title: The Role of Schizosaccharomyces Pombe SER/THR Kinase in Growth, Stress Response and Nutrient Deprivation

contributor:
Young, Paul G.
Biology

subject: Fission yeast, stress, Ssp1 Ser/Thr kinase, cell cycle

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2012-01-24 09:49:58.225

abstract:
Continuous sensation and reaction to environmental fluctuations is especially critical to the survival of unicellular organisms. Stress response mechanisms are essential for cells during the vegetative and sexual life cycles and quiescence. The Schizosaccharomyces pombe mitotic activator and stress response serine/threonine kinase Ssp1 acts independent of the major fission yeast Spc1 MAP kinase stress response cascade. Ssp1 is required at high temperatures in the presence of other stressors, ensures long-term viability in quiescent cells and allows efficient cell division in low-glucose conditions. Ssp1 is cytoplasmic but briefly localizes to the cell membrane after exposure to extracellular stress. It plays a role in actin depolymerization and is required for the change of growth polarity after cell division.
After identifying 14-3-3 proteins Rad24 and Rad25 as putative Ssp1 binding partners, we confirmed the interaction with co-immunoprecipitation. Association of Ssp1 with Rad24 diminishes after 15 minutes of hyperosmotic stress, however Rad25 binding is retained. Loss of the rad24 gene product rescues both ssp1- mitotic delay at elevated temperatures and sensitivity to 0. 6M KCl. Conversely, overexpression of rad24 exacerbates ssp1  stress sensitivity and mitotic delay. Diffuse actin polarity and spheroid morphology in rad24- cells improves in an ssp1- background. Ssp1 localization to the cell membrane is negatively regulated by Rad24.
Ssp1 does not co-localize with Arp3C (actin-related protein 3 homologue C) after osmotic stress, but instead appears to form a ring around the cell, suggesting localization to fission scars.
Ssp1 is basally phosphorylated and hyperphosphorylated after glucose deprivation. Ssp1 is shuttled in and out of the nucleus and accumulates in the nucleus in an exportin Cmr1 dependent manner.
Ssp1-GFP levels are constant in all stages of the vegetative cell cycle and Ssp1-GFP is present in both the sexual life cycle and quiescence. C-terminal and N-terminal truncation of ssp1 alters its subcellular localization. The C-terminal region is the site of hyperphosphorylation following glucose deprivation and is also necessary for membrane localization following osmotic stress.

abstract: We are preparing two data chapters to be published in scientific journals and do not wish to make the data in these chapters public until these papers are published.

abstract: PhD


title: The Effects of Digitization and Automation on Board Games for Digital Tabletops

contributor:
Graham, Nicholas
Computing

rights: This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.

subject:
Board Games
Digital Tabletops
User Study
Human-Computer Interaction
Digital Gaming

abstract: Thesis (Master, Computing) -- Queen's University, 2012-01-08 10:32:08.405

abstract: Digital tabletop computers are an ideal platform for games with the social advantages of traditional tabletop games, such as board games and card games, combined with the more streamlined and automated gameplay of video games. Implementing a board game digitally allows for aspects of the game, such as routine in-game activities, rule enforcement and game progression, to be automated. However, the effect of this automation on the players’ social experience and enjoyment is poorly understood. To explore this question, a mixed-method study was carried out in which 24 groups of participants played either the abstract strategy board game Checkers or the cooperative board game Pandemic using three different interfaces: the original physical game; a digital tabletop interface which provided minimal automation in an attempt to replicate play of the original game; and a digital tabletop interface which automated many in-game activities, enforced the rules and managed the progression of the game. The study revealed that while automation does have the potential to reduce the overhead to play the game, it can lead to player frustration in several ways. Automating routine in-game activities and game progression can lead to severe awareness deficits. Automation of rule enforcement and management of the game state can streamline gameplay, but can lead to scenarios where players would prefer more control over the game. The negative space around the active game area is important to consider for storage of digital artifacts and physical objects above the table. Finally the digitization and automation of the games did not reduce social interaction, making digital tabletops a promising platform for social games.

abstract: M.Sc.


title: Do Good Intentions Beget Good Policy? Two Steps Forward and One Step Back in the Construction of Domestic Violence in Ontario

contributor:
Snider, Laureen
Sociology

subject:
domestic violence
policy

abstract: Thesis (Ph.D, Sociology) -- Queen's University, 2012-01-09 22:24:41.971

abstract: The construction of domestic violence shifted and changed as this issue was forced from the private shadows to the public stage. This dissertation explores how government policy initiatives - Bill 117: An Act to Better Protect Victims of Domestic Violence and the Domestic Violence Action Plan (DVAP) - shaped our understanding of domestic violence as a social problem in the first decade of the twenty-first century in Ontario. Specifically, it asks whose voices were heard, whose were silenced, how domestic violence was conceptualized by various stakeholders. In order to do this I analyzed the texts of Bill 117, its debates, the DVAP, as well as fourteen in-depth interviews with anti-violence advocates in Ontario to shed light on their construction of the domestic violence problem. Then I examined who (both state and non-state actors) regarded the work as ‘successful’, flawed  or wholly ineffective. In particular, I focused on the claims and counter-claims advanced by MPPs, other government officials, feminist or other women’s group advocates and men’s or fathers’ rights group supporters and organizations. The key themes derived from the textual analysis of documents and the interviews encapsulate the key issues which formed the dominant construction of domestic violence in Ontario between 2000 and 2009: the never-ending struggles over funding, debates surrounding issues of rights and responsibilities, solutions proposed to address domestic violence, and finally the continued appearance of deserving and undeserving victims in public policy. This exploration is important because it speaks to issues of power, given that within and between these advocacy groups certain voices are privileged and silenced to varying degrees, and the outcomes of these complex processes contribute to the shaping of public policy and perceptions outside the state apparatus.

abstract: PhD


title: Changes in Patterns of Territory and Habitat Overlap in Wood-Warblers Over Evolutionary Time

contributor:
Martin, Paul R.
Biology

subject:
Dendroica
Territory Overlap
Habitat Overlap
Wood Warbler

abstract: Thesis (Master, Biology) -- Queen's University, 2012-01-09 11:32:42.032

abstract: Patterns of community assembly among organisms are highly influenced by the ecological traits and strategies of the species that make up those communities. The conservation of ancestral traits can be important in determining how closely related species partition space and habitat on a local scale. Shared ecological traits and strategies of closely related species suggest that they should overlap in space and use similar habitats. However, ecological similarity may result in fitness costs when closely related species live together. Previous work on birds suggests that close relatives avoid each other by using different habitats. I used the radiation of Dendroica wood-warblers to test these two alternative hypotheses and determine how closely related species partition space and habitat, and how patterns of spatial overlap and habitat use change over evolutionary timescales. I measured territory and habitat overlap among nine sympatric species of Dendroica, Setophaga and Mniotila to determine how time since common ancestry is related to patterns of spatial overlap and habitat use at the Queen's University Biological Station in eastern Ontario. I predicted that closely related species would separate by habitat and not overlap their territories. However, I found that the two most recently diverged species pairs overlap their territories and habitats significantly more than do pairs of more distantly divergent species. This pattern contrasts with previous studies on wood-warblers and the ecologically similar Phylloscopus leaf-warblers. These results suggest that during allopatric speciation Dendroica species do not differentiate in habitat on a local scale; rather, habitat differentiation occurs after closely related species have returned to sympatry.

abstract: M.Sc.


title: Density functional theory investigation into mechanisms of metal ion-promoted and base-promoted phosphorothioate cleavage reactions and Lanthanide ion catalysts for kinetic resolution of amino acid esters

contributor:
Brown, Robert Stanley
Mosey, Nicholas
Chemistry

subject: Catalysis Chemistry

abstract: Thesis (Ph.D, Chemistry) -- Queen's University, 2012-01-11 14:38:52.129

abstract:
Described here are chiral Ln3+ complexes of Schiff-base ligands and their use as catalysts for the kinetic resolution of the 4-nitrophenyl esters of N-Boc glutamine and phenylalanine through an enantioselective methanolysis/ethanolysis reaction. Catalysts were screened in various solvents and temperatures to optimize the selectivity value k2L/k2D or k2D/k2L. The greatest selectivity at 25°C determined was 7.1, however, reducing reaction temperature increases selectivity and after kinetic resolution at -40°C a product mixture with >99% e.e. with ~80% of the desired product remaining.
A computational method is presented for the prediction of the Brønsted parameter βeq, for a phosphorothioyl group transfer in methanol by comparing relative free energy values of starting materials and phenolate products for a series of related substrates. Direct comparison of starting material and anionic leaving group free energies results in a poor approximation of βeq, however given that the βeq value for the equilibrium of phenol and phenoxide is -1, the comparison of computed free energies of neutral starting material with neutral phenol product provides βeq approximations that are satisfactorily close to the experimentally derived values.
The detailed mechanism of base-promoted hydrolysis and methanolysis of O,Oʹ-dimethyl O-aryl phosphorothioates and phosphates was examined computationally. Generally, with increased leaving group acidity, the reactions showed a tendency toward being concerted (a single transition state) and while substrates with leaving groups with lower acidity tend to involve 5-coordinate phosphorane intermediates. Brønsted βlg values are also computed, and found to be similar to experimentally determined values.
The mechanism of palladacycle-promoted phosphorothioate methanolysis is also modeled computationally, showing a change in rate determining step from substrate binding (sspKa of leaving group phenol < 13) to leaving group departure (sspKa of leaving group phenol > 13). The calculations also predict the existence of a stable metal-bound 5-coordinate thiophosphorane intermediate which has been tentatively verified experimentally by others.
The preliminary results of a computational investigation into the mechanism for the methanolytic cleavage of a series of N-methyl N-aryl thiobenzamides catalyzed by a similar palladacycle complex is also presented, showing metal-assisted nucleophilic attack and leaving group departure.

abstract: PhD


title: Nonlinear Modeling of Inertial Errors by Fast Orthogonal Search Algorithm for Low Cost Vehicular Navigation

contributor:
Noureldin, Aboelmagd
Korenberg, Michael J.
Electrical and Computer Engineering

subject:
GPS
Inertial Navigation System
Kalman Filter
Fast Orthogonal Search
Land Vehicle Navigation
Inertial Sensors

