title: The Understanding and Significance of the "Remnant" in Qumran Literature: Including a Discussion of the Use of this Concept in the Hebrew Bible, the Apocrypha and the Pseudepigrapha

contributor:
Sanders, E. P.
Religious Studies

subject:
Religious Studies
Religion
Religion

abstract:
The aim of this dissertation is to examine the Qumran covenanters' understanding of the remnant to test the common scholarly belief that the sectarians considered themselves to be the eschatological remnant. That the sectaries had a remnant understanding is a pre-supposiiion validated by the frequent remnant statements both explicit and implicit. Hence, the question becomes how they understood themselves vis-à-vis the remnant. This question, however, is not the only issue which must be discussed. The pre-Qumranian Palestinian understanding of the remnant must be examined because the sectarians' mindset must be understood against the backdrop of their intellectual heritage.

Contrary to the opinion of most scholars, this study concludes that the Qumran sectaries understood themselves not as the eschatological remnant, but rather as its proleptic representatives. Thus the historical sect is not to be equated with the eschatological sect. Membership in the former did not guarantee membership in the latter and membership in the latter was attainable without membership in the former. On the one hand, although one who joined the historical sect and remained steadfast would become a member of the eschatological sect, the determination could not be assured until the end of time. On the other hand, the ranks of the eschatalogical sect would be increased by a final conversion to the sectarian covenant at the eschaton.

With respect to significance, this study clearly shows that the concept of the remnant as understood at Qumran formed a major part of the sectarians' self-understanding.

In 1QS, CD and 1QH the remnant consciousness is focused upon the historical sect and consists in the realization that, as part of Israel and, therefore, as the children of the historical Israel, the sectarians understood themselves as descen- dants of numerous historical remnants saved by God from various catastrophes. At this time, the sect understood itself as a part of Israel. This is evident both from the fluidity of membership in the historical sect and from the sectarian designation of non-sectarians as Israelites. Although the sect did have a covenant which required that the adult make a conscious decision to join and within which was found salvation, it nonetheless remained true that the title Israel was not appropriated by the historical community.

In lQM, lQSa and other predominantly eschatological texts, the vision is of the eschatological sect. All nonsectarian Israelites who did not convert would be destroyed as would the Gentile. Those left would be definable, therefore, as both Israel and the remnant of Israel,--the former because they alone would be those entitled to be called Israel; the latter because they alone had been saved from Israel. The remnant understanding of the Qumran sectarians is shown to be consistent with t he understanding inherited by them. The correct understanding of the Qumran remnant lies, therefore, in a comparison with its Jewish heritage.

abstract: Doctor of Philosophy (PhD)


title: Muddy Waters: Conservation Discourse and the Politics of Power in Marine Park Co-Management in Belize

contributor:
Fen, Harvey A.
Anthropology

subject: Anthropology Anthropology

abstract:
This research examines the complex local-national-global power dynamics that are a part of marine protected area (MPA) co-management in Belize using Friends of Nature (FON) a local NGO that manage two MPAs along the southern coast as an example. The first part of the thesis consists of a description and evaluation of marine conservation in Belize and the Friends of Nature experience thus far. The chapers document the system of MPA co-management in Belize, highlighting the distribution of power and authority between local national and global stakeholders involved in the process. In reviewing FON's management activities and its interactions with the communities it represents, I suggest a new way of understanding the notion of local empowerment as a component of co-management, lessons usefully shared, as well as areas for improvement.

Part Two takes a more theoretically critical perspective on this experience, offering a different evaluation of the policies of marine conservation intervention. The chapters extent Part One's evaluation, but I shift the focus toward the discurve context in which co-management operates in one village, Placencia. The analysis presents the process-as a contested conceptual project in which local fishers' and global conservation organizations' notion of conservation come into conflict. The matrix of connections between global and local actors indicates that through a powerful conceptual apparatus, conservation discourse is not necessarily dominant. In many ways, fisher actively contested. In doing so they engage these discursive constructions of ecological problems and solutions by participating in FON in a highly strategic manner. This ultimately results in a continusouly shifting assortment of gains and deficits for all co-mangement participants, and highlights the limitation of positioning co-management as either 'empowering' or co-opting of local stakeholders.

abstract: Doctor of Philosophy (PhD)


title: Sex chromosome and sex determination evolution in African clawed frogs (Xenopus and Silurana)

contributor:
Evans, Ben J
Biology

subject:
sex chromosomes
sex determination
systematics
pipid frogs
evolution
bioinformatics
Evolution
Evolution

abstract: Sex chromosomes have evolved independently multiple times in plants and animals. Sex chromosome evolution theory predicts the gradual degeneration of the sex-specific sex chromosome due to suppression of recombination, which lowers the efficacy of natural selection. Suppressed recombination also acts to resolve sexual conflict and ensure proper segregation of sex-specific alleles. However, sex chromosome degeneration is not always the case, and evolutionarily old, and young, but homomorphic (nondegenerate) sex chromosomes have been observed. African clawed frogs (Xenopus and Silurana) have homomorphic sex chromosomes due to a recent turnover event. However, occasional recombination between the sex chromosomes may contribute to the maintenance of homomorphic sex chromosomes in African clawed frogs. Mechanisms that prevent divergence of sex chromosomes may be related to polyploidization, which is frequently observed in African clawed frogs. The studies herein construct a phylogenetic framework to test alternative hypotheses for selection on sex-linked and autosomal genes involved in sex determination, map sex chromosomes and compare sex chromosomes across African clawed frogs. I have also explored the relationship between phenomena like recent turnover events, recombination and polyploidization to sex chromosome degeneration (or lack thereof). In this dissertation, I have discussed the potential for multiple mechanisms of sex determination and the unique pseudoautosomal nature of sex chromosomes within this group of frogs. This body of work provides a comprehensive study of sex chromosomes in a group lacking phylogenetic resolution and sheds light on the origin and evolution of sex chromosomes in other organisms.

abstract: Doctor of Philosophy (PhD)


title: Structural Disjoining Potential of Grain Boundary Premelting in Aluminum-Magnesium via Monte Carlo Simulations

contributor:
Hoyt, Jeff J.
Provatas, Nik
Gaulin, Bruce
Physics

subject:
Monte Carlo
Grain Boundary
Premelting
Disjoining potential
semi-grand canonical ensemble
embedded atom method
binary alloy
Metallurgy
Metallurgy

abstract: Premelting is the formation of a thin, thermodynamically stable, liquid-like film at an interface for temperatures below the equilibrium melting temperature. Using a Monte Carlo technique, the underlying short range structural forces for premelting at the grain boundary can be directly calculated. This technique is applied to a (i) Σ9 ⟨115⟩ 120o twist boundary and a (ii) Σ9 ⟨011⟩ {411} symmetric tilt boundary in an embedded atom model of Aluminum-Magnesium alloy. Both grain boundaries exhibit disordered structures near the melting point that depend on the concentration of Magnesium. The behavior is described quantitatively with sharp interface thermodynamics, involving an interfacial free energy that depends on width of the grain boundary, referred to as the disjoining potential. The disjoining potential calculated for boundary (i) displays a decreasing exponential dependence on width of the grain boundary, while the disjoining potential of (ii) features a weak attractive minimum. This work is discussed in relation to a previous study using pure Nickel, results of which can be useful to the theoretical study of thermodynamic forces underlying grain boundary premelting in an alloy.

abstract: Master of Science (MSc)


title: Body/Work: Aspects of Embodiment and Culture in Samoa

contributor:
Rodman, Wm.
Anthropology

subject: Anthropology Anthropology

abstract: The body is a central reality of culture and a fundamental site at which culture is expressed, in action and in thought. Yet the body has not been systematically recovered by culture theory, because the body has usually been considered solely as an artifact of culture. In this text I argue that the body needs to be understood as the key site at which and through which culture is made possible, as an ongoing process of embodiment. Based on one year's fieldwork in Western Samoa, I describe some of the everyday practices through which embodiment is carried out as a culture-making process, and offer an outline of some basic propositions for a model of embodiment, as one way of making the body a central analytic issue in future developments in Anthropological theory. By linking everyday embodying practices with Samoan concerns for dignity, humility, and strength, I argue for a different way of looking at bodies, one which locates the body as a process of awareness and enactment, and not simply a thing culture acts upon.

abstract: Doctor of Philosophy (PhD)


title: Four Essays on the Theory of Monetary Policy

contributor:
Scarth, William M.
Economics

subject: Economics Economics

abstract:
This dissertation focuses on the construction of macroeconomic models that can be used to evaluate monetary policy. The theoretical models dewloped for this purpose emphasize the importance of intertemporal optimizing behaviour, the role of expectations and nommal price rigidities.

The first essay (chapter 2) compares the implIcations of the interest rate channel and the cost chamlel (when firms' marginal cost depends directly on the nominal interest rate) of the monetary policy transmission mechanism under inflation and price-level targeting regime for determining the optimal trade-off between stabilizing inflation and the output-gap in a forward-looking closed-economy model. In contrast to the traditional literature. which focuses only on the interest rate channel, research presented In chapter 2 demonstrates that the demand shocks cannot be completely stabilized with inflation targeting when the cost channel is operative: the central bank faces an inflation outputgap stabilIzation trade-off. Moreover, it is shown that there are gains (In terms of reduced expected losses for the central bank) to be made from conductIng monetary policy With commitment rather than in a discretionary fashion even if there is no inflation bias. Also. these gains are larger In the presence of cost charmeL so there is a stronger case for commitment.

Furthermore. building on the notion that it is difficult to conduct monetary policy with full commitment due to practical considerations, chapter 2 seeks an answer to the question: Is it possible to replicate the results of inflation targeting under commitment with pnce-Ievel targeting under discretion? The results in chapter 2 confirm the earlier results that it is possible. However, it also points out that the results need to be interpreted carefully in the presence of the cost channel. In particular, the relative weight on outputgap stabilization versus inflation stabilization needs to be appropriately adjusted in comparing the expected value of the losses incurred in the two regimes: otherwise the results could be dIfferent.

