title: Risk Assessment of Arsenic in Arabic Area Rice Using On-Line Leaching and Speciation Analysis by Ion Exchange Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometry

contributor:
Beauchemin, Diane
Chemistry

subject:
Analytical Chemistry
Chemistry

abstract: Thesis (Master, Chemistry) -- Queen's University, 2014-10-23 12:09:46.012

abstract:
For the first time, a simple on-line continuous leaching method, where artificial gastrointestinal fluids are sequentially pumped through a mini-column of food while As is continuously monitored by inductively coupled plasma mass spectrometry (ICP-MS), is used to assess the bio-accessibility of As in Arabic area rice. This on-line leaching method offers several advantages over batch methods; most notably, it provides real-time leaching data and involves a shorter and simpler sample preparation, which reduces the risk of contamination. There was no significant difference between the bio-accessible As concentrations measured by on-line and batch methods, although, with the on-line method, the concentration sum of As leached and As left in the residue was closer to the total As concentration according to a Student’s t-test at the 95 % confidence level, which is commensurate with the batch method being more subject to contamination.  Leaching with artificial saliva released As the most, followed by artificial gastric juice and intestinal fluid. Both the on-line and batch methods showed that 20%-95% of As in rice samples is bio-accessible. The results of As bio-accessibility in unwashed raw rice and in washed cooked rice after simply washing the rice with water prior to cooking were similar, indicating that cooking had no significant effect on As bio-accessibility.

A method based on anion-exchange chromatography with on-line detection by ICP-MS was also used for the speciation analysis of As. For better risk assessment, speciation analysis was performed on washed and cooked samples. Because saliva leached the most As, the determination of As species was only conducted in saliva leachates. The results revealed that the concentration of inorganic As species in rice varies to some extent according to the samples' location. In general, As(V) predominated over As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA).  Although As(V) is considered to be more toxic than MMA and DMA, this investigation indicates that the concentration of As(V) can be reduced significantly by washing rice several times, thereby decreasing the risk of arsenic poisoning.

abstract: M.Sc.


title: On The Link Between Mobile App Quality And User Reviews

contributor:
Hassan, Ahmed E.
Computing

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

subject: software app iOS Android Mobile reviews

abstract: Thesis (Master, Computing) -- Queen's University, 2014-10-23 20:38:53.919

abstract:
Mobile app stores contain millions of apps which users can download and install on their smart phones. Each app has a page in the mobile app store that includes app's description, a download link for the app, and a space for users to review the app. Each review has a 1-5 star rating and a review-comment. Unlike desktop and server side-software where direct user feedback about software quality was difficult to acquire, app developers now have access to the user's perspective of their apps via the reviews. Since apps with high-rating reviews are downloaded statistically significantly more than apps with low-rating reviews, the insights from studying these reviews are very important. Thus in this thesis, we analyze hundreds of thousands of reviews of Android and iOS apps to help developers understand the relationship between app quality, and the feedback in reviews.

In this thesis, we find that low-rated reviews of apps contain 12 different complaint types which have varying impact and frequencies. The most frequent complaints are about functional errors, feature requests, and app crashes; complaints about privacy, ethical and hidden cost issues receive the worst star ratings. For Android developers struggling with device fragmentation, we find that different Android devices give varying star ratings. However, we show that device info from reviews can also be used to identify a subset of Android devices that should be prioritized for testing. Finally, we show that warnings from FindBugs, a static analysis tool, are related to lower average app ratings and the complaints that users leave in the reviews. This thesis shows how studying the reviews of mobile apps can help developers prioritize their testing efforts to address the concerns of their users.

abstract: M.Sc.


