This dissertation considers the incommensurable interests of people, fossil capital, federal energy politics, and place in Northern Canada during the 1970s. By the late 1960s, the insatiable North American appetite for fossil fuels had turned its attention toward the Arctic region. After the discovery of rich deposits in Prudhoe Bay, Alaska, in 1968, largescale energy projects were proposed to access and exploit these Arctic natural resources. Canada participated in this northern oil rush; an exploration of oil and gas in the Arctic regions was accelerated in the early 1970s. The next challenge involved transporting the oil and gas to southern markets. In 1974, the Canadian federal government initiated the Mackenzie Valley Pipeline Inquiry to investigate the social, environmental, and economic effects of the pipeline routes proposed by a consortium of American and Canadian oil companies through the Mackenzie River Valley in the Northwest Territories where it would connect with existing pipeline infrastructure in northern Alberta. The Inquiry’s report recommended against immediate construction, encouraging instead a ten-year moratorium. Inquiry commissioner Thomas Berger’s report rationalized the delay to make time for settling Indigenous land claims in the region and for taking conservation measures to protect some key areas in the Mackenzie River Valley. In this dissertation, I examine how the discussion around pipeline construction shaped the meaning of the North, self-determination, and cultural recognition. In this dissertation, I particularly focus on how Indigenous peoples asserted their claims by rejecting state-driven policies and the interests of fossil-fuel capitalism in the North. / Thesis / Doctor of Philosophy (PhD) / Through the close reading of the Mackenzie Valley Pipeline Inquiry hearings, I examine how the discussion around energy development shaped the 1970s’ contentious Canadian politics of nation and North. Central to this debate, I focus on how Indigenous peoples asserted their land claims by challenging and refusing the settler state policies and the interests of fossil-fuel capitalism in the western Northwest Territories in the 1970s. By using the Inquiry process, northern Indigenous peoples challenged the idea that the state had a legitimate authority to decide and control the future or destiny of a territory or peoples in its defined borders.

Made available in DSpace on 2016-03-15T19:34:30Z (GMT). No. of bitstreams: 1 Edgard Padula.PDF: 1536698 bytes, checksum: dc410cd106bb57ea8fef14f926b3d02b (MD5) Previous issue date: 2007-08-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Legislative immunities were created to uphold the Legislative from pressures or threats, primarily by the Executive, as a means to provide more autonomy for the lawmakers to exercise their constitutional duties, such as debating and watching over the Administration which is the main reason for the governing system to be divided in three. For this reason we analyzed the most fail-safe doctrine addressing democracy, the General Theory of the State, the Legislative and political parties. We studied the theory of freedom from arrest and procedural immunity, as well as testimonial immunity and from incorporation to the Armed Forces, comparing the current system to the one in force prior to Constitutional Amendment 35/2001. We analyzed the institution at federal, state and municipal levels. We presented and analyzed the system of immunities in comparative law was submitted and analyzed vis-à-vis the laws of more relevant countries and those with greater proximity to Brazil, both in terms of geography as well as culture. We confronted countless laws, doctrine and case law. It is a fact that immunities were not conceived for the personal benefit of the legislative officers; however, corruption is not uncommon to the Legislative and the parties involved are not always punished accordingly. We measured how far immunities can lead to impunity. Amendment 35/2001 reduced the breadth of immunities, primarily of the procedural ones, which was successful in allowing the penal actions to continue against legislative officers. Hence, our investigation as to why corruption in the Legislative has not diminished. To answer this question, sociological study was made to try to grasp the reasons for Brazilians considerable lack of interest in politics and to understand politics twists and turns, despite my two decades of democratic experience. In the 2005/2006 biennium, various scandals of corruption were uncovered and repeatedly covered by the press, but did not result in very substantial sanctions. The average Brazilian citizen s behavior is far from civic, patriotic and gregarious. As a consequence, he/she does not closely watch over the lawmaking process, is not always concerned with strictly abiding by the