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Syfte: Att ta reda på hur lång livslängd en bildplatta har avseende slitage och bildkvalité.Material och metod: Tre fabriksnya bildplattor användes för att undersöka hur en enskild faktor i arbetsgången för bildgenerering påverkar bildkvalitén. Den första plattan exponerades och skannades 300 gånger. Platta nummer två användes för att undersöka effekten av totalt 300 av- och påtagningar i en frigolithållare, och platta tre användes för motsvarande test av en plasthållare. Exponering skedde utan patient och mot en neutral bakgrund. För samtliga plattor togs i initialskedet en referensbild, och resulterande bilder från testerna granskades i Planmeca Romexis 3.8 och bedömdes enligt en skala 0-3. Plattorna i sig granskades även okulärt, och test av uniformitet gjordes av referensbild och bild 300 i serie 1 med hjälp av ImageJ. Resultat: Samtliga bilder från samtliga plattor bedömdes vara likvärdiga med referensbild. Vid okulär granskning var reporna klart mer uttalade hos den platta som skannats 300 gånger, men reporna återfanns endast på den sida som ej är avsedd att exponeras. Test av uniformitet fann ingen skillnad mellan referensbild och bild nr 300 i serie 1. Slutsats: Studien visar att varken röntgenexponering, skanning eller av- och påtagning i hållare av två olika slag har någon inverkan på bildkvalité efter 300 upprepningar då momenten gjordes var för sig. Vi konkluderar att plattan sannolikt är som mest sårbar då den placeras intraoralt, och föreslår att alla moment gjorda i följd delvis kan svara för den reduktion av bildkvalité som observerats i andra studier. / Aim: To determine the longevity of photostimulable storage phosphor plates (PSPs) with respect to wear and image quality. Method: Three brand new PSPs were used to assess how a solitary factor in the picture generation process affects the picture quality. The first plate was exposed and scanned 300 times. Plate number two was used to assess the effect of mounting and demounting the plate 300 times onto a holder made of styrofoam, and the third plate was used for a corresponding test with a plastic holder. A flat surface was exposed and no patients were involved. A reference picture was taken initially for each plate, and the resulting pictures from the tests were viewed using Planmeca Romexis 3.8 and were evaluated on a scale from 0-3. The individual plates also underwent ocular inspection, and a uniformity test was performed on the first and last picture taken with plate 1, using ImageJ. Results: Each picture from each plate was deemed equivalent to the reference picture. The ocular inspection revealed a more distinct band of scratches on the plate that was scanned the most, although the scratches were only found on the side not meant to receive exposure. No difference in uniformity was found between the first and last picture taken using plate 1. Conclusion: X-ray exposure, scanning and mounting and demounting of PSPs onto holders of two different kinds do not affect the picture quality after 300 repetitions when done separately. We conclude that the plate is likely most susceptible to wear when placed intraorally, and suggest that all the steps made in succession can partly account for the reduction in picture quality observed in other studies.

<p>Aging involves the progressive decline of physical performance and effective metabolic regulation. To date, dietary interventions to slow this deterioration have shown limited success. I tested the effectiveness of a complex dietary supplement (that targets five key mechanisms of aging) for ameliorating age-related declines in physical activity, metabolism and energetic efficiency in mice. Supplemented mice maintained youthful levels of daily physical activity in old age, compared with a progressive decline in untreated controls. The diet also influenced aspects of metabolic rate, as supplemented mice showed age-related increases in fasting oxygen consumption and respiratory quotient compared to declines in these biomarkers in untreated mice. Furthermore, oxygen consumption over 24-h was significantly lower in supplemented mice in spite of being more active than untreated mice. Taken in conjunction with higher resting respiratory exchange ratios across age, this suggests that supplemented mice may utilize more carbohydrate than lipid as an energy substrate and they may express increased metabolic efficiency. These results hold promise for augmenting youthful athleticism and extending geriatric functionality. I also assessed the impact of the supplement on age- related changes in biomarkers of oxidative stress in heart and kidney samples from normal (Nr) and transgenic (Tg) mice that over-express growth hormone. Measures of whole-tissue H2O2 in the heart showed no significant changes in Nr or Tg mice, but catalase activity was ~33% higher in supplemented Nr and Tg compared to untreated controls. Kidney tissue from Nr mice showed significant and opposite age-related trends of H2O2, increasing in supplemented mice and decreasing in untreated controls, however, no changes were observed in Tg mice. Catalase activity in kidney tissue remained unchanged in both genotypes regardless of diet. Furthermore, the ratio of reduced to oxidized glutathione was 43% higher in urine from older (>12 months-old) supplemented mice, indicative of substantially lower whole-body oxidative status. Lastly, older supplemented mice showed improved whole-body glucose tolerance compared with untreated counterparts. These results confirm that the supplement reduces aspects oxidative stress and improves insulin sensitivity, two of the key design criteria for formulating the supplement. This work represents proof of principle that complex dietary supplements can extend functional capacities associated with metabolism and energetic efficiency into older ages.</p> / Master of Science (MSc)

