O sistema vascular das lianas, em especial o xilema, mostrou−se repetidas vezes distinto nas lianas, com aspectos compartilhados mesmo dentre linhagens distantemente relacionadas, tais como a presença de variações cambiais, vasos mais largos e longos, parênquima axial mais abundante − frequentemente não−lignificado − raios mais altos e largos − geralmente heterocelulares. Não obstante todo esse conhecimento, poucos trabalhos investigaram o impacto da evolução do hábito lianescente no sistema vascular em linhagens cujos ancestrais não são lianas e sim plantas auto−suportantes. Portanto, nesta tese exploramos o lenho, o floema e a anatomia caulinar como um todo em linhagens que contêm lianas e plantas auto−suportantes, utilizando filogenias bem sustentadas e investigações anatômicas detalhadas. Em Bignoniaceae (Lamiales), investigamos em detalhe a anatomia do lenho, delimitando caracteres e estados de caráter e mapeando-os na filogenia mais recente do grupo, encontrando que modificações eco−fisiológicas e transições de hábito tiveram grande impacto na evolução do lenho na família. Anéis porosos e semi−porosos, bem como espessamento espiralado foram encontrados em plantas crescendo em latitudes mais altas ou em regimes hídricos fortemente sazonais, ao passo que fibras septadas apareceram correlacionadas com a presença de parênquima axial escasso. A evolução de lianas, por sua vez, parece ter levado a um aumento no diâmetro dos vasos, contudo dimórficos, células perfuradas de raio, parênquima axial mais escasso e surgimento de variações cambiais. Apesar da enorme diversidade dentro de Bignoniaceae, os grandes clados possuem uma anatomia bastante preditiva e 9 possíveis sinapomorfias morfológicas são sugeridas para clados delimitados somente com base em dados moleculares. Dentro das traqueófitas, investigamos 26 pares filogeneticamente controlados de lianas espécies auto−suportantes relacionadas pertencentes a todas as principais linhagens de traqueófitas (exceto licófitas), a fim de buscar caracteres que tenham evoluído em correlação com o hábito lianescente. Encontramos que os elementos crivados e os poros das placas crivadas têm sempre maior calibre nas lianas, e que os raios são mais altos e heterocelulares. Contudo, as principais características do floema das lianas se mantêm conservadas em relação às espécies auto−suportantes relacionadas, evidenciando que as lianas teriam evoluído um sistema de condução de fotossintetatos mais eficiente, porém preservando um alto sinal filogenético. Em Malpighiaceae, lianas são abundantes, tal como as variações cambiais. Contudo, pouco se sabe sobre o número de variações presentes na família ou como elas estariam distribuídas. Aqui delimitamos 6 diferentes tipos de variação cambial, que teriam evoluído independentemente 8 vezes na família, cujo ancestral é reconstruído como tendo caule simples. Muitas dessas variações compartilham estágios de desenvolvimento, ao passo que variações anatomicamente muito similares derivam de trajetórias ontogenéticas distintas. Dentro dos gêneros as variações se mostraram conservadas e mesmo dentre grupos irmãos do novo e velho mundo, evidenciando que as variações cambiais seriam bons indicadores de relações na família. De maneira geral, podemos concluir que lianas impactam significativamente o sistema vascular nas linhagens onde ocorrem e que tais modificações em geral resultam em um sistema de condução hídrico e de fotossintetatos mais eficiente e também mais flexível para a escalada. / The vascular system of lianas, especially the xylem, has been repeatedly been shown to be different, with lianas having a set of features shared among even distantly related lineages, such as the presence of cambial variants, wide and long vessels, more abundant axial parenchyma, frequently non−lignified, taller and wider rays, which are generally heterocellular. In spite of this amount of knowledge, few works have investigated the impact for the vascular system of the evolution of this habit within lineages whose ancestors are not lianas, but self-supporting plants. Therefore, in this dissertation we explored wood, phloem and overall stem−anatomy evolution in lineages that contain lianas and self−supporting plants, using well−supported phylogenies and detailed anatomical investigations. Within