Dans le contexte des changements environnementaux en cours et face aux pressions anthropiques, la préservation des milieux forestiers tropicaux est devenue un enjeu majeur. C’est dans ce cadre que l’île de Madagascar a mis en place une nouvelle politique forestière à partir des années 1990, avec la création d’Aires Protégées. Le Parc de Ranomafana a ainsi été créé en 1991 et classé au patrimoine mondial en 2007. La mise en place d’un suivi des dynamiques paysagères à l’échelle locale, par le biais de l’imagerie satellitaire optique (SPOT, Landsat, MODIS), permet de suivre, sur des périodes récentes (particulièrement 1990-2014), l’évolution des milieux forestiers et de certaines cibles de conservation définies par le Par cet sur le plan international, à la lumière de certaines variations bioclimatiques (pluviométriques notamment) ou anthropiques (agro-sylvo-pastorales). Ce suivi permet d’observer les trajectoires au cours des trois dernières décennies et de pointer les principales évolutions paysagères ainsi que le poids des variations des conditions climatiques et d’usages des terres sur les dynamiques de la végétation. La tendance est à la diminution du couvert forestier, essentiellement au détriment de la forêt de basse altitude. Le taux de dégradation forestière durant les 25 années étudiées est estimé à 0,62 %/an, ces variations étant différentes en fonction de l’éloignement au Parc. De plus, l’analyse de l’activité photosynthétique révèle une diminution générale des valeurs sur la période d’étude, quel que soit le type de formation végétale étudié.Mots-clés : Madagascar, parc national, télédétection satellitaire, forêts tropicales, pressions anthropiques, changements d’occupation du sol / In the context of currents environmental changes, and deal with anthropogenic pressures, the preservation of tropical forest has become a major issue. In this context, Madagascar island has implemented a new forest policy since 1990, having garnered the creation of protected areas. Ranomafana National Park has been created in 1991 and classify as World heritage in 2007. The establishment of a landscape dynamics monitoring at the local level, using remote sensing, allow analysis of forest changes faces anthropogenic pressures, taking into account the specificities of the study area. This monitoring allows to observe past and crurrent pressures on forest and point landscape trajectories. In addition, the forest bioclimatic activity monitoring examines the impact of climatic conditions and land use change on vegetation dynamics. The trend is the global reduction of forest cover mainly of lowland forest. Forest degradation rate during these past 25 years is estimated at 0,62%/year. These variations are different depending on the distance to the Park. Furthermore, analysis of photosynthetic activity reveals a general decline in values over the study period, regardless of the plant community type studied.Keys-words : Madagascar, remote sensing, tropical forests, Land-use change

This dissertation consists of three essays that apply both economic theory and econometric methods to understand design and dynamics of institutions. In particular, it studies how institutions aggregate information and deal with uncertainty and attempts to derive implications for optimal institution design. Here is a brief summary of the essays. In many economic, political and social situations where the environment changes in a random fashion necessitating costly action we face a choice of both the timing of the action as well as choosing the optimal action. In particular, if the stochastic environment possesses the property that the next environmental change becomes either more or less likely as more time passes since the last change (in other words the hazard rate of environmental change is not constant over time), then the timing of the action takes on special importance. In the first essay, joint with Maxwell B Stinchcombe, we model and solve a dynamic decision problem in a semi-Markov environment. We find that if the arrival times for state changes do not follow a memoryless process, time since the last observed change of state, in addition to the current state, becomes a crucial variable in the decision. We characterize the optimal policy and the optimal timing of executing that policy in the differentiable case by a set of first order conditions of a relatively simple form. They show that both in the case of increasing and decreasing hazard rates, the optimal response may be to wait before executing a policy change. The intuitive explanation of the result has to do with the fact that waiting reveals information about the likelihood of the next change occurring, hence waiting is valuable when actions are costly. This result helps shed new light on the structure of optimal decisions in many interesting problems of institution design, including the fact that constitutions often have built-in delay mechanisms to slow the pace of legislative change. Our model results could be used to characterize optimal timing rules for constitutional amendments. The paper also contributes to generalize the methodology of semi-Markov decision theory by formulating a dynamic programming