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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
751

Live Load Testing and Analysis of the Southbound Span of U.S. Route 15 over Interstate-66

Collins, William Norfleet 25 August 2010 (has links)
more funding must be allocated for their rehabilitation or replacement. The Federal Highway Administration's (FHWA) Long-Term Bridge Performance (LTBP) Program has been developed to help bridge stakeholders make the best decisions concerning the allocation of these funds. This is done through the use of high quality data obtained through numerous testing processes. As part of the LTBP Pilot Program, researchers have performed live load tests on the U.S. Route 15 Southbound bridge over Interstate-66. The main performance and behavior characteristics focused on are service strain and deflection, wheel load distribution, dynamic load allowance, and rotational behavior of bridge bearings. Data from this test will be used as a tool in developing and refining a plan for long-term bridge monitoring. This includes identifying the primarily loaded girders and their expected range of response under ambient traffic conditions. Information obtained from this test will also aid in the refinement of finite element models by offering insight into the performance of individual bridge components, as well as overall global behavior. Finally, the methods and results of this test have been documented to allow for comparison with future testing of this bridge, which will yield information concerning the changes in bridge behavior over time. / Master of Science
752

HPA Axis Responsiveness Associates with Central Serotonin Transporter Availability in Human Obesity and Non-Obesity Controls

Schinke, Christian, Rullmann, Michael, Luthardt, Julia, Drabe, Mandy, Preller, Elisa, Becker, Georg A., Patt, Marianne, Regenthal, Ralf, Zientek, Franziska, Sabri, Osama, Bergh, Florian Then, Hesse, Swen 31 July 2024 (has links)
Background: Alterations of hypothalamic–pituitary–adrenal (HPA) axis activity and serotonergic signaling are implicated in the pathogenesis of human obesity and may contribute to its metabolic and mental complications. The association of these systems has not been investigated in human obesity. Objective: To investigate the relation of HPA responsiveness and serotonin transporter (5-HTT) availability in otherwise healthy individuals with obesity class II or III (OB) compared to non-obesity controls (NO). Study participants: Twenty-eight OB (21 females; age 36.6 10.6 years; body mass index (BMI) 41.2 5.1 kg/m2) were compared to 12 healthy NO (8 females; age 35.8 7.4 years; BMI 22.4 2.3 kg/m2), matched for age and sex. Methods: HPA axis responsiveness was investigated using the combined dexamethasone/corticotropin-releasing hormone (dex/CRH) test, and curve indicators were derived for cortisol and adrenocorticotropic hormone (ACTH). The 5-HTT selective tracer [11C]DASB was applied, and parametric images of the binding potentials (BPND) were calculated using the multilinear reference tissue model and evaluated by atlas-based volume of interest (VOI) analysis. The self-questionnaires of behavioral inhibition system/behavioral activation system (BIS/BAS) with subscales drive, fun-seeking and reward were assessed. Results: OB showed significant positive correlations of ACTH curve parameters with overall 5-HTT BPND (ACTHAUC: r = 0.39, p = 0.04) and 5-HTT BPND of the caudate nucleus (ACTHAUC: r = 0.54, p = 0.003). In NO, cortisol indicators correlated significantly with BPND in the hippocampus (cortisolAUC: r = 0.59, p = 0.04). In OB, BAS reward was inversely associated with the ACTHAUC (r = 0.49, p = 0.009). Conclusion: The present study supports a serotonergic-neuroendocrine association, which regionally differs between OB and NO. In OB, areas processing emotion and reward seem to be in-volved. The finding of a serotonergic HPA correlation may have implications for other diseases with dysregulated stress axis responsiveness, and for potential pharmacologic interven-tions.
753