Bignoniaceae (Lamiales), we thoroughly investigated the wood anatomy, delimiting character states and mapping them onto the last phylogeny for the group, encountering that eco−physiological and habit transition were the main drivers of modifications in the wood anatomy in the family. Ring−porous and semi−ring porous woods and helical thickening was found in plants either growing in higher latitudes or with marked seasonal water regimes, and septate fibres correlated with scanty axial parenchyma, which are eco−physiological drivers. Evolution of lianas, in turn, drove an increase in vessel diameter, wide vessels accompanied by very narrow ones, presence of perforated ray cells, scanty axial parenchyma and cambial variants. Despite the great wood anatomical diversity within the family, major clades have quite predictive wood anatomy and 9 possible anatomical synapomorphies were raised in this work to clades previously delimitated exclusively by molecular characters. Within the tracheophytes, we investigated 26 phylogenetically controlled pairs of lianas and their self−supporting relatives within all major lineages of tracheophytes (except lycophytes), in order to seek characters evolving in correlation with the lianescent habit. We found that the sieve elements and sieve pores were always wider in the lianas, and that the rays were always taller. However, all the main characters of the phloem of the lianas remained conserved with that of their self−supporting relatives. This evidenced that although a more efficient photosynthetic conductive system evolved in the phloem of lianas, overall anatomy conserved a high phylogenetic signal. Within Malpighiaceae, lianas are abundant and many cambial variants are present. However, nothing was known regarding how many types of cambial variants there were in the family and how they were distributed. We were able to delimit 6 different types of cambial variants that evolved at least 8 times independently in the family, which ancestrally lacks a cambial variant. Many of these types share common stages of development and some variants that are anatomically very similar derive from different ontogenetic trajectories. Within the genera, the variants are conserved, and even between sister groups in the new and old world, evidencing that cambial variants may be a good indicator of relationships within the family. Overall, we conclude that lianas greatly impact the evolution of the vascular system in the lineages where they have evolved, and these modifications normally result in a more efficient water and photosynthates conduction system and an increased flexibility for climbing.

Made available in DSpace on 2016-04-25T16:45:30Z (GMT). No. of bitstreams: 1 Paula Augusta Rodrigues Coelho.pdf: 814355 bytes, checksum: fe3507ca66b0de5d265df8b55ec24ada (MD5) Previous issue date: 2010-05-31 / Investors try to capture the opportunities for capital gains offered by emerging countries by increasing the total return or reduce the risk of the portfolio. Solnik (1991, 2004) found evidence of reduced risk and increased return through international diversification. In addition, to benefits such as the development of local capital markets, the greater liquidity of shares traded and financial market development. This study aims to determine whether markets are more globalized and investigate whether there are still benefits of risk-return in the international diversification of portfolios for an investor from United States. The countries of the sample will be the three largest stock markets (U.S., Japan and England) and the BRICs (Brazil, China, Russia and India). The study refers to two periods: from January 1996 to December 2000 and from January 2003 to December 2007. In the second period (2003-2007) the market indexes are more correlated and has a higher level of NGR, ie, the markets of the sample are more global. Using the Model Portfolio Selection, met the efficient portfolio for the investor of the United States. The results show that the portfolio composed with developed countries indexes (United Kingdom, United States of America and Japan) and indexes of the countries that make up the BRIC (Brazil, Russia, India and China) has a better risk-return than the portfolio formed only by developed countries index, indicating that despite of the