laws or ensuring that others do the same, both in the public and private spheres. Citizens do not closely inspect the Parliament and the Administration as a whole. This detachment prevents citizens from understanding the nuances of politics and from pressing the government for results or behaviors, and consequently failing to demand punishment whenever it applies. In this scenario, we perceive that there is no Government for the people, and controlled by the people. Owing to considerable mismanagement of public moneys, the population is denied a more prosperous material life. It is noteworthy that legislative immunities are merely an aspect of many circumstances leading some politicians to show insignificant concern for ethics and legality, which defiles the image of the Legislative. The topic covered by this study stands out because it is current, relevant, complex and controversial, besides revealing a people who are needy of trustworthy and objective information, distant from parliament, and clearly inexperienced as to a citizen s duty. / As imunidades parlamentares existem para fortalecer o Legislativo de pressões ou ameaças, especialmente, por parte do Executivo, para que haja maior autonomia no exercício de seu múnus constitucional, como debater e fiscalizar a Administração, que é a principal finalidade do sistema de tripartição dos poderes. Desse modo, a mais avalizada doutrina sobre a democracia, Teoria Geral do Estado, Legislativo e partidos políticos foi analisada. Estudou-se a teoria das imunidades material e formal (freedom from arrest e processual), bem como a imunidade ao testemunho e incorporação às Forças Armadas, comparando o sistema atual ao anterior à Emenda Constitucional 35/2001. O instituto foi avaliado em níveis federal, estadual e municipal. O sistema das imunidades no direito comparado foi apresentado e analisado com a legislação dos países mais relevantes ou mais próximos do Brasil, tanto geográfica como culturalmente. Colacionou-se legislação, doutrina e jurisprudência. As imunidades não foram concebidas para desfrute pessoal dos parlamentares, mas não raro o Legislativo protagoniza casos de corrupção e nem sempre ocorre a punição dos envolvidos. Aferiu-se até que ponto as imunidades ensejam a impunidade. A Emenda 35/2001 reduziu o alcance das imunidades, sobretudo a processual, logrando êxito no sentido de possibilitar o andamento das ações penais contra parlamentares. Daí foi investigado por que a corrupção no Legislativo não foi reduzida. Para responder esta questão, foi realizado um estudo sociológico para tentar entender os motivos do brasileiro ter pouco interesse pela política e não compreender seus meandros, não obstante já possuir vinte anos de experiência democrática. No biênio 2005/2006, vários escândalos de corrupção foram desnudados e insistentemente alardeados pela mídia, mas as punições foram pífias. O cidadão brasileiro tem um comportamento pouco cívico, patriota e associativo. Não acompanha com afinco a feitura das leis, vezes não as observa nem zela para que sejam obedecidas, tanto em âmbito público como privado. Não fiscaliza de perto o parlamento e a Administração como um todo. Não apreende as coisas da política e sequer cobra resultados ou comportamentos, deixando de exigir punições, sempre que cabíveis. Com isso percebe-se que não existe um Governo para o povo, sob controle deste. Em razão do mau uso do dinheiro público, a população deixa de ter um padrão de vida material mais próspero. Observa-se que as imunidades parlamentares são um dos aspectos de toda uma miríade de circunstâncias, que leva alguns políticos a demonstrar pouca preocupação com a ética e a legalidade, o que deturpa a imagem do Legislativo. O tema do estudo destaca-se pela sua atualidade, relevância, complexidade e polêmica; além de mostrar uma população carente de informações confiáveis, objetivas e distante do parlamento, sendo inexperiente nas atribuições da cidadania.

This thesis is focused on an analysis of British-Canadian relations in 1921-1930, ie. mostly the first two terms of office of the Canadian Prime Minister William Lyon Mackenzie King, who significantly contributed to the change of relations of the oldest British dominion and his mother country. The thesis analyses the position of Canada towards Great Britain and the influence of the then British and Canadian government on the development of mutual relations, which have gone through important changes and led to the greater measure of Canadian independence in the chosen period. Specifically, the thesis will focus on the context of key international events, which had an impact on the British-Canadian relations: the Chanak crisis, the Halibut Treaty between Canada and the United States of America, the King-Byng affair (1926), the Imperial Conference of 1926 and the Canadian activity in the League of Nations.

