Multirate sampled-data yaw-damper and modal suppression system design

A multirate control law synthesized algorithm based on an infinite-time quadratic cost function, was developed along with a method for analyzing the robustness of multirate systems. A generalized multirate sampled-data control law structure (GMCLS) was introduced. A new infinite-time-based parameter optimization multirate sampled-data control law synthesis method and solution algorithm were developed. A singular-value-based method for determining gain and phase margins for multirate systems was also developed. The finite-time-based parameter optimization multirate sampled-data control law synthesis algorithm originally intended to be applied to the aircraft problem was instead demonstrated by application to a simpler problem involving the control of the tip position of a two-link robot arm. The GMCLS, the infinite-time-based parameter optimization multirate control law synthesis method and solution algorithm, and the singular-value based method for determining gain and phase margins were all demonstrated by application to the aircraft control problem originally proposed for this project

Immunometabolic regulation of atherosclerosis

Ischaemic heart disease and stroke are the most common causes of death in the world, both diseases being manifestations of atherosclerotic cardiovascular disease. Atherosclerosis is a slow process initialized by the retention and accumulation of cholesterol rich lipoproteins in the innermost layer of the artery wall. Activation of an inflammatory response with the recruitment of immune cells lead to a buildup of plaques in the vessel. Both innate immune cells, most prominently macrophages, and adaptive immune cells play important roles in all stages of the development of atherosclerosis. Metabolism is intimately linked with atherosclerosis development. Systemically increased levels of metabolites such as cholesterol and glucose are known risk factors for atherosclerosis. The metabolism in the microenvironment of the atherosclerotic plaque shape the immune response and influence disease progression. Immune cell metabolism of glucose and amino acids have been suggested as possible targets for future therapy. While modern therapies are effective at reducing known risk factors such as hyperlipidemia, considerable risk remains and few therapies for atherosclerosis target the underlying inflammatory mechanisms that drive the disease. In Paper I the effect of indoleamine 2,3-dioxygenase (IDO) mediated tryptophan metabolism on atherosclerosis was investigated. Pharmacological inhibition of IDO with 1-methyl- tryptophan resulted in increased atherosclerotic burden in mice. Furthermore, in vitro data showed that the expression of pro-inflammatory molecules was increased on smooth muscle cells upon IDO inhibition. Treatment with the downstream tryptophan metabolite 3-hydroxyanthranilic acid (3-HAA) reversed both the in vivo and in vitro effects of IDO inhibition. The effects of 3-HAA on lipoprotein metabolism was studied in Paper II. Activity of the transcription factor sterol response element binding protein 2 (SREBP2) was decreased when HepG2 hepatoma cells were treated with 3-HAA. Mice treated with the pharmacological inhibitor of the 3-HAA degrading enzyme 3-HAA oxygenase had less atherosclerotic plaque size and lower plasma lipids. In vitro experiments also showed 3-HAA to be a potent inhibitor of the inflammasome in macrophages. In Paper III we showed that the metabolism of tryptophan is altered in human atherosclerotic disease. Patients with symptoms had an impaired metabolism of tryptophan to kynurenic acid, a metabolite that can induce anti-inflammatory responses, possibly via aryl hydrocarbon receptor activation. In Paper IV we demonstrate that the small molecule dichloroacetate (DCA), a known inhibitor of glycolysis, reduces atherosclerosis lesion size, plasma lipids and reprograms the immune system towards an anti-inflammatory phenotype. We also show that DCA is a potent inhibitor of inflammasome production of IL-1β

Vertical InAs Nanowire Devices and RF Circuits

Recent decades have seen an exponential increase in the functionality of electronic circuits, allowing for continuous innovation, which benefits society. This increase in functionality has been facilitated by scaling down the dimensions of the most important electronic component in modern electronics: the Si-based MOSFET. By reducing the size of the device, more transistors per chip area is possible. Smaller MOSFETs are also faster and more energy-efficient. In state of the art MOSFETs, the key dimensions are only few nanometers, rapidly approaching a point where the current scaling scheme may not be maintained. Research is ongoing to improve the device performance, mainly focusing on material and structural improvements to the existing MOSFET architecture. In this thesis, MOSFETs based on nanowires, are investigated. Taking advantage of the nanowire geometry, the gate can be wrapped all-around the nanowires for excellent control of the channel. The nanowires are made in a high-mobility III-V semiconductor, InAs, allowing for faster electrons and higher currents than Si. This device type is a potential candidate to either replace or complement Si-based MOSFETs in digital and analogue applications. Single balanced down-conversion mixer circuits were fabricated, consisting of three vertically aligned InAs nanowire MOSFETs and two nanowire resistors. These circuits are shown to operate with voltage gain in the GHz-regime. Individual transistors demonstrated operation with gain at several tens of GHz. A method to characterise the resistivity and metal-semiconductor contact quality has been developed, using the transmission line method adapted for vertical nanowires. This method has successfully been applied to InAs nanowires and shown that low-resistance contacts to these nanowires are possible. To optimise the performance of the device and reach as close to intrinsic operation as possible, parasitic capacitances and resistances in the device structure need to be minimised. A novel self-aligned gate-last fabrication method for vertical InAs nanowire transistors has been developed, that allows for an optimum design of the channel and the contact regions. Transistors fabricated using this method exhibit the best DC performance, in terms of a compromise between the normalised transconductance and sub-threshold swing, of any previously reported vertical nanowire MOSFET

