title: Modeling the Impact of Needle Exchange Programs Accounting for both HIV and HCV Infections and HIV/CV Co-Infections

contributor:
Alvarado, Beatriz
Johnson, Ana
Community Health and Epidemiology

subject: HCV HIV

abstract: Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2014-04-29 13:45:07.698

abstract:
Purpose: The aim of this study is to model the impact of needle exchange interventions on human immunodeficiency virus (HIV) and hepatitis C virus (HCV).
Methods: In order to model the impact of needle exchange interventions, behavioural effects (sexual and drug use) were translated into estimates of the number of HIV and HCV cases averted by the programs through a mathematical model.  Behavioural effects data on 63 clients had been collected previously by two Health Units in Ontario. The secondary data were analyzed to estimate the number of HIV and HCV cases averted while accounting for co-infection. A Bernoulli process model was used to estimate the number of averted cases for the condom distribution and counselling aspects of the needle exchange intervention. A modification of the Bernoulli process model was used for needle exchange interventions to account for drug use behaviours. Furthermore, this model estimated the number of cases averted while also accounting for the clients’ partner’s co-infection status. Once the number of HIV and HCV cases averted was determined, a cost analysis was conducted to estimate the net medical savings of the interventions. Costs were converted to 2011 Canadian dollars.
Results: Of the 63 clients, 21.40 HIV and 5.18 HCV cases were directly averted by the needle exchange intervention when HIV/HCV co-infection status of the partner was not taken into account. When the clients’ partners’ co-infection status was taken into account, lesser numbers were directly averted by the needle exchange intervention. The discounted medical savings averted were $6,950,028 and $6,741,331 when co-infection was and was not accounted for, respectively, for the 63 individuals.
Conclusion: The study demonstrated a different modeling method to account for HIV and HCV cases averted in the context of needle exchange. This study provides a foundation for future large scale cost-effectiveness studies.

abstract: M.Sc.


title: Recurrent Copy Number Alterations in Prostate Cancer: the Genomic Impact of PTEN Deletions and the Prostate-Specific ETS Gene Fusions

contributor:
Squire, Jeremy A.
Pathology and Molecular Medicine

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:
Copy Number
PTEN
Genomic
TMPRSS2:ERG
ETS Gene Fusions
Prostate Cancer

abstract: Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2014-04-29 14:20:06.02

abstract:
Prostate cancer is a clinically heterogeneous disease, with manifestations ranging from a rapid and often fatal progression, to indolent disease. Unfortunately, current clinicopathological criteria cannot differentiate men whose tumours require immediate and aggressive therapy from those in which active surveillance may be more appropriate.
Both PTEN deletion and ETS gene fusions are biomarkers with potential to aid in prostate cancer clinical management. In this thesis, I postulate that PTEN and fusion gene rearrangements may be associated with specific genomic changes, and might also have general impact on the genomic landscape of prostate cancer.
A meta-analysis of somatic copy number alterations (CNAs) examined 662 unique prostate cancer patient samples consisting of 546 primary and 116 advanced tumours derived from eleven publications. Normalization, segmentation and identification of corresponding CNAs for meta-analysis were achieved using established commercial software. The CNA distribution in primary disease was characterized by losses at 2q, 3p, 5q, 6q, 8p, 12p, 13q, 16q, 17p, 18q and 10q (PTEN), and acquisition of 21q deletions associated with the TMPRSS2:ERG fusion rearrangement. Unsupervised analysis identified five genomic subgroups. Parallel analysis of advanced and primary tumours indicated that PTEN genomic deletions and the gene fusion were enriched in advanced disease. A supervised analysis of PTEN deletions and gene fusions demonstrated that PTEN deletion was sufficient to impose higher levels of CNA. Moreover, the overall percentage of the genome altered was significantly higher when PTEN was deleted, suggesting that this important genomic subgroup was likely characterized by intrinsic chromosomal instability. Candidate genes in each of the recurrent CNA regions characteristic of each subgroup showed that signalling networks associated with cancer progression and genome stability were likely to be perturbed at the highest level in the PTEN deleted genomic subgroup.
Therefore classification of primary prostate cancer according to PTEN deletions, but not the gene fusion, was associated with greatly increased levels of CNA.  Collectively, the impact of PTEN loss resulted in a significantly greater frequency and extent of alteration, and heightened genomic instability with concomitant pathway disruptions.

abstract: One manuscript is currently under review, once the manuscript has been published the restriction can be lifted.

abstract: PhD


title: Arsenic in Lakes Surrounding Yellowknife: Anthropogenic or Naturally Derived?

subject: Geochemistry Arsenic

abstract:
One of the oldest and largest mines in the Northwest Territories is Giant Mine, located 5km north of the City of Yellowknife. Over Giant Mine’s 50 years of operation from 1949-1999, it has emitted approximately 20,000 tonnes of arsenic (As) emissions through roasting of arsenopyrite to obtain the submicroscopic amounts of gold. When released into the atmosphere, the As emissions bind with oxygen to form arsenic trioxide (As2O3) which, when dissolved, releases the highly toxic As3+ species into the environment. An additional byproduct of roasting is As-bearing iron (Fe)-oxide. It has been found that high levels of As within the mine property can be attributed to anthropogenic inputs through roasting (Walker et al. 2005, Wrye 2008, Bromstad 2011).
In lake sediments surrounding the Yellowknife region, collected by the Geological Survey of Canada (GSC), high levels of As have been measured. Eleven of these lake sediment samples were made into thin sections and observed through Environmental Scanning Electron Microscopic (ESEM) analysis to determine whether the As present is of natural origin or anthropogenically derived. Further Mineral Liberation Analysis (MLA) was conducted on three of the eleven samples. In all samples studied potential As-bearing phases were observed, including both natural and roaster-derived. The phases observed include arsenopyrite (FeAsS) and pyrite (FeS) of natural origin, As-sulphides and Fe-oxides containing either natural or roaster derived As, and finally As-oxides of roaster origin. MLA analysis on the remaining eight samples, as well as microXRD analysis on the synchrotron is recommended in order to develop more definitive and quantitative conclusions.


title: Investigating the sophistication of rapid corrective responses in the upper limb during reaching and postural control

contributor:
Scott, Stephen H.
Neuroscience Studies

subject:
Sensory Feedback
Decision
Reaching
Motor Control

abstract: Thesis (Ph.D, Neuroscience Studies) -- Queen's University, 2014-04-29 16:54:12.489

abstract:
Everyday movements, such as reaching for a drink of water or typing on a keyboard highlight the relative ease with which we move and interact with our surroundings. However, the success of these skilled movements depends on the motor system’s ability to consider a variety of factors, such as the goal of the behavioral task, the surrounding environment and the physical properties of the musculoskeletal system. Recent theories of voluntary motor control, namely optimal feedback control, suggest that such skilled motor behavior is achieved through sophisticated feedback control. This thesis investigates one physiological implication of this theory. Specifically, we hypothesize that rapid feedback responses following mechanical perturbations possess many of the functional attributes thought to be reserved for voluntary control because these two systems have contributions from similar neural substrates (eg. motor areas in cortex).
Our studies were specifically designed to investigate rapid feedback responses during the long-latency epoch, which occurs between 50-100ms following a mechanical perturbation. Consistent with our hypothesis, we found that the sophistication of the long-latency response rivals that of voluntary control. In our first study (Chapter 2) we examined if rapid feedback responses were sensitive to features of the end target. We found that muscle activity during the long-latency epoch was modulated by the size/shape of the end. In our second study (Chapter 3) we observed flexible responses in muscle activity during the long-latency epoch that reflected rapid ‘decisions’ during online control regarding how to navigate around obstacles in the environment as well as how to select amongst multiple potential goals. In our final study (Chapter 4) we examined if rapid feedback responses in the shortened muscle parallel the sophisticated responses observed in the lengthened muscle. We found that unloading a pre-excited muscle elicited sophisticated inhibitory responses, including knowledge of limb mechanics and rapid target selection, during the long-latency epoch that are comparable to the excitatory responses observed during loading.
Taken together, the studies presented in this thesis demonstrate that the responses in the
long-latency epoch reflect several functional attributes typically reserved for voluntary control.

abstract: PhD


title: Physical modelling of landslides in loose granular soils

contributor:
Take, W. Andy
Civil Engineering

subject:
landslides
physical modelling
static liquefaction

abstract: Thesis (Ph.D, Civil Engineering) -- Queen's University, 2014-04-29 16:45:11.335

abstract:
The catastrophic consequences associated with landslides necessitate predictions of these hazards to be made with as much certainty as possible.  However, the often complex nature of these events make predictions highly challenging.  In this thesis, a number of hypotheses related to the triggering mechanisms and subsequent consequences of landslides in a loose-granular soil were investigated.   The investigation was conducted using small-scale geotechnical centrifuge models, and a new flume facility developed to examine landslide behavior in a reduced-scale model.

The first hypothesis explored in this research was that static liquefaction might preferentially occur in the saturated granular soil located at the base of the landslide rather than the well-drained inclined portion of the slope.  Using a geotechnical centrifuge model, it was found that a small initial toe failure did act as a monotonic loading trigger to shear the loose contractile saturated sand at the base of the slope and caused liquefaction to occur.

The second hypothesis investigated whether the consequences of a landslide triggered under elevated groundwater antecedent conditions are higher than scenarios under drier antecedent conditions.  Results from five centrifuge models subjected to different antecedent groundwater conditions show that higher groundwater conditions can result in landslides with velocities about three times higher and travel distances eight times higher than low antecedent conditions.

The third hypothesis investigated the influence of slope inclination on landslide consequences.  Seven geotechnical centrifuge models were built and tested, comparing the consequences of  landslides triggered in 20° and 30° sloped models with different groundwater conditions.  The results of these tests found that the influence of slope angle on the mobility consequences of a triggered landslide are highly dependent on the antecedent groundwater conditions.  The most significant case was under high groundwater conditions, where the shallower 20° slope travelled twice the distance and speed of the steeper 30° slope.