Chapter 2 also proposes an altemative method of calculating the implicit interest rate rule that implements the optimal policy. Unlike the existing literature, this method correctly depicts the mertial behaviour of optimal policy with commitment and derives conditions that can avoid indeterminacies of output and inflation. Moreover, in the presence of the cost channel. this method is the only correct method in the commitment case for the sake of intemal consistency of results.

The second essay (chapter 3) uses continuous-time modeling approach instead of the more conventional discrete-time approach and compares the performance of two rulebased targeting regimes --- price-level targeting and nominal income targetmg with and without the cost channel of monetary policy of a closed economy. Chapter 3 considers a senes of macroeconomic models with different specifications for both the aggregate demand side and the aggregate supply side of the economy to check for robustness of results. It is assumed that the two targetmg regimes generate the same outcome regardmg long-term inflation. Thus, the criterion for evaluating the performance of a monetary regime is its ability to minimize the volatIlity in real output in response to aggregate demand shocks.

The main result of chapter 3 is that the cost channel matters in the sense that the volatilIty of real output increases under both price-level and nominal income targetmg when the cost channel is included in the models. However, the inclusion of the cost channel does not say much on the choice between the two regimes. It appears that nominal income targeting performs better than price-level targeting in bringing down the volatility of real output in almost all the specifications of the macro models used in the analysis regardless of the cost channel.

Using the type of models analyzed in chapter 3, chapter 4 introduces open economy considerations and looks at the performance of monetary policy (in terms of reducing volatility in real output) under three altemative targeting regimes: exchange rate targeting (fixed exchange rates), price-Ievel targeting, and nominal income targeting (both flexible exchange rate options). Although the supply-side effects of the interest rate (the cost channel) are Ignored, the supply-side effects of exchange rate changes (due to the existence of intermediate imported inputs) are highlighted.

Under these settings, chapter 4 explores the impact of an increased degree of price flexibility on the volatility of real output. Chapter 4 finds support for Keynes' concern that under a flexible exchange rate regime a higher degree of price flexibility can raise output volatility. This result is consistent with central banks that argue that their low inflation-flexible exchange rate policy has increased contract length and so decreased the degree of nommal price flexibility. Chapter 4 also finds support for central banks that favour fIxed exchange rates. A fixed exchange rate regime implicitly Implies that the economy is willing to accept structural refonns of the sort that promote flexibility m prices to absorb the effects of shocks. Chapter 4 shows that with fixed exchange rates output volatility indeed goes down as a result of increased price flexibility. Thus, there is internal consistency within both views about exchange rate polIcy.

Chapter 5 develops a discrete-tIme dynamic stochastic general equilibrium model with incomplete asset markets. nominal pnce rigidities and monopolistic competItion to shed light on the role of the exchange rate and its relation with current account dynamics and domestic inflation in the formulatton of monetary policy. Chapter 5 argues that the assumption of complete asset markets is not realistic in a model with imperfections and ngidities in goods market because, with nominal rigidities, monetary polIcy wlll affect real variables including the current account. With incomplete asset markets the dynamics of current account does matter for monetary policy because then, besides dealing with the dIstortions created by monopolistic competition, the central bank needs to address the inefficiencies caused by incomplete asset markets.

The main result of chapter 5 is the breakdown of a widely accepted result that optimal monetary policy for an open economy calls for adjusting the interest rate to completely offset demand shocks. which imphes no trade-off between output volatility and inflation volatility. Due to the direct effect of real exchange rate on domestic inflation. the optimal monetary policy calls for trading-off some output volatility for less inflation volatility. Moreover, due to the dynamIcs of current account it entails a response to variations in the net foreign asset position, since this mechamsm makes the impact of the demand shock last well beyond the time interval for which prices are rigid.

abstract: Doctor of Philosophy (PhD)


title: Political and Religious Transition in Medieval South India and Sri Lanka

contributor:
Sivaraman, K.
Younger, P.

subject: History Religion History

abstract:
The two most important ordering principles for human society are the political and the religious. In some way, the history of a society might be viewed as the process with which a community attempts to affirm, through religious oncf political structures and values, the legitimation of its power and authority. Successive efforts to weave new patterns of legitimation might then be thought to define the process of change in that society. As traditional forms of society succumb to new means of ordering reality the changes that come about raise the question: What happens to a community's ordering of reality when it attempts to redefine its political legitimizing process in terms of its religious orientation? The purpose of this thesis is to examine this question in the related societies of South India and Sri Lanka.

The process transforming society is not a simple evolution of new ideas and the breakdown of older ideas. Instead the process is more likely a dialectic of critical thought in which a common horizontal thread (politicoreligious man) entwines with a series of vertical threads linking that society with its past traditions. The vertical threads are those by which a society establishes the relation of its system of thought to previous expression in the same branch of cultural activity (religion, politics, philosophy). By the horizontal thread a society critically assesses its legitimizing values in terms of what is appearing in other branches of cultural activity and in terms of values in other societies. South India and Sri Lanka stand out in the deqree to which they exemplify this historical process of shaping and transforming the mechanisms of the social order. The lattcer religious tradition, as it is expressed in the historiography of the chronicles, the Dῑpavamsa, the Mahᾱvamsa and the Cῡlavamsa is portrayed as an ideal society that does define itself against the past (the South India Brahmanic influence and its basic political and social institutions), but quite selfconsciously identifies it self as a transformation and extension of the older tradition. The subtleties of such a transformation are exemplified by the normative pattern for Sinhalese kingship provided in what Tambiah and B. Smith have called a "paradigm of kingship", the Asokan concept of Dharmaviiaya. This concept of kingship is central to the idea of social order in Anuradhapuro, Sri Lanka and its political legitimation process differs markedly from South Indian concepts of kingship even though it shores the some origin.

The Sri Lankan conceptualization of what a state should be appears to be a remarkable break from the political and religious tradition in mainland India. The design of Sri Lankan statehood differs in that it is schism-preventing or monistic. Virtually all aspects of Sri Lankan society appear to revolve around a fear of disorder and disruptive forces. The ideal social order in Sri Lanka is rooted in this concern. This perspective is in direct contrast to Chola concepts of the state which can be called non-centralized or pyramidally segmented. Burton Stein puts forward in his book Peasant State and Society in Medieval South India, the idea of the segmented state in which each level of political organization stands in opposition to each other inviting rivalry and dispute between lesser political leaders (Nadu chieftains in order to legitimize the soveriegnty of the king. This system appears lo be in marked contrast to the Sri Lankan political theory which disunity is considered tantamount to chaos. In the Cholan segmentary state unlike in Ceylon) there are two kinds of centres in both the conceptual and empirical sense.

As to the first sense) the segmentary state exists as a state only insofar as the segmentary units comprising it (Nᾱdus) recognize a single ritual authority -- the king. This recognition provides some legitimacy for the nodus which are in themselves centres in the second sense. In a segmentary state) politicol control is appropriately distributed among many throughout the system) ritual supremacy is legitimately conceded to a single centre. In the Cholan state) the king (dēva-rᾱja) as protector of the social order sacrificially attains divinity and becomes Siva incarnate. Ritually incorporative kingship of this kind provides the ritual focus for balanced and opposed internal groupings.

In the Sri Lankan state there is on amalgamation or absorption of iocalized chieftainships so that they lose their essential being as smaller parts of a political whole. Hence, ritually incorporative kingship in Sri Lanka does not exist at the some incorporative level of organization as in the Chola state.

abstract: Master of Arts (MA)


title: Rotational Rheometry of Liquid Metal Systems: A Study with Al-Si Hypoeutectic Alloys

contributor:
Hamed, Mohamed
Shankar, Sumanth
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract: [blank pages: 18, 38, 54 & 70]

abstract: Rheological property such as shear viscosity and flow curve for metallic liquid systems has been evaluated. Pure Al, pure Zn, Sn based solder alloy and various compositions of Al-Si hypoeutectic binary alloys were the metallic systems included in the study. The effect of 0.023 wt % Sr edition to various compositions of Al-Si composition and shear rate experience by the liquid. A rotational rheometer was developed with a high temperature environmental furnace for this study. Three types of measurement geometry were evaluated: cone and plate, Din Coaxial and Double Concentric Cylinder (DCC). The DCC geometry has been proposed as the most practical geometry for liquid metal viscosity measurement in rotational rheometer. Analytical solution to evaluate viscosity with the rotational rheometer equipped with DCC measurement has been proposed. Further, the critical maximum allowable angular velocity for reliable viscosity evaluation has also been proposed for this system. It has been concluded that contrary to popular belief, liquid metal systems are non-Newtonian and shear thinning fluids. The effect of Si on the viscosity of Al-Si hypoeutectic alloys have been quantified as a function of shear rate and melt super heat temperatures. Further, it has been concluded that Sr additional to Al-Si alloys significantly alters the viscosity and the melt at low melt super heat temperatures.

abstract: Master of Applied Science (MASc)


title: Gender and Status Representation in Northwest Coast Burials

contributor:
Cannon, Aubrey
Archaeology

subject:
Archaeological Anthropology
Archaeological Anthropology

abstract: I apply a contextual analysis to the mortuary data of the Northwest Coast between ca.6000- 1000 BP to show that there are visible temporal and spatial patterns relating to the ways males and females are represented in burials. I have colleted and analyzed the data from 1044 individual burials from 45 burials sites from the north, south and central regions of coastal British Columbia. I examined variables including: burial mode: position of the body: type of interment and the types of grave goods in relation to gender and age groups. The differences between male and female burials are most reflected by the type of grave good(s) and the frequency and type of interment. Although there is no patterning among the burials from the Northwest Coast as a whole, gender-based differences in mortuary treatment are clearly evident within and between regions when the scale of analysis is reduced.

abstract: Master of Arts (MA)


title: Social Change and Political Stability in Ontario: Electoral Forces 1867-1977

contributor:
Jacek, Henry
Political Science

subject:
Political Science
Political Science

abstract:
In the years since Confederation, Ontario seems to have undergone profound social change, yet it seems also to have experienced relatively little political change. This apparent paradox is the starting point of this thesis. The initial terms of reference thus centre on change processes, but considerable attention is devoted to continuity and to stability in both the social and political arenas.

