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From Coumarou to New-Mown-Hay. A Cultural History of Coumarin Across the Atlantic (17th-20th c.)
No full textInternational audienceFrom the late 1850s to the first years of WWI, the British, French, and American élites were seemingly obsessed with one scent – freshly mown hay – as identified by the molecule responsible for its characteristic fragrance: coumarin. In fragrance adverts, society pages, poems, and novels, the cultural omnipresence of mass-produced New-Mown-Hay fragrances is visible through a considerable rise in production of hay-scented perfumes and cosmetics across the West, but especially in France, between 1850 and 1930. From face powders and sachets to handkerchief extracts, New-Mown-Hay-scented products owe their success to the availability of two raw materials: the Tonka bean and synthetic coumarin. Originating from the forests of the Guyana Shield, the Tonka tree (Dipteryx odorata) grows in Venezuela, Suriname, Guyana, and parts of Brazil. First used in Indigenous and Creole communities for medicinal and aromatic purposes, the Tonka bean becomes a valuable commodity of transatlantic trade between France, England, Spain, Portugal, the Netherlands, and their colonies during the first half of the 19th century. It shares a common fate with more frequently studied colonial botanical commodities, such as cinchona, rubber, coffee, tobacco, or cane sugar. The success story of Tonka in 19th-century Western culture is a curious case of olfactory cultural history. The omnipresent use of Tonka in the fragrance industry for decades may not be solely due to its objective qualities as a raw material but rather to its cultural and commercial appeal as a fixture of France’s economic, political, and cultural imperialism over southern American territories. Using qualitative methods and drawing from historical, ethnobotanical, industrial, and literary sources, I hereby demonstrate how European colonial history and culture have turned a specific scent into a commodity, rather than the odorous object itself. Through a materialist consideration of olfactory history, this article examines cultural representations of the scent of new-mown hay through the aromatic raw materials used for its production to describe the processes through which a smell itself can be the subject of sensory commodification
Recommandations pour l’utilisation raisonnée des nouvelles molécules anti-VEGF
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Exploring the preferences of French university students using real-life food sourcing data: A proof-of-concept study
No full textInternational audienceTaste and preferences play a crucial role in shaping eating behaviours. However, research on the factors influencing university students' preferences in real-life settings and at the diet level remains limited. This article presents the results of a study conducted with a sample of French students who collected data on the food they personally sourced during one month alongside hedonic scores. Food preferences were compared based on food categories, sourcing locations, consumption frequencies, and the nutritional, environmental, economic, and sensory properties of the foods. The results showed that about 75 % of the sourced foods were highly appreciated, and preferred foods were generally but not systematically consumed more frequently. However, students' diet also included 25 % of moderately liked foods, such as utilitarian and routine foods. Students' preferences often conflicted with higher nutritional quality but not with lower environmental impact. Among the factors influencing preferences, foods with sweet and fatty tastes and ready-to-eat foods were generally preferred, while foods requiring culinary preparation and lower-priced foods within a category were less liked. The context in which food was sourced proved to be the most influential factor, with foods served in collective catering settings being the least liked. Certain food categories, such as fruits, emerged as offering both sensory enjoyment and potential health and sustainability benefits. This research underscores the relationships between food choices, sensory perceptions, preferences, and the context in which foods are sourced and consumed. From a methodological standpoint, it highlights the potential of real-life data collection in better understanding food consumption behaviours in relation to preferences and emphasizes the need to continue developing large-scale, ecological approaches that integrate sensory experiences within a broader context
Optimal Control of Electric Vehicles in Dynamic Wireless Charging Lanes Using Deep Q-Networks
No full textInternational audienceThe increasing adoption of electric vehicles (EVs) presents new challenges in optimizing energy consumption, charging efficiency, and travel time. Dynamic Wireless Charging Lanes (DWCLs) offer a promising solution by allowing EVs to charge while driving, reducing dependency on static charging stations and minimizing downtime. However, optimizing the decision-making process for when and at what speed a vehicle should enter and exit a DWCL while maintaining an efficient driving strategy remains a complex problem. This work proposes a Deep Q-Network (DQN)-based reinforcement learning (RL) approach to dynamically control lane-switching and speed adjustments in a multi-lane road environment. The RL agent is designed to balance energy efficiency, travel time minimization, and charging maximization, while also considering real-world constraints such as road topology, accurate energy consumption modeling, and vehicle alignment with charging coils. By leveraging CARLA as a high-fidelity simulation environment, we implement and train a policy that autonomously decides lane-switching, speed adaptation, and charging strategies. The proposed framework not only improves the charging efficiency of EVs but also ensures smooth lane transitions while maintaining energy-optimal driving behavior. Experimental results show that the RL agent effectively learns the optimal use of DWCL, minimizing unnecessary lane switches and ensuring a highly efficient, and real-time deployable EV management system
Tax revenue instability in Sub‐Saharan Africa: Does institutional quality matter?
