title: EVIDENCE BASED MANAGEMENT: THEORY, MODEL, TEST, AND TEMPLATE

contributor:
Baba, Vishwanath
Business

subject:
Evidence-Based Management
Actionability
Systematic Review
Evidence-Based Management Collaboration

abstract: The broad purpose of this dissertation is to enhance the quality of managerial decisions through evidence-based management. Specifically, it raises three key questions: What is evidence? What are the attributes of knowledge that can facilitate informed decision making? How can such knowledge be generated? To answer these questions this thesis proposes a theory of evidence, suggesting that the strength of evidence is contingent upon its methodological fit, contextuality, transparency, replicability, and consensus. A model of evidence-based decision making is offered that explores how managers’ judgment, experience, and personal values along with the values of other stakeholders, contextual factors, and ethical constraints, may affect the decision process. Moreover, this thesis argues that in order to foster evidence-based management practice we need knowledge that is rigorous, relevant and actionable. To this end, a theory of actionability is proposed, and an empirical study is conducted to determine the attributes of actionable management knowledge. Based on the study, an actionability index is suggested. Evidence that is actionable requires sustainable collaborative effort to produce, curate and communicate. To accomplish that a theory of evidence-based collaboration is proposed. This theory conceives the collaboration as an independent organization that oversees the process of bringing rigour, relevance, and actionability together, and provides an interactive platform for producers, arbiters and users of management knowledge to communicate and collaborate. A template, guided by the theory of collaboration, is designed to produce systematic reviews that are useful for management practice.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: NURSING OVERTIME WORK IN CRITICAL CARE:  QUALITATIVE AND QUANTITATIVE PERSPECTIVES

contributor:
Ploeg, Jenny
Fisher, Anita
Akhtar-Danesh, Noori
Peachey, Gladys
Nursing

subject:
overtime
nurse
critical care
qualitative
quantitative
patient outcomes

abstract:
Background: Nursing overtime is being integrated into the normal landscape of practice to ensure optimal staffing levels and address variations in patient volume and acuity. This is particularly true in critical care where fluctuations in either are difficult to predict. Research exploring nurses’ perceptions of the outcomes of overtime has not been conducted, and studies exploring the relationship between nursing overtime and patient outcomes have produced conflicting results.
Objectives: This study aims to explore critical care nurses’ perceptions of the outcomes of overtime, their reasons for working or not working it, and to determine the relationship between critical care nursing overtime and specific nurse (sick time) and patient (infections/mortality) outcomes.
Methods: This thesis is comprised of two discrete components.  Thorne’s interpretive description guided the qualitative component and multilevel regression models tested relationships in the quantitative portion. Qualitative and quantitative methods were selected because of their complementarity and ability to explore both perceptions of overtime in addition to the relationship between nursing overtime and outcomes for nursing staff and their patients.
Results: Participants’ reasons for working overtime included: (a) financial gain, (b) helping and being with colleagues, (c) continuity for nurses and patients, and (d) accelerated career development. Their reasons for not working overtime were: (a) tired and tired of being there, (b) established plans, and (c) not enough notice. Major themes highlighting the perceived outcomes of overtime included: (a) physical effects, (b) impact on patient centered care, (c) the issue of respect, (d) balancing family and work, (e) the issue of guilt, (f) financial gain, and (g) safety is jeopardized. Regression analysis revealed that for every 10 hours of nursing overtime, sick time increased by 3.3 hours (p<0.0001). Overtime was not associated with patient outcomes (infections and mortality).
Conclusion: There are negative and positive consequences of nursing overtime for nurses and patients. Future research needs to focus on the collection of accurate patient level data, as well as tracking and exploring the effects of unpaid overtime (missed breaks/staying late). Nurses should work to proactively lobby governments to fund adequate staffing in order to reduce the need for overtime and provide safer patient care.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: This study explores critical care nurses’ perceptions of the outcomes of working overtime, their reasons for working or not working overtime, and the relationship between nursing overtime and specific nurse and patient outcomes. Qualitative and quantitative methods were used involving 28 nurses on 11 units in three tertiary care academic health science centers. The four original contributions to nursing knowledge are: (a) physical effects overtime has on nurses, (b) feelings of disrespect overtime engenders, (c) loss of patient-centered care that results from overtime, and, (d) the positive relationship between nursing overtime and nursing sick time.  Quantitative findings revealed that for every 10 hours of nursing overtime, sick time increased by 3.3 hours (p<0.0001), which participants attested to qualitatively.  It will be important to track both paid and unpaid overtime hours per individual nurse to enhance future research, ensure institutional accountability and staff well-being.


title: Experiences of Aboriginal Nursing Faculty in Canadian University Schools of Nursing: A Multiple Case Study

contributor:
Tompkins, Catherine
Nursing

subject:
Aboriginal Nursing Faculty
Institutional Racism

abstract:
Aboriginal nursing faculty have a positive impact in the recruitment and retention of Aboriginal nursing students, informing and implementing culturally responsive curricula, and engaging in research that is responsive to the needs of Aboriginal communities. Given the continued health disparities experienced by Aboriginal peoples, there is a need to recruit and retain increased numbers of Aboriginal nursing faculty. However, Aboriginal faculty have experienced racism in academia for decades. A focus on individual factors as opposed to institutional causes has resulted in little effectiveness in resolving experiences of racism. The purpose of this study was to explore the experiences of Aboriginal nursing faculty to determine if and how they experienced institutional racism.
A multiple case study approach utilizing an Institutional Racism Framework (Chesler, Lewis & Crowfoot, 2005) was undertaken. Institutional racism was identified in each of the eight cases explored. Two major findings arose from this study. First, although Aboriginal nursing faculty were expected to be the keeper of all Aboriginal knowledge, Aboriginal participants were often not viewed as ‘authentic’ Aboriginal persons at the university. The perception was that by having attained the credentials to be university faculty, the Aboriginal nursing faculty were no longer considered Aboriginal enough to have an authentic voice. Second, Aboriginal nursing faculty experience ‘walking between two worlds’. They felt that they did not fully belong in their home communities. They also identified that they did not feel that they completely belong, or were supported in the university. Rather than identifying as ‘bicultural’, Aboriginal nursing faculty clearly articulated inhabiting this new space situated between cultures.
The identification of institutional elements that address or perpetuate institutional racism allowed for recommendations to be determined. The shift from an individual to an institutional perspective allows for an alternative approach to reducing racism experienced by Aboriginal nursing faculty.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Observations on Some Arctic Soils of Southwest Devon Island, N. W. T., Canada

contributor:
Bunting, B. T.
Science

subject:
Arctic soils
Southwest Devon Island
North West Territories
chemical weathering
terrain map
relief unit

abstract: Scope and contents: An investigation into some arctic soils located on Southwest Devon Island. Some aspects of chemical weathering in the area are considered and detailed studies of patterned ground are undertaken. A terrain map was compiled to locate the major areas of soils and mineral and organic covers and to show this relationship to relief units.

abstract: No abstract provided.

abstract: Thesis

abstract: Master of Science (MSc)


title: Ternary Fission Studies of 235U

contributor:
Clarke, W. B.
Physics

subject: ternary, fission, inert gases, radioactive, nuclides

abstract:
 Part I describes experiments carried out to search for possible products of ternary fission of 235U. Inert gases extracted from neutron-irradiated 235u were analyzed mass-spectrometrically for the presence of stable and radioactive neon and argon isotopes. No evidence for fission product neon or argon was found. Upper limits obtained for the yields are orders of magnitude lower than those suggested by some other studies.

 Part II describes measurements of relative yields and energy distributions of 3H, 3He, and 4He produced in fission of 235U. A short-range (<8 Mev) component in 4He, not previously established, has been detected in this work. The upper limit obtained for direct formation of 3He is lower by two to four orders of magnitude than the frequency of formation of 3He found in studies of other fissile nuclides.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Computer Assisted Part-Programming Facilities For Numerically Controlled Machine Tools

contributor:
de Malherbe, M. C.
Production Engineering

subject:
Programming
numerically controlled machine
computer assisted
machine tools
part-programming
kinematic data

abstract:
Abstract not provided.
Thesis
Master of Engineering (ME)


title: A Statistical Analysis of Hydrocyclone Parameters

contributor:
Woods, D. R.
Chemical Engineering

subject:
hydrocyclone
feed concentration
volume split
feed flow rate
separation efficiency
energy loss
waste water treatment
statistical analysis

abstract: Both Part I and Part II are included.

abstract: The separation of a mixture of glass spheres in water using 2 inch hydrocyclones was studied. <p> Three operating parameters were investigated: feed concentration, volume split and feed flow rate. In addition, three design parameters were cone angle, inlet diameter, and vortex finder length. The performance criterion parameters were the efficiency with which the solids were separated from the liquid, and the energy required per unit mass flowing through the hydrocyclone. </p> <p> First the experimental data were analyzed by three different statistical methods and the results compared in an attempt to determine which statistical method was most suitable for this two criteria system. The three methods were principal component analysis, canonical correlation analysis and multiple regression analysis. The theory behind these methods is briefly outlined. Our conclusion is that using all three methods give much more insight than could be obtained from any individual method. </p> <p> Second, an analysis of the above eight hydrocyclonc parameters of hydrocyclones with cylindrical sections indicated that for the range of parameters covered in this work, feed flow rate and inlet diameter influenced the energy loss most; volume split influenced the separation efficiency the most. Energy loss and separation efficiency are quite independent; this means that it is possible to design and run a hydrocyclone with high separation efficiency and low energy loss. The dilute concentrations used in this work indicate that a hydrocyclone of conventional design can be used in waste water treatment. When the parameters were correlated, a power model gave more consistent interpretation than a linear model. </p> <p> Third, the effect of the three operating parameters on hydrocyclones with three different body shapes suggested that the most efficient cyclone was one with a straight cone and no cylindrical section. The body shape dictated which parameters would significantly affect performance. </p>

abstract: Thesis

abstract: Master of Engineering (ME)


title: An Investigation of the Feasibility of Applying Frequency Response Analysis to Study Fluid Flow Reactors

contributor:
Norman, J. D.
Chemical Engineering

subject:
fluid flow reactor
frequenc response tracer technique
flow rate
applied mixing
completely mixed segments
plug flow segments
dead space alllowances

abstract: A frequency response tracer technique was used to study the hydraulic properties of a laboratory flow through reactor with variations in reactor size, flow rate and applied mixing. At any one set of conditions the reactor was studied over a range of input sine wave frequencies. Theoretical models consisting of in-series networks of completely mixed segments, plug flow segments, and dead space allowances were developed to approximate the experimental findings.