Reduced to the simplest terms, the aim of this work is to determine what the relationship has been between social change and political change in Ontario over the past century. Although it is recognized that a good deal more is involved, elctions and electoral forces are chosen as gauges of the interplay of social and political change. The empirical analysis consists of detailed examination of election returns and of cencus data, employing techniques both elementary and moderately sophisticated. In addition to the specific findings, the data set generated for these purposes represent in itself a significant contribution to knowledge of Ontario politics.

As a complement to the statistical an analysis, a wide-ranging review was conducted of Ontario history. Based on secondary sources, this review of social and political developments in the province not only provides a context for the statistical analysis, but also brings into consideration aspects of social, political and electoral continuity and change which do not lend themselves to statistical enquiry. A key element here is the province's enduring "progressive conservatism" which is examined and related to change processes.

The findings of this study may be arrayed along four dimensions. First, no startling or grand new interpretations of Ontario politics emerge. Secondly, a host of new facts and insights on particular aspects of Ontario politics and society. Thirdly, ina a number of instances, the conventional wisdom of Ontario electoral history proves an either incomplete or inaccurate guide; this is particularly so with respect to commonly accepted interpretations of politics in the Nineteenth Century. Finally, a number of middle range hypotheses relating social and political change are tested in the context of Ontario history. The initially appearing notion of critical realignment, for example, is found to have at best limited applicability to Ontario. Some evidence is adduced in support of John Wilson's theory of political development, but important shortcomings emerge as well.

In the end, the rather simple-minded paradox posited at the outset is largely dispelled by a more thorough understanding of the complexities of the social change-political change relationship in Ontario. The following are the key elements of this fuller view of the relationship: no significant social change has failed to effect lasting, substantial political and electoral changes. Conversely, no important, enduring political or electoral changes have come about save in response to social change. This transformation of social change into change in the electoral and political realms has been uneven and at less pronounces levels of change, uncertain-for a host of reasons: somd of the changes in Ontario society have been more apparent than real, while others have lacked political; not all political changes have been manifested electorally; the parties and their leaders perform a crucial transmission role, yet they also exert an important independent influence; the province's diversity and its constituent communities have also had a telling effect, as has its social and political converatism.

abstract: Doctor of Philosophy (PhD)


title: Thermodynamics and Kinetics for the Pearlite Reaction in Chromium Steels

contributor:
Kirkaldy, J.S.
Metallurgy

subject: Metallurgy Metallurgy

abstract:
The phase equilibria in the Fe-C-Cr system, essential for the understanding of the pearlite reaction in low chromium steels, has been calculated from the thermodynamic data. The experimentally determined tie-lines are in good agreement with the calculated phase diagrams.

The pearlite growth rates and interlamellar spacings in a series of low chromium Fe-C-Cr alloys have been experimentally determined. The growth rates in these alloys are explained in terms of chromium partitioning and chromium phase boundary diffusion control at low supersaturations and in terms of the local equilibrium no-partition mechanism and carbon volume diffusion control at high supersaturations.

The relative effect of Cr, Mn, and Ni on the pearlite reaction is qualitatively discussed in terms of the above mechanisms, established for the chromium steels. The results have an application to the hardenability problem in steels.

abstract: Doctor of Philosophy (PhD)


title: Discours Officiel et Discours Immigré au Québec Continuité ou Rupture

contributor:
Ahmed, Maroussia
French

subject: French and Francophone Language and Literature

abstract: Cette thése fait une mise en rapport entre Ie discours officiel du Québec et Ie discours fictif qui émane de la littérature des communautes culturelles au Québec afin d'expliquer Ie decalage qui existe entre eux. Nous tentons de démontrer dans quelle mesure la politique québécoise a réellement accepté les communautés culturelles comme faisant partie intégrante de la collectivité et de I'identité québécoise. Nous démontrons que la politique culturelle du Québec est démocratique dans la mesure où elle accorde les mêmes droits fondamentaux à tous les membres de la société québécoise. Néanmoins, nous soutenons que la marginalisation ressentie par les communautés culturelles et exprimeée dans leur littérature indique que Ie Québec n'est pas la démocratie participante et pluraliste quelle affirme être dans Ie discours officiel. Par ailleurs, I'occultation des communautés culturelles du projet collectif québécois est rendue plus profonde par la presence d'un discours officieux nationaliste qui envisage un Québec indépendant fondé exclusivement sur la culture «de souche» francophone. Le discours officiel serait donc une expression d'une volonté plus que d'une réalité.

abstract: Master of Arts (MA)


title: NEGATIVE DIELECTRIC CONSTANT OF PHOTO-CONDUCTING POLYMERS UPON CORONA-CHARGING

contributor:
Xu, Gu
Klenkler, Richard
Kitai, Adrian
Materials Science and Engineering

subject:
negative dielectric constant
static electricity
photoconductor
spiral impedance curve
coil-less inductor
Polymer and Organic Materials
Polymer and Organic Materials

abstract:
The phenomenon of image blurring on laser-printed or electro-photocopied paper has been discovered since the 1980s. In the 1990s, the problem was confirmed to be associated with the undesired surface conduction along the unique photoconductive polymer surface during the photoconduction process. Other than this, little progress has been made in investigating this phenomenon, due to the limited experimental techniques.

In this thesis, the electrical properties of a commercially available photoconductor as a result of Corona charging were studied. Various techniques including vacuum deposition and step-function impedance spectroscopy were employed, to overcome the nature of the photoconductor that prevented the use of conventional techniques such as AC impedance spectroscopy. Negative dielectric constant (NDC) has been prevalently discovered at a broad range of frequencies (below 1Hz and up to 1 MHz) and it was questioned in the form of a physically-impossible inductor. This precipitous sign switch of dielectric constant is found in various areas ranging from physics, chemistry, biology to electronics. The magnitude of the NDC decreased drastically with the decrease of electric field frequency. The system obeyed the proposed free-carrier plasma model with a resonance frequency at MHz level.

Commercially available polymeric photoconducting materials showing NDC at extremely low frequency are expected to provide unusual scattering to electromagnetic waves and therefore demonstrate profound implications with reduced cost. It has paved the way for many applications such as inductors in integrated chips without bulky coils and provides an insight into a possible revolution in electronics and photonics.

abstract: Doctor of Philosophy (PhD)


title: Software Specialization as Applied to Computational Algebra

contributor:
Farmer, William M.
Computing and Software

subject:
Computational Algebra
Software Specialization
Metaprogramming
Coge Generation
Buchberger's Algorithm
Theory and Algorithms
Theory and Algorithms

abstract: A great variety of algebraic problems can be solved using Groebner bases, and computational commutative algebra is the branch of mathematics that focuses mainly on such problems. In this thesis we employ Buchberger's algorithm for finding Groebner bases by tailoring specialized instances of Buchberger's algorithm via code generation. We introduce a framework for meta programming and code generation in the F# programming language that removes the abstraction overhead of generic programs and produces type-safe and syntactically valid specialized instances of generic programs. Then, we discuss the concept of modularizing and decomposing the architecture of software products through a multistage design process and define what specialization of software means in the context of producing special instances. We provide a domain-specific language for the design of flexible, customizable, multistage programs. Finally, we utilize the aforementioned techniques and framework to produce a highly parametrized, abstract and generative program that finds Groebner bases based on Buchberger's original algorithm, which, given all the proper definitions and features of a specific problem in computational algebra, produces a specialized instance of a solver for this problem that can be shown to be correct and perform within the desired time complexity.

abstract: Doctor of Philosophy (PhD)


title: EFFECTS OF DH31, DROSOKININ, AND ALLATOSTATIN A ON EPITHELIAL K+ TRANSPORT AND TISSUE CONTRACTIONS IN THE GUT OF LARVAL DROSOPHILA MELANOGASTER

contributor:
O`Donnell, Michael J.
Campos, Ana R.
Biology

subject:
Drosophila melanogaster
diuretic hormone
drosokinin
allatostatin
ion transport
water balance
Biology
Biology

abstract: DH31 and drosokinin are known promoters of fluid secretion in Drosophila Malpighian tubules, while the effect of allatostatin A on Malpighian tubule fluid secretion is unknown. The expression of these peptides and their receptors is widespread in the larval gut and central nervous system. The scanning ion-selective electrode technique (SIET) was used to measure changes in epithelial K+ flux in the gut as a proxy for the flow of osmotically-obliged water between the gut lumen and the haemolymph. The primary goal of this study was to investigate the effects of DH31 and drosokinin on the gut as an indicator of coordination of diuretic activity between this tissue and the Malpighian tubules. Such coordination, whereby Malpighian tubule fluid secretion is stimulated concomitantly with fluid uptake by the gut, would be physiologically essential for the maintenance of haemolymph volume and osmolarity. Secondarily, this study sought to characterize the function of allatostatin A with respect to its effect on gut K+ transport. DH31 stimulated K+ absorption across the anterior midgut epithelium and reduced K+ absorption in the middle midgut copper cell zone. Drosokinin increased K+ absorption across the anterior midgut epithelium and was also stimulatory in the posterior midgut neutral zone. Allatostatin A stimulated K+ absorption across the epithelia of the anterior midgut and middle midgut copper cell zone, but was inhibitory in the large flat cell zone. The larger surface area of the anterior midgut relative to the middle midgut means that all three peptides were likely net stimulators of K+ uptake. The reduction in K+ absorption in the middle midgut by DH31 and allatostatin A may relate to a redistribution of fluid uptake among the regions of the midgut to preserve lumenal pH. DH31 and drosokinin also independently increased the contraction frequency of the anterior midgut, while the contraction frequency of the pyloric sphincter was increased by combined application of both peptides. Stimulation of gut contractions has previously been attributed to these and other diuretic factors in insects. The findings of this investigation implicate DH31, drosokinin, and allatostatin A in the stimulation of midgut K+ absorption, which may suggest a role for these peptides in altering fluid transport across this epithelium in larval Drosophila.

