Twenty two Bacillus spp. isolates from the Phaseolus vulgaris rhizosphere were identified using Biolog™, GC-FAME and 23S rDNA analysis. Some Bacillus isolates produced copious amounts of indoleacetic acid in vitro, in culture medium supplemented with L-tryptophan. Spontaneous cc-methyl tryptophan resistant mutants of Bacillus megaterium S49 exhibited altered IAA production and excreted tryptophan into the culture medium. Coinoculation of Rhizobium etli TAL 182 with some Bacillus spp. under gnotobiotic conditions promoted nodulation of P. vulgaris. In contrast, decreased nodulation was observed in response to low and high lAA-producing Bacillus mutants, suggesting that the nodulation response in bean was not dependent on the in vitro level of IAA production by the Bacillus coinoculant. Coinoculation of Bacillus spp. and Rhizobium spp. resulted in a unique and significant synergistic enhancement of lateral root formation and root hair initiation which was independent of plant host. These observations provided direct evidence for a beneficial interaction on root morphology which may account for enhanced nodulation by creating additional infection sites for the Rhizobium. The presence of live Rhizobium and Bacillus was necessary for the root hair proliferation response. Coinoculation of Rhizobium TAL 182 with cell extracts of Bacillus S49 failed to induce root hair proliferation or enhance nodulation of P. vulgaris. A biologically active Rhizobium TAL 182 was essential for the observed response, indicating that root hair proliferation and enhanced nodulation were direct consequences of the bacterial species interaction. Nodulation and symbiotic specificity of Rhizobium TAL 182 were altered by the presence of Bacillus S49. Split-root experiments showed that coinoculation suppressed host-controlled regulation of nodulation. Bacillus S49 facilitated heterologous nodulation of Rhizobium TAL 182 on P. acutifolius, indicating that a host plant response was also involved in the bacterial interaction. Exogenous aminoethoxy vinyl glycine, a negative regulator of ethylene biosynthesis, inhibited root hair formation in P. vulgaris. These inhibitory effects were reversed by the presence of both Bacillus S49 and Rhizobium TAL 182. The interaction between bacterial species on root hair induction and nodulation patterns in P. vulgaris is discussed. / Land and Food Systems, Faculty of / Graduate

Information about the medicinal uses of forty-two plant species was collected from traditional healers and knowledgeable villagers from a variety of different ethnic groups in Nepal. Illnesses for which these plants are used are those perceived in western style medicine to be caused by bacterial, fungal or viral pathogens. Methanol extracts of the species were screened for activity against a variety of bacteria, fungi and viruses, under various light conditions to test for photosensitizers. Thirty-seven extracts showed activity against bacteria and thirty-five showed activity against fungi. Only eight were active against Gram-negative bacteria. The exposure to UV-A light had a considerable effect on the activities of some extracts, with eight extracts being active only when exposed to light. The antibacterial and antifungal effects of fifteen extracts were enhanced upon exposure to light. Fifteen extracts showed 100% inactivation of at least one virus, and fifteen showed partial activity. Eight extracts were active only when exposed to light, and the antiviral effect of eight extracts was enhanced upon exposure to light. A species showing antibacterial activity, Centipeda minima (Asteraceae), and one showing antiviral activity, Carissa carandas (Apocynaceae) were the focus of bioactivity guided fractionation. Centipeda minima was found to contain three sesquiterpene lactones, identified as 6-O-methylacrylylplenolin, 6-O-isobutyroylplenolin, and 6-O-angeloylplenolin. 6-O-Methylacrylylplenolin had not been previously isolated from C. minima. All three of these sesquiterpene lactones had activity against Bacillus subtilis and Staphylococcus aureus. A fraction from the methanol extract of Carissa carandas was quite active against herpes simplex virus. This fraction was found to contain a derivative of 3,4,5-trimethoxycinnamic acid. / Science, Faculty of / Botany, Department of / Graduate