abstract: Thesis

abstract: Master of Engineering (ME)


title: A Study of Levels Populated in 166Er by the (3He,d) Reaction

contributor:
Burke, D. G.
Physics

subject: reaction, gamma, vibrational, band, nuclear, magetic

abstract:
 The reaction 165Ho (3He,d) 166Er was studied using the University of Rochester Tandem Van de Graaff accelerator and an Enge-type split-pole magnetic spectrograph. The observed cross sections for the ground state rotational band and the gamma vibrational band were consistent with predictions based on the unified nuclear model. The population of the 1574 keV level was consistent with that expected for the K^π=4^-, 7/2-[523] + 1/2+[411] assignment obtained from decay scheme studies. The K^π=2^- octupole vibrational band based on the 1460 keV state was not populated as strongly as expected, indicating that the admixture of the
7/2-[523] - 3/2+[411] two proton state into this vibration is only about one-fifth as large as predicted by Soloviev et al.

abstract: Thesis

abstract: Master of Science (MSc)


title: Optimal Shape of a Distributed RC Notch Filter  - A Computer-Aided Design

contributor:
Campbell, C. K.
Electrical Engineering

subject: computer-aided, RC Notch, filter, dielectric, bandwidth, optimal

abstract:
 An improvement on the synthesis of a distributed RC notch filter, by computer-aided design techniques, is appraised. A brief presentation of the synthesis of thin-film RC tapered networks is made, along with applied uses of computer-aided design to RC distributed networks, particularly in the realizability of certain RC transfer functions.

 The preparation of the problem, accompanied by different methods of approach, is explained. Included are criticisms made, leading to the reasons for abandoning the more tasking ones.

 The Adjoint Network method of determining, gradients, with respect to circuit adjustable parameters, is evaluated fully, and the important use which it lends to the optimization problem is demonstrated. The outcome of the design approaches are given in tables, with theoretical responses compared in graphs. Actual circuit responses are indicated in photographs, and comparisons with theoretical responses are shown in graphs.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: An Exact Treatment of the Pauli Exclusion Principle and its Application in Nuclear Matter

contributor:
Sprung, D. W. L.
Physics

subject: nuclear, matter, Pauli exclusion principle, conventional, angular, energy

abstract:
 In second order perturbation theory for nuclear matter, an exact treatment of the Pauli exclusion principle is given from a geometrical point of view. All the kinematic effects of the Pauli exclusion principle are then included in a function K(k,k',q), which is related to the
Euler's function through a double integration. With this function K(k,k',q), we can treat the Pauli correction in nuclear matter in a more exact way so that a check to the conventional angular average approximation is obtained. For separable core nuclear potential, this function K(k,k',q) serves as a very convenient apparatus for the perturbation calculation of the binding energy in nuclear matter.

abstract: Thesis

abstract: Master of Science (MSc)


title: Statistical Treatment of Nuclear Energy Levels

contributor:
Kennett, T. J.
Physics

subject: nuclear, energy, levels, excitation, temperature

abstract: Low-lying nuclear energy levels are analyzed in terms of certain parameters of the correlation between the level spacing and the excitation energy. The statistical properties of the estimates for the parameters arising from a constant nuclear temperature model are examined. Estimates are made for the parameters for the levels of Mn^56 inferred from capture gamma spectra.

abstract: Thesis

abstract: Master of Science (MSc)


title: ENHANCING THE DISSEMINATION, ACCESS AND USE OF CURRENT BEST EVIDENCE AT THE POINT OF CARE

contributor: Clinical Health Sciences (Health Research Methodology)

subject:
Evidence-Based Medicine
Knowledge Translation
Evidence Retrieval
Shared Decision Making
Decision Aids
Clinical Practice Guidelines

abstract:
This dissertation presents a body of research consisting of 5 scientific papers with an overarching objective to develop and test interventions that can enhance the dissemination, access and use of current best evidence at the point of care. Questions constantly arise from clinicians’ interactions with their patients, but more than 60% remain unanswered. The first 4 papers therefore focused on evidence dissemination to clinicians and trainees looking for answers and trying to stay alert to new evidence. We used as our “laboratory” an online tool developed at McMaster University’s Health Information Research Unit, the MacPLUS Federated Search (MacPLUS FS), which allows busy clinicians to search multiple top high quality resources simultaneously and display a 1-page output with the most clinically useful results at the top. Guided by effective models for the teaching of clinical skills at the point of care, we designed 3 web-based interventions addressing logistical and educational barriers to increase the quantity and quality of searching for current best evidence. These interventions were: (A) a web-based Clinical Questions Recorder and Reminder; (B) an Evidence Retrieval Coach composed of 8 short videos embedded in MacPLUS; (C) and a Gamified Audit & Feedback based on the allocation of “badges” and “reputation scores” for evidence searching.
We tested these interventions in 4 factorial randomized-controlled trials among 1,868 heath care professionals and students currently registered in MacPLUS FS, namely: 477 medical faculty members, 431 postgraduate medical trainees, 725 nursing students and 235 medical students. Results showed that these target populations substantially differed both in their baseline frequency of search and access to alerts, as in their responsiveness to the 3 web-based interventions on evidence utilization.
Evidence summaries have traditionally been tailored to meet the educational needs of clinicians, but are seldom provided in a format that supports shared decision-making. Our fifth paper explored a potential solution, which constitutes another route for evidence dissemination and use. In a project called SHARE-IT, we developed a new framework and online prototype for the generic production of decision aids, which allow physicians and patients to discuss the evidence together in the clinical encounter. We present the framework, design methods and early testing of this generic approach, which showed promising results for the translation of evidence summaries into useful tools for shared decision-making.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: POWER, PRIVILEGE, AND PATRIARCHY

title: POWER, PRIVILEGE, AND PATRIARCHY: THE COMPLEXITIES THAT ARISE FOR WOMEN ENDURING DOMESTIC VIOLENCE AROUND ACCESSIBILITY TO SERVICES IN TRINIDAD AND TOBAGO

contributor:
Carranza, Mirna
Social Work

subject: domestic violence, colonization, women, Trinidad and Tobago

abstract:
Domestic violence is a complex crime against humanity that has been socially constructed over time by a patriarchal system that has encouraged an imbalance of power relationships between men and women for centuries (Dupont & Sokoloff, 2005, p. 42-43).  The objective of this thesis is to create further dialogue based on the pioneering work of Danns and Parsad’s (1989) research in exploring the role colonization plays in shaping domestic violence in the Caribbean.  As a result, this research identified gaps in knowledge around women’s reluctance to report incidents of domestic violence, a tendency to rationalize men’s violence and at some level male violence is tolerated, as well how colonization altered the national identities and ethnicities of  Caribbean people.
The concepts presented throughout this thesis were informed through social constructionism, where certain ideologies have created psychological or ‘internal’ divisions around ethnicity, region, and gender (Brereton, 2010).  Over time, Danns and Parsad (1989) argue that the implications of colonization have created issues of insecurities, frustration, and ego by means of social norms which emphasize a male machismo.  Danns and Parsad (1989)’s study also refers to the impact of colonization as a root of domestic violence and how Caribbean history reproduces male dominance.  As a result, violence against women and domestic violence is based on gender inequality and female subordination, which has transcended through colonization.  Further, women’s vulnerability is reinforced by the lack of economic opportunity and the power of authorities to dismiss or minimize women’s issues (p. 23).  This has led me to think about the history of Trinidad and Tobago, domestic violence, and how this has impacted on women.  In addition, I asked if such policies and legislation as the Domestic Violence Act (1991) support organizations in their role to help and assist women from violence then why is violence against women not decreasing in Trinidad and Tobago?
To  explore these ideas and the impact domestic violence has had on Caribbean women, I engaged in a qualitative research study over a six-week period on the islands of Trinidad and Tobago.  This research focused on two major questions: (a) what are some of the contributing factors that sustain domestic violence in Trinidad and Tobago and (b)  how do organizations respond to the demands of women enduring domestic violence.  The research engaged a feminist and a critical theoretical approach, eliciting stories from 10 women.  From these stories, a number of themes emerged which included:  1) ‘visible’ yet ‘invisible’; 2) ‘light skin’/’dark skin’; 3) ‘private matters’; 4) re-victimization of women by the system; and 5) an overarching theme of ‘power’ and ‘control’.  As a result, women shared that domestic violence and the history of colonization play a role in keeping women in subordinate positions in three disadvantaged dimensions: reproductive health, empowerment, and the labour market.  Yet, this research also speaks to potential ways in which  men and women can find common ground through the deconstruction of the history and colonial legacy of violence (Cruz et al., 2011; Murdoch, 2009).  The research also points to ways for the unequal distribution of power to be minimized in both the public and private spheres, and ways to understand the impact of domestic violence and the possibility of ending it in the future.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: EXPLORING SERVICE PROVIDERS’ PERSPECTIVES ON MENTAL HEALTH- MUSLIM UNIVERSITY STUDENTS

subject:
Muslim
Mental Health
University students
Social Work

abstract:
This study examines the perspectives of seven mental health professionals who work with Muslim university students. The study specifically examines the experiences, struggles, and needs of Muslim university students in accessing mental health services from the perspective of mental health providers. Additionally, this study presents recommendations for service providers to consider when working with Muslim university students. It has been observed that almost all theories and data related to contemporary psychology have come from Western populations (Basit & Hamid, 2010). Hence this study attempts to fill a void in current knowledge.
	A qualitative research study (Mason, 2000) utilizing a critical social science approach as well as principles related to Grounded Theory were applied to this study. Individual interviews were carried out with seven participants. The data analysis revealed various themes: understandings of well-being, factors impacting Muslim students’ well being, existing needs, and a proposed model when working with Muslim Students. The paper concludes with a brief set of recommendations for practice and limitations.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: The Politics of Christian Forgiveness: An Augustinian Assessment of Hannah Arendt