A new flume facility was developed to examine landslide behaviour in a reduced-scale model, and a direct comparison was made to one of the centrifuge models from the research.  The comparison demonstrated the challenges associated with using reduced-scale models to study suction-dominated problems such as hydraulically-induced landslides in loose granular soils.

abstract: PhD


title: Acute Toxicity of Diisoheptyl Phthalate and Diisononyl Phthalate to Oryzias latipes

subject:
Aquatic Toxicology
Fish
Oryzias Latipes
phthalates
DINP
DIHepP
Diisononyl phthalate
Diisoheptyl phthalate

abstract: Phthalates are industrial chemicals used primarily as plasticizers to increase the flexibility of high molecular-weight polymers. These compounds are not covalently bound to the polymeric matrix but are instead distributed between the macromolecules of the polymer. Therefore, it is highly possible for them to leach out, inducing subsequent environmental contamination. It is important to learn more about how these toxicants are affecting the environment and vertebrate health. Diisoheptyl phthalate (DIHepP) and diisononyl phthalate (DINP) are among the list of substances that are being assessed by Environment Canada’s Chemical Management Plan. This study examines the effect of DIHepP and DINP on the Asian fish Oryzias latipes because it is subject to phthalate contamination in its natural habitat when phthalates leach out of plastic substances into the surrounding environment. At 1 day post hatching, fish were exposed to a range of environmentally relevant, low concentrations of DIHepP (0.037-0.3 µL/L) and DINP (0.012-0.1 µL/L) under semi-static conditions for 7 d. None of the treatments significantly induced mortality or malformation. Gene expression analysis was performed to assess possible endocrine disruption of these compounds. The transcripts of interest include deiodinase iodothyronine type 1 (dio1), thyroid hormone receptor β (trβ), steroidogenic acute regulatory protein (star), steroid 5-alpha reductase type 2 (srd5α2), and cytochrome P450 aromatase (cyp19β). The exposure did not have a statistically significant effect on gene expression. Taken together, these results indicate that exposure to DIHepP and DINP do not significantly affect mortality, malformation, or endocrine disruption in O. latipes at the tested concentrations.

abstract: Environment Canada, Royal Military College of Canada


title: Increasing Organic Agriculture in Ontario Using Local Food Distribution Systems

subject:
Organic Agriculture
Community Supported Agriculture
CSA
Local Food Distribution
Local Food
Local Food Initiative
Ontario Food Policy
Organic Agriculture Policy

abstract: Various studies have found that organic agricultural methods produce healthier soils with a higher content of organic matter, cause less soil erosion and create less environmental pollution from chemical fertilizers and pesticides. Farms that use organic production methods may also have a greater biodiversity of birds, predatory insects, soil organisms and plants, and emit less greenhouse gases due to lower fossil energy inputs compared to conventional agricultural methods. Studies have also found that purchasing local food reduces the greenhouse gas emissions associated with food transportation, and benefits rural communities and economies. This study seeks to promote organic production methods and local food systems in order to take advantage of the environmental and social benefits of both in order to decrease the negative environmental impact of our food production and distribution systems. The purpose of this study is to determine whether supporting the development of certain types of local food distribution systems can increase the amount of organic agricultural production in Ontario. The main objective of this study is to develop policy recommendations that may be effective in increasing the availability of local, organic food in Ontario and in supporting the development of the local food distribution systems that are used most by organic producers. A high percentage of organic farms use a Community Supported Agriculture (CSA) sales method and 75 percent of CSA farms in Ontario use organic production methods. CSA farms are mainly concentrated in five areas across Ontario. These five areas each have an established customer base, existing infrastructure, and individuals who have knowledge of alternative sales methods and distribution systems. These areas also have a strong network of communication between local producers and the communities that exist in these areas are educated about local food. All of these factors increase the success of a potential local food distribution system. For these reasons, the five areas identified in this study are prime locations for developing local food distribution systems.


title: Predicting Femoral Geometry from Anatomical Features

contributor:
Stewart, James
Computing

subject:
statistical shape atlas
anatomical features

abstract: Thesis (Master, Computing) -- Queen's University, 2014-04-29 21:53:10.809

abstract:
Knee replacement surgery is a common orthopaedic procedure that greatly benefits from a three-dimensional geometric representation of a patient's knee bone obtained from MR or CT data. The use of these image modalities pose the following challenges: (i) high imaging cost; (ii) long wait times; (iii) limited availability and (iv) in the latter, large exposure to ionizing radiation. Traditional approaches based on planar X-ray radiography are significantly less prone to these issues; however, they only provide two-dimensional information.

This work presents a proof of concept study for generating patient-specific femoral bone shapes from a statistical shape atlas using anatomical features acquired from calibrated X-ray radiographs. Our hypothesis was: three-dimensional geometry can be reconstructed, within 2 millimeters RMS, by identifying features on two calibrated radiographs. We illustrate the feasibility of our approach with regards to acquiring features and the viability of reconstructing patient-specific bony anatomy. A set of reliable and relevant features is identified for which an acquisition protocol and user-interface was devised to minimize inter-observer variability. Both the data and methods used to construct the atlas are discussed as well generating shapes from features. The reconstructions accuracy was comparable to, albeit lower than, competing approaches that rely on two-dimensional bony contours.

abstract: M.Sc.


title: Investigation of Softening Instability Phenomena Under Simulated Infinite Slope Conditions in Centrifuge Tilting Table Tests

subject:
Centrifuge
Instability
Infinite Slope
Slope Stability
Physical Modelling
Tilt Table
Geotechnical
Soil

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2014-04-29 22:01:36.786

abstract:
Element test results reported in the literature under both triaxial and plane strain conditions indicate that loose saturated granular specimens can experience softening instability at stress ratios lower than what might otherwise be expected given the critical state friction angle of the soil. The region of potential softening instability in stress-space is often explained using the framework of the instability line. This phenomenon is particularly relevant to shallow slopes of 1 to 2 m depth. However, the practical realities of sample preparation for triaxial testing make performing tests below 20 to 30 kPa of confining stress exceptionally difficult.
In this thesis, the development of a centrifuge tilt-table test device is described which aims to test the behaviour of loose granular slopes under stress paths of increasing slope inclination or increasing pore water pressure. A system of instrumentation including pore pressure transducers, inclinometers, displacement transducers, and high-resolution cameras was designed to monitor the behaviour of the slope model. The development of a system to provide a controlled groundwater level within the slope model proved to be particularly challenging. The results of two competing design concepts are presented for the water boundary condition and discussed.
The centrifuge tilt-table is used to compare the physical response of a slope to the behaviour predicted by the infinite slope and softening instability models using scale model centrifuge testing.  If softening instability is a rigorous concept, it should be the primary observed failure mechanism as it will occur at a stress state below the failure line.  Tests were performed on loose Ottawa F110 sand at 1g, 20g and 40g and 60g.  Deviatoric strain-softening was observed in loose dry sand.  The softening instability event resulted in a rapid increase in shear strain at constant shear stress while the soil was at a stress state below the failure envelope.  Any soil that can experience softening instability (i.e. granular, loose, saturated, and behaves undrained) will undergo two failures: one caused by deviatoric strain-softening (softening instability) and a second caused by shear failure at a larger slope angle.

abstract: M.A.Sc.


title: Looking Beyond the Surface: The Politics of Two Grade Ten History Textbooks in Ontario

contributor:
Bruno-Jofré, Rosa
Education

subject: Politics Textbooks

abstract: Thesis (Master, Education) -- Queen's University, 2014-05-01 16:11:08.08

abstract: The study of history has always been very significant to me. My early and most vivid exposure to the subject occured when I was in grade ten. At the time, I felt that a part of me was disconnected from the content we were taught. I was not able to identify myself with the history narrated in the textbooks. I began to examine history from a critical perspective, and thought about whose history was being taught. Textbooks play a powerful role in the way students understand history and in their cultural and political formation. This study is theoretically framed by critical race theory and post-colonial theory. I compared two ministry approved grade ten history textbooks published under two different governments to examine how the history of non-white minority groups has been represented and integrated into the narrative of the textbooks. I investigated the representation of Black Canadians, Chinese Canadians, Japanese Canadians, Vietnamese Canadians, and South Asian Canadians. Furthermore, I analyzed how the government's educational objectives and their differing agendas intersected with the content in the textbooks. Overall I found that the minority groups I studied were marginalized in the first textbook I looked at, however in the second textbook they were provided much wider representation.

abstract: M.Ed.


title: Multi-hop Localization in Large Scale Deployments

contributor:
Hassanein, Hossam S.
Taha, Abd-Elhamid M.
Computing

subject:
Localization
Sensor Networks
Internet of Things
Mobile Anchor
Positioning
Multi-hop

abstract: Thesis (Ph.D, Computing) -- Queen's University, 2014-04-30 01:53:55.817

abstract:
The development of Wireless Sensor Networks (WSNs) is enabled by the recent advances in wireless communication and sensing technologies. WSN have a wide range of scientific and commercial applications. In many applications the sensed data is useless if the location of the event is not associated with the data. Thus localization plays a substantial role in WSNs. Increased dependence on devices and sensed data presses for more efficient and accurate localization schemes. In many Internet of Things (IoT) deployments the area covered is large making it impossible to localize all devices and Sensor Networks (SNs) using single-hop localization techniques. A solution to this problem is to use a multi-hop localization technique to estimate devices' positions. In small areas SNs require at least three anchor nodes within their transmission range to estimate their location.
Despite numerous existing localization techniques, the fundamental behavior of multi-hop localization is, as yet, not fully examined. Thus, we study the main characteristics of multi-hop localization and propose new solutions to enhance the performance of multi-hop localization techniques. We examine the assumptions in existing simulation models to build a more realistic simulation model, while studying and investigating the behavior of multi-hop localization techniques in large scale deployments before the actual deployment. We find that the introduced error follows the Gaussian distribution, but the estimated distance follows the Rayleigh distribution. We use the new simulation model to characterize the effect of hops on localization in both dense and sparse multi-hop deployments. We show that, contrary to common beliefs, in sparse deployments it is better to use long hops, while in dense deployments it is better to use short hops. Using short hops in dense deployments generates a large amount of traffic. Thus we propose a new solution which decreases and manages the overhead generated during the localization process. The proposed solution decreased the number of messages exchanged by almost 70% for DV-Distance and 55% for DV-Hop. Finally, we utilize mobile anchors instead of fixed anchors and propose a solution for the collinearity problem associated with the mobile anchor and use Kalman Filter (KF) to enhance the overall localization accuracy. Through simulation studies, we show that the scheme using a Kalman Filter decreases the estimation errors than using single direction by 31% and better than using weighted averages by 16% . As well, our new scheme overcomes the collinearity problem that appears from using mobile anchor nodes.