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2012-01-22 01:26:11.477

abstract:
Due to their complementary characteristics, Global Positioning System (GPS) is usually integrated with standalone navigation devices like odometers and inertial measurement units (IMU). Recently, intensive research has focused on utilizing Micro-Electro-Mechanical-System (MEMS) grade inertial sensors in the integration because of their low cost. In this study, a reduced inertial sensor system (RISS) is considered. It comprises a MEMS grade single axis gyroscope, the vehicle built-in odometer, and two optional MEMS grade accelerometers. Estimation technique is needed to allow the data fusion of RISS and GPS. With adequate accuracy, Kalman filter (KF) fulfills this requirement if high-end inertial sensors are used. However, due to the inherent error characteristics of MEMS devices, MEMS-based RISS suffers from the non-stationary stochastic sensor errors and nonlinear inertial errors, which cannot be suppressed by KF alone. To solve the problem, Fast Orthogonal Search (FOS), a nonlinear system identification algorithm, is suggested in this research for modeling higher order RISS errors. FOS algorithm has the ability to figure out the system nonlinearity with a tolerance of arbitrary stochastic system noise. Its modeling results can then be used to predict the system dynamics. Motivated by the above merits, a KF/FOS module is proposed. By handling both linear and nonlinear RISS errors, this module targets substantial enhancement of positioning accuracy.
To examine the effectiveness of the proposed technique, KF/FOS module is applied on RISS with GPS in a land vehicle for several road test trajectories. Its performance is compared to KF-only method, both assessed with respect to a high-end reference. To evaluate navigation algorithm in real-time vehicle application, a multi-sensor data logger is designed in this research to collect online RISS/GPS data. KF/FOS module is transplanted on an embedded digital signal processor as well. Both the off-line and online results confirm that KF/FOS module outperforms KF-only approach in positioning accuracy. They also demonstrate reliable real-time performance.

abstract: PhD


title: Harvesting Consciousness:  The Impact of Seasonal Labour on the Transnational Political Identity of Guatemalan Migrants to Canada

contributor:
Lovell, W. George
Mullings, Beverley
Geography

subject:
Political Participation
Guatemala
Guatemala

abstract: Thesis (Ph.D, Geography) -- Queen's University, 2012-01-14 20:36:14.142

abstract:
The Temporary Agricultural Worker to Canada (TAWC) project was introduced in 2003 with the purpose of recruiting Guatemalan migrants to fill seasonal labour voids in Canada.  Workers contracted through TAWC directives have received minimal scholarly attention, given the infancy of the program and the substantial focus on Mexican migrants recruited through the Canadian Seasonal Agricultural Worker Program.  This dissertation illuminates the transnational political realities of Guatemalans by examining the impact that circular migration has on the subaltern migrant body.
Fieldwork was conducted in two sites, the first St. Rémi in Québec, the second Santiago Sacatepéquez in Guatemala.  Research findings underscore the transnational nature of the flow of hegemonic (discipline, insecurity, oppression, exploitation) and counter hegemonic (empowerment, liberation, collectiveness, security) political ideas and activities between the spaces traversed by migrants.  The study engages a multi-faceted ethnographic design in order to explore the spatiality of political consciousness, assessing Guatemalan migrant responses to a range of ideas and activities imparted by agencies of power.  These include both the Canadian and Guatemalan governments, the International Organization for Migration, and le Fondation des entreprises pour le recrutement de la main-d'oeuvre étrangère (FERME) along with a range of transnational supporting allies.  Nevertheless, the decision to (dis)engage in certain politicized conduct is largely dependent on the human agency of Guatemalan migrants, as they find the means to cope with the mounting pressures of seasonal migration.
A political economy perspective allows me to engage three debates that theoretically frame the transnational political identity of Guatemalan migrants.  These are: (1) processes of political transnationalism; (2) neoliberal agenda and mindsets; and (3) migrant political consciousness, with a particular emphasis on Foucauldian concepts of governmentality and Gramscian notions of hegemony and consciousness.  By engaging the (re)shaping of transnational political identity as a phenomenon influenced by agencies of power, and more importantly, the human agency of subaltern migrants, my dissertation emphasizes migrant (un)willingness to embrace and/or suppress certain resources that restructure political consciousness and political action.  The versatility and fluidity of transmigrant political identity reveal that the distinct realities of individuals are constructed by travelling back and forth, as seasonal labourers, between Guatemala and Canada.

abstract: Plan to publish a manuscript of my thesis

abstract: PhD


title: Power Converters for Electric Vehicles

contributor:
Jain, Praveen K.
Bakhshai, Alireza
Electrical and Computer Engineering

subject:
Electrical Engineering
Power Electronics

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2012-01-18 11:41:33.654

abstract:
This thesis presents topologies and control methods to improve the efficiency and dynamic response of Electric Vehicle (EV) power converters. There are three main converters in an EV power conditioning system: a plug-in AC/DC converter, a low-voltage DC/DC converter, and a three-phase inverter. The focus of this thesis is to improve the plug-in AC/DC converter and the low-voltage DC/DC converter.
A new topology is proposed to improve the efficiency and increase the reliability of the plug-in AC/DC converter. The plug-in AC/DC converter consists of a Power Factor Correction (PFC) stage, which is followed by a high voltage DC/DC converter for galvanic isolation. The proposed approach includes a simple and effective auxiliary circuit for the PFC stage, which guarantees soft-switching for the power switches.  Next, a current-driven full-bridge topology is proposed for the high-voltage DC/DC conversion stage, which guarantees soft-switching and eliminates voltage spikes across the output diodes. Also, two control approaches are proposed in order to improve the dynamic response of the AC/DC converter. The first controller is based on nonlinear differential flatness theory, which can be used to improve the transient response of the AC/DC converter. The second controller is based on an optimized stabilizing control-Lyapunov function, which extends the stability margins and improves reliability.
An optimized variable-frequency phase-shift controller is proposed for the low voltage DC/DC converter, which adaptively controls the amount of reactive current required to maintain soft-switching throughout the whole range of operation and minimizes the switching and conduction losses of the converter.
Mathematical analysis, simulation, and experimental results are presented to verify the performance of the proposed techniques.

abstract: There are some pending patent applications regarding this thesis.

abstract: PhD


title: Limited Lookahead Control of Discrete-Event Systems: Cost, Probability, and State Space

contributor:
Rudie, Karen
Computing

subject:
Discrete-Event Systems
Simulation Modelling
State-Space Analysis
Limited Lookahead

abstract: Thesis (Master, Computing) -- Queen's University, 2012-01-20 19:35:58.007

abstract: Discrete-Event systems (DES) is a framework in which problems are modelled as finite-state automata and a solution in the form of a supervisory control scheme can be automatically synthesized via an exhaustive search through the state space of the system. Various extensions to the standard DES framework have been introduced to allow it to be applied to a greater variety of problems. When the system in question is very large or varies with time, a limited lookahead policy can be adopted, in which control decisions are made on-the-fly by looking at finite-step projections of the behaviour of the system's underlying automata. This work presents a new approach to limited lookahead supervision which incorporates many of the extensions to DES that are already present in the literature, such as event probability and string desirability. When dealing with a limited lookahead technique, the projected system behaviour is represented as a lookahead tree with some depth limit decided on by the user. It can be difficult to strike a balance between the complexities associated with storing and analyzing the trees and the amount of information available to make decisions, both of which increase with depth. This work also presents a set of methods which are designed to aid in accurately estimating the state space of lookahead trees with the intent of simplifying the process of determining a favourable depth to use. Finally, the approaches introduced herein are applied to a simulation of an infectious disease outbreak, primarily to showcase them in action, but also for the possibility of illuminating any useful information for real-world health units.

abstract: M.Sc.


title: Bulk Hydrides and Delayed Hydride Cracking in Zirconium Alloys

contributor:
Daymond, Mark R.
Mechanical and Materials Engineering

subject:
Nuclear Materials
Hydride Phase Stability
Hydrogen Embrittlement
Zirconium Hydride
γ-hydride
Delayed Hydride Cracking

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-01-24 06:14:14.152

abstract:
Zirconium alloys are susceptible to engineering problems associated with the uptake of hydrogen throughout their design lifetime in nuclear reactors. Understanding of hydrogen embrittlement associated with the precipitation of brittle hydride phases and a sub-critical crack growth mechanism known as Delayed Hydride Cracking (DHC) is required to provide the engineering justifications for safe reactor operation.

The nature of bulk zirconium hydrides at low concentrations (< 100 wt. ppm) is subject to several contradictory descriptions in the literature associated with the stability and metastability of γ-phase zirconium hydride. Due to the differing volume expansions (12-17%) and crystallography between γ and δ hydride phases, it is suggested that the matrix yield strength may have an effect on the phase stability. The present work indicated that although yield strength can shift the phase stability, other factors such as microstructure and phase distribution can be as or more important. This suggests that small material differences are the reason for the literature discrepancies.

DHC is characterised by the repeated precipitation, growth, fracture of brittle hydride phases and subsequent crack arrest in the ductile metal. DHC growth is associated primarily the ability of hydrogen to diffuse under a stress induced chemical potential towards a stress raiser. Knowledge of the factors controlling DHC are paramount in being able to appropriately describe DHC for engineering purposes. Most studies characterise DHC upon cooling to the test temperature. DHC upon heating has not been extensively studied and the mechanism by which it occurs is somewhat controversial in the literature. This work shows that previous thermo-mechanical processing of hydrided zirconium can have a significant effect on the dissolution behaviour of the bulk hydride upon heating. DHC tests with γ-quenched, furnace cooled-δ and reoriented bulk hydrides upon heating and DHC upon cooling suggest that the amount of hydrogen in solution is the primary factor controlling the occurrence of DHC and consistent with the postulation that the stress induced chemical potential is the driving force for DHC.

abstract: M.A.Sc.


title: Metaboreflex-Induced Flow Improvement is Absent in Older Males With Type II Diabetes

contributor:
Tschakovsky, Michael E.
Kinesiology and Health Studies

subject:
Blood Flow
Type 2 Diabetes

abstract: Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2012-01-31 09:30:42.604

abstract:
Background: Exercise is widely recognized as the cornerstone of management of type II diabetes (T2D). However, it is also known that people with T2D have poor adherence to exercise regimens, which is largely thought to be because of poor exercise tolerance. Recent studies have suggested that this exercise intolerance may be caused by a reduction in exercising muscle blood flow. One physiological mechanism which could potentially contribute is the muscle metaboreflex (MMR). This mechanism is thought to be a pressure-based flow-improving mechanism, but as a result of reduced efficacy of vasodilators and sympatholytic agents, might in fact be restraining the flow-improvement in persons with T2D.

