In this thesis I assessed the causes of long-term changes in two large, commercially important decapod crustacean populations, American lobster (Homarus americanus) and snow crab (Chionoecetes opilio), in the northwest (NW) Atlantic Ocean. By combining available time-series data, including commercial landings, research surveys, and local ecological knowledge (LEK), I explored the causes of an observed ecosystem shift in the NW Atlantic (~1950–2009) which entailed a region-wide decline of groundfish and an increase in benthic invertebrates, including these decapods. Three hypotheses were examined to explain the increase in decapod abundance: (1) the predation hypothesis, whereby a decrease in predatory groundfish led to an increase in their decapod prey (top-down effects); (2) the climate hypothesis, whereby changes in temperature or other climatic variables helped to increase decapod numbers (bottom-up effects); and (3) the anthropogenic hypothesis, whereby changes in fishing pressure drove decapod population dynamics. I explored these hypotheses separately for lobster and snow crab, which may experience different ecological and commercial pressures. First, I investigated the interactions between predatory groundfish and lobster in the inshore region of southwest Nova Scotia. Long-term fisheries-independent abundance indices for lobsters and their predators are available for Gulf of Maine (GOM) waters in the USA, but not in Canada. To address research gaps I designed and executed a survey to collect the LEK of lobster fishermen fishing in the Canadian GOM. Forty-two fishermen were interviewed. Corresponding survey results from the USA were compared to the LEK results. Both sources provided evidence for a top-down effect (predation release), contributing to observed increases in GOM lobster abundance and landings. Second, I explored relationships between lobster abundance and landings in the NW Atlantic as they may relate to temporal changes in predators, temperature, climate (North Atlantic Oscillation Index, NAOI), and fishing. Available landings data and fisheries-independent abundance estimates were collated to investigate trends in lobster abundance and catch. Links between lobster, groundfish, temperature and climate indices were explored using mixed effects models. Results offered partial support for the predation hypothesis, namely in the waters off Newfoundland, Nova Scotia, and southern New England as well as broad support for a climate effect on early life stages. This effect appeared related to a region-wide climate signal, the NAOI, but was independent of changes in water temperature. Fishing effort appeared to be following lobster abundance, rather than regulating abundance in a consistent way. Third, variation in snow crab abundance was examined through meta-analysis of time-series data of cod and crab abundance and temperature. Temperature had opposing effects on the two species: snow crab abundance was negatively correlated with temperature whereas cod and temperature were positively related. Controlling for the effect of temperature, the analysis revealed significant negative interactions between snow crab and cod abundance, with cod leading snow crab up to a five-year lag. Results indicate that snow crab is largely influenced by temperature during early post-settlement years and becomes increasingly regulated by top-down mechanisms as they approach fishery recruitment. Overall, I conclude that both climate and predation can act as population controls on large decapod populations, but these variables affect decapods at different life stages.

Forested watersheds in western North America are subject to significant change from natural and anthropogenic disturbance, including wildfire. Forest canopy changes have subsequent impacts on sub-canopy snow processes. A simple, process-based point energy balance model was developed to quantify differences in energy balance characteristics between a burned and a healthy forest stand. Potential model uncertainties were identified using sensitivity analyses. Simulated snowmelt accurately recreated measured snowmelt, providing confidence in the model’s ability to simulate energy balance processes in subcanopy environments where wind redistribution and sublimation are not major drivers of the local snowmelt energy balance. In the burned stand, sub-canopy snow accumulation was greater but melted more rapidly than in the healthy stand. The removal of forest canopy resulted in more energy available for snowmelt, including higher short-wave and lower long-wave radiation, and increased turbulent fluxes. Burned stands should be considered a separate land cover type in larger scale watershed models. / xii, 129 leaves : ill,, map ; 29 cm