set-up that looks to solve the timing-of-action problem whereas the existing literature looks to optimize over a much more limited set of policies where the action can only be taken at the instant when the state changes. In the second essay, we extend our research to situations, where the current choice of action influences the future path of the stochastic process, and apply it to the legal framework surrounding environmental issues, particularly to the ‘Precautionary Principle' as applied to climate change legislation. We represent scientific uncertainty about environmental degradation using the concept of 'ambiguity' and show that ambiguity aversion generates a 'precautionary effect'. As a result, justification is provided for the Precautionary Principle that is different from the ones provided by expected utility theory. This essay serves both as an application of the general theoretical results derived in the first essay and also stands alone as an analysis of a substantive question about environmental law. Prediction markets have attracted public attention in recent years for making accurate predictions about election outcomes, product sales, film box office and myriad other variables of interest and many believe that they will soon become a very important decision support system in a wide variety of areas including governance, law and industry. For successful design of these markets, a thorough understanding of the theoretical and empirical foundations of such markets is necessary. But the information aggregation process in these markets is not fully understood yet. There remains a number of open questions. The third essay, joint with Robert Lieli, attempts to analyze the direction and timing of information flow between prices, polls, and media coverage of events traded on prediction markets. Specifically, we examine the race between Barack Obama and Hillary Clinton in the 2008 Democratic primaries for presidential nomination. Substantively, we ask the following question: (i) Do prediction market prices have information that is not reflected in viii contemporaneous polls and media stories? (ii) Conversely, do prices react to information that appears to be news for pollsters or is prominently featured by the media? Quantitatively, we construct time series variables that reflect the "pollster's surprise" in each primary election, measured as the difference between actual vote share and vote share predicted by the latest poll before the primary, as well as indices that describe the extent of media coverage received by the candidates. We carry out Granger Causality tests between the day-to-day percentage change in the price of the "Obama wins nomination" security and these information variables. Some key results from our exercise can be summarized as follows. There seems to be mutual (two-way) Granger causality between prediction market prices and the surprise element in the primaries. There is also evidence of one-way Granger causality in the short run from price changes towards media news indices. These results suggest that prediction market prices anticipate at least some of the discrepancy between the actual outcome and the latest round of polls before the election. Nevertheless, prices also seem to be driven partly by election results, suggesting that there is an element of the pollster’s surprise that is genuine news for the market as well. / text

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2009. / Härtill 5 uppsatser.

Chez les espèces fruitières, la dormance est une période clé qui influencera la floraison et la fructification. La dormance est finement régulée par de nombreux facteurs génétiques et environnementaux. Elle est composée de deux phases principales, l’endodormance (ou dormance « vraie ») et l’écodormance (ou dormance « environnementale »). L’endodormance est caractérisée par une incapacité totale des bourgeons à débourrer, même dans des conditions normalement propices à la croissance. C’est le froid hivernal qui permet la sortie de l’endodormance, nécessaire à la floraison puis la fructification. Les besoins en froid, quantité nécessaire de froid pour accéder à la levée de l’endodormance, sont génétiquement déterminés, et sont relativement élevés chez la plupart des variétés de cerisier doux (Prunus avium L.) comparativement à d’autres espèces. Dans un contexte de réchauffement climatique, les besoins en froid pourraient ne plus être satisfaits et conduire à des pertes économiques.. L’objectif de cette thèse est donc d’approfondir les connaissances sur les voies impliquées dans la levée d’endordormance. L’étude porte sur un panel de variétés contrastées pour leurs besoins en froid, depuis des variétés très précoces comme ‘Cristobalina’ jusqu’à des variétés très tardives comme ‘Fertard’. Des approches métabolomiques, moléculaires et d’apport exogène de molécules ont été utilisées. Les résultats montrent que les voies 1) hormonales, 2) du stress oxydatif et 3) des sucres, ont un rôle différent. La voie des sucres donne un aperçu de l’activité métabolique ainsi que des marqueurs des différentes phases de la dormance. La voie hormonale est un système permettant de contrôler la croissance sans