Elevated serum levels of trimethylamine N-oxide (TMAO) were first associated with increased risk of cardiovascular disease (CVD) 10 years ago. Research has since defined that serum TMAO accumulation is controlled by the diet-microbiome-liver-kidney axis. Choline related nutrients are consumed in excess during over-nutrition from a Western diet. The resultant elevated serum TMAO is investigated across various chronic metabolic diseases and many tissue types. While TMAO is most clearly linked to CVD mechanisms in vascular tissue, its molecular effects on metabolic tissues are unclear. Here we report the current standing of TMAO research in metabolic disease context across relevant metabolic tissues including liver, kidney, brain, adipose, and muscle tissues. This review explores the variable TMAO effects in healthy and diseased conditions. Since impaired pancreatic β-cell function is a hallmark of metabolic disease pathogenesis which are largely unexplored in TMAO research, the following primary research results investigate TMAO effects on in vitro functional β-cell mass in relation to healthy and type 2 diabetes (T2D) conditions. Although we hypothesized that TMAO would aggravate functional β-cell mass, the data demonstrate that TMAO improves the T2D phenotype by increasing insulin secretion and production and reducing oxidative stress. Therefore, this work provides crucial support for the emerging context dependent molecular effects of TMAO during metabolic disease progression.

Au Québec, la pandémie de la COVID-19 a entrainé de nombreux questionnements face au système alimentaire, sa durabilité et sa résilience. Cette crise sanitaire a révélé les multiples dépendances de la province, notamment aux importations et à une main- d’œuvre étrangère bon marché, tout en exacerbant les problématiques liées à la distance entre le champ et notre assiette. D’autre part, celle-ci a souligné la fragilité socio- écologique du modèle agricole en place. L’agriculture industrielle met de l’avant plusieurs pratiques aux conséquences destructrices si néfastes pour l’environnement et l’Homme. Devant de tels enjeux, des pratiques alternatives en agriculture ont émergé au Québec dans les dernières décennies, telles que des coopératives agricoles, micro-fermes, l’agriculture urbaine, etc., ainsi que le souhait d’une plus grande autonomie alimentaire pour la province. Seulement, en dépit d’une volonté de limiter l’impact environnemental de l’agriculture sur le territoire québécois, la présence de verrouillages juridico-politiques et socio-économiques limitent le développement de ces alternatives. La présente recherche a déterminé, documenté et analysé la nature de ces verrouillages freinant ou empêchant une transition agroécologique du système alimentaire du Québec. En ayant recours à une revue de la littérature, dix entretiens semi-dirigés avec des acteurs clés du secteur agricole et de l’observation sur le terrain, nous avons documenté et analysé les changements, les réalités et les besoins en agriculture en 2022-2023. Cette étude a contribué à l’évaluation des besoins en agriculture et à l’établissement de stratégies de transformation du système alimentaire du Québec, afin qu’il fasse preuve de durabilité, d’autonomie et de résilience. / In Quebec, the COVID-19 pandemic raised awareness about the food system, its sustainability, and resilience. This health crisis revealed the province's multiple dependencies, notably on imports and cheap foreign labor, while exacerbating issues linked to the distance between the field and our plates. It also highlighted the socioecological fragility of the current agricultural model. Industrial agriculture puts forward several practices with destructive consequences that are harmful to the environment and mankind. Faced with such challenges, alternative agricultural practices have emerged in Quebec in recent decades, such as agricultural cooperatives, micro-farms, urban agriculture, etc., as well as the desire for greater food autonomy for the province. However, despite the desire to limit the environmental impact of agriculture in Quebec, the development of these alternatives is hampered by legal, political, and socio-economic lock-ins. This research has determined, documented, and analyzed the nature of these locks hindering or preventing the agroecological transition of Quebec's food system. Using a literature review, ten semi-structured interviews with key actors in the agricultural sector, and field observation, we documented and analyzed the changes, realities, and needs in agriculture in 2022-2023. This study contributed to the assessment of agricultural needs and the establishment of strategies for transforming Quebec's food system so that it demonstrates sustainability, autonomy, and resilience.

No description available.