Le présent mémoire de recherche-création a pour objet les réécritures théâtrales des contes. Si le conte merveilleux et le théâtre sont a priori deux genres littéraires distincts de par leur origine, leur nature et leur mode d’expression, ils présentent néanmoins des points communs qui facilitent la transgression des frontières génériques. Aussi les dramaturges se sont-ils parfois risqués à proposer des adaptations de contes merveilleux pour le théâtre. C’est par exemple le cas de Joël Pommerat, qui a récemment proposé des transpositions scéniques de trois contes traditionnels, revisitant et actualisant thèmes et personnages. Dans cet essai, je m’intéresse tout d’abord aux éléments qui favorisent la réécriture théâtrale des contes. Je m’interroge ensuite sur la manière dont Pommerat, qui fonde sa réflexion sur les apports de la philosophie, de la sociologie et de la psychanalyse, prépare ses spectacles ; ce que j’illustre en mettant en lumière la méditation menée par l’auteur sur le travail du deuil dans son spectacle Cendrillon. À l’instar de Pommerat, je présente enfin une étude psychanalytique des personnages du conte Blanche-Neige des frères Grimm. La création que je propose consiste en une transposition théâtrale du conte Blanche-Neige des frères Grimm, qui déplace situations et personnages dans le monde contemporain de l’entreprise. / The purpose of this research-creation master thesis is to rewrite the theatrical aspects of the fairy tales. While storytelling and theatre are a priori two literary genres distinct in origin, nature and mode of expression, they nevertheless share common qualities that facilitate the transgression of generic boundaries. So playwrights have sometimes ventured to offer adaptations of fairy tales for the theatre. This is the case, for example, of Joël Pommerat, who recently proposed scenic transpositions of three traditional fairy tales, revisiting and updating themes and characters. In this essay, I am first interested in the elements that promote the theatrical rewriting of fairy tales. I then ask myself how Pommerat, who bases his reflection on the contributions of philosophy, sociology and psychoanalysis, prepares his shows ; what I illustrate by highlighting the author's reflections on the work of mourning in his play Cinderella. Like Pommerat, I finally present a psychoanalytical study of the characters in the Grimm brothers' Snow White tale. The creation I propose consists of a theatrical transposition of the Grimm brothers' Snow White tale, which moves situations and characters into the contemporary world of business.

Le biome boréal, emmagasinant d’importantes quantités de carbone en son sol et recouvrant une majorité du territoire alaskien, fennoscandien et russe, contribue grandement au système climatique. Toutefois, les variabilités climatiques et les propriétés de l’écosystème, notamment en ce qui a trait à la présence ou l’absence de pergélisol, complexifient la quantification de la variabilité des bilans de carbone du biome boréal, au sein duquel se retrouvent des écosystèmes forestiers, lentiques et de zones humides. Ces bilans de carbone sont grandement influencés par le début et la fin de la saison de croissance photosynthétique, étant à leur tour dépendants de plusieurs variables environnementales telles que la température de l’air et du sol, le contenu du sol en eau, les stades de développement de la végétation, etc. Cette recherche vise à quantifier l’impact de ces variabilités environnementales sur la variabilité des moments où se produisent le début et la fin de la saison de croissance photosynthétique, en distinguant les forêts boréales avec et sans pergélisol. La saison de croissance photosynthétique est caractérisée à partir de la productivité primaire brute dérivée de mesures covariance des turbulences provenant de 40 sites-années d’observation à travers la forêt boréale nord-américaine où l’épinette noire est l’espèce d’arbre dominante. Les variables environnementales considérées étaient les températures de l’air et du sol, les stades de développement de la végétation, le couvert nival, le rayonnement photosynthétiquement actif et le contenu du sol en eau. Le cadre statistique choisi incluait le calcul des coefficients de corrélations de Pearson, l’analyse des points communs et la modélisation par équations structurelles. Les résultats de cette étude montrent que la variabilité du début de la saison de croissance dans les sites sans pergélisol est contrôlée directement