title: Examining the Needs of Families of School-Aged Children with an Autism Spectrum Disorder

contributor:
Ouellette-Kuntz, Hélène
Hunter, Duncan
Kelley, Elizabeth
Community Health and Epidemiology

subject:
Epidemiology
Health Services Research
Autism
Family Needs

abstract: Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2010-07-26 11:11:27.456

abstract:
Background. Children with autism spectrum disorders have complex needs requiring a broad range of supports. High demand for autism services has led to gaps in the provision of care, and there is little research examining whether families of school-aged children receive services reflective of their needs.
Objectives. The objectives of this thesis were to describe unmet needs reported by parents of school-aged children with an autism spectrum disorder and to examine the association between the child’s level of functional independence and the parent’s reported level of unmet need.
Methods. A review of the literature on needs assessments in autism was performed. A cross-sectional study was then conducted among parents of 101 children who (1) had an autism spectrum disorder, (2) were between the ages of 6 and 13 years, and (3) were living in Manitoba, South Eastern Ontario, Prince Edward Island, or Newfoundland and Labrador. Data were collected using a written questionnaire (Family Needs Questionnaire, Impact on Family Scale, demographic questions) and a telephone interview (Scales of Independent Behaviour-Revised, service use questions). Log binomial regression was used to examine the association between the child’s functional independence and the parent’s perceived unmet needs.
Results. The most commonly reported unmet needs were related to social inclusion for the child, information about special programs and services, and continuity of support. Families of children with high functional independence had lower unmet need compared to families of children with moderate functional independence (RR = 0.81, 95% CI = 0.67-0.99). Families of children with high functional independence, and who perceived a high level of impact of the child’s disability on the family, had greater unmet need (RR = 1.22, 95% CI = 1.03-1.45).
Conclusion. This thesis identifies family needs which have not been met by the service system. Assessments of child and family functioning may provide insight into unmet need that is not revealed simply by knowing a child’s diagnosis on the autism spectrum. Information about the unmet needs of families of children with autism spectrum disorders may help policy makers and service planners to develop resources and services that are responsive to their client group.

abstract: M.Sc.


title: Towards Quantum-limited Measurement with the Radio Frequency Superconducting Single-Electron Transistor

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

subject:
Physics
Single-electron transistor
Low temperature
Quantum limit
Nanolithography

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2010-08-10 17:38:43.798

abstract: In the past decade, nanomechanical resonators have found use in the work towards understanding mesoscopic quantum systems and the necessary validation of quantum mechanics on this scale. In 2010, the observation and state manipulation of a nanomechanical quantum system was achieved for the first time by O'Connell et al.. In 2002, Knobel and Cleland proposed to use a radio frequency superconducting single-electron transistor (RF-SSET), a fast and sensitive charge amplifier, to sense the quantum-limited motion of a piezoelectrically coupled nanomechanical resonator. The work presented in this thesis is towards the realization of the RF-SSET component of this device. An in-house fabrication recipe for making SETs with tunnel junction areas < 100^2 nm^2 and resistances between 20 kΩ and 150 kΩ was developed, in the end producing six SETs with resistances (36 ± 8) kΩ that were not susceptible to aging effects. Three measurement circuits were designed and used to characterize one of these SETs in the superconducting state (SSET) and operated in the DC and RF modes in a cryostat at a base temperature of 320~mK. Lock-in measurements revealed the SSET junction capacitances as 206 and 305 aF, contributing to a charging energy of (296 ± 11) x 10^(-6) eV. The resonant LC tank, which permitted RF operation, was also characterized at base temperature. The charge sensitivity of the RF-SSET was 6.8 x 10^(-5) e/√Hz (with uncertainty between 9.6 x 10^(-4) e/√Hz and 3.5 x 10^(-5) e/√Hz). With moderate improvements to the impedance matching network formed with the LC tank and greater junction resistances, an RF-SSET charge sensitivity on the order of 10^(-6) e/√Hz, required for sensing the quantum-limited motion of the nanomechanical resonator, should be achieved.

abstract: M.Sc.


title: Essays on Inflation and Output: A Search-Theoretic Approach

contributor:
Head, Allen
Koeppl, Thorsten V.
Economics

subject:
Economics
Monetary Policy
Search Theory
inflation and output

abstract: Thesis (Ph.D, Economics) -- Queen's University, 2010-07-17 00:52:41.487

abstract:
This dissertation examines the welfare effects of inflation on employment and output in three different market settings. The theoretical frameworks build on recent studies in the monetary search literature that explicitly models the microfoundations of money and study how monetary policy interacts with real variables.

The first essay studies the relationship between inflation and unemployment in a general equilibrium framework where inflation has differential effects on employed and unemployed workers. The model finds that inflation can either increase or decrease employment and output, depending on goods and labor market institutions. Sales taxes, the degree of competitiveness in the goods market and imperfect indexation of unemployment insurance benefits are the major factors determining the direction of this relationship. Through a comparison of these parameters, the model predicts an inflation-unemployment relation that is qualitatively consistent with the empirical evidences.

The second essay, co-authored with Liang Wang and Randall Wright, investigates the effect of inflation on people's trading behavior in the goods market. By focusing on buyers' search intensity on the extensive margin, the model unambiguously predicts a rise in inflation leads to an increase in the speed with which agents spend their money and velocity. This is consistent with the phenomenon described by the conventional "hot potato" effect of inflation. We also discuss the welfare implications of different monetary policy. In some circumstances inflating above the Friedman rule may be optimal, but the effect of inflation on output is always negative.

The third essay, co-authored with Allen Head, Guido Menzio and Randall Wright, examines the effect of monetary growth on output in a general equilibrium model where price stickiness arises as an equilibrium outcome. The model makes several predictions about individual firms' price adjustment behavior that are consistent with micro data. For instance, the frequency (duration) of price changes increases (decreases) with inflation and the price change hazard declines over time. In contrast to the New Keynesian literature, price rigidities in our model does not generate monetary non-neutrality. Higher inflation reduces real output in the long run, but changes in the aggregate price level has no effect on real allocations.

abstract: PhD


title: The Modification, Design and Development of a Scaled-down Industrial Furnace with Interchanging Burners for Academic Use

contributor:
Grandmaison, Edward W.
Chemical Engineering

subject:
Combustion
Industrial Furnace
Energy
Emissions
Control and Safe Operating Strategies
Burners
Hottel's Zone Method
Radiative Heat Transfer

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2010-07-19 09:50:22.797

abstract:
Industry is heavily dependent on the process of combustion and with a projected rapid increase for the demand of combustion-derived energy it is imperative to expose a new age of engineering professionals to the discipline of combustion engineering.
One purpose of this study was to modify an existing scaled-down industrial furnace and to retrofit it with the ability to interchange burners for academic application and combustion testing.  A number of available industrial burners are presented and their qualities and drawbacks discussed. The modification of an existing scaled-down industrial tunnel furnace is proposed in this work with the objective of providing users with exposure to the control and safe operating strategies associated with industrial combustion.
The furnace system simulates a square-shaped tunnel geometry commonly found in industrial applications.  A single nozzle mix burner is mounted along the furnace axis and operated with supporting equipment such as a burner control safeguard, a gas train, and an air supply.  Details of the furnace are provided in this work.  The concept of radiative heat transfer within a combustion enclosure is demonstrated through furnace simulation with Hottel’s Zone Method.

abstract: M.A.Sc.


title: The Epidemiology of Chronic Pain in Canada Between 1994 and 2008: Results From the National Population Health Survey and the Canadian Community Health Survey

contributor:
Van Den Kerkhof, Elizabeth
Nursing

subject:
Chronic Pain
Sociodemographic Factors
Predictors
General Population
Incidence
Prevalence

abstract: Thesis (Master, Nursing) -- Queen's University, 2010-07-20 13:38:13.996

abstract:
Background: Chronic pain is prevalent worldwide and is estimated to range from 2% to 55% in the general population.  There is a limited understanding of the prevalence and incidence of chronic pain in Canada.  Furthermore, our understanding of the sociodemographic predictors of chronic pain is limited; thus we are poorly positioned to identify potential populations at risk.
Objectives: The primary objectives for this study included: 1) to determine the prevalence and incidence of chronic pain and pain-related interference in Canada over time and, 2) to determine the influence of sociodemographic predictors on the development of chronic pain by sex in the Canadian adult population over 12 years.
Methods: Using data from the cross-sectional components of the National Population Health Survey (NPHS) (1994/95, 1996/97, 1998/99) and the Canadian Community Health Survey (2000/01, 2003, 2005, 2007/08), we examined the prevalence and interference of chronic pain.  The longitudinal component of the NPHS was used to determine the incidence and sociodemographic predictors of chronic pain.  Chronic pain was defined as the presence of “usual pain”.
Results: The prevalence in the cross-sectional samples ranged from 15.1% to 18.9%.  In the longitudinal sample, the incidence ranged from 5.4% to 7.8% and the prevalence ranged from 15.3% to 19.5%.  Women, compared to men, had a higher prevalence, but not incidence of chronic pain each year.  Of those individuals reporting chronic pain, the majority reported at least a few activities prevented.  Women who were older, with lower education, and widowed, separated, or divorced were more likely to develop chronic pain.  There were no sociodemographic risk factors for chronic pain in men.
Conclusion/Implications: This population-based study supports previous research findings indicating that chronic pain affects daily activities of many Canadians.  Furthermore, this is the first population-based prospective study examining the incidence and sociodemographic predictors of chronic pain in Canadians.  Further study with more detailed definitions of pain and pain-related interference is warranted.  Moreover, our findings suggest that older women are more likely to develop chronic pain and that men and women may have different risk factors for chronic pain, suggesting the need for gender-based preventative interventions.

abstract: I am planning to publish my three manuscripts.

abstract: MNSc.