Hypothesis: Persons with T2D would not improve exercising muscle blood flow upon MMR activation. This absence of flow-improvement will be due to an augmented vasoconstriction in the exercising muscle.

Methods: T2D (n=7) and CTL (n=6) participants performed rhythmic forearm handgrip exercise at an intensity equivalent to 20% MVC for 9 minutes with and without the application of ischemic plantar flexion (IPF).  Forearm blood flow (FBF), mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), total peripheral resistance (TPR) and forearm vascular conductance (FVK) were quantified for the last thirty seconds of each of four time points during the protocol. Plasma norepinephrine was measured via deep venous and arterialized venous blood sampling.

Results: Steady state exercising FBF was increased in CTL but not in T2D during MMR activation (mean ± SE mL/min: CTLControl 161.16 ± 5.95, CTLMMR 212.72 ± 9.49, T2DControl 156.71 ± 13.08, T2DMMR 144.22 ± 10.55). This occurred despite similar increases in MAP, CO, HR, and TPR (across groups and treatment conditions, NS). FVK increased in CTL during the MMR protocol compared to the Control protocol, but decreased in the T2D group using the same comparison (mean ± SE mL/min/100 mm Hg: CTLControl 144.74 ± 5.63, CTLMMR 176.76 ± 11.99, T2DControl 143.29 ± 13.44, T2DMMR 103.53 ± 8.44).

Conclusions: In the exercise model utilized, persons with T2D do not demonstrate the MMR-induced flow improvement seen in CTL. This impaired muscle blood flow in T2D is the result of MMR induced exercising limb vasoconstriction.

abstract: M.Sc.


title: The Rise and Demise of the Free Trade Area of the Americas: A Case Study in Counter-Hegemony

contributor:
Bakan, Abigail
Political Studies

subject:
Global Governance
Regionalism
Gramsci
Free Trade
FTAA

abstract: Thesis (Ph.D, Political Studies) -- Queen's University, 2012-01-24 10:01:37.746

abstract: This dissertation examines the failure to achieve a final agreement for the Free Trade Area of the Americas(FTAA)at the 2005 Mar del Plata Summit of the Americas. The predominant explanation for this outcome highlights the economic asymmetries and the lack of economic interdependence between the participating states. In view of these structural impediments, based on original field interviews and extensive document analysis, the author goes a step further and argues that these factors were exacerbated by an ideological shift that took place during the decade that the FTAA was negotiated. Specifically, it is argued that the emerging consensus in the hemisphere that was in place at the launching of the FTAA negotiations in 1994 centered on the desirability of economic liberalization; this began to unravel in view of growing political challenges to neo-liberalism in many of the Americas’ social formations. This particular political challenge of economic liberalization emerged against the background of the failure of neo-liberal reforms to achieve their promised results, and the resultant socio-economic polarization. In many social formations, this polarization led to crises of authority, which sometimes opened the political arena to social forces that articulated, to different degrees, alternatives to neo-liberalism. In two countries of import for the FTAA, Venezuela and Brazil, governments were elected which challenged the United States’ leadership within the FTAA negotiations, based on a discourse of state sovereignty. In broader terms, the growing de-legitimization of neo-liberalism in the Americas engendered crises of authority in certain countries, notably in Venezuela and Brazil. This in turn brought forth political dynamics that constrained the United States’ hegemony in the hemisphere, which would have been consolidated by the FTAA. As such, this dissertation draws upon a Gramscian analysis to examine the manner in which crises of authority, rooted in the social formations of the hemisphere, came to be manifested within the institutional framework of the FTAA. Consequently, this work further demonstrates that global governance structures are not only mechanisms through which hegemony is disseminated and counter-hegemony is absorbed, but that they can serve as spaces where hegemony can be confronted and counter-hegemony articulated.

abstract: PhD


title: Experiences of Self-Management Among Young Women Living with Type 1 Diabetes Mellitus

contributor:
Edge, Dana S.
Keeping-Burke, Lisa
Nursing

subject:
Type 1 Diabetes
Self-Management
Lived Experience
Young Women

abstract: Thesis (Master, Nursing) -- Queen's University, 2012-01-24 18:35:33.911

abstract:
Introduction:
Women possess characteristics and experiences unique and different from men. Menstruation, pregnancy, puberty and menopause may present challenges for self-management, a prerequisite for those living with Type 1 diabetes mellitus (T1DM). The meaning and experiences of self-management have not been adequately explored from a young woman’s perspective within the diabetes literature.
                                       Purpose of the Study:
Blood glucose and glycosylated hemoglobin (HbA1c) values are keys for determining success in self-management among individuals living with T1DM; however, the values may enable feelings of vulnerability and worthlessness in individuals living with T1DM. Through learning about the experiences of young women, it was hoped that the meaning of self-management would be uncovered. The research question was: What are the experiences of self-management among young women with Type 1 diabetes mellitus?
                                        Methods and Methodology:
Descriptive phenomenology was used to uncover the experiences of self-management. Unstructured interviews with nine young women aged 22-30 years were conducted to uncover their lived experience. Data collection and analysis followed the methodical structure outlined by van Manen (1997).
                                       Findings:
Data analysis revealed five themes, and the essence of participants’ self-management experiences. Identified themes included: 1) elusiveness of control; 2) the dualism of technology; 3) forecasting and establishing routines; 4) dealing with the “ups and downs”; and, 5) interface with the health care team. The essence that emerged from the data was “being in balance”.
                                     Conclusions:
Self-management encompassed the desire and need to be in balance with one’s life and blood glucose levels. Self-management was something that evolved over time, and grew in complexity as phases progressed; it was something participants were still trying to grasp. Individual attitudes, goals, and self-management strategies dominated participants’ discourse in describing their hope of achieving and sustaining balance in their day-to-day lives.

abstract: MNSc.


title: Soil Carbon Dynamics Following Switchgrass Establishment for Bioenergy Production in Southeastern Ontario

contributor:
Scott, Neal
Geography

subject:
soil organic carbon
Ontario
soil fractionation
MRT
switchgrass
13C natural abundance

abstract: Thesis (Master, Geography) -- Queen's University, 2012-01-30 13:56:06.269

abstract: Switchgrass (Panicum virgatum), a perennial C4 grass species, has the capacity to not only improve the quality of the soil in which it grows but also promote soil carbon storage to offset rising atmospheric CO2.  This research investigated soil organic carbon (SOC) dynamics beneath switchgrass using natural abundance 13C and soil carbon fractionation following the establishment of this crop in a native and predominantly C3 plant region in southeastern Ontario.  I investigated SOC dynamics by sampling adjacent commercial switchgrass fields and appropriate paired control fields at sites where the time since switchgrass establishment varied from 4-11 years.  SOC and natural 13C abundance were measured in paired fields to assess management-induced changes in the quantity, source, and turnover time of soil carbon.  To better elucidate carbon cycling dynamics over a relatively short time since switchgrass establishment, multiple soil fractionation techniques were applied to better understand carbon dynamics of soil organic matter with various mean residence times.  Establishment of switchgrass results in marginal increases in SOC, primarily at sites where intensive soil management (i.e. tillage) practices preceded switchgrass establishment.  Changes were observed in some of the more labile SOC pools, as well as in the δ13C values of the bulk soil and soil carbon fractions, indicating that growing switchgrass was causing the incorporation of switchgrass-derived carbon into the soil.  Even resistant SOC pools, with turnover times of over 100 years, incorporated significant quantities of switchgrass carbon in 11 years.  Annual increases in SOC, however, were less than values reported elsewhere.  The potential for soil carbon storage exists, likely due to longer mean residence times of the carbon in soils beneath switchgrass compared with other cultivation systems.   Changes in SOC following switchgrass establishment related strongly to the amount of root biomass, time since establishment and prior soil management practices.  The decomposition rates derived in this research should be integrated into soil carbon modeling applications intended to support the emergence of switchgrass in southeastern Ontario.  The results of my research can advance soil carbon models and be used to make regional assessment of the potential impact of growing switchgrass for bioenergy in southeastern Ontario.

abstract: M.Sc.


title: International Co-operative Education Placements: Experiences of Canadian College Students

contributor:
Hutchinson, Nancy L.
Education

subject:
International
Co-operative Education

abstract: Thesis (Master, Education) -- Queen's University, 2012-01-25 17:23:11.267

abstract:
A number of international research studies have explored the benefits and challenges for post-secondary students who have experienced an international co-operative education  assignment (e.g., Bentley & Broons, 1998; Coll & Chapman, 2000; Coll, Pinyonatthagarn & Pramoolsook, 2003; Ward & Laslett, 2004; Wong & Coll, 2001). A small number of studies in this field have suggested that a well organized program includes pre-departure planning, focused orientation programs, and opportunities for reflection (Bentley & Broons, 1998; Ward & Laslett, 2004). Mentoring relationships have also been shown to support the success of workplace opportunities (Collins, 1993; Thuynsma, 1997; Van Gyn & Ricks, 1998). However, the results of the research that highlight the development of various traits during the international experience do not distinguish between pre-placement and post-placement student characteristics that contributed to the students’ success in the international experiences. Therefore more research is required.
	The purpose of this study was to understand and report on specific factors that contribute to successful international co-operative education experiences from the perspective of college students and the program co-ordinator.  The students and co-ordinator were all associated with a work integrated learning opportunity in an international business college program that requires students to complete an international co-operative experience. Three fundamental questions I set out to answer were:  (a) What role does the pre-placement program play in students’ success in the international co-operative experience? (b) What characteristics of students and workplace supervisors as perceived by the students contribute to successful international co-operative education experiences? (c) What role, if any, does mentoring by a workplace supervisor play in students’ successful international co-operative education experience?
	The study findings emphasized the importance of understanding the characteristics that support a successful experience and discuss the implementation of goals for program design and delivery. The findings within the first theme focused on What Helped Students Succeed in the International Placement, the second theme highlighted What Impeded Students’ Success in the International Placement and the final theme outlined Goals Achieved.  Most of the categories within the themes were anticipated in the research questions but what was surprising was there was little data on mentoring.