title: FRAP Measurements of Solute Diffusion Through Hydrogels

contributor:
Amsden, Brian
Chemical Engineering

subject:
FRAP
Solute Diffusion
Hydrogels

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2014-10-30 22:25:00.854

abstract:
The distribution of therapeutic agents such as proteins or drug-loaded nanoparticles within a hydrogel following release influences their rate of absorption at the desired site of action. For formulation design purposes, it is, therefore, important to be able to predict their diffusivity within vehicles like the hydrogel. For this purpose, the diffusivity of solute probes within a hydrogel can be estimated using a mathematical expression based on describing the diffusion of spheres within a macromolecular matrix.
The assumptions of the obstruction-scaling model were assessed using fluorescence recovery after photobleaching. The obstruction model demonstrated excellent predictive capabilities for solute diffusion in polymer solutions using different molecular agents as shown through the work of Zhang and Amsden. To extend its applicability to hydrogels, the assumption must be valid that the correlation length of a hydrogel is the same as that of a polymer solution at equivalent concentrations. The results in this study confirm the validity of this assumption by comparing the predictions of the obstruction model to diffusion measurements of FITC-dextran (4, 10, 20, 40 kDa) in alginate-methacrylate gels. The model provided good predictions for small diffusing agents (4, 10 kDa) and underestimated the diffusion coefficients of dextrans exceeding 20 kDa. This difference was attributed to reptation effects that become more influential as the solute radius approaches the correlation length of a network.

abstract: M.A.Sc.


title: Reconsidering Gender in the Multi-level Governance of Land in East Africa: Governing the “Global Land Grab”?

contributor:
Little, Margaret
Political Studies

subject: Gender

subject: Africa

subject: International Development

subject: Tanzania

subject: Land

subject: Global Governance

subject: Agriculture

subject: Land Grab

subject: International Relations

subject: Customary Tenure

subject: International Political Economy

subject: World Bank

subject: FAO

subject: Feminist International Relations

subject: Women

subject: Food Security

subject: Political Science

abstract: Thesis (Ph.D, Political Studies) -- Queen's University, 2014-10-27 10:56:35.976

abstract:
In the twenty-first century, there is a global rush for agricultural land. This rush is extremely profitable and extremely destabilizing, nowhere more so than in low-income countries with large reserves of arable agricultural land. Recent years have witnessed the emergence of global governance initiatives aimed at ameliorating the negative effects of large-scale commercial agricultural acquisitions. But low-income countries seeking to reform land governance have encountered serious obstacles.
Tanzania is just such a case. For years, rural populations and feminist groups have been crying foul over forced displacement, corrupt land dealing, and the marginalization of women. Yet Tanzania has long been praised for its progressive efforts to recognize customary land tenure and promote gender equality in both land rights and participation in land governance. From the outside, one might think that Tanzania has successfully balanced global agricultural investment with local practices. But this is not necessarily the case. Why haven’t these Tanzanian measures been able to prevent unjust outcomes?
This dissertation assesses global land governance initiatives with reference to Tanzania’s struggles to implement land governance reform. It argues that the road to land reform is complicated by oversimplified assumptions about gender in the governance of land. To develop this argument, this dissertation analyzes two prominent global land initiatives: the Principles for Responsible Agricultural Investment (PRAI) and the Voluntary Guidelines on the Responsible Governance of Land Tenure. By employing a gender-sensitive global governance framework, this dissertation expands the scholarly definition of governance by considering practices ordinarily excluded from traditional analysis. These include family and community forms of governance, which have a profound effect on the way global- and national-level policies are enacted. In doing so, this analysis illustrates obstacles to land reform, the limits of liberal rights-based frameworks, and the folly of considering land deals as a strictly global-level and gender-neutral process. Indeed, the global land deal is revealed to be at once local and global, embedded in a complex of socio-political gendered relationships.

abstract: I will be looking to publish my thesis as a book, and under the advice of my supervisor and an editor at a university press, I will be restricting it.

