title: Fuelling a War Machine: Canadian Foreign Policy in the Sino-Japanese War, 1937-1945

contributor:
Hill, Emily M.
History

subject:
Canada
China
Sino-Canadian
Second World War
World War Two
World War 2
Japan
Mackenzie King
Chiang Kai-shek
Song Meiling

abstract: Thesis (Master, History) -- Queen's University, 2011-05-05 15:23:06.094

abstract:
The subject of Canada’s policy-making in relation to the Sino-Japanese War (1937-1945) has been neglected for over half a century. Therefore neither the scope of Canada’s official assistance to the Chinese during their War of Resistance against Japan nor the motivations behind this assistance have been fully explained or adequately contextualized. Through research using archival records and other primary and secondary sources, the thesis sheds light on the ways in which Canadians chose to respond to Chinese efforts to secure an ally against Japan. Revealing unscrupulous opportunism on the Canadian side during China’s struggle against Japan, the thesis contributes to a revisionist trend which takes aim at romantic mythology about Canadians’ virtuous role in the Second World War.
From 1931 to 1941, the Government of Canada sought to maintain a neutral position regarding Japanese encroachments in China. This was partly to honour a friendship established in the First World War but also to protect Canadian exporters’ valuable sales of strategic minerals to Japan. After the attack on Pearl Harbor, pro-Japanese sympathy among Canadians eroded and trade with Japan became politically untenable. In 1942, already five years after the beginning of full-scale war between Japan and China, the Canadian government began preparations to provide material assistance to the beleaguered Chinese. Increasing dialogue between Mackenzie King and Chiang Kai-shek, especially communications through Chiang’s wife Song Meiling, nurtured a promising friendship despite King’s unwillingness to commit “the lives of white men” to war in China and apparently ensured that several shipments of arms and munitions were provided to Chiang’s armies. As the research reveals, the assistance was motivated by hopes of cultivating “goodwill” in China that would favour Canadian businesses after the war. However, the official decision to assist China against Japan sparked a new controversy. Doubts about China’s postwar political stability gave rise to questions about the danger that Canadian munitions would be used in an imminent Chinese civil war. Such warnings, as it turned out, were merited. A bloody conflict between the Communists and Nationalists would erupt in China shortly after the end of the Second World War, in part waged with Canadian weapons.

abstract: M.A.


title: Quantitative Interference and Capacity Analysis of Broadband Multi-Hop Relaying Networks

contributor:
Hassanein, Hossam S.
Ahmed, Sulyman Iyanda
Electrical and Computer Engineering

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:
mobile multi-hop relaying
OFDM systems
amplify-and-forward relaying
broadband wireless access

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2011-05-05 15:15:39.576

abstract: This thesis analyzes the Bit Error Rate (BER) performance of Orthogonal Frequency Division Multiplexing (OFDM) systems in mobile multi-hop relaying channels. We consider the uplink scenario and quantify the effects of mobile channel impairments such as Doppler Shift due to user mobility per hop, high-power amplifier distortions when amplifying the transmitted/relayed OFDM symbol per hop, as well as the cumulative effects of these impairments over multi-hop relaying channels. It is shown that the resulting inter-carrier interference (ICI) due to the cumulative effects of the phase noise generated by these impairments per hop becomes very significant in a multi-hop relaying communication system, and severely degrades the BER performance of the system. Simulation results agree well with, and validate the analysis.

abstract: PhD


title: Comparative Performance Study of LTE Uplink Schedulers

contributor:
Hassanein, Hossam S.
Ali, Najah Abu
Electrical and Computer Engineering

subject:
3GPP
LTE
Uplink Scheduling
Resource Allocation
Performance Evaluation

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2011-05-07 12:43:54.983

abstract:
Long Term Evolution (LTE) constitutes a significant milestone in the evolution of 3G systems towards fourth generation (4G) technologies. The performance targets promised by LTE makes it an ideal solution to accommodate the ever increasing demand for wireless broadband. LTE's promised performance targets were made possible due to improvements such as a simplified system access architecture and a fully IP-based platform. LTE has also great enhancements in its enabling radio technologies by introducing Orthogonal Frequency Division Multiplexing (OFDM) and advanced antenna technologies. In addition, LTE capabilities are further improved with enhanced Quality of Service (QoS) support for multiple data services, such as voice and other multimedia applications.

LTE packet scheduling plays an essential role as part of LTE's Radio Resource Management (RRM) to enhance the system's data rate and to support the diverse QoS requirements of mobile services. LTE packet scheduler should intelligently allocate radio resources to mobile User Equipments (UEs) such that the LTE network adheres to its performance requirements. In our work, we perform a performance evaluation of multiple LTE scheduling algorithms proposed for LTE uplink transmission. The evaluation takes place in single and mixed traffic scenarios to exploit the strengths and weaknesses of proposed algorithms. Simulation results illustrated the importance of a scheduler's awareness of uplink channel conditions and QoS requirements in the presence of single and multiple traffic scenarios. Accordingly, we provide recommendations for future scheduling algorithm proposals, and ways to enhance the existing schedulers.

abstract: M.A.Sc.


title: Coinfection and the Evolution of Resistance: A Mathematical Analysis

contributor:
Day, Troy
Mathematics and Statistics

subject:
Coinfection
Mathematical Biology

abstract: Thesis (Master, Mathematics & Statistics) -- Queen's University, 2011-05-05 16:36:40.865

abstract:
This thesis investigates the effect of coinfection on the emergence of resistant pathogens.
Firstly, a multiple infection model with treatment is derived and the conditions for invasion are established.
 The invasion condition is then related to an equivalent and easier to obtain condition, R0,
 by applying  the Next-Generation Theorem. Due to its biological interpretation,
  a heuristic derivation of R0 as the invasion condition is also given.
 Then assuming that resistance comes at a cost to the pathogen, and using a very simple within-host model, we establish under which specific
set of biological assumptions we should expect coinfection to increase or decrease R0.
Specifically, we obtain that in the no cost of resistance case, reduced transmission case, and increased
mortality case, that coinfection  will increase the R0 value and that in the reduced growth
and poor competitor case that the effect is indeterminate. We also introduced a method for
approximating the intrinsic growth rate when the coinfection efficiency is assumed to be small.
Using this method, we show that we obtain the same trend for the cost of resistance cases
when comparing our estimate for the intrinsic growth rate for the coinfection case versus
the intrinsic growth rate for the single infection case. We also use this approximation to
estimate the percentage of resistance as a function of time. Finally, we analyze how both
the intrinsic growth rate and R0 respond to a changing treatment rate, compared
to the intrinsic growth rate and R0 value in the single infection case. We found that
the change in R0 and the intrinsic growth rate can be greater or smaller than the change
in R0 or the intrinsic growth rate for the single infection case.

abstract: M.Sc.


title: Design and Manufacture of a High-Frequency Annular Array Ultrasound System for Medical Imaging

subject:
Engineering Physics
Medical Ultrasound

abstract: Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-05-06 13:15:34.495

abstract: This thesis presents the design of a high-frequency annular array ultrasound system suitable for medical imaging. To reduce the cost of the system, off-the-shelf parts were used whenever possible. The system consists of four main components; 1) a transmit beamformer, 2) a high voltage pulse generator, 3) an annular array transducer and 4) a receive beamformer. The transmit beamformer and pulser were designed for an 8-channel array but could be easily expanded for larger arrays. The pulser produces monocycle electrical pulses with centre frequencies that could be adjusted from 10-50 MHz and with amplitudes up to 90 Vpp. The annular array transducer has 12 equal area elements and a total active aperture of 6 mm. The transducer array produced pulses with a centre frequency of 20 MHz and 50% bandwidth. The resulting images had a lateral resolution of 172.5 μm at 10 mm and an axial resolution of 180 μm. A new fabrication method was developed that makes it easier to build the array. The receive beamformer was based on a commercial 8-channel analog-to-digital converter. The digital signals were transferred to a laptop where the beamforming was performed in software. This avoided the need to develop custom hardware and allowed it to be reconfigured for different transducers by simply modifying the software. The beamformer used a new interpolation method that reduced the required sampling frequency while maintaining a satisfactory radiation pattern. The system produces images at 10 frames/sec.

abstract: PhD


title: Development of New Fluorous Stationary Phase Technologies for Improved Analytical Separations

contributor:
Oleschuk, Richard
Chemistry

subject:
Analytical Chemistry
Separation Science
Chromatography
Fluorous Chemistry

abstract: Thesis (Ph.D, Chemistry) -- Queen's University, 2011-05-06 17:03:14.803

abstract:
Applications taking advantage of fluorine-fluorine interactions for separations are a recent analytical trend, with benefits in terms of cost, ease of use and specificity cited as advantages of these so-called “fluorous” techniques.  While most current fluorous separations employ columns packed with microspheres, columns based on entrapped microspheres, porous polymer monoliths (PPMs) and open tubes all represent viable alternatives to conventional packed capillaries.  In this thesis, the design, optimization and implementation of fluorous stationary phases based on all three of these new technologies are explored.  Development of methods and techniques using these systems are presented, with factors affecting their performance being examined.  Doing this, the specificity of the fluorous interaction can also be explored, and potential applications for these new materials can be discussed.
                                          For the work with entrapped microspheres, the columns that were formed did not prove to have an advantage over those that were unentrapped.  Although affixing spheres within a matrix is known to have benefits in terms of bed stability over repeated use, the inclusion of a polymer coating proved to represent a greater concern for the availability of the bead-based stationary phases.  Layers of polymer forming over the surface were shown to limit the access of analytes to the entrapped microspheres, restricting the usefulness of these materials.
                                          The work with fluorous monoliths proved the most successful, providing clear evidence of improved selectivity when compared to analogs made without fluorination.  Fluorous retention specificity was also effectively examined, with secondary effects probed and compared to those that had been discussed for commercially-available fluorous microspheres.  Results showed that the monoliths were very much in-line with what had already been seen for sphere-based systems, with residual substrate character providing only a slight contribution to the observed separations.
                                      Finally, development of open-tubular columns based on microstructured optical fibers was the most speculative of the projects discussed here.  The introduction of a fluorous stationary phase through silanization was demonstrated to be an effective method for imparting chromatographic selectivity into these columns, and controllable factors such as treatment protocol and silane character were shown to affect the performance of the resulting materials.