Tableau d'honneur de la Faculté des études supérieures et postdoctorales, 2006-2007 / Les pergélisols nordiques contiennent une quantité significative de carbone organique. Or, son utilisation par les microorganismes dans les rivières et l’océan Arctique est peu connue. Au cours de l’Arctic River-Delta Experiment (ARDEX), des variables environnementales et microbiologiques furent mesurées le long d’un transect de 300 km entre le fleuve Mackenzie et la mer de Beaufort (juillet-août 2004). Nous voulions étudier les gradients fluviaux et estuariens de la structure et de l’activité de la communauté microbienne et évaluer l’influence des UV et de l’approvisionnement en carbone sur les processus bactériens. La communauté microbienne a changé le long du transect et les bactéries attachées aux particules jouaient un rôle majeur dans le fleuve et la zone de transition. Le métabolisme bactérien était limité par la disponibilité du carbone dans le fleuve Mackenzie. La photodégradation a augmenté la labilité du carbone organique dans le fleuve, mais l’a diminuée dans la mer de Beaufort. / Globally significant quantities of organic carbon are stored in northern permafrost soils, but little is known about how this carbon is processed by microbial communities once it enters rivers and is transported to the coastal Arctic Ocean. As part of the Arctic River-Delta Experiment (ARDEX), we measured environmental and microbiological variables along a 300 km transect across the Mackenzie River and coastal Beaufort Sea in July-August 2004 to investigate the river and estuarine gradients in microbial community structure and activity, and to evaluate the influence of UV exposure and carbon supply on bacterial processes in these ecosystems. Microbial community structure changed along the transect and the contribution of particle-attached bacteria was significantly higher in riverine and transition zone stations. Experimental results showed that bacterial metabolism was carbon limited in the Mackenzie River. Photodegradation increased organic carbon biolability in the Mackenzie River and decreased it in the Beaufort Sea.

Os arquitetos e urbanistas que colaram grau na Faculdade de Arquitetura e Urbanismo do atual Instituto Presbiteriano Mackenzie no início dos anos 80 exerceram sua profissão em um cenário de mudanças constantes. Desde sua colação de grau, no Brasil e no mundo surgiram fatores políticos, econômicos e tecnológicos que tiveram conseqüências nos planos profissional e pessoal, de toda a sociedade e na vida de cada um daqueles então recém-formados arquitetos. O objetivo desta pesquisa é conhecer agora, decorridos mais de 30 anos, quais foram esses fatores e suas influências, como essa geração de arquitetos e urbanistas enfrentou essa situação, como se saiu na profissão, que tipo de atividade desenvolveu e como está atualmente. / The architects and urbanists who graduated at the Architecture and Urbanism College at the current Mackenzie Presbyterian Institute in the early 80\'s exercised their profession in a constant changing environment. Since their graduation, in Brazil and in the world emerged political, economic and technological issues that must have had consequences in their professional and personal plans, in the whole society and in the life of each one of those then recently graduated architects. The objective of this research is to know now, after more than 30 years, what were these factors, their influence, and how did this generation of architects and urbanists managed to deal with this environment, how they practiced the profession, what kind of activity they developed and how are they doing nowadays.

