This study describes the integration of harmonic idiom and tonal design in Schoenberg's First Quartet, op. 7. Two general questions are answered: whether the composition should be judged by common-practice-period norms, and whether a coherent tonal structure is truly discernible. Chapter 1 first surveys the existing literature. It then describes a prime motivator of foreground chromaticism in the quartet—the chromatic surrounding of tonic and dominant pitches—and discusses two features of large-scale pitch organization applicable to Schoenberg's first-period music that contravene common-practice-period norms: tonal structure consisting of a pattern of keys, and systematic use of dual or even multiple tonics in place of monotonality. Examples illustrate three types of graphic representation of tonal duality to be used in the study. The next four chapters describe tonal process within and across the four "movements" of the quartet (Schoenberg's Parts I through IV). Chapter 2, which studies Part I, reveals systematic avoidance of V-I function in the opening key, D, tonal rivalries between D and each of its two semitone-related keys, and the beginning of a large-scale chromatic surrounding of the key of D. Chapter 3, on Part II of the quartet, demonstrates continuation of the rivalry between tonics D and Dt> by their use as competing secondary tonics within the Scherzo, and the harmonic progression VII-I replacing V-I at a crucial structural point. Chapter 4, on Part III of the quartet, describes tonal duality as it occurs in the Adagio, the furthering of the tonal plot in a section that engages in a "plagal" system of tonality, and the beginning of a large chromatic surrounding of A. Chapter 5 shows that Part IV eschews a simple relationship between the A-major tonic of the Rondo and the D-major tonic of the Coda by allowing the infiltration of elements of the Db-major collection. Chapter 6 summarizes the evidence contradicting a monotonal understanding of the composition and reviews evidence that the demonstrated multi-tonal coherence is part of the musical reality of the work. / Arts, Faculty of / Music, School of / Graduate

Many researchers have failed to find a relationship between experience and judgment accuracy. In this study the purpose was to understand the relationship between experience and expertise in clinical judgment. Common sense suggests that experienced subjects make better quality judgments, compared to novices. Clinical judgments, however, are ill-structured and characterized by uncertainty; they take place in a dynamic context, with delayed or nonexistent feedback and are difficult to learn. Cognitive operations that translate "cues" (such as risk factors, signs, and symptoms) into judgments are not fully understood. Cognitive constructs (conceptual structure, sensitivity to patterns in data, and judgment process) and individual differences in age, education, and experience were explored to identify their relationship to judgment expertise. Indicators of judgment quality were: accuracy, consistency, latency, confidence, calibration, and knowledge accessibility. In phase 1 of this study, cues were identified that best predicted healing time for 258 surgical patients with abdominal incisions. In Phase 2, the subjects were 36 nurses with a range of experience caring for surgical patients. Generating both quantitative and qualitative data, subjects made judgments about incisional healing on the basis of information from actual patients. Multidimensional scaling was used to reveal conceptual structure, and lens modeling was applied to assess sensitivity to broad patterns. An information board task with think-aloud protocols demonstrated judgment process. The selection of tasks was based on their analysis- or intuition-inducing features, using K. R. Hammond's (1990) cognitive continuum theory. Experience accounted for a only a small proportion of variance in performance, whereas confidence in judgment was more strongly related to experience. Taken together, these findings replicated previous research. Protocol data showed that metacognition, knowledge accessibility, and reflectivity increased with experience. Conceptual structure predicted judgment accuracy under intuitive conditions. Support was found for Dreyfus and Dreyfus' (1986) hypothesized transition in cognition, from deliberate processing of discrete cues, to intuitive processing of patterns of cues encoded in memories for specific cases. This study has theoretical significance by adding to knowledge about clinical judgment, and by increasing understanding of cognitive changes associated with expertise. This study has practical significance in providing direction for the development of teaching methods aimed to increase learning from experience in probabilistic contexts. / Education, Faculty of / Educational and Counselling Psychology, and Special Education (ECPS), Department of / Graduate