lien causal sur la dormance. La voie du stress oxydatif indique que les variétés précoces sont dans un état globalement plus oxydé que les variétés tardives lors de cette période. Les données de RNA-seq permettent l’identification de gènes ayant un rôle majeur dans la dormance et de confirmer les hypothèses des mécanismes impliqués. Ces résultats seront déterminants pour la création de variétés adaptées aux conditions climatiques futures. / Among fruit tree species, dormancy is a key period determining the success of flowering and fruit producing. Dormancy is tightly regulated by numerous genetic and environmental factors. It can be divided in two main phases: endodormancy (“true dormancy”) and ecodormancy (“environmental dormancy”). Endodormancy is characterized by a total incapacity of buds to burst, even in conditions proper to growth. Winter chilling enables the end of endodormancy, necessary for flowering and fruit production. Chilling requirements, necessary amount of chill for endodormancy release, are genetically fixed and relatively elevated in sweet cherry (Prunus avium L.) varieties compared to other species. In a climate change context, chilling requirements may not be entirely fulfilled and lead to drastic economic losses. The objective of this work is to increase the knowledge on the pathways involved in endodormancy release. The study relies on a panel of varieties contrasted for their chilling requirements, varying from a very low chill cultivar ‘Cristobalina’ to a high chill cultivar ‘Fertard’. Metabolomics and molecular studies, and exogenous molecules supply were used for dormancy deciphering. Hormonal pathway, oxidative stress and sugar pathway seem to have different roles. Sugar pathway enables to have an overview of the metabolic activity, and may be used as molecular markers to identify dormancy phases. Hormonal pathway has a role on growth control but no causal link with dormancy release was assessed. Major results concern the role of oxidative stress, with low chill cultivars in a more oxidized status than high chill cultivars. Moreover, RNAseq data enable the identification of key genes controlling dormancy and confirms the hypothesis on mechanisms involved. These results will be crucial for breeding new verities well adapted to future climatic conditions.

Made available in DSpace on 2014-10-09T12:53:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:33Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Orientador: Henrique César da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-17T04:24:59Z (GMT). No. of bitstreams: 1 Galvao_DaianeMartins_M.pdf: 8796315 bytes, checksum: 70e7c512b34c6d5499b1eb940078d7a0 (MD5) Previous issue date: 2010 / Resumo: Esta pesquisa teve por objetivo compreender como o Exame Nacional do Ensino Médio (ENEM) materializa, na forma de questões, a temática das Mudanças Climáticas Globais, considerando as Geociências como aspecto dessa significação, uma perspectiva epistemológica que nos permite uma visão específica desse tema. Essa temática pode e vem sendo significada por diversos meios a partir de diferentes perspectivas, direções de sentidos, produzindo diferentes versões. Foi investigada a possível presença e influência da perspectiva das Geociências nas versões produzidas pelo ENEM sobre essa temática e verificado que o discurso apresentado pelo ENEM tende a direcionar para um determinado sentido, como se fosse o único possível, silenciando o fato da pluralidade de perspectivas de considerar esse tema. O estudo foi feito a partir da análise de quinze questões que abordam diretamente essa temática, que foram selecionadas após uma análise inicial de dez provas do ENEM, no período de 1998 a 2007, sendo utilizadas contribuições advindas de estudos de linguagem como referencial teórico-metodológico, notadamente aqueles que definem uma certa concepção de discurso, como produção histórico-social, e no que se refere à questão da textualização e interpretação; e contribuições da epistemologia das Geociências, como dispositivo analítico construído para as análises. A análise focou o processo de produção do discurso, considerou o texto analisado como parte desse processo e não apenas os 'conteúdos' das questões ou suas condições externas de produção, levando em conta a natureza histórico-social do texto, buscando entender como os modos dessas textualizações se aproximam ou limitam as questões de uma abordagem geocientífica. Esse olhar, para as avaliações do ENEM, permitiu avançar os limites da constatação de equívocos conceituais, para compreender o processo pelo qual o campo epistemológico das Geociências intervém como condição de produção da textualização dessa temática. Este trabalho faz parte de um projeto mais amplo, desenvolvido em rede com outras instituições (UFSCar e UFSC), e apoiado Observatório da Educação/CAPES/INEP / Abstract: This research aimed to understand how the High School National Examination (ENEM) embodies, in the form of questions, the theme of Global Climate Change, considering the Geosciences as aspect of this significance, as an epistemological perspective that allows us a deeper insight about the subject. This theme can and has been signified by