Orientadora: Profa. Dra. Graciela de Souza Oliver / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ensino, História, Filosofia das Ciências e Matemática, 2014. / Esta pesquisa apresenta os meios pelos quais se deram as relações na institucionalização da Química no Brasil, tomando como caso o Mackenzie College e seus cursos nessa área. O Mackenzie College, denominação que antecedeu a atual Universidade Presbiteriana Mackenzie, tem suas raízes na vinda de missionários presbiterianos norteamericanos para o Brasil, iniciando a escola em 1870. A prosperidade da escola coincidiu com um período de valorização da atividade científica no país expressa na criação de várias instituições voltadas para a ciência e na reformulação das já existentes. A pesquisa buscou compreender o desenvolvimento inicial dos primeiros cursos de Química no Mackenzie College identificando as orientações científicas e o perfil do aluno formado. Os focos que orientaram este trabalho consistiram na identificação, neste curso, da desenvolvida química norte-americana do período, assim como a verificação de um ensino pragmático pautado na valorização dos desafios intelectuais e da prática do trabalho presentes na doutrina presbiteriana. De acordo com a atual historiografia, que propõe investigar o contexto histórico do desenvolvimento da ciência e, neste caso específico, da Química, avaliamos fontes primárias e secundárias procurando contextualizar o momento social, cultural, econômico e religioso que originou o referido projeto de ensino desta disciplina. / This research presents how the relations of the institutionalization of Chemistry happened in Brazil, using the case of Mackenzie College and its courses in this area. The Mackenzie College, nomination that preceded the current Presbyterian Mackenzie University, has its roots in the coming of Presbyterian North American missionaries to Brazil, who initiated the school in 1870. The prosperity of the school coincided with a period of appreciation of the scientific activity in the country, expressed in the creation of several scientific institutions and also the reformulation of existent ones. The aim of the research was to understand the initial development of the Chemistry Courses at The Mackenzie College, identifying the scientific orientations and the profile of the graduate student. The focus that guided this paper consisted in identifying the developed North American Chemistry in that period, as well as the verification of a pragmatic teaching, based on the intellectual challenges and the practice of the work present in the Presbyterian doctrine. According to the current historiography, which aims at investigating the historical context of the development of science and, in this specific case, of Chemistry, we assessed the primary and secondary sources, contextualizing the social, cultural, economic and religious period that originated the referred project of teaching this subject.

Os arquitetos e urbanistas que colaram grau na Faculdade de Arquitetura e Urbanismo do atual Instituto Presbiteriano Mackenzie no início dos anos 80 exerceram sua profissão em um cenário de mudanças constantes. Desde sua colação de grau, no Brasil e no mundo surgiram fatores políticos, econômicos e tecnológicos que tiveram conseqüências nos planos profissional e pessoal, de toda a sociedade e na vida de cada um daqueles então recém-formados arquitetos. O objetivo desta pesquisa é conhecer agora, decorridos mais de 30 anos, quais foram esses fatores e suas influências, como essa geração de arquitetos e urbanistas enfrentou essa situação, como se saiu na profissão, que tipo de atividade desenvolveu e como está atualmente. / The architects and urbanists who graduated at the Architecture and Urbanism College at the current Mackenzie Presbyterian Institute in the early 80\'s exercised their profession in a constant changing environment. Since their graduation, in Brazil and in the world emerged political, economic and technological issues that must have had consequences in their professional and personal plans, in the whole society and in the life of each one of those then recently graduated architects. The objective of this research is to know now, after more than 30 years, what were these factors, their influence, and how did this generation of architects and urbanists managed to deal with this environment, how they practiced the profession, what kind of activity they developed and how are they doing nowadays.