abstract: PhD


title: Evolutionary Ecology of Range Limits: Conceptual Syntheses and Empirical Tests

contributor:
Eckert, Christopher G.
Biology

subject: Biogeography Evolution Ecology

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2014-10-27 19:17:37.767

abstract: Understanding the environmental, demographic, and evolutionary processes underlying species’ range limits (RLs) is a primary goal of ecology, and increasingly important for conservation in a world of changing species distributions. This thesis addresses three of the most pressing questions: whether RLs typically reflect niche or dispersal constraints; whether generalizations regarding the limiting niche constraints are possible; and how the processes underlying current RLs might affect future RLs. First, I conducted a meta-analysis of transplant experiments beyond species’ ranges, which can directly test the first questions. Performance declined beyond the range for 75% of 111 tests, confirming the broad importance of underlying niche constraints. Results supported the long-proposed but seldom-tested hypothesis that biotic interactions are especially important at low-elevation/equatorial RLs. However, dispersal caused frequent (ca. 50%) mismatches between range and niche limits, often constraining geographic distributions, while extending elevational RLs. Second, I construct a theoretical framework exploring how selection on dispersal varies across species ranges, and how this affects current and future RLs. Whereas dispersal should always increase along invasion fronts, its evolution is likely constrained during expansion of native species, and may play a decisive role in maintaining genetic diversity at RLs contracting due to climate change. Local adaptation to a shifting environmental gradient could select for increased dispersal throughout the range, including contracting limits. Third, I test the importance of niche vs. dispersal constraints and the demographic, environmental and evolutionary patterns underlying the elevational RLs of the annual herb Rhinanthus minor L. Multi-generation demographic surveys of natural populations spanning four range-wide transects reveal that population productivity (net reproductive rate NRR and seed production/m2) declined toward both limits, reflecting low reproductive success at high elevations, but early life-stage failure at low elevations. Surveys suggested an increasing role of competition, but not herbivory, toward the lower RL. A 3-yr reciprocal transplant experiment confirmed that strong niche constraints underlie R. minor’s RLs, as all sources failed beyond both limits (NRR<1). Seed quality declined at upper RLs, but local adaptation in phenology enabled early-flowering high-elevation sources to reproduce in short growing seasons, making them the best poised to expand the upper RL.

abstract: PhD


title: The role of the epithelial-mesenchymal transition in aggressive tumour phenotypes

contributor:
Feilotter, Harriet
Park, Paul
Pathology and Molecular Medicine

subject:
Metastasis
Chemoresistance
Biomarkers
Ovarian Cancer
Prostate Cancer
EMT

abstract: Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2014-10-28 12:57:49.336

abstract:
The epithelial-mesenchymal transition (EMT) is an evolutionarily conserved developmental process characterized by the loss of intercellular contacts, changes in cell polarity and increased migration and invasion. EMT has recently been shown to have a significant impact on chemotherapy response and metastatic progression in cancer cells. We hypothesized that because EMT contributes to aggressive cancer phenotypes, expression profiles of key EMT modulators could be profiled in ovarian and prostate tumours to distinguish aggressive from non-aggressive disease.
	Our results demonstrated that increased EMT gene expression was correlated with chemotherapy resistance in ovarian cancer, and with higher Gleason pattern in prostate cancer, confirming an association between EMT and increased risk for cancer progression.  This underscores the potential for EMT gene signatures to be used as clinically relevant predictive and prognostic biomarkers.
	Functional studies using in vitro models of Cisplatin-resistant ovarian cancer and invasive prostate cancer demonstrated that inhibition of EMT signaling, both through the dysregulation of key transcription factors (SNAI1, SNAI2, ZEB1), and repressed expression of phenotypically important genes such as VIM, SPARC, CLTC and HIF1A resulted in loss of aggressive attributes in these cell lines.  This included re-sensitization of our ovarian cancer cells to the effects of Cisplatin, while significantly reducing cell migration and invasion in our prostate cancer cells, both in 2- and 3-dimensional culture models.
	Furthermore, using our prostate cancer knockdown cell lines, we were able to assess gene expression changes in response to single gene repression. As a result, those genes that appear to have the highest degree of connectivity within the context of our EMT network were identified, thus contributing to the overall understanding of EMT regulation.
	Ultimately, we have been able to assess the role of the epithelial-mesenchymal transition in aggressive tumour behaviours, such as resistance to chemotherapy and progression towards metastatic events. The results of this work indicate that gene expression signatures associated with EMT may be useful as predictive and prognostic biomarkers in various cancer types. Furthermore, gene knockdown studies have provided insight into EMT signaling network regulation, as well as the functional contribution of a number of genes to alterations in migratory and invasive cancer cell programs.