abstract: PhD


title: Toxicity of Chemically Dispersed Crude Oil to Herring Embryos

contributor:
Hodson, Peter
Biology

subject:
Oil
Chemical Dispersion
Toxicity
Herring

abstract: Thesis (Master, Biology) -- Queen's University, 2011-05-06 16:59:51.507

abstract: The use of chemicals to disperse oil spills raises concerns for organisms living below the surface of the water.  While decreasing the surface area of the slick, chemical dispersants increase the amount of oil in the water column, the surface-to-volume ratio of droplets, the partitioning to water of the toxic constituents of oil, and the bioavailability of oil to pelagic and benthic organisms.  Chemical dispersion can increase the exposure to polycyclic aromatic hydrocarbons (PAH) by 100-fold.  As a model for a full-scale spill at sea, a wave tank was used to simulate chemical and natural dispersion of spilled oil to determine if the concentrations of chemically dispersed oil were sufficient to cause toxicity to embryos of Atlantic herring (Clupea harengus).  While the hydrocarbon concentrations of dispersed oil from the wave tank were not large, the exposure response relationship was consistent with that of laboratory-prepared dispersed oil.  Additionally, the toxicities of chemically dispersed oil prepared in the lab to Pacific (Clupea pallasi) and Atlantic herring were compared to ensure that the wealth of literature available on Pacific herring could be used for assessing the risk of oil exposure to Atlantic herring.  Exposures to low concentrations of dispersed oil for short periods (2.4 to 24 h) consistently increased the incidence of blue sac disease, and decreased the percentage of normal embryos at hatch, indicating that even brief exposures to oil could be detrimental to the survival and recruitment of herring.

abstract: M.Sc.


title: Electrical and Optical Probing of Extremely Large Planar Polymer Light-Emitting Electrochemical Cells

subject: LEC Polymer

abstract: Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-05-12 16:27:05.208

abstract:
Polymer light-emitting electrochemical cells (LECs) are unique solid-state light-emitting devices operating on the principle of in situ electrochemical doping and the formation of a p-n junction. Compared to conventional polymer light-emitting diodes, LECs possess some favorable device characteristics, making them attractive candidates for flat panel display applications. However, the underlying operating mechanism of LECs has been the subject of intense scrutiny and debate. The extremely large planar devices demonstrated by Dr. Gao’s group offer an unparalleled spatial resolution for investigating the electrochemical doping process. With time-lapse fluorescence imaging, our group has demonstrated the existence of the electrochemical doping and the p-n junction in an operating LEC. However, the LEC electronic structure has never been adequately studied and understood. In this thesis, the original research on the electrical and optical scanning measurements on extremely large planar LECs is described.
A fresh LEC film has, for the first time, been turned on to form a light-emitting p-n junction by biasing a pair of probes that form direct contacts with the LEC film. The quasi-one-dimensional probe tips allow insight into the electrochemical doping mechanism, without being disturbed by imperfections in the pre-deposited electrodes. Time-lapse fluorescence imaging has exhibited p- and n-doping of various shapes and shades, p-n junction electroluminescence, and the effects of bias reversal. The observed doping reaction kinetics suggests that n-doping is reaction-limited whereas p-doping is diffusion-limited. Furthermore, the electric potential and conductivity distributions of extremely large planar LECs have been mapped. The results show that the p-doping is more conductive than n-doping. More importantly, The results provide the first evidence that the p-n junction is indeed a graded one with decreasing conductivity and doping concentration from the electrode contact to the metallurgical junction. In addition, the optical beam induced current (OBIC) measurement has been explored to map the built-in electric field of extremely large planar LECs. This result clearly shows that a large electric field exists only around the junction region rather than in the electrode region. Moreover, the result confirms that the LEC electronic structure is a graded p-n junction.

abstract: PhD


title: Characterization of the MexT Regulator of the mexEF-oprN Multidrug Efflux Operon of Pseudomonas aeruginosa

contributor:
Poole, R. Keith
Microbiology and Immunology

subject:
mexEF-oprN, efflux,  aeruginosa
nitrosative stress
MexT

abstract: Thesis (Ph.D, Microbiology & Immunology) -- Queen's University, 2011-05-15 20:59:57.018

abstract: Pseudomonas aeruginosa is resistant to many clinically-relevant antibiotics and this is partly attributable to multidrug efflux systems in this organism.  One of these, MexEF-OprN, exports chloramphenicol, fluoroquinolones and trimethoprim and is positively regulated by MexT, encoded by the mexT gene that is located upstream of the efflux genes.  MexT also positively regulates the mexS gene that encodes an oxidoreductase of unknown function and whose loss increases expression of mexEF-oprN.  A null mutation in the mexS gene of P. aeruginosa increased expression of two 3-gene operons, PA4354-PA4355-PA4356 and PA2813-2812-2811.  This increased expression, which paralleled an increase in mexEF-oprN expression in the same mutant, was, like mexEF-oprN, MexT-dependent.  The PA4356 (xenB) gene product is homologous to a xenobiotic reductase in P. fluorescens shown to remove nitro groups from trinitrotoluene and nitroglycerin. As nitration is a well-known result of nitrosative stress, a role for xenB (and the co-regulated mexEF-oprN and PA2813-2812-2811) in a nitrosative stress response was hypothesized and tested.  Using S-nitrosoglutathione (GSNO) as a source of nitrosative stress, expression of mexEF-oprN, xenB and PA2811 was shown to be GSNO-inducible, though in the case of xenB and PA2811 this was only seen in a mutant lacking MexEF-OprN and only for xenB, this GSNO-inducible expression was dependent upon MexT.  Consistent with MexT being required for mexEF-oprN and PA4354-PA4355-PA4356 expression, MexT bound to their promoter regions. Chloramphenicol, a nitroaromatic antimicrobial that is a substrate for MexEF-OprN and resembles a nitrosated nitrosative stress product accommodated by this efflux system induced expression of mexEF-oprN, but not xenB, or PA2811, and this was dependent upon the MexT regulator. In addition to MexT positive-regulating activity of genes in response to nitrosative stress, MexT also negatively regulates the expression of mexAB-oprM through direct binding to its promoter region and the oprD gene, encoding an outer membrane porin that provides a portal of entry for basic amino acids and carbapenem, whose expression was reduced only by GSNO.

abstract: PhD


title: Physical activity, sedentary behaviour and sleep: associations with cardiometabolic risk in abdominally obese men and women

contributor:
Ross, Robert
Kinesiology and Health Studies

subject:
Physical activity
Sedentary behaviour

abstract: Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2011-05-17 13:33:52.518

abstract:
Current guidelines suggest that physical activity must be performed at a moderate-to-vigorous intensity (MVPA) and accumulated in bouts of at least 10 consecutive minutes to elicit improvement in cardiorespiratory fitness (CRF). In the first study we sought to determine whether the duration and intensity of objectively measured incidental physical activity (IPA; activity performed below the designated threshold) was associated with CRF in abdominally obese, inactive men (n=43) and women (n=92). Secondary analyses examined the associations between light physical activity (LPA), sporadic moderate physical activity (MPA; accumulated in <10 minute bouts), and CRF. Both duration and intensity of IPA were positively associated with CRF among inactive, abdominally obese adults. Sporadic MPA, but not LPA, was an independent predictor of CRF.
Whereas some observations suggest that sedentary behaviour (SED) is negatively associated with health outcomes, other evidence fails to support this notion. The primary aim of the second study was to clarify the relationships between SED, LPA, and MVPA with 2-hour glucose and insulin resistance in inactive adults (43 men, 92 women) with abdominal obesity. Secondary analyses examined the association between SED, LPA, MVPA and other common cardiometabolic risk factors.  Neither SED nor the physical activity variables were associated with 2-hour glucose or insulin resistance. SED was not associated with any cardiometabolic risk factor; with the exception of blood pressure, LPA was not associated with any cardiometabolic risk factor; and MVPA was independently associated with total cholesterol and triglycerides.
Whether IPA is associated with abdominal obesity is unknown. The purpose of study three was to determine the association between IPA and abdominal adipose tissue depots (visceral adipose tissue and subcutaneous adipose tissue) in inactive men (n=42) and women (n=84). Secondary analyses examined the associations between SED, sleep duration, and caloric intake with abdominal obesity. IPA was not associated with any measure of abdominal obesity, nor was LPA.  After control for age and sex, MPA was negatively associated with visceral adipose tissue. SED and sleep duration were not associated with abdominal obesity. Caloric intake was not associated with abdominal obesity after control for age and sex.

abstract: PhD


title: Characterization and Processing of Lignocellulosic Biomass in Ionic Liquids

contributor:
Cunningham, Michael F.
Champagne, Pascale
Chemical Engineering

subject:
Ionic Liquids
Lignocellulose
Cellulose
Lignin
Biomass
Biotechnology
Value-Added Products
Biorefinery
IR Spectroscopy
PLS Regression
Optical Microscopy
Rapid Screening
Biomass Dissolution
Carbon Dioxide