title: Local invariants for biological motion perception

contributor:
Troje, Nikolaus F.
Neuroscience Studies

subject:
biological motion
inversion effect

abstract: Thesis (Ph.D, Neuroscience Studies) -- Queen's University, 2010-07-21 08:34:58.564

abstract: Observers can retrieve the facing direction of a walker from point-light displays that are devoid of structure-from-motion information and retain solely local motion signals.  This ability is orientation-dependent and relies on the motions representing the feet of the agent.  The experiments described here were designed to investigate visual sensitivity to local cues contained in biological motion.  Initial experiments revealed that local biological motion carries information about animacy in addition to the agent’s facing direction in an orientation-dependent manner (Chapter 2).  The mechanism underlying the perception of local biological motion can be dissociated from that underlying the retrieval of global structure-from-motion information according to characteristics such as sensitivity to learning and noise (Chapter 3).  Further experiments revealed that the orientation-dependency for perceiving local biological motion is carried by vertical acceleration in the foot’s motion (Chapter 4).  The importance of acceleration for biological motion perception raises the need to achieve a better understanding of acceleration sensitivity across various parameters such as stimulus size.  To this end, Chapter 5 showed that acceleration thresholds for perceiving a linearly accelerating stimulus scale according to mean velocity as predicted by size invariance and are inversely proportional to stimulus duration.  An important role for acceleration for the perception of biological motion was further corroborated by findings in an evolutionarily guided psychophysical search for the adequate local motion, defined as one that carries maximal directional information and a large inversion effect (Chapter 6).  Finally, although orientation-dependency is a pervasively demonstrated characteristic of biological motion perception, the reference systems in which the stimuli are encoded are unclear.  The experiments in Chapter 7 revealed that both global structure and local motion aspects of biological motion, like faces, are primarily coded in an egocentric frame of reference.  Unlike faces however, there is an additional contribution of non-visual information about gravity for the perception of biological motion.  These findings are finally discussed in the context of emerging behavioural, neuroimaging, and electrophysiological work that further characterize a local motion mechanism that is proposed to serve as a fundamental first stage towards interpreting animate motion patterns.

abstract: PhD


title: The Desire to Fill: Addiction and British Visual Culture, 1751-1919

contributor:
Helland, Janice
Art History

subject: Art Addiction

abstract: Thesis (Ph.D, Art History) -- Queen's University, 2010-07-21 13:31:48.788

abstract:
In “The Desire to Fill” I examine visual culture, including paintings, graphic art, advertisements and architecture, in relation to the lived experience of addiction.  My study begins in 1751, the year that William Hogarth produced his engravings Gin Lane and Beer Street, and it ends in 1919, the year that Alfred Priest exhibited his painting Cocaine at the Royal Academy’s annual Summer Exhibition.  There are four underlying arguments in this text.  First, that addiction to drugs and alcohol is a manifestation of a desire to “fill a void.”  Second, that addiction has long been thought to be legible from the body.  Third, that addiction cannot be reliably read from the body, whether in life or an image.  Fourth, any project that is concerned with addiction and visual culture is therefore a paradoxical one, and must, by necessity, be a speculative one.
	My methodological approach in this text is influenced by feminist theory and queer theory, and I explore the history of addiction using a continuist framework.  In other words, I suggest that, although the identities of the “addict” and “alcoholic” as we know them today were discursively constructed at the end of the nineteenth century, people experienced addiction before these identities came into being.  In that vein, I suggest that the woman in Hogarth’s Gin Lane is an alcoholic, and I show how anxieties about alcoholic mothers have remained remarkably consistent over the last three hundred years.  I also discuss graphic artist George Cruikshank’s experiences as a temperance advocate after he stopped drinking, gin palaces and women’s desire for alcohol, the social and legal ramifications of addiction, and, finally, cocaine and tobacco addiction after the First World War.  Ultimately, I examine the visual culture of addiction in order to destabilize stereotypes and myths about alcoholics and drug addicts that are still circulating today.

abstract: PhD


title: Communications Over Multiple Best Singular Modes of Reciprocal MIMO Channels

contributor:
Gazor, Saeed
Electrical and Computer Engineering

subject:
SVD
Channel Identification
Closed Loop Communication
Adaptive Algorithms
Singular Modes
Signal Processing
Filter Mismatch
Channel Training

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2010-07-21 16:53:33.077

abstract:
We consider two transceivers equipped with multiple antennas that intend to communicate i.e. both of which transmit and receive data in a TDD fashion. Assuming that the responses of the
physical communication channels between these two nodes are linear and reciprocal (time invariant or with very slow time variations), and by exploiting the closed loop conversation between these nodes, we have proposed efficient algorithms allowing to adaptively identify the Best Singular Mode (BSM) of the channel (those algorithms are for training, blind, and semi-blind channel identification). Unlike other proposed algorithms, our proposed adaptive algorithms are robust to noise as the involved step-size allows a trade-off to reduce the impact of the additive noise at the expense of some estimation delay. In practice, however, the reciprocity of the equivalent channels is lost because of the mismatch between the transmit and the receive filters of the communicating nodes. This mismatch causes significant degradation in
the performance of the BSM estimation. Therefore, we have also proposed adaptive self-calibrating algorithms (which do not require any additional RF circuitry) that account for such a mismatch. In addition, we have conducted a convergence analysis of the BSM algorithm and extended it to estimate multiple modes simultaneously. Finally, we have also proposed an adaptive, iterative algorithm that is capable of allocating power in such a way that maximizes the capacity of a SISO OFDM communication system.

abstract: PhD


title: Studies on the Chloramphenicol Halogenase CmlS

contributor:
Zechel, L. David
Chemistry

subject: Halogenase Chloramphenicol

abstract: Thesis (Master, Chemistry) -- Queen's University, 2010-07-22 16:39:52.059

abstract: The flavin-dependent halogenases are the most prevalent class of halogenase responsible for the regio- and stereoselective incorporation of halogens into natural products.  These enzymes require FAD, O2, NADH, and a flavin reductase to perform catalysis.  The majority of these enzymes are observed to catalyze the halogenation of aromatic substrates.  CmlS is a unique member of the flavin-dependent halogenase family in that it dichlorinates an alkyl group prior to incorporation onto the antibiotic chloramphenicol.  CmlS from the chloramphenicol producing strain Streptomyces venezuelae was cloned and heterologously expressed in Escherichia coli in high yield. The X-ray crystal structure of CmlS was solved to 2.2 Å resolution, yielding key insights into a potential mechanism of catalysis.  As well, a covalent bond between D277 and the FAD 8α methyl group was discovered. This is a novel post-translational modification that is likely conserved among a large subset of flavin dependent halogenases and raises interesting questions about the catalytic mechanism of flavin dependent halogenation.  Another key enzyme involved in the incorporation of the dichloroacetyl moiety into chloramphenicol is CmlK, an acyl-CoA synthetase.  Only through the tandem action of CmlS and CmlK enzymes will chloramphenicol be formed with its dichloroacetyl group.  A variety of activity assays were performed with CmlS and CmlK with the hope of discovering their substrate specificities.  However, in vitro reconstitution of the activity of CmlS or CmlK was not successful. Future studies are discussed which will hopefully lead to delineating the roles of CmlS and CmlK in the biosynthesis of the dichloroacetyl group, and ultimately a detailed mechanistic description of halogenation by CmlS.

abstract: M.Sc.


title: Diatom Assemblages in Relation to Water-Depth Gradients in Eight Boreal Shield Lakes From Northwestern Ontario, Canada

contributor:
Cumming, Brian F.
Biology

subject:
Paleolimnology
Diatoms
Ecology
Northwestern Ontario

abstract: Thesis (Master, Biology) -- Queen's University, 2010-07-23 12:36:01.347

abstract: The uncertainty surrounding the impact of future changes in climate and water resources has created renewed interest on how lakes have responded to drought in the past. There is a need to determine potential future available water by understanding past changes in water levels; the underlying ecological characteristics of using diatoms as a proxy for lake-level reconstructions is the basis of this thesis. By integrating knowledge from past water-level fluctuation studies and theories, along with developing a better understanding of diatom ecology in lake systems, more effective techniques are being developed to improve water-depth reconstructions. Diatom assemblages were examined from eight lakes in northwestern Ontario collected in surface sediments along a depth gradient at ~1-m water-depth intervals. Three major zones, based on the composition of diatom assemblages in each lake were consistently identified in all lakes: i) a near-shore assemblage of Achnanthes (sensu lato) species and other benthic taxa (Nitzschia, Cymbella); ii) a mid-depth small Fragilaria (sensu lato)/ small Aulacoseira zone with various Navicula taxa, and iii) a deep-water planktonic zone. The depths at which transitions between these zones are located varied among lakes, and the depth of the transition between the planktonic and benthic zones was consistent with water chemistry variables (e.g. DOC, TP) that are related to light attenuation. Deeper pelagic to benthic transitions occurred in lakes with the lowest DOC and TP (i.e. generally more light attenuation in lakes with higher concentrations of TP or DOC). Other findings included a decrease in species evenness and numbers with depth, along with an increase in scaled chrysophyte relative to diatoms.

abstract: M.Sc.


title: L'impact du cinéma dans le roman francophone d'Afrique noire

contributor:
Nshimiyimana, Eugene
French

subject:
cinema
africa
african novels
francophone literature

abstract: Thesis (Ph.D, French) -- Queen's University, 2010-07-23 13:33:45.297

abstract: In this thesis, I am interested in studying how African writers incorporate cinema in their works while focusing on the impact of Western and Asian films on the African public. My corpus includes writers such as Abdoulaye Sadji (Maïmouna), Ousmane Sembène (Les Bouts de bois de Dieu), Sylvain Bemba (Rêves portatifs), Tierno Monénembo (Cinéma), Henri Lopes (Le Pleurer-Rire) and Alain Mabanckou (African psycho and Verre Cassé). I use criticism by Freud, Barthes, Michel Foucault, Jean Bellemin-Noël, Christian Metz, Frantz Fanon, Achille Mbembe, Paulin Soumanou Vieyra and others to analyze, through the mechanisms of alienation, of depersonalization and corruption of the imaginary, the transmutation that cinema lovers in the African novel undergo. By « transmutation », I mean the process which leads to the expulsion of the individuality of some characters. This transformation will be manifested by an overactive imagination, by the exaltation of the most extravagant fantasies and by the violence inherent to the characters that now, in a perverse way, strive to reproduce in their social world the fictional world of movies that they have watched and which are fully disconnected from their environment. As these characters do not manage to draw the line that separates cinematic facts from their illusions, the narrative will suggest the confusion between cinema and "reality". Therefore, the loss of direction and other dealings will lead to personality disorders and criminal behaviors.