abstract: M.Ed.


title: Unequal Treatment: Reconciling Approaches to HIV and Tuberculosis in the Context of South Africa's National Strategic Plan for HIV, STIs and TB, 2012-2016

contributor:
Epprecht, Marc
Global Development Studies

subject:
HIV
South Africa
HIV exceptionalism
tuberculosis
human rights

abstract: Thesis (Master, Global Development Studies) -- Queen's University, 2012-01-26 11:26:48.975

abstract: South Africa faces among the world's highest burdens of both HIV and TB. These diseases affect not only the same populations, but often the same patient; HIV/TB co-infection has a compounding effect that creates a greater public health problem than the sum of its parts. In recognition of the need to address HIV/TB co-infection, South Africa is integrating the responses to both diseases under the National Strategic Plan for HIV, STIs and TB, 2012-2016. However, the two diseases have previously been addressed in very different ways, particularly when it comes to human rights considerations. Rather than a reconciliation of these two approaches, the NSP more closely resembles the ongoing response to HIV; while this approach may yield some benefits when applied to TB, it also risks undermining the unique characteristics of TB as well as its overall role in the co-epidemic, with potential repercussions for the effectiveness of the NSP. Through examining the historical roots of these approaches, both in South Africa and internationally, this paper explores how different factors, including the way different stakeholders have engaged with each, have influenced the development of the NSP, and what the implications are for its effective implementation. It is hoped that by focusing attention on TB, the stakeholders charged with monitoring and implementing the NSP will recognize the necessity of giving due consideration to both diseases in enacting a unified response to the co-epidemic.

abstract: M.A.


title: The genomic consequences of sexual selection

contributor:
Chippindale, Adam K.
Biology

subject: evolution biology

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2012-01-25 19:27:08.17

abstract: Sex-differences in phenotype, development, and life-history can alter the strength of selection experienced by males and females. In particular, theoretical models have demonstrated that differences in the strength of selection between the sexes can influence the deleterious mutation load of populations. Stronger selection acting on males, via the action of sexual selection, could lower the mutation load for females if deleterious mutations tend to be harmful for both sexes. The necessary data to evaluate these models have been lacking, however, as most empirical studies of mutations have overlooked the fundamental differences between the sexes. Using the IV laboratory-adapted population of Drosophila melanogaster, I have measured the sex-specific impact of mutations in both sexes. This was done both for mutations naturally segregating in IV and for new mutations occurring on the X-chromosome. For both classes of mutations, males suffered a greater selective cost than females, and the mutations responsible were deleterious in both sexes. Further characterization of the male fitness phenotype revealed widespread decline in sexually selected characters combined with an increase in the correlation between sexually selected traits and viability, indicative of pleiotropy between new mutations. My work establishes the necessary conditions for sexual selection to reduce the mutation load of females, and helps fill a crucial gap in our understanding of the consequences of deleterious mutations.

abstract: PhD


title: From the Teacher's Perspective: The Complex Nature of Facilitating Volunteer Abroad Programs in Ontario Secondary Schools

contributor:
Tiessen, Rebecca
Global Development Studies

subject: experiential pedagogy volunteer global citizenship abroad education development

abstract: Thesis (Master, Global Development Studies) -- Queen's University, 2012-01-26 13:15:26.772

abstract: The following study has been designed to address gaps in the volunteer abroad literature with respect to this growing phenomenon within Ontario’s secondary school system.  Volunteer abroad programs at the secondary school level reflect a combination of attributes from study abroad, international service learning and volunteer tourism and are influenced by the rhetoric of global citizenship.  As studies have shown that educators play an important role in shaping the volunteer abroad experience for their students, specifically in relation to how they choose sending and host organizations, integrate pre-departure training and facilitate reflection during and after the time abroad, this study includes an interpretive analysis of ten semi-structured interviews conducted with Ontario secondary school teachers who have facilitated volunteer abroad programs between the years 2006 and 2011.  Interview responses have been critically analyzed through the lens of the global citizenship discourse, post-colonial studies and critical pedagogy theory in order to make sense of the nuances involved in how teachers conceptualize the volunteer abroad experience they provide for their students.  Throughout this thesis I argue that teachers must engage in self-reflexive and collaborative practices in order to challenge their assumptions regarding the impacts of these programs on their students and host communities in the Global South.

abstract: M.A.


title: Statistical Modeling and Analysis for Survival Data with a Cure Fraction

contributor:
Peng, Paul Yingwei
Mathematics and Statistics

subject:
proportional hanzards model
Length-biased Data
cure model
Nonparametric estimation
Nonparametric Maximum Likelihood
transformation model

abstract: Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2012-01-26 09:53:08.127

abstract: The analysis of survival data with a possible cure fraction has attracted much interest in the last two decades. Various models and estimating methods have been proposed for such data and they have been applied in many fields, especially in cancer clinical trials. In the thesis, we consider some new general cure models, which include existing survival models as their special cases. We also consider a nonparametric estimation of cure rate. The estimator is proved consistent and asymptotically normal. We also consider the application of proportional density for cure data and the analysis of length-biased cure data.

abstract: Some chapters are still under revision for journal publication

abstract: PhD


title: Receipt of Cardiac Care Following Hospitalization for an Acute Myocardial Infarction for Individuals With a History of Depression or Schizophrenia

contributor:
Lévesque, Linda E.
Stuart, Heather
Community Health and Epidemiology

subject:
Quality of Care
Stigma
Depression
Acute Myocardial Infarction
Disparity
Schizophrenia

abstract: Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2012-01-26 11:17:27.964

abstract:
Background: The goal of this study was to improve upon methodological limitations of previous studies to determine the existence and source of differences in the cardiac care of individuals with a history of depression or schizophrenia. The selected outcomes were three cardiac procedures: catheterization, percutaneous transluminal coronary angiography (PTCA), and coronary artery bypass graft (CABG); and three cardiac pharmaceuticals: beta-blockers, angiotensin converting enzyme (ACE) inhibitors and statins.
Methods: This population-based retrospective cohort study consisted of 309, 790 individuals diagnosed with an AMI and admitted to an acute care hospital in Ontario between April 1, 1995 and March 31, 2009. The time-to-intervention for the depression and schizophrenia was estimated and compared to those without a mental disorder using Cox Proportional Hazards regression. Subgroup analyses were performed to evaluate the interaction between well-established confounders and the receipt of a cardiac intervention.
Results: Persons with a history of depression were found to be more likely to receive a catheterization (HR=1.42, 95% CI=1.34-1.50) or PTCA (HR=1.48, 95% CI=1.40-1.57) if they had no previous CVD history, but were less likely to receive a catheterization (HR=0.71, 95% CI=0.51-0.99) or PTCA (HR=0.64, 95% CI=0.39-1.06) if they had a CVD history. In addition individuals with depression were less likely to receive a CABG, especially if they had a history of CVD (HR=0.38, 95% CI=0.24-0.60). Persons with a history of schizophrenia were found to be just as likely to receive a catheterization (HR=0.90, 95% CI=0.70-1.15) or a PTCA (HR=0.83, 95% CI=0.62-1.11). The likelihood of receiving a beta-blocker or statin was comparable or higher for persons with a history of depression (HR=1.07, 95% CI=1.03-1.11; 1.27, 95%
ii i
CI=1.22-1.32, respectively) and comparable for persons with a history of schizophrenia (HR=0.90, 95% CI=0.79-1.02; HR=0.97, 95% CI=0.83-1.14, respectively), with a small but significant prior drug use effect modification.
Interpretation: Persons with depression or schizophrenia with no CVD history are just as likely to receive most recommended cardiac care interventions compared to those without a mental disorder. The source of the differences in care for individuals with a CVD history with depression and schizophrenia needs to be further explored.

abstract: M.Sc.


title: Science Imagined | Literature Realized: Truth and Fiction in Canada

contributor:
Willmott, Glenn
English

subject: Science; Canadian Literature; Postmodernism; Theory; Religion; Faith

abstract: Thesis (Ph.D, English) -- Queen's University, 2012-01-26 11:50:12.999

abstract: In Canada, writers of long fiction have recently begun to employ representations of science and to use scientific theories to construct narratives that investigate issues of class, race, sexuality, faith, truth and the ontological understanding of human existence. This turn towards science in creative works of art suggests that scientific discourse in the early twenty-first century has become a space from which to respond to questions about the search for truth after the rise of poststructuralist theory and postmodern culture. My work investigates this recent turn towards science in contemporary Canadian literature as a way of reevaluating the idea that science is associated with a teleological movement towards human progress, and to analyze how scientific representations re-imagine faith and ethics from a secular perspective. The recent shift towards science in the literature of Canada in English suggests a questioning of social conditions which place the human within epistemological spectrums between truth and fiction, faith and reason, and the individual and the universal. In my dissertation questions related to belief and truth are bound up in a cross-textual study that looks at how Canadian literature reevaluates important debates among theology, art, and science in order to access a humanist interpretation of different possible realities. My dissertation investigates: The Bone Sharps (2007) by Tim Bowling; Curiosity: A Love Story (2010) by Joan Thomas; The Origin of Species (2008) by Nino Ricci; The Memory Artists (2004) by Jeffrey Moore; Player One: What is to Become of Us (2010) by Douglas Coupland; Atmospheric Disturbances (2008) by Rivka Galchen, and  The Evolution of Inanimate Objects: The Life and Collected Works of Thomas Darwin (1857-1879) (2010) by Harry Karlinsky.

