This thesis proposes a three-level DC-to-DC converter with capacitive output filter and its extension to single-phase, single-stage, three-level AC-to-DC converter with capacitive output filter. The AC-to-DC converter integrates a three-level boost converter operating in discontinuous conduction mode (DCM) and a three-level half-bridge DC-to-DC converter with capacitive output filter. The steady-state operation of the DC-to-DC converter and AC-to-DC converter with capacitive output filter are studied with phase-shifted gating scheme. The three-level topology reduces the voltage rating of the switches to half of the input voltage. Soft-switching is achieved for switches at different load and input voltage conditions. Boost section of the AC-to-DC converter achieves automatic power factor correction (PFC). At reduced load and higher input voltage conditions, the line current Total Harmonic Distortion (THD) increases with phase-shifted gating scheme. The THD has been reduced by using a complementary PWM gating control in the AC-to-DC converter.

In this thesis I defend the argument that the conventional account of recognition as a process of linguistic intersubjectivity does not adequately explain the occurrence of non-propositional appraisals of the recognition experience such as shame and trust. I present an alternative account consisting of two distinct but related ‘moments’ comprising the encounter between self and other: the standard linguistic form of intersubjectivity, which I term the ‘narrative moment’, and an affective and behavioural intersubjectivity that I term the ‘phenomenal moment’. Through a concise analysis of contemporary recognition theories, classical phenomenology, and contemporary empirical research on the ‘phenomenological self’ I conclude that the success and failure of recognition depends in some instances on mitigating the tension between the self’s ‘narrative’ and ‘phenomenal’ appraisals of the other, or what I term ‘phenomenal dissonance’.

This project aims to identify and "map" the stages of municipal decision making including the development of an Ethical Purchasing Policy by a coalition of community organizations, the approval by the municipal Council, and the implementation of the policy through the municipal departments. The focus is the standardized processes that comprise public participation, public decision making, and public administration. By using institutional ethnography in an innovative manner, this project develops a new way of studying social movements in general, and the social organization of activism in particular that demonstrates that activism is work which is coordinated translocally by text-mediated ruling relations. The results of this project will further the understanding of community members, and municipal Councillors and staff of the social implications of their work and the Ethical Purchasing Policy they helped develop and implement. This research could be used by community organizations and other municipalities considering developing similar policies.

PermuNim is an impartial combinatorial game played on a board of squares where each player takes turns playing in rows and columns of the board which have not been played in, avoiding zero or more permutations. The game comes to an end when neither player can move. The first player unable to move on his or her turn loses the game. Many researchers have investigated combinatorial game theory as well as the idea of permutation pattern avoidance. PermuNim combines both of these ideas. When (12) or (1) is the forbidden permutation in PermuNim, or when the forbidden permutation is 'loses' in size to that of the smallest of the two dimensions of the board, we can say a great deal about the value of the game. For other permutations, the values of the options seem much more chaotic. Even (123) is chaotic as evidenced by our data in the appendix. We investigate the trend for even height boards which are `wide enough' to have options with all odd values and vice versa but we don't believe that this to be true in general. If a PermuNim board is stretched by adding columns, sometimes the value of the position is affected. We find that when any permutation is avoided and t moves have been made, as long at 2m columns are available together, there is a place where any number of columns may be added to the board without affecting the value of the position. We suspect that the number of columns necessary may be much lower for some permutations.

The past decade has seen a transition of Graphics Processing Units (GPUs) from special purpose graphics processors, to general purpose computational accelerators. GPUs have been investigated to utilize their highly parallel architecture to accelerate the computation of the Transmission Line Matrix (TLM) methods in two and three dimensions. The design utilizes two GPU programming languages, Compute Unified Device Architecture (CUDA) and Open Computing Language (OpenCL), to code the TLM methods for NVIDIA GPUs. The GPU accelerated two-dimensional shunt node TLM method (2D-TLM) achieves 340 million nodes per second (MNodes/sec) of performance which is 25 times faster than a commercially available 2D-TLM solver. Initial attempts to adapt the three-dimensional Symmetrical Condensed Node (3D-SCN) TLM method resulted in a peak performance of 47 MNodes/sec or7 times in speed-up. Further efforts to improve the 3D-SCN TLM algorithm, as well as investigating advanced GPU optimization strategies resulted in performances accelerated to 530 MNodes/sec, or 120 times speed-up compared to a commercially available 3D-SCN TLM solver.