abstract: PhD


title: Investigating the Role of Reactive Oxygen Species in Benzoquinone-Mediated DNA Damage and Recombination in Fetal Hematopoietic Cells

contributor:
Winn, Louise M.
Pharmacology and Toxicology

subject:
Benzene
Reactive Oxygen Species
DNA Damage
DNA Recombination

abstract: Thesis (Master, Pharmacology & Toxicology) -- Queen's University, 2010-07-23 15:44:05.381

abstract:
Benzene is a ubiquitous environmental pollutant and a known human leukemogen. Early-life exposure to environmental carcinogens, including benzene, may lead to genomic instability in the fetus, ultimately leading to an increased risk for the development of childhood cancers including leukemia.  It is possible that exposure to benzene results in DNA damage that may either be left unrepaired or be repaired erroneously causing genotoxicity.
The first objective of this study was to determine if exposure of fetal hematopoietic cells to p-benzoquinone, a known toxic metabolite of benzene, increased DNA recombination in the pKZ1 model of mutagenesis. A significant increase in recombination was observed following exposure to 25 μM and 50 μM p-benzoquinone for 2, 4, 8, and 24 hours. A significant increase in recombination was also observed following exposure to 25 μM p-benzoquinone  for 30 min, 45 min, and 1 hour, but not 15 min as compared to vehicle alone.
Secondly, this study determined if exposure of fetal hematopoietic cells to p-benzoquinone resulted in DNA damage using γ-H2A.X as a marker for DNA double strand breaks and 8-hydroxy-2’-deoxyguanosine as a marker of oxidative DNA damage. A significant increase in γ-H2A.X foci formation was observed following exposure to 25 μM p-benzoquinone for 30 min, 45 min and one hour. Exposure of fetal hematopoietic cells to 25 μM p-benzoquinone did not significantly increase oxidative DNA damage at any of the examined time points.
The third objective of this study was to determine whether or not reactive oxygen species were involved in the observed increase in DNA damage and recombination. Exposure to 25 μM p-benzoquinone for 15 min and 30 min, but not 45 min or one hour, led to an increase in reactive oxygen species production as measured by 5-(and-6)-chloromethyl-2-7-dichlorodihydrofluorescein diacetate fluorescence. Additionally, pretreatment with 400 U/mL PEG-catalase, an antioxidative enzyme, attenuated the increases in both DNA recombination and DNA double strand breaks as compared to treatment with p-benzoquinone alone. These studies indicate that p-benzoquinone is able to induce DNA damage and recombination in fetal hematopoieitic cells and that reactive oxygen species and oxidative stress may be important in the mechanism of toxicity.

abstract: M.Sc.


title: Advanced Nonlinear Techniques for Low Cost Land Vehicle Navigation

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

subject:
Land Vehicle Navigation
Global Positioning System (GPS)
Inertial Navigation System (INS)
MEMS-based INS/GPS Integration
Particle Filter
Kalman Filter

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2010-07-23 20:27:02.12

abstract:
Present land vehicle positioning and navigation relies mostly on the Global Positioning System (GPS). However, in urban canyons, tunnels, and other GPS-denied environments, the GPS positioning solution may be interrupted or suffer from deterioration in accuracy due to satellite signal blockage, poor satellite geometry or multipath effects. In order to achieve continuous positioning services, GPS is augmented with complementary systems capable of providing additional sources of positioning information, like inertial navigation systems (INS).  Kalman filtering (KF) is traditionally used to provide integration of both INS and GPS utilizing linearized dynamic system and measurement models. Targeting low cost solution for land vehicles, Micro-Electro-Mechanical Systems (MEMS) based inertial sensors are used. Due to the inherent errors of MEMS inertial sensors and their stochastic nature, which is difficult to model, KF has limited capabilities in providing accurate positioning in challenging GPS environments.
This research aims at developing reliable integrated navigation system capable of demonstrating accurate positioning during long periods of challenging GPS environments.
Towards achieving this goal, Mixture Particle filtering (MPF) is suggested in this research as a nonlinear filtering technique for INS/GPS integration to accommodate arbitrary inertial sensor characteristics, motion dynamics and noise distributions. Since PF can accommodate nonlinear models, this research develops total-state nonlinear system and measurement models without any linearization, thus enabling reliable integrated navigation and mitigating one of the major drawbacks of KF. Exploiting the capabilities of PF, Parallel Cascade Identification (PCI), which is a nonlinear system identification technique, is used to obtain efficient stochastic models for inertial sensors instead of the currently utilized linear models, which are not adequate for MEMS-based sensors. Moreover, this research proposes a method to update the stochastic bias drift of inertial sensors from GPS data when the GPS signal is adequately received. Furthermore, a technique for automatic detection of GPS degraded performance is developed and led to improving the performance in urban canyons.
The performance is examined using several road test experiments conducted in downtown cores to verify the adequacy and the benefits of the methods suggested. The results obtained demonstrate the superior performance of the proposed methods over conventional techniques.

abstract: PhD


title: Changing Beliefs About Categories and Individual Instances: Evidence for the Moderating Effect of  Level of Representation

contributor:
Fabrigar, Leandre R.
Psychology

subject:
belief change
stereotype change
impression formation
persuasion
person perception
attitude change

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2010-08-18 12:33:26.718

abstract: This research program examined the implications of level of representation for the belief change process.  Specifically, it investigated whether representational level of information underlying initial beliefs (individual vs. category) and disconfirming information (individual vs. category) influences the magnitude of belief change about a variety of objects.  Chapter 2 examined the hypotheses for beliefs about categories.  In 3 experiments, two key effects emerged.  A main effect of type of disconfirming information indicated that category-level disconfirming information produced more belief and attitude change than individual-level disconfirming information.  Also, a significant interaction between type of information at formation and disconfirmation indicated a relative matching effect, with category-level disconfirmation producing substantially more belief and attitude change than individual-level disconfirmation when initial beliefs were based on category-level information, but only slightly greater change when initial beliefs were based on individual-level information.  Chapter 3 examined the hypotheses for beliefs about individual instances.  A main effect of type of disconfirming information indicated that individual-level information produced more belief and attitude change than category-level information.  A main effect of type of formation revealed that category-level formation was more susceptible to persuasion than individual-level formation.  Also, a significant interaction between type of information at formation and disconfirmation indicated a relative matching effect, with individual-level disconfirmation producing substantially more change than category-level disconfirmation when initial beliefs were based on individual-level information, but no difference when initial beliefs were based on category-level information.

abstract: PhD


title: The Influence of Sequence Variation on von Willebrand Factor Biosynthesis, Proteolytic Processing and Clearance

contributor:
Lillicrap, David
Pathology and Molecular Medicine

subject:
von Willebrand Factor
ADAMTS13
Hemostasis
Thrombosis
von Willebrand Disease
Bleeding
Clotting
Pathology

abstract: Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2010-07-28 10:24:40.654

abstract:
Von Willebrand factor (VWF) promotes platelet adhesion and aggregation at sites of vascular damage.  This function is directly related to the multimer size of VWF.  The VWF-specific metalloprotease ADAMTS13 decreases VWF multimer size by cleaving at Y1605-M1606 in the VWF A2 domain.
This thesis examined the sensitivity of ADAMTS13 cleavage to mutagenesis of the full-length multimerized VWF substrate, and a small VWF A2 domain fragment, VWF115.  The ADAMTS13 cleavage site at Y1605-M1606 was mutated with the most severe loss of cleavage observed in Y1605A/M1606A.  In addition, 4 single nucleotide polymorphisms were examined, with D1472H, Q1571H, P1601T proteins all showing increased resistance to cleavage.  In contrast, G1643S has enhanced cleavage in the full-length VWF substrate but shows cleavage resistance in VWF115.  Three von Willebrand disease mutations were also examined.  In patients, R1597W has enhanced ADAMTS13 cleavage and a loss of high molecular weight multimers, while R1205H has enhanced protein clearance resulting in very low VWF levels and Y1584C patients have moderately low VWF levels.  R1597W has enhanced cleavage of full-length VWF, while a slight cleavage increase is observed in VWF115 for Y1584C, and no change is seen with R1205H.
The VWF mutations R1597W, Y1605A/M1606A, R1205H and Y1584C were further examined in the VWF knockout mouse using recombinant VWF protein infusion and hydrodynamic delivery of VWF cDNA to determine the effects these mutations produce on VWF antigen levels, multimer structure, secretion, clearance and function in a thrombotic injury model.  All four mutations had different pathogenic mechanisms.  R1597W showed accelerated clearance with loss of multimer structure, and greatly increased time to thrombotic occlusion.  Y1605A/M1606A showed accelerated clearance with normal or supranormal multimer structure, a loss of thrombotic occlusion but increased platelet accumulation.  Y1584C showed no change in protein clearance, with decreased VWF antigen level, reduced multimer structure, and reduced thrombotic potential.  R1205H demonstrated a synthetic defect in vitro and in vivo increased clearance with a decrease in VWF antigen levels and normal multimer structure and a variable thrombotic potential.  These results validate the use of the genetically-modified VWF knockout mouse model for evaluating the pathogenic mechanisms of putative VWF mutations.

abstract: Twho chapters (chapters 3 and 4) are being submitted for publication.  We would like to wait until the acceptance of these publications for the thesis to be accessible.

abstract: PhD


title: Modelling Pathogen Evolution with Branching Processes

contributor:
Day, Troy
Mathematics and Statistics

subject:
Evolution
Infectious disease
Mathematical biology
Stochastic process
Multi-type branching process
Epidemiology

abstract: Thesis (Master, Mathematics & Statistics) -- Queen's University, 2010-07-28 11:43:22.984

abstract:
Pathogen evolution poses a significant challenge to public health, as efforts to control the spread of infectious diseases struggle to keep up with a shifting target.  To better understand this adaptive process, we turn to mathematical modelling.  Specifically, we use multi-type branching processes to describe a pathogen's stochastic spread among members of a host population or growth within a single host.  In each case, there is potential for new pathogen strains with different characteristics to arise through mutation.

