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Despite substantial policy efforts made by the French government to reduce dependence on pesticides, farming practices are only changing slowly. This paper analyses the socio-economic trade-offs that 110 farmers are currently facing in the transition to agro-ecological practices. A mixed-method approach - a quantitative discrete choice experiment (DCE) and qualitative interviews - was set up to understand these farmers' motivations and perspectives, and how policy can improve to accompany them on the road to low chemical input farming. Results of the DCE indicate that the majority of the farmers in our sample are keen to change practices but are at a loss as to how this can be done, as a number of preferences for this transition came out as inconclusive. Qualitative interviews with a representative sample of the farmers that took part in the DCE complemented this result by illustrating a deep uncertainty for the future and a disconnect felt between authorities and themselves as a group. We argue that this uncertainty contributed to a lack of clear-cut solutions established through the DCE. The indepth discussions with farmers illustrated the wish for concrete and local policy measures based on farmers' networks and peer support.

International audience; If individuals have spatially dierentiated preferences for sites or areas im- 8 pacted by an invasive alien species, eective management must take this 9 heterogeneity into account and target sites or areas accordingly. In this 10 paper, we estimate spatially dierentiated preferences for the management 11 of primrose willow (Ludwigia grandiora), an invasive weed spreading in a 12 French regional park. We use an original spatially explicit discrete choice 13 experiment to evaluate individuals' willingness to pay (WTP) to control the 14 invasion in dierent areas of the regional park. Our results indicate that 15 WTP for management highly depends on the area considered, with areas 16 where it is three times higher than others. We analyze the main factors 17 explaining the heterogeneity of preferences and show that the closer respo n-18 dents live to the park, the more they visit and/or practice activities in it, the 19 higher their WTP and spatial preferences. Park residents and regular users 20 have highWTP and unambiguous preferences for targeting control to specic 21 areas. Non-residents and occasional users have much lower WTP and more 22 homogeneous spatial preferences. These results suggest that implementing 23 management strategies that spatially target invasion control according to 24 public preferences is likely to produce signicant utility gains. These gains 25 are all the more important as the preferences taken into account are those of the stakeholders directly concerned by the invasion, the residents and reg-27 ular park users. Ignoring these spatial preferences will lead to sub-optimal 28 invasion management.; Lorsque les individus ont des préférences spatialement différenciée sur les sites impactés par une espèce invasive, les décideurs doivent prendre en compte cette hétérogénéité spatiale et cibler la préservation en conséquence. Nous estimons ici les préférences, de manière spatialement différenciée, pour la lutte contre la Jussie (Ludwigia grandiflora), une plante envahissante qui se développent dans un parc naturel régional français. Nous utilisons un discrete choice experiment spatialement explicite pour mesurer les consentements à payer des populations pour préserver différentes zones du parc. Nos résultats indiquent que les consentements à payer sont significativement dépendant de la zone considérée, avec certaines zones où ceux-ci sont trois fois plus élevés que dans d’autres. Nous analysons les principaux facteurs qui expliquent cette hétérogénéité spatiale des préférences et montrons que les répondants habitant proche du parc et/ou visitant souvent le parc et/ou pratiquant des activités dans le parc ont une hétérogénéité spatiale plus marquée de leurs consentements à payer.

Despite reducing the use of pesticides being a major challenge in developed countries, dedicated agri-environmental policies have not yet proven successful in doing so. We analyze conventional farmers' willingness to reduce their use of synthetic pesticides. To do so, we conduct a discrete choice experiment that includes the risk of large production losses due to pests. Our results indicate that this risk strongly limits farmers' willingness to change their practices, regardless of the consequences on average profit. Furthermore, the administrative burden has a significant effect on farmers' decisions. Reducing the negative health and environmental impacts of pesticides is a significant motivator only when respondents believe that pesticides affect the environment. Farmers who earn revenue from outside their farms and/or believe that yields can be maintained while reducing the use of pesticides are significantly more willing to adopt low-pesticide practices. Policy recommendations are derived from our results.; La réduction de l’usage de produits phytosanitaires est devenu un défi majeur en France et dans la plupart des pays développés. L’essor récent du Bio en France (+20% de ventes en 2016, BioBaromètre 2017) montre une réelle prise de conscience du grand public et de nouvelles exigences des consommateurs. Plusieurs pratiques permettant de réduire le recours aux produits phytosanitaires tout en maintenant les profits semblent avoir émergé dans des réseaux pilotes (Lerchenet et al 2017) mais demeurent peu appliquées par la majorité des agriculteurs. Les politiques publiques mises en place jusqu’à présent ont abouti à des résultats décevants et l’utilisation de produits phytosanitaires continue d’augmenter (hausse d’environ 12% en France entre 2009 et 2014). Notre étude s’interroge sur les principaux freins et principales motivations des agriculteurs français à réduire leur utilisation de pesticides. Elle repose sur la méthode d'expérimentation par les choix (Discrete Choice Experiment) et permet de mesurer le poids relatif de différents facteurs de décision dans les choix de pratiques des agriculteurs. Elle permet également d’estimer des consentements et payer / à recevoir pour les éléments non monétaires associés à ces choix de pratiques agricoles. Nous montrons notamment que le rôle du risque-récolte est prépondérant dans la réticence des agriculteurs à réduire leur usage de produits phytosanitaires.

