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Caractérisation des coûts cachés d'usage de pesticides par les bases de connaissances mobilisables au Cameroun
No full textFor a number of years, agriculture in Cameroon has relied heavily on the intensive use of synthetic chemical pesticides for crop protection as part of a rapid agricultural development strategy. However, in recent years, various concerns have been raised by different stakeholders (research, civil society) about the associated negative externalities affecting various dimensions of health (human, environmental, animal). These externalities can generate hidden costs. These costs are difficult to identify. To this end, the aim of this study is not to estimate these costs, but rather, as a priority, to identify the work that contextualises them and can help to identify them. To achieve these objectives, we: (i) conducted 30 interviews in three main cities (Yaoundé, Douala, Dschang) in Cameroon; (ii) analysed 31 documents (Thesis, articles, project reports, dissertations, fact sheets). The results highlight the various support measures for pesticides in Cameroon and the work carried out to identify the costs (regulatory; human health; environmental; economic) associated with pesticide use.Depuis plusieurs années, l'agriculture camerounaise repose fortement sur l'utilisation intensive de pesticides chimiques de synthèse en matière de protection de culture pour accélérer sa croissance. Cependant, depuis quelques années, diverses préoccupations ont été soulevées par différents acteurs (recherche, société civile...) quant aux externalités négatives associées touchant diverses dimensions de la santé (humaine, environnementale, animale). Ces externalités peuvent engendrer des coûts cachés. Ces derniers ont du mal à être relever. A cet effet, l'objectif de cette étude est de chercher non pas à estimer ces coûts, mais à identifier les travaux qui les contextualisent et peuvent aider à les identifier. Pour atteindre ces objectifs, nous avons : (i) réaliser 30 entretiens dans trois principales villes (Yaoundé, Douala, Dschang) du Cameroun ; (ii) analyser 31 documents (thèses, articles, rapports de projet, mémoires, Fact sheet). Les résultats identifient différents coûts : réglementaires ; santé humaine en lien avec l'usage de pesticides ; environnement ; économique ainsi que les coûts inhérents aux mesures fiscales de soutien aux pesticides
Experimental Evaluation of V2X Connectivity Technologies with V2X Channel Models
No full textInternational audienceA new concept of on-demand automatic electric vehicles able to circulate on roads and tracks is under development to revitalize secondary railway lines: the FLEXMOVE project. The operation of this new system requires a dynamic, flexible, and safe supervision system. Such a supervision system will be based on an information exchange between vehicles, level crossing, infrastructure and hubs. ITS-G5, LoRa, LTE, and 5G NR are potential wireless technologies that could be deployed to guarantee connectivity. In these conditions, it is important to evaluate the foreseen key performance indicators to support the different services. This paper presents an in-lab experimental evaluation of Vehicle-to-Everything (V2X) connectivity technologies with V2X channel models
Enforcing Colonial Rule: Blood Tax and Head Tax in French West Africa
No full textWe examine the enforcement of two pillars of colonial rule in French West Africa, military conscription and head tax collection, using novel district-level data from 1919 to 1949. Colonial states are often characterized as either omnipotent Leviathans or administration on the cheap. Our findings reveal their notable coerciveness in achieving key objectives. Military recruitment targets were consistently met, even amid individual avoidance and poor health conditions, by drawing on a pool of eligible fit young men. Tax compliance was similarly high, with approximately 80% of the liable population meeting obligations. Spikes in head tax rates significantly increased tax-related protests, likely prompting caution among colonial administrators. The tax burden was adjusted according to perceived district affluence, and tax moderation was applied in times of crisis. However, local shocks such as droughts or cash crop price collapses were largely ignored. These results underscore the capacity of colonial states to enforce their authority despite limited policy responsiveness, offering new insights into the political economy of colonial governance
La Super League : une « américanisation » du football européen ?