We first develop a specific model to study the emergence of a newly introduced infectious disease, where the pathogen must adapt to its new host or face extinction in this population.  In an extension of previous models, we separate the processes of host-to-host contacts and disease transmission, in order to consider each of their contributions in isolation.  We also allow for an arbitrary distribution of host contacts and arbitrary mutational pathways/rates among strains.  This framework enables us to assess the impact of these various factors on the chance that the process develops into a large-scale epidemic.  We obtain some intriguing results when interpreted in a biological context.

Secondly, motivated by a desire to investigate the time course of pathogen evolutionary processes more closely, we derive some novel theoretical results for multi-type branching processes.  Specifically, we obtain equations for: (1) the distribution of waiting time for a particular type to arise; and (2) the distribution of population numbers over time, conditioned on a particular type not having yet appeared.  A few numerical examples scratch the surface of potential applications for these results, which we hope to develop further.

abstract: M.Sc.


title: What paves the road to maternal health care use? Investigating education, urban-rural residence, social-networks and supernatural beliefs in the Far-North province of Cameroon

contributor:
Moore, Spencer
Kinesiology and Health Studies

subject: Health Africa

abstract: Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2010-07-29 11:15:40.276

abstract: Every day, 1500 women die in pregnancy or due to childbirth related complications worldwide. Sub-Saharan Africa has the highest rates of maternal mortality. Maternal health care use is critical in reducing maternal mortality worldwide. Cameroon has one of the highest maternal mortality rates worldwide (over 1000 deaths per 100,000 live births), but there is little knowledge about maternal health care use in the Far-North province. The purpose of this study was to examine the role of education, urban and rural residence, social networks, and cultural beliefs on the use of maternal health care use in the Far-North province. A maternal health questionnaire was completed by 110 Cameroonian women between the ages of 18-45. Participants were recruited door-to-door in the urban town of Maroua and rural village of Moutourwa in the Far-North province. Questionnaires assessed maternal health care history, social networks and demographics. Follow-up interviews were conducted with nine questionnaire participants to gain a greater understanding of how daily activities, food consumption and beliefs in the supernatural impact maternal health care use. Poisson regression analyses were used to determine the association among education, social network characteristics, urban and rural residence, and maternal health care service use in Maroua and Moutourwa. Thematic analysis of semi-structured interviews revealed themes of witchcraft, diet and social ties. Women in the rural sample had a greater risk of failing to seek prenatal consultations than women in the urban sample (RR: 0.73; 95% CI: 0.61-0.88).  When stratified by urban/rural location, education played a greater role in women’s use of prenatal services in Moutourwa (RR: 0.69; 95% CI: 0.50-0.94) compared to Maroua (RR: 0.66; 95% CI: 0.41-1.06). Qualitative analyses suggested that beliefs in witchcraft may deter women from speaking about pregnancy, and that mothers often believe that envious women can cause harm to mother and child through the use of witchcraft. Social network analysis revealed that women who belonged to a women’s organization were more like to use prenatal services (RR: 1.31; 95% CI: 1.07-1.62). Both qualitative and quantitative findings have implications for maternal health interventions in the Far-North province of Cameroon.

abstract: M.Sc.


title: Aging and Sexual Offending: An Examination of Older Sexual Offenders

contributor:
Lindsay, Roderick C. L.
Psychology

subject:
Aging
Sexual Offending

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2010-07-29 11:40:51.234

abstract: This thesis examined the effect of age on sexually offensive behaviour. Research has noted both an increase in the average age of incarcerated offenders and that a higher percentage of older offenders are incarcerated for sexual offences than are younger offenders. Older sexual offenders were initially compared with younger offenders on offender and offence characteristics and these analyses revealed that older sexual offenders had a higher incidence of male victims, a younger victim age, and more intra-familial victims. Phallometric assessments of all sexual offenders were then examined to see whether sexual deviance may account for the differences found between older and younger sexual offenders in victim age and gender. These analyses revealed that the oldest and youngest offenders were more deviant than middle-aged sexual offenders and that the sexual interests of older offenders were more commonly for females. Finally, all subjects were classified as either Historical (offending had ceased, without judicial intervention, at least 7 years prior to incarceration), First-time (incarcerated for a recent sexual offence and no history of sexual offending), or Recidivist sexual offenders (currently incarcerated for a sexual offence and have at least one prior sentencing date for any sexual offence): age accounted for 12% of the variance in categorisation. Fifty-five percent of the sexual offenders age 60 years or more were found to have committed and ceased their offending at least seven years prior to incarceration (i.e., were Historical offenders). The percentage of Recidivist offenders remained relatively consistent across age groups at about 20%. No difference was found in phallometrically assessed sexual deviance between the groups of older offenders.

abstract: PhD


subject:
Houghton, Le Rossignol
Visionary Painting

abstract: Thesis (Ph.D, Art History) -- Queen's University, 2010-07-29 14:58:09.642

abstract: My dissertation, The Fringes of Immortality: A Goodly Company and Artistic Collaborations in Visionary Art 1880-1930 engages with fluctuating and often intermingling concepts of spirituality that took place in late-nineteenth and early-twentieth-century England. My discussion examines mediumistic visual representation inspired by interest in modern Spiritualism and modern Theosophy and takes the form of two case studies that focus on the work of visionary artists, Georgiana Houghton (1814-1884) and Ethel le Rossignol (1874 – 1970) both of whom believed that they were the recipients of information disclosed by disembodied entities. My study reconstructs possible meanings embedded in mediumistic images to disrupt longstanding artistic hierarchies that label visionary art as marginal.

abstract: PhD


title: Estimation and Effects of Imperfect System Parameters on the Performance of Multi-Relay Cooperative Communications Systems

contributor:
Blostein, Steven D.
Electrical and Computer Engineering

subject:
Synchronization
cooperative communications
timing offset
frequency offset
channel estimation
Cramer-Rao Lower Bound
capacity optimization
Modified Cramer-Rao Lower Bound
CRLB
MCRLB
parameter estimation

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2010-07-29 16:52:50.272

abstract:
To date the majority of research in the area of cooperative communications focuses on maximizing throughput and reliability while assuming perfect channel state information (CSI) and synchronization. This thesis, seeks to address performance enhancement and system parameter estimation in cooperative networks while relaxing these idealized assumptions.

In Chapter 3 the thesis mainly focuses on training-based channel estimation in multi-relay cooperative networks. Channel estimators that are capable of determining the overall channel gains from source to destination antennas are derived. Next, a new low feedback and low complexity scheme is proposed that allows for the coherent combining of signals from multiple relays. Numerical and simulation results show that the combination of the proposed channel estimators and optimization algorithm result in significant performance gains.

As communication systems are greatly affected by synchronization parameters, in Chapter 4 the thesis quantitatively analyzes the effects of timing and frequency offset on the performance of communications systems. The modified Cramer-Rao lower bound (MCRLB) undergoing functional transformation, is derived and applied to determine lower bounds on the estimation of signal pulse amplitude and signal-to-noise ratio (SNR) due to timing offset and frequency offset, respectively. In addition, it is shown that estimation of timing and frequency offset can be decoupled in most practical settings.

The distributed nature of cooperative relay networks may result in multiple timing and frequency offsets. Chapters 5 and 6 address multiple timing and frequency offset estimation using periodically inserted  training sequences in cooperative networks with maximum frequency reuse, i.e., space-division multiple access (SDMA) networks. New closed-form expressions for the Cramer-Rao lower bound (CRLB) for multiple timing and multiple frequency offset estimation for different cooperative protocols are derived. The CRLBs are then applied in a novel way to formulate training sequence design guidelines and determine the effect of network protocol and topology on synchronization parameter estimation. Next, computationally efficient estimators are proposed. Numerical results show that the proposed estimators outperform existing algorithms and reach or approach the CRLB at mid-to-high SNR. When applied to system compensation, simulation results show that application of the proposed estimators allow for synchronized cooperation amongst the nodes within the network.

abstract: I would like to restrict access to this thesis since some of the material available here is not published yet and, therefore, should not be available for viewing.

abstract: PhD


title: Centrifuge Modelling Study of Contrasting Structural Styles in the Salt Range and the Potwar Plateau, Pakistan

contributor: Geological Sciences and Geological Engineering

subject:
Centrifuge Modelling
Mechanical Stratigraphy
Salt Range
Potwar Plateua
Ramp Systems
Kalabagh Fault Zone
Northern Potwar Deformed Zone
Contrasting Structural Styles

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2010-07-29 19:42:25.027

abstract:
The ENE-trending Himalayan fold-thrust belt in Pakistan exhibits contrasting deformation styles both along and across the strike. The centrifuge modelling technique has been used to investigate these variations in structural style. For the purpose of modelling, the Salt Range and Potwar Plateau (SR/PP) stratigraphy has been grouped into four mechanical units. From bottom to top these are the Salt Range Formation, carapace unit (Cambrian-Eocene platform sequences), Rawalpindi Group, and Siwalik Group. These stratigraphic units of alternating competence, composed of thin layers of plasticine modelling clay and silicone putty, rest on a rigid base plate that represents the crystalline basement of the Indian plate. The models are built at a linear scale ratio of ~10-6 (1mm=1km) and deformed in a centrifuge at 4000g. The models are subjected to horizontal shortening by collapse and lateral spreading of a “hinterland wedge” which simulates overriding by the Himalayan orogen (above the Main Boundary Thrust).
	The models of the central SR/PP show that the accretionary wedge develops a prominent culmination structure with fault-bend fold geometry over the frontal ramp, while the eastern SR/PP is more internally deformed by detachment folds, fault-propagation folds and pop-up and pop-down structures. Model results show that the transition from fault-bend fold to detachment-fold and fault-propagation-fold geometry in the prototype may take place in a transfer zone marked by an S-bend structure (Chambal Ridge and Jogi Tilla) at the surface and the lateral ramp in the subsurface. Moreover, the models suggest that an oblique ramp below the Kalabagh strike-slip connecting the two frontal ramps below the Surghar Range and the central Salt Range developed similar structure that can be observed in the prototype.
	The model results also show that the Northern Potwar Deformed Zone may have been developed over ductile substrata due to the close similarity between the models and the prototype structures.
	The deformation style in the models illustrates the importance of mechanical stratigraphic and basement ramp systems in the evolution and the structural styles of the SR/PP.

abstract: Since I am working on publications fom my Master thesis, therefore, I would not like to publish my thesis online right away.

abstract: M.A.Sc.


title: Cooperative DVB-H: Raptor-Network Coding Protocols for Reliable and Energy Efficient Multimedia Communications

subject:
Raptor Codes
Fountain Codes
Raptor Coding
Fountain Coding
Network Codes
Network Coding
Digital Video Broadcasting - Handheld
DVB-H
Cooperative Communications
Energy-Efficient
Reliability
Cooperative Protocols
Wireless Communications
Multimedia Broadcast

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-08-03 19:45:54.943

abstract:
Reliable and energy-efficient delivery of multimedia to mobile terminals in dynamic networks is a very challenging problem. In this thesis, we focus on a cooperative extension to the Digital Video Broadcasting – Handheld (DVB-H) standard, forming a cooperative broadcast network whereby terminal-to-terminal cooperation creates a distributed form of multi-input-multi-output (MIMO) that supplements existing fixed network infrastructure.