The objective of the first half of this thesis was to develop an efficient and sensitive method to detect lignin in intact tissues using confocal laser scanning microscopy and to characterize the timing and quality of lignin deposited during Arabidopsis thaliana development. Lignin could first be detected 48h post-imbibition. During subsequent development, lignification of vasculature proceeded in a temporally coordinated manner, with lignin deposition closely following secondary wall thickening in vascular elements, in a cell-by-cell sequence. A spatially and temporally distinct pattern of syringyl lignin deposition was observed along the developing stem. Syringyl type lignin appeared only once fiber differentiation was initiated at day 21. The second half of the thesis is dedicated to identification, purification and characterization of a coniferin specific P-glucosidase from Pinus contorta xylem, and cloning of the corresponding cDNA. Coniferin accumulates to high levels during cambial reactivation, and a cinnamyl alcohol glucoside/ p-glucosidase system is thought to play a key role in lignification in gymnosperm tissues. However, evidence for the existence of P-glucosidases specific for cinnamyl alcohol glucosides in lignifying xylem has not been conclusive. Using a range of synthetic aromatic P-glucosides and coniferin as substrates, two major P-glucosidases present in total extractable xylem protein were identified. The enzyme that demonstrated a high specificity/ activity for coniferin was purified to homogeneity using anion exchange, hydrophobic interaction and gel filtration chromatography. Based on the N-terminal amino acid sequence of this protein, the corresponding cDNA was isolated from a library constructed from differentiating pine xylem. A 1909 bp full length cDNA sequence was confirmed to be that of coniferin Pglucosidase on the basis of it's homology to other plant P-glucosidases and by the demonstration of coniferin hydrolytic activity and similar substrate specificity when expressed in E. coli The deduced 513 amino acid protein contains a 23 amino acid N - terminal signal peptide that is characteristic of eukaryotic secretory proteins. The isolation of the coniferin |3-glucosidase cDNA offers novel opportunities to clarify the ultimate steps of lignin biosynthesis. It also opens a route to the possible modification of lignin in trees by down-regulation of its activity through genetic engineering. / Science, Faculty of / Botany, Department of / Graduate

Symmetries of a system of differential equations are transformations which leave invariant the family of solutions of the system. Infinitesimal Lie symmetries of locally solvable analytic differential equations can be found by using Lie's algorithm. We extend Lie's algorithm to one which can calculate infinitesimal Lie symmetries of analytic systems of differential equations which are not locally solvable. Local infinitesimal symmetries of differential equations are flows of vector fields which depend on local properties of solutions and have been extensively calculated and applied. In contrast infinitesimal nonlocal symmetries, which are flows of vector fields depending on nonlocal properties of solutions, have only recently been introduced. Using our extension of Lie's symmetry algorithm, we study the infinitesimal nonlocal symmetries of potential type introduced by Bluman, Kumei and Reid. We give verifiable criteria for useful potential systems and give a complete potential symmetries analysis for a class of nonlinear diffusion equations. We also find large classes of higher order scalar and systems of partial differential equations admitting potential symmetries. / Science, Faculty of / Mathematics, Department of / Graduate

This study chronicles the course of an important but little known Canadian war: the war between people and weeds in Western Canada. Arising from intense competition between two groups of immigrants, this conflict started in Europe, spread to Eastern North America and reached a climax on the broad expanses of the Canadian Prairies. By the early 1940s weeds had gained the upper hand on their human competitors and many predicted the end to extensive grain production in the West. This did not occur, however, because of the timely development of 2,4-D and other selective herbicides immediately following the close of World War II. These potent chemical weapons gave prairie farmers new hope at a time when defeat seemed all but certain and they are largely responsible for the expensive standoff between farmers and weeds that persists to this day. Recounting the history of weeds and weed control in Western Canada between 1800 and 1950 serves a number of functions. One is to provide weed scientists with some historical background and an object lesson in the consequences of seeking simple solutions to complex, long-standing problems. Another is to remind historians that we cannot truly understand the history of western settlement and agriculture without understanding the practical issues that dominated the daily lives of past generations of farmers. Yet a third function is to introduce a specific environmental