This thesis develops some statistical models for the multivariate analysis of longitudinal data on the basis of the dispersion models of J0rgensen (1987a, 1996), consisting of three topics: multivariate dispersion models and their application to regression analysis, stationary time series models with non-normal margins and state space models with Markov latent processes. The goal of the thesis is to develop statistical models which can accommodate features of both trend and dependence for longitudinal data. This thesis focusses mainly on the following three types of longitudinal data, namely (1) many short time series, (2) a few long stationary time series and (3) a few long non-stationary time series with time-varying covariates. A class of multivariate dispersion models is proposed to deal with data of type (1), in a spirit similar to multivariate analysis based on the multivariate normal distribution. Under these multivariate parametric models, population-averaged models (Diggle et al., 1994) are revisited, where approximate inferences for regression parameters are presented, including the generalized estimating equation (GEE) of Liang and Zeger (1986) as a special case. The thesis also presents a class of stationary autoregressive moving-average (ARMA) models with exponential dispersion model margins for data of type (2). The class of ARMA models is defined as a special case of a class of stationary infinite order moving average processes constructed by means of the thinning operation of Joe (1996a). For analysis of type (3) data, two classes of state space models, including one with stationary latent processes and another with non-stationary latent processes, are proposed. To estimate regression parameters in both classes of models, we develop an algorithm for solving the so-called Kalman estimating equation (KEE), corresponding to a modified EM-algorithm where the E-step is approximated by the Kalman smoother that estimates the latent process via the best linear unbiased predictor (BLUP). Two simulation studies are conducted in the thesis based on Poisson-gamma models. One is for the comparison of the efficiency of the K E E approach and the Monte Carlo E M (MCEM) algorithm. The other simulation study is for the examination of the utility of the model diagnosis for detecting the misspecification of stationarity and non-stationarity for latent process. The thesis contains two data analyses. One data set consists of daily counts of emergency room visits for respiratory diseases to the hospital of Prince George, British Columbia, along with covariates of air pollution variables and meteorological variables. These data are analyzed through state space models to investigate the relationship between air pollution and respiratory morbidity. The other data set, consisting of the monthly number of poliomyelitis cases in the USA from 1970 to 1983, is analyzed based on the Poisson stationary-gamma model to study whether or not there is an evidence of a decreasing trend in the rate of polio infections in the USA. / Science, Faculty of / Statistics, Department of / Graduate

The most surprising outcome from the Victoria School of Art and Design's first half century is that it survived into its second. How it survived, and how it almost failed to, is the subject of this thesis. The main argument is that community support for the VSAD, or lack of it, was based more on pragmatic concerns, rather than on whether people liked the art being produced. Among those concerns, the most talked about was art training for employable skills. Led by Anna Leonowens, who later became the subject of the musical The King and I, well-to-do citizens in Halifax, Nova Scotia founded the VSAD in 1887. In 1925 the school changed its name to the Nova Scotia College of Art. Its current name, the Nova Scotia College of Art and Design, came in 1969, the year that the College became what was then the only autonomous degree granting art institution in Canada. As part of an international movement, the VSAD shared its late nineteenth century origins with similar art schools throughout North America, Europe, Britain and its colonies. Many of these schools also shared common purposes: to sharpen the graphic skills of industrial designers, to provide instruction in the fine and decorative arts, and to train drawing teachers for public and private schools. Of the different groups supporting the Halifax school, women and their organizations were the most consistent and consequential, especially Halifax's Local Council of Women. A properly funded art school, they argued, could generate jobs, stimulate economic gains, and foster higher standards of civic culture within the community. This study looks at the VSAD's supporters, teachers, and administrators during its first half century. It describes how the school, with its inadequate enrolment, budget, and space, played a limited role in generating art-related employment before the Great War. It is only with the principalship of Elizabeth Styring Nutt from 1919 to 1943, with her strong community connections and decades-long commitment to training artist-workers, that the school finally gained relative security and success. / Education, Faculty of / Graduate

We examine a construction of topological spaces over an arbitrary polyhedron and show that it subsumes the lattice construction of R. R. Douglas and A. R. Rutherford. A Simplicial Approximation Theorem is proven for the general construction, for maps from a polyhedron to one of our spaces lying over another polyhedron. A special case of our construction (a slight generalization of the lattice construction) is examined and a class of locally trivial bundles is constructed. These are used to examine neighbourhood structure in the special case. We also enumerate exactly which spheres can be constructed by a lattice construction on a product of real orthogonal, complex unitary or quaternionic symplectic groups. The fundamental group of the real complete flag manifolds is determined following a detailed exposition of Clifford algebras. Appendices are provided on the diagonalization of quaternionic Hermitean matrices and on a generalized mapping cylinder that can be regarded as an endofunctor on the category of locally trivial bundles over a fixed locally compact base. / Science, Faculty of / Mathematics, Department of / Graduate