increased globalization, there is still diversification benefits in the developing countries / Os investidores procuram capturar as oportunidades de ganhos de capital oferecidas pelos países emergentes aumentando o retorno total ou reduzindo o risco do portfolio. Solnik (1991, 2004) encontrou evidências de redução de risco e aumento do retorno via diversificação internacional. Além de benefícios como o desenvolvimento do mercado de capitais local, a maior liquidez das ações negociadas e o desenvolvimento do mercado financeiro. Este estudo objetivou verificar se os mercados estão mais globalizados e investigar se ainda há benefícios de risco-retorno na diversificação internacional de portfólios para um investidor dos Estados Unidos. A amostra considera os 3 maiores mercados acionários (EUA, Japão e Inglaterra) e os BRICs (Brasil, China, Rússia e Índia). O estudo refere-se a dois períodos: de janeiro de 1996 a dezembro de 2000 e de janeiro 2003 a dezembro de 2007. No segundo período (2003-2007) os índices dos mercados analisados se encontram mais correlacionados e com um maior Nível de Globalização Restrita que no primeiro período, ou seja, os mercados da amostra estão mais globalizados. Usando o modelo Portfolio Selection, encontrou-se o portfólio eficiente para o investidor dos Estados Unidos. Os resultados mostram que a carteira composta pelos índices dos países desenvolvidos (Reino Unido, Estados Unidos e Japão) e pelos índices dos países que compõe o BRIC (Brasil, Rússia, Índia e China) tem uma melhor relação risco-retorno que a carteira formada somente pelos países desenvolvidos, indicando que, apesar de uma maior globalização, ainda há benefícios na diversificação nos em desenvolvimento

O objetivo do presente estudo foi verificar empiricamente as implicações da diversificação corporativa, através do efeito de coinsurance, nas finanças e no investimento corporativo através de dois canais específicos: o custo da dívida externa bancária das empresas e a probabilidade de ocorrência de covenants com restrições à investimento. Para alcançar esse objetivo, estimou-se dois modelos que controlam a endogeneidade da decisão de diversificar através da utilização de variáveis instrumentais. Não foi possível, através dos dados utilizados no estudo, evidenciar que a diversificação corporativa impacta o custo do financiamento externo bancário das empresas. O estudo encontrou evidências, ainda que fracas, de que a diversificação corporativa reduz a probabilidade de ocorrência de covenants com restrições a gastos em investimento nos contratos de financiamento bancário. / The purpose of this study is to empirically verify the implications of corporate diversification, through coinsurance effect, in corporate finance and investment through two specific channels: the cost of bank borrowing and the likelihood of covenants with investment restrictions. To achieve this goal, this study estimated two models that control the endogeneity of the diversification decision by using an instrumental variables approach. The results do not show evidences that corporate diversification affects the cost of bank borrowing. In addition, the analysis suggests that corporate diversification reduces the likelihood of covenants with investment restrictions in bank borrowing contracts. Although the evidence is weak, it brings a new insight into how corporate diversification affects corporate results.

La diversité génétique des arbres tropicaux exploités pour leur bois est potentiellement menacée. Pourtant les mécanismes à l’origine de la distribution et de l’organisation de cette diversité génétique sont encore mal connus, notamment en Afrique. Parmi les hypothèses évoquées pour expliquer les patrons de diversité actuellement observés, l’hypothèse des refuges forestiers (liée aux changements climatiques du Tertiaire et du Quaternaire) est souvent la plus testée. Cependant, l’histoire commune des espèces forestières n’est pas toujours en accord avec les patrons phylogéographiques observés entre les espèces. Les différences de traits d'histoire de vie entre espèces, notamment leurs capacités de dispersion, pourraient influencer fortement la réponse des espèces aux changements environnementaux. La présente thèse ambitionne ainsi de caractériser le tempo de diversification des arbres des