history approach to Canadian historians while, at the same time, encouraging them to pay more attention to recent developments in this American-dominated field. A fourth and final reason for investigating the historical relationship between people and weeds is that it can be used to symbolize something far larger: the relationship between culture and nature in general. An exploration of this issue is made possible by the curious relationship between people and weeds, a relationship summed up by the thesis that weeds are both the the products of and participants in culture. The dissertation concludes with a discussion of recent trends in weed science and, in particular, of the merits of the "new" doctrine of weed management. Canadian historians are lectured on the danger of ignoring nature when writing about history and readers are asked to consider what the terms "nature" and "culture" mean. Do they represent discrete subjects, separate spheres of existence, a dichotomy? Or, are they just different aspects of a larger, more complex whole? / Arts, Faculty of / History, Department of / Graduate

Glacial-interglacial variability in upwelling on the NW Mexican margin is assessed by reconstructing the history of organic carbon and biogenic opal deposition and measuring the Ba/Al ratio in three piston cores that span the upper to the lower continental slope. Rates of accumulation of organic carbon, opal and to some degree biogenic barite are higher in interglacial intervals, indicating that upwelling-induced productivity was higher during the warm periods over the last 140,000 years. Despite cyclic changes in organic carbon accumulation, matrix-corrected HI values in the mid- and lower- slope cores are invariant and are similar to values in the laminated intervals from the oxygen-minimum site. This suggests that changes in organic carbon content are controlled by productivity variations and are not due to differential preservation induced by variations in bottom water oxygen concentrations. The lowest HI values in Mexican Margin sediments occur concurrently with large increases in grain size. Thus, increased degradation resulting from winnowing is offered as the leading explanation for the hydrocarbon impoverishments in the bioturbated upper slope deposits. Late Quaternary records of denitrification in the oxygen-deficient subsurface water masses of the Eastern Tropical North Pacific (ETNP) are constructed using ¹⁵N/¹⁴N ratios measured on bulk sediments. The profiles show a synchronous decrease in denitrification during the glacial periods over the last 140 kyrs. It is suggested that, because nitrate is a limiting nutrient in the modern ocean, a consequent increase in the oceanic nitrate inventory could have contributed to the observed decrease in glacial atmospheric pCO₂ by enhancing the fertility of the ocean. The glacial decreases in denitrification in the ETNP are attributed to large reductions in upwelling-induced fluxes of organic detritus on the margin in response to glacial shifts in the wind field off NW Mexico associated with the growth of Laurentide ice on northern North America, the establishment of a resident high pressure cell over the ice sheet, and the bifurcation of the Jet Stream. / Science, Faculty of / Graduate

Computational problems on graphs often arise in two- or three-dimensional geometric contexts. Such problems include assigning channels to radio transmitters (graph colouring), physically routing traces on a printed circuit board (graph drawing), and modelling molecules. It is reasonable to expect that natural graph problems have more efficient solutions when restricted to such geometric graphs. Unfortunately, many familiar NPcomplete problems remain NP-complete on geometric graphs. Indifference graphs arise in a one-dimensional geometric context; they are the intersection graphs of unit intervals on the line. Many NP-complete problems on arbitrary graphs do have efficient solutions on indifference graphs. Yet these same problems remain NP-complete for the intersection graphs of unit disks in the plane (unit disk graphs), a natural two-dimensional generalization of indifference graphs. What accounts for this situation, and how can algorithms be designed to deal with it? To study these issues, this thesis identifies a range of subclasses of unit disk graphs in which the second spatial dimension is gradually, introduced. More specifically, τ-strip graphs "interpolate" between unit disk graphs and indifference graphs; they are the intersection graphs of unit-diameter disks whose centres are constrained to lie in a strip of thickness τ. This thesis studies algorithmic and structural aspects of varying the value τ for τ-strip graphs. The thesis takes significant steps towards characterizing, recognizing, and laying out strip graphs. We will also see how to develop algorithms for several problems on strip graphs, and how to exploit their geometric representation. In particular, we will see that problems become especially tractable when the strips are "thin" (τ is small) or "discrete" (the number of possible y-coordinates for the disks is small). Note again that indifference graphs are the thinnest (τ = 0) and most discrete (one y-coordinate) of the nontrivial τ-strip graphs. The immediate results of this research concern algorithms for a specific class of graphs. The real contribution of this research is the elucidation of when and where geometry can be exploited in the development of efficient graph theoretic algorithms. / Science, Faculty of / Computer Science, Department of / Graduate

