside the system.To limit miscoordination and cascades of defaults, an orderly resolution must be conducted at the system level and simultaneously liquidate all debts. This paper analyzes such resolutions under two main assumptions. First, a default on external creditors, say on banks' customers, triggers bankruptcy and should be avoided as much as possible because of large negative externalities. Second, resolutions are coarse, as they specify the payments between each firm and its external creditors and the system without specifying the reimbursement of each bilateral liability. I present properties that determine which firms become bankrupt and how much each non-bankrupt firm reimburses to and receives from the system. The main properties rely on the priority of external creditors at the system level, which reflects the policy recommendations after the 2018 financial crisis, and the proportionality principle
Benchmarking CO2 Storage Simulations: Results from the 11th Society of Petroleum Engineers Comparative Solution Project
No full textInternational audienceThe 11th Society of Petroleum Engineers Comparative Solution Project (shortened SPE11 herein) benchmarked simulation tools for geological carbon dioxide (CO2) storage. A total of 45 groups from leading research institutions and industry across the globe signed up to participate, with 18 ultimately contributing valid results that were included in the comparative study reported here. This paper summarizes the SPE11. A comprehensive introduction and qualitative discussion of the submitted data are provided, together with an overview of online resources for accessing the full depth of data. A global metric for analyzing the relative distance between submissions is proposed and used to conduct a quantitative analysis of the submissions. This analysis attempts to statistically resolve the key aspects influencing the variability between submissions. The study shows that the major qualitative variation between the submitted results is related to thermal effects, dissolution-driven convective mixing, and resolution of facies discontinuities. Moreover, a strong dependence on grid resolution is observed across all three versions of the SPE11. However, our quantitative analysis suggests that the observed variations are predominantly influenced by factors not documented in the technical responses provided by the participants. We therefore identify that unreported variations due to human choices within the process of setting up, conducting, and reporting on the simulations underlying each SPE11 submission are at least as impactful as the computational choices reported
Behavioral, computational and self-reported measures of reward and punishment sensitivity as predictors of mental health characteristics
No full textInternational audienceComputational psychiatry proposes that behavioral task-derived computational measures can improve our understanding, diagnosis and treatment of neuropsychiatric disorders. However, recent meta-analyses in cognitive psychology suggest that behavioral and computational measures are less stable than self-reported surveys as assessed by test–retest correlations. If extended to mental health measures, this poses a challenge to the computational psychiatry agenda. To evaluate this challenge, we collected cross-sectional data from participants who performed a popular reinforcement-learning task twice (~5 months apart). Leveraging a well-validated neuro-computational framework, we compared the reliability of behavioral measures, computational parameters and psychological and mental health questionnaires. Despite the remarkable replicability of behavioral and computational measures averaged at the population level, their test–retest reliability at the individual level was surprisingly low. Furthermore, behavioral measures were essentially correlated only among themselves and generally unrelated to mental health symptoms. Overall, these findings challenge the translational potential of computational approaches for precision psychiatry
On the convergence criterion in three-period lived overlapping generations models
No full textInternational audienceThis paper offers a novel perspective on Kehoe-Levine’s convergence criterion for equilibrium determinacy in three-period overlapping generations (OLG) models. Departing from their primary focus on gross substitutability, our central contribution is demonstrating that equilibrium determinacy, even in Samuelson economies, can be achieved under market complementarities, provided the aggregate demand sensitivities to adjacent-period prices sum positively. Furthermore, we identify critical conditions where gross substitutability or complementarities between goods spaced two periods apart becomes pivotal for equilibrium determination. By elucidating the role of asymmetric complementarities, we significantly extend the understanding of equilibrium determinacy within the Kehoe-Levine framework, challenging the necessity of strict gross substitutability and offering a more nuanced view of dynamic stability in OLG models
A scoping review of the impact of agricultural, food, and environmental policies on the transition towards a safe and just operating space for EU agri-food systems
No full textInternational audienceThe transition of agri-food systems towards a safe and just operating space (SJOS) is a complex phenomenon, which implies finding proper pathways for satisfying human needs and social justice for all, while staying within the limits of the planet's natural resources. In this context, public policies can play a key role in driving the transition. Thus, in this paper, we have carried out a scoping review of the literature on the relationships between some key public policies affecting agricultural and food and the SJOS dimensions, with the purpose of identifying the most important knowledge gaps. Following the most recent protocols proposed by the literature, we have reviewed papers published in the 2000–23 period using the Web of Science database as the main reference. Our results show that the available evidence is somehow scattered across the SJOS thematic areas, with a clear prevalence of the environmental (safe operating space) with respect to the social [just operating space (JOS)] ones. Thus, there is a clear research gap in exploring the impact of public policies on JOS issues such as social equity, health, and nutrition security. Moreover, very few studies explore synergies and trade-offs between different SJOS dimensions. This is especially relevant in evaluating a complex policy mix such as the Green Deal of the European Union. Finally, from a methodological perspective, the available studies provide some interesting hints for extending the available toolkit for ex-ante policy modelling, which deserve further research