forêts tropicales africaines en relation avec les variations paléo-environnementales et d’évaluer l’impact éventuel de ces variations sur l’organisation de la diversité génétique au sein des populations. Elle ambitionne également de caractériser le système reproducteur et d’évaluer les capacités de dispersion des espèces en relation avec les pressions actuelles que subissent les forêts tropicales africaines.Afin d’atteindre ces objectifs, nous avons utilisé le genre Entandrophragma CDC (Meliaceae) qui compte une dizaine d’espèces distribuées des forêts humides guinéo-congolaises d’Afrique Centrale et de l’Ouest (E. angolense, E. cylindricum, E. candollei, E. utile, E. palustre), aux forêts humides des régions montagneuses d’Afrique de l’Est (E. excelsum), en passant par les forêts sèches des régions zambéziennes (E. bussei, E. caudatum, E. delevoyi, E. spicatum). Morphologiquement bien délimitées à l’exception de E. congoense parfois mis en synonymie avec E. angolense, les espèces forestières de ce genre sont caractérisées par la qualité de leur bois, qualité à l’origine de fortes pressions d’exploitation.Les relations phylogénétiques entre les espèces, basées sur le séquençage du génome chloroplastique complet et du ADN ribosomique confirment taxonomie actuelle (espèces généralement monophylétiques), et les délimitations au sein du genre à partir des caractères morphologiques (fleurs et fruits). Deux périodes majeures de diversification ont été inférées :au début du Miocène pour les sections et de la fin du Miocène au Pléistocène pour les espèces au sein des sections. La phylogénie montre trois transitions entre biomes, deux des forêts humides vers les forêts sèches et une vers les forêts de montagnes. Les phylogénies multi-marqueurs montrent également que E. congoense se distingue bien de E. angolense, ce qui a été confirmé par le génotypage de microsatellites nucléaires, mettant en évidence deux clusters génétiques correspondant aux espèces attendues. Chez les espèces des forêts tropicales humides, l’analyse comparative de l’organisation de la diversité génétique intraspécifique a permis de mettre en évidence le rôle de la trouée du Dahomey et de la ligne volcanique du Cameroun comme principales barrières aux flux de gènes entre l’Afrique de l’Ouest et l’Afrique Centrale. Cependant, nous observons une faible différentiation génétique au sein des forêts d’Afrique Centrale, avec aux plus deux clusters génétiques définis chez E. angolense et E. cylindricum et aucune congruence avec les zones traditionnellement proposées comme candidates de refuges forestiers. Cette faible différentiation serait probablement liée à des flux de gènes à longue distance observés chez ces espèces d’Entandrophragma.L’étude de la dispersion des graines et du pollen par analyses de parenté chez quatre espèces exploitées d’Entandrophragma (E. angolense, E. candollei, E. cylindricum, E. utile) révèle des événements de dispersion à longues distances (> 1000 m), associés à un système de reproduction principalement allogame (taux d’autofécondation < 10 %). Ces traits suggèrent que des arbres relativement isolés suite à l’exploitation sélective d’un peuplement forestier ne devraient pas rencontrer de problèmes de fertilité. Toutefois, l’analyse de la variation du succès reproducteur montre un pic de reproduction pour les arbres dont le diamètre à hauteur de poitrine est élevé et généralement supérieur au diamètre minimum d’exploitation (DME), ce qui peut affecter fortement le potentiel reproducteur d’un peuplement exploité. Ces résultats suggèrent que le DME devrait être augmenté en République du Congo afin d’assurer une gestion durable de la ressource.Cette thèse représente donc une contribution à la compréhension des processus évolutifs à l’origine de la diversité génétique des espèces forestières tropicales africaines. Elle fournit via l’analyse des flux de gènes, une contribution significative pour appréhender le devenir des populations d’arbres exploitées et favoriser une exploitation durable des ressources forestières. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Thesis (M.S.)--Massachusetts Institute of Technology, Alfred P. Sloan School of Management, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY. / Bibliography: leaves 336-339. / by Josephine S. Jimenez. / M.S.