abstract: PhD


title: Predictive Radio Access Networks for Vehicular Content Delivery

contributor:
Hassanein, Hossam S.
Electrical and Computer Engineering

subject:
predictive resource allocation
adaptive video streaming
mobility-aware
channel predictability
radio access networks

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2014-04-30 06:15:34.31

abstract:
An unprecedented era of “connected vehicles” is becoming an imminent reality. This
is driven by advances in vehicular communications, and the development of in-vehicle
telematics systems supporting a plethora of applications. The diversity and multitude
of such developments will, however, introduce excessive congestion across wireless
infrastructure, compelling operators to expand their networks. An alternative to
network expansions is to develop more efficient content delivery paradigms. In particular,
alleviating Radio Access Network (RAN) congestion is important to operators
as it postpones costly investments in radio equipment installations and new spectrum.
Efficient RAN frameworks are therefore paramount to expediting this realm
of vehicular connectivity.
Fortunately, the predictability of human mobility patterns, particularly that of vehicles
traversing road networks, offers unique opportunities to pursue proactive RAN
transmission schemes. Knowing the routes vehicles are going to traverse enables the
network to forecast spatio-temporal demands and predict service outages that specific
users may face. This can be accomplished by coupling the mobility trajectories with
network coverage maps to provide estimates of the future rates users will encounter
along a trip.
In this thesis, we investigate how this valuable contextual information can enable RANs to improve both service quality and operational efficiency. We develop a collection
of methods that leverage mobility predictions to jointly optimize 1) long-term
wireless resource allocation, 2) adaptive video streaming delivery, and 3) energy efficiency in RANs. Extensive simulation results indicate that our approaches provide
significant user experience gains in addition to large energy savings. We emphasize
the applicability of such predictive RAN mechanisms to video streaming delivery, as
it is the predominant source of traffic in mobile networks, with projections of further
growth. Although we focus on exploiting mobility information at the radio access
level, our framework is a direction towards pursuing a predictive end-to-end content
delivery architecture.

abstract: PhD


title: Peptide inhibitors of angiogenesis in endometriosis and the female reproductive system

contributor:
Tayade, Chandrakant
Anatomy and Cell Biology

subject: Endometriosis Reproduction Angiogenesis

abstract: Thesis (Ph.D, Anatomy & Cell Biology) -- Queen's University, 2014-05-01 14:42:32.655

abstract:
Endometriosis, characterized by the growth of endometrium outside the uterine cavity, is a disease which causes pelvic pain, inflammation and associated with infertility. Endometrium, which exits the uterus through retrograde menstruation, must establish a new blood supply as it attaches and invades into ectopic tissues to form an endometriosis lesion. Angiogenesis is therefore essential in endometriosis disease progression. The inhibition of blood vessel growth by anti-angiogenic agents is a potential strategy to manage endometriosis disease progression. This thesis investigated angiogenesis of endometriosis lesions, and evaluated a novel anti-angiogenic peptide as a potential therapeutic to manage endometriosis. An atlas on the microscopic anatomy of the pregnant mouse uterus is also presented. Synuclein-γ (SNCG), a protein involved in cellular proliferation, was found to have elevated expression in endothelial cells of endometriosis tissue compared to eutopic endometrium. In an alymphoid xenograft mouse model of human endometriosis, where human endometrium is engrafted into the peritoneal cavity of Rag2-/-/IL2r-/- female mice, peptide inhibition of SNCG resulted in reduced vascularization of endometriotic lesions. This study indicates that SNCG has a potential role in angiogenesis of endometriosis lesions. Using the same alymphoid mouse model, we evaluated the effect of an anti-angiogenic thrombospondin-1 mimetic peptide, ABT-898, on angiogenesis of endometriotic lesions. ABT-898 inhibited endothelial cell proliferation and tube formation in vitro. Mice treated with ABT-898 showed reduced vascularity of endometriosis lesions compared with control. Angiogenesis is also an essential process in the female reproductive system. Females with endometriosis are of reproductive age, so it is essential to establish that anti-angiogenic therapies do not
iii
interfere with reproduction. We evaluated the effect of ABT-898 on angiogenesis in the female reproductive tract in non-pregnant mice. ABT-898 did not affect estrous cyclicity, or vascularity of the uterus or ovary in non-pregnant animals. ABT-898 did not alter litter size or pup weight when given to pregnant mice throughout gestation. In summary this thesis implicated a role for SNCG in angiogenesis of endometriosis lesions, and found that ABT-898 could be a useful therapeutic to manage endometriosis disease progression as it reduces angiogenesis of endometriotic lesions, while having no observable effect in reproductive organs.

abstract: PhD


title: A Paleolimnological Assessment of Cladoceran Assemblage Changes in Two Lakes from Northern Ontario’s “Ring of Fire”

subject:
Northern Ontario
Paleolimnology
Climate Change

abstract: The Northern Ontario “Ring of Fire” (RoF) contains vast mineral deposits that have sparked considerable interest over the past decade, regarding regional mining and infrastructure development. Little is known about the current limnological or ecological changes occurring in this area prior to industrial development. Paleolimnological techniques were therefore used to assess changes over the past ~150 years in the cladoceran sedimentary assemblages, production and predation regimes of two strategically selected lakes. This study provides historical context on ecological variability in the region, prior to the onset of development. Sediment cores were obtained from Eabamet and McFaulds lakes located near the RoF during the summer of 2012. Significant shifts were present in the cladoceran assemblages of both lakes, with increasing relative abundances of pelagic taxa in the more recent sediments. A cluster analysis of the McFaulds Lake assemblage data detected a primary split around the mid-1990’s, consistent with warming air temperature in the vicinity of Hudson Bay. Trends in production coincide with recent warming, as inferred chlorophyll-a increased in the recent sediments, likely due to a longer ice-free season providing an extended growing period for phytoplankton. Average Bosmina mucro length also increased in the recent sediments. In contrast, the cluster analysis of the cladoceran sedimentary assemblages in Eabamet Lake experienced an earlier change ~1960, prior to the recent warming, and is likely associated with the construction of an upstream dam in the late-1950’s.  Finally, a lack of change in the Bosmina size structure of Eabamet Lake suggests a stable predation regime over ~150 years. This investigation provides long-term ecological information to an under-studied region and demonstrates current stressors on aquatic communities in the RoF.

abstract: NSERC


title: Investigation of High Surface Area Artificial Floating Wetlands for Removal of Pollutants in Nutrient-rich Waters

contributor:
Wootton, Brent
Anderson, Bruce
Civil Engineering

subject:
E.coli
Phosphorus
Nitrogen
Artificial Floating Wetlands

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2014-04-30 12:57:03.197

abstract:
Beneficial management practices for controlling and managing pollutant loadings from entering source waters are essential to preserving the natural habitat of lakes and rivers. Artificial Floating Wetlands (AFWs) are a promising technology, when applied with other beneficial management practices, for the removal of water borne contaminants in urban and agricultural runoff.

To evaluate AFWs for their application for nutrient-rich water remediation, a pilot scale study was assessed at the Centre for Alternative Wastewater Treatment in Lindsay Ontario. Fifteen ponds, averaging in size from 7.2 m width to 9.7 m length to 3.8 m depth were divided into two controls and three treatments, each with three replicates. The controls were not covered with AFWs and were used for comparative purposes while the treatments had AFW coverage averaging 67% of the total surface area of each pond. The treatments and controls received varying inputs of simulated stormwater runoff during the study. This study was used to determine the effects of high surface area coverage of AFWs on temperature, pH, DO and ammonia.

A lab scale study was designed to investigate the results obtained from the pilot study and to assess the effectiveness of 100% AFW coverage for nutrient-rich water treatment. The study consisted of twelve 150 L containers, with four of the containers covered with the AFW, four without coverage and the final four with coverage without vegetation. Water quality parameters including phosphorus, nitrogen, E.coli, pH and temperature were tested on a weekly basis for two five week retention periods.

Results from these studies suggest that AFWs can provide a valuable method of treatment when combined with other beneficial management practices. The pilot scale study demonstrated that AFWs inhibit algae growth and create a cooler environment below the wetland surface. Results from the second study indicate AFWs have a much better and quicker removal of phosphorus and ammonia when compared to the treatment with coverage without vegetation. E.coli levels were completely reduced within the water column for all treatments during the testing period.

abstract: M.A.Sc.


title: Structural and Steady-State Thermal Experimental Investigations of an Insulated Sandwich Panel

contributor:
Fam, Amir Z.
Civil Engineering

subject:
GFRP
Sandwich Panel

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2014-05-06 13:32:38.896

abstract:
Concrete-Insulation-Concrete Sandwich Panels with Glass Fibre Reinforced Polymer (GFRP) shear connectors can be a solution to increasing energy efficiency in building envelopes, while also providing many architectural, structural, and economic benefits for building designs.  This study consists of extensive experimental investigation of the shear and thermal properties of a unique sandwich panel design, incorporating GFRP shear connectors and a concrete “stud” system.  The goal of this study is to expand upon the knowledge of alternative connectors’ effect on structural and thermal properties of sandwich panels, and to develop a thermally, structurally, and economically efficient panel.