The ecosystem of the high northern latitudes is affected by the recently changing environmental conditions. The Arctic has undergone a significant climatic change over the last decades. The land coverage is changing and a phenological response to the warming is apparent. Remotely sensed data can assist the monitoring and quantification of these changes. The remote sensing of the Arctic was predominantly carried out by the usage of optical sensors but these encounter problems in the Arctic environment, e.g. the frequent cloud cover or the solar geometry. In contrast, the imaging of Synthetic Aperture Radar is not affected by the cloud cover and the acquisition of radar imagery is independent of the solar illumination. The objective of this work was to explore how polarimetric Synthetic Aperture Radar (PolSAR) data of TerraSAR-X, TanDEM-X, Radarsat-2 and ALOS PALSAR and interferometric-derived digital elevation model data of the TanDEM-X Mission can contribute to collect meaningful information on the actual state of the Arctic Environment. The study was conducted for Canadian sites of the Mackenzie Delta Region and Banks Island and in situ reference data were available for the assessment. The up-to-date analysis of the PolSAR data made the application of the Non-Local Means filtering and of the decomposition of co-polarized data necessary. The Non-Local Means filter showed a high capability to preserve the image values, to keep the edges and to reduce the speckle. This supported not only the suitability for the interpretation but also for the classification. The classification accuracies of Non-Local Means filtered data were in average +10% higher compared to unfiltered images. The correlation of the co- and quad-polarized decomposition features was high for classes with distinct surface or double bounce scattering and a usage of the co-polarized data is beneficial for regions of natural land coverage and for low vegetation formations with little volume scattering. The evaluation further revealed that the X- and C-Band were most sensitive to the generalized land cover classes. It was found that the X-Band data were sensitive to low vegetation formations with low shrub density, the C-Band data were sensitive to the shrub density and the shrub dominated tundra. In contrast, the L-Band data were less sensitive to the land cover. Among the different dual-polarized data the HH/VV-polarized data were identified to be most meaningful for the characterization and classification, followed by the HH/HV-polarized and the VV/VH-polarized data. The quad-polarized data showed highest sensitivity to the land cover but differences to the co-polarized data were small. The accuracy assessment showed that spectral information was required for accurate land cover classification. The best results were obtained when spectral and radar information was combined. The benefit of including radar data in the classification was up to +15% accuracy and most significant for the classes wetland and sparse vegetated tundra. The best classifications were realized with quad-polarized C-Band and multispectral data and with co-polarized X-Band and multispectral data. The overall accuracy was up to 80% for unsupervised and up to 90% for supervised classifications. The results indicated that the shortwave co-polarized data show promise for the classification of tundra land cover since the polarimetric information is sensitive to low vegetation and the wetlands. Furthermore, co-polarized data provide a higher spatial resolution than the quad-polarized data. The analysis of the intermediate digital elevation model data of the TanDEM-X showed a high potential for the characterization of the surface morphology. The basic and relative topographic features were shown to be of high relevance for the quantification of the surface morphology and an area-wide application is feasible. In addition, these data were of value for the classification and delineation of landforms. Such classifications will assist the delineation of geomorphological units and have potential to identify locations of actual and future morphologic activity. / Die polaren Regionen der Erde zeigen eine hohe Sensitivität gegenüber dem aktuell stattfindenden klimatischen Wandel. Für den Raum der Arktis wurde eine signifikante Erwärmung der Landoberfläche beobachtet und zukünftige Prognosen zeigen einen positiven Trend der Temperaturentwicklung. Die Folgen für das System sind tiefgehend, zahlreich und zeigen sich bereits heute - beispielsweise in einer Zunahme der photosynthetischen Aktivität und einer Verstärkung der geomorphologischen Dynamik. Durch satellitengestützte Fernerkundungssysteme steht ein Instrumentarium bereit, welches in der Lage ist, solch großflächigen und aktuellen Änderungen der Landoberfläche nachzuzeichnen und zu quantifizieren. Insbesondere