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2011-05-25 22:58:17.744

abstract:
In the last decade there has been increasing research interest in the value of bio-sourced materials from lignocellulosic biomass. The dissolution of cellulose by ionic liquids (ILs) has led to investigations including the dissolution of cellulose, lignin, and complete biomass samples and the in situ processing of cellulose. Rapid quantitative measurement of cellulose dissolution in ILs is difficult. In this work, Fourier transform infrared spectroscopy (FTIR) spectra of cellulose dissolved in 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) were subjected to partial least squares (PLS) regression to model dissolved cellulose content. PLS regression was used due to the ease in developing predictive models with this technique in addition to linear regression being ineffectual for modeling when applied to potentially thousands of variables. Applying a normalization data treatment, before regression, generated a model that estimated cellulose content within 0.533 wt%. The methods described provided the basis for a rapid methodology to determine dissolved cellulose content.
Development of rapid and facile screening techniques to determine the effectiveness of various ILs as solvents for cellulose or lignin will aid in the development of lignocellulosic based bioproducts. In this work, optical microscopy with and without the use of cross-polarized lenses, was used to monitor cellulose and lignin dissolution in two imidazolium-based and two phosphonium-based ILs as well as n,n-dimethylacetamide/lithium chloride (DMAc/LiCl), demonstrating that this technique could be applied more broadly than solely for ILs. The described optical microscopy methodology was more rapid and sensitive than more traditional techniques, such as visual inspection.
The viscosity of [emim][OAc] (162 cP) is 100 times that of water at 20°C and could inhibit its use as a solvent for cellulose. There is a need for simple, low-cost and environmentally benign methods to reduce the viscosity of ILs to aid in cellulose dissolution. In this work, 4 wt% cellulose dissolved in [emim][OAc] was subjected to 50 psi CO2 and 20 psi N2, as a control environment, at both 50°C and 75°C. After 24 hours a nearly 2-fold increase in dissolved cellulose over the N2 control was demonstrated through the application of a 50 psi CO2 environment for cellulose dissolution in [emim][OAc] at 50°C.

abstract: M.A.Sc.


title: Experimental and Computational Analysis of Evaporative Spray Cooling for Gas Turbine Exhaust Ejectors

contributor:
Birk, Michael A.
Mechanical and Materials Engineering

subject: Evaporative Spray Ejector Air-Air Naval Cooling Droplet Computational CFD Analysis

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2011-05-18 14:47:50.52

abstract:
This research studied the effects of evaporative spray cooling on air-air ejector performance. Experimental data was collected for the purpose of validating computational simulations.  This was done by modifying an existing air-air ejector to accommodate four spray flow nozzles which were used to atomize cooling water. The only parameter that was varied throughout the study was the mass flow rate of cooling water. One single phase (air) case and four spray flow cases where performed and analyzed. The purpose of the single phase experiment was to have a baseline for the air-air ejector performance and isolate the sources of experimental error contributed by spray flow. Three specialized multiphase flow instruments were designed and fabricated by the author to measure, gas phase temperatures, spray mass flow rates, and mixture total pressures.
A computational study was performed using the collected experimental data for inlet continuous phase and spray mass flow as boundary conditions for equivalent simulations. A temperature gradient modified turbulence model was written by the author to better predict the mixing rates found experimentally which was used for the duration of this research. Secondary droplet breakup was modeled by the author using empirical correlations following preliminary simulations recognizing the deficiencies of commercially available breakup models.
Comparison of experimental and computational cases produced mixed results. It was found that the experimental gas temperature instrument performed poorly for the local droplet fluxes encountered during testing. The spray sampling probe showed more promising results with two integrated mass flows agreeing within 6% of computational simulations. The total pressure probe solved the issue of pressure port clogging, but measurements were representative of mixture density which made an inferred velocity calculation difficult. It was found that evaporation of spray flow before the nozzle exit plane caused a reduction in dynamic pressure and a reduction in back pressure.
A full scale simulation was performed to determine the effects of scaling on evaporative spray cooling performance. It was found that for the geometrically similar full scale model, the total droplet surface area and particle residence times scaled up with the model which increased cooling performance.

abstract: M.A.Sc.


title: Considerations on the use of Impedance Spectroscopy for the Detection of Virions Trapped in Quadrupolar Microelectrode Arrays

contributor:
Docoslis, Aristides
Chemical Engineering

subject: Impedance Biosensors Microfluidic

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2011-05-20 02:35:15.678

abstract:
The impedance response of a quadrupolar microelectrode array was studied over a wide frequency range to determine whether particles captured at the center of the array could be detected impedimetrically. The microelectrode array (denoted as DEP chip) uses dielectrophoretic forces to concentrate particles at its center. Initial results showed that there was a large electrode-silicon-electrode (ESE) capacitance which dominated at high frequencies. This capacitance was reduced by decreasing the electrode area and increasing the insulating layer thickness. These measures however proved fruitless as this capacitance was still significantly greater then the dielectric capacitance of the chip. This ESE capacitance can be eliminated through the use of a glass substrate so that the dielectric response of the chip dominates at higher frequencies. Since the ESE capacitance prevented experimental validation of impedance spectroscopy as a signal transduction method, computer simulations were performed. These simulations indicated that capture with the current DEP chips would not have a significant impact on the impedance of the chip. Decreasing the electrode gap distance and reducing the area of the electrodes, which is recommended for future work, can remedy this.
As measureable changes in the dielectric capacitance of the chip are not possible, a reaction scheme was developed to translate the capture of viral particles into a change in medium conductivity. An ELISA type system was proposed where the viral particles would be functionalized with urease. This uease would then be used to degrade non-ionic urea into ionic products thereby increasing the medium conductivity. A model was formulated to predict the conductivity increase expected for low concentrations, and validated using higher concentrations of biotinylated-urease. Urease from commercial sources proved not to be a viable option as it does not possess a high enough activity to produce a significant conductivity change given the low concentrations of viral particles expected after collection. Urease with suitable activity is produced by the organism Ureaplasma urealyticum which has an activity of 180 000 µmol urea catalyzed min-1 mg urease-1. It is not recommended that this method be pursued further due to technical challenges that would be encountered.

abstract: M.A.Sc.


title: A Comparison of Neighbourhood Designs for Detachment Jericho

subject:
LEED-ND
Sustainable Design
Jericho Lands
Vancouver
Subdivision Design
Neighbourhood Planning


title: A Virtual Joystick as a Novel Interaction Modality for Surgeon-Computer Interaction During Computer-Assisted Surgical Procedures

contributor:
Stewart, James
Computing

subject: surgeon computer interaction joystick

abstract: Thesis (Master, Computing) -- Queen's University, 2011-05-24 12:27:57.998

abstract: Interacting with a computer system in the operating room (OR) can be a frustrating experience for a surgeon, who currently has to verbally delegate to an assistant every computer interaction task. This indirect mode of interaction is time consuming, error prone and can lead to poor usability of OR computer systems. This thesis describes the design and evaluation of a joystick-like device that allows direct surgeon control of the computer in the OR. The device was tested extensively in comparison to a mouse and delegated dictation with seven surgeons, eleven residents, and five graduate students. The device contains no electronic parts, is easy to use, is unobtrusive, has no physical connection to the computer and makes use of an existing tool in the OR. We performed a user study to determine its effectiveness in allowing a user to perform all the tasks they would be expected to perform on an OR computer system during a computer-assisted surgery. Dictation was found to be superior to the joystick in qualitative measures, but the joystick was preferred over dictation in user satisfaction responses. The mouse outperformed both joystick and dictation, but it is not a readily accepted modality in the OR.

abstract: M.Sc.


title: Home Care Utilization Patterns Among the Elderly Population: a Case Study of Ontario, Canada

contributor:
Rosenberg, Mark W.
Geography

subject:
Home Care
Ontario
Aging

abstract: Thesis (Master, Geography) -- Queen's University, 2011-05-21 00:10:26.287

abstract:
The demand for home care increased dramatically in Canada in the past decade. This was because more patients were discharged from hospital, more emphasis was put on health care at the home and community levels, the continuing aging of the population, advancements in technology, and the adoption of a more cost-effective strategies. Though home care is still not a part of Canadian Health Act (CHA) and there are no national regulations for home care, people value the significance of home care. Home care is now one of the fastest growing sectors in Canada’s health care system. With a focus on the elderly population in the province of Ontario, this thesis uses data from the Canadian Community Health Survey (CCHS cycle 1.1, 2.1 and 3.1) to examine utilization patterns of home care considering social and geographical factors, the variation within home care service provision, and unmet home care need. The major findings of the thesis are that seniors with poorer health status, older age, female, with lower household incomes, marital status widowed/separated/divorced/single/never married, and living in urban areas are more likely to use home care. At the same time, seniors who are older, with poorer health status, and suffering from chronic condition are in a more vulnerable position to receive the home care they need. A large amount of responsibility was shifted to informal caregivers due to the budget constraints and the policy bias of the government. Access to home care is unequal on a geographical scale. Seniors living in rural and remote areas tend to have more unmet home care
needs than seniors living in urban areas. People living in rural northern regions in Ontario have the least access to home care. Also, seniors living in urban areas have a greater chance of getting government provided care than those living in rural areas. Overall, under the current managed competition model of home care in Ontario, unequal accessibility, insufficient services, an excessive burden on informal caregivers are observed.

abstract: M.A.


title: Statistical Inference for the Treatment Effect in Cancer Clinical Trials

contributor:
Tu, Dongsheng
Mathematics and Statistics

subject:
Treatment effect
Clinical trials

abstract: Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2011-05-21 11:07:52.992

abstract:
Randomized clinical trials provide the best evidence on the effect of treatment studied. There are different types of measures on the
treatment effect, depending on the endpoints of the trials. For a given measure, based on the data from clinical trials, various statistical procedures are available for the inference of the treatment effect in terms of this measure.

In a cancer clinical trial with a time to an event as the endpoint, hazard ratio is a popular measure for the relative difference
between treatment groups. Most current statistical inference procedures for hazard ratio rely on the proportional hazard
assumption, which may not be applicable to practice when it does not hold. Nonparametric confidence intervals for the hazard ratio have been proposed based on the asymptotic normality of the kernel estimate for the hazard ratio, but they were found not very satisfactory in the simulation studies. In the first part of this thesis, the empirical likelihood method is used to construct the confidence interval for the time-dependent hazard ratio. The asymptotic distribution of the empirical likelihood ratio is derived and simulation studies are conducted to evaluate the proposed method.

It was also argued that the measure of the relative treatment effect based on the hazard ratio may be difficult to understand by clinicians. An alternative measure called probabilistic index was suggested and the C-index was proposed to estimate this index. However, it was pointed out recently that the expected value of the estimate based on the C-index may be far removed from the true
index. In the second part of this thesis, assuming a semi-parametric density ratio model, two new estimates based on respectively the conditional likelihood and weighted empirical likelihood are proposed. Associated confidence intervals are also derived based on the bootstrap re-sampling method. The proposed inference procedures are evaluated by Monte-Carlo simulations and applied to the analysis of data from a clinical trial on early breast cancer.