abstract: PhD


title: Large-Scale Horizontal Coherent Structures in a Deep Open Channel Flow: an Experimental Study

contributor:
da Silva, Ana Maria Ferreira
Civil Engineering

subject: River Flows

subject: Continuous Wavelet Transform

subject: Open-Channel

abstract: Thesis (Ph.D, Civil Engineering) -- Queen's University, 2014-10-29 16:55:13.301

abstract:
This work is a study of the size, dynamics and morphological consequences of large-scale horizontal coherent structures (HCS's) in a deep open-channel flow. The study has the following three objectives: 1- to assert the existence of HCS's in a deep open-channel flow and establish their characteristic times and lengths; 2- to penetrate the dynamics of the life cycle of HCS's in such a flow; and 3- to gain insight into why the bed forms known as alternate bars disappear in such flows, even though meandering can still occur. The study is intended as an extension of previous work carried out at Queen's University and focusing on a shallow, alternate bar inducing flow.
For the present purposes, six series of flow velocity measurements were carried out in a 21 m long, 1 m wide straight channel, conveying a 0.14 m deep flow. The bed surface consisted of a silica sand having an average grain size of 2 mm; its surface was flat. The bed slope was such that the bed shear stress was substantially below the threshold for the initiation of motion. The measurements were carried out with the aid of 16 MHz 2D Son Tek Micro-ADV's.
The presence of HCS's affecting (or occupying) the entire body of fluid was unambiguously revealed by the present measurements. The average horizontal burst length and period of the measured flow were found to be equal to 5.5 m. The results of a quadrant analysis of the joint behaviour of the longitudinal and transversal components of fluctuating velocity, and the analysis of the plan distribution of planar Reynolds shear stress show that these structures originate at the upper layers of the flow.
This study further demonstrates that some form of upstream discontinuity is able to regularize the plan configuration of the HCS's, so as induce the internal meandering of the flow. The HCS's were found to be of a rather diffuse nature towards the lower layers of flow, which likely explains why they are not able to produce alternate bars.

abstract: I am waiting for my publications.

abstract: PhD


title: Short- and Long-Term Performance of Compressed Earth Blocks and Sandwich Panels with Natural Skins

contributor:
MacDougall, Colin
Fam, Amir Z.
Civil Engineering

subject:
Environmental aging
Plasticure
Compressed earth blocks
Epoxidized pine oil
Flax fibres
Freeze-thaw
Fibre-reinforced polymer
Sandwich panel
Durability

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2014-10-30 17:20:33.901

abstract:
A drastic increase in environmental awareness has increased demand for renewable materials, energy efficient design and low embodied energy. Two technologies that purport to address this demand are Compressed Earth Blocks (CEB) and Structural Insulated Panels (SIP).
CEBs, a form of earthen masonry, can be a cost-effective, locally produced material that provides high thermal capacity with low environmental impact. There is increasing interest in using the blocks in cold climates. However, CEBs are limited by manufacturing controls and susceptibility to water damage. In this study, various combinations of cement and lime stabilizers were tested with metakaolin, a pozzolan, and Plasticure, a water repellent, to determine the compressive strength when CEBs are dry and fully saturated at unconditioned and freeze-thaw conditioned states. Results showed that the most beneficial additive for improving wet-state capacity was Plasticure. Blocks manufactured with 10% cement and Plasticure yielded the best performance, with a dry unconfined strength of 10.23±0.81 MPa and an 11.6% reduction in strength when wet. When exposed to freeze-thaw cycling, Plasticure reduced variability in strength reduction from 90.9% to 23.5%, and increased strength retention by up to 74.7%.
SIPs are becoming increasingly popular because of their light weight, ease and speed of installation, and high thermal insulation capabilities; however, conventional systems are unsustainable due to their reliance on synthetic fibres and petroleum-based resins. This study focused on the short- and long-term performances of Flax Fibre Reinforced Polymer (Flax-FRP) and compared it to Glass-FRP. Then it assessed the replacement of conventional Glass-FRP skins with skins made of Flax-FRP and a resin blend containing epoxidized pine oil. Results showed that Flax-FRP had a tensile strength and modulus of one third the values of Glass-FRP. Using the Arrhenius relationship, it was estimated that Flax-FRP would retain 60% of its tensile strength after 100 years of saltwater exposure at an annual mean temperature of 10°C. Sandwich panels with three layers of flax fibres provided equivalent strength and stiffness, but better deformability, than panels with one layer of glass fibres. Epoxidized pine oil-based skins decreased strength by up to 23% compared to epoxy-based skins.