Financial services regulators are tasked with balancing the conflicting roles of empowering and policing their regulated communities. In order to be effective, agencies must be able to accomplish both tasks. This analysis examines several determinants of effectiveness among U.S. bank regulators. Using statistical and narrative analyses, it examines factors that have contributed to the regulatory effectiveness of the National Credit Union Administration, Office of the Comptroller of the Currency, and Office of Thrift Supervision. The study focused on the relationships between regulatory ability to prevent failures and influences including agency longevity, ability to manage complexity, appointee and staff qualities, mission stability, regulatory style, and resources. Agency longevity and resources had the greatest impact on effectiveness among the cases that were examined. Additionally, this study proposes a typology that suggests that more effective regulators are able to balance information from their regulated communities with a public interest orientation. This allows them to have current information regarding emerging regulatory issues but also to avoid becoming too reliant on their supervised institutions for information. / Ph. D.

The effects of temperature on emergence, development, oviposition, longevity and fecundity of <i>Cotesia orobenae</i> Forbes (Hymenoptera: Braconidae) were studied. Development time of parasitoid pupae decreased as temperature increased to 35°C. Temperatures between 20 and 25°C were most suitable for parasitoid development, oviposition and fecundity. Longevity was significantly affected by temperature, and was greatest between I5 and 20°C for both sexes. Sex ratios obtained from virgin females, females mated once and females exposed to multiple mating were compared. Virgin females produced only males, those with single or multiple mating produced more females than males. <i>Cotesia orobenae</i> exposed to five densities of third instar cross-striped cabbageworm, <i>Evergestis rimosaiis</i> (Guenee) (Lepidoptera: Pyralidae), for 24 h showed differences in percent parasitization among the treatments. The highest number of parasitoid cocoon masses was obtained from a density of 10 hosts. / Ph. D.

Nothing is perfect, and this includes the ability to maintain homeostasis within the cell with age. Factors such as aging, chemicals, and gene dysfunction disrupt cellular homeostasis, leading to increased stress and compromising the ability of animals to maintain a healthy lifespan. Dysregulated homeostasis can be detrimental on an organismal level, impacting locomotion, and on a cellular level causing proteins to misfold and become aggregates, which are toxic to cells. Toxic protein aggregation and loss of locomotory function are key hallmarks of several age-related diseases. My Ph.D. work examined the collapse of homeostasis on electrotaxis, the age-associated increase in proteotoxicity, the decline in longevity, and neuronal and muscle health. On a behavioural level I demonstrated that loss of various components of the MT-UPR, ER-UPR, and HSR modulated the speed of animals. Additionally, I found that activation of stress responses due to chemicals and exercise reduced and increased the speed of animals respectively. On a cellular level I elucidated potential mechanisms by which Mesencephalic Astrocyte Derived Neurotrophic Factor (MANF) affects the stress response to maintain homeostasis and prevent protein aggregation. I observed the novel localization and role of MANF in lysosomes to potentially act as a critical regulator of the stress response to maintain proteostasis, neuronal health and longevity, thereby bringing balance to the cell. Furthermore, the broad tissue expression of MANF revealed its localization to muscles. This supports the ability of MANF to act as more than a neurotrophic factor as it was found to be required for muscular health in animals in an age-dependent manner. Overall, my Ph.D. research has provided new insights into the stress response and behaviour and the precise role of MANF in mediating stress response signaling to promote organismal and cellular fitness. / Dissertation / Doctor of Science (PhD) / Cellular perturbations or stress disrupt homeostasis, activating multiple stress responses. Activation of the stress response can determine the fate of an organism and is crucial to its health. Although the stress response pathways are generally understood, little is known about how the stress responses preserve animal behaviour or how they are regulated to promote organismal survival. My work has provided a basis for how stress responses affect behaviour positively and negatively in animals. I found that the stress response required mesencephalic astrocyte derived neurotrophic factor (MANF) to promote organismal survival. My thesis determined that MANF acts as more than a neurotrophic factor. MANF was found to not only be essential in neuronal health but also longevity and muscle health. Overall, this thesis demonstrated the impact of stress response on behaviour and the potential mechanism by which MANF is cytoprotective in whole organisms.