After primary analysis including all patients is completed in clinical trials, analysis by subgroups defined based on covariates of patients is often of interest to assess the homogeneity of treatment effects over these subgroups. The treatment-covariate interaction is usually used for this assessment. In the last part of this thesis, a non-parametric measure is used to quantify the interaction between treatments and binary covariates in the presence of censoring. Asymptotic distribution of the interaction estimates are derived and the bootstrap method is applied to construct the
confidence intervals. The proposed approaches are also evaluated and compared by Monte-Carlo simulations and applied to a real data set from clinical trial.

abstract: PhD


title: Modernist Ecology: Modernism and the Reimagination of Nature

contributor:
Willmott, Glenn
Wallace, Molly
English

subject: modernism; ecocriticism; twentieth century literature; aesthetics

abstract: Thesis (Ph.D, English) -- Queen's University, 2011-05-23 20:44:46.812

abstract: Countering the trend in contemporary ecocriticism to advance realism as an environmentally responsible mode of representation, this essay argues that the anti-realist aesthetics of literary modernism were implicitly “ecological.” In order to make this argument I distinguish between contemporary and modernist ecological culture (both of which I differentiate in turn from ecological science); while the former is concerned primarily with the practical reform characteristic of what we now call “environmentalism,” the latter demanded an all-encompassing reimagination of the relationship between humanity and nature. “Modernist ecology,” as I call it, attempted to envision this change, which would be ontological or metaphysical rather than simply social, through thematically and formally experimental works of art. Its radical vision, suggestive in some ways of today’s “deep” ecology, repudiated modern accounts of nature as a congeries of inert objects to be manipulated by a sovereign subject, and instead foregrounded the chiasmic intertexture of the subject/object relationship. In aesthetic modernism we encounter not “objective” nature, but “nature-being” – a blank substratum beneath the solid contours of what philosopher Kate Soper calls “lay nature” – the revelation of which shatters historical constructions of nature and alone allows for radical alternatives. This essay looks specifically at modernist ecology as it appears in the works of W. B. Yeats, D. H. Lawrence, and Samuel Beckett, detailing their attempts to envision revolutionary new ecologies, but also their struggles with the limited capacity of esoteric modernist art to effect significant ecological change on a collective level.

abstract: PhD


title: The Role of Oxidative Stress and Epigenetic Modifications in Valproic Acid-Induced Teratogenesis in the Mouse

contributor:
Winn, Louise M.
Pharmacology and Toxicology

subject:
Valproic Acid
Epigenetics
Oxidative Stress
Teratogenesis
Cell Cycle Arrest
Apoptosis

abstract: Thesis (Ph.D, Pharmacology & Toxicology) -- Queen's University, 2011-05-24 13:12:33.778

abstract: Exposure to the anticonvulsant valproic acid (VPA) is associated with a 7.5% rate of major malformations and a 1-2% incidence of neural tube defects (NTDs).  Although the teratogenic outcomes resulting from VPA use during pregnancy were first identified in the 1980s, the mechanisms by which VPA induces birth defects are not fully elucidated.  Based on evidence in the literature, the studies in this thesis examined the role of in utero VPA exposure on oxidative stress and epigenetic alterations in the developing embryo to provide further mechanistic insight into VPA’s teratogenic pathway.  The first study investigated the role of oxidative stress in VPA-induced teratogenesis.  Using CD-1 mice, catalase was shown to protect against VPA-induced effects on developmental and morphological parameters in both whole embryo culture and in vivo models.  Studies in whole embryo culture demonstrated that markers of oxidative damage were not altered by VPA; however, VPA increased apoptosis in the neuroepithelium, which was attenuated by the addition of catalase.  The second objective addressed epigenetic modifications induced by VPA in an in vivo mouse model.  Maternal administration of VPA resulted in increased acetylation of histones H3 and H4, increased methylation of histone H3K4, and decreased methylation of histone H3K9.  Furthermore, these changes were localized to VPA target tissues including the neuroepithelium, heart, and somites.  Global DNA methylation in the embryo was not altered by VPA.  The final objective was to determine VPA’s effect on a marker of DNA damage, markers of cell cycle proteins, and a marker of apotosis in vivo.  Maternal administration of VPA resulted in a rapid increase of γH2A.X, a marker of DNA double strand breaks (DSBs).  Increased expression of p27KIP1, a cyclin-dependent kinase inhibitor, and activated caspase-3, a marker of apoptosis, were observed and these changes were localized to the neuroepithelium of developing embryos.  In conclusion, this thesis supports the hypothesis that VPA-induced increases in ROS production and HDAC inhibition may lead to altered gene expression patterns and consequently teratogenic effects, namely NTDs.

abstract: Not all papers have been published yet.

abstract: PhD


title: Feature Extraction Workflows for Urban Mobile-Terrestrial LiDAR Data

contributor:
Treitz, Paul
Harrap, Robin
Geography

subject:
lidar
GIS
Mobile Mapping
Remote Sensing
Ontology
Geovisualization
Human-Computer Interaction
Kinematic LiDAR
Feature Extraction
Image Processing
GEOBIA
Object-Oriented

abstract: Thesis (Master, Geography) -- Queen's University, 2011-05-24 13:10:15.198

abstract:
Mobile Terrestrial LiDAR (MTL) is an active remote sensing technology that uses laser-based ranging and global positioning systems (GPS) to record 3D point location measurements on surfaces within and near transportation corridors, such as along a railroad track or a street. This thesis examines geovisualization for improving user-oriented workflows and also examines geographic object-based image analysis (GEOBIA) for the development of automated feature extraction.  A LiDAR sensor-centric perspective during the data acquisition phase is used to organize data for the user and to transform the data into a 2D reference frame for object-oriented image analysis of MTL data.
Organizing the display of MTL data relative to the scanner presented new opportunities for visualization techniques and was an effective method for communicating space that was scanned, or not, in an urban scene. It offers new avenues for quality assessment of MTL survey of urban environments by explicitly displaying gaps in data coverage. A number of techniques for navigating and visualizing data from a sensor-perspective are examined.
A novel sensor-perspective transformation of MTL data from three to two dimensions enables analysis of MTL data in common GIS and image-processing environments. GEOBIA software (Definiens’ eCognition) is used to construct a procedural feature extraction workflow. The procedures are constructed with semantic classes, data processing rules and functions that drive geometric segmentation and feature recognition. Geometric regularities in urban scenes and knowledge about spatial and semantic relationships are incorporated into the rule set. The results are fluidly integrated back into a GIS environment.
Investigation of alternative approaches to handling MTL data such as those carried out in this thesis are essential if this technology is to see widespread use.

abstract: M.Sc.


title: Constitutional Justice in Africa: An Examination of Constitutional Positivism, Fundamental Law and Rights in Ghana and Nigeria

contributor:
Walters, Mark D.
Law

subject: Law PhD

abstract: Thesis (Ph.D, Law) -- Queen's University, 2011-05-26 10:50:46.13

abstract: This work explores the idea of constitutional justice in Africa with a focus on constitutional interpretation in Ghana and Nigeria. The objective is to develop a theory of constitutional interpretation based upon a conception of law that allows the existing constitutions of Ghana and Nigeria to be construed by the courts as law in a manner that best serves the collective wellbeing of the people. The project involves an examination of both legal theory and substantive constitutional law. The theoretical argument will be applied to show how a proper understanding of the ideals of the rule of law and constitutionalism in Ghana and Nigeria necessitate the conclusion that socio-economic rights in those countries are constitutionally protected and judicially enforceable. The thesis argues that this conclusion follows from a general claim that constitutions should represent a ‘fundamental law’ and must be construed as an aspirational moral ideal for the common good of the people.  The argument is essentially about the inherent character of ‘legality’ or the ‘rule of law.’ It weaves together ideas developed by Lon Fuller, Ronald Dworkin, T.R.S. Allan and David Dyzenhaus, as well as the strand of common law constitutionalism associated with Sir Edward Coke, to develop a moral sense of ‘law’ that transcends the confines of positive or explicit law while remaining inherently ‘legal’ as opposed to purely moral or political. What emerges is an unwritten fundamental law of reason located between pure morality or natural law on the one hand and strict, explicit, or positive law on the other. It is argued that this fundamental law is, or should be, the basis of constitutional interpretation, especially in transitional democracies like Ghana and Nigeria, and that it grounds constitutional protection for socio-economic rights. Equipped with this theory of law, courts in developing African countries like Ghana and Nigeria will be in a better position to contribute towards developing a real sense of constitutional justice for Africa.