different means from different perspectives directions of interpretations, producing different versions. We investigated the possible presence and the influence from the perspective of Geosciences in versions produced by ENEM on this topic and confirmed that the discourse made by ENEM tends toward a certain meaning direction and places it as if it were the only possibility, silencing the fact of plurality of perspectives to consider this theme. The discussion was based on analysis of fifteen questions that directly address this theme that were selected after an initial analysis of the ten exams of ENEM, in the period of 1998 to 2007, using contributions from studies of language as theoretical and methodological framework, especially those that set a certain conception of discourse, as a historical-social production, and in relation to the case of textualization and interpretation, and contributions of the epistemology of Geosciences, built as analytical device for analysis. The analysis focused on the production process of the discourse, considered the text as part of that process and not just the 'content' of the issues or their external conditions of production, taking into account the historical and social nature of the text, seeking to understand as the way these textualizations are close to a geoscientific approach. This look to the evaluations of ENEM allowed to proceed beyond finding of the conceptual errors, to understand the process by which the epistemological field of Geosciences operates as a condition of production of textualization of this theme. This work is part of a larger project, developed by networking with other institutions (UFSC and UFSCar), and supported by the Observatório da Educação (Education Observatory)/ CAPES / INEP / Mestrado / Mestre em Ensino e Historia de Ciencias da Terra

Made available in DSpace on 2014-10-09T12:53:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:33Z (GMT). No. of bitstreams: 0 / Nos últimos anos, o Protocolo de Quioto é um assunto que vem sendo bastante discutido, inicialmente, em um nicho restrito, principalmente os acadêmicos e profissionais ligados à área de mudanças climáticas. Com sua entrada em vigor, em fevereiro de 2005, o assunto rompeu as fronteiras iniciais e ganhou espaço na mídia, de forma que hoje é comum assistir as reportagens sobre o mesmo nos meios de comunicação de massa. Dada a ampla divulgação do tema, o presente trabalho pretende discutir a utilização de um mecanismo de flexibilização previsto nesse protocolo, para contribuir na viabilização do aproveitamento do gás gerado em aterros sanitários utilizando células a combustível de óxido sólido. Dentre os três mecanismos apresentados no Protocolo de Quioto, o mecanismo de desenvolvimento limpo (MDL) disposto pelo artigo 12, é o único que pode ser implementado por países que não estão listados no anexo I, caso do Brasil. Por outro lado, a questão da gestão de resíduos sólidos no Brasil é extremamente deficitária. Apesar de ser ilegal, a maioria dos resíduos é destinada para \"lixões\", degradando tanto o meio ambiente natural como as comunidades próximas e conseqüentemente, emitindo gases de efeito estufa (GEE), que estão cada vez mais desregulando o sistema climático global. A remediação ambiental dessas áreas contaminadas por esses lixões e construção de aterros sanitários para substituí-los, entendendo o aterro sanitário como um bioreator, e a utilização do biogás para a geração de energia pode contribuir para melhorar o quadro em que nos encontramos. A utilização da tecnologia alternativa inovadora de células a combustível de óxido sólido (SOFC - Solid Oxide Fuel Cell) ao invés de uma convencional trará ganhos tanto ambientais como em eficiência energética. Dentre as várias barreiras para uma maior utilização das células a combustível, o custo é apontado como a principal. Neste contexto, a SOFC é a que possui o maior custo dentro de todas as tecnologias de células a combustível, e neste sentido, a utilização do MDL pode contribuir para sua viabilização. Foram elaborados cenários para as potências instaladas de 250 kW, 500 kW, 1.000 kW, 5.000 kW e 10.000 kW utilizando o biogás do Aterro Municipal de Santo André. Os cálculos foram realizados de acordo com as duas modulações de cálculo da ACM0002 para o fator de emissão, sendo ex ante e ex post. Comparando os custos para a instalação das potências estudadas com os cálculos de reduções de emissões, que constituem uma potencial receita, os custos se apresentam superiores; entretanto, outras receitas advindas da venda da energia e receitas da disposição dos resíduos sólidos devem ser levados em consideração na tomada de decisão de investimento em projetos dessa natureza. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Orientador: Celso Dal Ré Carneiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-21T23:35:28Z (GMT). No. of bitstreams: 1 MalaquiasJunior_JoseRoberto_M.pdf: 4309832 bytes, checksum: 8d3bfe13ccb23e0930724eab25f12c08 (MD5) Previous issue date: 2013 / Resumo: Problemas ambientais e sociais parecem ser cada vez mais evidentes e crescentes em todas as partes do planeta. A população tem sido alertada sobre os fatos e convidada a participar, mas raramente se reconhece que tudo pode ter início no local onde cada um vive. A escola é essencial no processo, mas alunos e professores geralmente são incapazes de transpor conhecimentos sobre o local onde vivem e estabelecer interrelações com a escala global ou planetária. Esta pesquisa tem como principal objetivo elaborar e avaliar a aplicação de materiais didáticos digitais em Geociências, com ênfase no conhecimento local sobre o município de Monte Mor, SP. A hipótese básica a ser pesquisada é a de que a contribuição das Geociências é essencial para formação de uma sociedade comprometida para com o próximo e com o planeta. Projetos de Educação Ambientais previamente conduzidos na rede educacional pública e privados do município permitiram concluir que a falta de conhecimentos sobre o local onde o aluno vive dificulta sua motivação e sucesso escolar. Se, por um lado, as Geociências favorecem ações interdisciplinares, por outro, o computador facilita a divulgação de informações, pois oferece tanto dados de caráter local, como permite, pela internet, visitar pontos remotos do planeta. Considerando-se que o ensino de Geociências pode construir pontes entre a realidade local e questões socioambientais e, ao mesmo tempo, acentuar as interrelações com o contexto global, o Módulo Monte Mor do projeto Geo-Escola forneceu informações, imagens e mapas geológicos locais a professores de educação básica. Antes de trabalhar situações atuais com o aluno, precisamos prepará-lo para que ele problematize e seja capaz de buscar respostas por si mesmo; isso é possível, se estudarmos o passado recente e o passado geológico, estabelecendo assim o elo de ligação com o quadro atual. Foi previsto uso dos recursos em salas de aula, laboratórios de informática e um portal web. No Projeto desenvolveu-se trabalho junto a alunos e professores, oferecendo-lhes um material didático desenvolvido em ambiente de software livre que organiza mapas e informações locais, e possibilitando estabelecer elos entre o global e o local. As ações realizadas ampliaram o horizonte de ensino de diferentes disciplinas. Embora ainda não se tenha atingido plena interdisciplinaridade, o Módulo Monte Mor deixou claro que é possível, por intermédio das Geociências, fazer as aplicações e transposições requeridas. Conclui-se que uma educação voltada para a compreensão modificará profundamente o ensino atual, condição necessária para transformar as relações entre seres humanos, parte integrante do dinâmico planeta que habitamos / Abstract: Environmental and social problems seem to be increasingly evident and growing in all parts of the planet. The population has been alerted to the facts and invited to participate of some decisions, but seldom acknowledges that everything may start at the place where a person lives. Schools are essential for enhancing public enlightenment, but students and teachers are often unable to establish a relationship with global-scale or planetary phenomena from the local knowledge. The main objective of this research is to develop and to evaluate an implementation of digital learning materials in Geosciences with emphasis on local knowledge about the municipality of Monte Mor, São Paulo State, Brazil. The basic hypothesis to be investigated is that the contribution of Geosciences is essential to enhance commitment by a society towards other people and the planet. Previous Environmental Education Projects conducted in the county school system help to conclude that the lack of knowledge about where one student lives hinders his/her motivation and limits his/her potential academic success. If the Geosciences favor interdisciplinary actions, the computers facilitate the dissemination of information, as long as they offer both local data and help visiting remote points of the planet, by internet. Geosciences teaching can build bridges between local realities and environmental issues; at the same time, it helps understanding the relationship with the global context. Thus, the Monte Mor Module of the Geo-School Project has provided information, images and geological maps to basic education teachers, including information on where the student lives. The resources were expected to be used in classrooms and computer labs of the public and private educational network in the municipality. Before a student to work with present situations, it is necessary to prepare him/her so that he/she problematizes and be able to find answers by himself/herself. This is possible when studying the ancient geological past and the more recent past, thus establishing the links. The project involved didactic training of teachers of different disciplines. Although it has been not yet reached a full interdisciplinarity, the Monte Mor Module made it clear that it is possible, by means of Geosciences, to make the applications and transpositions required. An education focused on "understanding" will deeply modify the current ways of teaching. At the same time, this can be a necessary condition to transform the relations between human beings, as part of the dynamic planet we all inhabit / Mestrado / Ensino e Historia de Ciencias da Terra / Mestre em Ensino e Historia de Ciencias da Terra