contributor:
Kroeker, Travis
Religious Studies

subject: forgiveness politics

abstract:
This thesis argues that Augustine’s account of Christian neighbour love properly characterizes and illuminates the political relevance of forgiveness within Christian community. The Christian commitment to love the neighbour is offensive to Hannah Arendt’s conceptualization of political freedom and political action, yet Augustine challenges Arendt’s notion of Christian ‘otherworldliness’ by locating the source of authentic forgiveness and political identity within the divine kenotic love of Christ. For Arendt, political forgiveness has the capacity to release us from the unforeseen and potentially devastating consequences of action as it safeguards our political interrelatedness and distinct human individuality.  Arendt’s central objection to Augustinian forgiveness concerns its rootedness in Christ’s divine love, which, Arendt argues, destroys the public realm in which human political freedom rests.  However, an Augustinian theological imagination responds to Arendt’s critical account of love by showing how the Incarnation is the exemplar of human political interaction.  For Augustine, Christ as neighbour – in his divinity and humanity - makes forgiveness comprehensible as a politically relevant enactment of restorative love, and the worldly life of Christian community witnesses to this enactment as it points to coming fullness of God’s kingdom.
Augustine offers us a way of thinking about a politic of forgiveness that tempers our expectations of political life as it broadens our understanding of love’s capacity to restore.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: The Effects of Self-Efficacy, Self-Control Strength and Normative Feedback on Exercise Performance

contributor:
Bray, Steven
Kinesiology

subject: Self-regulation, Strength Model, Control Theory, Resistance exercise, Ego Depletion, Endurance exercise, Subjective fatigue, Self-efficacy theory

abstract:
The strength model of self-control suggests that self-regulation and self-control processes are governed by finite internal energy resources.  However, this perspective has recently come under scrutiny suggesting that self-control processes are not solely constrained to limited resources and may also be guided by motivational-cognitive processing.  Self-efficacy theory and control theory are two theoretical views of self-regulation that also suggest self-regulation failures are dependent on motivational-cognitive processes; however the potential role of limited resources has not been evaluated in the context of these theoretical views. This dissertation sought to advance our understanding of self-regulation and self-control of exercise behaviour by integrating the three theoretical perspectives discussed above.
       Study 1 showed that self-control depletion leads to reductions in task self-efficacy mediating the self-control depletion – negative performance change relationship.  Overall, findings are consistent with self-efficacy theory.  However the results are limited as the mechanism(s) leading to reduced self-efficacy following self-control depletion remain unclear.
	Study 2 explored a sequential (serial) mediation model investigating the idea that exerting self-control leads to an altered psychophysiological state increasing subjective fatigue, which in turn, leads to reduced self-efficacy to exert self-control and reductions in physical self-control performance.  Findings supported the proposed sequential mediation model.  However, it remains unclear to what extent that self-efficacy plays a passive or active role guiding self-controlled behaviour following self-control depletion.
	Study 3 explored the independent and interactive effects of self-control depletion and normative performance feedback on self-efficacy and physical self-control.  Findings showed an interaction between self-control depletion and feedback.  Findings support predictions of control theory when self-control resources are intact, but suggest feedback information is processed differently when self-control strength is depleted.  Overall, results show that when self-efficacy is manipulated by feedback the effects of self-control depletion on performance are no longer evident supporting self-efficacy’s role as an active causal mechanism determining behaviour.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Self-control failures are at the heart of many societal problems. A dominant theoretical view suggests self-control is governed by a limited internal resource.  However, this perspective has recently been opposed by theorizing and evidence suggesting that people experience self-control failures due to shifts in motivational-cognitive processes.  This thesis integrated three theories of self-control (i.e., strength model of self-control, control theory, and self-efficacy theory) in an attempt to provide a more complete understanding of why self-control failures occur for people performing demanding physical exercise.  Findings suggest that each theoretical perspective provides complementary explanations for why self-control failures occur and how they can be overcome through shifts in cognitive processing.  Specifically, self-control exertion leads to subjective fatigue, which decreases self-efficacy to exert self-control, and in turn reduces self-control performance.  Furthermore, after self-control exertion, positive normative performance feedback increases self-efficacy and subsequent self-control performance whereas negative feedback drastically reduces self-efficacy and performance.


title: Experimental and Modeling Studies of Diffusion-Controlled Reactions in Atom Transfer Radical Polymerization at High Conversion

contributor:
Zhu, Shiping
Chemical Engineering

abstract:
Controlled radical polymerization (CRP), especially atom transfer radical polymerization (ATRP), has attracted great attention in the recent years. It provides a powerful tool for synthesis of functional polymers with a predetermined molecular weight and narrow molecular weight distribution (MWD). Although tremendous effort has been made in this area over the past decade, there are still many challenges that limit its industrial applications. High monomer conversion is one of the most important critical issues for commercial exploitation of CRP processes. Another important task is to eliminate organic solvents in polymerization. Most solvents are volatile organic compounds (VOCs), and are of environment and health concerns. Separating the polymer product from the solvent and removal of residual monomer are both energy intensive and costly. This thesis focused on the study of bulk ATRP at high conversion experimentally and through performing modeling. The main objectives are to elucidate the mechanism of ATRP at high conversion and to develop strategies for reaching high conversion in bulk while maintaining livingness and control of the polymerization. This sandwich-type thesis is organized based on five refereed-journal papers first-authored by the candidate.
Methyl methacrylate (MMA) was polymerized in bulk via atom transfer radical polymerization (ATRP) using initiator for continues activator regeneration (ICAR) method. “Gel effect” started at medium conversion and it was accompanied with molecular weight distribution broadening. A dramatic increase in polydispersity was observed at high conversion. The loss of control over molecular weight was attributed to diffusion-controlled deactivation.
Model simulation of bulk ATRP revealed that it is diffusion-controlled deactivation that causes auto-acceleration in the rate (“gel effect”) and loss of the control. At high conversion, radical chains are “trapped” because of high molecular weight and high viscosity. However, the migration of radical centers through propagation (residual deactivation) can still facilitate catalytic deactivation of radicals, which improves the control of polymer molecular weight to some extent.
It was found that ICAR agents could significantly affect the rate of catalyst regeneration and consequently the rate and control of polymerization. By optimizing the ICAR agent concentration and employing step temperature profile, MMA was polymerized with ppm concentration of catalyst up to very high conversion with good livingness and control. Furthermore, it was demonstrated that employing ultrasonic waves could be helpful in order to keep the control and livingness up to high conversion through improving homogeneity of the polymerization medium and diffusivity of the reactants during the polymerization, especially after the onset of diffusion-controlled deactivation.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Nowadays, polymeric materials are being used in different areas of industry and our daily life. There are different polymerization methods for producing polymers. One of the newest methods, is controlled radical polymerization (CRP), especially atom transfer radical polymerization (ATRP). Although there is about two decades of intensive study about ATRP, its significant industrial applications are still lacking. Limited monomer conversion is one of the most challenging problems in this area. In this project, the problem of reaching high monomer conversion in ATRP was studied experimentally and through performing modeling. Different strategies such as adjusting concentration of the reactants, employing a step temperature profile and using sonication waves were then investigated as the helpful methods for overcoming the problem.


title: Interfacial Area Measurement Using a Radioisotope Technique

contributor:
Banerjee, S.
Engineering Physics

subject: interfacial, radioisotope, technique, phases, solution, concentration, scintillation

abstract: This is Part A of the Thesis. The link to Part B is here:

abstract:
 A radioactive technique to determine interfacial area between solid-liquid and liquid-liquid phases has been investigated. Plastic and liquid scintillators and β-particles from tritium solution were used for this purpose.

 The tritium β-particles have a very short range (about 5 μm in water), and the surface area of contact between the tritium bearing fluid and the scintillator bearing phase is expected to be proportional to the scintillation count rate, which in turn is proportional to the number of betas crossing the interface from a very thin region.

 To test this hypothesis, two phases were placed together in a cylindrical plexiglas container, which in turn was placed in an aluminum light-tight housing. The housing also enclosed the photo-multiplier tube (PMT). Pulses corresponding to scintillations due to β absorption were taken from the PMT and fed to a suitable electronic circuit. The count rate was obtained with a multi-channel analyser.

 It was found that the count rate is a linear function of interfacial area between the tritium bearing fluid and the scintillating material. Some deviation from linearity was however noticed at very low tritium concentration. The count rate remained the same for a given interfacial area regardless of orientation of the surface(s) with respect to the photocathode face.

 This appeared to confirm the hypothesis that interfacial area could be measured in systems of this type by measuring the scintillation count rate.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Steady State Response of a Non-linear Mechanical System Provided with an Impact Vibration Absorber

contributor:
Dokainish, M. A.
Mechanical Engineering

subject: investigation, non-linear, vibration, absorber, bi-linear

abstract:
An investigation of the steady state response of a non-linear system provided with an impact vibration absorber is made. The term non-linear in the present case refers to a system in which the spring restoring force is bi-linear./p>
 The effect of two main parameters viz. clearance d o (i.e. the free path of travel of the mass particle) and mass ratio μ = m/M (i.e. mass ratio between the mass particle and the primary system) on amplitude of vibration of the system has been investigated experimentally over a range of frequency.

A numerical analysis of the problem is made with the aid of a digital computer to supplement the experimental results.