abstract: PhD


title: Synthesis and Applications of Nanostructured Mesoporous Organosilica Films and Monoliths

contributor:
Crudden, Cathleen M.
Chemistry

subject:
mesoporous
organosilica
films
monoliths
heavy metal sensing
structural control
capillary chromatography
surfactant-templated
sol-gel

abstract: Thesis (Ph.D, Chemistry) -- Queen's University, 2011-05-24 19:50:17.478

abstract:
Surfactant-templated, sol-gel based methodologies for the synthesis of tailored, nanostructured, hybrid inorganic–organic materials are incredibly powerful and versatile.  Although growth in this field has been explosive in recent decades, a lot of room remains to contribute to the design and synthesis of new materials, as well as the development of advanced applications.
In the work described herein, we firstly explored the synthesis of thick, mesoporous organosilica films and their application as functional coatings for solution-based, fibre-optic heavy metal sensors.  Notably, sub-ppm level detection was observed for the detection of Pb(II) in mixed aqueous–organic media in short timeframes, and progress has been made toward synthesizing organotitania films that would allow for heavy metal sensing in purely aqueous solution.  Furthermore, the utility of these types of surfactant-templated, organically-functionalized, mesostructured coatings has been preliminarily extended to other types of optical devices for heavy metal sensing.
We have also explored the use of designer amphiphilic, alkyl oligosiloxane precursors for the tightly-controlled formation of thin, self-templated, hybrid nanostructured films.  Moreover, films bearing uniaxial 2D hexagonal alignment over macroscopic length scales were obtained using polymer-treated substrates to control the interfacial interactions between the film precursors and the substrate surface.  In addition, a relatively mild UV / ozone treatment was employed to remove the alkyl moieties from the films to yield porous materials without catastrophic loss of the as-synthesized, mesostructural order.
Lastly, novel chiral, binaphthylene-based, periodic mesoporous organosilica (PMO) materials have been prepared.  With the aim of demonstrating chiral recognition with such materials, porous, co-continuous capillary monoliths have been synthesized and applied as chiral stationary phases in nano-HPLC and CEC.  Notably, enantioselective interactions between our materials and a chiral acetal-based analyte have been observed.  Quantification of these enantioselective interactions in chiral PMOs by isothermal titration microcalorimetry is also being pursued.
It has thus been demonstrated that a wide array of different functional materials may be accessed through template-based synthetic strategies.  By varying parameters such the starting monomers, the sol composition, and the interfacial interactions between reacting species and a given substrate (to name a few), the resulting materials may be tailored to meet the demands of new and emerging technologies.

abstract: PhD


title: "Oddballs and Eccentrics" ("Les Hirsutes et Les Excentriques"): Visual Arts and Artists in the Popular Press in Post-War Canada

contributor:
Jessup, Lynda
Art History

subject:
Canadian Art History
Popular Press
Post-War Canadian History
Anti-Communism in Canada
Liberalism in Canada
Cultural Policy

abstract: Thesis (Ph.D, Art History) -- Queen's University, 2011-06-02 12:18:51.194

abstract:
This dissertation examines the representation of visual arts and artists in two popular Canadian magazines.  It is based on case studies of the Montréal-based Le petit journal, a French-language magazine, and the Toronto-based English-language publication Star Weekly, from 1945 to 1968.  Both were weekly magazines with large readerships and included content for the entire family.  Neither was devoted to visual arts but both carried photographs and articles that engaged with broad issues in the field of visual arts.  As such, they represent a cross-section of ideas and perspectives that is very different from those of daily newspapers or of publications explicitly devoted to the arts.  In addition, both implicitly claimed a national perspective by including articles and information about different regions of Canada.  In this way, although in reality the two publications constitute a central Canadian perspective, inflected in each case by the particularities of their provincial locations, they claimed a national vision.
In contrast to existing research concerning art journals and art critics in Canada, my investigation involves the ownership and editorial direction of these two popular magazines.  By analyzing the content of the magazines across more than two decades, I am able to identify shifts in outlook as they occurred and consider them in the context of the period.  I have found that, although there were substantial differences between the two publications, the way that they participated in the construction of ideas was strikingly similar.  In effect, both magazines projected specific notions of the value of artists and visual arts and used this coverage to shape attitudes—to work, gender, immigration, nationalism and a host of other topics.  I argue that the presentation of ideas was rooted in both liberalism and anti-communism, and was informed by inherent self-interest on the part of the owners of the magazines.  In addition, I argue that this perspective was largely hidden within a language of disinterested public service.  Finally, I posit that representations in the popular press shaped opinions and attitudes to visual arts and artists in ways that continue to resonate today, more than forty years later.

abstract: PhD


title: Solar Photovoltaic Resource Assessment From The Macro Scale To The Meso Scale Using Airborne Laser Scanning Data And Open Source Tools

contributor:
Pearce, Joshua M.
Mechanical and Materials Engineering

subject:
GIS
shading
solar photovoltaic
global horizontal irradiance
r.sun
Light Detection And Ranging

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2011-05-26 15:35:19.118

abstract:
An understanding of the urban local potential (roof space and solar exposure) is critical for utility planning, accommodating grid capacity, deploying financing schemes and formulating future adaptive policies to take advantage of PV technology's continued price declines. This thesis provides a sequence
of methodologies to acquire and pre-process data and access solar PV potential from i) a regional scale, ii) a municipal scale and iii) a municipal district unit. This research explores and confirms the robustness and versatility of the r.sun module within the open source Geographic Resources Analysis
Support System (GRASS) for the purpose of solar irradiation modeling at different levels of surface complexity. At the regional scale, the fourteen counties in southeastern Ontario that served as a case study was found to possess over 935,000 acres appropriate for solar farm development, which could provide 90 GW of PV. At the municipal scale, another methodology was developed to provide urban
solar PV resource assessments, which is widely applicable throughout the world. The results of the case study indicate that utilities needing to plan for large scale solar electric generation in urban areas can
make a rule of thumb estimate. In the absence of advanced computational expertise and high quality remotely sensed data, 30% of the projected area of roofprints can be used as a first pass estimation of the available area for PV installation. Finally, for the municipal district unit, a separate workflow that attains a 95% accurate segmentation from raw and randomly chosen Light Detection And Ranging (LiDAR) data was demonstrated. The solar PV resource assessment on this scale returned 22,000m2 of roof area out of a two dimensional extent of approximately 40,000m2 in building coverage as suitable for the purpose of solar PV installations. With higher integration of urban texture, it was found that the global horizontal irradiation is lower than the regional scale by 30% due to near shadowing effects in downtown Kingston. The three methodologies presented here at three scales provide the foundation to enable automated analysis of solar PV potential and planning for any given region with marginal LiDAR data.

abstract: M.A.Sc.


title: Components of Biological Motion Perception

contributor:
Troje, Nikolaus F.
Psychology

subject:
psychology
cognitive psychology
vision
biological motion

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2011-05-27 09:25:30.774

abstract:
Biological motion perception, defined as the ability to retrieve information from minimal displays of animal motion, has often been discussed as though it represents a single mechanism. However, depending on the task and details of the stimuli, there have been divergent results as to whether this ability is primarily based on motion or form processing, whether it relies more on local or global information, and whether the knowledge that is applied is learned or innate. These results can be reconciled by a multi-component framework, with five major components: local motion invariant processing, structure-from-motion, figure-ground segregation, action categorization, and style recognition. Several experiments are reported that are motivated by this framework.
To investigate the sensitivity of the visual system to local motion invariants, performance was tested on a direction discrimination and a detection task with a point-light walker based on real motion-capture data or a synthetic walker created by Cutting (Chapter 2). When the walkers were displayed normally, performance was equal for both stimuli. However, when the walkers were spatially scrambled, the direction could only be determined for the natural walker, demonstrating that the invariant is found in subtle features of the local motion trajectories.
Another experiment examined the difference in attentional distribution due to the task requirements (Chapter 3). Participants looked more often at the feet in a direction task than they did in a gender task, lending support to the idea that useful information can be derived from the local motion of the feet.
Finally, Chapter 4 describes a battery of psychophysical tests that assesses each of the components of biological motion perception as independently as possible. The fact that individual performance does not correlate between tests is evidence that they measure different underlying mechanisms, supporting the multi-component framework.
In the concluding chapter, multi-component computational models of biological motion perception are evaluated within this framework, and the evidence relating the components to activity in particular brain regions is reviewed.

abstract: PhD


title: Characterization of the Baculovirus Late Expression Factor-3 Oligomerization Interaction Domains Using Protein Complementation Assay

contributor:
Carstens, Eric
Microbiology and Immunology

subject:
Baculovirus
DNA Replication
Protein Complementation Assay
Oligomerization Domains

abstract: Thesis (Master, Microbiology & Immunology) -- Queen's University, 2011-05-27 15:02:53.983

abstract: Late expression factor 3 is one of the six AcMNPV genes essential for DNA replication identified through transient replication assays. LEF-3 is a single stranded DNA binding protein responsible for the transportation of the viral helicase (P143) into the nucleus of the infected cell. In this study, a protein complementation-based assay was adapted to identify the region(s) of LEF-3 that is (are) involved in LEF-3-LEF-3 protein interactions. The full-length LEF-3, or various truncated LEF-3 regions were fused with Venus1 (N- terminus portions of full length Venus, a modified yellow fluorescence protein) or Venus2 (C- terminus). Venus1 and Venus2 fragments generated a functional fluorescent Venus protein when the two fragments were brought together by protein-protein interaction of the fused LEF-3 constructs. Fluorescence generated by coexpression of full-length LEF-3 fusion proteins confirmed that LEF-3 exists as homo-oligomer. Interaction between the full-length and the N- terminal (aa 1-189) or C- terminal regions (aa 190-385), and between the various truncated LEF-3 regions suggested the complexity of LEF-3 oligomeric structure. LEF-3 constructs deleted for NLS function revealed cytoplasmic fluorescence, suggesting that LEF-3-LEF-3 interactions occur in the absence of DNA or nuclear proteins. Because LEF-3 is essential for nuclear transporting the viral helicase (P143), the ability of LEF-3 to interact with another viral protein was investigated. P47, a sub-unit of the viral RNA polymerase was chosen because it is cytoplasmic when expressed on its own. The interaction between LEF-3 and P47 produced complete nuclear localized fluorescent signals. Overall, the results suggest that there are multiple regions of LEF-3 that are capable of closely interacting, and that multiple domains are likely involved in the oligomerization of full-length LEF-3. The interaction of LEF-3 with P47 suggests that P47 may be another LEF-3 cargo protein.

abstract: M.Sc.