optische Systeme haben in den vergangen Jahren ihre hohe Anwendbarkeit für die kontinuierliche Beobachtung und Quantifizierung von Änderungen bewiesen, bzw. durch sie ist ein Erkennen der Änderungen erst ermöglicht worden. Der Nutzen von optischen Systemen für die Beobachtung der arktischen Landoberfläche wird dabei aber durch die häufige Beschattung durch Wolken und die Beleuchtungsgeometrie erschwert, bzw. unmöglich gemacht. Demgegenüber eröffnen bildgebende Radarsystem durch die aktive Sendung von elektromagnetischen Signalen die Möglichkeit kontinuierlich Daten über den Zustand der Oberfläche aufzuzeichnen, ohne von den atmosphärischen oder orbitalen Bedingungen abhängig zu sein. Das Ziel der vorliegenden Arbeit war es den Nutzen und Mehrwert von polarimetrischen Synthetic Aperture Radar (PolSAR) Daten der Satelliten TerraSAR-X, TanDEM-X, Radarsat-2 und ALOS PALSAR für die Charakterisierung und Klassifikation der arktischen Landoberfläche zu identifizieren. Darüber hinaus war es ein Ziel das vorläufige interferometrische digitale Höhenmodel der TanDEM-X Mission für die Charakterisierung der Landoberflächen-Morphologie zu verwenden. Die Arbeiten erfolgten hauptsächlich an ausgewählten Testgebieten im Bereich des kanadischen Mackenzie Deltas und im Norden von Banks Islanld. Für diese Regionen standen in situ erhobene Referenzdaten zur Landbedeckung zur Verfügung. Mit Blick auf den aktuellen Stand der Forschung wurden die Radardaten mit einem entwickelten Non-Local-Means Verfahren gefiltert. Die co-polarisierten Daten wurde zudem mit einer neu entwickelten zwei Komponenten Dekomposition verarbeitet. Das entwickelte Filterverfahren zeigt eine hohe Anwendbarkeit für alle Radardaten. Der Ansatz war in der Lage die Kanten und Grauwerte im Bild zu erhalten, bei einer gleichzeitigen Reduktion der Varianz und des Speckle-Effekts. Dies verbesserte nicht nur die Bildinterpretation, sondern auch die Bildklassifikation und eine Erhöhung der Klassifikationsgüte von ca. +10% konnte durch die Filterung erreicht werden. Die Merkmale der Dekomposition von co-polarisierten Daten zeigten eine hohe Korrelation zu den entsprechenden Merkmalen der Dekomposition von voll-polarisierten Daten. Die Korrelation war besonders hoch für Landbedeckungstypen, welche eine double oder single bounce Rückstreuung hervorrufen. Eine Anwendung von co-polarisierten Daten ist somit besonders sinnvoll und aussagekräftig für Landbedeckungstypen, welche nur einen geringen Teil an Volumenstreuung bedingen. Die vergleichende Auswertung der PolSAR Daten zeigte, dass sowohl X- als auch C-Band Daten besonders sensitiv für die untersuchten Landbedeckungsklassen waren. Die X-Band Daten zeigten die höchste Sensitivität für niedrige Tundrengesellschaften. Die C-Band Daten zeigten eine höhere Sensitivität für mittelhohe Tundrengesellschaften und Gebüsch (shrub). Die L-Band Daten wiesen im Vergleich dazu die geringste Sensitivität für die Oberflächenbedeckung auf. Ein Vergleich von verschiedenen dual-polarisierten Daten zeigte, dass die Kanalkombination HH/VV die beste Differenzierung der Landbedeckungsklassen lieferte. Weniger deutlich war die Differenzierung mit den Kombinationen HH/HV und VV/VH. Insgesamt am besten waren jedoch die voll-polarisierten Daten geeignet, auch wenn die Verbesserung im Vergleich zu den co-polarisierten Daten nur gering war. Die Analyse der Klassifikationsgenauigkeiten bestätigte dieses Bild, machte jedoch deutlich, dass zu einer genauen Landbedeckungsklassifikation die Einbeziehung von multispektraler Information notwendig ist. Eine Nutzung von voll-polarisierten C-Band und multispektralen Daten erbrachte so eine mittlere Güte von ca. 80% für unüberwachte und von ca. 90% für überwachte Klassifikationsverfahren. Ähnlich hohe Werte wurden für die Kombination von co-polarisierten X-Band und multispektralen Daten erreicht. Im Vergleich zu Klassifikation die nur auf Grundlage von multispektralen Daten durchgeführt wurden, erbrachte die Einbeziehung der polarisierten Radardaten eine zusätzliche durchschnittliche Klassifikationsgüte von ca. +15%. Der Zugewinn und die Möglichkeit zur Differenzierung war vor allem für die Bedeckungstypen der Feuchtgebiete (wetlands) und der niedrigen Tundrengesellschaften festzustellen. Die Analyse der digitalen Höhenmodelle zeigte ein hohes Potential der TanDEM-X Daten für die Charakterisierung der topographischen Gegebenheiten. Die aus den Daten abgeleiteten absoluten und relativen topographischen Merkmale waren für eine morphometrische Quantifizierung der Landoberflächen-Morphologie geeignet. Zudem konnten diese Merkmale auch für eine initiale Klassifikation der Landformen genutzt werden. Die Daten zeigten somit ein hohes Potential für die Unterstützung der geomorphologischen Kartierung und für die Identifizierung der aktuellen und zukünftigen Dynamik der Landoberfläche.