abstract: M.A.Sc.


title: Browser Fingerprinting: Analysis, Detection, and Prevention at Runtime

contributor:
Zulkernine, Mohammad
Computing

subject:
Fingerprinting
Web Privacy
Detection
Prevention
Runtime

abstract: Thesis (Master, Computing) -- Queen's University, 2014-10-31 11:02:53.485

abstract:
Most Web users are unaware of being identified or followed by web agents which leverage techniques such as browser fingerprinting (or fingerprinting). Data obtained through such fingerprinting techniques can be utilized for various purposes ranging from understanding the types and properties of the user's browser to learning the user Web experience (e.g., through the browsing history). For enterprises, this can be a useful means to personalize services for their end-users or prevent online fraudulent activities. Similarly, a good fingerprinting technique can provide a rich set of data for various adversary purposes such as for compromising the security and privacy of Web users.
Careful or attentive Web users might configure privacy enhancing tools (e.g., pop-up and cookie blockers) or operate in the private mode of the browser in order to block or prevent fingerprinters. However, recently we have observed that new fingerprinting methods can easily bypass the existing fingerprinting detection and prevention mechanisms. Moreover, while the topic of browser fingerprinting has been well studied, little attention was given to their detection and prevention.
To address this challenge, we first analyze and reverse engineer the most widely used fingerprinting methods on the Web and unify these methods for developing a hybrid fingerprinting tool, called Fybrid. Furthermore, we integrate Fybrid with a social networking service and develop an integrated Web application, called iFybrid. Using iFybrid, we show the possibility of performing individual identification on top of browser identification using fingerprinting. We also identify metrics related to each method which are the indicators for performing fingerprinting attempts. Then, we use the identified metrics and propose a novel runtime fingerprinting detection and prevention approach, called FPGuard. FPGuard monitors activities of the running websites on the user's browser. While the detection capability of FPGuard is evaluated using the top 10,000 Alexa websites, its prevention mechanism is evaluated against four fingerprinting providers. Our evaluation results show that FPGuard can effectively detect and mitigate fingerprinting at runtime without interfering the user's browsing experience.

abstract: M.Sc.


title: Efficient Network Coding for Different Network Topologies

contributor:
Blostein, Steven D.
Chan, Wai-Yip Geoffrey
Electrical and Computer Engineering

subject: Network Coding

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2014-10-31 11:54:55.406

abstract:
Network coding is known to be able to improve a network's throughput and resilience to packet losses. However, in practice high decoding complexity has been a major obstacle that prevents network coding from being widely employed. This thesis considers efficient network coding methods that have low complexity for different types of scenarios. Simple network topologies are first considered. We propose a systematic network coding approach for networks that consist of one or two two-hop lossy paths. It is proved that, compared to the random linear network coding approach, the proposed scheme requires much less computation in encoding and decoding and also achieves a higher end-to-end rate. It is demonstrated that a judicious use of uncoded packets in these networks may provide considerable gain over random coding.