O objetivo desse trabalho foi investigar os efeitos da quantidade de elementos manipulados na prática variada aleatória, após a prática constante, no processo adaptativo de aprendizagem motora. Participaram do estudo 66 crianças de ambos os gêneros e a tarefa foi de timing coincidente. Foram realizados três experimentos que diferiram no aspecto da tarefa manipulado na prática variada aleatória: velocidade do estímulo visual (experimento 1), padrão seqüencial de resposta (experimento 2) e velocidade do estímulo visual e padrão seqüencial de resposta conjuntamente (experimento 3). Em todos os experimentos, o delineamento envolveu duas quantidades de elementos: três e seis (experimentos 1 e 2); e, nove e trinta e seis (experimento 3). Fez parte do delineamento, também, duas fases de aprendizagem (estabilização e adaptação). As variáveis dependentes foram os erros absoluto, variável, constante e de execução. Os resultados dos três experimentos permitiram concluir que os efeitos das diferentes quantidades de variabilidade na prática aleatória, após a prática constante, no processo adaptativo de aprendizagem motora foram semelhantes / The objective of this work was to investigate the effect of the amount of elements manipulated in random practice, after the constant practice, in the adaptive process in motor learning. Participants were 66 children of both gender and the task was of coincident timing. Three experiments were carried out manipulating the task aspects in the random practice: visual stimulus speed (experiment 1); sequential response pattern (experiment 2); and visual stimulus speed and sequential response pattern simultaneously (experiment 3). In all experiments the design involved two amounts of elements manipulated in random practice: three and six (experiments 1 and 2), nine and thirty six (experiment 3). The design also involved two phases: stabilization and adaptation. The dependent variables were the absolute, variable, constant and execution error. The results of the three experiments allowed concluding that the effects of different quantities of variability in the random practice, after constant practice, in the adaptive process of motor learning were similar

This research evaluates the change observed during the implementation of an outsourced application development within a large defence organisation in Europe. Whereas most extant research focuses on the firm level or dyadic relations this research aims to uncover how different outcomes can be explained by attending to the micro-processes and specific mechanisms of work between purposive actors as they create the new service. The research was a longitudinal, six-year in-depth participant observation focused on the implementation of an HRM application carried out by six case organisations within a consortium formed to implement the service. The results of the field study are based on a grounded analysis from semi-structured interviews, focus groups, documents, and over 5,000 email communications involving a total of 62 stakeholders. A conceptual framework of neo-institutional theory, practice and power was used to analyse the process of change as the consortium worked together to deliver the outsourcing. The findings showed that political goals and behaviour influenced and shaped the outsourcing implementation and exposed the systemic nature of conflict within a constrained project context. The high conflict observed was shown to negatively influence success and supports the notion that strong contracting is only effective in stable contexts. It was also shown that tight control can negatively impact collaboration, by reducing adaptability, forcing vendors to take an inflexible posture. This type of behaviour was observed to increase power and conflict within the project and buyers reacted by increasing control and applying sanctions. This resulting in increased conflict and was a form of feedback loop. The findings also showed control in general is ineffective and can be overwhelmed in situations where there is high demand uncertainty. These observations add to the outsourcing and power/political literature by showing the central role of power and conflict and suggests the final configuration of an outsourcing is a negotiated order that may be at variance to the original objectives. Implications for practice: From a practical perspective, managers should think carefully before rushing into tight preventative contracts and consider the complexity of the demanded service and degree of completeness in their requirements. High uncertainty can lead to outsourcing failure, conflict within the implementation, and unmet expectations, unless specific mechanisms are in place to mitigate this. Furthermore, embedding new work processes and procedures to manage the service within the buying organisation is fundamental to how outsourcing actually works. Buyers and suppliers must pay attention to the design and implementation of processes and routines to manage effective delivery of the outsourced service.