 It has been found that with proper choice of parameters an impact vibration absorber is effective in reducing vibration level of a nonlinear
system undergoing sinusoidal excitation.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Aircraft and Satellite Remote Sensing for Biophysical Analysis at Pen Island, Northwestern Ontario

contributor:
Howarth, P. J.
Geography

subject:
aircraft
satellite
remote sensing
biophysical mapping
Pen Island
LANDSAT satellite data
airphoto
Northwestern Ontario

abstract: The capabilities of a number of remote-sensing techniques for biophysical mapping in the subarctic have been examined at Pen Island in northwestern Ontario. After a two week field reconnaissance, colour infrared aerial photography was studied and a detailed biophysical map of the area was produced. Using this knowledge LANDSAT satellite data of the site were investigated. In a visual analysis of the data, the majority of the units identified in the airphoto interpretation were detected, and these were distinguished primarily by their spectral characteristics. Digital analysis of the satellite data using the Bendix MAD system allowed many of the classes of the earlier studies to be delineated and also permitted the classification to be readily extended beyond the original site. In both LANDSAT analyses specific biophysical units could be mapped from the satellite data but could not be identified without the airphoto interpretation.

abstract: Thesis

abstract: Master of Science (MSc)


title: New Design of Hot Strip Mill Runout Table

contributor:
Siddall, J. N.
Mechanical Engineering

subject:
hot strip
runout table
air cushion
cooling
Hot Strip Mill

abstract: The work presented herein describes the production of hot strip with special attention to the runout table. Because of its high capital and operating costs, a new principle in conveying the strip using an air cushion and a new cooling system for strip cooling have been proposed. Information given here is nearly all from available literature and the author's own experience with Hot Strip Mill production problems. To support the idea of using an air cushion for strip conveying, experimental equipment was designed and built which confirmed the feasibility of the method. A new cooling system was also proposed to meet the ever increasing requirements for better mechanical properties of hot strip. Runout table design application may serve as a guideline in designing new Hot Strip Mill runout table.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Thornhill to Richmond Hill

subject:
Thornhill
Richmond Hill
geography
topography

abstract:
No abstract provided.
Thesis
Bachelor of Arts (BA)


title: The Spatial Distribution of Fruit Varieties in the Fonthill Area

contributor:
Reeds, L. G.
Geography

subject:
Fonthill
fruit distribution
Pelham township
farming
land-use

abstract: From the Introduction: "The distribution of fruit in the Fonthill area will be examined and an explanation attempted in terms of the physical environment, economic condition and other criteria affecting the farmers' land-use decision."

abstract: An abstract is not provided.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: An Application of the Nearest Neighbour Technique: Patterns of Urban Places in Southern Saskatchewan

contributor:
Potvin, J. G. C.
Geography

subject:
nearest neighbour technique
settlement pattern
urban areas
Saskatchewan
Central Place Theory
multivariate analysis

abstract: The patterns of certain groups of urban places, selected on the basis of population size and area location, in southern Saskatchewan are classified by the use of the nearest neighbour technique. Through a study of the variations within the overall pattern, which are revealed by differences in the derived pattern statistic, a partial contribution is made to the understanding of the distributive process that underlies the observed settlement pattern. Explanations for the variations in the nature of the spatial arrangement of the various groups of places are suggested through the use of multivariate analysis, and by reference to theoretical and empirical works in the field of Central Place Theory.

abstract: Thesis

abstract: Master of Arts (MA)


title: Stochastic Development of Dissolution Morphology

contributor:
Ives, M. B.
Metallurgical Engineering

subject:
dissolution
dissolution morphology
crystal
simple cubic crystal
Terrace-Ledge-Kink model
pit shapes

abstract: In order to investigate the formation of different types of pit shapes on the crystalline surfaces, a mathematical model has been considered, which does not take into account surface diffusion and which defines the removal or transformation of different characteristic sites on the surface according to a set of frequencies. The characteristic sites are defined according to Terrace-Ledge-Kink model for the simple cubic crystal. With the help of the geometry of the step systems, specific conditions have been obtained under which the step systems considered could be obtained for a pit of monoatomic thickness. The dissolution of a simple cubic crystal has been simulated according to a set of probabilities.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Experimental and Theoretical Studies of Phase Equilibria in the System NaAlSi3O8-NaAlSiO4-H2O with Special Emphasis on the Stability of Analcite

contributor:
Burley, B. J.
Geology

subject: phase equilibria, stability, Analcite, melts, hydrous, minerals, binary

abstract:
 Phase equilibrium relations were determined in the system NaAlSiO8-NaAlSiO4-H2O on a P-T projection in the P-T range 0.5-10Kb and 150°-900°C, and on three isobaric (2Kb, 5.15Kb and 7. 32Kb) T-X projections. The T-X stability field of analcite determined in this study has a relatively large distorted pentagonal shape. The petrogenetic problem of analcite is fully discussed. On the composition join NaAlSiO4-H2O, the phase relation is not binary for the transition: nepheline hydrate I = nepheline + H2O; there exists a narrow three-phase zone for the transition. The true P-T curve was determined in terms of a ternary univariant reaction: nepheline hydrate I+ analcite = nepheline + H2O. Another univariant reaction (zeolite species P. = analcite + nepheline hydrate I+ H2O) was found at 2Kb/215°C and
5.15Kb/235°C and determined on a P-T projection. In the system NaAlSi3O8-SiO2-H2O, albite contains a maximum of about 5 Wt.% silica in solid solution at 5.15Kb/670°C.

 The equilibrium compositions of various univariant phases were determined essentially by phase boundary-location on several isobaric T-X projections. Three singular points were determined: two of them are approximately located at 0.8Kb/390°C and 9.4Kb/475°C on a
univariant curve (N-h I+ Anl =Ne+ H2O). The other one is approximately located at 6Kb/655°C on the (Ab) univariant curve.

 A simple method for determining H2O-solubility in melts was developed and applied to the study of the system NaAlSi3O8-NaAlSiO4-H2O. Using this method, solubility data are simply obtained as by-products of the experimental runs made for the investigation of the phase equilibria. The amount of water required to make an H2O-saturated melt (from the total amount of water in the original charge) is taken as the dissolved water in the melt; the solubility value is corrected by determining the amount of moisture originally absorbed in the starting powder. The method is generally applicable to the determination of H2O-content in any hydrous phase. The H2O-solubility in a melt is not too sensitive to a variation in anhydrous composition of the melt (~ 6±1 Wt.% H2O at 2Kb and ~11±1 Wt.% H2O at ~5Kb in the range of compositions Ab100Ne0-An40Ne60). H2O-solubility in the (Anl) and (Ne) univariant melts was determined up to l0Kb (H2O contents: 4.7 Wt.%/1.1Kb and 850°C, 6.2 Wt. %/2Kb and 804°C, 10.8 Wt. %/5.2Kb and 672°C, l2.2 Wt.% /6.6Kb and 655°C, 13.2 Wt. %/7.3Kb and 652°C and 14(?)
Wt.% /10Kb and 632°C ). The origin of water bubbles in quenched hydrous glasses is essentially attributed to the exsolution of the dissolved water in melts upon quenching.

 The sequence of P-T curves around a quaternary invariant point (~5Kb and ~635°C) in the system NaAlSiO4-KAlSiO4-SiO2-H2O was theoretically discussed. The most probable four P-T diagram types are proposed, one of which is expected to be the real one.

 Phase relations in the system NaAlSi3O3-NaAlSiO4-H2O are theoretically discussed up to ~15Kb. The discussion is largely based on the equilibrium compositions of invariant phases approximately estimated from data presented in Parts 1 and 2. Six invariant points are examined. Two of them, I5 and I6, have been predicted to occur; I5 is inferred to be located at ~13Kb/~500°C where five phases Jd, N-h I, Anl, Ne and V coexist, and I6 to be located at ~0.5Kb/-375°C where Ab, Ne, Anl, N-h I and V coexist. The phase relations around the other four are partly modified. The maximum P-T stability field of analcite is deduced. The stability field of solidus analcite is extremely large whereas that of liquidus analcite is very much limited. The maximum stability field of liquidus analcite is a small triangular area defined by three invariant points I1 (5.15Kb/657°C), I2 (11Kb/650°C) and I4 (12.5Kb/575°C).

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Nuclear Potential and Nuclear Matter

contributor:
Preston, M. A.
Physics

subject: niclear, potential, matter, reference spectrum, binding energy

abstract:
The one-boson-exchange potential model is studied in some detail. The parameters of a velocity-dependent potential based on such a model are fitted to reproduce two-body
scattering data. This potential is then used in nuclear matter calculations by means of the reference spectrum method. It is shown that the average binding energy of a nucleon in
nuclear matter and the saturation density are in reasonable agreement with the experimental values.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Indium Tin Oxide Nanoparticles Formation for Organic Electronics

contributor:
Turak, Ayse
Engineering Physics

subject:
Indium Tin Oxide
Organic Electronics
Diblock copolymer
Nanoparticles

abstract: Indium tin oxide is a transparent conductive oxide electrode which is widely used for organic electronics. Morphology of ITO plays an important role in the performance of organic electronics. To understand the influence of the substrate morphology in device performance, a controllable route for producing periodic and aperiodic roughness of ITO surfaces are necessary. In this thesis, this was attempted by using various approaches to forming ITO nanostructures. Initially, ITO was deposited by a traditional sputtering procedure. However, the roughness distribution of the sputtered ITO resulted in a s Gaussian distribution, unsuitable to further studies of roughness. ITO nanostructures can also be formed by depositing ITO nanoparticles on an ITO sub- strates. Using acetate and chloride precursors, ITO films were produced from solution and formed into nanoparticles using the reverse micelles deposition approach. The acetate route (InAc+SnCl2+ethanol), was the most successful prior to the nanoparticle formation, showing high quality ITO with bixbyte crystal structure and Sn percentages of 20%, low enough to form a conductive film. Nanoparticles were fabricated with diblock copolymer reverse micelles(PS-b-P2VP). Reverse micelles were found to act as a nano reactor, restricting the size of nanoparticles by having hydrophilic reactants undergo chemical reactions inside the micelles. However, nanoparticles from the reverse micelles revealed Sn percentages much above 20%. This was attributed to the solubility difference of the precursors leading to displacing or preventing of pre- cursor loading into the reverse micelles. The change of the stirring time, the micelles concentration, the sequence of precursors loading, and the weight of precursors were not found to affect the Sn concentration; moreover, large variations in Sn concentrations were observed. From quantitative nano mechanical testing of the micelles, a maximum load amount for the precursors was observed, confirming that the high concentration of Sn was likely due to the solubility differences between the precursors and their ability to penetrate the micelle. By manipulating the nanoparticles distribution through spin coating speeds, micelles concentration, and deposited volume, several degrees of order were obtained, though hexagonal packing was not observed. In general, even though Sn concentration were found to be above 20%, nanoparticles were successfully fabricated with reverse micelles, confirming that the reverse micelle technique is a good strategy for future studies of roughness.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Humane Trap Evaluation

contributor:
Kardos, G.
Mechanical Engineering

subject: humane, trap, impact energy, clamping force, scales

abstract:
 A set of scales was created, the "Modified Conibear Scales" which can be used as a basis of comparison to rate the performance of other traps in the areas of impact energy, closing time and clamping force. Further, a detailed set of secondary non quantitative characteristics was presented.