No full textInternational audienceSub‐Saharan African (SSA) nations face a dual fiscal challenge: the need to increase tax revenue mobilization and to manage revenue instability. This paper examines the causal impact of institutional quality on tax revenue stability in SSA from 2000 to 2020. Using UNU‐WIDER data and the System GMM technique, the study finds that institutional quality reduces tax revenue instability, with a stronger effect on indirect tax revenues than on direct taxes. This result is robust to changes in the measure of tax revenue instability, the measure of quality of institutions, the sample, and the time horizon. The effect is particularly pronounced in resource‐rich countries and in countries experiencing economic growth. The article's results are relevant to tax policy, specifically the necessary adjustments to improve tax revenue stability through institutional quality
A la croisée des chemins : Etude des jugements sociaux des célébrités et des influenceurs en tant qu'endosseurs de marque
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Wave turbulence, thermalization and multimode locking in optical fibers
No full textsubmitted to Physica DInternational audienceWe present a comprehensive overview of recent advances in theory and experiments on complex light propagation phenomena in nonlinear multimode fibers. On the basis of the wave turbulence theory, we derive kinetic equations describing the out-of-equilibrium process of optical thermalization toward the Rayleigh-Jeans (RJ) equilibrium distribution. Our theory is applied to explain the effect of beam self-cleaning (BSC) in graded-index (GRIN) fibers, whereby a speckled beam transforms into a bell-shaped beam at the fiber output as the input peak power grows larger. Although the output beam is typically dominated by the fundamental mode of the fiber, higher-order modes (HOMs) cannot be fully depleted, as described by the turbulence cascades associated to the conserved quantities. We theoretically explore the role of random refractive index fluctuations along the fiber core, and show how these imperfections may turn out to assist the observation of BSC in a practical experimental setting. This conclusion is supported by the derivation of wave turbulence kinetic equations that account for the presence of a time-dependent disorder (random mode coupling). The kinetic theory reveals that a weak disorder accelerates the rate of RJ thermalization and beam cleaning condensation. On the other hand, although strong disorder is expected to suppress wave condensation, the kinetic equation reveals that an out-of-equilibrium process of condensation and RJ thermalization can occur in a regime where disorder predominates over nonlinearity. In general, the kinetic equations are validated by numerical simulations of the generalized nonlinear Schrodinger equation. We outline a series of recent experiments, which permit to confirm the statistical mechanics approach for describing beam propagation and thermalization. For example, we highlight the demonstration of entropy growth, and point out that there are inherent limits to peak-power scaling in multimode fiber lasers. We conclude by pointing out the experimental observation that BSC is accompanied by an effect of modal phase-locking. From the one hand this explains the observed preservation of the spatial coherence of the beam, but also it points to the need of extending current descriptions in future research
Explorer la complexité des langues d'Arnold dans un laser fibré à solitons à respiration
No full textNational audienceLa synchronisation est un phénomène omniprésent dans la nature et la science, et sous-tend diverses applications, telles que les télécommunications, la navigation et la médecine [1]. Les régions de synchronisation s'élargissent généralement de manière monotone avec la force du forçage, présentant ainsi une forme de langue dans l'espace des paramètres, connue sous le nom de langue d'Arnold. Une telle forme est universelle, prévalant dans de nombreux systèmes synchronisés allant de la biologie aux oscillateurs nanomécaniques et aux résonateurs Kerr. Il est intéressant de noter que des études théoriques suggèrent que sous un fort forçage externe, la forme des régions de synchronisation peut changer considérablement et des trous peuvent même émerger dans les motifs pleins [2].Cependant, l'accès expérimental à ces régimes anormaux est assez difficile, principalement parce que de nombreux systèmes expérimentaux affichant une synchronisation deviennent fragiles sous un fort forçage. Ici, nous sommes en mesure d'observer ces régimes intrigants dans un seul oscillateur – un laser à fibre fonctionnant dans le régime de soliton à respiration [3]. Plus précisément, deux types de régions de synchronisation anormales sont dévoilés, à savoir une forme en forme de feuille et une forme en forme de rayon. Le contrôle à haute résolution de la perte intracavité permet de mettre en évidence les trous dans les régions de synchronisation. Des simulations numériques basées sur un modèle laser discret confirment l'ensemble des observations expérimentales. Notre travail ouvre la possibilité de révéler la dynamique intrigante de la synchronisation et du chaos des systèmes non linéaires en utilisant un simple laser à soliton à respiration comme banc d'essai.