To make the most of emergent techno-economic innovations, countries around the world must constantly upgrade their physical infrastructure and infrastructure systems – more than ever now that the world is facing growing environmental constraints. Public policies that foster the transformation of established infrastructure sectors, and encourage the development of new ones, can help to speed up and direct these structural changes. But to be effective, these policies must take into account how the process of development of new sectors varies among different infrastructure sectors, how it varies with respect to other kinds of sector, and how it varies in different institutional contexts. In this work, I show how three new infrastructure sectors developed in Chile, a ‘Hierarchical Market Economy' characterised by the dominance of diversified business groups and subsidiaries of multinational enterprises, a segmented labour market, and a low-skills equilibrium. These three sectors are the ones that first started to build wind farms, solar PV systems, and anaerobic digesters in the country, and in the study I characterize three aspects of their development process: a) the economic changes that turned these new (to the country) kinds of infrastructure facilities into attractive entrepreneurial opportunities; b) the economic agents that discovered these opportunities and developed them into viable investment projects, and those that sponsored and procured finance to build these projects; and c) the means by which these economic agents became capable of undertaking the relatively novel activities that their entrepreneurial initiative demanded. The resulting rich description of new sectoral development processes in Hierarchical Market Economies helps to understand what makes these processes vary inter-sectorally, cross-sectorally, and cross-nationally.

DeMiguel, Garlappi e Uppal (2009) fizeram a comparação da regra 1/N ou de Talmud com 14 modelos de otimização que vieram depois do trabalho de Markowitz (1952). As conclusões mostraram que todos os modelos de alocação ótima analisados tiveram um desempenho inferior ao da regra de Talmud. Tu e Zhou (2011) propuseram uma combinação entre Markowitz e Talmud para que tal modelo superasse Talmud. Os resultados obtidos foram satisfatórios. A desconsideração dos eventos extremos (dependência assimétrica ou caudal) durante o processo de construção de carteiras poderá diminuir as habilidades dos gestores de ativos em reduzir o risco através da diversificação. A modelagem de cópulas sobre os retornos dos ativos nos permite calcular uma alternativa para medir a dependência dos ativos em eventos extremos através do índice de dependência caudal inferior. Hatherley e Alcock (2007) relataram que o modelo de Markowitz tende a subestimar as perdas potenciais que venham a ocorrer na presença de eventos extremos de mercado (crashes) para um determinado nível de retorno esperado. Verificamos se as estratégias com dependência caudal superaram Talmud, o modelo de Markowitz e o modelo de Tu e Zhou (2011) através da simulação de 1.000 carteiras com 3, 5, 10 e 20 ativos escolhidos ao acaso do índice DJIA no período de 03/1990 até 12/2012. Concluímos que os modelos de dependência caudal e o de Markowitz tiveram uma desempenho fora da amostra superior ao Talmud e ao modelo de Tu e Zhou (2011) para as carteiras com 3, 5, 10 e 20 ativos. A estratégia com dependência caudal superou Markowitz, em termos de retorno acumulado, em mais de 60% dos meses considerados em todas as análises. Os resultados apontam que a regra de Talmud deve ser descartada num contexto de construção de carteiras com ações frente à estratégia com dependência caudal. / DeMiguel, Garlappi and Uppal (2009) made a comparison of rule 1 / N or Talmud with most optimization techniques that followed the work of Markowitz (1952). The conclusions were devastating for all asset allocation models in the context of portfolios combined with other portfolios. Tu and Zhou (2011) proposed a combination between Markowitz and Talmud to overcome such a rule Talmud. The results were satisfactory. In the presence of extreme events, the Pearson correlation coefficient tends to increase in magnitude, making spurious results diversification based solely on this factor. The elimination of extreme events (asymmetric or tail dependence) during the portfolio construction process can reduce the skills of asset managers to reduce risk through diversification. The copula theory allows us to calculate an alternative to measure the dependence of extreme events in assets through the index lower tail dependence. Hatherley and Alcock (2007) reported that the Markowitz model tends to underestimate the potential losses that may occur in the presence of extreme market events (crashes) for a given level of expected return. We check that the strategies with tail dependence overcame Talmud rule, the Markowitz model and the model of Tu and Zhou (2011) by simulating 1,000 portfolios with 3, 5, 10 and 20 randomly selected assets from DJIA for the period 03/1990 until 12/2012. We conclude that models of tail dependence and Markowitz had more performance ex-ante than Talmud and the Tu and Zhou (2011) model for portfolios with 3, 5, 10 and 20 assets. Tail dependence models overcome Markowitz, in terms of cumulative return, in over 60% of months considered in the analysis. The results indicate that the Talmud rule should be discarded in a context of constructing portfolios with individual stocks ahead strategies with tail dependence.