Treatment success with continuous positive airway pressure or mandibular advancement splints in non-severe obstructive sleep apnea: A randomized controlled clinical trial on sleep quality, health-related quality of life and clinical predictors of treatment success

Obstructive sleep apnea (OSA) is a respiratory sleep-disorder characterized by repeated breathing cessations due to pharyngeal soft tissue collapse, leading to several medical disorders and possibly premature death. Two commonly used treatment alternatives for OSA are continuous positive airway pressure (CPAP) and mandibular advancement splints (MAS). The overall aim of this randomized clinical trial was to compare CPAP and MAS treatment regarding efficacy, compliance to treatment and the impact on self-reported sleep quality and health-related quality of life (HRQoL) among patients with non-severe OSA. In total, 104 adult patients were randomly allocated to CPAP or MAS treatment and evaluated after 4- and 12 months of treatment. Both intention-to-treat and per protocol analyses were performed for the comparisons between the treatment groups. While the number of residual respiratory events at follow-ups were lower in the CPAP treatment group than in the MAS treatment group, the compliance to MAS treatment was significantly better than compliance to CPAP treatment. The subjective sleep quality and HRQoL were similar between the treatment groups at the follow-up visits. CPAP remains the primary choice of treatment, but the comparable effect on patient-reported outcomes between CPAP and MAS treatment combined with the better compliance to MAS treatment suggests that MAS should be available as a standard treatment option for patients with non-severe OSA. The Friedman tongue position score does not seem to predict the treatment success and compliance to CPAP and MAS treatment in patients with non-severe OSA.Obstruktiv søvnapné (OSA) er en søvnlidelse som karakteriseres av gjentatte pustestans som følge av mykvevskollaps i svelget. Dette fører økt risikoen for alvorlig sykdom og tidlig død. To vanlige behandlingsalternativ for OSA er kontinuerlig luftveisovertrykk (CPAP) og søvnapnéskinner (MAS). Målet med denne randomiserte kliniske studien var å sammenligne behandling med CPAP og MAS med hensyn til bedring i antall pustestans, behandlingsetterlevelse og virkningen fra behandlinga på opplevd søvnkvalitet og helserelatert livskvalitet blant pasienter med ikke-alvorlig OSA. Totalt 104 voksne pasienter ble tilfeldig satt til behandling med CPAP eller MAS og fulgt opp med kontroller etter 4- og 12 måneder. Både «intention-to-treat-analyser» og «per protocol-analyser» ble utført ved sammenligning av behandlingsgruppene. Mens CPAP-behandlinga var klart best til å redusere antallet pustestans, var etterlevelsen til MAS-behandling betydelig bedre enn ved CPAP-behandling. Det var ingen forskjell i opplevd søvnkvalitet og helserelatert livskvalitet mellom CPAP- og MAS-gruppene etter 12 måneder med behandling. Det kan konkluderes med at søvnkvalitet og helserelatert livskvalitet etter 12 måneder med CPAP- og MAS-behandling var lik, til tross for stor forskjell i antall pustestans ved behandling. CPAP er fortsatt førstevalg ved behandling av ikke-alvorlig OSA, men effekten på pasient-rapportert søvnkvalitet og helserelatert livskvalitet sammen med god behandlingsetterlevelse tilsier at MAS burde være et tilgjengelig behandlingsalternativ til CPAP. Videre kan det se ut til at Friedmans skår for tungeposisjon ikke kan predikere vellykkethet og etterlevelse i behandling med CPAP eller MAS blant pasienter med ikke-alvorlig OSA

Svalbard as a Motif and a Place of Artistic Exploration: Insights from an Art Gallery Director

The article outlines the history of artists’ exploration of Svalbard as a motif, and then proceeds to describe a number of more recent art practices by the artists relating to Svalbard in the new millennium. The article traces the artists’ development from being supporters of research by providing visual material, to becoming researchers in their own right

The costs of illiteracy in South Africa

In South Africa there has been a surge in publicly funded adult literacy education in recent years. There is a recognition that for the effective monitoring of adult literacy, direct measures of literacy are required. Grade attainment, self-reported ability to read and behavioural variables relating to, for instance, reading habits produce vastly different measures of adult literacy in South Africa. It is noteworthy that self-reported values change over time as people’s perceptions of what consitutes literacy shifts. A 75% literacy rate is arguably a plausible figure, though the absence of a direct measure is problematic. An education production function suggests that literacy-related parent behaviour, independently of parent years of education, influences performance of learners in school. In a multivariate employment model, self-reported literacy is a statistically significant predictor of being employed. In a cross-country growth model, poor quality schooling emerges as the variable requiring the most urgent policy attention to sustain and improve South Africa’s economic development. Both microeconomic and macroeconomic estimates suggest that with a more typical level of school performance South Africa’s GDP would be 23% to 30% higher than it currently is.Literacy, Illiteracy, South Africa, Education production function, Economic growth

Der Fachverband der Historiker und sein historischer Ort.: Dimensionen einer vergleichenden Verbandsgeschichte

The history of the German Historical Association is to evaluate and to write appropriate only in comparison with other scientific associations and academic cultures. This issue is dedicated to this transdisciplinary comparison of scientific associations and presents essays on the development of the German Sociological Association (Deutsche Gesellschaft für Soziologie), the German Association of German Studies (Deutscher Germanistenverband) and the American Studies Association