La photohétérotrophie est la capacité d'utiliser des substrats organiques et de capturer l'énergie lumineuse. Elle est pratiquée par les bactéries phototrophes anoxygéniques aérobies (BPAA), les bactéries contenant de la protéorhodopsine (BPR) et les picocyanobactéries (Synechococcus). Les augmentations de l'export fluvial de carbone organique et de l'exposition de l'océan aux radiations solaires s'intensifient en Arctique, rendant cette région intéressante pour étudier la place des photohétérotrophes dans l'utilisation du carbone et de la lumière. Par l'utilisation de multiples approches de quantification absolue, de diversité culturale et moléculaire, notre étude est la première à caractériser à haute résolution les photohétérotrophes dans l'Océan Arctique. Les picocyanobactéries n'ont été détectées que dans l'estuaire du Mackenzie alors que BPAA et B-PR étaient présentes en mer de Beaufort. La communauté PAA était liée aux apports fluviaux contrairement à celle des B-PR principalement oligotrophe. Les distributions de ces communautés présentaient des patrons différents de celles du bactérioplancton suggérant un avantage écologique de la photohétérotrophie dans ces eaux. La communauté PAA était dominée par un clade nouveau de Betaproteobacteria et par les Rhodobacterales. Les Alphaproteobacteria, notamment des SAR11 et des clades endémiques de SAR116, dominaient la communauté de BPR. La majorité des BPR exprimait activement la PR suggérant de potentiels bénéfices. L'ensemble de nos résultats montre que la photohétérotrophie est répandue dans l'Océan Arctique et suggère que son rôle pourrait être différent en fonction des conditions environnementales rencontrées.

In Canada’s western Arctic, perennial discharge from permafrost watersheds is the surface manifestation of active groundwater flow systems, yet understanding the mechanisms of groundwater recharge and flow in periglacial environments remains enigmatic. This thesis addresses questions on how and where groundwater recharge occurs. Watersheds were selected in Yukon (Fishing Branch River at Bear Cave Mountain) and the Northwest Territories at latitudes spanning from continuous to discontinuous permafrost (five tributary rivers to the Mackenzie River from Wrigley to Aklavik). All are characterized by perennial flow with open water in the winter, and discharge from sedimentary formations of karstic carbonates and evaporate rocks. Determinations of groundwater contributions to discharge, mixing, recharge conditions and circulation times were made on the basis of a suite of analytical approaches involving measurements of major dissolved ions, δ18O, δD, δ13CDIC, 3H, noble gases and flow gauging was conducted at some sites. The application of these tracers show that hydrogeological conditions and flow paths in permafrost terrains are surprisingly similar to those of temperate regions. Groundwater recharge was determined to be a mix of annual precipitation with contributions from snowmelt and precipitation. All systems investigated show that groundwaters have recharged through organic soils with elevated PCO2, which suggests that recharge occurs largely during summer when biological activity is high. Noble gas concentrations show that the recharge temperature was between 0 and 6 °C, which, when considered in the context of discharge temperatures, suggests that there is no significant imbalance of energy flux into the subsurface. Groundwater ages were found using the 3H-3He method and were dependent on flow path. By characterizing groundwater and surface water chemistry, the proportion of groundwater was found in numerous water courses. The possible impact of ground ice formation and melting on noble gas concentrations in groundwater was considered. To assess this link, a new method to measure the noble gas composition of ground ice bodies was developed. The method can be used to determine the origin of ice, based on changes in noble gas ratios between ice originating from compaction of snow (e.g. glacier ice) vs. ice originating from freezing of water. No significant fractionation of noble gases during groundwater freezing and ground ice formation was identified. Applied to determination of the origin of ground ice bodies, the method was shown to be both diagnostic of ice origin and un-encumbered by reactivity in the subsurface, which compromises the use of the dominant atmospheric gases (O2 and N2).   