The maintenance of dynamic chromatin structures is critical for the proper regulation of cellular activities. The plasticity of chromatin structures can be mediated in several ways, two of which include the incorporation of histone variants and the activities of trans-acting factors. In this dissertation, biochemical methods were used to determine the effects of the histone variant H2A.Z or the methyl-CpG binding protein 2 (MeCP2) on the structural composition of native chromatin. Early, independent biophysical studies of the stability of reconstituted H2A.Z chromatin structures yielded contradictory results. As these studies used H2A.Z expressed as a recombinant protein, it was possible that the absence of any essential folding or post-translational modifications (PTMs) may have been responsible for the diametric findings. To resolve this issue, the stability of various native chromatin structures containing H2A.Z was determined. Using gel filtration chromatography, sucrose gradient sedimentation, and hydroxyapatite chromatography, the partitioning of H2A.Z within dissociated octamers, mononucleosomes, and chromatin fibres were respectively assessed. Within all three structures, H2A.Z associated with stabilized forms. However, the salt-dependent thermal analysis of H2A.Z-H2B dimers by circular dichroism showed that the variant dimer was largely unstructured. The deposition of H2A.Z also occurred independently of linker histones. MeCP2 is a chromatin binding protein best known for its ability to repress transcription. While its roles in neuron development have been well-studied, little is known of its interactions within native chromatin. Shortly after MeCP2 was discovered, it was postulated that MeCP2 would behave as a global repressor. However, recent findings have contested this idea. If MeCP2 does act as a universal silencer, it was hypothesized that changes to global chromatin modifications would affect the distribution of MeCP2 within chromatin. HeLa S3 cultures were chemically treated with 3-aminobenzamide or butyrate to induce either DNA hypermethylation or histone hyperacetylation. Neither treated culture resulted in a redistribution of MeCP2 within chromatin. Moreover, the majority of MeCP2 was present within nuclease-accessible, active chromatin. Interestingly, the butyrate treatment resulted in proportional losses of MeCP2 within fractionated chromatin that were not due to changes in MeCP2 transcription. MeCP2 was also observed to bind to mononucleosomes containing DNA that was >146 bp - ~160 bp. These results suggested that MeCP2 does not act as an indiscriminate silencer, but more likely as a specific transcriptional regulator. Most studies of MeCP2 interactions with chromatin were performed using reconstituted chromatin templates in vitro. However, it is not known if MeCP2 interacts with chromatin in a tissue-specific manner. In addition, as MeCP2 has a broad distribution throughout all chromatin types, it is not known if histone variants or PTMs influence MeCP2 deposition. Therefore, the tissue specificity of MeCP2 binding and the influence of nucleosomal components were investigated. MeCP2 has a differential distribution throughout chromatin extracted from rat brain, liver, and testis. The brain has significantly more MeCP2 than the liver or testis and this was reflected in the MECP2 mRNA amounts. Using native co-immunoprecipitations, MeCP2 was shown to interact with mononucleosomes containing specific histone variants and PTMs: H2AX, H3K27me3, and H3K9me2. These novel interactions may further specialize the MeCP2-bound chromatin regions. Finally, two novel hypotheses regarding the regulation of MeCP2 are proposed. In the first, the regulation of MeCP2 turnover is proposed to occur through the poly-ubiquitination of the two MeCP2 PEST domains, followed by proteolytic degradation. The second hypothesis proposes that the use of histone deacetylase inhibitors could be used to control the levels of MeCP2 expression, in conjunction with gene therapies, for the treatment of Rett syndrome.

Proanthocyanidins (PAs) are polymeric phenolic chemicals produced by many plant species that may contribute to protection of tissues against biotic and abiotic stress conditions. In poplar (Populus spp.) leaves, PA biosynthesis is rapidly activated by insect herbivore damage, indicating that PAs may be an inducible chemical defence. In this study, the expression of PA biosynthetic genes was monitored in poplar leaves exposed to several stress stimuli. The PA pathway was shown to be rapidly activated at the level of gene transcription by stresses such as elevated light, UV-B irradiation and infection of leaves by a biotrophic fungal parasite. A transcription factor gene of the R2R3 MYB type, MYB134, was found to be co-activated with PA biosynthetic genes under these stress conditions. When overexpressed in transgenic poplar, this gene induced a strong, specific activation of the PA pathway, indicating that it might function as a regulator of stress-induced PA metabolism in poplar. MYB134 was shown to bind to promoter fragments of PA biosynthetic genes which contained a conserved DNA cis-element found in the promoter regions of many other phenylpropanoid genes including putative MYB134-regulated genes. A global transcriptome analysis of leaves of the MYB134-overexpressing poplar plants confirmed that the PA pathway activation was complete and specific, and led to the identification of a number of putative novel PA biosynthetic and regulatory genes. These results indicate that stress-responsive PA and flavonoid metabolism in poplar may be regulated by a complex system involving both positive and negative regulation. Preliminary results are also presented related to analysis of PA functions in transgenic plants, and the use of MYB134 to engineer PA metabolism in plants other than poplar. This study provides insight into the regulatory mechanisms controlling stress-induced PA metabolism, and expands our understanding of roles that this biological response may play in poplar.