[1] A. Pikovsky et al, Synchronization: A Universal Concept in Nonlinear Sciences, Cambridge U. Press, New York, 2001.[2] G. V. Papaioannou et al, Evidence of holes in the Arnold tongues of flow past two oscillating cylinders. Phys. Rev. Lett. 96, 014501 (2006)[3] X. Wu et al. Unveiling the complexity of Arnold's tongues in a breathing-soliton laser. Science Advances , 2025, 11, pp.eads3660
Exploring the role of identity, the other and negative attributions in conflict about biodiversity valuation
No full textInternational audienceAbstract Negotiating the many, often conflicting, values of biodiversity held by different stakeholders is a key endeavour in terms of integrating values into policy, co‐producing sustainable knowledge and achieving sustainable solutions. This negotiation is affected by stakeholders' agonistic identification processes, in which they express negative attributions linked to the other groups in relation to nature. Negative attributions are an incremental part of identification processes and stabilise and defend the own nature‐related identity through devaluing other groups relations to nature. Although they might negatively affect deliberative processes, they are currently barely recognised in value integration research. To address this gap, we carried out interviews with experts in the context of the conflict between insect conservation and conventional agriculture in Germany. We based our study in agonistic theory and analysed interviews using qualitative content analysis with a focus on how interviewees expressed negative attributions towards other parties. We focused on articulations of the utilization and wardship human–nature relational models. These cognitive models shape actors' interaction with nature as identity components and contribute to conflict as actors prioritize them differently. We found that experts expressed negative attributions with each model. We highlight the five most salient ones for each model. These attributions found in the data, as for example ‘picture book nature’, ‘business strategy’ or ‘economic priority’, and ‘alienation’, as well as their relationship to the positive identity of the respective groups are explained. While negative attributions can have negative effects on deliberative processes, such processes can be adapted to increase their robustness against a reactivation of negative attributions in value integration processes. Read the free Plain Language Summary for this article on the Journal blog
BRC4Env, the French Biological Resource Centre for Environment
No full textInternational audienceBRC4Env is the environmental pillar of the French Research Infrastructure RARe. (https://www.agrobrc-rare.org/), led by the French National Institute for Agriculture, Food and Environment (INRAE). BRC4Env manages various biological and genomic resources for agroecological research and environmental health.Since 2018, France has been engaged in the world challenge of Global Soil to preserve soil fertility. BRC4Env network includes the European Soil Conservatory, used to monitor soil health, from microbiome to pollutants. BRC4Env aims also at monitoring biodiversity in the aquatic ecosystem, holding 460.000 ichthyological samples collected for 50 years and, the terrestrial ecosystem with one million arthropod specimens collected worldwide for over a century. BRC4Env manage also living collections of parasitoid Trichogramma and arbuscular mycorrhizal fungi used in biocontrol and as biofertilizers, respectively.The catalogue of BRC4Env resources is accessible at the portal https://urgi.versailles.inrae.fr/brc4env/ and corresponding data (genomic, phenotypic, ...) are available for academic and socio-economic researchers. BRC4Env-linked publications are accessible at https://hal.inrae.fr/BRC4ENV.BRC4Env aims to provide a strategic delivery for academic and applied research in environmental health, support the agroecological transition and unravel mechanisms at stake in the adaption of species to climate and environmental changes such as pollution, emergence of pathogens or resistance