First, we develop a novel and computationally-efficient hierarchical Markov model that is able to accurately perform a cross-layer packet error mapping between the physical and transport layers of the DVB-H/IPDC (IP DataCast) protocol stack. We then construct a discrete-event simulator in MATLAB® that incorporates all of the necessary modules to conduct dynamic multiterminal network simulations. Next, the convergence of cooperative wireless communication, Raptor application layer forward error correction (AL-FEC) and Network Coding (NC) is examined. Originally proposed for broadcasting over the Internet, the application of Raptor codes to wireless cooperative communications networks has been limited to date, but they have been mandated for use in DVB-H. Network coding is used to reduce energy consumption by opportunistically recombining and rebroadcasting required combinations of packets. Two novel coding-enabled cooperative relaying protocols are developed for multicast and multiple unicast file distribution scenarios that are transparent, fully distributed, and backwards compatible with today's systems. Our protocols are able to exploit several different forms of diversity inherent to modern wireless networks, including spatial diversity, radio interface diversity, and symbol diversity. Extensive simulations show that our protocols simultaneously achieve breakthroughs in network energy efficiency and reliability for different terminal classes and densities, allowing greatly improved user experiences.

abstract: M.A.Sc.


title: Topologies and Modelings of Novel Bipolar Gate Driver Techniques for Next-Generation High Frequency Voltage Regulators

contributor:
Liu, Yan-Fei
Sen, Paresh C.
Electrical and Computer Engineering

subject:
Voltage Regulators
Bipolar Gate Driver
Current Source Driver
Inductorless Gate Driver

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-07-30 14:06:04.003

abstract:
As is predicted by Moore’s law, the transistors in microprocessors increase dramatically. In order to increase the power density of the microprocessors, the switching frequency of the Voltage Regulator (VR) is expected to increase to MHz level. However, the frequency dependent loss will increase proportionally. In order to meet requirements of the next-generation microprocessors, three new ideas are proposed in this thesis.
The first contribution is a new bipolar Current Source Driver (CSD) for high frequency power MOSFET. The proposed CSD alleviates the gate current diversion problem of the existing CSDs by clamping the gate voltage to a flexible negative value during turn off transition. Therefore, the proposed driver turns off the MOSFET much faster. For buck converters with 12 V input at 1MHz switching frequency, the proposed driver improves the efficiency from 80.5% using the existing CSD to 82.5% at 1.2V/30A, and at 1.3V/30A output, from 82.5% to 83.9%.
The second contribution is an accurate analytical loss model of a power MOSFET with a CSD. The current diversion problem that commonly exists in CSDs is investigated mathematically. The inductor value of the CSD is optimized to achieve minimum loss for the synchronous buck converter. The experimentally measured loss matches the calculated loss very well. The efficiency with the optimal CSD inductor is improved from 86.1% to 87.6% at 12V input, 1.3V/20A output in 1MHz switching frequency and from 82.4% to 84.0% at 1.3V/30A output.
The third contribution is a new inductorless bipolar gate driver for control FET of buck converters. The most important advantage of the driver presented in this thesis is that it can turn off the power MOSFETs with a negative voltage, which will significantly reduce the turn off time and thus switching loss. In addition, the proposed bipolar gate driver has no inductor in the driver circuit; therefore it can be fully integrated into a chip. For buck converter with 5V input, 1.3V/25A load, in 2 MHz frequency, the proposed gate driver increases the efficiency from 75.8% to 77.8% and from 72.9% to 76.5% at 5V input, 1.3V/25A load, in 2.5 MHz switching frequency.

abstract: M.A.Sc.


title: Predicting Youth Sexual Deviance: The Case of Risky Sexual Behaviour among Adolescents in Ghana

contributor:
Gyimah, Stephen O.
Baron, Stephen W.
Sociology

subject: Risky sexual behaviour, sexual deviance, adolescents, Ghana

abstract: Thesis (Master, Sociology) -- Queen's University, 2010-07-31 02:18:09.013

abstract:
ABSTRACT
 Although sub-Saharan Africa continues to bear the brunt of the global HIV/AIDS pandemic and other sexually transmitted diseases (UNAIDS and WHO 2008; Fatusi and Wang 2009), very few studies in the region and for that matter Ghana have systematically and exclusively examined adolescent risky sexual behaviour in a manner that is theoretically consistent with the unique socio-cultural norms that govern sexuality in the society.  Given that involvement in risky sexual behaviour constitutes sexual deviance in the Ghanaian context, and from the ontological position that behaviour is a product of structure and human agency (Sewell 1992), this study extends the theories of social control (Hirschi 1969), power control (Hagan et al. 1979, 1985,1987, 2002; McCarthy et al. 1999) and rational choice (Cornish and Clarke 1986) in examining the predictors of risky sexual behavior among Ghanaian adolescents. Using the 2004 Ghana National Adolescent Survey data (N=3985), the study employs descriptive statistics, measures of association and complementary log-log regression models in predicting the likelihood of being sexually active before marriage, having more than one lifetime sexual partner and  condom use.
Overall findings provide mixed support for the theoretical expectations. From the perspective of Hirschi’s control theory, the findings suggest among others that while some measures of conventional behaviour do not discourage premarital sex, they do so with respect to multiple sexual partnerships. A puzzle that needs further elaboration is the finding that highly educated adolescents who hold leadership positions have a higher significant taste for premarital sex and multiple sexual relations than their uneducated counterparts who are not leaders. Overall findings regarding the predictions of power control theory are consistent with the revised version offered by McCarthy and Colleagues (1999) and Hagan and colleagues (2002); that daughters in less patriarchal or matriarchal households are more likely than sons to have premarital sex and be in multiple sexual partnerships. Findings regarding the predictions of rational theory suggest a mixed rationality; condom use among adolescents in many instances is inconsistent with rational choice behaviour.  General and specific policy implications of the findings and direction for future research are also discussed.

abstract: M.A.


title: Hispanic (Hybridity) in Canada: The Making and Unmaking of a Diaspora

contributor:
Srivastava, Sarita
Krull, Catherine
Sociology

subject:
Hispanic
Diaspora
Ethnic media
Hybridity
Ethnic identity
Third Space
Immigrants
Ethnic minorities

abstract: Thesis (Master, Sociology) -- Queen's University, 2010-08-03 14:10:08.16

abstract: Ethnic media are powerful, and yet overlooked, spaces that immigrants and ethnic minorities establish to address issues that are not discussed in the dominant host society media. With the international migration of over five million people each year from majority to minority world nations, the emergence of ethnic media in countries around the world has increased significantly; however, relatively little is understood about the ways in which these spaces are used by immigrants and ethnic minorities. This thesis adds to a relatively new area of study in sociology, international development, and alternative media studies and investigates the ways in which Spanish-language ethnic media acts as a ‘Third Space’ where Hispanics disseminate, negotiate, (re)construct, and (re)articulate new notions of hybrid Hispanic-Canadian identity, an identity that operates against, and engages with, multiple-forms of difference and exclusion within Canada. A qualitative discourse analysis of 18 articles from Spanish-language ethnic media source El Correo Canadiense reveals the ways in which Hispanics in Canada negotiate hybridized identity by using ethnic media as a space to create a discourse that acts counter-hegemonically to Canadian mass-media. The findings also reveal the ways in which Hispanics are aiming to engage Canadians in the process of de- and re-constructing preconceived notions of what it means to “be Hispanic” in a transnational context.

abstract: M.A.


title: Functional Magnetic Resonance Imaging of Peripheral Neuropathic Pain in the Spinal Cord and Brainstem

contributor:
Stroman, Patrick W.
Cahill, Catherine M.
Neuroscience Studies

subject:
fMRI
neuropathic pain
spinal cord
brainstem
carpal tunnel syndrome

abstract: Thesis (Master, Neuroscience Studies) -- Queen's University, 2010-08-03 14:46:01.7

abstract:
To date, most studies investigating the neural signature of pain in humans have focused on the brain, and those studies concerned with more caudal areas (such as the spinal cord (SC) or brainstem) have used only experimental models of pain.  The objectives of this study were 1) to determine the neural activity in the human brainstem and SC that is caused by a noxious mechanical stimulus and 2) to compare the neural response to noxious stimuli in healthy controls and a patient population diagnosed with peripheral neuropathic pain.  The SC and brainstem contain important synaptic points in several major pain pathways, and comparing the neural response between a control and patient population in these areas provides a more complete picture of healthy and pathological pain processing.
Functional MRI studies of the SC and brainstem were carried out in healthy control subjects and patients diagnosed with carpal tunnel syndrome (CTS) in a 3T Siemens Magnetom Trio.  Subjects reported the point at which the pressure (in mmHg, applied to the wrist at the location of the median nerve) corresponded to a pain level of 2, 4, and 6 on a numerical 11 point pain scale.  Spatially normalized group results superimposed on anatomical templates in the axial orientation were visually identified using several stereotaxic atlases.
We observed consistent signal intensity change in areas implicated in the transmission and modulation of pain in both control and CTS groups.  Both groups showed a similar decrease in signal change with increasing pain, as results at pain level 2 are predominantly positive signal change and at pain level 6 are typically negative.  This may indicate a reduction in the tonic inhibition of painful sensations.  Differences between groups were readily visible in regions anatomically consistent with the dorsal horn (DH) of the cervical SC, rostral ventromedial medulla (RVM), dorsolateral pontine tegmentum (DLPT), and midbrain periaqudectal gray (PAG).  The anatomical variation in signal change between groups may represent, for the first time, a visualization of the functional difference between healthy and pathological pain processing in the SC and brainstem using spinal fMRI.