Kan Yoga Nidra påverka sömn? : En systematisk litteraturstudie

Hall, Carina January 2024 (has links)
Bakgrund: Sömnproblem är ett utbrett problem och är oftast en del av vissa livsstilssituationer där jobb, familjeliv och sjukdom kan påverka sömnen negativt. Fysisk aktivitet är en strategi för att förbättra sömnen, men vid tillfällen där aktiv rörelse inte är möjlig kan avslappningstekniker användas. Yoga nidra, även kallad yogisk sömn, är en guidad meditationsteknik som involverar många olika avslappningstekniker. En effekt av yoga nidra tycks vara ökad parasympatisk aktivitet och minskad sympatisk aktivitet. Syfte: Syftet med studien var att undersöka yoga nidras påverkan på sömnen på vuxna individer.                                                                                                          Metod: En systematisk litteraturstudie baserad på vetenskapliga artiklar publicerade 2019-2024. Databaserna PubMed och Web of Science användes för litteratursökningen. Resultat: Sex artiklar mötte inklusionskriterierna. Samtliga studier var experimentella. Fem av studierna visade på signifikant förbättrad sömn efter upprepad intervention. En studie gav oförändrad effekt efter en yoga nidra session.                                  Slutsats: Resultatet från litteraturstudien tyder på att yoga nidra kan inverka positivt på sömnen om interventionen utförs kontinuerligt. Dock rådde heterogenitet bland artiklarna gällande studiens kvalitet, population och interventionens längd, vilket försvårar tolkning av resultat. Bättre och mer enhetliga studier samt fler deltagare behövs för att kunna påvisa ett samband. / Background: Sleep problems are widespread and are usually part of certain lifestyle situations where work, family life and illness can affect sleep negatively. Physical activity is one strategy to improve sleep, but relaxation techniques can be used when active movement is not possible. Yoga Nidra, or yogic sleep, is a guided meditation technique that involves many different relaxation methods. One effect of yoga nidra appears to be increased parasympathetic activity and decreased sympathetic activity. Aims: The study aimed to examine the effect of yoga nidra on sleep in adults. Methods: A systematic literature study based on scientific articles published 2019-2024. The literature search was done using Pub Med and Web of Science databases. Results: Six articles met the inclusion criteria and were included in the study. All studies were experimental. Five of the studies showed significantly improved sleep after repeated intervention. One study found an unchanged effect after only one yoga nidra session. Conclusions: The results from the literature study indicate that yoga nidra may have a positive effect on sleep if the intervention is carried out over a period of time. However, there was heterogeneity among the articles regarding the study quality, population and intervention length, making it difficult to assess the results. Better and more unitary studies and more participants are needed to determine a connection.
754

(Not) Drawing The Line: Technology Reexamined

Liguori, Elizabeth Angela 07 June 2017 (has links)
(Not) Drawing The Line: Technology Re-examined is the culmination of interdisciplinary research exploring the nature of materiality and process in the fields of art, science, and technology. Exploration and experimentation in these diverse disciplines have helped to illuminate many of the ideas and concepts that have guided the overall research process. These explorations have also honed the ability to critically examine how technology is perceived and represented, post-internet.   This document illustrates the processes involved in the conception and creation of a body of work manifested through visual and technological problem solving, investigative research of materials and technologies, and the fundamental concerns of art, technology, form and pattern. These empirical areas of research are punctuated by literary texts on the philosophy of art and technology that have informed many of the visual comparisons represented. This body of evidence is an exploration of the idea that the evolution of technological developments can often be attributed to the creation of art through the heuristic experimentation and visual explorations of the artist. / Master of Fine Arts / (Not) Drawing The Line: Technology Re-examined is the result of exploration and research in the areas of studio art, science, and technology. Many of the ideas and concepts presented in this documentation are a result of curiosity-driven research which uses materials and processes to help form connections across disciplines. In most examples, the materials used are common or familiar items such as the #2 pencil, reflective surfaces such as a mirror, or clay used for ceramics. The intention behind the work documented in this thesis is to help the viewer look at these everyday materials in a different way than their common use suggests through visual comparisons and wordplay. Its goal is to suggest that a new use or discovery may be presented in common materials and that solutions to complicated problems could be found right under our noses, so to speak. at its core, it is a commentary on technology, its uses, and perceptions during our current, post-internet place in history
755