No full textL’idée d’un championnat regroupant les plus grands clubs européens n’est pas nouvelle. Décryptage de l’économie du soccer aux États-Unis et perspectives pour le football européen
Model-Based Approach for Efficient Data Exploitation Process in IoT Systems
No full textInternational audienceNowadays, sensor networks are used in various fields and for multiple purposes in medicine, agriculture or industry. In a network, different kinds of sensors are often involved. This heterogeneity makes it complex and time-consuming to implement the exploitation of the data acquired by these sensor networks. We notice a growing need for scalable and rapidly deployable infrastructures to allow for interoperability for the processing, the storage or visualization of collected data. Faced with these challenges, we define a framework to facilitate the automatic deployment of data exploitation applications in heterogeneous sensor networks. We propose a Model-Driven Engineering-based approach that provides a high-level model to describe such infrastructures. Along with automatic code generation, our model aims to facilitate the exploitation of collected data through a graphical interface. The model we define allows for the description of heterogeneous sensor networks with a data exploitation point of view
Agro-industry versus agroecology? Two macroeconomic scenarios for 2050 in Andhra Pradesh, India
No full textInternational audienceThis book presents the first macroeconomic scenario of a full transition to agroecology in 2050. It is for Andhra Pradesh, a state in southern India with 53 million inhabitants and 9.3 million farmers in 2020. The "Community-managed Natural Farming" scenario is compared to an industrial food and agriculture intensification scenario to assess its performance in various areas such as employment, land use, food production, economic growth or income inequality. The book also includes a unique compendium of statistics over more than half a century (from the 1960s to 2020), at three geographical scales (World, India and Andhra Pradesh), on the multiple and interconnected dimensions of agri-food systems and their structural transformation. Overall, the book is a unique presentation of the method and results of a participatory foresight exercise which combines quantitative and qualitative approaches, expertise and knowledge to help societies and their governments to better choose the future world in which they would like to live and work
Mapping out the current and ideal weekly distribution of remote work in France after COVID-19
No full textInternational audienceThe recent rise of telework brings new debates on the impacts on travel behavior and transportation systems. One key issue concerns the weekly number and distribution of remote workdays, which affects transportation networks and their congestion levels. Using data from an online survey conducted in spring 2022 in France, Bayesian regressions and a multilevel model are used to analyze employee’s current and ideal weekly number and distribution of full-day home-based remote workdays. Firstly, the findings highlight a latent demand for more remote workdays, especially among people working remotely 1 day a week. Secondly, data show a concentration of current and ideal remote workdays on Fridays, followed by Mondays and Wednesdays. Thirdly, and finally, our results show that employer’s strategies and the nature of the sector (public or private) both contribute to explain the current and ideal weekly distribution of remote workdays. These results indicate that remote work should continue to develop and be distributed unevenly over the days of the week. This uneven distribution should impact travel behavior and traffic congestion
Deliberation and the wisdom of crowds
No full textInternational audienceDoes pre-voting group deliberation improve majority outcomes? To address this question, we develop a probabilistic model of opinion formation and deliberation. Two new jury theorems, one pre-deliberation and one post-deliberation, suggest that deliberation is beneficial. Successful deliberation mitigates three voting failures: (1) overcounting widespread evidence, (2) neglecting evidential inequality, and (3) neglecting evidential complementarity. Formal results and simulations confirm this. But we identify four systematic exceptions where deliberation reduces majority competence, always by increasing Failure 1. Our analysis recommends deliberation that is ‘participatory’, ‘neutral’, but not necessarily ‘equal’, i.e., that involves substantive sharing, privileges no evidences, but might privilege some persons
Error Estimators for the Small-Biot Lumped Approximation for the Conduction Dunking Problem
No full textWe consider the dunking problem: a solid body at uniform temperature is placed in a environment characterized by farfield temperature and spatially uniform time-independent heat transfer coefficient. We permit heterogeneous material composition: spatially dependent density, specific heat, and thermal conductivity. Mathematically, the problem is described by a heat equation with Robin boundary conditions. The crucial parameter is the Biot number -- a nondimensional heat transfer (Robin) coefficient; we consider the limit of small Biot number. We introduce first-order and second-order asymptotic approximations (in Biot number) for several quantities of interest, notably the spatial domain average temperature as a function of time; the first-order approximation is simply the standard engineering `lumped' model. We then provide asymptotic error estimates for the first-order and second-order approximations for small Biot number, and also, for the first-order approximation, alternative strict bounds valid for all Biot number. Companion numerical solutions of the heat equation confirm the effectiveness of the error estimates for small Biot number. The second-order approximation and the first-order and second-order error estimates depend on several functional outputs associated to an elliptic partial differential equation; the latter is derived from Biot-sensitivity analysis of the heat equation eigenproblem in the limit of small Biot number. Most important is , the only functional output required for the first-order error estimates; admits a simple physical interpretation in terms of conduction length scale. We investigate the domain and property dependence of : most notably, we characterize spatial domains for which the standard lumped-model error criterion -- Biot number (based on volume-to-area length scale) small -- is deficient
Morse Sequences: A simple approach to discrete Morse theory
No full textInternational audienceIn this paper, we develop the notion of a Morse sequence, which provides an alternative approach to discrete Morse theory, and which is both simple and effective. A Morse sequence on a finite simplicial complex is a sequence composed solely of two elementary operations, that is, expansions (the inverse of a collapse), and fillings (the inverse of a perforation). In a dual manner, a Morse sequence may be obtained by considering only collapses and perforations. Such a sequence is another way to represent the gradient vector field of an arbitrary discrete Morse function. To each Morse sequence, we assign a reference map and an extension map. A reference map associates a set of critical simplexes to each simplex of a given complex, and an extension map associates a set of simplexes to each critical simplex. By considering the boundary of each critical simplex, we obtain a chain complex from these maps, which corresponds precisely to the Morse complex. We show that, when restricted to homology, an extension map is the inverse of a reference map. Also we show that these two maps allow us to recover directly the isomorphism theorem between the homology of an object and the homology of its Morse complex. At last, we introduce the notion of a flow complex, which is based solely on extension maps. We prove that this notion is equivalent to the classical one based on gradient flows