Most micro air vehicles rely heavily on reliable GPS measurements for proper estimation and control, and therefore struggle in GPS-degraded environments. When GPS is not available, the global position and heading of the vehicle is unobservable. This dissertation establishes the theoretical and practical advantages of a relative navigation framework for MAV navigation in GPS-degraded environments. This dissertation explores how the consistency, accuracy, and stability of current navigation approaches degrade during prolonged GPS dropout and in the presence of heading uncertainty. Relative navigation (RN) is presented as an alternative approach that maintains observability by working with respect to a local coordinate frame. RN is compared with several current estimation approaches in a simulation environment and in hardware experiments. While still subject to global drift, RN is shown to produce consistent state estimates and stable control. Estimating relative states requires unique modifications to current estimation approaches. This dissertation further provides a tutorial exposition of the relative multiplicative extended Kalman filter, presenting how to properly ensure observable state estimation while maintaining consistency. The filter is derived using both inertial and body-fixed state definitions and dynamics. Finally, this dissertation presents a series of prolonged flight tests, demonstrating the effectiveness of the relative navigation approach for autonomous GPS-degraded MAV navigation in varied, unknown environments. The system is shown to utilize a variety of vision sensors, work indoors and outdoors, run in real-time with onboard processing, and not require special tuning for particular sensors or environments. Despite leveraging off-the-shelf sensors and algorithms, the flight tests demonstrate stable front-end performance with low drift. The flight tests also demonstrate the onboard generation of a globally consistent, metric, and localized map by identifying and incorporating loop-closure constraints and intermittent GPS measurements. With this map, mission objectives are shown to be autonomously completed.

Traditionally, the task of determining aircraft position and attitude for automatic control has been handled by the combination of an inertial measurement unit (IMU) with a Global Positioning System (GPS) receiver. In this configuration, accelerations and angular rates from the IMU can be integrated forward in time, and position updates from the GPS can be used to bound the errors that result from this integration. However, reliance on the reception of GPS signals places artificial constraints on aircraft such as small unmanned aerial vehicles (UAVs) that are otherwise physically capable of operation in indoor, cluttered, or adversarial environments. Therefore, this work investigates methods for incorporating a monocular vision sensor into a standard avionics suite. Vision sensors possess the potential to extract information about the surrounding environment and determine the locations of features or points of interest. Having mapped out landmarks in an unknown environment, subsequent observations by the vision sensor can in turn be used to resolve aircraft position and orientation while continuing to map out new features. An extended Kalman filter framework for performing the tasks of vision-based mapping and navigation is presented. Feature points are detected in each image using a Harris corner detector, and these feature measurements are corresponded from frame to frame using a statistical Z-test. When GPS is available, sequential observations of a single landmark point allow the point's location in inertial space to be estimated. When GPS is not available, landmarks that have been sufficiently triangulated can be used for estimating vehicle position and attitude. Simulation and real-time flight test results for vision-based mapping and navigation are presented to demonstrate feasibility in real-time applications. These methods are then integrated into a practical framework for flight in GPS-denied environments and verified through the autonomous flight of a UAV during a loss-of-GPS scenario. The methodology is also extended to the application of vehicles equipped with stereo vision systems. This framework enables aircraft capable of hovering in place to maintain a bounded pose estimate indefinitely without drift during a GPS outage.

The thesis consists of the novel, Stargate Atlantis: Exogenesis (Whitelaw and Christensen, 2006a) and an accompanying exegesis. The novel is a stand-alone tie-in novel based on the television series Stargate Atlantis (Wright and Glassner), a spin-off series of Stargate SG-1 (Wright and Cooper) derived from the movie Stargate (Devlin and Emmerich, 1994). Set towards the end of the second season, Stargate Atlantis: Exogenesis begins with the discovery of life pods containing the original builders of Atlantis, the Ancients. The mind of one of these Ancients, Ea, escapes the pod and possesses Dr. Carson Beckett. After learning what has transpired in the 10,000 years since her confinement, the traumatised Ea releases an exogenesis machine to destroy Atlantis. Ea dies, leaving Beckett with sufficient of her memories to reveal that a second machine, on the planet Polrusso, could counter the effects of the first device. When the Atlantis team travel to Polrusso, what they discover has staggering implications not only for the future of Atlantis but for all life in the Pegasus Galaxy. The exegesis argues that both science and science fiction narrate the dissolution of ontological structures, resulting in cognitive estrangement. Fallacy writers engage in the same process and use the same themes and tools as science fiction writers to resolve cognitive estrangement: they technologise mythology. Consequently, the distinction between fact and fiction, history and myth, is blurred. The exegesis discusses cognitive estrangement, mythology, the process of technologising mythology and its function as a novum that facilitates the resolution of cognitive estrangement in both fallacy and science fiction narratives. These concepts are then considered in three Stargate tie-in novels, with particular reference to the creative work, Stargate Atlantis: Exogenesis.