Submitted by Maria Antonia de Sousa (mariaantoniade.sousa@gmail.com) on 2019-01-22T09:42:32Z No. of bitstreams: 1 DAVID CANDEIA MEDEIROS MAIA - TESE PPGCC.pdf: 15054701 bytes, checksum: ab07062878cff73c5f73896b828daaf8 (MD5) Made available in DSpace on 2019-01-22T09:42:32Z (GMT). No. of bitstreams: 1 DAVID CANDEIA MEDEIROS MAIA - TESE PPGCC.pdf: 15054701 bytes, checksum: ab07062878cff73c5f73896b828daaf8 (MD5) Previous issue date: 2018-09-06 Capes O conceito de percepção urbana pode ser visto como o entendimento, o significado que as pessoas atribuem a seus espaços urbanos. Estas percepções têm uma grande importância uma vez que as pessoas guiam suas ações no espaço a partir delas. Por isto, vários estudos têm sido conduzidos ao longo dos anos buscando entender melhor esta relação entre as pessoas e os espaços urbanos para, assim, produzir conhecimento que possa ser utilizado na melhoria dos projetos e ações de gestão dos espaços. Os métodos tradicionais que eram utilizados na condução destes estudos envolviam visitas aos locais, entrevistas e a utilização de questionários, que podiam ou não apresentar imagens dos espaços avaliados. O avanço da computação tem trazido soluções e métodos que podem contribuir com uma maior agilidade na captura de dados, reduzindo custos e ampliando a quantidade de participantes nas pesquisas. Crowdsourcing é uma destas soluções. Neste contexto, esta tese investigou o uso de crowdsourcing para condução de análises de percepção focando tanto em uma escala maior, considerando cenas urbanas de vários pontos da cidade, como em uma escala menor, considerando uma maior quantidade de cenas para locais específicos da cidade. Duas etapas de coleta de cenas e percepções foram realizadas, tendo como foco a cidade de Campina Grande, Paraíba. Em um primeiro estudo, focando em uma escala maior, foi avaliado um método para relacionar as percepções capturadas com características do espaço urbano e com o perfil sociodemográfico dos participantes da pesquisa. Os resultados obtidos demonstraram, por exemplo, que os participantes avaliaram as cenas com mais árvores e que apresentavam um melhor estado de manutenção como mais agradáveis, e as cenas que apresentavam um melhor estado de manutenção e possuíam mais pessoas como mais seguras. Além disso, foi possível encontrar algumas diferenças de percepção entre grupos de participantes e relacionar estas diferenças com características do espaço. Por exemplo, homens e pessoas de mais alta renda preferiram ainda mais espaços bem mantidos do que mulheres e pessoas de baixa renda. Em um segundo estudo, focando uma escala menor, foi avaliada a utilização do método de cálculo de surpresas de Bayes para encontrar cenas na rua que se destacam em relação a sua vizinhança. Os resultados obtidos demonstraram que dentre as cenas destacadas pelo método foi possível encontrar cenas com virtudes e problemas técnicos, apontados por urbanistas, bem como foi possível reconhecer cenas relevantes e acionáveis junto a equipes de gestão tanto do ponto de vista dos participantes da pesquisa como do ponto de vista de usuários da rua. Urban perception concept can be seen as the understanding, the meaning that people give to their urban spaces. Such perception are of great importance since people guide their actions in space according to how they perceive the spaces around them. For this reason, several studies have been performed over the years seeking to better understand this relationship between people and urban spaces in order to produce knowledge that can be used to improve urban projects and space management. Traditional methods used by such studies involved site visits, interviews and the use of questionnaires, which could present or not images of the spaces being evaluated. Computing advancement has brought solutions and methods that can contribute to greater agility in data capture, reducing costs and increasing the number of participants in the research. Crowdsourcing is one of these solutions. In this context, this thesis investigated the use of crowdsourcing to conduct urban perception studies focusing both on a larger scale, considering urban scenes from several points of the city, as well as on a smaller scale, considering a larger number of scenes for specific sites in the city. Two major steps of urban scenes and perception collection were performed, focusing on the city of Campina Grande, Paraíba. In a first study, which focus on a larger scale, we evaluated a method to relate gathered perceptions, urban space characteristics and sociodemographic profile of participants. The results showed, for example, that participants evaluated the scenes with more trees and better maintenance condition of their elements as more pleasant, and the scenes that had better maintenance condition of their elements and more people as safer. In addition, it was possible to find some perception differences between groups of participants and relate these differences with urban space characteristics. For example, men and high income people have preferred even more well-maintained places than women and low income people. In a second study, which focus on a smaller scale, we evaluated the use of a method that calculates Bayesian surprises to find urban scenes that stand out from their neighborhood. The results showed that among scenes highlighted by the method it was possible to find scenes with technical virtues and problems, pointed out by urbanists, as well as it was possible to recognize relevant and actionable scenes, towards management teams, from the point of view of research participants and street users.