[pt] A longevidade populacional representa uma das maiores conquistas da humanidade. No entanto, observa-se que o envelhecimento é recorrentemente tratado com preocupação, sugerindo mais declínios, perdas e obstáculos. Este trabalho explora visões contemporâneas e mais otimistas sobre o envelhecimento e a longevidade populacionais, assim como meios de contribuir para que a velhice seja reconhecida como uma fase da vida que traz também, soluções, progresso e florescimento à sociedade, mais do que apenas desafios insolúveis. Ele parte da premissa de que – a exemplo das contestações lideradas durante a juventude – a geração nascida entre 1945 e 1964, hoje, está à frente de nova mudança: a de ter mais de 50 anos no século XXI. Nesse sentido, busca-se caminhos para a promoção de projetos de vidas longevas com propósito, produtivas e alinhadas com os tempos atuais e futuros. Incorpora-se as ideias de que o design é uma atividade projetual instrumentada para elaborar cursos de ação destinados a mudar realidades existentes em outras preferíveis e que todos somos designers, consequentemente, capazes de projetar novas longevidades. Seu objetivo é ampliar as oportunidades de projetos que valorizem os benefícios da longevidade e sirvam de modelo para novas formas de viver a velhice. Três perspectivas orientam este trabalho: a psicologia positiva, que enfatiza o bem-estar e a felicidade, a teoria do desenvolvimento psicossocial de Erik Erikson, que destaca a generatividade como possibilidade a partir dos 45 anos e a que apresenta o papel do design como agente de transformação. Explora-se temas como idadismo, economia prateada e educação continuada, entre outros que ganham relevância frente à megatendência nomeada de sociedade prateada. / [en] Population longevity stands as one of humanity s greatest achievements. However, aging is often approached with concern, implying more declines and obstacles than advancements. This work explores contemporary, optimistic views on population aging and longevity, aiming to recognize old age as a phase that brings solutions, progress, and flourishing to society. It starts from the premise that the generation born between 1945 and 1964 leads a new change: being over 50 in the 21st century. It seeks pathways to promote purposeful, productive, and contemporary projects for long-lived lives. It embraces the idea that design is instrumental in shaping preferred realities and that we all have the capacity to design new longevities. Its objective is to expand opportunities for projects valuing the benefits of longevity and serving as models for new ways of aging. Three perspectives guide this work: positive psychology, Erik Erikson s psychosocial development theory highlighting generativity from age 50, and the role of design as a transformative agent. It explores themes like ageism, the silver economy, and lifelong learning, relevant in the era of the so-called silver society megatrend.

