Hepatocytes exhibit a regulatory volume decrease (RVD) during hypotonic shock, which comprises loss of intracellular K+ and Cl- accompanied by hyperpolarization of transmembrane potential (Vm) due to an increase in membrane K+ conductance, (GK). To examine hepatocyte K+ homeostasis during RVD, double-barrel, K+-selective microelectrodes were used to measure changes in steady-state intracellular K+ activity (aKi) and Vm during hyposmotic stress. Cell water volume change was evaluated by measuring changes in intracellular tetramethylammonium (TMA+). Liver slices were superfused with modified Krebs physiological salt solution. Hyposmolality (0.8×300 mosm) was created by a 50 m m step-decrease of external sucrose concentration. Hepatocyte Vm hyperpolarized by 19 mV from -27 ± 1 to -46 ± 1 mV and aKidecreased by 14% from 91 ± 4 to 78 ± 4 m m when slices were exposed to hyposmotic stress for 4-5 min. Both Vm and aKireturned to control level after restoring isosmotic solution. In paired measurements, hypotonic stress induced similar changes in Vm and aKiboth control and added ouabain (1 m m) conditions, and these values returned to their control level after the osmotic stress. In another paired measurement, hypotonic shock first induced an 18-mV increase in Vm and a 15% decrease in aKiin control condition. After loading hepatocytes with TMA+, the same hypotonic shock induced a 14-mV increase in Vm and a 14% decrease in aTMAi. This accounted for a 17% increase of intracellular water volume, which was identical to the cell water volume change obtained when aKiwas used as the marker. Nonetheless, hyposmotic stress-induced changes in Vm and aKiwere blocked partly by Ba2+ (2 m m). We conclude that (i) hepatocyte Vm increases and aKidecreases during hypotonic shock; (ii) the changes in hepatocyte Vm and aKiduring and after hypotonic shock are independent of the Na+-K+ pump; (iii) the decrease in aKiduring hypotonic stress results principally from hepatocyte swelling.

Construction of pavements requires the subgrades - which are the foundation of the structure, to be capable of supporting traffic loads that would be applied onto them. In the case that the subgrades are unable to support the structure, failure would occur. The subgrade being in-situ soil can be of poor quality if not properly constructed or improved if necessary. In Canada, the eastern region precisely Ontario and Quebec, is dominated by sensitive marine clays which when disturbed lose their strength drastically making them a geotechnical hazard. The soil's high sensitivity causes this behavior it poses. Therefore, to construct pavements in this type of soil, improvement techniques are required. One such is lime stabilization which improves the engineering properties of the soil. Research on the stabilization of sensitive marine clay in Canada has been conducted to a certain extent showing the effectiveness of the process in improving the soil's poor engineering properties. However, during the process of stabilization, the thermal (T), hydraulic (H), mechanical (M) and chemical (C) processes and interactions that occur influence the behavior of the stabilized clay. Environmental stresses such as moisture and temperature are also known to affect the coupled processes that occur. However, these coupled processes and their impact on the stabilized clay are not well known and understood. The goal of the research was to therefore, conduct various column experiments and monitoring to determine the evolution of the coupled THMC processes under normal curing and when daily thermal cycles were applied to the treated and untreated clay. Various columns were prepared in the laboratory to accommodate the compacted treated and untreated sensitive marine clay for monitoring over 28 days. In addition, columns from which samples for extensive geotechnical testing were collected, were prepared. The soils' strength and hydraulic conductivity were determined through testing while the suction, electrical conductivity and temperature evolution were determined by use of sensors placed within the columns. The developed mechanical properties of the soil were significantly improved by use of lime. This development of mechanical properties was further enhanced when the daily thermal cycles were applied to the soil due to increased curing temperature stimulated. In addition, to temperature and chemical reactions, it was observed that the hydraulic properties also contributed to the developed soil strength. The strongly coupled THMC processes were thus, observed during the treatment of the clay with lime. The results obtained will therefore, contribute to a better understanding of the coupled THMC processes that occur when sensitive marine clay is treated with lime. It will further contribute to cost effectively designing pavements in regions with sensitive marine clays or similar.