Dysfunction in the cortical regulation of subcortical dopamine (DA) neurotransmission has been proposed to contribute to the pathophysiology of schizophrenia. However, before such a hypothesis can be fully described, it is necessary to establish the normal functional interactions of these systems. To this end, in vivo microdialysis was used to measure extracellular subcortical DA concentrations during electrical stimulation of the prefrontal cortex (PFC) and during feeding in rats. Because excitatory amino acids such as glutamate (Glu) are thought to be the predominant neurotransmitters used by cortical projection neurons, assessing the contributions of Glu receptors to DA release evoked by cortical stimulation and feeding has been the primary focus of these experiments. Bilateral electrical stimulation of the PFC produced a rapid, current-dependent increase in DA release in the striatum and nucleus accumbens (NAc). This response was not affected by local application of the ionotropic Glu receptor antagonist kynurenic acid (KYN). In contrast, local application of the metabotropic Glu receptor agonist ACPD blocked the effects of cortical stimulation. Application of the ionotropic Glu receptor antagonists, AP5 and CNQX, in the ventral tegmental area (VTA) blocked the effect of stimulation on accumbal DA release. Thus, the PFC modulates subcortical DA release and this effect relies on Glu receptors in the VTA but not the NAc. Given that electrical stimulation is an artificial stimulus, it was deemed worthwhile to investigate the role of glutamatergic mechanisms in regulating DA release occurring under natural conditions, i.e. during feeding. Thus, in rats deprived of food for 18 hours, feeding resulted in substantial increases in DA release in the NAc. This effect was potentiated by local application of KYN and was blocked by local ACPD application. The effect of feeding was also markedly attenuated by application of ionotropic Glu receptor antagonists in the VTA. Thus, the neurochemical mechanisms regulating feeding-evoked DA release are consistent with those regulating cortical stimulation-evoked DA release. These results demonstrate that Glu receptor mechanisms in the VTA mediate increases in DA transmission in the NAc evoked by a variety of stimuli. Secondary to this effect, local Glu receptors inhibit basal and evoked DA release in the NAc. / Medicine, Faculty of / Graduate

This study is a qualitative investigation of a person-centered support option called micro boards. A micro board is a small non profit society comprised of family and friends who assist persons with disabilities to develop individualized housing and support options. Defining features of the micro board project include direct funding to individuals with disabilities to secure housing and support options, freedom to choose where and with whom to live, and autonomy in hiring and defining the nature of personal care and support. Three persons with severe disabilities were the primary focus of this study. These individuals required extensive supports in all aspects of daily living including feeding, dressing, and mobility. They resided in three separate subsidized or cooperative living arrangements in a large urban centre in the Province of British Columbia. Two organizations central to the micro board project were also a focus of study. The study period was eighteen months. Qualitative techniques were employed to collect and analyze data regarding lifestyle quality in the micro board project, and organizational assumptions and characteristics inherent in this support paradigm. Results indicated that all three participants with disabilities experienced positive lifestyle gains as a result of the micro board project. Direct funding and the freedom to choose accommodation and individualized support structures were identified as axial to lifestyle quality. Participants also experienced increased community participation and expanding networks of social support as a result of the micro board project. An analysis of the characteristics and themes embedded in the multiple case studies identified five responsive organizational characteristics which contributed to the development of the micro board project, and assisted in the achievement of a quality life in the community for the three participants in this study: willingness to change; inclusion of persons with disabilities and their families in organizational policy; small, flexible support structures; collaborative planning; and a holistic view of support grounded in social justice. These results are discussed in relation to previous research done in this area. Inferences are made about how factors such as lifestyle planning, empowerment, personal perceptions of disability, and responsive support systems influenced lifestyle quality. Parallels are drawn to related health care fields, and a restructuring of disability support is explored. Limitations of the research are identified, and potential areas for further research are suggested. / Education, Faculty of / Educational and Counselling Psychology, and Special Education (ECPS), Department of / Graduate

An important aspect of causal inference is assessing the contingency between antecedents and outcomes. Research on how people integrate contingency information has focused on identifying the "best" rule to descriptively model the information integration process. In contrast to this ruleanalytic approach, the present feature-analytic approach asks the question, "What features are important in describing the information integration process?" Five key propositions of the present account are that (a) people prefer strategies that involve contrasting data with conflicting implications to strategies that involve seeking only confirmatory or marginal-frequency data, (b) people weigh positive information more heavily than negative information, (c) people are biased toward testing sufficiency rather than necessity, (d) people are biased toward strategies that cohere with the perceived direction of time (input tests) rather than those that violate this perception (outcome tests), and (e) people are biased toward probability strategies that enable comparability across data contexts rather than frequency strategies that do not. In three experiments, subjects received contingency information on two, temporally sequenced, binary variables in numeric summary format. Subjects were asked to rate the direction and magnitude of the causal relation between the two variables based on the contingency information provided. Results of Experiments 1-3, corroborated by a reanalysis of data from two published experiments employing a discrete-trial method for presenting stimuli, strongly supported the first four propositions. To test the fifth proposition, I reanalyzed data from five published experiments in addition to an analysis of data from Experiment 3. Results indicated that within each data context preferences for either frequency, conditional-probability, or joint-probability strategies emerged, but across contexts consistent preferences for one type of combination method was lacking. Taken together, the findings indicate that invariant properties of the information integration process in causal inference can be isolated but these consist of systematic feature preferences rather than stable rankings of rules in terms of their predictive utility. / Arts, Faculty of / Psychology, Department of / Graduate