L’explosion récente du nombre de centenaires dans les pays à faible mortalité n’est pas étrangère à la multiplication des études portant sur la longévité, et plus spécifiquement sur ses déterminants et ses répercussions. Alors que certains tentent de découvrir les gènes pouvant être responsables de la longévité extrême, d’autres s’interrogent sur l’impact social, économique et politique du vieillissement de la population et de l’augmentation de l’espérance de vie ou encore, sur l’existence d’une limite biologique à la vie humaine. Dans le cadre de cette thèse, nous analysons la situation démographique des centenaires québécois depuis le début du 20e siècle à partir de données agrégées (données de recensement, statistiques de l’état civil, estimations de population). Dans un deuxième temps, nous évaluons la qualité des données québécoises aux grands âges à partir d’une liste nominative des décès de centenaires des générations 1870-1894. Nous nous intéressons entre autres aux trajectoires de mortalité au-delà de cent ans. Finalement, nous analysons la survie des frères, sœurs et parents d’un échantillon de semi-supercentenaires (105 ans et plus) nés entre 1890 et 1900 afin de se prononcer sur la composante familiale de la longévité. Cette thèse se compose de trois articles. Dans le cadre du premier, nous traitons de l’évolution du nombre de centenaires au Québec depuis les années 1920. Sur la base d’indicateurs démographiques tels le ratio de centenaires, les probabilités de survie et l’âge maximal moyen au décès, nous mettons en lumière les progrès remarquables qui ont été réalisés en matière de survie aux grands âges. Nous procédons également à la décomposition des facteurs responsables de l’augmentation du nombre de centenaires au Québec. Ainsi, au sein des facteurs identifiés, l’augmentation de la probabilité de survie de 80 à 100 ans s’inscrit comme principal déterminant de l’accroissement du nombre de centenaires québécois. Le deuxième article traite de la validation des âges au décès des centenaires des générations 1870-1894 d’origine canadienne-française et de confession catholique nés et décédés au Québec. Au terme de ce processus de validation, nous pouvons affirmer que les données québécoises aux grands âges sont d’excellente qualité. Les trajectoires de mortalité des centenaires basées sur les données brutes s’avèrent donc représentatives de la réalité. L’évolution des quotients de mortalité à partir de 100 ans témoigne de la décélération de la mortalité. Autant chez les hommes que chez les femmes, les quotients de mortalité plafonnent aux alentours de 45%. Finalement, dans le cadre du troisième article, nous nous intéressons à la composante familiale de la longévité. Nous comparons la survie des frères, sœurs et parents des semi-supercentenaires décédés entre 1995 et 2004 à celle de leurs cohortes de naissance respectives. Les différences de survie entre les frères, sœurs et parents des semi-supercentenaires sous observation et leur génération « contrôle » s’avèrent statistiquement significatives à un seuil de 0,01%. De plus, les frères, sœurs, pères et mères des semi-supercentenaires ont entre 1,7 (sœurs) et 3 fois (mères) plus de chance d’atteindre 90 ans que les membres de leur cohorte de naissance correspondante. Ainsi, au terme de ces analyses, il ne fait nul doute que la longévité se concentre au sein de certaines familles. / The recent rise in the number of centenarians within low mortality countries has led to multiple studies conducted on longevity, and more specifically on its determinants and repercussions. Some are trying to identify genes that could be responsible for extreme longevity. Others are studying the social, economic and political impact of the rise in life expectancy and population aging, or questioning themselves about the existence of a biological limit to the human life span. In this thesis, we first study the demographic situation of centenarians from Quebec using aggregated data (census data, vital statistics, and population estimations). Then, we evaluate the quality of Quebec data at the oldest ages using the death records of centenarians belonging to the 1870-1894 birth cohorts. We are particularly interested in the mortality trajectories beyond 100 years old. Finally, we analyze the survival of siblings and parents of a semi-supercentenarians (105 years and over) sample in order to assess the familial component of longevity. The thesis is divided into three articles. In the first article, we study the evolution of the centenarian population from the 1920s in Quebec. With demographic indicators such as the centenarian ratio, the survival probabilities and the maximal age at death, we try to demonstrate the remarkable progress realised in old age mortality. We also analyze the determinants of the increase in the number of centenarians in Quebec. Among the factors identified, the improvement in late mortality is the main determinant of the increase of the number of centenarians in Quebec. The second article deals with the validation of the ages at death of French-Canadian centenarians born in Quebec between 1870-1894. The validation results confirm that Quebec data at the highest ages at death are of very good quality. Therefore, the measure of centenarian mortality based on all death records is representative of the true trends. The evolution of age-specific life table death rates beyond 100 years old assesses the mortality deceleration at the highest ages. Among men and women, the death rates reach a plateau at around 45%. Finally, in the third article, we study the familial predisposition for longevity. We compare the survival probabilities of siblings and parents of semi-supercentenarians deceased between 1995 and 2004 to those of their birth cohort-matched counterparts. The survival differences between the siblings and parents of semi-supercentenarians and their respective birth cohorts are statistically significant at a 0,01% level of significance. The siblings and parents have a 1,7 to 3 times greater probability of survival from age 50 to 90 then members of their respective birth cohorts. These findings support the existence of a substantial familial component to longevity.