Thesis (M.Sc.)--York University, 2004. Graduate Programme in Geography. / Typescript. Includes bibliographical references (leaves 196-210). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11810

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Thèse ou mémoire avec insertion d'articles / Le domaine médical a évolué drastiquement au cours des derniers siècles et la découverte du premier antibiotique, c'est-à-dire une substance qui est capable de détruire ou d'inactiver certains microorganismes, y a grandement contribué. Cette découverte a mené à une diminution du taux de mortalité causé par certaines bactéries pathogènes. Cependant, la commercialisation des antibiotiques a mené à une diversification des mécanismes de résistance par les bactéries. L'utilisation à large échelle des antibiotiques a favorisé l'émergence et le transfert de gènes de résistance aux antibiotiques (antibiotic resistance genes, ARGs) chez les bactéries. Cette résistance représente l'un des principaux enjeux de santé publique à l'échelle mondiale, en raison d'une recrudescence de maladies bactériennes qui ne répondent plus à ce traitement de première ligne. Cependant, on en sait très peu sur la dispersion des ARGs dans l'environnement et encore moins lorsqu'il s'agit de la distribution de ces gènes dans le Haut-Arctique, où les pressions climatiques risquent d'apporter plusieurs changements. L'objectif principal de ce projet est de caractériser, à l'aide d'approches métagénomiques, les ARGs des communautés microbiennes dans différents réservoirs environnementaux faisant partie d'un gradient d'influence anthropique en Arctique canadien, sur l'île de Cornwallis. Les objectifs spécifiques sont de caractériser les ARGs le long d'un continuum d'environnements influencés par l'humain (incluant un site impacté par des eaux usées) et de comparer leur distribution le long de ce gradient d'influence. Nous avons identifié des ARGs dans les tapis microbiens, l'eau du lac et les aérosols dans l'ensemble du bassin versant de Resolute Bay. Nous avons également constaté que les tapis microbiens de la région contaminée présentaient la plus grande diversité d'ARGs par rapport aux sites non contaminés. Bien que nous ayons identifiés les ARGs principalement dans les génomes bactériens, nos données suggèrent, pour la première fois, que certains virus géants sont capables d'héberger des ARGs. / The medical field has evolved dramatically over the last few centuries, and the discovery of the first antibiotic, a substance that can destroy or inactivate certain microorganisms, in 1928 was a major contributor. This discovery led to a decrease in the mortality rate caused by certain pathogenic bacteria. However, the commercialization of antibiotics has led to a diversification of various resistance mechanisms by bacteria. The widespread use of antibiotics has favored the emergence and transfer of antibiotic resistance genes (ARGs) in bacteria. Antibiotic resistance now represents one of the major global health crises due to an upsurge in bacterial-based diseases that no longer respond to this firstline treatment. However, very little is known about the dispersal of antibiotic resistance genes across different environments, and even less when it comes to the distribution of these genes in the High Arctic, where climate pressures are likely to increase the average temperature and disrupt existing microbial communities. The main objective of this project was to characterize, using metagenomic approaches, the ARGs of microbial communities in different environmental reservoirs along a gradient of anthropogenic influence in the Canadian Arctic on Cornwallis Island. The specific objectives were to characterize ARGs along a continuum of human-influenced environments (including sites impacted by sewage) and to compare their distribution along this gradient of anthropogenic influence. We identified ARGs in microbial mats, lake water and aerosols throughout the Resolute Bay watershed. We also found that microbial mats in the contaminated region had the highest diversity of ARGs relative to uncontaminated sites, and that this may be a remnant signal of the introduction of waste water. Although we identified ARGs predominantly in the genomes of bacteria, our data suggests, for the first time, that some giant viruses are capable of harbouring ARGs.

There are historically three main trends in understanding Wittgenstein's Tractatus. The first is the interpretation offered by the Vienna Circle. They read Wittgenstein as arguing that neither metaphysical nor normative propositions have any cognitive meaning, and thus are to be considered nonsense. This interpretation understands Wittgenstein as setting the limits of sense, and prescribing that nothing of substantive philosophical importance lies beyond that line. The second way of reading the Tractatus, which has became popular since the 1950s, is the interpretation which most currently accept as the early Wittgenstein's view; for this reason I refer to it as the 'standard reading.' According to this interpretation, Wittgenstein did not consider metaphysical and ethical discourse as nonsense. Rather, relying upon the distinction between saying [sagen] and showing [zeigen], he meant that these truths cannot be uttered, but instead are only shown. The standard reading can perhaps be best understood in contrast with the third interpretation, dubbed the "resolute reading." The resolute reading takes seriously Wittgenstein's remark at 6.54 that "[m]y propositions are elucidatory in this way: he who understands me finally recognizes them as nonsense [unsinnig]." According to the resolute interpretation, Wittgenstein is not advancing a series of philosophical theses in the Tractatus. Rejecting the distinction characteristic of standard readings, between propositions without sense [sinnlos] and just plain nonsense [unsinnig], these interpreters read Wittgenstein as treating ethical and metaphysical inquiry, as well as a bulk of the doctrines in the text, as nonsense. To them, Wittgenstein did not intend to put forth any theses in the the text. Instead his methodology is therapeutic, similar to the later philosophy. It In this essay I explain each interpretation, and evaluate them in terms of textual and philosophical viability. I conclude by arguing that the biases which exist in the tradition of analytic philosophy substantively temper the interpretation of historical texts, which ultimately leads to the fundamental distinction between these three interpretations.

Resolute Bay, a remote Arctic bay opening into Parry Channel, in the Canadian Arctic Archipelago, hosts diverse populations of marine mammals and fish at various times each year. These animals migrate through the bay following patterns linked to food availability and oceanographic conditions; however, these patterns are not well understood. The focus of this study was to measure the oceanographic properties of the waters in and around Resolute Bay and to record underwater sounds to obtain marine mammal temporal patterns and ambient sound levels. Results showed the water properties in Resolute Bay differed from the waters outside of the bay. Dissolved oxygen saturation levels in Resolute Bay decreased during ice-covered times, with lowest levels between May and July. Dissolved oxygen was replenished after the ice left the bay. Sudden changes in salinity, temperature, and dissolved oxygen were observed in Resolute Bay when outside waters entered. Mean third-octave band sound pressure levels were 85.3 dB re 1 μPa during high ice concentration, and 95.6 dB re 1 μPa during ice-free and freeze-up periods, and reached a maximum of 145.3 dB re 1 μPa when vessels were present. Belugas (Delphinapterus leucas) and narwhals (Monodon monocero) were only present in periods of low ice concentration, while bearded seals (Erignathus barbatus) and ringed seals (Pusa hispida) remained throughout the entire year. / Graduate / 2018-07-01

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