abstract: I will be preparing the thesis for publication.

abstract: PhD


title: Cultivating Governance: The Production of Mushrooms and Mushroom Workers

contributor:
Mullings, Beverley
Geography

subject:
Governmentality
Discipline
Immigration
Mushrooms
Farmworkers
Gender
Farm work

abstract: Thesis (Master, Geography) -- Queen's University, 2012-02-06 22:57:27.043

abstract:
This thesis examines how the liberalization of United States agriculture has affected the everyday experiences of labor, and laborers. Centered on a case study of mushroom production in Southern Chester County, Pennsylvania, this thesis explores the role of governmentality in shaping the daily work experience of labor employed in the industry.
Situated within feminist geographic debates regarding gender and work, this thesis argues that normalized and stereotypical understandings of gender, ethnicity, and immigrant status have become tools of discipline that encourage particular performances of work within mushroom houses. The disciplinary strategies explored in this thesis are comprised of rules, procedures, regulations, and dispositions, and are deployed in a  complementarily manner to maximize profit generated by laborers. Ultimately these disciplinary measures have become integral for Southern Chester County to both maximize profits and maintain its prominent location as the largest mushroom cultivating region in the United States.

abstract: M.A.


title: Comparative Modeling, Simulation, and Control of Rotary Blasthole Drills for Surface Mining

contributor:
Daneshmend, Laeeque K.
Mechanical and Materials Engineering

subject:
Drilling
Control System
Mining

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-01-31 13:41:54.577

abstract:
Most rotary blasthole drills used in the mining industry today are equipped with automatic control systems. However, few, if any, implement closed-loop feedback control of the drilling process itself. This thesis investigates the potential for such control on a large rotary electric blasthole drill. The control strategy examined is Proportional-Integral-Velocity (PIV) control. The drill was successfully equipped with a data logger, and a comprehensive set of drilling data was gathered at an open pit taconite mine in northern Minnesota. This data set was used to model the dynamics of both the feed and rotary actuators.
A drilling process software simulator, based on hydraulic blasthole drill data originally developed in previous work [Aboujaoude 1991], was successfully replicated in Simulink, and thoroughly documented, overcoming a major shortcoming in Aboujaoude’s work which provided incomplete information on the simulator implementation. The control strategy from the previous work was successfully integrated with the new process simulator, and its performance validated by comparison with the results presented in the previous work.
The drilling process simulator was then modified by replacing the actuator dynamics with the models identified for the electric drill. The modified simulator was validated, and the behaviour of the system with the new actuator models while under feedback control was observed. The controller gains were re-tuned to achieve acceptable drilling performance with the new actuator models. This resulted in a prototype controller ready for field testing on the large rotary electric blasthole drill. In addition, this thesis has produced a fully documented drilling process simulator, suitable as a platform for future research.

abstract: M.A.Sc.


title: Nature and time-scale of bed morphological adjustments towards equilibrium in meandering streams: an experimental study

contributor:
da Silva, Ana Maria Ferreira
Civil Engineering

subject:
Laboratory tests
Meandering streams
Time factors
River beds
Topography
Equilibrium

abstract: Thesis (Ph.D, Civil Engineering) -- Queen's University, 2012-01-26 16:43:52.424

abstract:
This thesis concerns the nature and time-scale of bed morphological adjustments towards equilibrium in alluvial meandering streams. Following the prevailing approach, the stream centrelines are assumed to follow sine-generated curves, the banks are fixed, and the flow is turbulent and sub-critical. The movable bed is flat at time t = 0; at t = Tb, the bed reaches its equilibrium or developed state.
	The specific objectives of this thesis are: 1) to develop a predictive equation for the bed development time Tb; 2) to determine the rate of growth of pool-bar complexes in meandering streams; and 3) to determine whether or not the large-scale, curvature-induced erosion-deposition zones of developing beds migrate upstream or downstream throughout their development. This thesis builds on the preliminary work and experimental tests by Binns (2006).
The duration of bed development is found to be proportional to the square of the flow width B and inversely proportional to the channel-averaged bed-load rate (qsb)av, the proportionality factor being a function of the initial deflection angle (i.e., stream sinuosity). The form of this function is revealed on the basis of an extensive series of experimental runs carried out in meandering channels of varying values of the initial deflection angle (i.e., 20, 45, 70 and 95 degrees).
In the present tests, the temporal development of the bed from time t = 0 to t = Tb was monitored by periodically stopping the flow in order to measure changes in bed surface elevation. In all runs the bed was observed to deform rapidly during the early stages of the run and slow down considerably as the bed approached equilibrium conditions. Once formed, the location of the erosion-deposition zones remained invariant in flow plan with the passage of time. Results from the runs are used to provide insight into the nature of the deformed bed in meandering streams. An expression describing the temporal rate of growth of pool-bar complexes in meandering streams of varying sinuosity is also proposed. The practical application of the equation for Tb is illustrated with available field data.

abstract: This thesis is to be restricted from publication until the final two manuscripts (presented in Chapters 4 and 5 of the thesis) are accepted for publication.

abstract: PhD


title: Understanding Magnetic Flux Leakage from Gouges and Dents Containing Gouges

subject: Gouge MFL

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2012-01-29 14:13:54.535

abstract:
Magnetic flux leakage (MFL) is the most widely used non-destructive evaluation (NDE) technique for operating gas and oil transmission pipelines. The Queen’s Applied Magnetics Group (AMG) has been studying MFL signals from dents for the past 5 years, and recently began considering MFL signals from gouges, and gouge/dent combinations.
It is believed that MFL signals from gouges may arise from three factors: the gouge geometry, residual stresses, and a severe plastically deformed layer that is often present at the base of the gouge. The last factor has been studied by another MSc student, Kris Marble.  The present thesis work primarily considers the effects of the first two factors – gouge geometry in combination with residual stress.
Samples containing realistic gouges, produced under field-like conditions, were obtained from two sources - Stress Engineering Services (SES) in Houston, Texas and GdF Suez in St. Denis, France.  At SES, ten different gouges on five pipes (two on each pipe) with increasing severity were produced for the current thesis project. Three gouged pipe samples were obtained from GdF Suez.
	The bulk of the thesis study involved experimental MFL measurements made for each of the gouges and gouge/dents of SES samples in the study, on both the outer and inner surface, and in some cases when the pipe wall was under pressure.  The experimentally obtained MFL signals were interpreted by comparison with the expected MFL geometry-only signals (obtained using magnetic modeling) along with the knowledge of the residual stress information obtained from the neutron diffraction measurements.  Various results were obtained and concluded.
	The neutron diffraction was also done on three GdF Suez samples. The results from one sample were used to model the residual stress distribution around the sample and the modeled MFL signals were compared with the experimental MFL signals. The modeled signals are able to account for most features in the experimental results.

abstract: M.Sc.


title: Process Sedimentology and Three-Dimensional Facies Architecture of a Fluvially Dominated, Tidally Influenced Point Bar: Middle McMurray Formation, Lower Steepbank River Area, Northeastern Alberta, Canada

contributor: Geological Sciences and Geological Engineering

subject:
Oils Sands
Point Bars
Fluvial-Marine Transition Zone
Process Sedimentology

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-01-30 13:25:32.53

abstract:
Within the middle McMurray exposures along the Steepbank River (Steepbank River Outcrops 3 and 4), nine recognized facies can be divided into three genetically related groups: sand-dominated facies, inclined heterolithic stratification (IHS) facies and mixed heterolithic facies.  Together, these facies are interpreted to represent a fluvially dominated, tidally influenced point bar that experienced strong seasonal variation in river discharge.  Annual fluctuations between river-flood stage and low-flow stage are responsible for the deposition of fluvially dominated sand beds alternating with brackish, tidally influenced mud beds that cover the point-bar surface as members of the various IHS facies.  The dichotomy of fluvially dominated sand deposition and brackish-water ichnology of the mud beds represents the annual migration in position of the tidal and salinity nodes caused by fluctuations in fluvial discharge.
Recognition of metre-scale cycles (MSCs) of alternating sandier and muddier intervals within the IHS facies imply that decadal climate cycles, likely caused by fluctuations in ocean and/or solar dynamics, influenced point-bar deposition.  These MSC packages are defined by an upward decrease in sand-bed thickness, an upward increase in mud-bed frequency, and an upward increase in bioturbation intensity, all occurring on a metre scale.  MSCs are an important architectural element of these large-scale tidal-fluvial point bars because they are predictable, repeatable and continuous around the point bar.
Analysis of paleocurrents relative to inclined-heterolithic-stratification bedding planes indicates that bend-flow modifications (BFMs) were effective in redistributing flow around the point bar. Furthermore, this suggests that Outcrop 3 is representative of an upstream-to-bend-apex transition within a large-scale point-bar planform.
Recognition of multiple channels at Outcrop 4 was based on large-scale erosional truncation, IHS bed-orientation changes, large cumulative thicknesses of the middle McMurray, thick sand-package thicknesses, changes in relative scale of sedimentary structures, and the occurrence of large mud clasts.  Similarities in depositional expression between channels suggest autogenic channel stacking (within-valley stacking), rather than the stacking of separate valleys. Finally, discordant paleocurrents within the basal sand-dominated facies are likely representative of amalgamated channel-bottom facies from several generations of channel. This suggests that only the upper intervals of basal sand-dominated facies are genetically linked to the overlying IHS facies.

abstract: M.A.Sc.