abstract: Master of Science (MSc)


title: Shake table Seismic Performance Assessment and Fragility Analysis of Lightly Reinforced Concrete Block Shear Walls

contributor:
El-Dakhakhni, W. W.
Tait, M. J.
Civil Engineering

subject:
Concrete Block Masonry
Shake Table Tests
Shear walls
Displacement Ductility
Analytical Fragility Analysis
Analytical Modeling
Structural Engineering
Structural Engineering

abstract: This thesis reports on shake table tests on fully-grouted reinforced masonry (RM) shear walls. The test walls covers a range of design parameters to facilitate benchmarking, a thorough performance investigation, and calibration of numerical models as well as development of fragility curves within the context of Performance Based Seismic Design (PBSD). The details of the experimental program undertaken, including general observations in terms of cracking patterns and failure modes of the tested walls and the results on the lateral strength, hysteretic response, dynamic properties, and the contribution of different displacement components to the response of the walls, are presented. More detailed analyses include seismic performance quantification of the walls in terms of inelastic behaviour characteristics, various energy components, and the effective dynamic properties of the tested walls. The analysis is concluded with development of simplified nonlinear response history analytical models and seismic fragility assessment tools for the tested walls. In general, the study results indicated that the displacement ductility capacity of the RM walls and their capability to dissipate energy through plastic hinging are higher than what is currently recognized by the National Building Code of Canada (NBCC). The fragility assessment study further indicated that similar walls are expected to conform to the current drift limits of the NBCC even at high seismic regions in Canada. The results of this study are expected to contribute to the growing Seismic Performance Database (SPD) of RM Seismic Force Resisting System (SFRS), and to the understanding of the lightly reinforced masonry wall system behaviour.

abstract: Master of Applied Science (MASc)


title: Using Reputation in Repeated Selfish Routing with Incomplete Information

contributor:
Karakostas, George
Computing and Software

subject:
Selfish Routing
Repeated Game
Incomplete Information
Reputation
Theory and Algorithms
Theory and Algorithms

abstract:
We study the application of reputation as an instigator of beneficial user behavior in selfish routing and when the network users rely on the network coordinator for information about the network. Instead of using tolls or artificial delays, the network coordinator takes advantage of the users' insufficient data, in order to manipulate them through the information he provides. The issue that arises then is what can be the coordinator's gain without compromising by too much on the trust the users put on the information provided, i.e., by maintaining a reputation for (at least some) trustworthiness.

Our main contribution is the modeling of such a system as a repeated game of incomplete information in the case of single-commodity general networks. This allows us to apply known folk-like theorems to get bounds on the price of anarchy that are better than the well-known bounds without information manipulation.

abstract: Master of Computer Science (MCS)


title: The Structural Disjoining Potential of Grain Boundary Premelting in Binary Alloys using Phase Field Crystal Model

contributor:
Provatas, Nikolas
Hoyt, Jeffrey
Zurob, Hatem
Materials Science

subject:
premelting
disjoining potential
alloy
grain boundary
phase-field crystal
Structural Materials
Structural Materials

abstract: A framework is described using the phase-field crystal model for the study of premelting in binary alloys through short-range interfacial interactions that arise from the structure of grain boundaries. A nonconserved model A formulation of PFC was used to model grain boundaries in two dimensions for several different angles of misorientation: 27.8, 21.8, 17.8, 13.2, and 5 degrees. The character of the premelting transition, whereby a liquid-like film develops at a defect at temperatures below the melting point, changed with misorientation angle. An excess mass over the grain boundary can be defined as an analog to the liquid layer thickness due to premelting. It is found that low-angle grain boundaries remain at a relatively constant value of excess mass, and indeed can remain solid above the melting point. High-angle grain boundaries have a logarithmically increasing width that diverges at the melting point. A width-dependent energy can be defined called the disjoining potential that takes into account structure, interfacial and bulk energies to describe the liquid-layer width. The form of this disjoinging potential was found to be exponential and monotonically decreased as width increased for high angles and produced an attractive minimum for low angles. The results of this work were compared to a pure material from a previous study.

abstract: Master of Applied Science (MASc)


title: “TALK TO ME:” A MIXED METHODS STUDY ON SERIOUSLY ILL PATIENTS’ VIEWS ON PHYSICIAN BEHAVIOURS DURING ADVANCE CARE PLANNING AND END-OF-LIFE COMMUNICATION

contributor:
You, John
Sherifali, Diana
Brazil, Kevin
Health Research Methodology

subject:
advance care planning
end-of-life communication
mixed methods
patient-physician relations
Critical Care
Oncology
Other Medical Specialties
Primary Care
Critical Care

abstract:
Background: The objective of this mixed methods study is to understand, from the perspectives of seriously ill hospitalized patients, the effect of modifiable physician behaviours on the perceived quality of end-of-life and ACP communication.

Methods: A convergent parallel mixed methods design is used. Participants were recruited from inpatient medical wards at two academic hospitals, and a population with a high risk of mortality at 6-12 months was selected. In the quantitative strand, a questionnaire was administered to measure patients’ self-rated satisfaction with their physician’s ACP communication skills. The primary analysis involved calculation of the strength of correlation between individual QOC items and a global satisfaction score. In the qualitative strand, interpretive description methods were used to explore seriously ill patients’ perceptions of the quality of ACP communication with their physicians. The mixed methods analysis phase involved the creation of a merged analysis table.

Results: From the quantitative strand, three priority behaviours pertained to eye contact, providing full attention, and listening. The three major qualitative themes related to nonverbal behaviours; situating a patient in the context of their background, family and social roles; and assisting patients to make the challenging end-of-life transition. The merged analysis allowed for a fuller, contextualized understanding of why the QOC items with the strongest correlation measures were important from a patient perspective.

Conclusions: This mixed methods study is well-positioned to understand, holistically and from the patient perspective, physician behaviours that influence quality of communication at the end of life.

abstract: Master of Science (MSc)


title: CHARACTERIZATION OF THE OLIGOMERIZATION OF THE HUMAN XRCC4 DNA REPAIR PROTEIN: IMPLICATIONS TO NON-HOMOLOGOUS END JOINING

contributor:
Junop, Murray
Cecile Fradin, Xu-Dong Zhu
Biochemistry

subject:
XRCC4
XLF
NHEJ
DNA repair
Biochemistry
Biochemistry

abstract: If not efficiently repaired, DNA double-stranded breaks can result in cell death. A major contributor to the repair of this DNA damage is the non-homologous end joining pathway (NHEJ) which depends on the proteins: X-ray cross complementing protein 4 (XRCC4) and XLF. These proteins form a complex that can bridge DNA substrates in vitro. Analysis of these proteins has demonstrated that the C-terminal region of XRCC4 is necessary for this bridging function. However, this region is also critical for both tetramerization and DNA binding abilities of XRCC4, making the interpretation of XRCC4's role in the DNA-bridging unclear. Here, we intend to further characterize the tetramerization of XRCC4 and find a functionally independent mutant. Our studies suggest that regions in the N-terminus of XRCC4 may be important for the tetramerization of the protein but not for its DNA binding ability. These mutants were also analyzed by circular dichroism and mobility shift assays to verify for the integrity of their secondary structure composition and show that they are able to interact with its known binding partner, DNA Ligase IV. Additionally, we have shown that the XRCC4:XLF complex as well as XLF alone are able to interact with DNA substrates as short as 36 base pairs. Taking the data together, we expect to be able to construct a structural model for the XRCC4:XLF complex with DNA and obtain a better understanding on the role of XRCC4’s tetramerization in the NHEJ pathway. As deficiency of XRCC4 has been implicated with tumourigenesis and immunodeficiency, understanding its role will be helpful for the development of treatments for such complications.

abstract: Master of Science (MSc)


title: Study of Luminescent Silicon-Rich Silicon Nitride and Cerium and Terbium Doped Silicon Oxide Thin Films

contributor:
Mascher, Peter
Engineering Physics

subject: silicon nanoclusters

subject: cerium disilicate nanocrystals

subject: X-ray absorption near edge structure

subject: X-ray excited optical luminescence

subject: X-ray diffraction

subject: Semiconductor and Optical Materials

subject: Semiconductor and Optical Materials

abstract: Silicon nanostructures formed in silicon-rich silicon nitride (SRSN) and cerium and terbium doped silicon oxide thin films grown using different types of plasma-enhanced chemical vapour deposition have been studied through photoluminescence (PL) and synchrotron-based X-ray absorption spectroscopies to determine the effects of deposition and processing parameters on the luminescent and structural properties of these materials. The SRSN films exhibited bright PL attributed to quantum confinement effects in the silicon nanoclusters (Si-ncs) as well as radiative defects in the silicon nitride host matrix. The peak emission energy could be tuned from the near-infrared across the entire visible spectrum by controlling the film composition and the post-deposition annealing temperature and time to change the size of the Si-ncs. Preliminary experiments on cerium doped SRSN samples indicated that although the cerium ions coordinate in the optically active trivalent oxidation state, they were not effectively sensitized by Si-ncs in the films tested, most likely due to the nanoclusters having bandgap energies that were unsuitable for this purpose. In cerium and terbium co-doped silicon oxide films, cerium disilicate (Ce2Si2O7) nanocrystallites were formed by annealing at temperatures of 900°C and higher. The A-Ce2Si2O7, G-Ce2Si2O7, and Ce6[Si4O13][SiO4]2 phases of cerium disilicate were observed to form under different deposition and annealing conditions. All three phases exhibited extremely bright violet-blue PL and were found to efficiently sensitize green emission from co-dopant Tb3+ ions in the films. The Tb3+ luminescence predominantly corresponded to the 5D4→7F3–6 emission lines, although weak 5D3→7F2–6 emission lines were also observed in films containing relatively high concentrations of terbium indicating that the sensitization of Tb3+ ions occurred through the 5D3, 5L10, or 5D2 energy levels.

abstract: Doctor of Philosophy (PhD)


title: Noetherian Prime Rings of Krull Dimension One

contributor:
Mueller, B.J.
Mathematics

subject: Mathematics Mathematics

abstract:
A right noetherian prime ring R is, by Goldie's Theorem, a right order in a simple artinian ring Q: Q is obtained from R by inverting all non-zero-divisors. O can be described as the quotient ring of R at a torsion theory, the Goldie torsion theory. If R has right Krull dimension one, the Goldie torsion theory is generated by the class of all simple right R-modules.