par la variabilité annuelle des stades de développement de la végétation ainsi que par le moment où survient le dégel du sol. Ce résultat souligne ainsi l’importance de l’accès à l’eau liquide du sol afin que la végétation initie la photosynthèse. Aucune variable environnementale ne pouvait significativement expliquer le contrôle du début de la photosynthèse au sein des sites avec pergélisol. À l’automne, le contenu du sol en eau ainsi que le début du couvert nival influencent directement la variabilité de la fin de la saison de croissance photosynthétique. Il est alors montré que la disponibilité de l’eau peut mener à une cessation plus hâtive de la photosynthèse à l’automne. L’effet de l’apparition du couvert nival est quant à lui opposé dans les sites avec et sans pergélisol. Son retard dans les sites sans pergélisol témoigne d’une température de l’air suffisamment élevée pour que les précipitations tombent sous forme liquide, prolongeant ainsi les activités photosynthétiques. Son retard dans les sites avec pergélisol signifie plutôt des précipitations neigeuses moindres, retardant ainsi l’apparition d’une couche isolante pour le sol, qui aurait pu allonger la saison de croissance photosynthétique. Cette étude contribue à clarifier les processus contrôlant le début et la fin de la saison de croissance photosynthétique et aidera à améliorer la compréhension des effets des changements climatiques sur la force du puits de carbone de la forêt boréale nord-américaine. / The boreal forest, storing large amounts of carbon in its soil and covering a majority of the Alaskan, Canadian, Fennoscandian and Russian territory, is an integral part of the climate system. However, climatic variability and ecosystem properties, particularly with regards to the presence or absence of permafrost, limits our understanding of the carbon balance variability in the boreal biome, which comprises forest, lake and wetland ecosystems. The boreal carbon sink-source strength is greatly influenced by phenological events, including the start and end of the photosynthetic growing season, which are themselves dependent on several environmental variables such as air and soil temperature, soil water content, vegetation development stages, etc. This research aims to provide new insights on the influence of environmental variability on the variability in the timing of the photosynthetic growing season, by broadly distinguishing between boreal forests with and without permafrost. The photosynthetic growing season is characterized using gross primary productivity derived from eddy covariance measurements of net ecosystem carbon dioxide exchange. Data from 40 black spruce- dominated site-years of observation across the North American boreal forest are used. The considered environmental predictors were air and soil temperatures, vegetation development stages, snow cover, photosynthetically active radiation and soil water content. The statistical framework included the calculation of Pearson correlation coefficients, commonality analyses and structural equation modeling. This study shows that the variability in the start of the growing season in permafrost-free sites is directly controlled by the variability in vegetation development stage as well as by the thawing of seasonally frozen ground. This result thus emphasizes the importance of access to liquid soil water for the vegetation to initiate photosynthesis. No environmental variable could significantly explain photosynthesis recovery in sites with permafrost. In fall, the soil water content as well as the start of snow cover directly influence the variability in the end of the photosynthetic growing season. These results suggest that the availability of water can limit photosynthesis in the fall. The effect of snow cover is opposite in sites with and without permafrost. A delay in the appearance of continuous snow cover in sites without permafrost indicates that the air temperature is high enough for precipitation to fall in liquid form and for photosynthesis to continue. In contrast, its delay in sites with permafrost indicates less snowfall, thus delaying the appearance of an insulating layer for the soil, which could have lengthened the photosynthetic growing season. This study sheds light on the controls of the annual variation of the timing of the photosynthetic growing season and will help understanding of the effects of climate change on the strength of the North American boreal forest carbon sink.