Micro air vehicles have recently gained popularity due to their potential as autonomous systems. Their future impact, however, will depend in part on how well they can navigate in GPS-denied and GPS-degraded environments. In response to this need, this dissertation investigates a potential solution for GPS-denied operations called relative navigation. The method utilizes keyframe-to-keyframe odometry estimates and their covariances in a global back end that represents the global state as a pose graph. The back end is able to effectively represent nonlinear uncertainties and incorporate opportunistic global constraints. The GPS-denied research community has, for the most part, neglected to consider fixed-wing aircraft. This dissertation enables fixed-wing aircraft to utilize relative navigation by accounting for their sensing requirements. The development of an odometry-like, front-end, EKF-based estimator that utilizes only a monocular camera and an inertial measurement unit is presented. The filter uses the measurement model of the multi-state-constraint Kalman filter and regularly performs relative resets in coordination with keyframe declarations. In addition to the front-end development, a method is provided to account for front-end velocity bias in the back-end optimization. Finally a method is presented for enabling multiple vehicles to improve navigational accuracy by cooperatively sharing information. Modifications to the relative navigation architecture are presented that enable decentralized, cooperative operations amidst temporary communication dropouts. The proposed framework also includes the ability to incorporate inter-vehicle measurements and utilizes a new concept called the coordinated reset, which is necessary for optimizing the cooperative odometry and improving localization. Each contribution is demonstrated through simulation and/or hardware flight testing. Simulation and Monte-Carlo testing is used to show the expected quality of the results. Hardware flight-test results show the front-end estimator performance, several back-end optimization examples, and cooperative GPS-denied operations.

Micro aerial vehicles and other autonomous systems have the potential to truly transform life as we know it, however much of the potential of autonomous systems remains unrealized because reliable navigation is still an unsolved problem with significant challenges. This dissertation presents solutions to many aspects of autonomous navigation. First, it presents ROSflight, a software and hardware architure that allows for rapid prototyping and experimentation of autonomy algorithms on MAVs with lightweight, efficient flight control. Next, this dissertation presents improvments to the state-of-the-art in optimal control of quadrotors by utilizing the error-state formulation frequently utilized in state estimation. It is shown that performing optimal control directly over the error-state results in a vastly more computationally efficient system than competing methods while also dealing with the non-vector rotation components of the state in a principled way. In addition, real-time robust flight planning is considered with a method to navigate cluttered, potentially unknown scenarios with real-time obstacle avoidance. Robust state estimation is a critical component to reliable operation, and this dissertation focuses on improving the robustness of visual-inertial state estimation in a filtering framework by extending the state-of-the-art to include better modeling and sensor fusion. Further, this dissertation takes concepts from the visual-inertial estimation community and applies it to tightly-coupled GNSS, visual-inertial state estimation. This method is shown to demonstrate significantly more reliable state estimation than visual-inertial or GNSS-inertial state estimation alone in a hardware experiment through a GNSS-GNSS denied transition flying under a building and back out into open sky. Finally, this dissertation explores a novel method to combine measurements from multiple agents into a coherent map. Traditional approaches to this problem attempt to solve for the position of multiple agents at specific times in their trajectories. This dissertation instead attempts to solve this problem in a relative context, resulting in a much more robust approach that is able to handle much greater intial error than traditional approaches.