In the structural phase fifty 254x254x900 mm specimens representing segments of the precast sandwich wall, comprising two concrete wythes and a concrete stud surrounded by insulation foam, were tested in a double shear configuration.  Three types of GFRP connectors produced from available sand-coated and threaded rods were tested and compared to conventional steel and polymeric connectors.  GFRP connector diameters varied from 6 to 13 mm, and spacing varied from 80 to 300 mm.  Both circular and rectangular cross-sections were examined, along with various end treatments to compare with simple straight embedment.  The shear strength of GFRP connectors ranged from 60 to 112 MPa, significantly higher than polymeric connectors but lower than steel connectors.  As the connectors bridged a small gap of insulation between the concrete wythe and stud, their shear strength was lower than manufacturer reported values due to the presence of some bending.  Varying the size, spacing, cross-section shape or end treatment of connectors had insignificant effect on their strength.  The connectors failed by longitudinal delamination then transverse shear, but did not pull out of the concrete wythe.  Adhesion bond between concrete and insulation was significant and contributed about 28% of resistance, but was too variable for use in design.

In the thermal testing phase, ten 254x1550x2400 full-scale specimens were tested in a purpose-built hot box apparatus under steady-state conditions.  GFRP connectors showed minimal thermal bridging regardless of cross-section area or spacing, while steel connectors demonstrated significant thermal bridging in recorded temperatures despite a smaller cross-section area, and were clearly visible in thermal imaging.

abstract: M.A.Sc.


title: Inline Coherent Imaging Applied to Laser Micromachining

subject:
Laser marking
Optical metrology
3D laser machining
Galvanometer
Depth monitoring/feedback
Laser machining
Coherent imaging
SD-OCT

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2014-04-30 13:56:35.793

abstract:
Laser processing has the advantage of minimal sample contact and thus little tool wear over time compared to conventional machining. However, this leads to the difficulty of real-time depth monitoring and control. To help understand the process and achieve automation of laser micromachining, a coherent imaging technique adapted from spectral domain optical coherence tomography (SD-OCT) is applied “inline”with a machining laser to monitor the depth changing information. The axial resolution of the inline coherent imaging (ICI) system is 7–8  microns and the acquisition rate is up to 230 kHz. The capture time is as low as 1.5 microseconds.
3D laser machining usually requires ultrafast lasers and homogeneous materials. With ICI, a feedback system is developed for 3D sculpture suitable even for heterogeneous materials without any sophisticated material characterization. 3D patterns with sizes up to 1 mm × 1 mm × 0.2 mm are sculpted in bone and wood with a ps UV laser. 3D patterns with sizes up to 6 mm × 6 mm × 2 mm are sculpted in bone with a CW IR laser.
Many laser applications require high scan speed facilitated by scanning optics. The versatility of ICI is also demonstrated in a galvo-telecentric beam delivery system. ICI is used in a process of trench (as long as 10 mm) etching of steel to monitor the intrapulse and interpulse morphology changes as well as the sweep-to-sweep (up to 36 sweeps) depth changes. High scan speed (up to 375 mm/s) trench etching of silicon are also monitored and the parameter space is explored without destructive post-processing.
Motion during imaging capture time (>1.5 microseconds) may cause contrast degradation. To reduce the motion artifacts, preliminary experiments on stroboscopic ICI based on a kHz pulse repetition rate femtosecond laser are described. By “sampling” the motion of the machining front discretely with a “sampling time” as short as the imaging pulse duration, our results demonstrate that stroboscopic ICI is a promising way to improve the ICI contrast against motion artifacts.

abstract: M.A.Sc.


title: Designing for A Safer Public Housing Community: A Case Study of Chester Le, Toronto

subject:
public housing
community safety
environmental design
urban planning

abstract: Crime and fear of crime are major concerns confronting public housing tenants today. Public housing tenant population is usually composed of groups of people who have traditionally been found to be more vulnerable to violence and have greater fear of criminal victimization. In response to the increasing level of fear of crime and urban violence, a physical structure-based approach to crime prevention and management of urban spaces, Crime Prevention through Environmental Design (CPTED), was emerged and prevailed in the planning profession in recent years. This research project examined the links between the characteristics of the built environment, fear of crime, and community safety in a public housing project, the Chester Le community, located in L’Amoreaux neighbourhood in northeast Toronto. The objective of this study was to identify and examine the potential impact of physical design features on the perception of safety in Chester Le and determine how the perception of safety can be improved by modifying these design features. The research used evaluation criteria established in the Metropolitan Action Committee on Violence Against Women and Children’s (METRAC’s) Community Safety Audit (CSA) tool and the City of Toronto’s safety design guideline, A Working Guide for Planning and Designing Safer Urban Environments, to provide specific recommendations to improve the community safety around the public housing areas in Chester Le, and make informed policy recommendations for TCHC to better address community safety issues in general.


title: Automatic P-wave Picking of Microseismic Events in Underground Mines

contributor:
Daneshmend, Laeeque K.
Dineva, Savka
Mining Engineering

subject: Mining Seismology

abstract: Thesis (Master, Mining Engineering) -- Queen's University, 2014-04-30 21:45:13.741

abstract: This thesis investigates microseismic P-wave arrival time detection performance of automatic picking algorithms, as well as the handpicking performance of human experts. The data set used in this project was collected from Malmberget mine (LKAB, Sweden) and the handpicked P-wave arrivals were prepared by multiple expert analysts from the Institute of Mine Seismology (IMS). Characterization of the event records in the data set was completed including the magnitude distribution of the events, noise content of the traces, and frequency spectrum of the traces. Three promising automatic P-wave picking algorithms from previous seismological research were investigated: the short-term average to long-term average ratio detector (STA/LTA), the characteristic function detector (CF), and the autoregressive modelling detector (ARfpe). Several versions of each algorithm were implemented, and the most promising versions were tested on the full dataset of microseismic events. The STA/LTA algorithm and CF algorithm were superior to the ARfpe algorithm in terms of accuracy and percentage of false negatives (missed P-wave arrival time picks). The analyst P-wave arrival times were compared and statistical distributions of the analyst P-wave arrival time differences were studied. The analyst P-wave arrival time difference and algorithm P-wave arrival time difference were defined as the mean analyst P-wave arrival time minus the specific analyst P-wave arrival time pick or the specific algorithm P-wave arrival time pick. The analyst and algorithm P-wave arrival time differences were combined into separate statistical distributions and compared. The analyst P-wave arrival time distribution lengths varied by a factor of 5, and the percentage of outliers in the distribution varied between 12% and 32%. The STA/LTA algorithm had comparable distribution statistics to the worst analyst P-wave arrival in terms of median value, distribution length, and percentage of outliers. However when the number of traces with automatic P-wave picks within the analyst handpicking range was calculated the STA/LTA algorithm had only 32.0% of picks and the CF algorithm had only 11.6% of picks.

abstract: This thesis contains data from Malmberget Mine (LKAB) and the report is currently being reviewed by the Mine Management for publication approval. The thesis has passed a closed defense but the mine has not finished reviewing the thesis yet. It needs to be approved by the mine before publication.

abstract: M.A.Sc.


title: Polarimeter for an Accelerated Spheromak

subject:
Energy
Plasma
Magnetized Target Fusion
Spheromak
Polarimeter
Magnetic Field
Fusion

abstract: Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2014-04-30 22:17:18.648

abstract:
A three-beam heterodyne polarimeter has been designed and constructed to measure line-integrated density and Faraday rotation of accelerated spheromak plasmas in the Plasma Injector 1 and 2 devices (PI-1, PI-2) at General Fusion Inc. Faraday rotation is a function of the local magnetic field and electron density. Therefore, the polarimeter has the potential to provide information on the internal magnetic field of the plasma.

A typical spheromak is about 1m in length and is accelerated to speeds on the order of 100km/s. At a bandwidth of 1MHz, the polarimeter can axially resolve the spheromak down to about 10cm. The polarimeter uses a $\nit{CO}_2$ laser that produces a Faraday rotation signal of about $0.5\degrees$ for a typical plasma with density and magnetic field on the order of $\ee{21}\mmt$ and 1T. The Faraday rotation measurement noise floor for a null signal is about $0.1\degrees$.

Two important sources of Faraday rotation error are the ellipticity and collinearity of the plasma-immersed beams. These error sources are examined by sending the plasma beams through a rotating optic to mimic the path through a dense, magnetized plasma. The error due to the ellipticity effect has been reduced to below the noise floor by careful alignment and use of zero phase reflectors that minimize elliptical polarization of the beams.

Collinearity error has been greatly improved by aligning the beams with a rotating ZnSe wedge. Measurements after the alignment match well with a model Faraday rotation signal generated from magnetic probe measurements. However, beam collinearity continues to be a significant source of error. For regions with strong density gradients, the size of this error can be on the order of the signal magnitude.

For future work, steps should be taken to improve the alignment of the two plasma-immersed beams, and to shorten the length of the beam path to further reduce the beam collinearity error.

abstract: PhD


title: A Laboratory Examination of Down-slope Bentonite Erosion in Geosynthetic Clay Liners

contributor:
Rowe, Kerry
Civil Engineering

subject:
downslope erosion
slope
composite liner
exposed liner
GCL

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2014-05-01 10:16:14.05

abstract:
Geosynthetic Clay Liners (GCLs) are commonly paired with a geomembrane and used as part of a composite liner system for landfill barriers.  Under some circumstances, leaving a composite geomembrane/geosynthetic clay liner exposed to solar radiation in the field has been shown to cause shrinkage of the underlying GCL.  Recent field studies have shown that leaving a composite liner exposed can also lead to down-slope erosion of bentonite from the GCL due to the down-slope movement of moisture.