International audience; The conciliation between different issues such as production activities, biodiversity conservation and water management remains unsolved in many places in the world. As a striking example, the wet grasslands of the Marais Poitevin region (France) present many obstacles against the integration of previous issues, especially in terms of public policy design. The socio-cultural situation in this region shows a high degree of political resistance and questions the relevancy of the current Agri-Environmental Schemes (AES) as an incentive for livestock farmers to adopt biodiversity friendly practices favoring the birds’ richness of the area. Yet, the current AES based on financial support has been interpreted has a production support and has still not fulfilled its goal of agro-ecology development. The reasons of the poor effect of public policy are studied using a two-fold approach based on ethnographic field and a computer-assisted role-playing game. The game combines an agent-based model and a tabletop artifact. The game is based on two sessions involving different AES to be tested. The model simulates the grass regeneration and flows of water through a canal system and a surrounding network of plots with culture (wheat, corn, sunflower, alfaalfa), pasture and mowing. The game is played by 9 players who embody their role in real life, i.e. water managers, biodiversity managers and 7 farmers. The behaviors of the players during the sessions have been observed and analyzed through a miro economic conceptualization. A comparison is proposed between the first session where the current AES were tested and the second session where collective public policy instruments were tested. Such comparison identifies individual and collective level on an economic perspective and brings new concerns for public policy design. It also highlights the topic of integrated environmental management and questions the relevancy of participatory approaches and contradiction/dilemmas resolutions in environmental development.

Initially used as a biological control against aphids, the Asian ladybird has become highly invasive in many regions, including Europe. While biological control is usually considered as an environmentally-friendly alternative to chemical pesticides in controlling pests in crops, there is growing concern that these environmental benefits could be outweighed by the negative consequences of the invasion. These include (i) biodiversity losses as populations of native ladybirds suffer from intraguild predation and competition for resources; (ii) human nuisance in houses, including risks of allergy and (iii) potential losses to wine-growers. We provide an economic valuation of environmental and private characteristics affected by the Asian ladybird's invasion. We conduct a discrete choice experiment among a representative sample of the French population. Our results show that the consequences of the Asian ladybird's introduction do affect significantly the population's welfare. Among these, the impact on biodiversity through the threat on native species appears to be a significant concern., Pour cet article, les auteurs ont mené une évaluation monétaire des impacts de la coccinelle asiatique. Cette coccinelle, devenue envahissante, est un agent de lutte biologique introduit dans de nombreuses régions dans le monde, y compris en Europe. Alors que le contrôle biologique est généralement considéré comme une alternative écologique aux pesticides, pour lutter contre les ravageurs des cultures, les conséquences négatives de l'invasion pourraient dépasser les bénéfices environnementaux. Il s'agit notamment (i) des pertes de biodiversité des populations de coccinelles indigènes qui souffrent de la prédation et de la concurrence sur les ressources ; (ii) des nuisances humaines dans les maisons, y compris les risques d’allergies et (iii) des pertes potentielles des viticulteurs en termes qualité du vin. Le but de cet article est d’évaluer ces caractéristiques environnementales et privées concernées par l’introduction de la coccinelle asiatique. Les auteurs ont mené une choice experiment auprès d’un échantillon représentatif de la population française. Nos résultats montrent que les conséquences de l’introduction de la coccinelle asiatique affectent significativement l’utilité de la population. Parmi celles-ci, l’impact sur la biodiversité à travers la menace des coccinelles indigènes semble être une préoccupation importante, avec un consentement à payer non négligeable pour éviter leur disparition.