Numerical models for tidal turbine farms

Shives, Michael Robert 22 June 2017 (has links)
Anthropogenic climate change is approaching predicted tipping points and there is an urgent need to de-carbonize energy systems on a global scale. Generation technologies that do not emit greenhouse gas need to be rapidly deployed, and energy grids need to be updated to accommodate an intermittent fluctuating supply. Rapidly advancing battery technology, cost reduction of solar and wind power and other emerging generation technologies are making the needed changes technically and economically feasible. Extracting energy from fast-flowing tidal currents using turbines akin to those used in wind farms, offers a reliable and predictable source of GHG free energy. The tidal power industry has established the technical feasibility of tidal turbines, and is presently up-scaling deployments from single isolated units to large tidal farms containing many turbines. However there remains significant economic uncertainty in financing such projects, partially due to uncertainty in predicting the long-term energy yield. Since energy yield is used in calculating the project revenue, it is of critical importance. Predicting yield for a prospective farm has not received sufficient attention in the tidal power literature. this task has been the primary motivation for this thesis work, which focuses on establishing and validating simulation-based procedures to predict flows through large tidal farms with many turbines, including the back effects of the turbines. This is a challenging problem because large tidal farms may alter tidal flows on large scales, and the slow-moving wake downstream of each rotor influences the inflow to other rotors, influencing their performance and loading. Additionally, tidal flow variation on diurnal and monthly timescales requires long-duration analysis to obtain meaningful statistics that can be used for forecasting. This thesis presents a hybrid simulation method that uses 2D coastal flow simulations to predict tidal flows over long durations, including the influence of turbines, combined with higher-resolution 3D simulations to predict how wakes and local bathymetry influence the power of each turbine in a tidal farm. The two simulation types are coupled using a method of bins to reduce the computational cost within reasonable limits. The method can be used to compute detailed 3D flow fields, power and loading on each turbine in the farm, energy yield and the impact of the farm on tidal amplitude and phase. The method is demonstrated to be computationally tractable with modest high-performance computing resources and therefore are of immediate value for informing turbine placement, comparing turbine farm-layout cases and forecasting yield, and may be implemented in future automated layout optimization algorithms. / Graduate
756

Der Einfluss von Ziprasidon auf den Schlaf und die Kortisolexkretion / The influence of ziprasidone on sleep and cortisol excretion

Neumann, Anna-Catharina Hilda 23 April 2008 (has links)
No description available.
757

Effects of periconceptional undernutrition and twinning on ovine pregnancy

Rumball, Christopher William Henry January 2008 (has links)
Events around conception such as maternal undernutrition and twinning may have effects on offspring physiology and disease risk in adulthood. Periconceptional undernutrition alters offspring physiology and adult pathology without affecting birth size, while twinning affects birth size and physiology but with inconsistent effects on adult pathology. We investigated the effects of these two periconceptional events and their interaction on maternal cardiovascular adaptation to pregnancy and fetal growth, physiology and endocrinology in late gestation in sheep. Pre and/or postconception undernutrition resulted in increased uterine blood flow in late gestation, but no change in maternal blood volume. Preconception undernutrition alone resulted in a relatively large placenta with a small, slow-growing fetus in late gestation. In contrast, postconception undernutrition alone resulted in a fetus with rapid late-gestation growth that was maintained through a maternal fast. Fetuses of ewes undernourished throughout both periods were similar in growth rate and size to controls. Maternal fasting also demonstrated that plasma levels of C-type natriuretic peptide are acutely and independently regulated by nutrient supply in mother and fetus. Fetuses of ewes undernourished both pre- and postconception had increased glucose disposal following a glucose challenge. Hypothalamic-pituitary-adrenal axis tests in these fetuses showed decreased pituitary adrenocorticotropin hormone response to direct stimulation but increased adrenal response to decreased cortisol negative feedback. Twin fetuses grew more slowly in late gestation than singletons. Twins also had a smaller insulin response to arginine and a greater insulin response to glucose, but periconceptional undernutrition abolished this difference. Twins had suppressed baseline hypothalamic-pituitary-adrenal axis function and decreased adrenal sensitivity compared to singletons, but increased fetal pituitary adrenocorticotropin hormone response to direct stimulation and decreased cortisol negative feedback. These studies suggest that firstly, fetal size is a poor reflection of fetal growth trajectory, physiology and endocrinology. Secondly, pre- and postconception undernutrition affect late-gestation fetal growth in different ways, while undernutrition in both periods alters fetal endocrine status in late gestation. Thirdly, the biology of twin fetal development is fundamentally different from that of singletons, which may explain the inconsistency of the relationship between birth weight and adult disease risk in twins. / Auckland Medical Research Foundation, Health Research Council of New Zealand
758