To investigate the factors that can affect the onset of bentonite erosion in a GCL an experimental technique was developed to reproduce similar erosion in the laboratory.  The test method simulates the features that occur with the erosion of bentonite caused by down-slope migration of evaporative water in the field.  One needle-punched GCL was tested to examine the factors that can affect the onset of erosion of bentonite particles with the flow of water.  The factors examined include the effect of the initial wet/dry cycle, water source chemistry, flow rate, slope, prior cation exchange, and the effect of no drying phase in the test cycle.

Ten different manufactured GCL products were tested to examine the effect of material properties on the erosion of bentonite from a GCL.  The material properties of the products tested differed in terms of the type of carrier and cover geotextiles, bentonite (powdered, fine and coarse grained, and some with a polymer enhancement additive) and the presence of a polypropylene coating over the geotextile.

It was found that the most critical factor to trigger the onset of bentonite erosion was the water source chemistry, with the tests that simulated the evaporation and condensation of water (deionized water) below an exposed composite liner leading to the formation of major erosion features.  The results of the laboratory testing program also show that erosion features are more visible in products with white coloured geotextiles.  The products containing a polypropylene coated geotextile and polymer enhanced bentonite slowed or, in some cases, prevented erosion features from developing.

abstract: M.A.Sc.


title: Arsenic Speciation and the Controls on its Release in Contaminated Sediments and Corresponding Toxicological Effects at Giant Mine, NWT

contributor: Geological Sciences and Geological Engineering

subject:
Geochemistry
Giant Mine
Toxicity
DGT
Minipeeper
Arsenic

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-05-01 11:47:59.482

abstract:
Arsenic (As) contamination presents an ecosystem and human health risk at Giant Mine, a historic gold mine near Yellowknife, NWT currently undergoing the final stages of assessment for remediation.  Arsenic concentration is elevated in sediments at Giant Mine due to contamination from several forms of mine waste including flotation tailings, roaster calcine and impoundment spills. The Giant Mine Remediation Project has stated aims to remediate the surface of the site, including Baker Creek which runs through the property, to a condition that is a productive environmental habitat and spawning ground.
Environmental scanning electron microscope (ESEM) and synchrotron-based micro- X-ray Absorption Near Edge Spectroscopy (µXANES), micro-X-ray fluorescence (μXRF) and micro-X-ray diffraction (μXRD) techniques were employed to characterize the As-host phases and determine the solid-phase speciation of As in mine waste and sediments. Arsenopyrite, Fe-oxides, Fe-root plaque, and As_2 O_3 were the major phases identified.
	Sediment toxicity was measured using 10-day Chironomus dilutes and 21-day Pimephales promelas exposure tests. The toxicity tests found responses ranging of from 100% mortality at the most contaminated site to no statistical difference to the control groups in the least As contaminated site. Toxicity test chamber conditions were directly monitored with dialysis probes (mini-peepers) and Diffusive Gradients in Thin Films (DGTs).
	DGT and mini-peeper deployment in the test beakers allowed for direct correlation of their measurements to trace metal uptake and bioaccumulation during the toxicity tests. Linear regression and ANOVA statistics were used to correlate, when possible, As tissue concentrations in Chironomus dilutes and Pimephales promelas to DGT, mini-peeper and surface water concentration measurements. Statistical analysis was also conducted for Co, Cr, Cu, Ni, Pb, Zn, and Sb though these other metal/metalloids were not always suitable for analysis due to constraints caused by detection limits.
It was found that DGT As was statistically correlated (r2=0.836 and p<0.0005) to uptake in Pimephales promelas but that total element concentrations were also statistically relevant and slightly better at predicting uptake (r2=0.873 and p<0.0005). Mini-peepers could not be analyzed statistically due to challenges in their use within some highly vegetated sediment samples.

abstract: Aboriginal Affairs and Northern Development Canada needs to review the results.

abstract: M.A.Sc.


title: Low-Dose Carbon Monoxide Exposure in Pregnancy; a Potential Therapeutic for Pre-Eclampsia

contributor:
Smith, Graeme N.
Anatomy and Cell Biology

subject:
Heme Oxygenase-1
Pre-Eclampsia
Carbon Monoxide
Human
Mouse
Pregnancy

abstract: Thesis (Ph.D, Anatomy & Cell Biology) -- Queen's University, 2014-05-01 14:38:42.584

abstract:
Preeclampsia (PE) is a maternal disorder of pregnancy, characterized by late-onset hypertension and proteinuria. It affects roughly 5-7% of all pregnancies worldwide and is a leading cause of maternal and fetal/neonatal morbidity and mortality. Cigarette smoking in pregnancy is associated with a 33% reduction in the incidence of PE, and this is dose dependent. It is hypothesized that carbon monoxide (CO), a combustion product in cigarettes, may confer cytoprotective and regulatory properties leading to the decreased incidence of PE. CO is produced endogenously by the enzyme heme oxygenase (HO), and it is thought that the manipulation of the HO/CO system in pregnancy can ameliorate or reduce the pathophysiologic signs of PE.
The exposure of pregnant mice to 250 ppm CO led to an increase in each of the maternal uterine blood flow, vascularity of the placenta and vessel diameter, with a shift towards angiogenesis in the placenta tissue proteins Exposure of human placental villous explants to 250ppm CO led to a decreased production and release of the soluble vascular endothelial growth factor (VEGF) receptor -1 (sFlt-1). This molecule is increased in maternal plasma and placenta tissue of women with PE and it binds with molecules of angiogenesis, limiting their ability to interact with the endothelium. Using an AdsFlt-1 PE-like mouse model, the exposure of mice to 250ppm chronic CO prevented the hypertension, proteinuria and glomerular alterations, supporting the use of CO as a future therapeutic for women with PE.
We completed a pilot study to evaluate the exposure of healthy volunteers to two, one hour inhalations of 250ppm CO. We determined the half-life of CO and we provide baseline kinetics data for males and females following CO inhalation. These data are important for future therapeutic studies in order to better establish proper dosing, concentration of CO and method of delivery.
The results of this thesis contribute to the understanding of the pathophysiology of PE and provide evidence to support the use of CO as a therapeutic for this disorder.

abstract: PhD


title: Chironomid assemblage changes and deformity prevalence in lakes impacted by uranium mining in northern Saskatchewan, Canada

subject:
Paleolimnology
Chironomid
Uranium Mining
Metals

abstract: Uranium mining has the potential to have impacts on surrounding ecosystems, particularly on the aquatic organisms found in lakes near mining activities. The objective of this study was to use paleolimnological techniques to investigate whether changes occurred in chironomid assemblages or the deformities in head capsules increased in two lakes (I-7 and I-9) impacted by increases in potentially toxic elements associated with mining activities at the McClean Uranium mine. Elemental concentrations of U, As, Mo and Se (excluding Se in I-9) have significantly increased both lake sediments since the introduction of the mine in the late 1960s.  Concentrations of Mo differ between Lake I-7 (400 µg g-1) and Lake I-9 (9 ~25 µg g-1) with both increasing several fold following the mine opening. In Lake I-7, Corynocera ambigua and Zalutchia zaluticola decreased from pre-mining to active-mining conditions while Psectrocladius (monospectrocladius) and Polypedilum nubifer increased. Corynocera ambigua dominated the species assemblage (60%) in the pre-mining time period and reduced to minute amounts during active-mining. In Lake I-9, Corynocera ambigua increased slightly in the post-mining time period but there were only minute changes in other taxa between pre-mining and active-mining time periods. Deformities in chironomid head capsules remained low in both lakes and did not change following the initiation of mining actives. There was insufficient literature pertaining to the ability for Corynocera ambigua, Polypedilum nubifer and Psectrocladius (monospectrocladius) to withstand toxic environments except for Polybedilum nubifer which has been previously recorded to demonstrate resistance to the effects of other metals. The stronger change in chironomid assemblage Lake I-7 could have been observed due to the difference in Mo concentration, geographical placement from mining facility and surface area of lake. Multiple stressors could be impacting chironomid assemblage change, including changes in climate. Temperature data of the area showed a probable increase in average annual air temperature between pre-mining and active- mining time periods. More research is needed to attribute changes in chironomid assemblage changes to increases in elemental concentrations, including the need for reference sites away from mining activities.


title: Experimental Response of a Pile in Sand Under Static and Cyclic Lateral Loads

contributor:
Moore, Ian D.
Civil Engineering

subject:
Static and Cyclic Lateral Load
Pile Responses

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2014-05-02 20:29:56.489

abstract:
Piles are engineering structures which are subjected to axial and lateral loading. In this dissertation, pile load tests were performed on a full-scale fabricated pile to understand lateral pile responses under static and cyclic loading. The experiments were performed on a fabricated test pile at the Geo-Engineering Laboratory at Queen's University. Dry loose Olimag Synthetic Olivine sand was used as the test soil.
Instrumentation  including axial strain gauges, null sensors (earth pressure sensors) and string potentiometers were used to monitor pile responses throughout the tests. What differentiates the current study from previous investigations is direct measurements of lateral earth pressure on a test pile using those null sensors with conventional measurements of curvature and deformation. The null sensors of Talesnick (2005) have ‘infinite stiffness’ and calibration that is almost independent of the soil type, soil condition and stress history, qualities that make the sensor superior to other commercially available sensors.
The initial pile response under static loading was examined. Previous laterally loaded pile test programs have utilized curvature measurements to infer moments, and differentiation of moments to determine lateral forces. Comparisons with the directly measured pressures confirmed the effectiveness of differentiated moments. To understand offshore structures, the behaviour of a pile subjected to cyclic loading is examined and explained by elastic soil response at low load levels and the progressive development of inelastic response at higher load levels. In addition, the loading condition (i.e. two-way versus one-way loading) was found to have a substantial effect on pile responses. The pressure distributions for two-way cyclic loading suggest that the lateral pressure is proportional to displacement with peak pressures near the ground surface during elastic responses. The peak lateral pressures move deeper towards the point of rotation with increasing cyclic loads to generate inelastic responses. However, the lateral pressure response is consistently inelastic for one-way loading.