No description available.

<p dir="ltr">Seafood plays a pivotal role in global economies, livelihoods, and nutritional security. However, climate change and global pandemics pose significant threats to seafood harvests, production, supply chains, and marketing channels. The focus of my thesis is to understand the impact of external factors on our seafood resources and explore adaptive strategies in the face of uncertainties. We utilize economics techniques to study human-nature systems by zooming into social elements (government agencies, industry stakeholders, and fish farmers/fishermen) and aquatic resources. The three essays of my thesis delve into this inquiry from the perspectives of government, industry, and market, accordingly.</p><p dir="ltr">The first chapter in my thesis, <i>Climate Change and Snow Crab Harvest - Applying Random Effect Estimators with Instrumental Variable</i>, estimates the snow crab harvest function with unbalanced panel data of eastern Bering Sea snow crab, Canadian snow crab, Japanese snow crab, and Barents Sea snow crab. Specifically, we analyze the relationship between snow crab biomass, stock, and catch. To address the endogeneity of stock in the harvest function, climate change indicators are selected as instrumental variables. We identify that the Arctic Sea ice extent is effective in addressing the endogeneity and the random effects instrumental variable model with error components two stage least squares estimator performs the best to control heterogeneity. We find that a 1% increase in snow crab fishing effort is associated with a 0.42% increase in snow crab harvest, and a 1% increase in snow crab stock causes a 0.98% increase in snow crab harvest. The reported estimates indicate a large stock-harvest elasticity and provide supporting evidence for government fishery agencies to prioritize stock enhancement in policy designs.</p><p dir="ltr">The second chapter, <i>Online Media Sentiment Analysis of Shrimp and Salmon in the United States</i>, employs online media analytics on shrimp and salmon in the US to provide insights into consumer perceptions and potential demand signals for seafood. Search hits and mentions are quantified for top sources, domains, and prevalent terms. In addition, sentiment drivers and sentiment values are identified and calculated using natural language processing tools. The results reveal that the occurrence of peak mentions does not necessarily coincide with the peak of net sentiment, and farmed seafood consistently exhibits lower net sentiments compared to their wild counterparts. Autoregressive modeling is conducted to predict the dynamics of seafood’s net sentiments. The regional analysis demonstrates that public attitudes toward both farmed shrimp and salmon in the East North Central region exhibit a more positive net sentiment, while the New England and Middle Atlantic regions tend to have a lower net sentiment for farmed shrimp and salmon, respectively. The fitted forecast model serves as a supplementary tool for industry stakeholders to quickly respond to future public perceptions. Regional statistics also help the seafood industry tailor business strategies to different regions.</p><p dir="ltr">In the third chapter, <i>Comparative Case Study of Small-Scale Fish Processing for Local Seafood Supply</i><i>,</i> we examine the feasibility of utilizing a shared-use commercial kitchen and on-farm kitchen to support small-scale local fish processing, which helps diversify marketing channels in the US Midwest and supply seafood to local food systems. A case study of each facility type is assessed for economic viability for fish farmers. The financial analysis suggests farmers interested in processing tilapia or rainbow trout from 2,500 lbs to 5,000 lbs per year utilize rental commercial kitchens. A minimum of 15% markup and processing of 10,000 lbs/year tilapia is required to make the on-farm kitchen option more viable. For farmers who process rainbow trout, 10,000 lbs/year with a 10% markup using an on-farm kitchen is a better choice. Factoring in the stochastic variability of raw product prices, rental rates, and set-up costs, we provide simulated ranges for economic metrics including profitability index, payback period, and net present values. The reports of estimated costs, revenues, and breakeven prices, provide fish farmers with suggested selling prices, kitchen choices, and production levels to achieve optimum profits under risks.</p>

No description available.

Light Detection and Ranging (Lidar) is a kind of active sensor that emits a laser pulse and primarily measures the time of flight of the returning pulse and uses it to construct a 3D point cloud of the scene around the lidar sensor. The constructed point cloud is an essential asset for the control of autonomous vehicles, and especially today, an essential basis for the training of autonomous vehicle control models. However, it remains time-consuming, high-risk and expensive to acquire the amounts of data necessary to train the rather complex modern control models. As such, generating the point cloud through simulations becomes a natural solution. Yet, many lidar simulations today produce ideal point clouds, corrected only by random noise, without considering the physical reasons behind the imperfections visible in real lidar point clouds. The aim of this study was to investigate real-time simulation models for disturbances that may cause imperfections in lidar data. From a base investigation of lidar, disturbances were found, models were investigated and finally a real-time implementation of Atmospheric Effects and attenuation from Beam Divergence was evaluated. It was found that the implemented models could produce physically accurate lidar point placement while keeping the computational time low enough for real-time evaluation. However, to achieve correct separation of target hit rates under Atmospheric Effects, as high as 34% of the points had to be dropped. Additionally, the intensity of the return points could not be properly verified. From these results it can be concluded that, with additional verification and adjustment, the presented models can achieve good results for evaluation in real-time. The results of this study thus serve as a support for future developments of realistic real-time lidar simulations, for use in development of autonomous vehicle control models and implementation of digital twins.

The following is a collection of original poetry. The manuscript consists of an introduction explaining influences and style, and four chapters of poems categorized by subject matter: object/nature, writing/creativity, relationships, and family/figures. INDEX WORDS: Poetry, Poem

xv, 298 p. ; ill. (chiefly col.), maps (chiefly col.) A print copy of this thesis is available through the UO Libraries under the call number: AAA F868.Y6 G47 2004 / This study describes existing conditions, evaluates significance and historic integrity, and recommends treatment strategies to preserve historic elements of the Nevada Fall Corridor cultural landscape in Yosemite National Park. It reports findings from field investigation that examined and inventoried landscape features such as stone retaining walls, treadway material, bridges and causeways, and water features on both current-use and abandoned trail segments. The site was examined numerous times over a three-month period, with a followup visit one year later. Libraries and other archives were consulted for written and photographic historic documentation, which were analyzed against current conditions. The process also involved review of comparison documents as well as national guidelines set forth by the National Park Service. / Adviser: Melnick, Robert Z.