In this thesis we develop a theory of localization for (right) noetherian prime rings of (right) Krull dimension one, based on the direct decompositions of the Goldie torsion theory. We characterize these decompositions, using a natural partition of the class of all simple modules, and show that the quotient rings at the components remain right noetherian, prime and of right Krull dimension one. Other desirable properties of these localizations are determined: they are perfect, they preserve the two-sidedness of ideals, and they are well behaved on the simple modules. We further show that they generalize the localizations at classical semiprime ideals.

A criterion is given for a right quotient ring at a component of a decomposition of the right Goldie torsion theory to be also a left quotient ring at a component of the left Goldie torsion theory. We show that this criterion is satisfied if the ring has global dimension no longer than two.

Finally, we study hereditary noetherian prime rings in the context of our localization theory.

abstract: Doctor of Philosophy (PhD)


title: Early Adversity and Mental Health Outcomes: Linking Extremely Low Birth Weight, Neuroendocrine Dysregulation, and Internalizing Behaviours

contributor:
Schmidt, Louis A.
Mel Rutherford, Dr. Geoff Hall
Psychology

subject:
anxiety
depression
extremely low birth weight
HPA axis
internalizing problems
stress reactivity
Developmental Psychology
Health Psychology
Psychology
Developmental Psychology

abstract: Salivary cortisol and electrocardiogram data was collected at baseline and after a stress-anticipation task in extremely low birth weight (ELBW; < 1000 grams) survivors and normal birth weight (NBW) controls, in order to examine the moderating influence of emotion regulation on the relationship between being born at ELBW and internalizing problems in adulthood. The stress manipulation was an adapted Trier Social Stress Task. The participants were told they would have three minutes to create a speech on one of three predetermined topics (i.e., gun control, same sex marriage, or abortion). After three minutes passed, the particpants were told that there would be no speech. All participants showed a decrease in salivary cortisol levels throughout the day, and an increase in heart rate during the stress anticipation task. When a median split was used to create high and low stress reactive cortisol and heart rate groups, an interaction was found between birth status (ELBW vs. NBW) and group (High vs. Low Stress Reactive Cortisol) on self-reported internalizing problems (anxiety, depression, withdrawal). Those born at ELBW who had high stress reactive cortisol self-reported significantly higher levels of internalizing problems compared to ELBWs with low stress reactive cortisol. Those born at NBW did not differ on self-reported internalizing problems based on their stress reactive cortisol levels. When the moderating effect was probed with a linear regression analysis, the ELBW group was driving the relation between stress reactive cortisol levels and internalizing problems. Taken together, the results suggest that emotion regulation, as indexed by the neuroendocrine system, is moderating the relation between being born at ELBW and internalizing problems in adulthood. This is indicative of a differential susceptibility of risk and resilency in ELBW survivors depending on their ability to regulate their emotions, specifically during periods of stress.

abstract: Master of Science (MSc)


title: EXPERIEMENTAL INVESTIGATION OF POOL BOILING AND BOILING UNDER SUBMERGED IMPINGING JET OF NANOFLUIDS

contributor:
Hamed, M.S.
Mechanical Engineering

subject:
Pool Boiling
Nanofluids
Surface roughness
Submerged Impingement jet
Heat Transfer, Combustion
Other Mechanical Engineering
Heat Transfer, Combustion

abstract:
An experimental investigation has been carried out in order to investigate the effect of surface initial conditions, concentration, nanoparticles size and deposition pattern on pool boiling and jet impingement boiling of nanofluids. A flat copper surface with initial conditions of Ra = 420 nm, Ra = 80 nm and Ra = 20 nm has been used as the boiling surface. Al2O3 and CuO nanoparticles have been used with de-ionized water to prepare the nanofluids. At 0.01 vol. % concentration of Al2O3, the rate of heat transfer enhanced by 41% and 34% for the Ra = 80 nm and Ra = 20 nm, respectively. While, in the case of Ra = 420 nm, the rate of heat transfer deteriorated by 49%. At 0.005 vol. % concentration the rate of heat transfer deteriorated for all three surfaces. It is believed that the deterioration was due to the uniformity of the deposition. Using 0.01 vol. % concentration of CuO nanofluids resulted in the same trend, however, the rate of heat transfer is less compared to using Al2O3 nanofluids. For example, in the case of Ra = 80 nm, the rate of heat transfer was reduced by 14%.

The effect of nanoparticles size has been investigated by changing the nanoparticles size from 50 nm to 10 nm. The change in nanoparticles size resulted in a significant deterioration in the rate of heat transfer for all three surfaces. It is believed that the deterioration was due to the deposition uniformity. As the deposition uniformity has been found to be a major factor that affects the rate of heat transfer, new approach was introduced to quantify the effect of the rate of deposition on the pool boiling of nanofluids.

An experimental investigation has been carried out in order to investigate using submerged impingement jet on the rate of heat transfer using nanofluids. At of 0.005 vol. % concentration of Al2O3, surface with Ra = 80 nm, jet to surface vertical distance of 3 mm and Reynolds number of 101311, the rate of heat transfer deteriorated by 19%.

Comparing the pool boiling and jet impingement boiling of nanofluids showed that, in the case of jet impingement boiling, the rate of heat transfer was enhanced compared to the case of pool boiling and the deposition was less. However, jet impingement boiling experiments showed deterioration in the rate of heat transfer by 19% compared with pure water.

abstract: Master of Applied Science (MASc)


title: Weighted Feature Classification

contributor:
Janicki, Ryszard
Qiao, S.
Computer Science

subject:
Classification
Artificial Intelligence
Support Vector Machines
Pairwise Comparison
Inconsistency
Other Computer Engineering
Other Computer Engineering

abstract:
Most existing classification algorithms either consider all features as equally important (equal weights), or do not analyze consistency of weights assigned to features. When features are not equally important, assigning consistent weights is a not obvious task. In general we have two cases. The first case assumes that a given sample of data does not contain any clue about the importance of features, so the weights are provided by a pool of experts and they are usually inconsistent. The second case assumes that the given sample contains some information about features importance, hence we can derive the weights directly from the sample. In this thesis we deal with both cases. Pairwise Comparisons and Weighted Support Vector Machines are used for the first case. For the second case a new approach based on the observation that the feature importance could be determined by the discrimination power of features has been proposed. For the first case, we start with pairwise comparisons to rank the importance of features, then we use distance-based inconsistency reduction to refine the weights assessment and make comparisons more precise. As the next step we calculate the weights through the fully-consistent or almost consistent pairwise comparison tables. For the second case, a novel concept of feature domain overlappings has been introduced. It can measure the feature discrimination power. This model is based on the assumption that less overlapping means more discrimination ability, and produces weights characterizing the importance of particular features. For both cases Weighted Support Vector Machines are used to classify the data. Both methods have been tested using two benchmark data sets, Iris and Vertebal.

The results were especially superior to those obtained without weights.

abstract: Master of Computer Science (MCS)


title: Spectroscopy and Photometry of Scattered Light Echoes from Supernovae

contributor:
Welch, Douglas L.
Sutherland, Peter G.
Physics and Astronomy

subject: light echo

subject: supernovae

subject: SN 1987A

subject: Cas A

subject: time-domain astronomy

subject: Stars, Interstellar Medium and the Galaxy

abstract:
We present an observational protocol to observe and interpret asymmetries in stellar explosions using scattered light echoes. Spectroscopy of multiple light echoes are used to observe single astronomical sources from multiple viewing angles, allowing for direct observations of explosion asymmetries, when they exist. We present asymmetry detections for two famous historical supernovae: the ~25-year-old SN 1987A and the ~330-year-old Cassiopeia A. In both supernovae we find asymmetries in the first few hundred days of the explosion that appear to be correlated with the geometry of Fe-rich material in the remnant states.

Spectroscopy of SN 1987A light echoes reveals a variation in the Hα line profile as a function of echo azimuth, with maximum asymmetry at position angles 16◦ and 186◦, in agreement with the major-axis of the elongated remnant ejecta. We interpret our asymmetry detection as evidence for a two-sided distribution of high-velocity 56Ni in the first few hundred days of SN 1987A, with the most dominant asymmetry redshifted in the south. For Cassiopeia A, we find evidence for a ~4000 km/s velocity excess in the first hundred days of the explosion, roughly aligned with an Fe-rich outflow in the supernova remnant and approximately opposite in direction to the motion of the compact object.