abstract: M.Sc.


title: The combined effects of sensory and non-sensory variables on saccade selection processes in visual search

contributor:
Dorris, Michael C.
Paré, Martin
Neuroscience Studies

subject:
Neuroscience
Vision
Decision Making
Reward
Visual Search

abstract: Thesis (Master, Neuroscience Studies) -- Queen's University, 2010-08-03 22:22:15.825

abstract:
Decisions are based on multiple sources of information. For example, sensory information encoding environmental features may be combined with prior experience to bias judgements in visual behaviour. With the goal of characterizing the rules by which sensory and non-sensory variables combine to direct saccade selection processes monkeys were trained in a visual search task where the discriminability of a visual target and reward outcome for correct foveation varied systematically. Target discriminability was manipulated across three levels of luminance contrast while reward was manipulated by 'tagging' a spatial location such that target foveation at the tagged location yielded one, two or four times the liquid reward available at all other locations. The location and discriminability of the search target amongst seven distractor stimuli varied randomly from trial-to-trial while the magnitude of reward at the tagged location was fixed for each experimental block.
Reward was found to have a large effect on search behaviour when target discriminability was low, but as discriminability increased, the effect of reward diminished. More specifically, reward increased choice probability and reduced the latency of saccades to target and distractor stimuli appearing in the tagged location. Together, the results suggested the effects of reward and luminance on saccade selection were dependent on one another.
To characterize the nature of this interaction search psychophysics were couched in saccade selection processes using signal detection theory. Signals carrying target and distractor related information were modelled and taken to capture an actual discrimination process implemented by the brain. It was found that a response bias in saccade selection processes could largely reproduce monkey choice behaviour for both correct and incorrect trials.

abstract: M.Sc.


title: A diatom-based paleolimnological study of water-quality changes related to multiple anthropogenic stressors in Lake Simcoe

contributor:
Smol, John P.
Biology

subject:
Paleolimnology
Water Quality
Diatoms
Lake Simcoe

abstract: Thesis (Master, Biology) -- Queen's University, 2010-08-04 12:03:42.267

abstract:
Freshwater systems in Canada are affected by a multitude of environmental stressors, including cultural eutrophication, introduction of non‐native species, and
climate change. Multiple stressors can interact in unpredictable ways and generate
novel ecological scenarios, thus creating challenges for lake management. Lake
Simcoe is an example of an aquatic system impacted by multiple stressors, facing
management challenges of deteriorating water quality and coldwater fisheries. In order to better understand stressor interactions and pre‐disturbance lake conditions, a long‐term perspective is necessary. Therefore, this study used paleolimnological techniques to assess changes in the water quality of Lake Simcoe over the past ca. 200 years. Sedimentary diatom assemblages were analyzed in 210Pb‐dated cores from five sites across the lake. Diatom assemblages recorded
several pronounced and synchronous shifts over the last ca. 200 years. Modest lake‐wide shifts in diatom community composition occurred in the late‐1800’s and early‐1900’s, suggesting that early cultural disturbances, such as land clearance and canal construction, had relatively minor impacts on Lake Simcoe. However, starting in the 1930’s, agricultural and urban development intensified, as indicated by substantial increases in eutrophic taxa. The most pronounced lake‐wide shift in diatom assemblages occurred in the mid‐to‐late 1900’s, the taxonomic nature and timing of which strongly suggest a response to regional climate warming.
Moreover, diatom compositional trends at all sites were significantly correlated with
instrumental records of regional temperature and lake ice the last ca. 100 years. An
additional and marked lake‐wide shift in diatom assemblages occurred in the mid-1990’s, coinciding with the invasion of dreissenid mussels. The combination of
stressors acting concurrently on Lake Simcoe, as well as the lake’s distinct water
chemistry and size, make it challenging to reconstruct single limnological variables
(such as, total phosphorus) in this system. Nevertheless, overall patterns of diatom
compositional changes from the five sites revealed the largest shifts occurred in the
post‐1950 sediments and that change in lake‐water total phosphorus concentrations
played a minor role. Our results imply that substantial changes in climate have
amplified the effects of multiple stressors in this complex system.

abstract: M.Sc.


title: Psychache and Self-Harming Behaviour Among Men Who Are Homeless: a Test of Shneidman's Model

contributor:
Holden, Ronald R.
Psychology

subject: Homelessness Suicide

abstract: Thesis (Master, Psychology) -- Queen's University, 2010-08-05 17:49:11.178

abstract: Suicidal ideation among the homeless is 10 times greater than in the general population. Therefore, research helping mental health professionals better predict and potentially prevent suicide within the homeless population is an important societal focus. Various cognitive theories of depression and hopelessness have been proposed to explain suicidality, however, to date, none of these are able to fully explain the phenomenon. More recently, Shneidman has suggested a theory of psychache (i.e., unbearable psychological pain) to explain suicidality. Although this theory has been supported by investigations with university students, there has not been much research exploring psychache with populations at high risk for suicide. The current study attempts to assess Shneidman’s theory with a high risk population, namely the homeless. Ninety-seven men were recruited at homeless shelters and drop-in centres. Participants completed questionnaires assessing criterion measures of suicidality and psychological predictors of depression, hopelessness, life meaning, and psychache. Analyses revealed that psychache was the only variable with statistical predictive ability over and above the other three psychological variables in predicting suicide ideation, motivation, preparation, and attempt history. This finding indicates that psychache is a better predictor of suicidality than depression, hopelessness, and life meaning and supports Shneidman’s model of psychache as the most proximal cause of suicide. Results also indicate the potential use of a scale assessing psychache in mental health settings to predict those who are, and are not, at risk for suicide.

abstract: M.Sc.


title: The Impact of Agricultural Practices on Environmental Health: A Comparative Analysis in India

contributor:
van Loon, Gary
Environmental Studies

subject:
Agriculture
Environmental Health
India
Sustainable development

abstract: Thesis (Master, Environmental Studies) -- Queen's University, 2010-08-04 18:17:42.911

abstract:
There is growing evidence of multiple links between human health and the practice and products of agriculture through a complex set of factors including environmental change, exposure to a variety of natural and human-origin stressors, social position, changing behavior, occupation, and access to services. However, in policy initiatives, agriculture and health are often pursued in an unconnected manner. In India’s context, this has immense significance as nearly seventy percent of the total population is involved directly or indirectly with agriculture. The need to be aware of the health implications is therefore especially important.
The objective of the study was to examine the changing agricultural scenario in India and the consequences for health. A survey was carried out in 2009, in six villages in Karnataka state, India.  The data were collected by in-depth interviews, focus groups discussion, participant observation, laboratory tests (mercury and pesticide residues in rice, and nitrate and fluoride in groundwater) and secondary materials.
India has undergone a rapid transformation in agriculture and has achieved remarkable success in food production. The nation has followed the strategies of the popular ‘Green Revolution’, including promotion of high yielding seeds, monoculture, extensive use of agrochemicals and large scale management of land and water resources.
Modern agriculture has improved the socioeconomic and nutritional status of the population. However, the traditional coarse cereals and pulses have been replaced by mill-polished less nutritious rice. Extensive mechanization of agriculture activities has meant reduced physical stress, but fatal accidents and injuries have increased considerably. Along with already existing malnutrition, overweight/obesity has emerged as a new public health challenge. The changing landscape with much standing water and extensive use of nitrogen and phosphate fertilizer has augmented the mosquito population, resulting in greater incidence of vector borne diseases such as malaria and Japanese encephalitis. Agrochemicals, fertilizers and pesticides, are applied in excess and often in an irrational manner, without following any norms. Drinking water is contaminated with nitrate and fluoride. Rice samples contain pesticide residues and mercury.

abstract: M.E.S.


title: Cellular Mechanisms Involved in Stress-Induced Coma and CNS Spreading Depression in the Locust

contributor:
Robertson, Mel
Biology

subject:
Anoxia
Central Pattern Generator
Coma
Locust
Potassium
Spreading Depression
Ventilation

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2010-08-05 16:08:19.905

abstract: Spreading depression (SD) is an interesting and important phenomenon due to its role in mammalian pathologies such as migraine, seizures, and stroke.  Until recently investigations of the mechanisms involved in SD have mostly utilized mammalian cortical tissue, however in my thesis I demonstrated that SD-like events occur in the CNS of an invertebrate model, Locusta migratoria.  Locusts enter comas in response to stress during which neural and muscular systems shut down until the stress is removed, and this is believed to be an adaptive strategy to survive extreme environmental conditions.  Using the ventilatory central pattern generator (vCPG) as a model circuit I was able to show that stress-induced arrest of vCPG function is associated with SD-like events in the locust metathoracic ganglion (MTG) that closely resemble cortical SD (CSD) in many respects, including mechanism of induction, extracellular potassium ion ([K+]o) changes, and propagation in areas equivalent to mammalian grey matter.  SD-like events in the locust were characterized as abrupt [K+]o increases associated with electrical activity silence in the locust CNS that propagate to other areas within the MTG.  In this thesis I described the generation of comas by several cellular stressors (hyperthermia, metabolic stressors, Na+/K+-ATPase inhibition, and KCl) and the associated SD-like events in the locust, provide a description of the similarities to CSD, and show how they can be manipulated both by stress preconditioning and pharmacologically.  I showed that hyperthermic vCPG arrest can be preconditioned by prior heat shock (HS) treatment and induced-thermotolerance was associated with an increased rate of [K+]o clearance associated with vCPG recovery that was not linked to changes in ATP levels or total Na+/K+-ATPase activity.  I also provided evidence for the involvement of the stress-sensor AMP-activated protein kinase (AMPK) in stress-induced comas in the locust.  AMPK activation was linked to a switch in motor pattern behavior following recovery from anoxia-induced vCPG arrest and exacerbated repetitive SD-like events induced by ouabain (Na+/K+-ATPase inhibitor).  I suggested that locust SD-like events are adaptive by conserving energy and preventing cellular damage, and I provided a model for the mechanism of SD onset and recovery in the locust nervous system.