Kroppsuppfattning påverkar vår livskvalitet. Utöver att prestera på tävling behöver tyngdlyftare och styrkelyftare delta på en invägning, där deras kroppsvikt avgör vilken viktklass de tävlar i. Syftet med studien var att undersöka om det fanns ett samband mellan lyftares kroppsuppfattning och upplevelse av att vara aktiv och tävlande inom tyngdlyftning och/eller styrkelyft. Metod: 210 svenska tyngdlyftare och styrkelyftare med tävlingserfarenhet i åldrarna 15–70 år deltog i studien. Deltagarna svarade på en digital enkät som inkluderade ett av författaren nyskapat instrument om förekomst av beteenden och upplevelser av att tävla i en viktklassidrott, samt Body Esteem Scale for Adolescents and Adults om kroppsuppfattning. Resultat: Signifikant positiva korrelationer av måttlig styrka påvisades mellan kroppsuppfattning och tävlingsupplevelse, samt mellan kroppsuppfattning och viktupplevelse. Svag positiv korrelation påvisades mellan kroppsuppfattning och invägningsupplevelse. 60 % av studiedeltagarna rapporterade positiv kroppsuppfattning och 40 % rapporterade blandad/splittrad eller negativ kroppsuppfattning. Slutsats: Studiens resultat indikerar att kroppsuppfattning och upplevelse av att tävla, upplevelse av sin kroppsvikt och att tävla i viktklass(er), samt upplevelse av invägning har ett samband. Då 40 % av populationen rapporterade blandad/splittrad eller negativ kroppsuppfattning tyder resultaten på praktiska förbättringsmöjligheter där idrottares kroppsuppfattning kan förbättras. / Body image affects our quality of life. In addition to performing in competition, weightlifters and powerlifters need to participate in a weigh-in, where their body weight determines which weight class they compete in. The purpose of the study was to investigate whether there was a relationship between lifters’ body image and experience of being active and competing in weightlifting and/or powerlifting. Method: 210 Swedish weightlifters and powerlifters with competition experience aged 15–70 years participated in the study. The participants responded to a digital questionnaire that included an instrument newly created by the author on the prevalence of behaviours and experiences of competing in a weight class sport, as well as the Body Esteem Scale for Adolescents and Adults. Results: Positive correlations of statistical significance and of moderate strength were found between body image and competition experience, as well as between body image and weight experience. Weak positive correlation was demonstrated between body image and weigh-in experience. 60 % of the participants reported positive body image and 40 % reported mixed/split or negative body image. Conclusion: The results of the study indicate a relationship between body image and experience of competing, experience of one's body weight and competing in weight class(es), as well as experience of weigh-ins. As 40 % of the population reported mixed/split or negative body image, the results indicate practical opportunities where athletes’ body image can be improved.

Uppsatsens problemställning rör frågan om det är möjligt att utröna hur tystnaden framställs i Nelly Sachs sena lyrik och vad den säger, och huruvida det är möjligt att relatera denna tystnad till en medveten kontra omedveten uttrycksform. Min avsikt är alltså att undersöka de strukturer eller mönster – medvetna som omedvetna – som står att finna i Sachs lyrik som kan kopplas samman med denna tystnad, inte för att fastställa en dikts betydelse utan för att undersöka hur tystnadens närvaro tar sig uttryck och låter sig urskiljas i hennes dikter. Jag gör detta dels genom att i uppsatsens del ett redogöra för hur tystnaden som tema och problem uppfattas i den tidigare forskningen. I del två försöker jag fördjupa dessa rön genom en vidare koppling till Sachs modernistiska formspråk, och med hjälp av bland annat psykoanalytisk teori görs ett antal närläsningar av hennes senare dikter. Den teoretiska ramen för diskussionen hämtar jag alltså främst från psykoanalysen som på olika vis uppmärksammar lakuner, trauman och omedvetna dimensioner i språket, vilket jag menar kan öka förståelsen för tystnadens problematik hos Sachs. Undersökningen genomförs närmare bestämt i linje med Julia Kristevas teoribildning. Kristeva är psykoanalytiker och även professor i lingvistik och har formulerat teorier om det poetiska språket som visat sig fruktbara i min läsning av det ”ordlösa språket” hos Sachs. Kathrin M. Bower refererar träffande till Kristevas arbete som ”Kristeva’s distinctive brand of psychoanalytic semiotics”.