Core-collapse supernovae have not yet been successfully modelled despite decades of progress in input physics and computing capability. Despite the significance of thermonuclear Type Ia supernovae to cosmology, the progenitor systems and explosion details also remain unclear. Both observational and theoretical work suggest that non-spherical effects are not only common in supernovae, but may in fact aid in generating successful explosions. In addition to offering a new technique for observing supernova asymmetries, spectroscopy of scattered light echoes allows a direct causal connection to be made between stellar explosions and their observed remnant states.

abstract: Doctor of Philosophy (PhD)


title: MODELING, DESIGN, AND ADJOINT SENSITIVITY ANALYSIS OF NANO-PLASMONIC STRUCTURES

contributor:
Bakr, Mohamed H.
Li, Xun
Electrical and Computer Engineering

subject:
NanoPlasmonics
Photonics
Adjoint Variable Method
Transmission Line Modeling
Terahertz Spectroscopy
Dispersive Models
Convex Optimization
Coupled Microcavities
Metamaterials
Dielectric Resonator Antenna
Electrical and Electronics
Electromagnetics and photonics
Engineering Physics
Optics
Semiconductor and Optical Materials
Electrical and Electronics

abstract: The thesis intends to explain in full detail the developed techniques and approaches for the modeling, design, and sensitivity analysis of nano-plasmoic structures. However, some examples are included for audiences of general microwave background. Although the thesis is mainly focused on simulation-based techniques, analytical and convex optimization approaches are also demonstrated. The thesis is organized into two parts. Part 1 includes Chapters 2-4, which cover the simulation-based modeling and sensitivity analysis approaches and their applications. Part 2 includes Chapters 5 and 6, which cover the analytical optimization approaches.

abstract:
We propose novel techniques for modeling, adjoint sensitivity analysis, and optimization of photonic and nano-plasmonic devices. The scope of our work is generalized to cover microwave, terahertz and optical regimes. It contains original approaches developed for different categories of materials including dispersive and plasmonic materials. Artificial materials (metamaterials) are also investigated and modeled. The modeling technique exploits the time-domain transmission line modeling (TD-TLM) technique. Generalized adjoint variable method (AVM) techniques are developed for sensitivity analysis of the modeled devices. Although TLM-based, they can be generalized to other time-domain modeling techniques like finite difference time-domain method (FDTD) and time-domain finite element method (FEM).

We propose to extend the application of TLM-based AVM to photonic devices. We develop memory efficient approaches that overcome the limitation of excessive memory requirement in TLM-based AVM. A memory reduction of 90% can be achieved without loss of accuracy and at a more efficient calculation procedure. The developed technique is applied to slot waveguide Bragg gratings and a challenging dielectric resonator antenna problem.

We also introduce a novel sensitivity analysis approach for materials with dispersive constitutive parameters. To our knowledge, this is the first wide-band AVM approach that takes into consideration the dependence of material properties on the frequency. The approach can be utilized for design optimization of innovative nano-plasmonic structures. The design of engineered metamaterial is systematic and efficient. Beside working with engineered new designs, dispersive AVM can be utilized in bio-imaging applications. The sensitivity of the objective function with respect to dispersive material properties enables the exploitation of parameter and gradient based optimization for imaging in the terahertz and optical regimes. Material resonance interaction can be easily investigated by the provided sensitivity information.

In addition to the developed techniques for simulation-based optimization, several analytical optimization algorithms are proposed to foster the parameter extraction and design optimization in terahertz and optical regimes. In terahertz time-domain spectroscopy, we have developed an efficient parameter based approach that utilizes the pre-known information about the material. The algorithm allows for the estimation of the optical properties of sample materials of unknown thicknesses. The approach has been developed based on physical analytical dispersive models. It has been applied with the Debye, Lorentz, Cole-Cole, and Drude model.

Furthermore, we propose various algorithms for design optimization of coupled resonators. The proposed algorithms are utilized to transform a highly non-linear optimization problem into a linear one. They exploit an approximate transfer function of the coupled resonators that avoids negligible multiple reflections among them. The algorithms are successful for the optimization of very large-scale coupled microcavities (150 coupled ring resonators).

abstract: Doctor of Philosophy (PhD)


title: Development of a Microchip-Based Flow Cytometer with Integrated Optics – Device Design, Fabrication, and Testing

contributor:
Chang-Qing Xu/Zhiyi Zhang
Fang, Qiyin
Selvaganapathy, Ravi
Engineering Physics

subject:
Microfluidic
flow cytometry
integrated optics
optofluidics
fluorescence and scatter detection
Biomedical devices and instrumentation
Biomedical devices and instrumentation

abstract: Lab-on-a-chip technologies have created a burgeoning number of new and novel devices designed to automate biological processes on-chip in an efficient and inexpensive format for far reaching point-of-care (POC) medicine and diagnostic treatments and for remote and on-line monitoring functions. This work designed a device that integrated advanced optical functionality on-chip with the microfluidics to relieve the reliance on traditional bulky and expensive free-space optics and a high-quality light source. The multimodal input beam was reshaped into an optimized geometry in the microchannel via a 2D system of lenses - improving the quality and reliability of detection through uniform detection of particles. A uniform beam geometry across the sample stream with a uniform beam width will allow repeatable excitation and burst duration to allow for more reliable and predictable detection. Numerous beam geometries were created and the quality and illumination properties confirmed by testing each with a couple sizes of fluorescent and non-fluorescent microspheres to test the effect of beam geometry and particle size combination on device performance. The measured coefficient of variation (CV) for fluorescent beads was found to have a particular beam geometry that yielded best device performance based on the bead size. Fluorescent beads 2.5µm in diameter had a CV of 8.5% for a 3.6 µm beam waist while 6 µm beads yielded a 14.6% CV with a 10 µm beam waist. When measuring scatter and fluorescence signal from a 10 µm the 2.5- and 6.0 µm beads gave 11.4% and 15.8% and 15.9% and 20.4% fluorescent and scatter CVs for each set of beads, respectively. Separately testing each beam geometry with 1-, 2-, and 5 µm beads did not yield any predictable ideal beam-bead ideal pairing for best performance. Lastly, further integration of optical function was shown through the on-chip collection of signals; CVs of 29% and 30% were measured for side scatter and forward scatter, respectively, for 5 µm beads. The reliability of this all-optically guided scheme was confirmed by comparing it to a simultaneously recorded free-space collection scheme. The coincidence rate was found to be 94% and 96% for the side scatter and forward scatter schemes. Both had very low false positive rates – below 0.5% - with missed detection rates that were satisfactory but in need of improvement. Sources of noise and device improvements were identified and suggested.

abstract: Doctor of Philosophy (PhD)


title: EFFECT OF UPSTREAM EDGE GEOMETRY ON THE TRAPPED MODE RESONANCE OF DUCTED CAVITIES

contributor: Marilyn F. Lightstone and James S. Cotton

subject:
Internal axisymmetric cavity
trapped modes
passive suppression
cavity flow
acoustic resonance
Acoustics, Dynamics, and Controls
Engineering
Mechanical Engineering
Acoustics, Dynamics, and Controls

abstract: This thesis investigates the effect of different passive suppression techniques of different configurations on the flow-excited acoustic resonance of an internal axisymmetric cavity. This type of acoustic resonance is observed in many practical applications such as valves installed in steam pipe lines, and gas transport system. An experimental setup of a cavity-duct system has been altered to facilitate the study of the suppression and/or delay of resonance over the range of Mach number of 0.07-0.4. Three different cavity depths have been studied d=12.5 mm, 25 mm, and 50 mm deep. For each depth, the cavity length is changed from L=25 mm to 50 mm. The investigation matrix includes the study of two rounding radii, two chamfer geometries and three different types of spoilers, all located at the leading edge of the cavity. A reference case of no suppression seat installed for each of the examined cavity geometries is tested. Rounding off cavity edges for both radii has increased the acoustic pressure level, yet delayed the onset of resonance. Chamfering the upstream edge of the cavity delayed the onset of resonance as a result of increasing the cavity characteristic length which delays the coupling of the shear layer perturbations and the acoustic field. The delay and the suppression of resonance achieved by the chamfer depend on the size of the cavity. All spoiler configurations have proven effectiveness in delaying and suppressing resonance for all cavities. The choice of spoiler configuration would depend on cavity size and robustness/strength of acoustic resonance.

abstract: Master of Science (MSc)


title: The Heritage of Life and Death in Historical Family Cemeteries of Niagara, Ontario

contributor:
Cannon, Aubrey
Ellen Badone and Ann Herring
Anthropology

subject:
Historical archaeology
family cemeteries
Ontario heritage
commemoration
Niagara
Archaeological Anthropology
Archaeological Anthropology

abstract:
This study explores the history of Niagara settlement and settlers through the changing patterns of burial and commemoration visible in historical family cemeteries established following Euro-American settlement in the 1790s. Data collected from a combination of site survey and archival research demonstrate three clear phases of: 1) early cemetery creation and use 2) the transition to burial in public cemeteries throughout the late 1800s; and 3) the closure of family cemeteries by the early 1900s followed by periods of neglect and renewal characterized by inactive cemeteries being repurposed by descendants as sites of heritage display.

There is incredible variation in burial data and the overall patterns speak to changing identity relating to family, land, community, memory, and history. More specifically, the results of this study demonstrate a shift from an identity created through the experience of family place and burial to a community-based identity that emphasizes the nuclear family and their history within their wider social network. More recent heritage displays have explicitly introduced a narrative of settlement, Loyalist identity, and land ownership that was inherent when cemeteries were in use.

This cemetery-based history approach demonstrates the potential of mortuary material culture to address questions of social change within the historical context in which it was created and used. It also highlights the value of variability in cemetery data and the consideration of the circumstances of cemetery creation, use, neglect, and renewal to inform the range of personal and collective histories that are visible over generations.

abstract: Doctor of Philosophy (PhD)


title: Volunteerism in Context: A Comparison on Habitat for Humanity Canada Programs

contributor:
Fetner, Tina
Gillett, James
Heath, Melanie
Sociology

subject:
Volunteerism
Voluntourism
Motivation
Class Identity
Social Networking
Social Change
Community Engagement
Inequality and Stratification
Leisure Studies
Tourism
Community Engagement

abstract:
This thesis applies a Bourdieuian analysis to a qualitative study of volunteerism that focuses on the question of how ‘doing good’ relates to social change overall? - in particular, the ways that social class influences the volunteer experience and the overall culture of volunteerism. I argue that the leading theoretical research models of volunteerism need to recognize the evolving nature of the activity and theorize the influences that are structuring the culture of volunteerism. What emerges is a model of volunteering where motivation is understood as a complex set of factors that are structured by social class identities and volunteering is understood as a form of distinction that can be used to acquire cultural capital. Social class-based ideas, in particular, the values related to the middle class, have become a part of the culture of volunteerism and, in part, create and reproduce the social change/volunteerism paradox. The volunteerism/social change paradox is the idea that volunteerism is often perceived as a social change activity when in many cases it reproduced the status quo. Without a strong activism component to the volunteerism, it is not an inequality challenging activity.