Effects of periconceptional undernutrition and twinning on ovine pregnancy

Rumball, Christopher William Henry January 2008 (has links)
Events around conception such as maternal undernutrition and twinning may have effects on offspring physiology and disease risk in adulthood. Periconceptional undernutrition alters offspring physiology and adult pathology without affecting birth size, while twinning affects birth size and physiology but with inconsistent effects on adult pathology. We investigated the effects of these two periconceptional events and their interaction on maternal cardiovascular adaptation to pregnancy and fetal growth, physiology and endocrinology in late gestation in sheep. Pre and/or postconception undernutrition resulted in increased uterine blood flow in late gestation, but no change in maternal blood volume. Preconception undernutrition alone resulted in a relatively large placenta with a small, slow-growing fetus in late gestation. In contrast, postconception undernutrition alone resulted in a fetus with rapid late-gestation growth that was maintained through a maternal fast. Fetuses of ewes undernourished throughout both periods were similar in growth rate and size to controls. Maternal fasting also demonstrated that plasma levels of C-type natriuretic peptide are acutely and independently regulated by nutrient supply in mother and fetus. Fetuses of ewes undernourished both pre- and postconception had increased glucose disposal following a glucose challenge. Hypothalamic-pituitary-adrenal axis tests in these fetuses showed decreased pituitary adrenocorticotropin hormone response to direct stimulation but increased adrenal response to decreased cortisol negative feedback. Twin fetuses grew more slowly in late gestation than singletons. Twins also had a smaller insulin response to arginine and a greater insulin response to glucose, but periconceptional undernutrition abolished this difference. Twins had suppressed baseline hypothalamic-pituitary-adrenal axis function and decreased adrenal sensitivity compared to singletons, but increased fetal pituitary adrenocorticotropin hormone response to direct stimulation and decreased cortisol negative feedback. These studies suggest that firstly, fetal size is a poor reflection of fetal growth trajectory, physiology and endocrinology. Secondly, pre- and postconception undernutrition affect late-gestation fetal growth in different ways, while undernutrition in both periods alters fetal endocrine status in late gestation. Thirdly, the biology of twin fetal development is fundamentally different from that of singletons, which may explain the inconsistency of the relationship between birth weight and adult disease risk in twins. / Auckland Medical Research Foundation, Health Research Council of New Zealand
759