abstract: M.A.Sc.


title: Acidification and Climate Warming: Understanding the Impact of Multiple Anthropogenic Stressors on Adirondack (NY, USA) Lakes

contributor:
Cumming, Brian F.
Biology

subject:
Chrysophytes
Paleolimnology
Acidification
Climate Change
Recovery
Reference Sites
Adirondacks

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2014-05-03 13:17:09.613

abstract: Lakes in the Adirondack Park (NY, USA) are undergoing chemical recovery from acidification. There is now a pressing research need to define recovery targets for acid-impacted sites. Researchers attempting to designate such targets are hampered by two issues: 1) a lack of long-term monitoring data, and 2) the influence of multiple stressors on recovering lakes. This thesis addresses both difficulties by applying paleolimnological techniques within a regional reference lake framework. Using a set of stringent selection criteria, 31 lakes protected from acidification, eutrophication, road salt seepage, and piscivore introductions were identified from 1,469 Adirondack lakes. Ordination techniques showed that the lakes are representative of 24-36% of the chemical/morphological variation of Adirondack lakes. Qualitative and quantitative historic analyses found that many of the lakes experienced early watershed and/or fisheries disturbance, highlighting the danger of assuming that a lake’s condition remains static over time. A top-bottom paleolimnological study revealed that the reference lakes have undergone a ‘shifting baseline’ in species assemblages, with increases in colonial and/or warm-water chrysophyte taxa from pre-1900 to present, changes most likely due to regional warming and/or oligotrophication. A subset of three reference lakes were then paired with two Adirondack lakes that acidified and are undergoing chemical recovery from acidification. The acidified  lakes underwent a significant shift in species composition since the 1995 implementation of the US Acid Rain Program, indicating biological recovery from acidification.  However, both reference and acidified lakes showed increases in colonial chrysophytes since ca. 1970-1980, a trend correlated with mean annual air temperature and ice-cover measures in the two reference lakes. Long-term species changes in acidified/reference lakes suggest that the recovering lakes will not return to their pre-disturbance state but will instead move to a state characterized by an increased abundance of colonial taxa/warm-water species. Overall, this thesis demonstrates the utility of pairing paleolimnological techniques with a regional reference site dataset for tracking shifting baselines and defining recovery targets, a method that could be applied to examine other stressors in other regions, thereby addressing a critical management need.

abstract: PhD


title: Design Specifications for the Development of a Continuous Pelletizing Process for the Production of Spherical, Torrefied Biomass Pellets

contributor:
Strong, David S.
Pollard, Andrew
Mechanical and Materials Engineering

subject:
Torrefaction
Spherical Pellet
Biomass
Pelletization
Q'Pellet

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2014-05-06 14:04:54.059

abstract:
A novel compacted, torrefied, spherical biomass pellet, known as the "Q'Pellet", is
aimed at overcoming the challenges of modern biomass pellets by building on the
bene fits of torrefaction and utilizing the durability of a sphere. Pellets were made
from both untreated hybrid poplar sawdust and material that had been partially
torrefied at 250 C, allowing the torrefaction and pelletizing stages to be decoupled.
A pelletizing die pre-heated to 280 C was successfully used to heat and torrefy room
temperature raw and pre-torrefi ed material, greatly reducing the time required to
produce each pellet.
All Q'Pellets demonstrated 100% mechanical durability, and did not abrade during
a tumbling can test or fracture during an impact resistance (drop) test. The gross
calori fic value (GCV), ash and nitrogen content of pellets produced from raw hybrid
poplar were 21.29+/-0.08 MJ/kg, 2.42+/-0.23 wt%, and <0.01 wt%, respectively.
The GCV, ash and nitrogen content of pellets produced from pre-torre ed material
were 21.25+/-0.34 MJ/kg, 3.58+/-1.11 wt%, and 0.42+/-0.03 wt%, respectively. The
Q'Pellet was compared to biomass fuel speci fications in Europe and North America.
The experiments performed herein provided an understanding of the material and
process properties and limitations. Design speci fications for the development of a
continuous pelletizing process were outlined. BGM Metalworks Inc has been hired by
Queen's University to assist in the design and to fabricate the continuous pelletizing
apparatus.

abstract: Material included in this thesis is subject to intellectual property restrictions, and is the subject of a possible future patent application.  The thesis must be restricted to protect the IP of the researchers.

abstract: M.A.Sc.


title: Digital Control in Microwave Receiver Front-End Components

contributor:
Saavedra, Carlos E.
Electrical and Computer Engineering

subject:
digital control
modulator
self-calibration
mixer

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-05-03 13:16:06.018

abstract:
In this thesis digital control techniques for two receiver front-end components i.e. the downconverter mixer and the modulator are presented. With decrease in size of CMOS-based geometries, decrease in performance and yield of analog components has become an issue. Using the digital components on a System-on-Chip to account for the shortcoming in analog circuitry and thereby developing 'self-calibrating' systems has become a reliable way to address this issue. In the telecommunications industry, this is directly correlated to lower post-fabrication testing times, quicker product development and lower overhead costs.

The first design presented is a 0.13 um CMOS mixer with variable gain capability. A Digital Assist system was put in place to extend the 3-dB bandwidth of the system using a microcontroller. An interpolation routine was used to predict the bias voltages based on variations in frequency and desired input power. The digital-to-analog converter on the  microcontroller was used to set the required bias voltages. The mixer's bandwidth was extended from 12GHz to 15GHz using digital assist. The gain of the mixer with the digital assist in place could be varied from 1.2-9.8dB.

The second design presented is a 5.4GHz multi-scheme modulator fabricated in 0.13 um CMOS technology. The modulator is capable of carrying out quadrature amplitude modulation as well as phase-shift keying modulation. The modulator makes use of a novel OTA design to generate a set of orthogonal basis vectors which allows for facile mapping of the modulated data on the I-Q plane. The modulator  carries out modulation in 4-PSK, 8-PSK, 4-QAM and 16-QAM modes with a maximum error vector magnitude of only 8.51%. A digital assist model to attain ubiquitous operation inside a system is also presented for this modulator.

abstract: M.A.Sc.


title: The examination and characterization of a previously unknown mineral from Alcaparrosa, Chile

subject: Mineral, Alcaparrosa, Chile

abstract: In the summer of 2013 while working with Jennifer Day, Dr. Ron Peterson encountered a mineral with an unknown X-ray diffraction pattern. This mineral is pale yellow in colour, fibrous, very light, with a texture similar to cotton candy. With examination of the mineral in Dr. Peterson’s accommodations at the research site the XRD signature of the mineral changed from unknown to that of copiapite. Peterson attributed this to the difference in relative humidity between the location of the mineral discovery and his accommodations where the relative humidity was higher. At Queen’s, experiments were conducted with the mineral using the FEI Quanta 650 FEG ESEM and Fourier transform infrared spectroscopy (FT-IR) in the Avatar 320 detector, as well as an attempt to determine the relative humidity at which the mineral is stable. Several methods of sample preparation were attempted using the Avatar 320 including a diamond press, DRIFT, and transmission methods with varying degrees of success. The experiments did show that the mineral does react when it is exposed to an increased relative humidity, in the range of 5 to 22.5%, and results in a shift of the structure of the sulfate group as seen through a shift in the peaks  due to sulfur- oxygen bond adsorption detected with the Avatar 320. The FEI Quanta 650 FEG ESEM also showed a significant change in the physical structure of the mineral when exposed to an increased relative humidity that is not observed with the naked eye. The ESEM also allowed for identification of the chemical composition of the mineral whose main components are S, Si, O, and Fe, with smaller amounts of Mg, Al, and K.  The mineral also appears to create sulfuric acid when dissolved in fluids as indicated by respiratory distress of those who handled the mineral at the discovery site. This release of sulfuric acid was noted due the mineral’s light and fibrous characteristics that allowed it to become suspended in the air when disturbed and interact with people in the area. The atomic structure and specific chemical composition of this potentially new mineral is still undetermined.


title: System Identification and Adaptive Control for Grid-Connected Single-Phase AC Inverters

contributor:
Jain, Praveen K.
Electrical and Computer Engineering

subject:
Electrical Engineering
Power Electronics

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-05-05 15:25:47.342

abstract:
This thesis presents adaptive control techniques to improve the stability and performance of grid-tied single-phase inverter systems. There are three main control systems involved in the conversion of DC to AC power: a synchronizer, a current-controller, and a DC-bus controller. The focus of this thesis is to create a control system which responds to the changing operating conditions.
In order to adapt to changing operating conditions, estimations of the variables which influence stability and performance are necessary. A synchronization system is proposed, which delivers very accurate estimation of the grid frequency and voltage amplitude across all operating conditions. The synchronization system also provides an accurate and normalized set of orthogonal vectors for the AC output current reference phase. An adaptive parameter estimation technique is proposed to passively estimate the LCL-filter parameters and DC input current.
Using the parameter estimations of the output filter, an adaptive state-feedback system is proposed. Next, a frequency-adaptive current controller is proposed, which dynamically tunes to the frequency provided by the synchronizer. Finally, the DC-bus controller is enhanced with the grid-voltage estimate and DC current estimator.
The proposed techniques are verified for performance and stability though simulation and experimental results.

abstract: The patents are being applied for based on the material contained in this thesis.

abstract: M.A.Sc.