Backgroud: Port-a-Cath catheters have been widely used in the clinical systemic therapy of cancer owing to the level of safety and effectiveness provided to patients during the treatment. The current study aimed to evaluate the decrease in risk of infection and the permeability condition of totally implanted catheters by using distilled water in the maintenance of Port-a-Caths. Methods and findings: Over the period between November 2008 and October 2014, a total of 109 patients with Port-a-Cath were attended to at the Ambulatory Chemotherapy Treatment Center from the Santa Marcelina Hospital in Sao Paulo, Brazil. The focus was on patients who had the totally implanted catheters, encompassing not only the treatment itself but also the maintenance of the devices. From the total sample, only 5 patients (4.6%) had catheter infection. Statistical analysis was performed using STATA 11.0. Conclusion: The conclusion was that the use of distilled water in the maintenance of a Port-a-Cath has proven to be effective and safe regarding infection risks and the device permeability.

Voluntary Agreements as an Environmental Policy Instrument For the past ten years, polluting firms have increasingly adopted a pro-active attitude towards the environmental protection. These environmental initiatives from polluters are called « voluntary approaches ». Their increasing implementation raises some questioning on their ability to protect the environment in an efficient way. May the regulator rely on firms to contribute to sustainable development in a credible and responsible way ? Under which conditions can voluntary approaches replace or complete the traditional environmental policy tools ? This article surveys the existing academic literature on voluntary approaches and offers some suggestions for further research in this field., Maia David Les approches volontaires comme instrument de régulation environnementale Depuis une dizaine d'années, les grandes entreprises polluantes ont été de plus en plus nombreuses à adopter une attitude active face à la protection de l'environnement. Ces initiatives des industriels en matière d'environnement ont pris le nom d'« approches volontaires ». Le recours croissant à ce type d'approche suscite des interrogations quant à leur aptitude à protéger l'environnement de manière efficace. Peut-on compter sur les entreprises pour contribuer au développement durable de manière crédible et responsable ? Dans quelle mesure, et sous quelles conditions, les approches volontaires peuvent-elles remplacer ou compléter les instruments traditionnels de régulation environnementale ? Cet article propose une analyse critique de la littérature académique sur les approches volontaires et une réflexion sur les pistes de recherche pertinentes pour la compléter., David Maia. Les approches volontaires comme instrument de régulation environnementale. In: Revue française d'économie, volume 19, n°1, 2004. pp. 227-273.