Effects of periconceptional undernutrition and twinning on ovine pregnancy

Rumball, Christopher William Henry January 2008 (has links)
Events around conception such as maternal undernutrition and twinning may have effects on offspring physiology and disease risk in adulthood. Periconceptional undernutrition alters offspring physiology and adult pathology without affecting birth size, while twinning affects birth size and physiology but with inconsistent effects on adult pathology. We investigated the effects of these two periconceptional events and their interaction on maternal cardiovascular adaptation to pregnancy and fetal growth, physiology and endocrinology in late gestation in sheep. Pre and/or postconception undernutrition resulted in increased uterine blood flow in late gestation, but no change in maternal blood volume. Preconception undernutrition alone resulted in a relatively large placenta with a small, slow-growing fetus in late gestation. In contrast, postconception undernutrition alone resulted in a fetus with rapid late-gestation growth that was maintained through a maternal fast. Fetuses of ewes undernourished throughout both periods were similar in growth rate and size to controls. Maternal fasting also demonstrated that plasma levels of C-type natriuretic peptide are acutely and independently regulated by nutrient supply in mother and fetus. Fetuses of ewes undernourished both pre- and postconception had increased glucose disposal following a glucose challenge. Hypothalamic-pituitary-adrenal axis tests in these fetuses showed decreased pituitary adrenocorticotropin hormone response to direct stimulation but increased adrenal response to decreased cortisol negative feedback. Twin fetuses grew more slowly in late gestation than singletons. Twins also had a smaller insulin response to arginine and a greater insulin response to glucose, but periconceptional undernutrition abolished this difference. Twins had suppressed baseline hypothalamic-pituitary-adrenal axis function and decreased adrenal sensitivity compared to singletons, but increased fetal pituitary adrenocorticotropin hormone response to direct stimulation and decreased cortisol negative feedback. These studies suggest that firstly, fetal size is a poor reflection of fetal growth trajectory, physiology and endocrinology. Secondly, pre- and postconception undernutrition affect late-gestation fetal growth in different ways, while undernutrition in both periods alters fetal endocrine status in late gestation. Thirdly, the biology of twin fetal development is fundamentally different from that of singletons, which may explain the inconsistency of the relationship between birth weight and adult disease risk in twins. / Auckland Medical Research Foundation, Health Research Council of New Zealand
760

Effects of periconceptional undernutrition and twinning on ovine pregnancy

Rumball, Christopher William Henry January 2008 (has links)
Events around conception such as maternal undernutrition and twinning may have effects on offspring physiology and disease risk in adulthood. Periconceptional undernutrition alters offspring physiology and adult pathology without affecting birth size, while twinning affects birth size and physiology but with inconsistent effects on adult pathology. We investigated the effects of these two periconceptional events and their interaction on maternal cardiovascular adaptation to pregnancy and fetal growth, physiology and endocrinology in late gestation in sheep. Pre and/or postconception undernutrition resulted in increased uterine blood flow in late gestation, but no change in maternal blood volume. Preconception undernutrition alone resulted in a relatively large placenta with a small, slow-growing fetus in late gestation. In contrast, postconception undernutrition alone resulted in a fetus with rapid late-gestation growth that was maintained through a maternal fast. Fetuses of ewes undernourished throughout both periods were similar in growth rate and size to controls. Maternal fasting also demonstrated that plasma levels of C-type natriuretic peptide are acutely and independently regulated by nutrient supply in mother and fetus. Fetuses of ewes undernourished both pre- and postconception had increased glucose disposal following a glucose challenge. Hypothalamic-pituitary-adrenal axis tests in these fetuses showed decreased pituitary adrenocorticotropin hormone response to direct stimulation but increased adrenal response to decreased cortisol negative feedback. Twin fetuses grew more slowly in late gestation than singletons. Twins also had a smaller insulin response to arginine and a greater insulin response to glucose, but periconceptional undernutrition abolished this difference. Twins had suppressed baseline hypothalamic-pituitary-adrenal axis function and decreased adrenal sensitivity compared to singletons, but increased fetal pituitary adrenocorticotropin hormone response to direct stimulation and decreased cortisol negative feedback. These studies suggest that firstly, fetal size is a poor reflection of fetal growth trajectory, physiology and endocrinology. Secondly, pre- and postconception undernutrition affect late-gestation fetal growth in different ways, while undernutrition in both periods alters fetal endocrine status in late gestation. Thirdly, the biology of twin fetal development is fundamentally different from that of singletons, which may explain the inconsistency of the relationship between birth weight and adult disease risk in twins. / Auckland Medical Research Foundation, Health Research Council of New Zealand

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