Résumé Dans l’Ouest de l'Arctique canadien, la décharge pérenne dans certaines rivières en région de pergélisol est la manifestation en surface d’une circulation d’eau souterraine; cependant la compréhension des mécanismes d’écoulement et de recharge des eaux souterraines en région de pergélisol demeure énigmatique. Cette thèse s’intéresse à la question de savoir comment et où la recharge des eaux souterraines se produit. Des bassins versants ont été choisis au Yukon (Rivière Fishing Branch à Bear Cave Mountain) et dans les Territoire du Nord-Ouest à des latitudes s’étendant du pergélisol discontinu au pergélisol continu (cinq tributaires du Mackenzie entre Wrigley et Aklavik). Toutes ces rivières ont un écoulement d’eau pérenne avec des zones non gelées et une décharge dans des formations sédimentaires de roches carbonatées et d‘évaporites. L’identification des contributions des eaux à la décharge, les mélanges, les conditions de recharge, et les temps de circulation ont été faits à partir d’analyses qui ont inclus les concentrations en éléments majeurs, leur valeur isotopique (δ18O, δD, δ13C, 3H), ainsi que leur teneur en gaz rares. A certain des sites analysés des mesures d’écoulement ont été prises. L’application de ces traceurs montre que les conditions hydrauliques et le chemin des écoulements en région de pergélisol sont similaires à ceux des régions tempérées. La recharge en eau souterraine a été identifiée comme étant un mélange de précipitations annuelles, avec des contributions de neige et de pluies. Tous les systèmes étudiés montrent que les eaux souterraines se sont rechargées en traversant des sols organiques avec une PCO2 élevée, ce qui suggère que la recharge se produire largement durant l’été quand l’activité biologique est élevée. Cependant, les concentrations en gaz nobles montre que la température de recharge des eaux souterraines était entre 0 et 6 °C ce qui indique qu’il n’y a pas de déséquilibre de flux d’énergie à l’intérieur de la zone proche de la surface. L’âge des eaux a été déterminé par la méthode 3H-3He et cet âge est dépendant du chemin d'écoulement. En caractérisant les paramètres chimiques des eaux de surface et des eaux souterraines, il a été possible de trouver la contribution des eaux souterraines aux eaux surface. Le possible impact de la formation et de la fonte de la glace souterraine sur les concentrations des gaz nobles a été considéré. Pour déterminer s’il y a un lien entre ceux-ci, une nouvelle méthode pour mesurer la concentration en gaz nobles dans les glaces souterraines a été développée. La méthode peut être utilisée pour déterminer l’origine de la glace; elle est basée sur les changements dans les rapports des gaz nobles entre la glace issue de la compaction de la neige (c’est-à-dire la glace de glacier) par opposition à la glace issue du gel de l’eau. Aucun fractionnement significatif des gaz nobles durant l’engel des eaux souterraines et la formation de glaces souterraines n’a été identifié. Appliquée à l’identification de l’origine des masses de glace enfouies, on a montré que la méthode pouvait permettre d’identifier l’origine des glaces souterraines sans qu’elle soit affectée par des réactions biologiques de sub-surface, lesquelles rendent inutilisables les gaz atmosphériques (O2, and N2).