The aim of this paper is to compare different environmental policies for cost-effective habitat conservation on agricultural lands, when the desired spatial pattern of reserves is a random mosaic. We use a spatially explicit mathematical programming model which studies the farmers' behavior as profit maximizers under technical and administrative constraints. Facing different policy measures, each farmer chooses the land-use on each field, which determines the landscape at the regional level. A spatial pattern index (Ripley L function) is then associated to the obtained landscape, indicating on the degree of dispersion of the reserve. We compare a subsidy per hectare of reserve with an auction scheme and an agglomeration malus. We find that the auction is superior to the uniform subsidy for cost-efficiency. The agglomeration malus does better than the auction for the spatial pattern but is more costly.; L'objectif de cet article est de comparer différents instruments de politique pour la conservation des habitats naturels sur les terres agricoles, lorsque la disposition spatiale recherchée pour la réserve est une mosaïque aléatoire. Les auteurs utilisent un modèle de programmation mathématique spatialement explicite qui simule le comportement des exploitants agricoles, qui maximisent leur profit sous des contraintes techniques et administratives. Face à différentes politiques publiques, chaque exploitant agricole choisit, pour chaque parcelle, l'usage des sols et les pratiques appliquées, ce qui détermine le paysage au niveau régional. Un indicateur spatial (fonction Ripley L) est ensuite calculé pour le paysage obtenu, indiquant le degré de dispersion de la réserve. Les auteurs comparent une subvention par hectare de réserve, un mécanisme d'enchère et un système de malus d'agglomération. Les auteurs montrent que l'enchère est plus efficiente que la subvention en termes de coûts de la politique mise en place. Le malus d'agglomération atteint un meilleur résultat que l'enchère en termes de disposition spatiale de la réserve mais est plus coûteux.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2019-08-30T20:05:56Z No. of bitstreams: 1 DAVID CANDEIA MEDEIROS MAIA – DISSERTAÇÃO (PPGCC) 2012.pdf: 1201074 bytes, checksum: cab41798efed95712a85f9cfc1fb70d3 (MD5) Made available in DSpace on 2019-08-30T20:05:56Z (GMT). No. of bitstreams: 1 DAVID CANDEIA MEDEIROS MAIA – DISSERTAÇÃO (PPGCC) 2012.pdf: 1201074 bytes, checksum: cab41798efed95712a85f9cfc1fb70d3 (MD5) Previous issue date: 2012-07-12 Capes Na última década acompanhou-se o crescimento de um novo mercado na computação denominado de Computação na Nuvem. Este mercado tem por base a oferta de três serviços principais: (i) recursos computacionais virtuais sob demanda, por exemplo, processamento e armazenamento – serviço este denominado de Infraestrutura como Serviço (do inglês, Infrastructure as a Service – IaaS); (ii) plataformas que facilitam o desenvolvimento de novas aplicações – serviço este denominado de Plataforma como Serviço (do inglês, Platform as a Service – PaaS); (iii) aplicações prontas para uso – serviço este denominado de Software como Serviço (do inglês, Software as a Service – SaaS). Empresas que ofertam software como serviço (provedores de SaaS) podem planejar e montar sua infraestrutura de Tecnologia da Informação (TI) fazendo uso de recursos computacionais obtidos junto às empresas que ofertam recursos computacionais (provedores de IaaS). O modelo de negócio utilizado por provedores de IaaS prevê que recursos computacionais possam ser reservados com antecedência mediante pagamento de uma taxa de reserva. A reserva de um recurso garante aos contratantes deste serviço que lhes serão cobradas tarifas reduzidas quando do uso dos recursos computacionais. Realizar um planejamento de capacidade de longo prazo para estimar a quantidade de recursos necessários para execução de uma carga de trabalho e, assim, estabelecer bons contratos de reserva junto aos provedores de IaaS é uma das etapas do gerenciamento de infraestruturas de TI a ser realizada pelo provedor de SaaS. Esta dissertação apresenta duas heurísticas para realização do planejamento de capacidade: heurística UT e RF. Tais heurísticas consideram o modelo de utilidade desenvolvido nesta dissertação para estimar a quantidade de recursos a serem reservados. A avaliação realizada utiliza um modelo de simulação que considera a carga de trabalho de uma aplicação de comércio eletrônico. Em todos os cenários avaliados UT e RF apresentaram valores positivos de utilidade, com RF apresentando uma maior margem de utilidade em relação a uma estratégia base que não realiza reserva de recursos. Por fim, foi descoberto que, de acordo com a qualidade da predição da carga de trabalho, pode-se realizar uma escolha mais criteriosa dentre as heurísticas propostas. In the last decade we have seen the advent and growth of the Cloud Computing market. This market is based on offering three main services: (i) virtual on-demand computing resources such as storage and processing – this service is called Infrastructure as a Service (IaaS); (ii) platforms that facilitate the development of new applications – this service is called Platform as a Service (PaaS); (iii) software and data hosted on the cloud – this service is called Software as a Service (SaaS). SaaS providers can plan and build their Information Technology (IT) infrastructure making use of computing resources offered by IaaS providers. The business model used by IaaS providers states that computing resources can be reserved in advance by paying a reservation fee. A reserved resource has the advantage that its usage fee is lower than the usage fee of non-reserved resources. Capacity planning is one step in the IT infrastructure management performed by a SaaS provider that helps to estimate the amount of resources required to execute a future workload and thus establish good reservation contracts with IaaS providers. This dissertation presents two capacity planning heuristics: (i) heuristic based on resources utilization rates – UT; (ii) heuristic based on queue networks – RF. These heuristics consider an utility model based on the SaaS provider profit. The evaluation of such heuristics uses a simulation model that considers an e-commerce workload. In all scenarios evaluated UT and RF presented positive utility values and RF presented the best utility gains compared to a strategy that does not reserve resources. Finally, we discovered that according to the quality of the workload prediction that is used by a SaaS provider a better choice can be done among proposed heuristics.