Agricultural activities in the Pampanga river Basin (PRB) are threatened by the increasing population and development thrusts of the Philippine government. This study was conducted to develop a framework by which problems, initiatives, and interactions among land-use changes, water quality and governance issues may be assessed employing Geographic Information Systems (GIS) techniques. Stream stations were sampled for nitrate, phosphate, temperature, dissolved oxygen, total dissolved solids, chemical oxygen demand and pH. Land-use changes were analyzed through GIS, while land-use planning was investigated through workshop participation and review of government plans. Agricultural land increased 0.6% annually from 1953 to 1980 due to conversion of grasslands, wetlands and forests to agriculture, and declined 0.5 % annually from 1980 to 1993 due to expansion of settlements. A provincial land-use plan would accelerate conversion rather than protect agricultural lands. Water quality in the Pampanga river and its tributaries is deteriorating in both the spatial and temporal dimensions. The eruption of Mt. Pinatubo was responsible for increased levels of ortho-phosphate, TDS, and temperature in streams, but the low DO during the start of the rainy season and the high nitrate-N concentrations are indicators of human influence on water quality. Streams with catchments having the same predominant land-use classification exhibited similar trends in water quality. Animal species in different area classifications also affected water quality at different flow periods. Buffer analysis on 500 metre zone along the streams gave best values. The effect of runoff is altered by the type of land-use, specifically the presence of rice fields. The management of nitrate-N based on a nitrogen budget revealed that animal manure and inorganic fertilizer are major sources of nitrogen in the basin. The hotspot areas are catchments with large settlement areas, and/or with a very high animal population. Alternative scenarios revealed no significant changes in water quality even with a three-fold increase in animal production or 10 % agricultural land conversion. A cautious optimism is anticipated in involving the barangay captains in the overall management of the environment, in particular, the control of stream pollution that endangers the fishing industry. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

"Nineteenth-Century Archaeology and the Retrieval of the Past: Carlyle, Scott, Bulwer-Lytton, Pater, and Haggard" shows that the recovery, analysis, and interpretation of material history was a model for investigating, re-creating, and reinventing the past in Thomas Carlyle's "Past and Present" (1843), Walter Scott's "The Antiquary" (1816), Edward Bulwer-Lytton's "The Last Days of Pompeii" (1834), Walter Pater's "The Renaissance" (1873) and "Greek Studies" (1895), and H. Rider Haggard's "She". (1887). Through the self-conscious use of archaeological language and methodology, the authors of these fictional and nonfiction texts composed what I term "narratives of continuity," in which the retrieval of artifacts is a tangible means of drawing connections between past and present. These narratives illustrate teleological interpretations of history espoused by archaeologists, who themselves sought prefigurements of modern culture as they studied archaeological records. This thesis in part examines philosophic, scientific, and political thought underlying the penchant in these texts to link past and present as a means of sustaining historical identity and thereby validating present institutions. To the Victorians, archaeology was an authenticating medium for the material consolidation of tradition. The archaeological themes and language in these texts have a counterpart in their form. Devices such as editorial "framing" and narrative "stratification" contribute to the sense of text as archaeological site. These texts are "sites" for the recovery and substantiation of the past. They also chart developments in archaeology over the course of the nineteenth century. The archaeological trope evolves with archaeology's maturation from amateur antiquarianism (reflected in Scott's 1816 novel The Antiquary) to the first glimpses of professional and scientific archaeology at the end of the century depicted in Haggard's "She" (1887). Narratives of continuity, moreover, emanate from several fields of Victorian archaeology. The writings of Carlyle, Scott, Bulwer-Lytton, Pater, and Haggard depict a range of archaeological activity spanning domestic excavation to foreign archaeology in the Middle East, Egypt, Greece, Italy, and South Africa. / Arts, Faculty of / English, Department of / Graduate