For networks with complex or changing topologies, we investigate the generation-based strategy to design network codes, in which source packets are grouped into subsets called generations and coding is only performed among packets belonging to the same generation. We design generation-based network codes for two different decoders that may be used in different scenarios to meet specific performance/complexity constraints. The first approach, which is generation-by-generation decoding, decodes within generations and therefore its complexity can be made linear by properly choosing the generation size. We analyze the decoding process and propose 1) a method to estimate the optimal amount of overlap among generations, which is a key parameter of generation-based network codes and 2) a new code based on unequal-size generations. The proposed code is shown to outperform existing codes in terms of both computational cost and reception overhead. The second approach considers overhead-optimized decoding, which decodes generations jointly and has lower overhead than the generation-by-generation decoder but requires more computation. We provide an overhead-optimized decoder design with low computational cost and then design codes that are sparser than existing codes. The proposed code is shown to have lower overhead and decoding cost.

abstract: PhD


title: Leaving Home, Teaching Abroad, Coming Home: a Narrative Journey of International Teaching

contributor:
Luce-Kapler, Rebecca
Education

subject:
International Schools
International Education
Canadian Teachers
Narrative
Teacher Identity

abstract: Thesis (Ph.D, Education) -- Queen's University, 2014-10-31 14:31:31.366

abstract:
This dissertation tells a research story about Canadian educators and the journey of international teaching. In reading this work you will become familiar with dimensions of experience at what some international teachers call “education’s best kept secret”—international schools. Although international schools do not feature significantly in educational research, their impact on the lives of teachers who inhabit their classrooms is significant. In this dissertation you will discover how the Canadian teachers in this study narrate their reasons for considering international teaching, their experiences in obtaining overseas positions, their professional and personal perceptions of teaching abroad, their reasons for staying overseas, and what it means to come back to Canada. This metaphorical journey of international teaching encompasses three embedded narrative phases: leaving home, teaching abroad, and coming home. Along this journey of international teaching, Canadians share what it means to be a Canadian at global international institutions.
This study addresses a gap in the literature on international education: the perspectives of 110 Canadian teachers at three different stages of the journey of international teaching: (a) those considering positions at international schools, (b) those currently working abroad, and (c) those who have returned to Canada after overseas appointments. The stages and the borderlands along the journey provide the opportunity to find home in places both imagined and unanticipated. Interpreting this metaphorical journey through the tensions and possibilities that occur in the borderlands offers insight for both teacher education and teacher identity in local and global contexts.

abstract: My examining committee advised that the original work contained in the thesis be restricted and that I submit a revised manuscript to a publisher prior to making the work available publicly.

abstract: PhD


title: Intimacy Of Contact With People With Emotional Or Mental Health Problems And Expectation Of Negative Public Attitudes Toward People With Depression

contributor:
Stuart, Heather
Community Health and Epidemiology

subject:
Depression
Public Attitudes
Contact
Stigma

abstract: Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2014-10-31 16:15:00.291

abstract:
Background: Previous research has shown that there is an association between prior contact with a person with emotional or mental health problems and an expectation of negative public attitudes toward people with a mental illness. Expectation of negative public attitudes is an extra burden that is associated with mental illnesses.
Objectives: 1) Describe Canadians’ expectations of negative attitudes toward people with depression. 2) Examine the association between intimacy of prior contact with a person with emotional or mental health problems and the expectation of negative public attitudes towards those with depression.
Methods: Data from the rapid response portion of the 2010 Canadian Community Health Survey were used. There were 10,389 respondents. Exposure was divided into any prior contact and no prior contact and for further analyses any contact was sub-divided into most intimate contact (self, family member, friend, co-worker) or total number of types of contact (0, 1, 2, 3/4). Outcome was determined using a reduced version of Link’s Devaluation-Discrimination Measure. A stigma score was determined and the respondent was categorized into one of three groups based on score (low, moderate, or high expectations of negative public attitudes). Stratified analyses and ordinal regression were used to determine if Canadians were less likely to hold negative attitudes if they had prior personal contact with someone who had a mental illness and if negative attitudes were inversely associated with intimacy of contact.
Results: There was only one statistically significant result. Compared to those who had personally experienced a mental illness, those who identified knowing a co-worker with a mental illness had higher odds of expecting negative public attitudes (OR= 10.61, 95% CI: 1.41, 79.70), however, this may have been a spurious association owing to the large number of comparisons made.
Conclusion: In this study, with one possible exception, previous prior contact with a person with emotional or mental health problems was not associated with expectation of negative public attitudes toward people with depression.

abstract: This data is not yet published. I will make it publicly accessible when my supervisor and I have finished writing the papers.

abstract: M.Sc.