Aliasing is a potential source of problems in software development and can, for example,lead to data races in concurrent programs. More recent programming languages includealiasing control in order to catch more errors at compile time. However, this does notexist for most widely-used languages.LaCasa introduces aliasing control to Scala. LaCasa is a type system and program-ming model that provides lightweight unique and affine (consumable) object referencesin Scala. The unique references provided by LaCasa enable messages to be passed effi-ciently by reference. They also guarantee a deep-copy semantic which makes it possible tomore easily port a concurrent program from running on a single machine to being dis-tributed and running on a large cluster of machines.One aspect that makes LaCasa inconvenient to use is the fact that code needs to bewritten in an explicit continuation-passing style (CPS), different to how code is usuallywritten, which makes programs harder to write, understand and maintain.This project presents a flow-sensitive version of LaCasa which avoids the use of con-tinuations. Flow-sensitivity is achieved by adding an extra compiler phase that performsa static analysis, enforcing LaCasa’s type-checking rules. The flow-sensitive version wasevaluated by measuring the code complexity compared to the original flow-insensitiveLaCasa. A few case studies were performed, as part of the evaluation, to show how flow-sensitive LaCasa can be used to extend LaCasa into other fields of application.The evaluation showed that a flow-sensitive LaCasa can reduce the complexity of ap-plications using LaCasa. It allows programmers to write code in a more usual way whichmakes LaCasa easier to use. / Aliasing är en potentiell källa till problem inom mjukvaruutveckling och can till exempelleda till data races i samtidiga program. Nyare programmeringsspråk inkluderar aliasing-kontroller för att kunna fånga fel vid kompilering. Sådana kontroller existerar inte för deflesta utbredda språken.LaCasa introducerar aliasing-kontroll till Scala. LaCasa är ett typsystem och program-meringsmodell som tillhandahåller unika och affina (förbrukningsbara) objektreferenser iScala. De unika references som tillhandahålls av LaCasa gör det möjligt att effektivt skic-ka meddelanden via referenser. De garanterar också en djup-kopierings-semantik som gördet möjligt att mer enkelt konvertera ett samtidigt program från att köras på en endamaskin till att distribueras och köras på ett stort maskinkluster.En aspekt som gör LaCasa obekvämt att använda är att kod måste skrivas i en ex-plicit continuation-passing-stil (CPS), olik det vanliga sättet att skriva kod, som gör pro-gram svårare att skriva, förstå och underhålla.Det här projektet presenterar en flödeskänslig version av LaCasa som unviker an-vändningen av continuations. Flödeskänslighet uppnås genom att lägga till en extra kom-pileringsfas som utför en statisk analys som upprätthåller LaCasas typ-regler. Den flö-deskänsliga versionen utvärderades genom att mäta kodkomplexitet jämfört med denursprungliga flödesokänsliga LaCasa. Några fallstudier utfördes, som en del av utvär-deringen, för att visa hur flödekänsliga LaCasa kan användas för att utöka LaCasa tillandra användningsområden.Utvärdering visade att ett flödeskänsligt LaCasa kan reducera komplexiteten hos ap-plikationer som använder LaCasa. Det tillåter programmerare att skriva kod på ett mervanligt sätt som gör LaCasa enklare att använda.

Light as a “green” source of energy has become increasingly attractive throughout the past century and has shown versatility for the application of activating chemical reactions. Compared with traditional energy sources, it provides a more direct, selective and controllable method. My PhD study was focused on the study of photochemistry of organic materials in two different systems. The first system is regarding reversible photoacids which generate protons on irradiation. With the aim of systematically studying these novel types of long lived photoacids, a series of photoacids was designed, synthesized and whose chemical mechanism was thoroughly investigated. This type of photoacid changes from a weak acid to a strong acid with a pH change of several units, which achieves nearly complete proton dissociation upon visible light irradiation. The whole process is reversible and the half-life of the proton-dissociation state is long enough to be used in many applications. Besides fundamental studies, different applications based on this type of photoacids were also completed. An esterification reaction was catalyzed and the volume of a pH-sensitive polymer was altered due to the large amount of photo generated protons from this photoacid. A reversible electrical conductivity change of polyaniline (PANI) was also achieved by doping with this reversible photoacid. In order to induce a large conductivity increase, an irreversible photoacid generator (PAG) was embedded in a novel PANI/PAG/PVA novel composition. In this system, Poly (vinyl alcohol) (PVA) forms a hydrogen-bonding network to facilitate proton transfer between the PAG and PANI. A final electrical conductivity of 10-1 S cm-1 was successfully achieved after irradiation. The second system in which I explored photochemistry of organic molecules concerns Photoretro-Diels-Alder (PrDA) reactions and a variety of Diels-Alder (DA) adducts were designed for these studies. UV light was used to trigger the retro-Diels-Alder reactions. Quantum yield of iv each DA adducts was investigated. This revealed that the photo-reactivity of this process depends on the electron-donating ability of the diene and the electron-withdrawing ability of the dienophile component. Mechanistic studies of this PrDA reaction reveal that a charge-separated intermediate is generated from a singlet excited state. This was applied to an unsaturated cyclic α-diketones (DKs), which underwent PrDA reactions and generated anthracene derivatives and carbon monoxide (CO), which itself plays profound and important roles in biological systems. These unsaturated cyclic α-diketones (DKs) encapsulated in micelles are effective CO-releasing molecules (CORMs) and are capable of carrying and releasing CO in cellular systems. This novel type of organic CORMs has potentially low toxicity and generates fluorescence, which provides a useful tool for the study of the biological functions of CO.

A new pressure-measurement technique which employs the tools of molecular spectroscopy has recently received considerable attention in the fluid mechanics community. Measurements are made via oxygen-sensitive molecules attached to the surface of interest as a coating, or paint. The pressure-sensitive-paint (PSP) technique is now commonly used in stationary wind-tunnel tests; this thesis presents the extension of the technique to advanced turbomachinery applications. New pressure- and temperature-sensitive paints (TSPs) have been developed for application to a state-of-the-art transonic compressor where pressures up to 2 atm and surface temperatures up to 140° C are expected for the first-stage rotor. PSP and TSP data has been acquired from the suction surface of the first-stage rotor of a transonic compressor operating at its peak-efficiency condition. The shock structure is clearly visible in the pressure image, and visual comparison to the corresponding computational fluid dynamics (CFD) prediction shows qualitative agreement to the PSP data. / Master of Science

A central goal of the robotics community is to develop general optimization algorithms for producing high-performance dynamic behaviors in robot systems. This goal is challenging because many robot control tasks are characterized by significant stochasticity, high-dimensionality, expensive evaluations, and unknown or unreliable system models. Despite these challenges, a range of algorithms exist for performing efficient optimization of parameterized control policies with respect to average cost criteria. However, other statistics of the cost may also be important. In particular, for many stochastic control problems, it can be advantageous to select policies based not only on their average cost, but also their variance (or risk). In this thesis, I present new efficient global and local risk-sensitive stochastic optimization algorithms suitable for performing policy search in a wide variety of problems of interest to robotics researchers. These algorithms exploit new techniques in nonparameteric heteroscedastic regression to directly model the policy-dependent distribution of cost. For local search, learned cost models can be used as critics for performing risk-sensitive gradient descent. Alternatively, decision-theoretic criteria can be applied to globally select policies to balance exploration and exploitation in a principled way, or to perform greedy minimization with respect to various risk-sensitive criteria. This separation of learning and policy selection permits variable risk control, where risk sensitivity can be flexibly adjusted and appropriate policies can be selected at runtime without requiring additional policy executions. To evaluate these algorithms and highlight the importance of risk in dynamic control tasks, I describe several experiments with the UMass uBot-5 that include learning dynamic arm motions to stabilize after large impacts, lifting heavy objects while balancing, and developing safe fall bracing behaviors. The results of these experiments suggest that the ability to select policies based on risk-sensitive criteria can lead to greater flexibility in dynamic behavior generation.

There are many approaches taken by teachers in order to effectively teach students the information they will need to be successful. One of these approaches is that of brain-based instruction. No one single definition is the same as another when it comes to brain-based teaching and learning. Definitions may include incorporating music and movement into lessons, using techniques to reach both hemispheres of the brain, and differentiating instruction to teach to the needs of the individual students. This study takes a closer look at the perspective of teachers when it comes to what brain-based instruction strategies are. Teachers were given a survey to voice their opinions about brain-based instruction and how they incorporate it into their classrooms. This study gathered information about how teachers perceive and understand brain-based instruction. The use of brain-based instruction is quickly becoming vital to the education field. Understanding more about it will help teachers effectively teach students.

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