It has been frequently postulated that genome or domain-wide histone post-translational modifications induce structural changes to chromatin. Until recently, however, experimental evidence for this hypothesis was lacking. H4 K16 acetylation is the first, and only, of all of the possible post-translational modifications to be directly linked to changes in chromatin conformation. I was interested in clarifying the mechanism by which H4 K16Ac exerts its modulatory effect. To characterize the role of this modification I reconstituted mononucleosomes with H4 K16Ac isolated from chicken erythrocytes by weak cation-exchange HPLC. Analytical ultracentrifuge (AUC) and MgCI2 solubility data suggested that H4 K16Ac structurally relaxes the association of nucleosomal DNA with the histone octamer by weakening intra-nucleosomal DNA-histone electrostatic interaction. Similar to early studies on H4 K16 acetylation, evidence suggests that the phosphorylation of linker histones promotes chromatin decondensation and increases DNA accessibility. In an effort to initiate a study characterizing the structural effects of chromatin fibers containing phosphorylated linker histories, I have optimized a method of purification for nonphosphorylated and monophosphorylated linker histone H5 from erythrocytes of anemic chickens. Preliminary AUC data of oligonucleosomes containing the nonphosphorylated control linker histones (manipulated to the same degree as the experimental monophosphorylated linker histones) showed a salt-dependent sedimentation trend that was consistent with expected values at low ionic concentrations. The purification method described is valuable as it results in a high yield of pure post¬translationally modified H5 product suitable for oligonucleosome reconstitutions. In the third component of this thesis, I describe the creation of a DNA template, Pbsn-208(10), which contains a Rattus norvegicus probasin promoter nucleosome positioning sequence flanked on both sides by 5 tandem repeats of the Lytechinus variegatus nucleosome positioning sequence. Unlike other DNA templates used in the study of chromatin compaction in vitro, the Pbsn-208(10) allows not only the reconstitution of homogenous chromatin fibers but also the differentiation of the middle of the fiber from its flanking ends. Thus, the effects of PTMs on histone-DNA interactions and nucleosome conformation in the center of a chromatin fiber can now be easily investigated. In addition, the Pbsn-208(10) template can help to identify the precise location of H1/H5 within the nucleosome.

The mechanism of the rhodium(I) catalyzed dehydrocoupling of di-n-hexylsilane was investigated by isolating and characterizing products of stoichiometric reactions, by preparing a series of rhodium(I) phosphine precatalysts and silane substrates and measuring catalytic activity, and by observing catalytic reaction mixtures directly using 31P{ 1H} NMR spectroscopy. Catalyst initiation was found to occur via oxidative addition of silane to a rhodium centre, followed by reductive elimination of a chlorosilane generating an unsaturated rhodium hydride complex, the putative active catalyst fragment. The series of precatalysts screened for catalytic activity include [Rh(PPh3)3Cl] (1), [Rh(PPh3)2(µ-Cl)]2 (2). [Rh(dppe)(µ-Cl)]2 (3) [Rh(dppb)(µ-Cl)]2, (4) [Rh(COD)(µ- Cl)]2 (5), [Rh(PPh3)3H] (6), [Rh(PPh3)4H] (7), [Rh(xantphos)(COD)(Cl)]. (8). Of these eight precatalysts the two hydride complexes (6 and 7) displayed the highest catalytic activity. The flexibility of chelating bis(phosphine) ligands was found to be important for catalyst activity. Of the chelating bis(phosphine) rhodium complexes (3, 4, and 8), 4 displayed the highest catalytic activity. The catalyst resting state for all precatalysts containing the monodentate PPh3 ligand was found to be trans-[Rh(PPh3)2LX] when catalytic reactions were observed in situ by 31P{1H} NMR spectroscopy. The substitution and steric bulk of the silane substrate was found to influence reactivity as well. Of the substrates studied, the least bulky primary n-hexylsilane was most reactive. By monitoring the reaction over by 31P{1H} NMR spectroscopy, decomposition of the catalyst was found to involve phosphine dissociation. Decomposition was found to occur more slowly for precatalysts containing chelating bis(phosphine) ligands than for precatalysts containing monodentate phosphine ligands.