title: Surveillance, Subjectivity and Resistance at the Frontiers of Europe: A Materialist Analysis of the Greece-Turkey Borders

contributor:
Lyon, David
Sociology

subject:
Surveillance
The Greece-Turkey Borders
Irregular Migration
Migrant Activism
Migrant Subjectivity
Ethnography
Citizenship
Human Rights
Security
Materialism
Foucault
Althusser
Political Sociology
European Union Borders

abstract: Thesis (Ph.D, Sociology) -- Queen's University, 2014-11-25 13:45:02.98

abstract: The Greece-Turkey borders have become one of the main points of undocumented entry into the European Union since 2009. The borders operate through complex elements: historical processes that shape their structure, ideologies that legitimize their violent existence, techniques and technologies that allow them to be practiced over migrants, and migrants complying with or resisting these structures, ideologies, techniques, and technologies. In order to provide a comprehensive analysis of these complex elements of the border, this dissertation critically engages with Althusser’s aleatory materialism, Foucault’s analytics of power and other complementary theories, and it analyzes the four aspects of the border in individual chapters. 1. Structural-decentred aspects of the border: The dissertation analyzes the historical material processes of colonialism and racism and the contemporary material processes of neoliberal globalization and post-politics that enable the EU borders to function as a decentred totality and to exclude certain peoples and not others. 2. Practical aspects of the border: The dissertation analyzes how the border operates in practice with specific surveillance technologies (such as radar systems and EUROSUR mechanisms at the borderzones) and techniques (such as everyday racist violence in urban contexts) that produce specific biopolitical effects on migrants. 3. Subjective aspects of the border: The dissertation analyzes how migrants develop diverse subjectivities when confronted by the border’s material violence, including stranger subjectivity, abject subjectivity, religious subjectivity, nomadic subjectivity, and dissident subjectivity. 4. Contested aspects of the border: Drawing on the case of 300 Migrant Hunger Strikers in Greece, the dissertation analyzes the material conditions of possibility for political contestation of the border. The dissertation draws on fieldwork data collected from border authorities, migrants, NGO workers and political activists in Greece and Turkey in May-September 2012 and from secondary data from publicly accessible resources. This dissertation provides a complex and nuanced understanding of surveillance, borders, and migrant subjectivities and politics through putting an emphasis on how the border is practiced, on the experiences of the affected migrants, as well as on the deeper and enduring material structures that frame the practices of the border and experiences of the migrants.

abstract: This dissertation is restricted because it is being prepared for publication as a scholarly monograph.

abstract: PhD


title: Strategic Improvisation in Turbulent Times: The Role of Information Systems

contributor:
Chan, Yolande E.
Management

subject:
Configuration analysis
Strategy
Improvisation
Top management teams
IT capabilities
IS strategy
PLS
Case studies
Information systems

abstract: Thesis (Ph.D, Management) -- Queen's University, 2014-11-08 06:35:22.891

abstract:
To remain competitive in today’s highly dynamic environments, organizations often need to act rapidly. To deal with urgent issues, top managers have to rapidly assess and act upon opportunities and threats. Strategic improvisation, a dynamic capability defined as top managers’ ability to spontaneously and creatively integrate, build, and reconfigure internal and external resources and capabilities to address unpredictable and rapidly changing strategic opportunities and threats, may positively impact organizational processes and overall performance. Additionally, information systems (IS) may facilitate strategic improvisation. For senior managers, the effective use of IS may enable the detection of new opportunities and threats, while facilitating the exploitation of existing knowledge to address them.
Using the dynamic capabilities perspective, this research addresses three research questions: 1) To what extent do IS and technology enable effective strategic improvisation? 2) How do organizational, information and knowledge factors influence strategic improvisation? 3) What are the specific effects of strategic improvisation on organizational outcomes?
The research proceeded in two main phases. First, case studies were conducted in two highly dynamic industries, software and consulting. Top managers from four medium-sized Canadian organizations were interviewed, and interview transcripts analyzed and coded. The second phase of the project was a survey, with data collected from 143 top managers in 100 medium-sized Canadian organizations. