Human-caused ecological change negatively affects the sustainability of many wildlife populations but may be especially challenging for large carnivores and ungulates. Long-term physiological stress may be an important mechanism linking ecological change with impaired health and reduced population performance in these groups. The determination of hair cortisol concentration (HCC) has recently demonstrated potential as a biomarker of long-term stress in humans and domestic animals, and may also represent a practical technique for use in free-ranging wildlife. The objectives of this research program were to: 1) develop and apply an accurate and reliable method for measuring cortisol levels in hair collected opportunistically or remotely from free-ranging grizzly bears (Ursus arctos), polar bears (Ursus maritimus), and caribou (Rangifer tarandus sp.), and 2) to evaluate the utility of HCC as a biomarker of long-term stress (and thus potentially useful conservation tool) in these threatened species. An enzyme-immunoassay (EIA) based technique for measuring HCC in non-human primates was successfully modified for use with small quantities (5-100 mg) of hair representative of samples which may be obtained through opportunistic (e.g. hunting, research captures, archives) or remote (e.g. barb wire snagging) methods in each species. HCC was determined in 151 free-ranging grizzly bears from Alberta, Canada (mean 2.84 pg/mg, range 0.62-43.33 pg/mg); 185 free-ranging polar bears from southern Hudson Bay, Canada (mean 0.48 pg/mg range, 0.16-2.26 pg/mg); in 12 captive Alaskan caribou (R. t. granti) (mean 2.31 pg/mg, range, 1.57-3.86 pg/mg) and 12 captive reindeer (R .t. tarandus) (mean 2.88 pg/mg, range 2.21-3.40 pg/mg) injected either with adrenocorticotropic hormone (ACTH) or saline; and in 94 free-ranging caribou (R. t. groenlandicus) from West Greenland (mean 2.21 pg/mg, range 0.60-6.90 pg/mg). Factors influencing HCC in each species were then explored including: 1) technical considerations for the prudent use of HCC analysis and 2) potential relationships between HCC, biological traits, health, and prevailing environmental conditions. Evidence revealed in this study suggests that, with further research, this technique may show potential as a practical conservation tool for use in free-ranging grizzly bear, polar bear, and caribou populations.

This thesis has two major objectives. The first objective is to investigate the seasonal and diurnal variations in occurrence of HF coherent echoes. We assess F-region echo occurrence rates for the PolarDARN HF radars at Inuvik (INV) and Rankin Inlet (RKN) and the auroral zone SuperDARN radars at Saskatoon (SAS) and Prince George (PGR) for the period of 2007-2010. We show that the INV and RKN PolarDARN radars show comparable rates of echo occurrence all the time and they detect 1.5-2.5 times more echoes through ½-hop propagation mode (MLATs=80°-85°) than the SAS and PGR SuperDARN radars through 1½-hope propagation mode (MLATs=75°-80°). For all four radars, the winter occurrence rates are about ~2 times higher than the summer rates. For observations in the dusk, midnight and dawn sectors, equinoctial maxima are evident. The pattern of echo occurrence in terms of MLT/season is about the same for all radars with clear maxima near noon during winters and summers and enhanced (as compared to other time of the day) occurrence rates during equinoctial dusk and dawn hours. Additionally, to investigate the effect of solar cycle on occurrence of F-region echoes, we consider the near noon and near midnight echo occurrence rates for the Saskatoon radar over the period of 1994-2010. We show that there is a strong, by a factor of ~10, increase in SAS night-side echo occurrence towards solar maximum. The effect does not exist for the dayside echoes; moreover, a decrease in number of echoes, by a factor of ~2, was discovered for the declining phase of the solar cycle. The second objective is to evaluate the electron density and the electric field as factors controlling the occurrence of F-region echoes. We use observations of these two ionospheric parameters measured by CADI ionosonde and RKN observations of echo occurrence rates over Resolute Bay (MLAT=83°). We show that there is a correlation in changes of echo occurrence and electron density changes for 3 years of radar-ionosonde joint operation (2008-2010). The comparison of radar-ionosonde data shows that the enhanced echo occurrence at near noon hours during summer months correlate with the enhanced electric field during these periods.