Eph receptors and their ephrin ligands play important roles in guiding mouse and Xenopus cranial neural crest (CNC) cells to their destinations. My objective was to determine if Ephs and ephrins also regulate avian CNC pathfinding. By double labeling for Eph or ephrin RNA and a neural crest marker protein, I was able to clearly distinguish neural crest from ectoderm and head mesenchyme and show that avian CNC cells express EphA3, 4, and 7 and EphB 1 and 3 and migrate along pathways bordered by non-neural crest cells expressing ephrin-B 1. Surprisingly, avian CNC cells also express ephrin-B2 and migrate along pathways bordered by non-neural crest cells expressing EphB2. Consistent with these findings, explanted avian CNC cells are labeled by both ephrin-B I and EphB2 Fc fusion proteins. Given the choice between growing out onto substrate-bound fibronectin (FN) or FN plus clustered Fc protein in the stripe assay, these cells show no preference for either condition. Conversely, given the choice between FN or FN plus clustered ephrin-B1 or EphB2 Fc fusion protein, the cells strongly localize to stripes containing only FN. This response is mitigated in the presence of soluble ephrin-B1/Fc or EphB2/Fc, but not in the presence of soluble Fc alone. These findings show that avian CNC cells have a mutually exclusive distribution with non-neural crest cells expressing ephrin-B 1 and EphB2 RNA in situ and are repelled from ephrin-B1 and EphB2 protein in vitro, suggesting that their migration is guided by both forward signaling through a variety of Eph receptors as stimulated by ephrin-B1 and reverse signaling through ephrin-B2 as stimulated by EphB2. I further explore the phylogeny of Ephs and ephrins and show that these genes diversified at different times in evolutionary history, such that the ancestral chordate likely had a single receptor for two different ligands.

The use of hybrid processes med-arb and arb-med continues to grow in both commercial and labour relations contexts. With this growth, there remains a lack of research looking at why a particular hybrid process is chosen or what variables influence individuals to choose one process over another. This exploratory study uses both an online survey of full-time workforce members and semi-structured interviews of experienced hybrid process practitioners to identify and evaluate the variables that influence conflicting parties to choose either med-arb or arb-med. The research findings suggest that two variables, importance of the relationship between the parties and the perceived strength of legal case, are the two greatest indicators of hybrid process selection. Strong support for med-arb is found when disputants place a high value on the importance of their relationship. Arb-med is preferred when relationship is of low importance and strength of legal case is perceived to be high.

I used natural abundances of stable isotopes (δ13C and δ15N) to examine the food web structure of lake zooplankton communities. I focused on modeling isotopic variation with respect to trophic variation (δ15N) and to variation in dietary carbon sources (δ13C). The isotopic patterns suggest that zooplankton food webs have reticulate connections between food chains, and a large diversity of interactions between consumers and their resources. Variation in the δ13C of zooplankton depended on taxonomic identity, body composition, and habitat specialization. In Sooke Lake Reservoir, seasonal variation in the δ13C of zooplankton was mainly related to variation in lipid content and the δ13C of lipids. This has significant consequences for interpreting the pathways of terrestrial carbon through plankton food webs. In Council Lake, variation in the δ13C of zooplankton among taxa was related to habitat specialization, and indicates taxon- specific exploitation of allochthonous resources. Using a cage experiment, I confirmed that δ13C can indicate habitat specialization of zooplankton. Among lakes, my data suggest that zooplankton communities can readily exploit carbon produced below the epilimnion. Large inter- and intra-lake variation in the δ15N of zooplankton suggests significant trophic variation within zooplankton communities. In a year-long study, annual averages of taxa specific δ15N matched our expectations about the feeding ecology of zooplankton. However, short-term variation in the δ15N of herbivorous zooplankton (like Daphnia) was decoupled from seasonal variation in the δ15N of invertebrate predators. This suggests there are multiple food chains within the plankton community (i.e. grazing chain, microbial chain), and that the strength of each food chain may vary among lakes or seasonally within a lake. This seasonal variation in the food web structure of zooplankton has significant consequences for how we model and consider the trophic position of individual fish.