 Using the above information, several promising traps were rated in order to assess these scales, give some immediate results and indicate promising traps or trap features. Further work in the field was facilitated by providing a detailed experimental procedure, complete lists of data and a calibrated trap for animal research.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Investigation of Mg and Sr Distribution in Speleothem

contributor:
Schwarcz, Henry P.
Geology

subject: speleothem, concentrations, formation, mechanism, temperature, partitioning

abstract:
 The distribution of Mg and Sr in speleothem from Yorkshire, England, Vancouver Island and West Virginia, was investigated. Concentrations of Mg range from 300 to greater than 3000 parts per million. Concentrations of Sr range from less than 100 to a few hundred parts per million. Sr partitioning between seepage water and calcite may be more rate sensitive than Mg partitioning.

 It is possible that Mg and Sr in speleothem could provide information on kinetics and mechanism of speleothem formation and on seepage water and source rock composition.

 It may be possible to interpret Mg concentration in speleothem in terms of temperature if equilibrium partitioning of Mg between calcite and seepage waters can be demonstrated.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Development of novel chimeric receptors for delivery of costimulation to tumor-reactive engineered T cells

title: Chimeric receptors for delivery of T cell costimulation

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject:
Immunology
T cell
Cancer
Immunotherapy

abstract:
Introduction: Manipulation of the immune system to eliminate cancer, known as cancer immunotherapy, is an emerging field that has shown impressive clinical success and promise. Adoptive transfer of T cells engineered for tumor reactivity is an avenue of therapy for patients with previously untreatable disease. Our lab has developed a novel chimeric receptor, called a T cell antigen coupler (TAC), which redirects T cell cytotoxicity towards a tumor target. Although considerably effective, this receptor does not provide T cell costimulation necessary for optimal anti-tumor effectiveness.
Methods: We explored two methods to deliver costimulation to TAC-engineered T cells. First, we designed a receptor to be utilized in conjunction with the TAC in a dual receptor system. This chimeric costimulatory receptor (CCR) was generated by fusion of the T cell TIGIT and CD28 receptors. In our second approach, we investigated direct incorporation of costimulatory domains into the TAC design. To do so, we substituted in regions from the CD28 or 4-1BB costimulatory receptors.
Results: Three TIGIT/CD28 chimeras were successfully generated. Of these, two were well surface-expressed on primary human T cells. Despite testing of these receptors in several biological assays, we were unable to confirm functionality of these receptors in transmitting CD28 signals. We next generated the 4-1BB and CD28TAC variants. The 4-1BBTAC was poorly surface-expressed
M.Sc Thesis – Arya Afsahi McMaster University – Medical Sciences
iv
and was difficult to introduce into T cells at high efficiency. The CD28TAC-variant was virtually absent from the T cell surface membrane. Further analysis indicated that the CD28TAC was retained in the endoplasmic reticulum (ER) and the 4-1BBTAC was produced at an extremely low amount.
Conclusions: Our investigation into delivery of costimulation through a novel CCR or TAC receptor was inconclusive. We recommend several optimizations to both receptor design and experimental analysis to further elucidate the potential of these receptors.

abstract: Thesis

abstract: Master of Science (MSc)


title: LOCAL ANESTHETIC INJECTIONS WITH OR WITHOUT STEROID FOR CHRONIC NON-CANCER PAIN: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

contributor:
Thabane, Lehana
Health Research Methodology

subject: local anesthetic; steroids; chronic pain; non-cancer pain; epidural injections; steroid injections; nerve blocks

abstract: The primary focus of this thesis is to establish the clinical utility of corticosteroid injections mixed with local anesthetics, when compared to only local anesthetics, for relief of pain in patients with chronic non-cancer pain. Chronic non-cancer pain is common and causes significant pain and suffering to patients, and economic burden to health care system. Injection of steroids is an option, either by targeting the painful structure or the associated neural elements. Steroids are commonly mixed with local anesthetics in the hope of prolonging the pain relief. Since there is no evident inflammation in most chronic pain conditions, and because existing clinical studies do not consistently support its effectiveness in various clinical conditions, the potential value of adding steroids is questionable. This clinical question has been addressed through a comprehensive systematic review and meta-analysis of randomized control trials comparing injections of steroid with local anesthetics against only local anesthetics for chronic non-cancer pain conditions.  Our review found that there is paucity of good quality randomized controlled studies specifically addressing this comparison. Although a large numbers of studies were identified, there was a small effect favoring steroids in studies measuring pain relief by dichotomous outcomes. Overall confidence in the effect estimates were limited due to serious concerns of bias, significant heterogeneity and variability in studies, leading to low quality. A majority of the included studies did not aim to capture the full spectrum of adverse effects. Future studies addressing this clinical question should aim to be of optimum size, must aim to limit the threat of bias, and capture all patient important outcomes including pain relief.

abstract: Thesis

abstract: Master of Science (MSc)


title: Morphological Variations in Jack Pine (Pinus Banksiana) Along its' Central to Northern Population Ranges

contributor:
MacDonald, G.
Geography

subject: morphological, population, jack pine, Mackenzie River, latitudinal, transect

abstract: The analysis of six jack pine populations along a north-south transect through the MacKenzie River Valley in the Northwest Territories revealed no significant latitudinal trends in cone and seed morphometric measurements. In attempting to determine whether any variations may be environmentally induced, Radial Growth Rates were, 1)compared between sites. and 2), were correlated with morphometric measurements. No significant results were produced. In correlating trait measurements between sites and between one another in order to determine whether migration may be producing trends, again no significant relatlonships were obtained. A comparison of jack pine with the similar species lodgepole pine suggests that if the same factors controlling the migration of lodgepole pine also control jack pine migration, wing loading should be less in more recent populations. However, this study indicates no significant results in this respect. It is suggested, however, that a further sampling south along the latitudinal transect may produce significant results.

abstract: Thesis

abstract: Candidate in Philosophy


title: Life Extension and the Domination of the Body

contributor:
Gedge, Elisabeth
Philosophy

subject:
Death
Prolongevitism
Bioethics
Life Extension

abstract: This paper investigates the prolongevitist debate; that is, the debate surrounding whether to extend human lifespans through medical technology (prolongevitism) or not (apologism). Apologists such as Daniel Callahan emphasize an approach to this debate which focuses on social self-criticism and ideology. I investigate the way the ideology of medicine Callahan describes enables modern medicine to dominate the body and discover that this ideology relies on a dualist conceptual structure. I describe the way in which mind/body dualism functions as an important component of this ideology of domination. By identifying this dualist structure as an essential component of the ideology of medicine, I make it possible to critique and find alternatives to potential solutions to this ideology of medicine. Through this strategy, I criticize standard apologist responses to the prolongevitist debate. While I share the apologist concern regarding the ideology of medicine, I believe their response to the problem of ideology is inadequate. I find alternative answers to the question of how to overcome the ideology of the body through theories of discourse and phenomenology. My new approach emphasizes cultivating a positive embodiment relationship through phenomenological practices and the criticism and creation of new discourses of the body.

abstract: Dissertation

abstract: Master of Arts (MA)


title: Stomatal Response of Carex Aquatilis to Climate Conditions in a Subarctic Coastal Wetland During the Growing Season

contributor:
Rouse, Wayne
Geography

subject: stomatal resistance, evapotranspiration, James Bay, subarctic wetland, Carex Aquatilis, plants

abstract: Plants can control water loss through their stomata in response to changing environmental conditions. Some research has been done on predicting stomatal resistance from climate variables such as solar radiation intensity, temperature, and vapour pressure deficit, but the factors involved are numerous and complex. Information on evapotranspiration from non-cultivated vegetation under field conditions is relatively scarce. This study was carried out in a subarctic coastal wetland on James Bay, an area for which little data exists. Leaf resistance measurements were collected in the field with a diffusion porometer as the 1988 growing season reached its peak. Meteorological data were also recorded. The main species examined was Carex aquatilis, a common sedge with a circumpolar distribution. As has been previously found, field resistances were lower than those reported for greenhouse-grown specimens. Attempts to derive a multivariate regression model to predict leaf resistances had a maximum explained variance under 40%. However, Principal Components Analysis suggested that cool, sunny, low-VPD conditions tend to accompany low leaf resistances. An increase in leaf resistance occurs when solar radiation intensities are low, or when the air is warm and dry. In addition, Carex aquatilis from drier areas showed less growth, and generally higher leaf resistances, than plants growing in saturated soils. Since climate models predict higher temperatures and lower soil moisture for the study area, due to carbon dioxide-induced warming, higher stomatal resistances could result. If these changes are severe enough, primary production could be reduced in the subarctic wetlands. Through the food chain, this could possibly affect species important to the economy and ecology of northern areas.

abstract: Thesis

abstract: Candidate in Philosophy


title: Glycerin Suppositories Used Prophylactically in Premature infants (SUPP): A pilot study for a multicentre randomized controlled trial

contributor:
Peter, Rosenbaum
Luis, Braga
J. Mark, Walton
Sarah, Jones
Health Research Methodology

subject:
glycerin
suppository
premature infant
enteral feeding
necrotizing enterocolitis

abstract:
BACKGROUND: Adequate feeding is a significant challenge for premature infants in the neonatal intensive care unit. These patients are often treated with glycerin suppositories to stimulate the passage of meconium and prevent feeding intolerance. Unfortunately, the evidence for this practice is limited and inconclusive.

METHODS: We conducted a systematic review on the use of glycerin suppositories and enemas in premature infants. Following this, we conducted a pilot study for a multicenter randomized controlled trial of premature infants randomized to glycerin suppositories or a placebo procedure once daily. Outcomes included rate of recruitment, rate of reaching the primary endpoint of full enteral feeds, treatment-related adverse events, and cost.

RESULTS: Twenty-two infants were recruited and randomized active treatment or the placebo procedure. Gestational age was 24-32 weeks and birth weight was 500-1500 grams. During the study period, 61 infants were screened, 46 (75%) were eligible and approached for consent, 25 (54%) consented to participate, 22 (48%) were randomized, and 19 reached the primary endpoint of full enteral feeds. Three infants (14%) experienced rectal bleeding 5 to 43 days after completing study treatments. An anal fissure was also noted in two of these patients (9%). There were no cases of rectal perforation or necrotizing enterocolitis. Protocol violations occurred during 14 of 130 (11%) treatment days. The total cost for running this pilot study was estimated to be $16,000. A revised sample size calculation for the multicenter study indicated that 72 infants would be required to detect a treatment effect of 2 days faster to full enteral feeds.