This thesis presents interview and observation data collected with Habitat for Humanity Canada in their two largest programs – the National program (domestic) and the Global Village program (international). By utilizing ideas of class, class distinction and social and cultural capital from Bourdieu’s work, the role of class, the culture of benevolence (or volunteerism) can be explored in a new way. What emerges is a culture of volunteerism that is deeply influenced by middle class values where social change ideas are common but structural change is not – resulting in the volunteer/social change paradox.

abstract: Doctor of Philosophy (PhD)


title: Linear Robust Control in Indirect Deformable Object Manipulation

contributor:
Patriciu, Alexandru
Electrical and Computer Engineering

subject:
Medical Robotics
Robot Control
Deformable Object Manipulation
Robust Control
Controls and Control Theory
Controls and Control Theory

abstract: Robotic platforms have several characteristics such as speed and precision that make them enticing for use in medical procedures. Companies such as Intuitive Medical and Titan Medical have taken advantage of these features to introduce surgical robots for minimally invasive procedures. Such robots aim to reduce procedure and patient recovery times. Current technology requires platforms to be master-slave manipulators controlled by a surgeon, effectively converting the robot into an expensive surgical tool. Research into the interaction between robotic platforms and deformable objects such as human tissue is necessary in the development of autonomous and semi-autonomous surgical systems. This thesis investigates a class of robust linear controllers based on a worst case performance measure known as the $H_{\infty}$ norm, for the purpose of performing so called Indirect Deformable Object Manipulation (IDOM). This task allows positional regulation of regions of interest in a deformable object without directly interacting with them, enabling tasks such as stabilization of tumors during biopsies or automatic suturing. A complete approach to generating linear $H_{\infty}$ based controllers is presented, from derivation of a plant model to the actual synthesis of the controller. The introduction of model uncertainty requires $\mu$ synthesis techniques, which extend $H_{\infty}$ designs to produce highly robust controller solutions. In addition to $H_{\infty}$ and $\mu$ synthesis designs, the thesis presents an approach to design an optimal PID controller with gains that minimize the $H_{\infty}$ norm of a weighted plant. The three control approaches are simulated performing set point regulation in $\text{MATLAB}^{TM}$'s $simulink$. Simulations included disturbance inputs and noises to test stability and robustness of the approaches. $H_{\infty}$ controllers had the best robust performance of the controllers simulated, although all controllers simulated were stable. The $H_{\infty}$ and PID controllers were validated in an experimental setting, with experiments performed on two different deformable synthetic materials. It was found that $H_{\infty}$ techniques were highly robust and provided good tracking performance for a material that behaved in a relatively elastic manner, but failed to track well when applied to a highly nonlinear rubber compound. PID based control was outperformed by $H_{\infty}$ control in experiments performed on the elastic material, but proved to be superior when faced with the nonlinear material. These experimental findings are discussed and a linear $H_{\infty}$ control design approach is proposed.

abstract: Master of Applied Science (MASc)


title: Parity Measurements Using the Polarized (d, α) Reaction Near 0º

contributor:
Kuehner, John A.
Physics

subject: Physics Physics

abstract:
A new model-independent method is presented for determining certain spectroscopic information in odd-odd nuclei. It uses the (d, α) reaction with a polarized deuteron beam incident on a spin-zero target nucleus and with the alpha particles detected near 0º to the beam direction. By measuring the tensor analyzing power for the reaction to a particular final state, it is possible to determine whether that state has natural parity or unnatural parity. In addition, the method allows spin-zero levels in the final nucleus to be uniquely identified and the tensor polarization of the beam to be measured. The fluctuations of the tensor analyzing power with energy for unnatural parity states are calculated using the statistical compound nucleus model and it is shown that, for most cases, an average of the cross-sections for three energies will be sufficient for unambiguously assigning natural parity or 0‾ to a level. It has also been shown that the expected attenuation of the tensor analyzing power for natural parity states is negligible when the alpha particles are detected near 0º.

This method is applied to the reactions 12C(d,α)10B, 16O(d,α)14N, and 40Ca(d,α)38K, resulting in many new spin and parity assignments. In particular, assignments of J^π = 0‾ are made to the 4.91 MeV level and to one member of the doublet at 9.13 MeV in 14N. Assignments of 3‾, (2,4)‾, 2‾, (2‾,3+), 2‾, 1+, and 1+ are made to the 2613, 2647, 2870, 3317, 3815, 3857, and 3978 keV states, respectively, of 38K.

The results of a shell-model calculation of the negative parity T = 0 states in 38K are presented.

abstract: Doctor of Philosophy (PhD)


title: Diffusion and Domains: Membrane Structure and Dynamics Studied by Neutron Scattering

contributor:
Rheinstadter, Maikel
Cecile Fradin, Bruce Gaulin
Physics and Astronomy

subject:
membrane
lipid diffusion
lipid domains
neutron scattering
lipid bilayer
cholesterol
Biological and Chemical Physics
Biological and Chemical Physics

abstract:
Biological membranes play host to a number of processes essential for cellular function and are the most important biological interface. The structurally complex and highly dynamic nature of the membrane poses significant measurement challenges, requiring an experimental technique capable of accessing very short, nanometer length scales, and fast, micro-pico second time scales.

The experimental work presented in this thesis uses a variety of neutron scattering techniques to study the structure and dynamics of biologically relevant model membrane systems. The main body of this work can be sub-divided into two distinct topics: (1) lateral diffusion of lipid molecules in a bilayer; and (2) the measurement of domains in the membrane.

Diffusion is the fundamental mechanism for lipids and proteins to move throughout the lipid matrix of a biological membrane. Despite a strong effort to model lipid diffusion, there is still no coherent model which describes the motion of lipid molecules from less than a lipid-lipid distance to macroscopic length scales. The experiments presented on this topic attempt to extend the range over which diffusion is typically measured by neutron scattering, to initiate the development of a more complete lipid diffusion model.

Lipid domains and rafts are thought be platforms for many cellular functions; however, their small size and transient nature makes them notoriously difficult to observe. The penultimate chapter of this thesis provides evidence supporting the existence of domains in a model lipid/cholesterol system by probing of the dynamics of the system. The challenge of observing these structures directly was addressed by modifying the traditional neutron triple-axis spectrometry setup to increase its sensitivity to systems with short-range order. This technique was employed to examine the coexistence of fluid and gel domains in a single-component lipid bilayer system, as well as the presence of highly ordered lipid domains in a model membrane containing cholesterol.

abstract: Doctor of Philosophy (PhD)


title: Development of Applicable Benchmark Experiments for (Th,Pu)O2 Power Reactor Designs Using TSUNAMI Analysis

contributor:
Buijs, A.
Engineering Physics

subject:
(Th
Pu)O2
TSUNAMI
Sensitivity and Uncertainty
Nuclear
CANDU
Nuclear Engineering
Nuclear Engineering

abstract: When simulating reactor physics experiments, uncertainties in nuclear data result in a bias between simulated and experimental values. For new reactor designs or for power reactor designs the bias can be estimated using a set of experiments. How- ever, the experiments used to estimate the bias must be applicable to the power reactor design of interest. Similarity studies can be performed to ensure this is the case. Here, potential experiments in the ZED-2 heavy water critical facility at Chalk River Laboratories were developed that would be applicable to the multiplication factor bias calculation of three thoria plutonia fuelled power reactor designs. The power reactor designs that were analyzed were the CANDU 6 with 37-element fuel bundles and 43-element fuel bundles, and a Canadian SCWR design with 78- element fuel assemblies. The power reactors were simulated using the code package SCALE 6.1 under burnup conditions that were determined using the lattice code DRAGON 3.06H and the diffusion code DONJON 3.02A. The intermediate results from DRAGON and DONJON were used to compare the benefits of various reactor designs. Various critical core conﬁgurations were then simulated in the ZED-2 re- actor using the SCALE 6.1 package. The similarities between the potential ZED-2 reactor experiments and the power reactors were analyzed. These results were used to design a set of experiments having sufficiently high completeness that they can be used as part of a bias calculation using the generalized linear least squares method. To do so a methodology was developed to guide the experiment set design process in which the fuel type, lattice arrangements, and coolant type are modiﬁed and the eﬀects on the sensitivity coverage analyzed. A set of six experiments was designed for which all of the power reactor designs had a completeness of 0.7 or higher.

abstract: Master of Applied Science (MASc)


title: CMOS IMAGE SENSORS WITH COMPRESSIVE SENSING ACQUISITION

contributor:
Shirani, Shahram
Deen, Jamal M.
Nicolici, Nicola
Electrical and Computer Engineering

subject: CMOS image sensors

subject: Compressive sensing

subject: CS-CMOS imager

subject: Hardware implementation

subject: Block read-out

subject: Multiple camera

subject: Electrical and Electronics

subject: Electronic Devices and Semiconductor Manufacturing

subject: Signal Processing

subject: VLSI and circuits, Embedded and Hardware Systems

subject: Electrical and Electronics

abstract:
The compressive sensing (CS) paradigm provides an efficient image acquisition technique through simultaneous sensing and compression. Since the imaging philosophy in CS imagers is different from conventional imaging systems, new physical structures are required to design cameras suitable for CS imaging.

While this work is focused on the hardware implementation of CS encoding for CMOS sensors, the image reconstruction problem of CS is also studied. The energy compaction properties of the image in different domains are exploited to modify conventional reconstruction problems. Experimental results show that the modified methods outperform the 1-norm and TV (total variation) reconstruction algorithms by up to 2.5dB in PSNR.

Also, we have designed, fabricated and measured the performance of two real-time and area-efficient implementations of the CS encoding for CMOS imagers. In the first implementation, the idea of active pixel sensor (APS) with an integrator and in-pixel current switches are used to develop a compact, current-mode implementation of CS encoding in analog domain. In another implementation, the conventional three-transistor APS structure and switched capacitor (SC) circuits are exploited to develop the analog, voltage-mode implementation of the CS encoding. With the analog and block-based implementation, the sensing and encoding are performed in the same time interval, thus making a real-time encoding process. The proposed structures are designed and fabricated in 130nm technology. The experimental results confirm the scalability, the functionality of the block read-out, and the validity of the design in making monotonic and appropriate CS measurements.