Asymptotic giant-branch (AGB) stars are identified and classified in five 7'x7' fields spaced along M31's SW semi-major axis using a four band photometric system. An investigation of the AGB luminosity functions and red giant-branch widths reveals significant differences between the star forming histories of the five fields. The distance modulus of M31 is derived using carbon stars (C-stars) and found to be consistent with both a value obtained from Cepheids and with values in the literature. The ratio of AGB C- to M-stars (C/M ratio) in the five fields is found to increase with galactocentric distance and it is shown that photometric incompleteness is not responsible for this effect. This is the first clear demonstration of a varying C/M ratio in an external galaxy. The C/M ratios appear to be insensitive to star-forming history differences but sensitive to metallicity differences between the fields. Previous observations are used to define a relationship between the C/M ratio and metallicity, and this is used to obtain estimates of the field metallicities. These estimates are found to be consistent with a previous measurement of M31's metallicity gradient. The C /M ratios measured in M31 indicate that the composition of M31's interstellar medium may be position dependent, and evidence is cited in favour of this. Follow up spectroscopy was obtained in two of the five fields, and is used to show that the photometric system did an excellent job of discriminating between M-, S- and C-stars. Of the 48 C-stars for which spectra were obtained, 7 have strongly enhanced ¹³C bands (J-stars), 2 have strong H⍺ emission, while 3 are found to exhibit enhanced Li absorption (Li-stars). Both the J- and Li-stars are fainter than predicted by current theoretical models, while the colours of the H⍺ stars suggest they may be in the terminal phases of their evolution. The C₂ and CN bandstrengths of the C-stars are measured, and no correlation between these bandstrengths and either M[sub bol] or (V — I) is found. It is suggested that this lack of correlation is due to an age spread. The spectra of the first confirmed S-star in M31 is presented, and two evolutionary pathways are suggested to account for this star's high luminosity. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Little has been written in the literature on women's career or identity development specifically addressing the experiences of women artists. Yet there is reason to believe that these women, by virtue of their gender and their career choice, may have a particular perspective on how career is understood and lived that differs from that of the majority of women and men who have chosen more traditional career paths. This qualitative study investigated the meaning and experience of career for eight women artists over age 40 from the visual, performing, and literary arts. The methods of inquiry and data analysis were based on a phenomenological approach. The researcher conducted three in-depth interviews with participants over a two-year period. Nine common themes, an account of what the term "career" meant to participants, and the fundamental structure-or common story-of the participants' experiences of career over their life span were drawn from the interview data. These nine themes are: (1) Sense of being an outsider; (2) Sense of validation through external recognition; (3) Sense of being obstructed; (4) Sense of being torn between the needs of self and others; (5) Sense of connection and belonging through art; (6) Sense of struggle to assume the identity of artist; (7) Sense of selfdetermination; (8) Sense of being a pioneer; and (9) Sense of harmony between self, art, and career. All of the participants indicated some degree of discomfort with the concept of career. They perceived their work as artists to be closely related to the sense of self and preferred to talk about their "lives as artists" and about "being artists," rather than about "having careers" as artists. The findings of this study contribute both to our understanding of how women artists conceptualize and experience their careers over the course of their lives and to our knowledge of how they develop their identities as artists within the context of their careers. These findings led to specific recommendations for research and practice in the area of women artists' career development. / Education, Faculty of / Educational and Counselling Psychology, and Special Education (ECPS), Department of / Graduate

Canada is the largest exporter of softwood lumber in the world. Sapstain caused by fungi is a costly problem for the Canadian lumber industry. To maintain and increase future sales and exports of lumber requires not only effective, but also environmentally acceptable anti-sapstain methods. A thorough understanding of the physiological and biochemical features of sapstaining fungi should facilitate the development of new methods of protection. This work was carried out to determine the available lipid nutrients in wood and to understand the biodegradation mechanisms of lipids by sapstaining Ophiostoma species. Lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) constitutes the greatest volume of wood harvested in British Columbia. As with all wood species, the freshly sawn sapwood is susceptible to sapstain. The total extractives content in the sapwood at the breast height of a 35-year-old lodgepole pine tree was 1.9-2.2% of oven dry weight, which included 1.1-1.3% triglycerides (TG), 0.02-0.03% free fatty acids (FA), 0.3-0.4% free resin acids (RA), and 0.15- 0.21% steryl esters and waxes (SEAV). A considerably higher content of extractives was present in heartwood, i.e., 9.7-12.4%, including 0.6-0.7% TGs, 0.8-1.1% free FAs, 4.0-5.6% free RAs, and 0.25-0.33% SE/Ws. The wood TGs were composed mainly of oleic (18:1), linoleic (18:2), linolenic (18:3) and palmitic (16:0) acids. The dominant RA was palustric acid, followed by abietic, neoabietic, dehydroabietic, isopimaric, pimaric, and sandaracopimaric acids. The ability of three sapstaining fungal species, Ophiostoma piceae 387N, O. ainoae 701 A, and O. piliferum 55H to degrade and utilize the major lipids in the sapwood of lodgepole pine and trembling aspen (Populus tremuloides Michx.) was investigated. The fungal growth rate in wood was monitored by quantifying ergosterol extracted from colonized wood. After two weeks colonization, the TGs in wood were degraded by 50% to 80%, which resulted in an accumulation of free FAs in the wood. Lipases (glycerol ester hydrolases, EC 3.1.1.3) are the enzymes responsible for hydrolyzing TGs into glycerol and FAs which are assimilable by fungal cells. Extracellular lipase activity of O. piceae 387N was detected both in colonized wood and in liquid culture. The effect of various factors (carbon sources, nitrogen sources, and medium pH) on the growth and lipase activity of O. piceae 387N were examined in liquid culture. The extracellular lipase secretion was enhanced in the presence of triglycerides. The composition of a medium was optimized for a high extracellular lipase production, which contained 2% olive oil as a carbon source and 0.5% ammonium sulfate and 3% peptone as nitrogen sources with an initial medium pH of 5.0. A major extracellular lipase was purified from the liquid culture filtrates of O. piceae 387N by hydrophobic interaction chromatography and anion exchange chromatography. This lipase was characterized as a monomer with a molecular weight of 35 kDa, and was glycosylated, containing 10.1% carbohydrates. It was resolved as a single band on SDS-PAGE (sodium dodecyl sulfate- polyacrylamide gel electrophoresis) gels, whereas 3 bands at pi's 4.3, 4.1 and 3.8 were observed on LEF (isoelectric focusing) gels. Lipolytic stain demonstrated that the three bands on IEF gels were lipolytically active. The 3 isoforms were found to have a same N - terminal sequence as D¹-V²-S³-V⁴-T⁵-T⁶-T⁷-D⁸-I⁹-D¹⁰-A¹¹-L¹²-A¹³-F¹⁴-F¹⁵-T¹⁶-Q¹⁷-W¹⁸-A¹⁹-G²⁰. The purified O. piceae 387N lipase was stable at pH's 4 to 8 and at temperatures below 40°C. The pH and temperature optima for activity were approximately pH 5.2 and 30°C, respectively. Enzyme activity was not influenced by N-ethylmaleimide, P-mercaptoethanol, and dithiothreitol, was slightly enhanced by Ca²⁺ and Mn²⁺, and was severely inhibited by Hg and Fe³⁺, diethyl pyrocarbonate, diethyl /?-nitrophenyl phosphate, butyric acid, caproic acid, and SDS. The lipase showed high specificity toward substrates with intermediate and long chain FA residues, and belonged to a group of 1(3) positional specific lipases. The rate of hydrolysis of the lipase toward a triglyceride (l,3-dipalmitoyl-2-oleoyl-glycerol) was 25-50 fold higher than that toward the waxes (oleyl esters) and cholesteryl esters. Finally, it was conclusively shown that the purified lipase could effectively release fatty acid residues from the triglycerides isolated from wood. The data and information obtained in this work have contributed to the understanding of the physiological and biochemical features of sapstaining Ophiostoma species. The large amounts of various lipids in wood, in particular TGs and FAs, are important carbon and energy sources for the sapstaining fungi, which are capable of secreting extracellular lipases to degrade TGs. The information implies that the growth of sapstaining fungi may be hindered by disrupting the metabolic processes of lipid utilization, or by applying biological competitors which are more efficient in assimilating lipids and other nutrients in wood. / Forestry, Faculty of / Graduate