CONCLUSIONS: This external pilot study suggested that conducting a multicenter randomized controlled trial of glycerin suppositories in premature infants is feasible and safe. In the multicenter trial, we recommend tolerating a lower platelet count in the exclusion criteria, using a fixed rather than variable treatment duration, conducting follow-up assessments at predefined time points, and conducting an interim analysis to ensure that treatment is not associated with increased risk of necrotizing enterocolitis.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Feeding is a significant challenge for premature babies in the neonatal intensive care unit. These infants have immature digestive tracts and may not have normal bowel movements until a week or more after birth. One way to help premature babies is by giving them a medication called glycerin suppositories. This treatment is already used in many hospitals around the world. Unfortunately, previous studies have not shown for sure that this medication is actually helpful. In fact, there are some signs that using glycerin suppositories in premature infants may be harmful. We conducted a small study involving 22 premature infants randomized to either glycerin suppositories or a placebo. We found that it is safe and practical to do a larger study on this treatment involving multiple hospitals and hundreds of premature babies. The larger study will have enough participants to full show the risks and benefits of using glycerin suppositories to treat these infants.


title: Perturbed Angular Correlation Studies in Platinum

contributor:
Cameron, J. A.
Physics

subject: perturbed, angular, platinum, isotopes, alloy

abstract:
<p> Two isotopes of platinum, Pt192 and Pt194, have been investigated using Ge(Li) vs. NaI coincidence techniques. The following corrected angular distributions and mixing ratios
in Pt192 were obtained:  468-316 keV     A22 = 0.100(8)       A44 = 0.011(8)
                                    604-316 keV     A22 = -0.410(15)    A44 = -0.070(22)
                                    308-612 keV     A22 = -0.120(20)    A44 = -0.027(20)
                                    417-468 keV     A22 = -0.120(26)    A44 = -0.110(30)

                                                            δ308 = -9.4(15)
                                                            δ604 = + 3(1)
                                                            |δ417|> 11                                                         g factors for the following five levels of these nuclei were obtained using the method of perturbed angular correlations where the perturbing agent was the hyperfine field on platinum in an iron alloy:                                                                                Pt192     316 keV     g = 0.30(3)
                                            Pt192     612 keV     g = 0.28(7)
                                            Pt192     785 keV     g = 0.14(10)
                                            Pt194     329 keV     g = 0.28(3)
                                            Pt194     622 keV     g = 0.22(4)                                           A comparison with the predictions of a microscopic collective model, the pairing-plus-quadrupole model, is made.

abstract: Thesis

abstract: Master of Science (MSc)


title: Seismic Performance Assessment of Ductile Reinforced Concrete Block Structural Walls

contributor:
El-Dakhakhni, Wael
Drysdale, Robert
Civil Engineering

subject:
Concrete Blocks
Collapse
Displacement-based
Force-based
Fragility
Incremental Dynamic Analysis
Performance-based
Shear walls

abstract: This dissertation is relevant to structural engineers focusing on seismic design of structures using reinforced masonry. Specifically the thesis focuses on the seismic performance of reinforced masonry shear walls as seismic force resisting systems.

abstract: Reinforced masonry (RM) has been gaining a wide acceptance in the low- and mid-rise construction market as an economic and durable structural system. However, challenges still exist in the area of seismic design because of the poor performance of unreinforced masonry during recent earthquake events in Iran 2003, Haiti 2010, Japan 2011, New Zealand 2011 and Nepal 2015. The dissertation investigated the seismic performance of six concrete block structural walls in an effort to evaluate their force-, displacement- and performance- based seismic design parameters. The walls fall under the ductile shear wall/special reinforced wall seismic force resisting system (SFRS) classification according to the current North American masonry design standards. More specifically, the dissertation is focused on evaluating if such walls, designed under the same prescriptive design provisions, having different cross-section configurations would possess similar seismic performance parameters. This was established through an experimental and analytical program by subjecting the walls to a displacement controlled quasi-static cyclic analysis. Different wall configurations were tested including, rectangular, flanged and slab-coupled walls. Test results confirmed that walls designed under the same SFRS classification, but with different configurations, have different seismic performance parameters that included ductility capacity; yield and post yield displacement; stiffness degradation; period elongation and equivalent viscous damping. The current North American masonry design provisions do not account for such difference in the ductility capacities between the walls. The thesis analyses were concluded by quantifying the seismic vulnerability of a RM SFRS comprised of shear walls similar to those tested, through the development of collapse fragility curves and the assignment of an adjusted collapse margin ratio, ACMR following the FEMA P-58 and P-695 guidelines. The system were deemed acceptable since the ACMR was greater than ACMR10% (2.35 > 2.31). Therefore, the selected RM SFRS which was designed to meet the prescriptive requirements of the ductile masonry walls classification of the CSA S304 (CSA 2014), shows potential capacity against collapse under high intensity earthquakes in one of the highest seismic zones in western Canada and it should be considered as a viable SFRS to be used in seismic design. The procedure described in the chapter can be adopted to investigate the collapse fragility of other SFRS in different seismic regions through careful selection and scaling of the ground motion records associated with such region's seismicity.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Automated Nematode Tracking System

contributor:
Shirani, Shahram
Gupta, Bhagwati
Selvaganapathy, P. Ravi
Electrical and Computer Engineering

subject:
C. elegans
Caenorhabditis elegans
Tracking
Automation
Research Automation
Nematode
Microchannel
Microfluidic Electrotaxis
Computer Vision
Image Processing

abstract: Many diseases, such as Parkinson's disease and heavy metal poisoning, are associated with impaired or aberrant locomotion. Because the underlying mechanisms are difficult to study in humans, simpler metazoans like Caenorhabditis elegans are commonly employed to model these diseases. C. elegans is especially useful in this respect because its innate electrotactic behaviour allows instantaneous manipulation of its locomotion using mild electric fields in a microfluidic environment, the results of which can be captured on video. However, extraction of locomotory data from these videos is a major bottleneck to the throughput of the microfluidic electrotaxis platform. In the present study, we describe the development of novel software to analyze electrotaxis videos in an automated fashion. The software, dubbed the Automated Nematode Tracking System (ANTS), uses efficient, parameterless computer vision techniques to simultaneously track and assess movement characteristics of ambulating animals. In combination with the previously described microfluidic electrotaxis platform, ANTS promises to accelerate research with C. elegans models of locomotory dysfunction.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: A SUBSURFACE STUDY OF THE MIDDLELOWER SILURIAN THOROLD SANDSTONE FROM CONSUMERS' GAS SILVER CREEK 004 GRIMSBY POOL; NORTH-CENTRAL LAKE ERIE

contributor:
Middleton, G.V.
Geology

subject: subsurface, Middle-Lower, Gas, Grimsby, Pool, shoreface, Environment, quartz, sandstorm, detrital, authigenic

abstract: Examination of subsurface cores of the Middle-Lower Silurian Thorold Sandstone from Consumers' Gas Silver Creek 004 Grimsby Pool indicate the presence of a single laminated sandstone facies deposited in a lower shoreface environment. Subsurface thin sections show greater development of quartz cement in the form of quartz overgrowths when compared to thin sections from surface outcrop leading to a porosity decrease of 20%. Petrographic and cathodoluminescence studies reveal that concavo-convex and sutured grain contacts, responsible for 80% of the grain contacts within the Thorold Sandstone, are generally between authigenic overgrowths and not detrital grains indicating that pressure solution is not the major source of silica within the Thorold Sandstone. Studies of detrital and authigenic clays utilizing a combination of thin section, scanning electron microscope and X-ray diffraction techniques show that illite (both detrital and authigenic) is the dominant clay mineral within the Thorold Sandstone in the 004 Pool, followed by approximately one half as much detrital kaolinite and minor authigenic chlorite. Shallow maximum depth of burial ( 786 to 1160m) and low diagenetic temperatures (30°c) suggest that clay minerals are unlikely to have undergone extensive diagenetic transformation. Consequently, detrital minerals represent the clay minerals present at the time of deposition while authigenic clays form by direct precipitation from pore fluids. During eodiagenesis mechanical compaction has reduced sandstone porosity from 40% to 28 to 29% while during mesodiagenesis the progressive paragenetic assemblage of authigenic quartz overgrowths, authigenic chlorite and authigenic illite have reduced porosity to its present value of 4 to 10%.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Type-Safe Domain-Specific Code Graph Construction Using Scala

contributor:
Anand, Christopher
Computing and Software

subject:
scala
programming language
domain-specific
haskell
type safety
coconut

abstract:
As an extension to the ongoing Coconut (COde COnstructing User Tool) project at McMaster University, we present a Scala library for constructing type-safe domain-specific languages that uses Coconut’s hypergraph-based representation of code (code graphs) as the intermediate representation. Our library automatically produces strongly typed, deeply embedded DSLs given only a minimal specification of the DSL’s value types and primitives. We make extensive use of path-dependent types and implicit argument lookup to construct a type-safe interface on-the-fly, rather than requiring DSL designers to explicitly create a type-safe interface.

In this thesis we present our library and demonstrate its utility as both a general-purpose DSL framework and as a suitable platform for continued research on the Coconut project. By giving practical examples of the library in use, we demonstrate both its general utility, and the striking swiftness with which new DSLs may be constructed, especially compared to the previously laborious Haskell DSLs of Coconut.

abstract: Thesis

abstract: Master of Science (MSc)


title: Estimating Wind Profile Parameters Over a Maturing Crop

contributor:
Davies, J. A.
Geography

subject: wind, profile, parameters, maturing, crop

abstract:
Abstract Not Provided.
Thesis
Bachelor of Science (BSc)


title: The Mass Spectra of Some Monocyclic, Bicyclic, and Tricyclic Sulfur and Selenium Compounds

contributor:
MacLean, D. B.
Chemistry

subject: mass spectra, sulfur, selenium, compounds, ions, fragmentation

abstract: The mass spectra of disubstituted 1,4-dithiane, 1,4-oxathiane, and 1,4-oxaselenane, as well as the mass spectra of some disubstituted bicyclic and tricyclic sulfur and selenium compounds, were studied. The exact composition of the major ions of many of these compounds was determined. Fragmentation mechanisms are proposed to account for the major peaks in their spectra.

abstract: Thesis

abstract: Master of Science (MSc)


title: Lewis Acid Catalyzed Cycloadditions

contributor:
Childs, R. F.
Chemistry

subject: lewis, acid, catalyzed, cycloadditions, stoichiometry

abstract:
 This thesis describes an attempt to develop a potentially useful route to
seven-membered carbocycles. α-Diketones and their enol ether derivatives were proposed to be suitable three-carbon cycloaddition dienophiles when complexed with a Lewis acid. Reaction with 1,3-dienes should then lead to the desired cycloheptyl system.