title: Role of NMDA in the Visual Working Memory of the Macaque Monkey

contributor:
Paré, Martin
Neuroscience Studies

subject:
working memory
NMDA

abstract: Thesis (Master, Neuroscience Studies) -- Queen's University, 2011-05-27 14:56:41.726

abstract:
Working memory refers to the ability to retain information for short periods of time to guide future behavior. This type of short-term memory has been shown to play an important role in mental disorders such as schizophrenia and therefore further investigations into the neural basis of this cognitive function may aid in the study of disease states where this cognitive function is defective.
	A likely neural correlate of working memory has been identified in the persistent neural activity observed during the memory retention intervals of various behavioral tasks. Computational and cellular physiology has suggested that this persistent activity depends on NMDA receptor activation. Indeed, pharmacological studies on both human and animal subjects have reported a significant decrease in working memory task performance following the administration of NMDA-antagonists such as ketamine. However, the task and experimental design of these previous studies have not been ideal, and have therefore only shown equivocal evidence that NMDA-antagonists impair working memory, especially its capacity. Here we aimed to determine the effect of low-dose ketamine injection (0.25-mg/kg and 0.50-mg/kg IM) on the performance of macaque monkeys on a visual sequential comparison task, a task whose performance has minimal influence from other cognitive functions besides working memory.
	All monkeys showed a detrimental effect of ketamine administration on visual working memory performance, either at higher ketamine doses or with high memory loads. There was also an effect on performance in sessions without a memory component, indicating that the effect of ketamine was no limited to working memory maintenance.
	Although the effect of ketamine on memory load varied per animal, this study provides solid evidence in support of the hypothesis that working memory maintenance is dependent on NMDA receptor integrity.

abstract: M.Sc.


title: Diatom-Inferred Changes in Effective Moisture From Gall Lake, Northwestern, Ontario, Over the Past Two Millennia

contributor:
Cumming, Brian F.
Biology

subject: Drought Paleolimnology Diatom

abstract: Thesis (Master, Biology) -- Queen's University, 2011-05-27 17:41:02.022

abstract:
The boreal forest of Canada extends across 58% of Canada’s land area providing a large range of ecosystem services including flood control, water filtration, and carbon storage. Despite conservation efforts to protect this ecosystem, the boreal region is still under stress from global stressors including climate change. Anthropogenic climate-change is expected to raise temperatures and decrease precipitation over much of the boreal region increasing the duration and magnitude of droughts. This potential change to a more arid climate could have drastic affects on water levels and stream flows across much of the boreal region. Changes in hydrology, as a consequence of anthropogenic climate change, may result in large changes to aquatic ecosystems. To assess the susceptibility of lakes to climate in northwestern Ontario over the past two millennia, sediment cores from a headwater lake were obtained from near-shore cores to reconstruct changes in drought.
The cores were located at a depth where changes in pelagic and benthic diatom assemblages (P: B boundary) were apparent in modern-day sediments because the location has been shown to be susceptible to change. The lake chosen for reconstruction was Gall Lake, a small (surface area = 9 ha, max depth = 18 m, mean depth = 8.5 m), mesotrophic lake (total phosphorus (TP) level of 12.3 μg/L, July 2008), with a gentlysloping eastern basin. This headwater lake in the Winnipeg River Drainage Basin (WRDB) is part of a hydrologically-rich region that is expected to experience increased aridity. Multivariate analysis of diatom assemblages over the past two millennia suggested that the instrumental record does not encompassed the natural variability of this system. The largest decreases in diatom-inferred (DI) depth were synonymous with iii the Medieval Climate Anomaly (MCA), a phenomenon not yet observed this far northeast in North America. The MCA has been proposed as a surrogate for climate change over the next century, therefore the prolonged  aridity observed in Gall Lake could aid in the calibration of general circulation models currently used to forecast changes in climate, as well as a scenario that can be used to develop adaptation strategies to future environmental change.

abstract: M.Sc.


title: Pain Communication in Ethnically Concordant and Discordant Dyads

contributor:
Tripp, Dean A.
Psychology

subject: Pain Ethnicity

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2011-05-30 01:16:40.34

abstract: While ethnicity is often regarded as a factor in pain experience and expression, ethnic pain research has almost exclusively focused on the intrapersonal dimension of the pain experience and failed to recognize the complex interpersonal nature of the pain experience. The Sociocommunications Model of Pain (Craig, 2009; Hadjistavropoulos & Craig, 2002; Hadjistavropoulos, Craig, & Fuchs-Lacelle, 2004) states that pain behaviours serve as both expressions of the inner experience and communications to other people, and the observer must take into account the social contexts in which the pain expression and report occur.  Research in the recent decade has documented reliable evidence that ethnic minorities suffer disproportionately from undertreatment of pain compared to nonminority, but studies examining factors that contribute to such disparities have seldom directly considered the sociocultural context in which the pain experience and assessment take place. This dissertation has two studies. The primary objective of Study 1 is to compare pain report and behaviours in an ethnically concordant versus discordant environment. The primary objective of Study 2 is to investigate the impact of ethnic concordance on the accuracy of observer’s assessment of pain. The Chinese ethnic group was chosen as the focus of the present research because it is the largest ethnic group in Canada and also this group has received little attention in ethnic pain research. Overall, results indicate that ethnic concordance between the person in pain and the observer would influence the sufferer’s pain expression and the observer’s pain assessment. The findings support the Sociocommunications Models of Pain and suggest the importance of considering the interpersonal dimension of the pain experience.

abstract: PhD


title: Detector Development and Test Facility Commissioning for SuperCDMS

subject:
Dark Matter
CDMS

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-05-30 10:39:02.976

abstract:
SuperCDMS, the next stage of the Cryogenic Dark Matter Search (CDMS), uses cylindrical germa-
nium crystals as particle detectors to measure phonon and ionization signals resulting from particle
interactions. The aim of CDMS is to identify and measure interactions from dark matter particles
(WIMPs). Phonons produced during a particle interaction are absorbed by sensors on the detector
surface and are measured through the change in the sensors' temperature dependent resistance.
Electrodes on the detector surface create an electric  eld causing charges released during an inter-
action to drift through the detector and produce an ionization signal. Surface events, which are
interactions that occur within a few  m from the electrodes, cause a reduced ionization signal due
to di usion of some of the initially hot charge carriers into the electrode. Because the ability of
CDMS to discriminate between a WIMP interaction and background radiation is based on the ratio
of phonon to ionization energies, surface events cause a signal similar to a WIMP interaction and
are currently the largest source of background.
A detector test facility at Queen's University has been commissioned to characterize detectors
and test new detector technology. Multiple detectors have been characterized and many tungsten
samples have been measured. Two sets of experiments were performed to test new detector designs.
To possibly reduce surface events, an insulating layer was deposited on a germanium detector be-
neath the electrode to prevent back di usion of charge into the electrode. To possibly simplify the
phonon sensor production process, di erent cryogenic glues were used to attach silicon wafers with
a tungsten  lm to the crystal surface and phonon propagation through these glues was measured.
The most e ective cryogenic glue for coupling tungsten samples to CDMS detectors was found to
be Araldite epoxy. Both experiments were successful at measuring interactions. Energy calibrations
were performed on both charge and phonon sensors. Further research is required to determine the
success of reducing surface events with an insulating layer.

abstract: M.A.Sc.


title: The Role of Aldehyde Dehydrogrenase 2 In Nitrate Tolerance: Investigation of Low Potency Nitrates and Cross Tolerance

contributor:
Bennett, Brian M.
Pharmacology and Toxicology

subject: Nitrate Tolerance

subject: ALDH2

abstract: Thesis (Master, Pharmacology & Toxicology) -- Queen's University, 2011-05-30 12:06:05.785

abstract:
Organic nitrates such as glyceryl trinitrate (GTN) are commonly used to treat cardiovascular disease. They are prodrugs that require bioactivation for pharmacological activity. Currently, there are two proposed pathways of organic nitrate activation: a high-affinity pathway for high-potency nitrates (GTN and pentaerythrityl tetranitate) and a low-affinity pathway for low-potency nitrates (isosorbide dinitrate (ISDN) and isosorbide mononitrate). A major limitation in the utility of organic nitrates is the rapid onset of tolerance during chronic treatment. Inhibition of the enzymes responsible for bioactivation has been put forward as the major cause of tolerance, and aldehyde dehydrogenase 2 (ALDH2) has been proposed as the primary enzyme responsible for bioactivation in the high-affinity pathway. ALDH2 activity is decreased in GTN-tolerant tissues and it has been suggested that ALDH2 inactivation is the underlying cause of GTN tolerance. However, several aspects of this hypothesis are problematic. My objective was to develop an in vivo model of ISDN tolerance and to use this model to examine the effects of chronic ISDN treatment on ALDH2 activity and on organic nitrate-induced vasodilation. The hypothesis of my research is that the reduced potency of GTN caused by ISDN tolerance is mediated by a mechanism independent of ALDH2 inactivation. ISDN tolerance was induced in rats using an in vivo model in which animals were exposed to 0.8 mg/hr ISDN for 24-96 hr. ALDH2 activity was measured in liver mitochondrial fractions and tolerance was assessed in isolated aortic preparations. There was no inhibition of mitochondrial ALDH2 activity in ISDN-treated animals. However, chronic treatment with ISDN resulted in parallel rightward shifts of both the ISDN and GTN concentration-response curves, which increased with increased duration of exposure
iii
to ISDN. Concentration-response curves for acetylcholine (ACh), sodium nitroprusside (SNP), and diethylamine NONOate were unchanged in ISDN-treated animals. The model of chronic ISDN treatment results in cross tolerance to GTN but does not affect ALDH activity. The data presented in this study indicate no role for ALDH2 in the development of nitrate tolerance.

abstract: M.Sc.


title: Greening the Greenfield: Planning Natural Heritage Systems in New Subdivisions

subject:
Planning
Halton
Natural Heritage System
Natural Heritage
Oakville
Milton
Greenfield
Subdivision

abstract: Completed in partial fulfillment of the requirements for the degree of Master of Urban and Regional Planning (M.Pl).

abstract: A masters report for the School of Urban and Regional Planning comparing Natural Heritage System plans in two new subdivisions in Oakville and Milton, Ontario.