Classification JEL : D62; H23; L11; This paper examines the effect of emission taxes on pollution abatement and social welfare, when abatement goods and services are provided by a Cournot oligopoly with free-entry. We point out initially that a higher tax not only increases demand for abatement; it also makes polluters less sensitive to price. This attracts a larger number of abatement suppliers while possibly inducing each one of them to produce less. Total abatement always goes up, however, when the delivery of abatement goods and services exhibits decreasing returns to scale. We then calculate the welfaremaximizing-emission tax and compare it to the Pigouvian tax.; Cet article s'intéresse aux effets d'une taxe par unité de pollution lorsque les biens et services de dépollution sont produits par une industrie en oligopole de Cournot avec libre entrée. Les auteurs montrent qu'une hausse de la taxe augmente la demande de dépollution et diminue la sensibilité de cette demande au prix. Ceci attire un plus grand nombre d'entreprises de dépollution sur le marché, avec une baisse possible de la production individuelle. La production totale des entreprises de dépollution augmente néanmoins toujours en présence de rendements d'échelle décroissants. Les auteurs calculent ensuite le taux de taxe optimal et ils le comparent au taux Pigouvien.

Made available in DSpace on 2022-06-22T23:20:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-21 The burnout syndrome is defined as a health impairment derived from work, more specifically, the result of a prolonged exposure to stress in the work situation. However, it has also been described among students, although not yet fully exercising a profession, the study itself, internships and other academic activities may become significant sources of stress. This study investigates burnout in a sample of medical students from the city of Fortaleza that were regularly enrolled in medical courses and regularly attending classes. The sample, for convenience, was 300 students, in average, 22.58 years old, with 48.3% men and 51.7% women. The instrument used for the detection and measurement of the syndrome was the MBI-SS (Maslach Burnout Inventory - Students Survey). The student version of the burnout inventory (MBI-SS) was developed to assess the syndrome in students and has fewer items than the original version of the instrument. The inventory measures three dimensions: Emotional Exhaustion (EE), Cynism (CY) and Professional Efficacy (PE). A questionnaire containing socio-demographic information on age, gender, satisfaction with the course, free time, leisure time, costs with the course etc.; and a third called the International Physical Activity Questionnaire, IPAQ (long version 6) were also applied in order to verify if these variables have some influence on the onset of burnout among the students surveyed. The results, analyzed by means of multidimensional regression and chi-square tests, showed that, according to the criteria used nationally, the graduate students of the sample show no symptoms of burnout and that 51.2% of the students sample can be considered sedentary and insufficiently active. Moreover, there was no relationship between the practice of physical activities and the syndrome scales EE and CY. In the scale EP the level of physical activity was found to be a predictor variable, but the relationship was not in the expected direction. It was concluded that students in the sample, although considered as not showing signs of burnout, have a low physical activity index, which allows us to assert that, at least in the students surveyed, the level of physical activity does not minimize the effects of the stress of the medical course. Keywords: Burnout syndrome, stress, physical activity, medical students. A síndrome de burnout é definida como um comprometimento decorrente do trabalho, mais especificamente da exposição prolongada ao estresse na situação de trabalho. No entanto, tem sido descrita também entre estudantes, pois, embora ainda não estejam exercendo uma profissão plenamente, o próprio estudo, estágios e outras atividades acadêmicas podem se constituir em fontes de estresse. Este estudo investigou a síndrome de burnout em uma amostra de estudantes de medicina da cidade de Fortaleza, que se encontravam regulamente matriculados nos cursos de medicina da cidade e frequentando periodicamente as aulas. A amostra, por conveniência, foi de 300 alunos com idade média de 22,58 anos, sendo 48,3% homens e 51,7% mulheres. Os instrumentos utilizados para a detecção e mensuração da síndrome foram o MBI-SS (Maslach Burnout Inventory Students Survey). A versão para estudantes do inventário de burnout (MBI-SS) foi desenvolvida para avaliar a síndrome em estudantes e possui um número menor de itens do que a versão original do instrumento. O inventário mede três dimensões: Exaustão Emocional (EE), Descrença (DE) e Eficácia Profissional (EP). Um questionário com questões sociodemográficas, contendo informações sobre idade, gênero, satisfação com o curso, tempo livre, horas de lazer, ajuda de custo etc; e um terceiro denominado Questionário Internacional de Atividade Física, IPAQ (versão 6 longa) foram também aplicados com o objetivo de verificar se essas variáveis têm alguma influência no aparecimento do burnout nos estudantes investigados. Os resultados, analisados por meio de regressão multidimensional e testes de Qui-Quadrado mostraram que, segundo o critério utilizado nacionalmente, os alunos de graduação em medicina, da amostra pesquisada, não apresentam sintomas de burnout e que 51,2% dos estudantes da amostra podem ser considerados sedentários e pouco ativos. Além disso, não foram encontradas relações entre a prática de atividades físicas e a síndrome nas escalas EE e DE. A escala EP apresentou, como variável preditora, o nível de atividade física, mas as relações não foram no sentido esperado. Conclui-se que os estudantes da amostra, embora não possam ser considerados como apresentando burnout, possuem um índice de atividade física baixa, o que permite afirmar que, pelo menos nos estudantes investigados, o nível de atividade física não minimiza os efeitos do estresse do curso de medicina. Palavras-chave: Síndrome de burnout, estresse, atividade física, estudantes de medicina.