 1H-NMR and 13C-NMR studies were used to determine the stoichiometry and charge delocalization of complexes formed between 2,3-butanedione, 1,2-cyclohexanedione,
2-methoxy-cyclohex-2-en-1-one and the Lewis acids TiCl4 and SnCl4. Observations
from these studies suggested that 1,2-cyclohexanedione and 2-methoxy-cyclohex-2-en-1one
could behave as substituted allyl cations when complexed with TiCl4 or SnCl4.

 Reaction of the 1,2-cyclohexanedione/TiCl4 and 2-methoxy-cyclohex-2-en-1one/
TiCl4 complexes with 1 ,3-butadiene gave rise to six-membered carbocycles from
[4C+2C] cycloadditions. The reaction of 2,3-butanedione-mono-trimethylsilyl enol
ether/TiCl4 complex with 1,3-butadiene gave a mixture of the [4C+2C] and [4C+3C]
cycloaddition products.

abstract: Thesis

abstract: Master of Science (MSc)


title: Thermo-Catalytic Polymerisation in Wood

contributor:
Hodgins, J. W.
Chemistry

subject: thermo-catalytic, polymerisation, monomers, wood

abstract: An experimental investigation of polymerisation of several monomers in wood was performed using free radical initiators such as benzoyl peroxide and 2-azo-bis-isobutyronitrile. The most promising comonomer system appeared to be styrene and acrylonitrile. As a result of copolymerisation of styrene and acrylonitrile in the cell cavities of wood, many improvements in physical properties of wood resulted. The improvement in physical properties of wood containing thermo-catalytically copolymerised styrene and acrylonitrile was found to be better than those of radiation initiated graft copolymerised wood. Thermo-catalytically produced wood polymer combinations showed as much improvement in physical properties as shown by those produced by radiation initiation without the use of swelling agents.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Photo-Addition of 2-Cyclohexenone and Norbornadiene

contributor:
McCullough, J. J.
Chemistry

subject: photo-addition, norbornadiene, ketones, formation

abstract: The photo-addition of 2-cyclohexenone to norbornadiene has been investigated. A substantial proportion of the products formed were α, β unsaturated ketones. The structure of these has been assigned and a rationale is presented to explain the formation of these products.

abstract: Thesis

abstract: Master of Science (MSc)


title: Phase Shift Approximation to Reaction Matrix Elements in an Oscillator Representation

contributor:
Sprung, Donald W. L.
Physics

subject: phase shift, matrix, elements, oscillator, forces, nuclear

abstract: This thesis presents a derivation of a method to obtain two-body, diagonal and non-diagonal, reaction matrix elements for central and tensor forces respectively directly from nucleon-nucleon scattering phase shifts. This procedure eliminates the necessity for constructing a nuclear potential.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Calculation of Phonon Dispersion Curves in Metals With Application to Aluminum

contributor:
Vosko, S. H.
Physics

subject: phonon, dispersion, metals, application, aluminum, plane waves, matrix, element

abstract: Pages 6 and 7 are labelled as the same page.

abstract:
 The purpose of this work is to calculate phonon dispersion curves in metals paying particular attention to the evaluation of a new electron-ion matrix element by use
of orthogonalized plane waves (OPW). The dynamic role of the electrons in screening the electron-ion interaction has been studied. Our formalism makes use of recent developments
in the theory of the many-body problem. Applications of our theory have been made to aluminum. The pseudopotential part of the OPW electron-ion matrix element produced an
overscreening of the frequency modes. Comparison is made to the use of the Bardeen matrix element. Our results strongly suggest that this calculation applied to lead would
explain the magnitude of Kohn kinks observed by Brockhouse et al. (B 62a).

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Nuclear g-Factors in Iron 55 from Perturbed Angular Correlation Studies

subject: nuclear, perturbed, angular, correlation, chromium

abstract:
 The (α,n) reaction on natural chromium has been used to study levels in 55Fe up to 2.5 MeV excitation. Intensities and angular distributions of the decay gamma rays were measured, yielding branching and E2/M1 mixing ratios. In a magnetized target of the alloy Cr20Fe80, the
rotation of the angular distributions was observed. Using recently determined lifetimes and the average internal field of 277 kOe measured in the target material by Mössbauer absorption, the following g-factors are obtained: - 931 keV, 5/2- -: +1.2 ±0.5 1316 keV, 7/2- -: +0.5 ± 0.5 1408 keV, 7/2- -: -0.77 ± 0.16

abstract: Thesis

abstract: Master of Science (MSc)


title: Radio Resource Management in Wireless Networks with Multicast Transmissions

contributor:
Zhao, Dongmei
Zheng, Rong
Electrical and Computer Engineering

subject:
Radio resource management
opportunistic scheduling
Netwrok coding
Power allocation
multicast D2D communications
optimization

abstract:
With the increasing demand for wireless communications, radio resource management (RRM) plays an important role in future wireless networks in order to provide higher data rates and better quality of services, given the limited amount of available radio resources. Although some specific features of wireless communication networks cause challenges to effective and efficient RRM, they bring opportunities that help improv- ing network performance and resource utilization. In this thesis, we focus on RRM issues related to the broadcast/multicast nature in wireless communication networks. The work is divided into two parts.
In the first part, we exploit how to take advantage of the broadcast nature of wire- less transmissions in RRM by opportunistically applying two-way relaying (or network coding) and traditional one-way relaying. Different objectives are considered, includ- ing maximizing total packet transmission throughput (Chapter 2), minimizing costs related to transmission power and delay (Chapter 3), and minimizing packet transmis- sion delay subject to maximum and average transmission power limits (Chapter 4). While designing these scheduling schemes, the random traffic and channel conditions are also taken into consideration. Our results show that the proposed opportunis- tic scheduling schemes can indeed take good advantage of the broadcast feature at the relay nodes and achieve much higher throughput and, in some scenarios, provide close-to-optimum QoS performance.
The second part (Chapter 5) of the thesis deals with the issue of efficient resource
management in multicast communications, where we study channel sharing and power allocations for multicast device-to-divice (D2D) communication groups underlaying a cellular network. In such a scenario, D2D multicasting together with the mutual inter- ference between cellular and D2D communications, makes the interference conditions and power allocations a very complicated issue. Different approaches are proposed that allow each D2D group to share the cellular channels and allocate transmission power to each D2D and cellular transmitter, so that the sum throughput of D2D and cellular users is maximized. Our results indicate that it is possible to achieve close-to-optimum throughput performance in such a network.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


contributor:
Shannon, Harry
Health Research Methodology

subject:
Retirement
Labour Market
Older Workers
Canada
Aging
Health Status
Employment
Longitudinal Data
Scoping Review

abstract:
TITLE: Work, Health and the Economy: Examining Predictors of Early Retirement Among Older Canadian Workers

OBJECTIVES: To investigate the contribution of socio-demographic, health, work, and health behaviour factors to the transition from work to early non-disability retirement among older Canadian workers during a period of economic recession compared to a period of non-recession.

METHODS: A systematic scoping review was conducted to identify the predictors of early retirement reported in the published literature. This study also used data from Statistics Canada’s National Population Health Survey to explore the predictors of early retirement among two prospective cohorts of older Canadian workers aged 45-64 that spanned a non-recessionary economic period in Canada (cohort 1: 1994-1999) and a period which included an economic recession (cohort 2: 2006-2010). The impact of various factors on early retirement was examined using logistic regression analyses.

RESULTS: Findings from the systematic scoping review were used to construct a list of variables to explore as predictors in the model. Factors which were associated with higher transitions into early retirement included older age (cohort 1: OR=1.42; cohort 2: OR=1.31), living in Quebec (cohort 1: OR=2.26), occasional (cohort 1: OR=2.56) or regular drinking (cohort 1: OR=2.32), low job satisfaction (cohort 1: OR=3.42; cohort 2: OR=3.33), working part-time (cohort 1: OR=2.16; cohort 2: OR=2.26), and employment in public administration (cohort 1: OR=2.77). While being a woman (cohort 1: OR=0.59), immigrant (cohort 1: OR=0.57), and higher job security (cohort 1: OR=0.73) were associated with lower exits to early retirement. There were differences observed in the effects of occasional and regular drinking, and for living in Quebec, on early retirement between the two contrasting economic time periods. The comparison of the provincial effect suggested that early retirement varies to some extent with the provincial unemployment rate.