title: Dionne Brand, Austin Clarke, and Tessa McWatt: Blackening Canada

contributor:
Varadharajan, Asha
McKittrick, Katherine
English

subject:
literature
Canadian literature
black diaspora
multiculturalism

abstract: Thesis (Ph.D, English) -- Queen's University, 2011-05-31 12:33:40.292

abstract:
This project analyzes contemporary black diasporic writing in Canada, arguing that Dionne Brand, Austin Clarke and Tessa McWatt evince a unique form of double-consciousness in their writings. Their work transforms African-American double-consciousness by locating it simultaneously within both the black diaspora and the practice of Canadian multiculturalism. The objective of this project is to offer a critical framework for situating these writers within the legacy of both Black Atlantic and Canadian cultural production. These writers do not aim to resolve their double-consciousness but rather dwell within that contradictory doubleness and hyphenation, forcing nation and diaspora to contend with one another in a discomfiting and unsettling dialogue.
These authors employ the absences of the black diaspora to imagine new forms of black cultural production, multicultural citizenship and national identity. Their works produce a grammar of diasporic double-consciousness that locates the absented origins of diaspora within Canada. Brand’s depiction of temporality and Clarke’s tracing of movement explore the continuities between nation and diaspora while re-membering neglected aspects of the history of black Canada, such as the life and death of Albert Johnson. McWatt extends this blackening of nation by depicting coalitions between diasporic, indigenous, raced and sexed subjects. These authors transform hegemonic Canadian narratives of nation by dwelling in the hyphen, while their evocation of memory, absence, trauma, and desire gives blackness new meaning and legitimacy.

abstract: PhD


title: Death Threat Letters:  Allegories of American Authorship in the Age of Terrorism

contributor:
Varadharajan, Asha
English

subject:
Authorship
Terrorism
Allegory
American Literature
Don DeLillo
Mao II
Falling Man
Richard Powers
Plowing the Dark
Philip Roth
Operation Shylock
Paul Auster
Travels in the Scriptorium
Man in the Dark

abstract: Thesis (Ph.D, English) -- Queen's University, 2011-05-31 11:44:13.321

abstract:
This dissertation examines novels that use terrorism to allegorize the threatened position of the literary author in contemporary culture.  Allegory is a term that has been differently understood over time, but which has consistently been used by writers to articulate and construct their roles as authors.  In the novels I look at, the terrorist challenge to authorship results in multiple deployments of allegory, each differently illustrating the way that allegory is used and authorship constructed in the contemporary American novel.
	Don DeLillo’s Mao II (1991), first puts terrorists and authors in an oppositional pairing.  The terrorist’s ability to traffic in spectacle is presented as indicative of the author’s fading importance in contemporary culture and it is one way that terrorism allegorizes threats to authorship.  In Philip Roth’s Operation Shylock (1993), the allegorical pairing is between the text of the novel and outside texts – newspaper reports, legal cases, etc. – that the novel references and adapts in order to bolster its own narrative authority.  Richard Powers’s Plowing the Dark (1999) pairs the story of an imprisoned hostage, craving a single book, with employees of a tech firm who are creating interactive, virtual reality artworks.  Focusing on the reader’s experience, Powers’s novel posits a form of authorship that the reader can take into consideration, but which does not seek to control the experience of the text.  Finally, I look at two of Paul Auster’s twenty-first century novels, Travels in the Scriptorium (2007) and Man in the Dark (2008), to suggest that the relationship between representations of authors and terrorists changed after 9/11.  Auster’s author-figures forward an ethics of authorship whereby novels can use narrative to buffer readers against the portrayal of violent acts in a culture that is suffused with traumatizing imagery.

abstract: PhD


title: Highly Efficient Thermal Ablation of Silicon and Ablation in Other Materials

subject:
Thermal ablation
Silicon
PZT
PMMA
Inline Coherent Imaging
Model
High intensity ablation
Feedback

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-05-31 15:02:55.547

abstract:
Laser micromachining has become increasing prominent in various industries given its speed, lack of tool wear, and ability to create features on the order of micrometres. Inherent stochastic variations from thermal ablation along with detrimental heat effects, however, limit the feasibility of achieving high precision. The high number of control parameters that make laser micromachining versatile also hinders optimization due to high exploration time. The introduction of high intensity nonlinear ablation leads to more precise cuts but at a much higher, often restrictive, cost.
The work here shows that by combining an imaging technique frequently used in ophthalmology called optical coherence tomography (OCT) with a machining platform, in situ observation of ablation can be made. This combination, known as in-line coherent imaging (ICI), allows information to be gathered about the dynamics of the ablation process. Experimental results show that quality cutting of silicon can be achieved with thermal ablation and at a wavelength of 1070 nm. This result is surprising as silicon absorbs this wavelength very weakly at room temperature. It is shown here that a nonlinear thermal dependence in absorption allows a cascaded absorption effect to enable machining. With the aid of ICI, the model shown here is able to accurately predict the thermal ablation rate and help understand the ablation process. The high quality cutting achieved allows for a more cost efficient alternative to current techniques using ultraviolet diode-pumped solid state (UV DPSS) systems.
Where thermal effects such as heat-affected zones (HAZ) cannot be overcome, high intensity nonlinear ablation allows the processing of lead zirconate titanate (PZT) for high frequency arrays (used in ultrasound applications) at speeds two orders of magnitude greater than found in the literature, and potential feature sizes (< 100 µm) in polymethyl methacrylate (PMMA) unachievable by thermal ablation. The ablation mechanism here is Coulombic explosion (CE), which is a non-thermal process. Coupled with demonstrated manual and automatic feedback abilities of ICI, the processes shown here may open up new avenues for fabrication.

abstract: M.A.Sc.


title: Excitonic Analysis of Many-Body Effects on the 1s−2p Intraband Transition in Semiconductor Systems

subject:
Many-Body
Ultrafast
Exciton
Intraband Transition
Nonlinear Optics
Semiconductor
1s-2p transition
Exciton Transition

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-05-31 15:58:27.222

abstract:
I present a detailed study of many-body effects associated with the interband 1s transition and intraband 1s-2p transition in two- and three-dimensional photo-excited semiconductors. I employ a previously developed excitonic model to treat effects of exchange and phase space filling. I extend the scope of the model to include static free-carrier screening.  I also develop a factorization scheme to obtain a consistent set of excitonic dynamical equations.  The exciton transition energies are renormalized by many-body interactions, and the excitonic dynamical equations provide simple expressions for the individual contributions of screening, phase space filling and exchange.

	The effects of exchange and phase space filling are quantified by a set of excitonic coefficients.  I first calculate these coefficients analytically by omitting screening effects.  In contrast, the screened coefficients involve multi-dimensional integrals which must be evaluated numerically.  I present a detailed discussion of the numerical methods used to evaluate these integrals, which include a novel algorithm for segmenting multi-dimensional integration regions.

	The excitonic model correctly predicts the blue shift and bleaching of the 1s exciton resonance due to exchange and phase space filling. Free-carrier screening is found to enhance these effects by lowering the exciton binding energy. In contrast, the effects of free-carrier screening on the 1s-2p transition energy are more subtle.  In the absence of free-carrier screening, exchange and phase space filling lead to a blue shift of the transition energy.  However, screening decreases the 1s binding energy faster than the 2p binding energy, which in turn decreases the transition energy.  Thus, screening effects oppose exchange and phase space filling, and the overall magnitude and sign of the 1s-2p transition energy shift depends on the free-carrier density. Specifically, for low-moderate excitation densities exchange and phase space filling can be dominated by screening, leading to a net red shift of the transition energy. The results for two- and three-dimensional systems are qualitatively similar, although the magnitudes of the shifts are much smaller in three dimensions.

abstract: M.Sc.


title: Examination of the Pore Space of a Solid Oxide Fuel Cell Electrode: A Computational Approach

contributor:
Pharoah, Jon G.
Mechanical and Materials Engineering

subject:
solid oxide fuel cell
porous electrode

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2011-06-13 15:30:00.25

abstract: A numerical model of a solid oxide fuel cell electrode is presented. Using an already established algorithm for dropping spheres as a base, alterations are made to the algorithm to increase the realism of the model. Two changes are analyzed in detail: the ability to drop pore former particles, and the use of pre-agglomerated solid particles. These changes are characterized by their impact on mean pore size, tortuosity, and effective diffusivity. As pore former volume fraction is increased, so too are mean pore size and tortuosity. A higher mean pore size has a beneficial effect on effective diffusivity due to Knudsen effects, while a higher tortuosity has a detrimental effect on effective diffusivity. The impact of mean pore size and tortuosity on diffusivity generally balances and if the impact of porosity is ignored, pore former volume fraction does not greatly affect effective diffusivity. As pore former particle size is increased, mean pore size and tortuosity also increase. Similarly to before, the effects of mean pore size and tortuosity balance. However, effective diffusivity is shown to decrease slightly with an increasing pore former particle size, suggesting a change in tortuosity has greater impact on diffusivity than a change in mean pore size. For a domain constructed with pre-agglomerated particles, the tortuosity and mean pore size were both noticeably larger than when no pre-agglomerated particles are used. Effective diffusivity was only slightly higher for a domain constructed with pre-agglomerated particles than with no pre-agglomerated particles. It is also shown that the relationship of effective diffusivity with porosity for a domain constructed with pre-agglomerated particles does not fit the correlation proposed by Berson et al. [1] for low porosity structures. A secondary goal of this work is to examine pore size measurement techniques, and present a novel technique that allows the determination of a local pore size, and therefore, a local Knudsen number. Results from the local pore size technique do not match those of the random walk method and so although the novel technique may prove to be a good starting point, it is deemed not yet suitable for use.

abstract: M.A.Sc.