Cette thèse porte sur les relations franco-algériennes en matière d’hydrocarbure pendant la période 1962-1971. Huit ans après le début de la guerre, l’Algérie accède à l’indépendance. Le pétrole saharien, une des raisons du prolongement du conflit, appartient désormais à la jeune nation. Toutefois, les sociétés pétrolières françaises qui disposent d’un quasi-monopole sur l’industrie des hydrocarbures sauvegardent leurs nombreux avantages accordés à l’époque coloniale. Or, les accords d’Évian de mars 1962 qui garantissent aux sociétés françaises ces avantages sont remis en cause par les dirigeants du Front de libération nationale réunis en congrès quelques mois plus tard à Tripoli. En effet, la nationalisation des hydrocarbures figure parmi les objectifs du parti au pouvoir. L’adoption de la voie socialiste et le départ de la majorité de la population européenne d’Algérie compromettent la stratégie française qui vise à sauvegarder le plus longtemps possible une source de pétrole payable en franc. La thèse répond à la question suivante : quelles stratégies la France va-t- elle adopter pour réussir sa politique de désengagement progressif ? Pour répondre à cette problématique, cette recherche est fondée sur une démarche chronologique. Cette approche permet de mettre en valeur l’évolution des relations pétrolières franco-algériennes de 1962 à 1971. Les sources sont essentiellement les archives du groupe pétrolier TOTAL et celles du Quai d’Orsay. À ces documents qui nous renseignent sur le point de vue français s’ajoutent les archives personnelles du ministre algérien de l’Industrie et de l’Énergie, Belaïd Abdesselam. La thèse démontre qu’à partir du début des années 1960, l’objectif principal de la France est de diversifier ses sources d’approvisionnement et d’atténuer sa dépendance vis-à-vis de l’Algérie. Les ressources en provenance du Sahara sont donc destinées à servir ce projet. En outre, la thèse atteste que les sociétés pétrolières françaises s’investissent le moins possible en Algérie à partir de la seconde moitié des années 1960. Finalement, elle met en évidence les limites de la stratégie pétrolière française de diversification. / After an eight-year war, Algeria gained full independence. Saharan oil, a major reason for the extension of the war, became the property of the new independent republic. On the other hand, French petroleum companies, which had a quasi-monopoly over the oil industry, kept their former privileges. Nevertheless, the Evian Accords of March 1962, which guaranteed these privileges, were challenged by the new Algerian authorities meeting in Tripoli, Libya, a few months later. This was in line with the will of the Algerian governing party to nationalize the gas and oil industry. Finally the adoption of the socialist path by the new leadership, in addition to the departure of the majority of the European population, compromised the French strategy to keep control of Saharan supplies, the more so that they were payable in French francs. This thesis asks the following question: what strategies did France adopt to safeguard its interests in anticipation of the nationalization of the oil industry it considered inevitable? A chronological approach makes it possible to show the evolution of Franco-Algerian relation in the field of oil between 1962 and 1971. Sources are mainly the archives of the French petroleum company TOTAL and the French Foreign Affairs ministry. For the Algerian side, it makes uses of the personal archives of the Algerian minister of industry and energy at the time, Abdesselam Belaïd. The dissertation demonstrates that, starting from the beginning of 1960’s, the main goal of France was to diversify its sources of supply and to diminish its dependency towards Algerian oil. Saharan resources were part of the strategy. In addition, this research shows that, starting in the middle of the 1960’s, French petroleum companies diminished their level of engagement in Algeria to the minimum. Finally, the thesis highlights the limits of the French strategy of diversification of its oil supply.