title: The Genetic Architecture of Life History in Drosophila

contributor:
Chippindale, Adam K.
Biology

subject: Biology Evolution

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2014-05-06 16:01:58.175

abstract:
An organism’s entire life history - the timing of development, reproduction, senescence and death - can depend on the nature of selection for reproductive age. The outcome of selection will depend both on the particular features of the selective environment and on the genetic architecture of life history in the population. The genetic architecture is highly complex and itself variable in response to selection. Various features of the architecture, including available genetic variation, pleiotropy, epistasis, intersexual genetic correlation, mitochondrial genomes and mito-nuclear interactions all play a role in determining the trajectory of life history evolution, and to interact with one another in doing so.
Using eleven laboratory-adapted populations of Drosophila melanogaster that have been subject to controlled long-term selection for differing ages of reproduction, I undertook several experiments that help characterize how these aspects of genetic architecture have contributed to the life history of each population. These experiments combined assays of life history trait values in the standing genetic variation with manipulations of mutation accumulation rate and hybridization, to better understand the nature of selection shaping each life history.
I found surprisingly strong positive pleiotropy between early reproduction and longevity, sufficient to maintain a stable ‘surplus’ life span lasting several weeks post-selection. Selection for extremely early reproduction, on the other hand, induced pleiotropic costs to reproductive traits in each sex in a trade-off with development time. Characterization of the intersexual genetic architecture for life span revealed it was largely sex-limited in nature, consistent with a history of intralocus sexual conflict affecting the trait. There was also evidence, however, that mutations affecting life span might interact to reinforce their effects, and that the resulting costs were manifested in both sexes. Selection on mitochondrial genomes in isolation did not contribute to evolution of age-specific reproduction, but mito-nuclear coadaptation was clearly important to its evolution for males in particular.
Together, these results expand our understanding of how age-specific selection shapes life history in a popular model organism. They can be used to guide future research in this system and allow us to pose important questions to be tested in other species as well.

abstract: PhD


title: Autonomic Workload Management for Database Management Systems

contributor:
Martin, Patrick
Computing

subject:
Workload Management
Autonomic Computing
Database Management Systems

abstract: Thesis (Ph.D, Computing) -- Queen's University, 2014-05-07 13:35:42.858

abstract:
In today’s database server environments, multiple types of workloads, such as on-line transaction processing, business intelligence and administrative utilities, can be present in a system simultaneously. Workloads may have different levels of business importance and distinct performance objectives. When the workloads execute concurrently on a database server, interference may occur and result in the workloads failing to meet the performance objectives and the database server suffering severe performance degradation.
To evaluate and classify the existing workload management systems and techniques, we develop a taxonomy of workload management techniques. The taxonomy categorizes workload management techniques into multiple classes and illustrates a workload management process.
We propose a general framework for autonomic workload management for database management systems (DBMSs) to dynamically monitor and control the flow of the workloads and help DBMSs achieve the performance objectives without human intervention. Our framework consists of multiple workload management techniques and performance monitor functions, and implements the monitor–analyze–plan–execute loop suggested in autonomic computing principles. When a performance issue arises, our framework provides the ability to dynamically detect the issue and to initiate and coordinate the workload management techniques.
To detect severe performance degradation in database systems, we propose the use of indicators. We demonstrate a learning-based approach to identify a set of internal DBMS monitor metrics that best indicate the problem. We illustrate and validate our framework and approaches using a prototype system implemented on top of IBM DB2 Workload Manager. Our prototype system leverages the existing workload management facilities and implements a set of corresponding controllers to adapt to dynamic and mixed workloads while protecting DBMSs against severe performance degradation.

abstract: PhD


title: Log Engineering: Towards Systematic Log Mining to Support the Development of Ultra-large Scale Systems

contributor:
Hassan, Ahmed E.
Computing

subject:
Log Engineering
Software Engineering
Ultra-large Scale System

abstract: Thesis (Ph.D, Computing) -- Queen's University, 2014-05-08 12:56:23.319

abstract:
Much of the research in software engineering focuses on understanding the dynamic nature of software systems. Such research typically uses automated instrumentation or profiling techniques on the code. In this thesis, we examine logs as another source of dynamic information. Such information is generated from statements inserted into the code during development to draw the attention of system operators and developers to important run-time events. Such statements reflect the rich experience of system experts. The rich content of logs has led to a new market for log management applications that assist in storing, querying and analyzing logs. Moreover, recent research has demonstrated the importance of logs in understanding and improving software systems. However, developers often treat logs as textual data. We believe that logs have much more potential in assisting developers. Therefore, in this thesis, we propose Log Engineering to systematically leverage logs in order to support the development of ultra-large scale systems.
To motivate this thesis, we first conduct a literature review on the state-of-the-art of software log mining. We find that logging statements and logs from the development environment are rarely leveraged by prior research. Further, current practices of software log mining tend to be ad hoc and do not scale well.
To better understand the current practice of leveraging logs, we study the challenge of understanding logs and study the evolution of logs. We find that knowledge derived from development repositories, such as issue reports, can assist in understanding logs. We also find that logs co-evolve with the code, and that changes to logs are often made without considering the needs of Log Processing Apps that surround the software system. These findings highlight the need for better documentation and tracking approaches for logs.
We then propose log mining approaches to assist the development of systems. We first find that logging characteristics provide strong indicators of defect-prone source code files. Hence, code quality improvement efforts should focus on the code with large amounts of logging statements or their churn. Finally, we present a log mining approach to assist in verifying the deployment of Big Data Analytics applications.

abstract: PhD


title: Sagacious Liminality: The Boundaries of Wisdom in Old English and Old Norse-Icelandic Literature

contributor:
Straker, Scott-Morgan
English

subject:
Monsters
Old English
Króka-Refs Saga
Volsunga Saga
Old Norse-Icelandic
Beowulf
The Wanderer
Liminality
Order of the World
Vainglory
Proverbs
Old English Daniel
Sólarljóð
Folklore
Gesta Danorum
Hervarar saga ok Heiðreks
Wisdom
Maxims I and II
Málsháttakvæði
Riddles

abstract: Thesis (Ph.D, English) -- Queen's University, 2014-05-08 15:35:46.885

abstract: This dissertation examines the relationship between wisdom and identity in Old English and Old Norse-Icelandic literature. At present, the study of medieval wisdom is largely tangential to the study of proverbs and maxims. This dissertation makes wisdom its primary object of study; it sees wisdom not just as a literary category, but also as a cultural discourse found in texts not usually included in the wisdom canon. I therefore examine both wisdom literature and wisdom in literature. The central characteristic of wisdom, I argue, is its liminality. The biblical question “Where is wisdom to be found?” is difficult to answer because of wisdom’s in-between-ness: it is ever between individuals, communities, and times (Job 28:12 Douay-Rheims). As a liminal discourse, wisdom both grounds and problematizes identity in Old English and Old Norse-Icelandic literature. After a preliminary chapter that defines key terms such as “wisdom” and “wisdom literature,” I examine heroic wisdom in three characters who are defined by their wise traits and skills and yet who are ultimately betrayed by wisdom to death or exile. The implications of this problematic relation to wisdom are then examined in the next chapter, which analyzes the composition of wisdom in proverb poems. Like the wise hero, the poets represented in these poems blend their own voices with the voice of community, demonstrating that identity is open and therefore in need of constant revision. Next I examine how the liminality of wisdom is embodied in the figure of the wise monster, who negatively marks the boundaries of society and its desires. This then leads to a study of the reception of wisdom in chapter six, which focuses on instruction poems. Like narratives of wise monsters, these texts present lore as the nostalgic remnant of a tradition that defines identity, in this case the identity of a community. However, nostalgia assumes loss, and these texts also reveal an underlying fear that wisdom, the basis of the community’s identity, will be forgotten. Whether communal or individual, identity in this literature is both formed and threatened by liminal wisdom.

abstract: I desire the thesis to be restricted for future publication purposes.

abstract: PhD


title: Multimode Devices in Communication and Sensing Systems

contributor:
Yam, Scott
Electrical and Computer Engineering

subject:
Mode Converter
Theoretical Model
Mach-Zehnder Interferometer
Fiber Bragg Grating
Fiber Taper
Refractive Index
Optic Sensor
Experiment Implementation

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-05-09 11:44:44.837

abstract:
Multimode devices play an increasingly important role in both communication and sensing systems. Mode division multiplexing (MDM) in multimode fiber (MMF) is becoming a promising method to further increase the capacity of optical transmission link with a controllable mode coupler. Similarly, optic sensors based on core-cladding-mode interference can be widely used in measurement of refractive index (RI), temperature and strain.
Fiber Bragg gratings (FBGs) in single mode operation have been extensively studied as in-line optical components for both communication and sensing applications. In recent years, research has been extended to FBGs in few-mode operation as mode couplers in MDM applications. Experimentally, mode conversion from fundamental linear polarization (LP) mode LP01 to higher order LP11 mode in two-mode FBG (TMFBG) has been observed. Index asymmetry and electric field distortion induced by ultraviolet (UV) side illumination in fabrication of FBG make the two modes no longer orthogonal. However, its spectrum analysis mainly depends on experimental data and software simulation using the complex finite element method (FEM). Here a simpler theoretical model based on coupled mode theory (CMT) and Runge-Kutta method (RKM) is proposed. An analytical expression of the mode coupling coefficient is derived and the modeling results match very well with experimental data.
 Abrupt fiber tapers allow power transfer between core and cladding modes and show promise as RI sensing components when two abrupt tapers are cascaded into an in-line Mach-Zehnder interferometer (MZI). The main advantage of the MZI taper sensor is its low manufacturing cost. However, the optical spectrum analyzer (OSA) used as the receiver and demodulation device in the conventional setup is still expensive. Three simplified schemes of fiber taper MZI RI sensor systems are designed and demonstrated experimentally. The transmitter and the demodulation devices for the three schemes are a single wavelength laser and a photodetector (PD), two modulated lasers and a PD together with data acquisition and processing module, and a broadband source (BBS) and a PD together with matched MZI, respectively. In all those implementations OSA is not required, which significantly lowers the cost and leads to easy integration. Although extra modulation/demodulation devices are required, the second implementation has the best performance. Automatic operation is realized by LabVIEW programming. High sensitivity (2371 mV/RI unit (RIU)) and high stability are achieved experimentally. Those new schemes have great potential to be applied to other interferometric optic sensor systems.