Cet article étudie avec un regard nouveau la subvention environnementale lorsque les pollueurs achètent leur bien ou service de dépollution auprès d’une industrie spécialisée, dite éco-industrie. L’éco-industrie est ici oligopolistique. Le régulateur est donc confronté à une double distorsion : la pollution et l’imperfection de la concurrence dans l’industrie de l’environnement. Nous montrons que la combinaison d’une taxe sur la pollution et d’une subvention aux pollueurs par unité de dépollution ne permet pas d’atteindre l’optimum social alors qu’on obtient la conclusion inverse lorsque la subvention est adressée à l’éco-industrie, par unité de production. Lorsqu’il existe des coûts de transfert des fonds publics, il peut être préférable d’utiliser la taxe environnementale seule., This paper considers the combination of pollution taxes and abatement subsidies when some polluting firms procure their abatement goods and services from an oligopolistic eco-industry. The regulator must here cope with two simultaneous price distortions: one that comes from pollution and the other which is caused by the eco-industry's market power. In this context, we show that taxing emissions while subsidizing polluters' abatement efforts cannot lead to first-best, but the opposite occurs provided it is the eco-industry's output which is subsidized. When public transfers also create distortions, welfare can be higher if the regulator uses only an emission tax, but subsidizing abatement suppliers while taxing emissions remains optimal when the eco-industry is concentrated.

International audience; This paper compares, in a polluting oligopoly, an emission tax and a form of environmental policy calledvoluntary agreement (VA). Here there are two ways of reducing pollution: output contraction and end-of-pipe abatement. Given the imperfect competition, firms’ reaction to the tax is sub-optimal. They reduceoutput excessively in order to raise the price and do not abate enough. The VA is a take-it-or-leave-it con-tract on abatement effort, offered to the firms with the threat of a tax. It has a limited effect on output andalways allows higher abatement than the tax. We find that this kind of VA may be more efficient than thetax in a concentrated industry, when pollution is not too harmful and when the abatement technology israther efficient and cheap.; L'auteur compare, dans un oligopole polluant, une taxe sur la pollution et une forme de régulation environnementale dite "approche volontaire" (AV). Il existe deux façons de réduire la pollution : la réduction de la quantité produite et la dépollution en bout de chaîne. Etant donnée la concurrence imparfaite, la réaction des firmes polluantes face à la taxe est sous-optimale. Elles réduisent leur production de manière excessive et n'investissent pas suffisamment dans la dépollution. L'AV est un contrat à prendre ou à laisser offert aux pollueurs avec la menace d'une taxe. Cette forme d'AV a un impact limité sur la production et engendre toujours une dépollution supérieure à la taxe. L'auteur montre que cet instrument peut être plus efficace que la taxe d'un point de vue social dans une industrie relativement concentrée et lorsque la dépollution est relativement efficace et peu coûteuse.

This paper re-examines environmental regulation, under the assumption that pollution abatement technologies and services are provided by an imperfectly competitive environment industry. It is shown that each regulatory instrument (emission taxes and quotas; design standards; and voluntary agreements) has a specific impact on the price-elasticity of the polluters’ demand for abatement services, hence on the market power of the eco-industry and the resulting cost of abatement. This implies that the optimal pollution tax will be higher than the marginal social cost of pollution, while a voluntary approach to pollution abatement may fail unless the eco-industry itself is willing to participate.

This paper re-examines environmental regulation, under the assumption that pollution abatement technologies and services are provided by an imperfectly competitive environment industry. It is shown that each regulatory instrument (emission taxes and quotas; design standards; and voluntary agreements) has a specific impact on the price-elasticity of the polluters' demand for abatement services, hence on the market power of the eco-industry and the resulting cost of abatement. This implies that the optimal pollution tax will be higher than the marginal social cost of pollution, while a voluntary approach to pollution abatement may fail unless the eco-industry itself is willing to participate., Cet article ré-examine la réglementation environnementale, sous l'hypothèse additionnelle que les technologies et services de dépollution sont fournis par une industrie de l'environnement en concurrence imparfaite. On montre que chaque instrument de réglementation (taxes et quotas sur les émissions; normes obligatoires; accords volontaires) possède un impact spécifique sur l'élasticité-prix de la demande de biens et services environnementaux et, par voie de conséquence, sur le pouvoir de marché des éco-entreprises et les coûts assumés par les pollueurs. Il s'ensuit, par exemple, qu'une taxe optimale sur les émissions polluantes devra dépasser le coût social marginal de la pollution, tandis qu'une approche volontaire à la réduction de la pollution ne pourra fonctionner que si la participation de l'éco-industrie (et non seulement des seuls pollueurs) est acquise.