This work also discusses the CS-CMOS sensors for high frame rate CS video coding. The method of multiple-camera with coded exposure video coding is discussed and a new pixel and array structure for hardware implementation of the method is presented.

abstract: Doctor of Philosophy (PhD)


title: Spatiotemporal gait symmetry in individuals with clinical unilateral knee osteoarthritis compared to healthy controls: A pilot study

contributor: Monica Maly, Paul Stratford, Joy MacDermid

subject:
knee
osteoarthritis
gait
symmetry
Medicine and Health Sciences
Rehabilitation and Therapy
Medicine and Health Sciences

abstract:
Purpose: This study describes gait characteristics and evaluates whether step length, step time and stance time symmetry index (SI) ratio (differences between limbs divided by the bilateral average) and variables of each limb (limb-specific) can be reliably measured in a sample of unilateral knee osteoarthritis (KOA) and healthy participants. A secondary objective estimates between- and within-group differences and correlations between SIs and limb-specific variables with measures of pain, perceived exertion and physical function over an experimental walking intervention.

Design: Observational cohort. SI and limb-specific variables test-retest reliability and differences in KOA and healthy individuals before and after the walk intervention were estimated.

Methods: Eight subjects were in each of the KOA and healthy groups. The GAITRite® captured step length, step time and stance time on three test occasions. Test-retest reliability was measured over two administrations. Pain (Numeric Pain Rating Scale) and perceived exertion (Borg Rating of Perceived Exertion) were collected before and after each test. The six-minute and treadmill walk tests comprised the experimental walking intervention. Point and interval estimates of SIs and limb-specific variables before and after the walk intervention for test-retest reliability, between- and within-group differences as well as Pearson correlations were obtained.

Results: Limb-specific variables showed better test-retest reliability (ICC 0.94 to 0.97) than SIs (ICC 0.77 to 0.87). Differences were observed in both groups’ perceived exertion rating (KOA -7.4 (-8.5 to -6.4); Healthy -6.7 (-8.0 to -5.5)) over the experimental walking intervention. In the KOA group, high correlations (r = 0.75 to 0.93) were observed between pain and both step and stance times as well as physical function and step length, varying in magnitude and direction depending on which limb was supporting.

Conclusion: The findings suggest that limb-specific measures are reliable and useful as biomechanical indices of compensatory KOA gait, correlating with pain and physical function.

abstract: Master of Science (MSc)


title: A Study of the Mechanical Properties of Silicon-Based Thin Films Deposited by ECR-PECVD and ICP-CVD

contributor:
Mascher, Peter
Turak, Ayse
Engineering Physics

subject:
Silicon
Hardness
Modulus
Film
Nanoindentation
PECVD
Nanoscience and Nanotechnology
Nanoscience and Nanotechnology

abstract:
Silicon-based dielectric thin films including amorphous hydrogenated aluminium-doped silicon oxides (a-SiAlxOy:H), amorphous hydrogenated silicon nitrides (a-SiNx:H), and amorphous hydrogenated silicon carbides (a-SiCx:H) were deposited by remote plasma chemical vapour deposition (RPECVD) techniques including electron cyclotron resonance plasma enhanced chemical vapour deposition (ECR-PECVD) and inductively-coupled-plasma chemical vapour deposition (ICP-CVD) on silicon (Si) wafers, soda-lime glass microscope slides, and glassy carbon (C) plates. Aluminium (Al) in the SiAlO films was incorporated by way of a metalorganic Al(TMHD)3 precursor.

Thickness, refractive index, and growth rate of the films were measured using variable angle spectroscopic ellipsometry (VASE). Film composition was measured using energy dispersive X-ray spectroscopy (EDX) for the SiAlO films and Rutherford backscattering spectrometry (RBS) for the SiCx films. Elastic modulus and hardness of the SiAlO and SiCx films were measured using nanoindentation and their adhesion was characterized via progressive load scratch testing.

All films were observed to be optically transparent at near-IR and red wavelengths with many SiNx and SiCx films exhibiting significant optical absorption above 2.25eV. Modification of a previously developed deposition recipe produced doubled growth rates in SiNx and SiCx films. SiAlO films were produced with up to 1.6±0.1at% aluninium (Al) incorporation, while SiCx films with composition ranging from SiC0.25:H to SiC2:H could be produced depending on the growth gas flow ratios. SiAlO films exhibited hardness and reduced modulus (H and E) up to 8.2±0.4 and 75±2GPa, respectively; H and E for the SiCx filmsreached 11.9±0.2 and 87±3 GPa. Initially, adhesion to Si wafers was extremely poor with films delaminating at loads of 1.5±0.3N when scratched with a 3/16” alumina (Al2O3) sphere; implementation of a rigorous pre-deposition surface cleaning procedure produced films showing only cracking and no delamination up to 30N loads vs. a 200μm radius Rockwell C diamond stylus.

abstract: Master of Applied Science (MASc)


title: Management and Processing of Vibration Data

contributor:
Mohrenschildt, Martin v.
Computing and Software

subject:
Vibrating Screens
Rotational Machinery
Mining Industry
Vibration Analysis
Data Management
Software Engineering
Computational Engineering
Computational Engineering

abstract: Vibrating screens are mechanical machines used to sort granulated materials based on their particle size. Utilized in the mining industry, these machines can sort tonnes of materials per hour. In the past, McMaster University developed sensor devices that measure and transmit vibration data of these machines to a central data acquisition unit for analysis, tuning, and maintenance purposes. In this thesis, I present the development of two new software systems that are used to process, manage, and present the information gained from these measurements. The first system, the offline vibration analysis software, is used to analyze the vibration data in both time and frequency domain, and presents the measured and calculated data in textual and graphical forms. The second system, the online vibration analysis software, is used by vibrating screens manufacturers and their customers to gather and manage vibration data collected from their vibrating screens by utilizing a central storage. The development process of these systems followed an iterative and incremental approach with continuous feedback from stakeholders. It included extensive requirements gathering to define a model, in terms of data representation, that captures the business logic and practices of the industry. Furthermore, it used standard architectures such as Model View Controller (MVC) and advanced technologies such as Object Relationship Mapping (ORM) for data access to increase flexibility and maintainability. Finally, comprehensive unit testing and thorough security risks evaluation were conducted in order to ensure that these systems are secure and bug free.

abstract: Master of Applied Science (MASc)


title: Issues Related to Determining Optimal Management of Patients in Receipt of Disability Benefits

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
Disability Benefits
Optimal Management
Psychotherapy
Depression
Missing Participant Data
Lost to Follow-Up
Mental and Social Health
Rehabilitation and Therapy
Mental and Social Health

abstract: Approximately 4.2 million Canadian adults suffer from a physical or psychological disability, of whom up to 30% suffer from depression. Those receiving disability benefits versus those not receiving benefits may be at greater risk of unsatisfactory outcomes because their circumstances or psychological status may interfere with successful implementation of standard therapies. This thesis addresses the effectiveness of therapies for depression in patients receiving disability benefits, using an individual patient data meta-analysis of all published randomized controlled trials evaluating Cognitive Behavioural Therapy and a secondary analysis of an administrative database from a large, private, Canadian insurer. Additionally, this thesis addresses an important methodological issue: assessing the impact of missing participant data for continuous outcomes in systematic reviews. Missing participant data may bias results of individual trials or systematic reviews of individual trials if participants with missing data have different expected outcomes from those with available data. No methods have been proposed for investigating the extent to which missing participant data for continuous outcomes might bias the results of systematic reviews, and this dissertation addresses that gap.

abstract: Doctor of Philosophy (PhD)


title: Characterization and Comparison of Neuroplasticity Mechanisms in Rat and Human Cortex

contributor:
Murphy, Kathryn
Neuroscience

abstract:
Neuroplasticity describes the capacity and mechanisms underlying experience driven changes in function and organization of neural connections. Animal models have uncovered many mechanisms that control neuroplasticity, such as the E-I balance and structural brakes, and have identified the timing of critical periods in development when the degree of plasticity is high. Ocular dominance plasticity in visual cortex is the preeminent model for studying plasticity. Its a useful paradigm because it links from molecular mechanisms to anatomical and physiological changes, to visual perception and the human visual disorder of lazy-eye (amblyopia). Treatments for amblyopia have traditionally had poor efficacy (~50%), but recently, a number of interventions have shown they are able to re-instate ocular dominance plasticity in older rats. Little is known, however, about developmental translation of the mechanisms that control the critical period plasticity between rat and human. To address this, I conducted a series of experiments in human and rat cortices to characterize and compare development of a set of proteins involved in regulating neuroplasticity. First, I used Western blot analysis to quantify the development of Synapsin, Synaptophysin, PSD-95, and Gephyrin in rat and human cortex, compared the development of these proteins between species and determined the translation from rat to human cortical development. These studies revealed that total protein expression is comparable in rat and human visual cortex during early development, and that synaptic age is similar between species at comparable stages of visual system development. Second, I quantified development of GABAergic mechanisms in human visual cortex across the lifespan. I found complex and prolonged changes in these mechanisms that help to highlight stages of human cortical development. Third, I quantified the effects of reinstating ocular

dominance plasticity in adult rats using fluoxetine on the mechanisms known to facilitate the onset and closure of the critical period. This study showed that fluoxetine reduces the brakes on plasticity, and re-set the E-I balance. The results from my Ph.D. thesis experiments provide detailed characterization of synaptic development in human visual cortex, and a new comparison for studying humans and rat cortical development. Together my studies have found new insights about the capacity for neuroplasticity in human visual cortex, a new way to translate cortical developmental stages between species, and that re-instating plasticity in adult cortex effects both the brakes and plasticity promoting mechanisms.

abstract: Doctor of Philosophy (PhD)