abstract: PhD


title: Advancing the Theory and Utility of Holographic Reduced Representations

contributor:
Mewhort, Douglas J. K.
Blostein, Dorothea
Computing

subject:
Holographic Reduced Representations
HRRs
Associative Memory
Cognitive Modelling
Reduced Representation
Square Matrix Memory

abstract: Thesis (Master, Computing) -- Queen's University, 2010-08-10 12:50:04.004

abstract: In this thesis, we build upon the work of Plate by advancing the theory and utility of Holographic Reduced Representations (HRRs). HRRs are a type of linear, associative memory developed by Plate and are an implementation of Hinton’s reduced representations. HRRs and HRR-like representations have been used to model human memory, to model understanding analogies, and to model the semantics of natural language. However, in previous research, HRRs are restricted to storing and retrieving vectors of random numbers, limiting both the ability of HRRs to model human performance in detail, and the potential applications of HRRs. We delve into the theory of HRRs and develop techniques to store and retrieve images, or other kinds of structured data, in an HRR. We also investigate square matrix representations as an alternative to HRRs, and use iterative training algorithms to improve HRR performance. This work provides a foundation for cognitive modellers and computer scientists to explore new applications of HRRs.

abstract: M.Sc.


title: Control of Cytochrome c Oxidase Biosynthesis in the Thermal Remodeling of White Muscle of Two Cyprinid Minnows

contributor:
Moyes, Christopher D.
Biology

subject:
Cytochrome c oxidase
Thermal Remodeling
Mitochondria

abstract: Thesis (Master, Biology) -- Queen's University, 2010-08-10 11:35:35.352

abstract:
Many fish species respond to cold temperatures by inducing mitochondrial biogenesis, reflected in an increase in the activity of the mitochondrial enzyme cytochrome c oxidase (COX). COX is composed of 13 subunits, 3 encoded by mtDNA and 10 encoded by nuclear genes. I used thermal acclimation/winter acclimatization to explore how fish muscle controls the synthesis of COX. In this study, I used real-time PCR to measure mRNA levels for the 10 nuclear-encoded COX genes and several transcriptional regulators. I compared the thermal response of two cyprinid species, the tropical zebrafish (Danio rerio, acclimated to 11 and 30°C) and the temperate redbelly dace (Phoxinus eos, winter and summer acclimatized). I hypothesized that (i) there would be an increase in COX activity in the cold- versus warm-acclimated fish and (ii) changes in COX activity would be paralleled in the transcript levels of the nuclear-encoded COX subunits as well as the master-regulators and transcription factors of mitochondrial biogenesis.
Zebrafish COX activity did not change in the cold but the transcript levels of some subunits decreased up to 70%. Redbelly dace COX activity was 2.9-fold higher in winter fish and though nuclear-encoded subunits had higher transcript levels the increases did not parallel enzyme activity, ranging from 1.7- to 21-fold higher in winter. There also did not appear to be parallel patterns in mRNA for the transcriptional regulators.  In zebrafish, when COX activity did not change, there was no significant change in PGC-1α mRNA.  In redbelly dace, when COX activity was 2.9-fold higher, PGC-1α mRNA was 6.3-fold higher. These observations suggest that coordination of COX subunit expression is imperfect, implying that subsets of these genes are more important in determining the COX activity. I assert that those genes that are most likely the candidates for regulating COX activity are COX4 and COX5A as they are the first regulatory subunits incorporated into the holoenzyme. Though arguments can also be made for COX5B, 6A and 7B based on the parallels between changes in enzyme activity and transcript abundance as well as the position in which they are assembled into the enzyme complex.

abstract: M.Sc.


title: Extraversion and Self-Monitoring: Exploring Differential Responses to Descriptive and Injunctive Normative Messages within the Framework of the Elaboration Likelihood Model of Persuasion

contributor:
Fabrigar, Leandre R.
Psychology

subject:
Social Influence
Persuasion

abstract: Thesis (Master, Psychology) -- Queen's University, 2010-08-10 14:32:21.064

abstract: The purpose of this research program was to explore how the personality traits of extraversion and self-monitoring may impact a persuasive appeal within the framework of the Elaboration Likelihood Model of persuasion. Using both descriptive and injunctive normative messages, I hypothesized that under conditions of low elaboration, when one is unable and unmotivated to process a message; those high in the traits of extraversion and self-monitoring would be more compliant to a persuasive appeal that utilized a descriptive normative message. Further, I hypothesized that under conditions of low elaboration, those low in the aforementioned traits would be more compliant to an appeal utilizing injunctive normative messages. I did not expect to find any differences relating to personality under conditions of high elaboration. In order to examine these expected interactions, I pre-tested messages to ensure they were adequately descriptive or injunctive (study one) and then presented these messages to participants who had previously completed measures of extraversion and self-monitoring (study two). In study one I successfully created both injunctive and descriptive normative messages that were adequately divergent. In study two, I manipulated elaboration by giving participants in the low elaboration condition a distracter task while they were reading the message, and by reducing personal relevance of the message, whereas for those in the high elaboration condition, there were no distractions and personal relevance was high. Contrary to predictions, I did not find the expected three-way interactions between extraversion, message type, and elaboration or self-monitoring, message type, and elaboration. However, I did find evidence supporting a two-way interaction between message type and elaboration, suggesting that descriptive messages are more persuasive under conditions of low elaboration whereas injunctive messages are more persuasive under conditions of high elaboration. Explanation for these findings, as well as implications of the findings both theoretical and practical, will be discussed in terms of the persuasion literature.

abstract: M.Sc.


title: Role of Amplification of Chromosome 6P12-P21 in Human Osteosarcoma

contributor:
Squire, Jeremy A.
Pathology and Molecular Medicine

subject:
Osteosarcoma
Cytogenetics
Fluorescence In Situ Hybridisation
RUNX2

abstract: Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2010-08-13 09:07:19.59

abstract: Osteosarcoma is an aggressive bone malignancy with neither reliable prognostic or predictive biomarkers nor drugs for targeted therapy. It is the most common malignant tumour of bone, predominantly occurring in adolescents. Currently, the mainstay of treatment is surgical resection in combination with multi-agent chemotherapy. Understanding of the genetic basis of osteosarcoma has been impeded by the complex and heterogeneous nature of genome-wide rearrangements in tumour cells. It has been shown that the genetic complexity arises as a result of unusually high levels of chromosomal instability (CIN), which causes numerous copy number changes. This extensive CIN leads to genomic gains or amplifications of various chromosomal regions including, frequently, a portion of chromosome 6 between cytobands 6p12-p21. The high frequency of these particular rearrangements implies they could confer selective advantage to tumour cells during osteosarcoma development. In the present study, we examined the relationship between genomic gain of chromosome 6p12-p21, including increased copy number of the osteogenic transcription factor gene RUNX2, and measures of CIN as well as tumour response to chemotherapy in a retrospective cohort of osteosarcoma patients. The present study demonstrates: 1) Gain and amplification events involving chromosome 6p12-p21 have been frequently reported in a variety of cancer types in addition to osteosarcoma. 2) Clusters of segmental duplications greater than 10,000 base pairs in length flank the commonly amplified region of 6p12-p21, and cytobands 6p12 and 6p21.3 are enriched in highly similar segmental duplications. 3) Interphase fluorescence in situ hybridisation (FISH) confirmed array comparative genomic hybridisation-detected copy number changes in E2F3, PIM1, and RUNX2 and identified trends between increased RUNX2 copy number and poor tumour response to chemotherapy, and between increased E2F3 copy number and CIN. 4) Interphase FISH for chromosome-specific enumeration identified a high rate of aneuploidy in the sample set. 5) Moderate to strong RUNX2 immunoreactivity, as assessed by immunohistochemistry, was present throughout the samples, and a trend was observed between high RUNX2 levels and poor tumour response to chemotherapy. Our study thus identified potential roles for genomic gain of chromosome 6p12-p21 and amplification-related overexpression of RUNX2 in the development of osteosarcoma and in resistance to chemotherapy.

abstract: M.Sc.


title: The Roles of School Climate and Peers in Bullying

contributor:
Craig, Wendy M.
Psychology

subject:
Bullying
Victimization
School climate
Program evaluation

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2010-09-21 11:33:00.394

abstract:
Bullying is a serious and common problem in Canadian schools. Despite three decades of comprehensive research on this complex behavioural problem, much remains to be understood. The general purpose of the current studies was to comprehensively examine bullying from an ecological perspective and the roles that school climate and peer processes play in the development of this behaviour, in order to elucidate mechanisms for intervention. The first study was a multilevel analysis of the relative importance of individual and school characteristics in bullying in Canadian schools. In a second study, we examined the experiences of peers who witnessed bullying incidents in order to investigate whether there were factors that predicted a decrease in witness behaviour. Finally, we conducted an evaluation of a peer-mediated bullying prevention program using a pre/post controlled study design. We assessed the impact of this program on behaviour, socioemotional skills, and school climate. Overall, our findings were consistent with the view that bullying is a problem of destructive relationships that needs to be addressed from this perspective. We found that relationships among peers and adults at school contributed to the overall climate of a school, and an overall climate of peer connectedness was associated with less bullying. Provictim attitudes and emotional supportiveness predicted change in bystander behaviour, although the nature of these changes differed for boys and girls. Finally, we did not find evidence of an effect of the prevention program on bullying behaviour or school climate, and we discuss the lack of findings with regard to program implementation and future program evaluations.
	This research has implications for understanding the influence of peers and peer group processes on the development of bullying. It is our hope that these studies will contribute important information to the bullying literature to expand our knowledge of the ways in which school climate and peers affect and are affected by bullying and victimization. In turn, this information may help to inform intervention efforts and encourage future program evaluation research and research examining the mechanisms by which we might mobilize peers to behave in ways that could help to stop bullying and victimization.