International audience; Cet article compare, dans un oligopole polluant, une taxe par unité de pollution et une forme de régulation environnementale dite approche volontaire (AV). En réduisant la quantité produite par les firmes, la taxe amplifie la distorsion due à la concurrence imparfaite et est sous-optimale. L’AV est ici un contrat sur l’effort de traitement de la pollution que les firmes peuvent accepter ou non, sachant que, si elles le refusent, elles payent la taxe. Cette forme d’AV limite l’impact de la réduction de la pollution sur la quantité produite en incitant uniquement au traitement de la pollution en fin de processus de production. Étant donné les hypothèses posées, on obtient une condition nécessaire et suffisante sur les paramètres pour laquelle ce type d’AV est plus efficace que la taxe. Cette condition est vérifiée pour réguler une industrie concentrée et une forme de pollution relativement peu nuisible et facile à traiter.

L’ambition de l’étude Inra "EFESE-EA" est de décrire les mécanismes et déterminants de la fourniture des services écosystémiques par les écosystèmes agricoles sur la base d'une revue des connaissances existantes, et de procéder à leur évaluation à l’échelle nationale sur la base d’indicateurs définis dans le cadre de l’étude. L’organisation du travail, telle que prévue en début d’étude, se voulait séquentielle : (1) identification et spécification biophysiques d’une liste de biens agricoles et services écosystémiques ; (2) évaluation biophysique : quantification du niveau de fourniture des biens et services identifiés à l’étape (1) (3) évaluation économique : quantification de la valeur économique des services (le plus souvent dans une unité monétaire) Dans le temps imparti à l’étude, le collectif d’experts a donné la priorité aux volets biophysiques (1) et (2) afin : - d’instruire de façon robuste la conceptualisation des biens et services (volet 1) : ce travail constitue un front de recherche actuel, associé à une littérature académique abondante mais parfois non stabilisée, que le collectif d’experts s’est attaché à analyser de façon à proposer des choix de conceptualisation argumentés ; - de pousser au maximum l’exercice d’évaluation biophysique (volet 2) dans le cadre de la demande initiale formulée par le MEEM : cartographier la production d’un large panel de biens agricoles et les SE rendus par les écosystèmes agricoles à la résolution spatiale la plus fine possible, et à l’échelle France entière. A noter que le présent exercice ne constituant pas un projet de recherche mais bien une étude institutionnelle Inra (au sens des procédures DEPE), l’ensemble des évaluations développées dans le présent rapport est réalisée à partir de données existantes, aucun travail d’expérimentation visant à acquérir de nouvelles données de terrain n’ayant été conduit. Il résulte de ce choix de priorisation que : - le volet d’évaluation économique (3) est initié pour quelques SE mais peu développé en comparaison des volets (1) et (2) ; - tout en veillant à élaborer des méthodologies d’évaluation biophysiques traçables et robustes, les experts ont pris le parti de proposer des méthodologies plus exploratoires pour quelques SE pour lesquels les données actuelles ne permettent pas d’évaluer directement le niveau de fourniture à l’échelle France entière : dans ces cas particuliers (signalés explicitement dans les sections du rapport dont ils font l’objet), les méthodologies ont été mises en œuvre jusqu’à la réalisation des cartographies dans le but de donner à voir le potentiel qu’offrent ces méthodologies et la nature des résultats qu’elles peuvent produire sous condition de leur validation France entière, plutôt que dans le but d’interpréter pour eux-mêmes les résultats obtenus. Les experts se sont alors particulièrement attachés à relativiser les résultats quantitatifs ainsi produits, et à accompagner les cartographies d’un descriptif détaillé des protocoles de validation qu’il faudrait mettre en œuvre dans les suites de l’étude pour stabiliser et valider ces méthodologies exploratoires. Ce parti pris du groupe de travail EFESE-écosystèmes agricoles est compatible avec l’objectif poursuivi dans le programme EFESE, qui se donne pour objectif de produire un guide méthodologique pour l’évaluation des biens et SE en en pointant les limites, difficultés, précautions et améliorations possibles associées à chacune des pistes avancées.