北極地區因蘊藏豐富之石油、天然氣、自然資源及煤、鐵、銅、鈾等礦產資源，加上因特殊地理位置決定其全球性戰略地位，引起美、俄、加、丹麥、挪威等北極國家與其他非北極國家之爭奪，尤其在全球油氣資源日趨匱乏的今天，被稱為「第二個中東」的北極價值日益顯現； 北極之於人類價值有四重—環境、軍事、資源和航道，而中共為維護其國家經濟生存命脈之北海航道航行權及全球戰略地位之維護，而積極參與北極事物之國際活動。 吾人乃針對中共參與北冰洋區域事務博弈之利弊得失等面向進行分析與探討，並發現當前中共面臨之障礙，包括北冰洋沿岸國家試圖阻撓非北冰洋沿岸國家進入北極地區、缺乏對中共有利的國際協調機制平臺、缺乏足夠的科研資訊儲備與冰海航運船舶等限制。 此外，吾人另對北極事務主要競逐國之積極作為進行分析，並提出中共未來應對北極事務可能採取之因應作為，包括加大利用現有國際法中有利條款，維護中共的北冰洋航運權益、提升中共對北極事務的制度性參與力度、積極維護北冰洋航道的公海航運自由等，作為中共爭奪北海權益之準備作為等結論。 　　同時，吾人認為中共將持續加大對北極區域事務關注力度、決不允許淪為他國之制約地位，而威脅自身經濟、安全地位之發展；尤其中共對北極海海域劃界問題之主張，具有成為未來中共於東海劃界問題與西南海域劃界問題之參考，實為我方關注要點。 當前，我國與中共的關係，雖有所緩和，但從大的戰略方向上，中共在國際上對臺灣仍持續加以打壓，孤立臺灣，因此對臺灣而言，須瞭解中共在國際戰略中的各種作為，包括對北極事務採取的戰略為何？才能有所因應。 / Because of the Arctic region is rich in oil, natural gas, and natural resources because of the special geographical position with its global strategic position, cause the United States, Russia, Canada, Denmark, Norway and other countries and other Arctic the Arctic National Competition, especially in the global oil and gas resources shortage today, polar value appears day by day; the Arctic on the human value of four heavy environment, military, resource and channel, and the Communist Party of China to maintain its national economy lifeblood of Beihai waterway navigation rights and the maintenance of global strategic position, and actively participate in international activities in the Arctic. It is aimed at China's participation in the Arctic region affairs the pros and cons of the game were analyzed and discussed, and found that the current CPC faced obstacles, including the Arctic coastal States trying to thwart the Arctic coastal states into the Arctic, the lack of the favorable international coordination mechanism, the lack of adequate scientific research platform information reserve and ice shipping limited. In addition, one another on the Arctic affairs mainly competing country actively as carries on the analysis, and proposed the future Arctic affairs may adopt coping as, including the increased use of existing international law the favourable terms, maintenance of Arctic shipping interests, enhance the north polar affairs system involved in active maintenance efforts, Arctic waterway the free shipping, as the battle for Beihai interests of the prepared as a conclusion. At the same time, we believe that China will continue to increase the intensity of concern, regional affairs must not be allowed to become his country's restrictive position, threatening its economic, safety status of development; especially on the Arctic sea delimitation of advocates, has become the future of Yu Donghai and southwest of delimitation of maritime boundary delimitation of reference, it is for me square key points. At present, China's relations with the CPC, although alleviate somewhat, but from the strategic direction of the Communist Party of China in international, Taiwan continued to be suppressed, isolated Taiwan, so in the case of Taiwan, must understand China in international strategy in various as, including the Arctic affairs strategy? To help with.

La transferencia nuclear de células somáticas (SCNT) en la especie porcina se ha convertido en una herramienta muy útil para para la elaboración de modelos genéticos de enfermedades humanas y para el uso en xenotransplantes. Aunque el número de cerdos clonados aumenta cada año, la eficiencia total de esta tecnología es todavía muy baja. Uno de los pasos más difíciles de la SCNT en porcino es la enucleación del ovocito, principalmente debido a que su citoplasma contiene numerosas gotas lipídicas. El principal objetivo de la tesis fue evaluar el efecto de diversas técnicas para visualizar la placa metafásica y el corpúsculo polar sobre la capacidad de desarrollo de ovocitos porcinos madurados in vitro. / Somatic cell nuclear transfer (SCNT) technology in porcine has become a very useful tool for the elaboration of genetic models for human diseases and the use in xenotransplantation. The efficiency of SCNT is still very low, although the number of cloned pigs increases each year. One of the hardest steps of porcine SCNT is the enucleation of the oocyte because its cytoplasm contains many lipid droplets. The main objective of this thesis was to assess the effect of several approaches to visualize the metaphase II plate and the first polar body on the developmental ability of in vitro mature porcine oocytes.

The goal of the project work has been to study the symmetry of the phonons in 4H and 6H-SiC for different measuring geometries by using two experimental techniques, Raman and infrared absorption (IR) spectroscopy, and a theoretical model. The Raman spectra were measured in different scattering configurations in order to obtain experimental data for detailed investigation of the phonon symmetries. The gross features of the spectra obtained in different geometries can be explained using general group-theoretical arguments. Using a lattice-dynamics model, we have also calculated the angular dependence of the phonon energies near the centre of the Brillouin zone, as well as the phonon displacements in some high-symmetry directions. The theoretical results are used to interpret the Raman lines in different configurations, and it was possible to estimate that if ionicity of the bonding of 12% is taken in the theoretical model for 4H-SiC, the splitting of the polar TO mode and the shift of the polar LO mode observed in our spectra are well reproduced theoretically. It was also observed that these polar modes have to be classified as longitudinal and transversal with respect to the direction of phonon wave vector, while the rest of the modes remain longitudinal or transversal with respect to the c-axis of the crystal. The Raman lines in the case of 4H SiC have been tentatively labelled with the irreducible representations of the point group of the crystal (C6v).