CONCLUSIONS: Predictors of early retirement among older Canadian workers are multifactorial. Results suggest that factors beyond individual determinants may influence early retirement and future research is needed to better understand what aspects of the provincial context are driving retirement decisions.

abstract: Thesis

abstract: Master of Science (MSc)


title: REVEALING THE GROUND STATE PROPERTIES OF THE S=1/2 KAGOMÉ HEISENBERG ANTIFERROMAGNET: 17-O SINGLE-CRYSTAL NMR INVESTIGATIONS OF ZNCU3(OH)6CL2

contributor:
Imai, Takashi
Physics and Astronomy

subject:
experimental condensed matter physics
highly frustrated magnetism
quantum spin liquid
NMR

abstract:
The experimental quest for a quantum spin-liquid state (QSL) in frustrated magnetic systems addresses fundamental scientific interests, as this intriguing quantum phase provides excellent grounds for discovering exotic collective phenomena. ZnCu3(OH)6Cl2 (herbertsmithite), an S=1/2 kagomé-lattice Heisenberg antiferromagnet, is the most promising candidate for experimentally realizing a QSL. However, despite years of intense research, the nature of its paramagnetic ground state remains highly debated. The root cause of the controversy lies in the difficulty in distinguishing the effects of defects from the intrinsic properties of the kagomé lattice.
In this thesis, we present 17-O nuclear magnetic resonance (NMR) measurements of an isotope-enriched ZnCu3(OH)6Cl2 single crystal. We succeeded in distinguishing the intrinsic magnetic behavior of the kagomé lattice from the defect-induced phenomena down to T~0.01J, where J~200K is the Cu-Cu super-exchange interaction. We identify NMR signals arising from the nearest-neighbor 17-O sites of Cu2+ defects occupying the Zn2+ interlayer sites. From the 17-O Knight shift measurements, we show that these Cu2+ defects induce a large Curie-Weiss contribution to the bulk-averaged susceptibility at low temperatures. Moreover, our 17-O single-crystal lineshapes show no signature of nonmagnetic Zn2+ defects within the kagomé lattice, and therefore, we rule out “anti-site disorder” as a cause of the paramagnetic ground state in ZnCu3(OH)6Cl2. Most importantly, we demonstrate that the intrinsic spin susceptibility of the kagome lattice asymptotically tends to zero below T~0.03J, indicating the presence of a finite gap Δ = 0.03~ 0.07J in the spin excitation spectrum; this gap is completely suppressed under the application of a high magnetic field of ~ 9T. The behavior of low-energy spin fluctuations probed by the 17-O nuclear spin-lattice relaxation rate is consistent with the gap signature observed for the 17-O Knight shift. In short, our 17-O NMR results provide the first experimental evidence for a gapped QSL realized in ZnCu3(OH)6Cl2.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: CONTRALATERAL BREAST CANCER IN WOMEN WITH EARLY STAGE BREAST CANCER

contributor:
Levine, Mark
Health Research Methodology

subject:
Breast Cancer
Contralateral

abstract:
Background:
There is uncertainty about the lifetime risk of contralateral breast cancer (CBC) in a woman who is diagnosed with early stage breast cancer. Studies report a wide range of rates of CBC between 2% and 35%.

Objectives:
(i) To determine the risk of CBC in women with early stage breast cancer, and (ii) to evaluate the risk of CBC in women who undergo adjuvant systemic treatment and adjuvant radiation treatment.

Methods:
PubMed, Ovid MEDLINE, EMBASE, Healthstar, Cochrane Central Register for Controlled Trials were searched. Studies were included if participants had: unilateral invasive breast carcinoma; 5 years of median follow-up; a minimum of 100 participants. Randomized controlled trials were included for the meta-analysis. A random-effects meta-analysis was used to estimate the pooled rate of CBC.

Results:
4571 articles were extracted out of which 22 randomized controlled trials were included in the final meta-analysis. The overall pooled rate of CBC was 0.36% per year, (95% CI, 0.32% - 0.41%). The rate of CBC in studies without adjuvant systemic treatment was higher than the rate without such treatment, 0.56% per year (95% CI, 0.40% to 0.77%) versus 0.35% per year (95% CI, 0.31% to 0.40%). The rate of CBC in studies with adjuvant radiation treatment was 0.26% per year (95% CI, 0.18% to 0.39%) which is similar to the rate in studies with radiation.

Conclusions:
The rate of CBC in women with early stage breast cancer is relatively low. This is important for breast cancer patients who are considering contralateral prophylactic mastectomy.

abstract: Thesis

abstract: Master of Science (MS)

abstract: The rate of contralateral breast cancer in women with early stage breast cancer is uncertain. In order to determine this rate, a systematic review and meta analysis was conducted. The rate of contralateral breast cancer in women with early stage breast cancer was found to be 0.36% per year. This rate appears to be constant for up to 10 years after the original breast cancer diagnosis. This data is important for women with breast cancer and their healthcare teams in order to make decisions about bilateral mastectomy.


title: USE OF MCMASTER PLUS FOR UPDATING SYSTEMATIC REVIEWS

contributor:
Iorio, Alfonso
Health Research Methodology

abstract:
Background
Systematic reviews (SRs) of treatment effect are evidence syntheses that inform clinical practice decisions and healthcare policy. To maintain validity, SRs should be regularly updated to include novel research. In reality, updating practices are irregular, with resource and time constraints often cited as major barriers. The McMaster Premium LiteratUre Service (PLUS) is a database of high quality, pre-appraised evidence, which may be of potential help in efficient updating of SRs.
Objective
To determine the utility of McMaster PLUS to increase the efficiency of systematic review updating
Methods
Updated Cochrane reviews published from January 2012-January 2013 with changed conclusions were identified. Using the PubMed IDs of references in the updated review, which were not present in the previous version, we looked for the presence of these references in the PLUS database. Further, using Clinical Query (CQ) filters on PubMed, we identified the references not found in PLUS.
Results
Eight hundred fifty-four unique trials, reported in over 1498 references were used to drive a change in conclusion in the 92 included reviews. Of the 854 unique trials, 180 (21.1%) were found in the PLUS database. All of the newly added trials were in PLUS for 8 of 92 reviews, and none of the newly added trials were in PLUS for 26 of 92 reviews. Of the 834 references not found in PLUS, there were 728 unique PubMed IDs. Using the sensitive CQ filter, 701 (96.2%) of these trials were identified.
Conclusion
PLUS included 21.1% of trials used to drive a change in conclusion in 92 Cochrane reviews. Furthermore, the CQ filters performed admirably in the retrieval of articles not found in PLUS. These alternate search methods should be considered when updating SRs to help increase the efficiency of the update process.  These methods should be further tested prospectively.

abstract: Thesis

abstract: Master of Science (MSc)


title: NGL RECOVERY PLANT FEED GAS COOLING BY EJECTOR REFRIGERATION – DESIGNED FOR HOT CLIMATE

contributor:
Mahalec, Vladimir
Chemical Engineering

subject:
Energy and Heat integration
Refrigeration
Renewable Energy
NGL Recovery Plant
Process Design
Ejector Refrigeration Cycle
Absorption Refrigeration Cycle
Solar Energy
CO2 Emission
Greenhouse Emission

abstract: This work suggests a new multiple ejector refrigeration cycle operated by an NGL Recovery Plant's waste heat as a replacement to the mechanical compression refrigeration cycle. This will result in significant power reduction and CO2 emission reduction.

abstract: Typical NGL plant compresses its feed to a high pressure (3040 kPa). The feed gas compressors’ discharge reaches approximately 150 OC.  After that, the feed is cooled by three-stage propane vapour compression refrigeration cycle.  This paper examines various options for thermal power cooling in such plants in order to eliminate part of the propane chilling system.  Since most of the new plants are located in desert climates, typical designs based on absorption refrigeration are not very efficient.   Design proposed in this work employs ejector refrigeration and it is based on 45 OC air as a cooling media (summer conditions in hot climates).  Performance factor has been defined as the total cooling provided by the refrigeration system over the total cooling required in the 1st cooling stage of the NGL Recovery Plant. Cooling based on a single N-pentane ejector cycle with N-pentane has COP of 0.342 and performance factor (ƞ) of 0.842. Multistage ejector N-pentane refrigeration system has COP of 0.714 and performance factor (ƞ) of 1.053.  For a typical 750 Million scf/d NGL plant, the new design saves $12 Millions in capital costs and $1.5 in annual electricity cost.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: ROLE OF THE ADENOSINE MONOPHOSPHATE-ACTIVATED PROTEIN KINASE IN MAINTAINING MUSCLE INTEGRITY AND INSULIN SENSITIVITY THROUGHOUT THE LIFESPAN

contributor:
Steinberg, Gregory
Medical Sciences

abstract: Introduction: Aging is associated with a progressive decline in skeletal muscle health. In both rodents and humans, aging-associated reductions in skeletal muscle AMP-activated protein kinase (AMPK) activity and mitochondrial function have been linked to the development of muscle insulin resistance, but whether these are precipitating factors causing insulin resistance is unknown. Autophagy is a cellular quality control process that is essential for tissue health and regulated by AMPK. Aging is also associated with reduced basal autophagy, but it has yet to be investigated if AMPK is required for autophagy in skeletal muscle. Methods: Insulin sensitivity was measured using glucose and insulin tolerance tests, the hyperinsulinemic-euglycaemic clamp and 2-DG uptake experiments. Autophagy was measured in the basal and fasted state by electroporating RFP-LC3 into skeletal muscle, inhibiting autophagic flux with colchicine, western blotting and qRT-PCR experiments. Results: We found that fasting mice lacking skeletal muscle AMPK (AMPK-MKO) results in hypoglycemia and hyperketosis. This is not due to defective fatty acid oxidation, but instead is related to a block in muscle proteolysis that leads to reduced circulating levels of alanine, an essential amino acid required for gluconeogenesis. Markers of muscle autophagy including phosphorylation of Ulk1 Ser555, Ser757 and aggregation of RFP-LC3 puncta are impaired. Consistent with impaired autophagy, aged AMPK-MKO mice possess a significant myopathy characterized by reduced muscle function, mitochondrial disease and accumulation of the autophagy/mitophagy proteins p62 and Parkin. Suprisingly, despite the considerable myopathy and mitochondrial disease observed in aged AMPK-MKO mice, skeletal muscle insulin sensitivity was preserved. Conclusions and significance: These data demonstrate that reductions in AMPK and mitochondrial activity do not cause age-induced insulin resistance, but do establish an essential requirement for skeletal muscle AMPK-mediated autophagy in preserving blood glucose levels during prolonged fasting as well as maintaining muscle integrity and mitochondrial function during aging.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Vibrational and Electronic Spectra of Cyanoacetylene

subject: vibrational, electronic, cyanoacetylene, energy, spectra, molecule

abstract:
 The infrared and Raman spectra of cyanoacetylene and deuterocyanoacetylene have been measured and ground state vibrational energy levels have been obtained from the analysis of these spectra.

 Two band systems have been identified in the absorption
spectrum of cyanoacetylene in the region 2700 - 2000 Å. Vibrational and rotational analyses have shown that the lower energy transition involves a non-linear planar upper state having A" symmetry. Approximate geometry of the molecule in the A" state has been determined.

 In the second electronic transition the upper state has been found to be linear. A vibrational analysis has been obtained on the basis of an electronically forbidden 1Δ<--- 1 Σ+ or 1 Σ- <--- 1 Σ+ transition, which is made allowed by vibronic interactions.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)