title: Righting' Sex-Ed in Ontario: Adult Anxiety Over Child and Adolescent Sexual Knowledge and the Government's Undemocratic Mismanagement of Ideological Pluralism

contributor:
Burfoot, Annette J.
Sociology

subject:
Sex Education
Sexual Minority Rights
Child and Adolescent Sexuality
Religious Conservativism
Ideological Pluralism
Education Policy

abstract: Thesis (Master, Sociology) -- Queen's University, 2011-06-07 14:50:24.526

abstract:
There is no doubt that relevant and up-to-date elementary school curriculum is vital for the adequate education and socialization of youth, however, when a society is characterized by ideological pluralism and multiple visions of morality the debates over curriculum can be acrimonious and tempestuous. These debates are particularly heated when sex education is concerned since adults in Western society have a longstanding cultural discomfort with child and adolescent sexual knowledge and, more specifically, there is a strong belief that sexual knowledge compromises the “natural” innocence and ignorance of young people. This research focuses on a debate that occurred in Ontario in April and May of 2010 after the Government attempted to revise Health and Physical Education curriculum for grades 1-8, the subject that contains sex education.  Following considerable backlash, the Ontario Premier shelved the proposed revisions a mere 54 hours after the curriculum was publicized.
What led to this curriculum being received so poorly by the public and what were the contributing factors that led to this abrupt reconsideration? My research examines the debate that the new sex education curriculum produced and draws attention to the ways in which the deep seated anxieties of adults regarding adolescent and child sexual knowledge were able to overpower the voices of researchers and educational experts who were promoting the revisions. Some adults were concerned about the way that the curriculum presented a particularly liberal vision of sexual morality and argued that the new content would corrupt, mislead, and confuse youth. Though there were some individuals and groups who supported the revisions, arguing that they were relevant, necessary and overdue, their voices were not as organized or influential as the religious and social conservatives who dominated the debate. I argue that the proposed revisions to the Ontario sex education curriculum failed to gain public support because of the Government’s inability to adequately prepare for and mediate the Province’s competing liberal and conservative sexual ideologies. In my defense of the abandoned revisions, I explore how they failed to gain support not only because of the vociferous opposition of conservative religious groups who did not want to see a more liberal vision of sexual morality in the curriculum, but also due to a longstanding cultural discomfort with child and adolescent sexual knowledge and an unwillingness to fully affirm non-heterosexual identities and practices within the education system.

abstract: M.A.


title: Children's Postures While Playing at Computer Workstations

contributor:
Stevenson, Joan M.
Kinesiology and Health Studies

subject:
Children
Posture
Computer Workstation
Ergonomics
Children Posture

abstract: Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2011-06-01 10:07:46.758

abstract: There has been a significant increase in the incidence of musculoskeletal disorders (MSD) and the costs associated with these are predicted to increase as the popularity of computer use increases at home, school and work. Risk factors have been identified in the adult population but little is known about the risk factors for children and youth. Research has demonstrated that they are not immune to this risk and that they are self reporting the same pain as adults. The purpose of the study was to examine children’s postures while working at computer workstations under two conditions. One was at an ergonomically adjusted children’s workstation while the second was at an average adult workstation. A Polhemus Fastrak™ system was used to record the children’s postures and joint and segment angles were quantified. Results of the study showed that children reported more discomfort and effort at the adult workstation. Segment and joint angles showed significant differences through the upper limb at the adult workstation. Of significance was the strategy of shoulder abduction and flexion that the children used in order to place their hand on the mouse. Ulnar deviation was also greater at the adult workstation as was neck extension. All of these factors have been identified in the literature as increasing the risk for injury. A comparison of the children’s posture while playing at the children’s workstation verses the adult workstation, showed that the postural angles assumed by the children at an adult workstation exceeded the Occupational Safety and Health Association (OSHA) recommendations. Further investigation is needed to increase our knowledge of MSD in children as their potential for long term damage has yet to be determined.

abstract: M.Sc.


title: Modulation of Human Multidrug Resistance Proteins by Reactive Quinone-based Glutathione Conjugates

contributor:
Cole, Susan P. C.
Pathology and Molecular Medicine

subject:
Multidrug Resistance Protein
Glutathione
Quinone
Conjugate

abstract: Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2011-06-03 10:00:36.484

abstract: The multidrug resistance protein 1 (MRP1) and MRP2 mediate the ATP-dependent cellular efflux of a diverse set of organic molecules including many glutathione (GSH) conjugates.  In the present study, a series of GSH conjugated quinones (some of which have been shown to be toxic) were investigated for their ability to interact with human MRP1 and MRP2 using membrane vesicles enriched for these transporters.Several structurally and biologically distinct classes of endogenous (e.g. estradiol) and exogenous (e.g. hydroquinone (HQ),N-methyl-α-methyldopamine (N-Me-α-MeDA), and caffeic acid (CA)) GSH conjugated metabolites inhibited both MRP1- and MRP2-mediated vesicular transport of the prototypic MRPsubstrate (17β-estradiol-17β-D-glucuronide (E217βG)).  The relative inhibitory potencies of the metabolites with respect to MRP1 versus MRP2 differed by approximately 10-fold, with the exception of4-hydroxy-2-(glutathion-S-yl)-17β-estradiol (4-OH-2-GS-E2), which differed by 300-fold.  The catechol estradiols, N-Me-α-MeDA, and CA metabolites competitively inhibited MRP1-mediated E217βG transport and thus, are potential substrates for this transporter.  The estradiol metabolites 2-hydroxy-1-(glutathion-S-yl)-17β-estradiol(2-OH-1-GS-E2) and 4-OH-2-GS-E2were bothsubsequently shown to besubstrates of MRP1 and MRP2by means ofa substrate depletion assay and a vesicular accumulation assay using HPLC with electrochemical detection.  Transport of 2-OH-1-GS-E2 by MRP1 was inhibited by several MRP1 substrates (e.g. E217βG, leukotriene C4, and GSH disulfide) and modulators (e.g. MK571 and S-decyl-GSH).  The chemically reactiveGSH-conjugated HQ metabolites also inhibited MRP1-mediated vesicular transport of E217βGwith IC50values ranging from 3 – 30 μM.  To determine whether these compounds might modify MRP1, MRP1-enriched membrane vesicles were incubated with 2,5-(glutathion-S-yl)-hydroquinone (2,5-GS-HQ) and then immunoblotted with a MRP1-specific monoclonal antibody.An apparentreduction in the electrophoretic mobility of immuno-reactive bands relative to untreated vesicles was observed.  However, subsequent limited trypsin digests did not show any differences in the digestion profiles between 2,5-GS-HQ-treated and control vesicles, suggesting no significant differences in protein structure with respect to accessible trypsin cleavage sites.  Further experiments are needed to demonstrateMRP1 adduction by 2,5-GS-HQ.In conclusion, the data presented here are the first to show that reactive GSH-conjugated catechol and quinone metabolites can be substrates and modulators of MRP1 and MRP2 in vitro.

abstract: PhD


title: Co-delivery of Growth Factor-Loaded Microspheres and Adipose-Derived Stem Cells in A Gel Matrix for Cartilage Repair

contributor:
Amsden, Brian
Chemical Engineering

subject:
polymeric microspheres
growth factor delivery
chondrogenesis
cartilage repair
hydrogels
cell encapsulation
adipose-derived stem cells

abstract: Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2011-06-07 19:32:50.94

abstract: Co-delivery of the embedded growth factor-loaded microspheres and adult stem cells in a hydrogel matrix was studied for its potential as a cell-based therapeutic strategy for cartilage regeneration in partial thickness chondral defects.  A photopolymerizable N-methacrylate glycol chitosan (MGC) was employed to form an in situ gel that was embedded with two formulations of growth factor-loaded microspheres and human adipose-derived stem cells (ASC).  The polymeric microspheres were used as a delivery vehicle for the controlled release of growth factors to stimulate differentiation of the ASC towards the chondrocyte lineage.  The microspheres were made of amphiphilic low molecular weight (Mn < 10,000 Da) poly(1,3-trimethylene carbonate-co--caprolactone)-b-poly(ethylene glycol)-b-poly(1,3-trimethylene carbonate-co--caprolactone) (P(TMC-CL)2-PEG)). This triblock copolymer is solid below 100C, but liquid with a low degree of crystallinity at physiological temperature and degrades slowly, and so acidic degradation products do not accumulate locally.  Bone morphogenetic protein-6 (BMP-6) and transforming growth factor-3 (TGF-3) were delivered at 5 ng/day with initial bursts of 14.3 and 23.6%, respectively.  Both growth factors were highly bioactive when released, retaining greater than 95% bioactivity for 33 days as measured by cell-based assays.  To improve ASC viability within the MGC vehicle, an RGD-containing ligand was grafted to the MGC backbone. Prior to chondrogenic induction within the MGC gel, ASC viability was assessed and greater than 90% of ASC were viable in the gel grafted with cell-adhesive RGD peptides as compared to that in non-RGD grafted gels.  For ASC chondrogenesis induced by the sustained release of BMP-6 and TGF-3 in MGC gels, the ASC cellularity and glycosaminosglycan production were similar for 28 days.  The ratio of collagen type II to I per cell (normalized to deoxyribonucleic acid content) in the microsphere delivery group was significantly higher than that of non-induced ASC or with soluble growth factor administration in the culture media, and increased with time.  Thus, the co-delivery of growth factor-loaded microspheres and ASC in MGC gels successfully induced ASC chondrogenesis and is a promising strategy for cartilage repair.

abstract: PhD


title: Creating a Cycling Culture Among University Students

subject: Cycling Survey Queen's Students

abstract: Focusing on Queen’s University in the core of Kingston, Ontario, Canada, this research develops an understanding of Queen’s University students’ travel behaviour, their experiences while cycling to Main Campus, and of the best approaches to encouraging cycling or making it a more positive experience. The results of this research are grounded in a web-based survey of Queen’s University students, contextualized by a literature review. With a sample of 104 respondents, results show that females  (71 percent) were more likely than males (50 percent) to report that vehicle traffic made them feel less safe on the journey to school. However, a majority of males (69 percent) as well as females (84 percent) reported that they took detours from the most direct route in order to avoid traffic. In terms of encouraging cycling, there was no stark variability in preferences across the sexes. The most preferred options were related to bike parking management and infrastructure, specifically, security from theft and providing painted bike lanes. Three recommendations were made to Queen’s University and/or the City of Kingston based on the survey results: provide improved bike parking options, provide cycling infrastructure, and continue to plan for pedestrians yet also focus on developing a bicycle-friendly Main Campus. Next steps include: further statistical analyses including more data collection to generate a larger sample, reviews of the City of Kingston Official Plan and the Queen’s University Campus Plan, and interviews with campus and City planners to better contextualize the recommendations.