abstract: The research results in the thesis have not been published yet. We need some time to get our journal papers prepared. We do not want our novel ideas be available to everyone before that.

abstract: M.A.Sc.


title: Terahertz driven intraband dynamics of excitons in nanorods

subject: excitons Intraband nonlinear Terahertz nanorods CdSe

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2014-05-14 23:37:58.604

abstract: Quantum dots and nanorods are becoming increasingly important structures due to their potential applications that range from photovoltaic devices to medicine. The majority of the research on carrier dynamics in these structures has been in the optical regime, with little work performed at Terahertz frequencies where excitonic dynamics can be more directly probed. In this work, we examine theoretically the interaction of Terahertz radiation with colloidal CdSe nanorods to determine the dynamics of excitons generated via a short optical pulse. We calculate the energies and wavefunctions for the excitons within the envelope function approximation in the low density limit where there is at most one exciton per nanorod. The linear Terahertz transmittance and absorbance is found for nanorods that are approximately 70 nm in length and 7 nm in diameter and are compared with experimental results that have shown the first observation of intra-excitonic transitions in nanorods. We find absorbance peaks at 8.5 THz and 11 THz that result from polarizations in the longitudinal (rod axis) and transverse directions respectively. Our theoretical results show that the 8.5 THz and 11 Thz peaks are due to 1s-2pz and 1s-2px transitions respectively. The theoretical absorbance spectra is in good agreement with the experimental one and show that only the ground state is significantly populated 1 ps after optical excitation. This provides strong evidence of rapid trapping of excited holes into the ligand used to passivate the nanorods. A full set of dynamical equations were then constructed from Heisenberg's equation of motion, and were used to model the excitonic correlations as a function of time. Transmittance and absorbance were calculated for different nanorod orientations and electric field strengths in both the linear and nonlinear regime. These results were then averaged over nanorod orientation in order to more accurately reflect experimental conditions. Nonlinearity was found to become significant at peak pulse field strengths of 7 kV/cm and greater. Due to two-photon processes, we predict the 2pz-3dz transition that is not observed in the linear regime will be clearly seen in the nonlinear absorbance spectrum.

abstract: M.Sc.


title: Artificial Neural Networks for Fault Detection and Identification on an Automated Assembly Machine

contributor:
Surgenor, Brian W.
Mechanical and Materials Engineering

subject:
Artificial neural networks
Fault identification
Fault detection

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2014-05-16 17:21:13.676

abstract:
Artificial neural networks (ANNs) have been used in many fault detection and identification (FDI) applications due to their pattern recognition abilities. In this study, two ANNs, a supervised network based on Backpropagation (BP) learning and an unsupervised network based on Adaptive Resonance Theory (ART-2A), were tested for FDI on an automated assembly machine and compared to a conventional rule-based method. Three greyscale sensors and two redundant limit switches were used as cost-effective sensors to monitor the machine's operating condition.

To test each method, sensor data were collected while the machine operated under normal conditions, as well as 10 fault conditions. Features were selected from the raw sensor data to create data sets for training and testing. The performance of the methods was evaluated with respect to their ability to detect and identify known, unknown and multiple faults. Their modelling and computational requirements were also considered as performance measures.

Results showed that all three methods were able to achieve perfect classification with the test data sets; however, the BP method could not classify unknown or multiple faults. In all cases, the performance depended on careful tuning of each method’s parameters. The BP method required an ideal number of neurons in the hidden layer and good initialization. The ART-2A method required tuning of its classification parameter. The rule-based method required tuning of its thresholds. Although it was found that the rule-based system required more effort to set up, it was judged to be more useful when unknown or multiple faults were present. The ART-2A network created new outputs for these conditions, but it could not give any more information as to what the new fault was. By contrast, the rule-based method was able to generate symptoms that clearly identified the unknown and multiple fault conditions. Thus, the rule-based method was judged to be the best overall method for this type of application.

It is recommended that future work examine the application of computer vision-based techniques to FDI with the assembly machine. The results from this study, using cost-effective sensors, could then be used as a performance benchmark for image-based sensors.

abstract: M.A.Sc.


title: Hydroclimatic and Landscape Controls Over Mudboil Formation in the Canadian High Arctic

contributor:
Lamoureux, Scott F.
Geography

subject:
Disturbance
Arctic
Subsurface Pressurization
Mudboil
Permafrost

abstract: Thesis (Master, Geography) -- Queen's University, 2014-05-22 13:56:49.078

abstract: This study aimed to gain an understanding of changing active layer dynamics in the High Arctic, specifically in terms of understanding the spatial distribution of mudboils to identify climatic and landscape controls, and active layer processes driving their formation. Systematic mapping of mudboils and sediment and water sampling was undertaken at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, Nunavut in 2012 and 2013. Based on borehole stratigraphic profiles taken at CBAWO, three primary soil units were determined: mudboils at surface; overburden (soil) material; and a grey, fine-grained layer at approximately 80cm depth. These soil classes were used for comparison to gain an understanding of the properties and origins of the mudboil materials. Results indicate that these features only occur late in the melt season during exceptionally warm years (2007, 2011, and 2012) and in some cases closely follow major rainfall events. High-resolution satellite imagery was analyzed to determine landscape controls over mudboil formation. Notably, mudboils were significantly associated with bare soil and polar semi-desert vegetation settings, corresponding to increased active layer depth and rate of thaw when compared to more vegetated areas. Further, localized occurrence of mudboils appears to be related to differential soil moisture retention and spatially heterogeneous soil water pressurization due to thaw into the ice-rich transient layer in warm years. We hypothesize that the locally drier locations develop soil ped structures that contribute to diapir development and mud ejection when seasonal melt and hydraulic conditions pressurize soil water. Geotechnical and geochemical analysis of soil samples indicates that mudboils at surface do not significantly differ in terms of composition and physical properties from the undisturbed overburden material. This is consistent with a fine-grained slurry likely being generated in situ from a parent bed and subsequently ejected to surface. This research provides insights into the processes and landscape controls over mudboil formation to aid in understanding localized soil water response to deep summer thaw, with implications for surface water quality and predictions and potential mitigation of permafrost-related degradation and disturbance.

abstract: M.Sc.


title: Perceived General Health vs. Objective Physiological Health Among Senior Women of Kingston: Identifying the Overestimators

contributor:
Moore, Spencer
Kinesiology and Health Studies

subject:
Cognitive Process
Metabolic Syndrome
Self-reported Health

abstract: Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2014-05-21 00:14:26.427

abstract:
Self-reported health (SRH) tends to decline slower as people age compared to the decline of their objective health. If individuals believe they are in good health but actually are in poor health, their perceived susceptibility to disease may be low. Consequently, those individuals may feel less compelled to improve their health, which would make them a higher risk population. This project aims to examine the association of SRH and Metabolic Syndrome (MetS) in senior women, and whether personal and interpersonal dimensions help explain the degree to which SRH corresponds with MetS.
Data are from the Kingston Senior Women Study (KSWS, n=100, 65 years of age and older). KSWS participants completed a questionnaire on their social background, psychosocial conditions, health behaviours, and SRH. Participants also provided physiological measures and medical information, so that MetS could be assessed, following the harmonized definition. MetS is a cluster of at least three of the following criteria: obesity, elevated blood pressure, low level of HDL cholesterol, raised triglycerides, and fasting plasma glucose. Two categories represented the correspondence between SRH and MetS: those who have a congruent perception of their health and those who overestimated it.
Greater physical activity was associated with higher SRH (OR: 1.10; 95%CI: 1.01 – 1.20) and lower odds of MetS (OR: 0.64, 95%CI: 0.47 – 0.88) among the participants. However, only social network size was associated with lower odds of health overestimation (OR: 0.46, 95%CI: 0.26 – 0.80).
Larger social networks may give access older women to a greater source of information about their own health, leading possibly to more accurate assessments of health. Such information can be conveyed as feedback from close ties. This information can also be conveyed as a more accurate perception of the health of their reference group when self-assessing their own health. Findings of this study may help identify women who are at greater risk of cardiovascular disease but who may be less likely to participate in health promotion programs.

abstract: M.Sc.


title: Studying the Impact of Developer Communication on the Quality and Evolution of a Software System

subject:
Communication
Software Evolution
Unstructured Data
Software Engineering
Software Quality
Empirical Studies

abstract: Thesis (Ph.D, Computing) -- Queen's University, 2014-05-22 12:07:13.823

abstract:
Software development is a largely collaborative effort, of which the actual encoding of program logic in source code is a relatively small part. Software developers have to collaborate effectively and communicate with their peers in order to avoid coordination problems. To date, little is known how developer communication during software development activities impacts the quality and evolution of a software.
In this thesis, we present and evaluate tools and techniques to recover communication data from traces of the software development activities. With this data, we study the impact of developer communication on the quality and evolution of the software through an in-depth investigation of the role of developer communication during software development activities. Through multiple case-studies on a broad spectrum of open-source software projects, we find that communication between developers stands in a direct relationship to the quality of the software. Our findings demonstrate that our models based on developer communication explain software defects as well as state-of-the art models that are based on technical information such as code and process metrics, and that social information metrics are orthogonal to these traditional metrics, leading to a more complete and integrated view on software defects. In addition, we find that communication between developers plays a important role in maintaining a healthy contribution management process, which is one of the key factors to the successful evolution of the software. Source code contributors who are part of the community surrounding open-source projects are available for limited times, and long communication times can lead to the loss of valuable contributions.
Our thesis illustrates that software development is an intricate and complex process that is strongly influenced by the social interactions between the stakeholders involved in the development activities. A traditional view based solely on technical aspects of software development such as source code size and complexity, while valuable, limits our understanding of software development activities. The research presented in this thesis consists of a first step towards gaining a more holistic view on software development activities.

abstract: PhD