title: Use of Spatially Non-Uniform Electric Fields for Contact-Free Assembly of Three-Dimensional Structures from Colloidal Particles

contributor:
Docoslis, Aristides
Chemical Engineering

subject:
AC electrokinetics
colloidal assembly
electric fields
dielectrophoresis

abstract: Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-01-30 14:17:23.747

abstract: In this thesis, three speciﬁc research contributions to the use of non-uniform electric ﬁeld driven colloidal assembly are described. The ﬁrst relates to experimental work using dielectrophoretic and electrohydrodynamic forces (electroosmosis) to shape three-dimensional colloidal structures. Formation and stabilization of close-packed three-dimensional structures from colloidal silica was demonstrated, using gelation of pluronic F-127 to preserve medium structure against suspension evaporation. Stabilization of ordered structures was shown to be a signiﬁcant challenge, with many of the conventional techniques for immobilizing colloidal crystals being ineﬀective. Secondly, the signiﬁcance of electrohydrodynamic ﬂows resulting from electric and particle concentration (entropic) gradients during the assembly process was demonstrated using numerical simulations based on a thermodynamic framework. These simulations, as well as experimental validation of assembly and the presence of ﬂuid ﬂows, showed that assuming equilibrium behavior (stationary ﬂuid ﬂow), a common assumption for most modelling work to date in these systems, is inappropriate at all but the most dilute concentration cases. Finally, the relevance of multiparticle eﬀects on electric-ﬁeld induced phase transitions of dielectric colloids was demonstrated. The eﬀect of multiparticle/multiscattering eﬀects on the suspension permittivity were accounted for using semi-empirical continuum permittivity formulations which have been previously shown to describe a wide variety of solid packing structures, including face-centered cubic and other colloidal crystal structures. It was shown that multiparticle eﬀects have a signiﬁcant impact on both the coexistence (slow phase separation) and spinodal (fast phase separation) behavior of dielectric suspensions, which has not been demonstrated to date using a continuum framework.

abstract: PhD


title: Temperature Modulation of the Effects of Repetitive Anoxia on Potassium Homeostasis in the Brain of Drosophila melanogaster

contributor:
Robertson, Mel
Biology

subject:
Hypoxia
Drosophila
Brain
Extracellular Potassium Concentration
Repetitive Anoxia
Temperature
Homeostasis
Melanogaster

abstract: Thesis (Master, Biology) -- Queen's University, 2012-01-30 13:03:10.913

abstract: Oxygen can be limited at the environmental (e.g. flood-prone burrows) or cellular (e.g. stroke, heart attack) levels. O2 deprivation in nervous tissue depolarizes cell membranes, incrementing extracellular potassium concentration ([K+]o). Consequently, [K+]o can be used to assess neural failure during anoxia. The effect of temperature on the maintenance of brain [K+]o homeostasis in male and female Drosophila melanogaster (W1118) was assessed during repeated anoxic comas induced by N2 gas. Brain [K+]o was continuously monitored using K+-sensitive microelectrodes while body temperature was gradually increased/decreased using a Peltier plate. Once the desired temperature was reached (16°C/17°C, 23°C or 29°C/30°C), it was maintained for the rest of the experiment and the fly was subjected to repeated anoxic bouts. Repetitive anoxia resulted in a loss of the ability to maintain [K+]o baseline at ~10 mM. In both sexes, the total [K+]o baseline variation (D[K+]o) was augmented at 30°C (D[K+]o male = 119.2 ± 21.9 mM; D[K+]o female = 51.2 ± 8.1 mM), whereas 16°C stabilized [K+]o baseline for the duration of the experiment (D[K+]o male = 17.5 ± 4.1 mM; D[K+]o female = 16.9 ± 6.8 mM). Additionally, D[K+]o in males was significantly greater (114.3 ± 10.5 mM ) than in females (36.1 ± 10.5 mM) at 23°C. Under reduced dehydration, experiments performed only in males showed the same trends although the D[K+]o values where considerably reduced at 17°C (D[K+]o male = -1.0 ± 1.3 mM) and 23°C (D[K+]o male = 17.3 ± 1.5 mM) and increased at 29°C (D[K+]o male = 332.7 ± 83.0 mM). It was concluded that 1) N2-delivery patterns consisting of long anoxia, short normoxia and high cycle frequency increased disruption of brain [K+]o baseline maintenance, 2) males were more susceptible to repeated anoxia than females at room temperature, and 3) hypothermia had a protective effect on brain K+ homeostasis during repetitive anoxia. Male flies are suggested as a useful model for examining deleterious consequences of O2 reperfusion with extensive application on therapeutical treatment of stroke or heart attack.

abstract: M.Sc.


title: Tomographic Imaging on a Cobalt Radiotherapy Machine

subject:
Radiation
Radiotherapy
Cobalt
Tomography
Radiology
Medical Physics

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2012-01-30 12:56:56.075

abstract:
Cancer is a global problem, and many people in low-income countries do not have access to the treatment options, such as radiation therapy, that are available in wealthy countries. Where radiation therapy is available, it is often delivered using older Co-60 equipment that has not been updated to modern standards.

Previous research has indicated that an updated Co-60 radiation therapy machine could deliver treatments that are equivalent to those performed with modern linear accelerators. Among the key features of these modern treatments is a tightly conformal dose distribution-- the radiation dose is shaped in three dimensions to closely match the tumour, with minimal irradiation of surrounding normal tissues. Very accurate alignment of the patient in the beam is therefore necessary to avoid missing the tumour, so all modern radiotherapy machines include imaging systems to verify the patient's position before treatment.

Imaging with the treatment beam is relatively cost-effective, as it avoids the need for a second radiation source and the associated control systems. The dose rate from a Co-60 therapy source, though, is more than an order of magnitude too high to use for computed tomography (CT) imaging of a patient. Digital tomosynthesis (DT), a limited-arc imaging method that can be thought of as a hybrid of CT and conventional radiography, allows some of the three-dimensional selectivity of CT but with shorter imaging times and a five- to fifteen-fold reduction in dose.

In the present work, a prototype Co-60 DT imaging system was developed and characterized. A class of clinically useful Co-60 DT protocols has been identified, based on the filtered backprojection algorithm originally designed for CT, with images acquired over a relatively small arc. Parts of the reconstruction algorithm must be modified for the DT case, and a way to reduce the beam intensity will be necessary to reduce the imaging dose to acceptable levels. Some additional study is required to determine whether improvements made to the DT imaging protocol translate to improvements in the accuracy of the image guidance process, but it is clear that Co-60 DT is feasible and will probably be practical for clinical use.

abstract: M.A.Sc.


title: Field Monitoring of Landslide Deformation Using Low Altitude Photogrammetry

contributor:
Take, W. Andy
Civil Engineering

subject:
Photogrammetry
Landslide Monitoring
Landsliding

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2012-01-30 16:20:27.13

abstract: The Ottawa/Gatineau region has significant deposits of sensitive glacial marine clay. As these deposits have risen due to isostatic rebound, these materials have been incised by various watercourses, carving river valleys throughout the region. The slopes of these river banks are susceptible to retrogressive slides with significant travel distances. A novel method of monitoring changes in these landslides has been developed and is explained in this thesis. Using a tethered blimp as an aerial photo platform, high resolution digital elevations models (DEM) with accuracies of ±0.49m on vegetated slopes have been created using photogrammetry. These DEMs have been created for a several photos sets taken over time. This allows changes over time to be monitored. The use of ground control points (GCP) allows for the complete three dimensional movement of discrete points to be monitored over time. The photogrammetric DEM have been compared to similar DEM derived from LiDAR surveying. By complimenting these surveys with historical aerial photos it is possible to develop better models of landslide failure processes, which will ultimately provide better predictions of movements and failure. When movements and failures can accurately be predicted it will then be possible to better manage the risk associated with these landslides events.

abstract: M.A.Sc.


title: The Built Environment and Obesity-Related Behaviours in Canadian Youth

contributor:
Janssen, Ian
Pickett, William
Community Health and Epidemiology

subject:
Schools
Eating behaviours
Youth
Urban sprawl
Physical activity
Geographic information systems
Built environment
Obesity
Food retail environment

abstract: Thesis (Ph.D, Community Health & Epidemiology) -- Queen's University, 2012-01-30 19:36:47.354

abstract:
The objectives of this thesis were to examine the relationship between the built environment and obesity-related behaviours in Canadian youth, and to address measurement issues relevant for studying these relationships. The thesis is comprised of four manuscripts.
The first manuscript determined the accuracy of the food retailer locations surrounding 34 schools in Ontario as provided by two geographic information system (GIS) databases. The GIS locations of 25% of the food retailers were located within 15 m of their actual location, 50% were within 25 m, and 75% were within 50 m. These values did not differ by GIS database source.
The second manuscript examined the association between the presence of food retailers surrounding schools and students’ lunchtime eating behaviours. It also determined whether a circular or road network buffer provided a better geographic boundary of the food retail environment surrounding schools. It was carried out in 6,971 9th and 10th grades students from 158 schools. The presence of food retailers near schools was strongly associated with students regularly eating their lunch at a snack-bar, fast-food restaurant or café.  The road network buffers provided the better measure of the food retail environment.
The third manuscript determined the optimal buffer size of the food retail environment surrounding schools. Six road network buffers were created around 158 schools.  These ranged in size from 500 m to 5000 m. Results indicated that the 1000 m buffer was the optimal size.
The fourth manuscript explored associations between urban sprawl and active transportation, moderate to vigorous physical activity (MVPA) and overweight/obesity in 7,017 youth aged 12 to 19 who resided in one of Canada's 33 Census Metropolitan Areas. Increasing levels of sprawl were modestly associated with increased active transportation (only among 12 to 15 year olds) and MVPA. No associations were found for overweight/obesity.
Taken together, the results from this thesis provide a better understanding of the role of the built environment on obesity-related behaviours in Canadian youth. Important measurement issues in this topic area were also addressed.