abstract: PhD


title: Make This Your Home: The Impact of Religion on Acculturation: The Case of Canadian Khoja Nizari Isma'ilis from East Africa

subject: Religion Isma'ili Acculturation Immigration Canada

abstract: This study examines the impact of religion on acculturation in a specific community, using the framework presented by Berry. Working from a Canadian perspective, Berry has created a framework that unifies much of the existing research, taking into account factors that impact acculturation prior to migration, such as education, economic status, gender roles, and migration expectations, as well as factors that arise during the acculturative process, such as the views of the new society towards migrants, the acculturation strategy chosen, and the phase of migration. This study uses rich, qualitative data from interviews, supplemented by primary and secondary source material, to focus on a religious community, the Khoja Nizari Isma‘ilis from East Africa, who have immigrated to a Canadian setting and appear to have acculturated quite successfully here. Findings demonstrate that religion, including community structures, social resources, and guidance from their Imam, have had a profound and positive impact on the acculturation of Khoja Nizari Isma‘ilis from East Africa in Canada. It is hoped that this case will help to fill gaps in the existing body of research and encourage scholars to consider the impact that religion may have as a unique category when considering acculturation, and prompt its inclusion along with the other factors, such as those proposed by Berry, rather than having it subsumed under them, as has typically been the case.


title: Daoism in Brazil: The Globalization of the Orthodox Unity (Zhengyi) Tradition

subject:
Daoism
Taoism
Brazil
Religion
Globalization
Rio de Janeiro
Sao Paulo
Orthodox Unity
Zhengyi

abstract:
The Daoist Society of Brazil (Sociedade Taoista do Brasil) was founded by Wu Jyh Cherng (Wu
Zhicheng 武志成), a Taiwanese immigrant, in 1991. Today the Society operates two temples in
Rio de Janeiro and São Paulo, and is the only religious organization in South America that is
affiliated with the Daoist Society of China in the Orthodox Unity (Zhengyi 正一) lineage. The
group, however, is not made up of other immigrants or Brazilians of Chinese descent; rather the
entire group and current priesthood consist of Brazilians of non-Chinese ancestry.
This essay examines the history and development of the Daoist Society of Brazil and its
members’ understandings of Daoism through site visits and interviews conducted in December
2009. From this I develop a theory of the particular characteristics of Brazilian religious culture
that enabled the formation of a Zhengyi Daoist community outside of ethnically Chinese people.
The practices of the two temples thus represent a hybrid of Chinese and Brazilian cultural forms
that have been negotiated through a complex assessment of how to maintain authentic religious
traditions in a non-traditional cultural context. Although the transcultural practices of the Daoist
Society of Brazil can only be fully understood in these particular terms, the Society also
represents an important case study in the more general phenomenon of the globalization of
religious cultures and the formation of transcultural religious identities.


title: Transhumanism as a Religious Product of the West: A Comparative Analysis with Christianity

subject:
Eschatology
Transhumanism
Comparative Method
Comparison
Soul
Mind
Christianity
Religion
Technology
Millenarianism
Sacred
Identity
Secularization

abstract: This project examines transhumanism and its historical relationship to Christianity in the West. Through a comparison of the eschatologies of transhumanism and Christianity this project argues that transhumanist ideas which espouse the inevitability of mechanical life and the immortalization of the human mind are akin to a particular understanding of Christian eschatological belief. In doing this comparison, this project demonstrates that transhumanist theories of the future state of humanity may in fact be religious extensions of Christian apocalyptic traditions in the West. A central basis of this eschatological comparison between these two worldviews includes the equation of the transhumanist understanding of the mind with particular Christian understandings of the soul. This venture entertains the idea of conceiving transhumanism as a religion and as such discusses some potential implications of this conception. An analysis of the comparative method in this case is also discussed.


title: Regulation of the MexAB-OprM Multidrug Efflux System of Pseudomonas aeruginosa: Involvement of Pentachlorophenol and Plant Chemicals

contributor:
Poole, R. Keith
Microbiology and Immunology

subject:
Multidrug efflux
Antimicrobial resistance
Pseudomonas aeruginosa

abstract: Thesis (Master, Microbiology & Immunology) -- Queen's University, 2010-09-10 10:35:16.271

abstract: Pseudomonas aeruginosa is a common soil organism as well as an opportunistic human pathogen. Treatment of P. aeruginosa infections is often complicated by innate resistance to a variety of antimicrobials mediated by multidrug efflux systems. The MexAB-OprM efflux system is constitutively expressed in wildtype strains and contributes to innate antimicrobial resistance, while hyperexpression of the system results in acquired high levels of resistance. MexAB-OprM is hyperexpressed in nalC mutants containing mutations in the gene encoding NalC, a repressor of a two-gene operon, PA3720-armR. armR encodes a protein modulator of MexR, a repressor of mexAB-oprM expression. Previous reports showed that genes encoding the MexAB-OprM efflux system are upregulated in response to pentachlorophenol (PCP), a phenolic compound that is a common environmental contaminant. Induction of mexAB-oprM and PA3720-armR by PCP was confirmed using RT-PCR, and MexAB-OprM was shown to be involved in PCP resistance. An electromobility shift assay (EMSA) showed that PCP interacts with NalC, interfering with its binding to the PA3720-armR promoter region and thereby promoting PA3720-armR expression.  Nonetheless, the increase in ArmR did not drive mexAB-oprM expression suggesting that PCP induction of this efflux operon occurred via a different mechanism. A direct PCP-MexR interaction could not be demonstrated using an EMSA. PCP exposure did, however, reduce expression of nalD, encoding a second repressor of mexAB-oprM, which might explain the PCP-promoted increase in mexAB-oprM expression. PCP is unlikely to be the intended inducer(s)/substrate(s) for this system but probably resembles these. Several compounds related to PCP were tested for an interaction with NalC but all were negative in EMSAs. Plants produce a variety of phenolic compounds, which are often antimicrobial and, so, root extracts of various plants were tested for an ability to interact with NalC and interfere with promoter binding.  Extracts from Boehmeria tricuspis, Uncaria tomentosa and Ixiolirion tataricum were shown to interact with NalC, suggesting that plant compounds may be the intended inducers/substrates for NalC/MexAB-OprM.

abstract: M.Sc.


title: Reliability, Accuracy, and Tracking Techniques of Inuit Hunters in Estimating Polar Bear Characteristics From Tracks

contributor:
Boag, Peter T.
Fekken, G. Cynthia
Biology

subject:
Traditional Knowledge
Tracking
Polar Bear
Inuit

abstract: Thesis (Master, Biology) -- Queen's University, 2010-08-15 13:06:07.948

abstract: Inuit estimates of polar bear characteristics from tracks could complement ongoing capture-mark-recapture methods to frequently monitor polar bear populations in response to climate-induced habitat changes. Before the inclusion of these Inuit track estimates, they need to be evaluated for reliability and accuracy. Building on previous work, which showed increased reliability among active Inuit hunters, this thesis research reports i) reliability in estimates of sex, age, size, and age of track of a larger number of tracks by a larger number of Inuit hunters; ii) preliminary accuracy assessments of sex and size estimates; iii) semi-structured interviews with Inuit hunters regarding their polar bear tracking experience and techniques; and iv) potential relations between Inuit hunting experience and reliability and accuracy in diagnosing tracks. The Inuit hunters were reliable and consistent as a group in making estimates of sex (α=0.74 and mean corrected item-total correlation=0.45), age (α=0.81 and mean corrected item-total correlation=0.63), and size (α=0.91 and mean corrected item-total correlation=0.73), as well as age of track estimates with the exclusion of a single participant (α=0.85 and mean corrected item-total correlation=0.63). Preliminary accuracy assessments suggest Inuit hunters are generally accurate in their estimates of sex (mean 65.28% agreement with genetic sex estimates) and potentially size from tracks, warranting further efforts to determine accuracy in these estimates as well as age and age of track. Semi-structured, open-ended interviews with each hunter revealed they use similar tracking techniques, which may explain their high agreement in making estimates. In addition, Inuit tracking experience and the use of particular tracking methods may correlate with individual reliability and accuracy in track diagnoses. These results suggest the information that Inuit hunters provide may inform any tracking-based polar bear survey.

abstract: M.Sc.


title: Computational Study of Wolff's Law Utilizing Design Space Topology Optimization: A New Method for Hip Prosthesis Design

contributor:
Kim, Il-Yong
Mechanical and Materials Engineering

subject:
topology optimization
bone remodeling
wolff's law
hip prosthesis design
design space optimization
micro-level finite element analysis

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-08-16 15:30:55.144

abstract:
The law of bone remodeling, commonly referred to as Wolff's Law, asserts that the internal trabecular bone adapts to external loadings, reorienting with the principal stress trajectories to maximize mechanical efficiency, thereby creating a naturally optimum structure. The primary objective of the research was to utilize an advanced structural optimization algorithm, called design space optimization (DSO), to create a numerical framework to perform a micro-level three-dimensional finite element bone remodeling simulation on the human proximal femur and analyze the results to determine the validity of Wolff's hypothesis. DSO optimizes the layout of material by iteratively distributing it into the areas of highest loading, while simultaneously changing the design domain to increase computational efficiency. The result is a "fully stressed" structure with minimized compliance and increased stiffness. The large-scale computational simulation utilized a 175µm mesh resolution and the routine daily loading activities of walking and stair climbing. The resulting anisotropic human trabecular architecture was compared to both Wolff's trajectory hypothesis and natural femur data from the literature using a variety of visualization techniques, including radiography and computed tomography (CT). The remodeling predictions qualitatively revealed several anisotropic trabecular regions comparable to the natural human femurs. Quantitatively, the various regional bone volume fractions from the computational results were consistent with CT analyses. The strain energy proceeded to become more uniform during optimization; implying increased mechanical efficiency was achieved. The realistic simulated trabecular geometry suggests that the DSO method can accurately predict three-dimensional bone adaptation due to mechanical loading and that the proximal femur is an optimum structure as Wolff hypothesized.

The secondary objective was to revise this computational framework to perform the first in-silico hip replacement considering micro-level bone remodeling. Two different commercially available hip prostheses were quantitatively analyzed using stress, strain energy, and bone mineral density as performance criteria and qualitatively visualized using the techniques above. Several important factors for stable fixation, determined from clinical evaluations, were evident: high levels of proximal bone loss, distal bone growth, and medial densification. The results suggest the DSO method can be utilized for comparative prosthetic implant stem design, uniquely considering post-operation bone remodeling as a design criterion.

abstract: M.A.Sc.