A good understanding of the various mass and heat transport, and electrochemical re-action processes is required for design strategies that lead to increased performance of proton exchange membrane (PEM) fuel cells. Traditionally, attempts at understand¬ing how these processes interact has been through mathematical modeling where efforts have focussed on understanding the cathode. The interaction between mass transport, membrane hydration and the effects of heat generation and transfer com¬plicates our understanding of relevant processes, hampering the effort to improve fuel cell performance. To further our basic understanding of how the power density of a PEM fuel cell can be increased, and, thereby, decrease the cost of a complete fuel cell system, a comprehensive performance model of a PEM fuel cell has been formulated and investigated. This model explicitly examines the anode as well as the cathode, and includes the effects of energy transfer as temperature control is critical to PEM cells. The results of this model suggest that humidification of the cathode gas stream may be reduced at high operating currents, the temperature peak across a single cell increases as operating temperature decreases, and the gas backing has a significant effect on mass transport at typical operating potentials, especially with air operation.

Original poems in English and Spanish.

This thesis critiques the dominant theorization of Canadian sanctuary as expressed by Randy Lippert. Particularly, I contend that Lippert’s Foucaudian analysis offers an impoverished understanding of sanctuary recipients by insisting they are political only insofar as they embrace bare life and become a silent spectacle. To re-conceptualize the political role of recipients, I evoke Hannah Arendt and Jacques Rancière’s notion that politics is constitutive of an interruption. I suggest that, living in a borderland between citizenship/non-citizenship, sanctuary recipients draw critical attention to their own exclusions and thus enact the political interruption par excellence. However, Arendt and Rancière’s stipulation that this interruption must be visible also limits political efficacy for recipients for it necessitates that they must expose themselves as helpless spectacles. I argue that this uncontested commitment to visibility is also dominantly expressed by theorists, such as Jenny Edkins, who are concerned with agency for other abject subjectivities. Troubling, this dedication to visibility results in the same apolitical formulation of sanctuary recipients that Lippert offers. As an alternative, I conclude that a type of (in)visible interruption offers a more a fruitful way to understand political agency for sanctuary recipients, and indeed for other seemingly abject figures.

An original full-length theatrical play in three parts, Hand of Jane deals with themes of faith, family and responsibility to the past, and examines human spiritual evolution through the story of a father and daughter, and Jane, a mystical guide loosely based on Jane Goodall.

In this thesis study, three different feature selection methods, LASSO, SLR, and SMLR, were tested and compared using microarray fold change data. Two real datasets were used to first investigate and compare the ability of the algorithms in selecting feature genes on data under two conditions. It was found that SMLR was quite sensitive to its parameter, and was more accurate in selecting differentially expressed genes when compared to SLR and LASSO. In addition, the model coefficients generated by SMLR had a close relationship with the magnitude of fold changes. Also, SMLR's ability in selecting differentially expressed genes with data that had more than two conditions was shown to be successful. The results from simulation experiments agreed with the results from the real dataset experiments. Additionally, it was found that different proportions of differentially expressed genes in the data did not affect the performance of LASSO and SLR, but the number of genes selected by SMLR increased with the proportion of regulated genes. Also, as the number of replicates used to build the model increased, the number of genes selected by SMLR increased. This applied to both correctly and incorrectly selected genes. Furthermore, it was found that SMLR performed the best in identifying future treatment samples.

A permutation array, represented by PA(n, d), is a subset of Sn such that any two distinct elements have a distance of at least d where d is the number of differing positions. We analyze the upper and lower bounds of permutation codes with distance equal to 4. An optimization problem on Young diagrams is used to improve the upper bound for almost all n while the lower bound is improved for small values of n by means of recursive construction methods.

The process of creating and using participatory photonovels can empower immigrant ESL speaking women and also act as a tool to educate these women about a specific health topic. This was a qualitative case study that was conducted at an immigrant society in an urban center in British Columbia. The ESL speaking immigrant women in this study created a photonovel called From Junk Food to Healthy Eating: Tanya’s Journey to a Better Life. The findings of this research reveal some of the health experiences of ESL speaking immigrant women in Canada. The results also contribute to the growing body of knowledge that discusses effective or ineffective means to educate ESL speakers about health by improving their health literacy. Most notably, however, the photonovel project engaged the women in an educational process that raised their critical consciousness.

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’.