abstract: PhD


title: Electrokinetically Enhanced Sampling and Detection of Bioparticles With Surface Based Biosensors

subject:
Biosensor
Electrothermal Flow
Raman Spectroscopy
Cantilever
Dielectrophoresis
Numerical Simulations
Microelectrode Design
AC Electrokinetics

abstract: Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-01-30 19:23:48.958

abstract: Established techniques for the detection of pathogens, such as bacteria and viruses, require long timeframes for culturing. State of the art biosensors rely on the diffusion of the target analyte to the sensor surface. AC electric fields can be exploited to enhance the sampling of pathogens and concentrate them at specific locations on the sensor surface, thus overcoming these bottlenecks. AC electrokinetic effects like the dielectrophoretic force and electrothermal flows apply forces on the particle and the bulk fluid, respectively. While dielectrophoresis forces pathogens towards a target location, electrothermal flows circulates the fluid, thus replenishing the local concentration. Numerical simulations and experimental proof of principle demonstrate how AC electrokinetics can be used to collect model bioparticles on an antibody functionalized selective surface from a heterogeneous solution having physiologically relevant conductivity. The presence of parallel channels in a quadrupolar microelectrode design is identified as detrimental during the negative dielectrophoretic collection of bioparticles at the centre of the design while simultaneously providing secondary concentration points. These microelectrodes were incorporated onto the surface of a novel cantilever design for the rapid positive dielectrophoretic collection of Escherichia coli bacteria and enabled the subsequent detection of the bacteria by measuring the shift in the resonance frequency of the cantilever. Finally, a proof of principle setup for a Raman coupled, AC electrokinetically enhanced sampling and detection of viruses is shown where the presence of M13 phages are identified on a selective antibody functionalized surface using Raman spectroscopy.

abstract: Research is involved in a patent application.

abstract: PhD


title: Structural Benefits of Hempcrete Infill in Timber Stud Walls

contributor:
MacDougall, Colin
Civil Engineering

subject:
Hempcrete
Column on Elastic Foundation
Timber Column

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2012-01-30 21:18:13.842

abstract: Due to an increase in environmental consciousness in the construction industry there has been increasing interest in using natural building materials like rammed earth construction, straw bale construction and hempcrete construction. These materials have very small embodied energy and are carbon negative or carbon neutral. Hempcrete is a bio-composite mix made up of hemp shive, lime, cement and water. There has been extensive research undertaken on the thermal, acoustic, and mechanical properties of hempcrete. It has low density, good thermal and acoustic insulation properties, and can passively regulate humidity in a built environment. However it also has low compressive strength and modulus of elasticity. Thus hempcrete cannot be used as a direct load bearing material but can used as an infill material in timber stud walls. This thesis investigates how hempcrete can have beneficial structural effects by preventing buckling of timber (increasing the buckling load) columns when used as an infill in between columns in a timber stud wall. Eight timber walls were constructed (both half scale -1200mm high; and full scale – up to 2133mm high) with varying column dimensions. Six of the walls were infilled with hempcrete of varying density. Two walls were not infilled and were baseline tests. All walls were tested in compression. It was found that high density hempcrete (715 kg/m3) not only prevented weak axis buckling of columns but also carried some direct load. Low density hempcrete was also successful in preventing weak axis buckling of the infilled walls. In-filled walls failed in strong axis buckling at a load twice (for half scale walls with 38x89mm columns) or 4 times(full scale walls with 38x235mm columns) that of the unfilled walls. An analytical model based on buckling of a strut on an elastic foundation was proposed to predict the maximum strength hempcrete can add to a wall by preventing buckling. The timber column strength equations from CSA –O86-01 closely predicted the buckling load of the walls from the experiments. The results from the model were also put in design equations from CSA –O86-01 to predict practical failure loads if the walls failed by buckling into hempcrete. Although only a single test result was available, it was in good agreement with the model predictions.

abstract: M.A.Sc.


title: Development and Validation of Large-Sized Engineered Cartilage Constructs in Full –Thickness Chondral Defects in a Rabbit Model

contributor:
Waldman, Stephen D.
Chemical Engineering

subject:
Tissue Engineering
Implantation
Chondral Defects
Articular Cartilage

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2012-01-31 01:03:15.276

abstract:
Long-term applicability of current surgical interventions for the repair of articular cartilage is jeopardized by the formation of mechanically inferior repair tissue. Cartilage tissue engineering offers the possibility of developing functional repair tissue, similar to that of native cartilage, enabling long-lasting repair of cartilage defects. Current techniques, however, rely on the need for a large number of cells, requiring substantial harvesting of donor tissue or a separate cell expansion phase. As routine cell expansion methods tend to elicit negative effects on cell function, the following study describes an approach to generate large-sized engineered cartilage constructs (≥ 3 cm2) directly from a small number of immature rabbit chondrocytes (approximately 20,000), without the use of a scaffold. After characterizing the hyaline-like engineered constructs, the in vivo repair capacity was assessed in a chondral defect model in the patellar groove of rabbits.

In vitro remodeling of the constructs developed in the bioreactor occurred as early as 3 weeks, with the histological staining exhibiting zonal differences throughout the depth of the tissue. With culturing parameters optimized (3 weeks growth under 15 mM NaHCO3), constructs were grown and implanted into critical-sized 4 mm chondral defects. Assessed after 1, 3 and 6 months (n=6), implants were scored macroscopically to evaluate integration and survival of the implants. Out of 18 rabbits, 16 received normal or nearly normal over-all repair assessment. Histological and immunohistochemical evaluation showed good integration with surrounding cartilage and underlying subchondral bone. Architectural remodeling of the constructs was present at each time point, with the presence of flattened chondrocytes at the implant surface and columnar arrangement of chondrocytes in deeper zones. The observation of in vivo remodeling was also supported by the changes in biochemical composition of the constructs. At each time point, constructs had a collagen to proteoglycan ratio similar to that of native cartilage (3:1 collagen to proteoglycan). In contrast, the repair tissue for each control group was inferior to that produced with treated defects. These initial results hold promise for the generation of engineered articular cartilage for the clinical repair of cartilage defects without the limitations of current surgical repair strategies.

abstract: M.A.Sc.


title: Empirical Studies of Code Clone Genealogies

contributor:
Zou, Ying
Electrical and Computer Engineering

subject:
clone genealogies
code clones
software engineering

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2012-01-31 11:39:10.503

abstract: Two identical or similar code fragments form a clone pair. Previous studies have identified cloning as a risky practice. Therefore, a developer needs to be aware of any clone pairs so as to properly propagate any changes between clones. A clone pair experiences many changes during the creation and maintenance of software systems. A change can either maintain or remove the similarity between clones in a clone pair. If a change maintains the similarity between clones, the clone pair is left in a consistent state. However, if a change makes the clones no longer similar, the clone pair is left in an inconsistent state. The set of states and changes experienced by clone pairs over time form an evolution history known as a clone genealogy. In this thesis, we provide a formal definition of clone genealogies, and perform two case studies to examine clone genealogies. In the first study, we examine clone genealogies to identify fault-prone “patterns” of states and changes. We also build prediction models using clone metrics from one snapshot and compare them to models that include historical evolutionary information about code clones. We examine three long-lived software systems and identify clones using Simian and CCFinder clone detection tools. The results show that there is a relationship between the size of the clone and the time interval between changes and fault-proneness of a clone pair. Additionally, we show that adding evolutionary information increases the precision, recall, and F-Measure of fault prediction models by up to 26%. In our second study, we define 8 types of late propagation and compare them to other forms of clone evolution. Our results not only verify that late propagation is more harmful to software systems, but also establish that some specific cases of late propagations are more harmful than others. Specifically, two cases are most risky: (1) when a clone experiences inconsistent changes and then a re-synchronizing change without any modification to the other clone in a clone pair; and (2) when two clones undergo an inconsistent modification followed by a re-synchronizing change that modifies both the clones in a clone pair.

abstract: M.A.Sc.


title: Measuring Interestingness of Documents Using Variability

contributor:
Skillicorn, B. David
Computing

subject:
Document Ranking
Interestingness

abstract: Thesis (Master, Computing) -- Queen's University, 2012-01-31 15:28:04.177

abstract:
The amount of data we are dealing with is being generated at an astronomical pace. With the rapid technological advances in the field of data storage techniques, storing and transmitting copious amounts of data has become very easy and hassle-free. However, exploring those abundant data and finding the interesting ones has always been a huge integral challenge and cumbersome process to people in all industrial sectors. A model to rank data by interest will help in saving the time spent on the large amount of data. In this research we concentrate specifically on ranking the text documents in corpora according to ``interestingness''

We design a state-of-the-art empirical model to rank documents according to ``interestingness''. The model is cost-efficient, fast and automated to an extent which requires minimal human intervention. We identify different categories of documents based on the word-usage pattern which in turn classifies them as being interesting, mundane or anomalous documents. The model is a novel approach which does not depend on the semantics of the words used in the document but is based on the repetition of words and rate of introduction of new words in the document. The model is a generic design which can be applied to a document corpus of any size from any domain. The model can be used to rank new documents introduced into the corpus. We formulate a couple of normalization techniques which can be used to neutralize the impact of variable document length.

We use three approaches, namely dictionary-based data compression, analysis of the rate of new word occurrences and Singular Value Decomposition (SVD). To test the model we use a variety of corpora namely: US Diplomatic Cable releases by Wikileaks, US Presidents State of Union Addresses, Open American National Corpus and 20 Newsgroups articles. The techniques have various pre-processing steps which are totally automated. We compare the results of the three techniques and examine the level of  agreement between pair of techniques using a statistical method called the Jaccard coefficient. This approach can also be used to detect the unusual and anomalous documents within the corpus.