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No description available.

Les changements climatiques amènent des transformations profondes de l’environnement arctique. La diminution de l’étendue de la couverture de glace permet un accès facilité aux ressources naturelles et aux communautés nordiques. Au Canada, la région arctique est caractérisée par une géographie archipélagique et un réseau de transport rudimentaire. Le transport maritime est le mode privilégié pour l’acheminement du fret aux communautés et aux sites industriels de l’Arctique. La littérature scientifique présente des lacunes importantes au sujet de la navigation commerciale dans l’Arctique canadien. Peu d’études portent sur le trafic de ravitaillement en raison de son volume peu élevé et de la faible diversité des types de produits transportés, bien qu’il s’agisse d’une activité grandement significative pour les populations et l’économie du Nord. Cette recherche vise à combler cette lacune en dressant un portrait du transport maritime et de la performance des opérations portuaires dans l’Arctique canadien. L’étude est structurée en quatre parties. Une analyse du trafic et des échanges maritimes est d’abord réalisée sous trois échelles : internationale, nationale et intra-arctique. Ensuite, l’étude de la flotte et des routes fait ressortir la distribution géographique des transporteurs. Puis, la performance des ports est mesurée grâce à des indicateurs et un système de cotation. Finalement, une évaluation des opérations maritimes arctiques est menée par l’entremise d’informations récoltées lors d’entrevues avec les membres de l’industrie maritime, de conférences et de travail de terrain. Les sujets abordés concernent l’évolution de la desserte, les défis posés par la navigation en milieu arctique et le développement des ports du Nord canadien. Les résultats de l’étude mènent à la conclusion que le transport maritime dans l’Arctique est caractérisé par une croissance positive du volume acheminé et une implication profonde des transporteurs dédiés à la desserte nordique, mais des infrastructures portuaires et maritimes sous-développées. / Climate change brings deep transformations in the Arctic environment. The reduction of the ice cover allows better access to northern communities and natural resources. In Canada, the Arctic region is characterized by an archipelagic geography and undeveloped transportation network. Marine transport is the favoured mode for supplying freight to local communities and industrial sites. The scientific literature shows important gaps on commercial navigation in the Canadian Arctic. Few studies have been conducted on marine traffic in the Arctic due to small tonnage and low product diversity, even though it is a significant activity for the northern people and the regional economy. This research aims to fill this gap by assessing maritime transportation and port operation efficiency in the Canadian Arctic. The structure of this study is four fold. First, a traffic and trade analysis is conducted under three scales: international, national and intra-arctic. Second, a fleet and routing assessment is done by means of carriers’ geographic distribution. Third, port performance is measured through specific indicators. Fourth, an evaluation is held on arctic marine operations through information collected during interviews with members of the maritime industry, workshops and field work. Problems addressed regard evolution of the sealift, challenges brought by Arctic navigation and development of northern Canadian ports. Results of this research lead to the conclusion that Arctic marine transportation displays positive traffic growth and serious involvement by carriers dedicated to Arctic sealift, but under-developed port and maritime infrastructures.

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<p>Accurate quantification of anatomical and pathological structures in the eye is crucial for the study and diagnosis of potentially blinding diseases. Earlier and faster detection of ophthalmic imaging biomarkers also leads to optimal treatment and improved vision recovery. While modern optical imaging technologies such as optical coherence tomography (OCT) and adaptive optics (AO) have facilitated in vivo visualization of the eye at the cellular scale, the massive influx of data generated by these systems is often too large to be fully analyzed by ophthalmic experts without extensive time or resources. Furthermore, manual evaluation of images is inherently subjective and prone to human error.</p><p>This dissertation describes the development and validation of a framework called graph theory and dynamic programming (GTDP) to automatically detect and quantify ophthalmic imaging biomarkers. The GTDP framework was validated as an accurate technique for segmenting retinal layers on OCT images. The framework was then extended through the development of the quasi-polar transform to segment closed-contour structures including photoreceptors on AO scanning laser ophthalmoscopy images and retinal pigment epithelial cells on confocal microscopy images. </p><p>The GTDP framework was next applied in a clinical setting with pathologic images that are often lower in quality. Algorithms were developed to delineate morphological structures on OCT indicative of diseases such as age-related macular degeneration (AMD) and diabetic macular edema (DME). The AMD algorithm was shown to be robust to poor image quality and was capable of segmenting both drusen and geographic atrophy. To account for the complex manifestations of DME, a novel kernel regression-based classification framework was developed to identify retinal layers and fluid-filled regions as a guide for GTDP segmentation.</p><p>The development of fast and accurate segmentation algorithms based on the GTDP framework has significantly reduced the time and resources necessary to conduct large-scale, multi-center clinical trials. This is one step closer towards the long-term goal of improving vision outcomes for ocular disease patients through personalized therapy.</p> / Dissertation