The results also contradict the assumptions made by Simon and Yule in deriving an equation for a general text generation model.

abstract: M.Sc.


title: Micro-Computed Tomography Reconstruction and Analysis of the Porous Transport Layer in Polymer Electrolyte Membrane Fuel Cells

contributor:
Pharoah, Jon G.
Mechanical and Materials Engineering

subject:
Micro CT
Porous media
Polymer electrolyte membrane fuel cell
Effective properties
Micro computed tomography
X-ray
Porous transport layer

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-02-02 15:46:29.395

abstract:
A procedure is presented to analyze select geometric and effective properties of the porous transport layer (PTL) of the polymer electrolyte membrane fuel cell (PEMFC) in com- pressed and uncompressed states using micro-computed X-ray tomography (Micro CT). A method of compression using a novel device design was employed to mimic the non-homogeneous compression conditions found in functioning fuel cells. The process also features open source image processing and CFD analysis through the use of software packages Fiji and OpenFOAM (proprietary software is also used such as Matlab). Tomographic images of a PTL sample in different compressive states are first analyzed by measuring local porosity values in the through-plane and both in- plane directions. The objective of this study was to develop a method for imaging the PTL structure to show directionality within its properties using relatively inexpensive and non-destructional means. Three different PTL types were tested, one without any additives, one with Polytetrafluoroethylene (PTFE) and one with PTFE and a microporous layer (MPL). Non-homogeneous porosity was shown to exist with the highest and least variable porosity values obtained from the in-plane direction that was in-line with the direction of fibres. Porosity values compared well with values obtained from the literature. The profile of the PTL with MPL added was unattainable using this procedure as the resolution of the Micro CT was too low to resolve its pore space.
The next stage involved the effective properties analysis which included effective electronic conductivity and effective diffusivity. It was found that the through-plane values for the effective electronic conductivity study were higher than expected. The ratio between through-plane and in-plane was found to be much higher than expected from literature. Lack of sufficient resolution of fibre contacts has been shown to play a role in this discrepancy. These contact problems were shown not too affect measurements of diffusivity in the pore phase. The in-plane direction parallel to the direction of fibres was found to have the highest values of effective transport properties. Effective diffusivity ratios of between 0.1 and 0.37 were found to be reasonable with the limited experimental evidence found in literature. The it was found that the Bruggeman relation for calculating diffusivity and percolation theory by Tomadakis and Sotirchos over predicted the values for diffusion within the PTL and it is suggested that these theories are not suitable for predicting diffusivity for this material.

abstract: M.A.Sc.


title: Impact of Peer-Supported Video Analysis of Classroom Interactions on Teacher Understanding of Those Interactions

contributor:
Roulet, Geoffrey
Egnatoff, William
Education

subject: Teacher Understanding of Classroom Interactions

subject: Video-Mediated Professional Development

abstract: Thesis (Master, Education) -- Queen's University, 2012-01-31 16:50:24.598

abstract:
This qualitative case study examined a researcher-designed professional development intervention focused on improving teachers’ understanding of the interactions among students and between students and teachers in the teachers’ own classrooms. Participating teachers collaborated with the researcher in determining what they would observe and collaborated with each other in making sense of what they saw. The study analyzed participants’ discourse to characterize what they saw, how they worked together, what they found helpful in the intervention, and how they benefited.
The study took place over a three-month period at a Canadian Community College in Qatar committed to guiding its faculty in adopting a learner-centred approach. Four participants worked in pairs to share and discuss video of their own classes in action as they sought to adopt the desired learner-centred approach. After a Group Training Session led by the researcher to develop a Video Analysis Framework, the pairs worked through two iterations of individual video recording and selection of a ten-minute clip for sharing, followed by paired analysis of the clips. The researcher recorded the training session, the paired discussions, interviews, and focus group discussion. Data from transcriptions and researcher field notes were analyzed inductively and connected closely with findings from the literature on the benefits of video analysis in enhancing the effectiveness of teacher-directed professional development.
Faculty participants benefited from the intervention in a variety of ways. Production, selection, and discussion of video of participants' own class sessions drew participants into focused reflection on student interactions, which led to heightened awareness of phenomena important to participants in becoming learner-centred teachers. Sharing perspectives with their peers generated consensus in interpretation. Iterations led to higher levels of inference and the emergence of a problem-solving approach in making sense of phenomena. Motivated by video analysis, participants experimented with what they considered to be improved teaching techniques. Participants demonstrated significant risk-taking, enhanced peer professional relationships, and ownership and autonomy in professional development.

abstract: M.Ed.


title: Belief Propagation Decoding of Finite-Length Polar Codes

contributor:
Yousefi, Shahram
Electrical and Computer Engineering

subject:
Successive Cncellation
Channel Polarization
Polar codes
Information Theory
Decoding Complexity
Belief Propagation

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2012-01-31 17:10:59.955

abstract:
Polar codes, recently invented by Arikan, are the first class of codes known to achieve the symmetric capacity for a large class of channels. The symmetric capacity is the highest achievable rate subject to using the binary input letters of the channel with equal probability. Polar code construction is based on a phenomenon called channel polarization. The encoding as well as the decoding operation of polar codes can be implemented with O(N logN) complexity, where N is the blocklength of the code.
In this work, we study the factor graph representation of finite-length polar codes and their effect on the belief propagation (BP) decoding process over Binary Erasure Channel (BEC). Particularly, we study the parity-check-based (H-Based) as well as the generator based (G-based) factor graphs of polar codes. As these factor graphs are not unique for a code, we study and compare the performance of Belief Propagation (BP) decoders on number of well-known graphs. Error rates and complexities are reported for a number of cases. Comparisons are also made with the Successive Cancellation (SC) decoder.
High errors are related to the so-called stopping sets of the underlying graphs. we discuss the pros and cons of BP decoder over SC decoder for various code lengths.

abstract: I have't submitted my paper, based on the cintent of the thesis, yet; so I prefer it to be restricted until I submit my paper

abstract: M.A.Sc.


title: Glacial Dispersal of Indicator Minerals from the Izok Lake Zn-Cu-Pb-Ag VMS Deposit, Nunavut, Canada

subject:
Geology
Indicator Minerals
Till Geochemistry
Gahnite

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-01-31 18:24:19.909

abstract:
Volcanogenic massive sulphide (VMS) deposits have a characteristic geochemical suite of enriched metals, mineralization and related hydrothermal alteration minerals; however, very little research has been carried out to determine which of these minerals may be useful for exploration in glaciated terrains and there are very few case studies in the public realm that document down-ice dispersal of these from known volcanogenic massive sulphide (VMS) deposits. In response to these needs and to refine and optimize surficial exploration methods in northern Canada, this study was conducted to examine the mineralogical signature of the Izok Lake Zn-Cu-Pb-Ag VMS deposit, Nunavut and its glacial till dispersal.
Glacial sediments were deposited in the Izok Lake region by the Laurentide Ice Sheet. Detailed ice flow mapping indicates four stages of ice flow (oldest to youngest): 1) southwest (255 ̊); 2) weak flow to the northwest (315 ̊); a dominant ice flow and landform trend to the west-northwest (292 ̊), and 4) northwest (318 ̊) that was only observed east of the Iznogoudh Lake area (Hicken et al., 2011).
The till geochemical signature (aqua regia digestion ICP-MS analysis) for the <0.063 mm fraction of the till matrix is defined by elevated (above the 95th percentile) contents of Zn, Cu, Pb, Fe, Ag, Cd, Bi, Hg, Se, In and Tl. These element signatures in till can be detected up to 8 km down-ice from the deposit. Till geochemical data is used to evaluate which till samples are metal-rich and may contain indicator minerals. Indicator minerals for the amphibolite metamorphic grade Izok Lake VMS deposit includes: gahnite, staurolite, axinite, chalcopyrite, sphalerite and pyrite. Sulphide minerals are present at lower abundances than gahnite and staurolite as they are not physically and chemically as robust/resistant during postglacial weathering. Gahnite is the most useful VMS indicator mineral in the postglaciated Izok Lake area, as it was readily identified in till heavy mineral concentrates, it is abundant (100 of grains), its chemically stable in the surficial weathering environment, and can be detected up to 40 km down-ice. This study is one of the first to document indicator minerals down-ice from a VMS deposit in a postglaciated terrain.

abstract: Confidentiality agreement between the Geological Survey of Canada, Queen's University and MMG (owners of the deposit)

abstract: M.A.Sc.


title: Evolutionarily Stable Learning and Foraging Strategies

contributor:
Taylor, Peter D.
Mathematics and Statistics

subject: Evolutionary Game Theory

subject: Partially Observable Markov Decision Process

abstract: Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2012-01-31 19:55:25.11

abstract: This thesis examines a series of problems with the goal of better understanding the fundamental dilemma of whether to invest effort in obtaining information that may lead to better opportunities in the future versus exploiting immediately available opportunities. In particular this work investigates how this dilemma is affected by competition in an evolutionary setting. To achieve this requires both the use of evolutionary game theory, and Markov decision procesess or stochastic dynamic programming. This thesis grows directly out of earlier work on the Social Learning Strategies Tournament. Although I cast the problem in the biological setting of optimal foraging theory, where it fills an obvious gap, this fundamental dilemma should also be of some interest to economists, operations researchers, as well as those working in ecology, evolution and behaviour.

abstract: PhD


title: A Chemical Comparison of Two Different Oxidizing Bleaches and the History of Early European Paper and Papermaking

contributor:
Dickey, Stephanie S.
O'Neill, John
Art History

subject:
The Chemistry of Paper
Art Conservation
History of Technology
History of Paper
Art History
Papermaking
Art Conservation Science

abstract: Thesis (Master, Art History) -- Queen's University, 2012-01-31 22:51:58.027

abstract:
Background: The bleaching of paper is an important and controversial treatment employed in the conservation of art. The use of a bleach may greatly enhance the quality of an image but at a cost of lost structural integrity. In order to fully consider the ramifications of bleaching a paper artifact, a historical study of early European paper and its manufacture was conducted. The structure of paper was also studied in order to understand the finer points of early European paper manufacture and to draw conclusions from the bleaching comparison.
Results: A comparison of the commonly used ClO2 bleaching with a previously proposed chlorous acid treatment was conducted. The two different bleaching techniques were evaluated on their impact on the colour of artificially aged and unaged Whatman chromatography 1 paper. The results of the bleaching were analyzed with a colourimeter and it was determined that there was a significant change in colour as a result of the bleaching. The ClO2 and chlorous acid bleaching treatments did not produce results that were significantly different from one another, visually and statistically. The bleaching treatments were also tested with the viscometry of the paper in cadoxen and it was determined that ClO2 is a more degradative bleach than chlorous acid. The research also demonstrated that bleaching has a greater degradative impact on previously degraded samples. The quantitative results of the viscometry were accompanied by a qualitative look at the paper samples with a scanning electron microscope (SEM). In the SEM images there were slight visible differences in the samples that could correlate to aging.
Conclusions: Chlorous acid is a gentle effective bleaching technique that was as effective as ClO2 and less degrading to the paper samples. Bleaching has an increased impact on previously degraded samples, and conservators should be wary of this. Further research involving this bleaching technique is suggested. The use of an SEM in imaging damage to paper is a viable option but more work is needed with this technique to ensure conclusive results.

abstract: M.A.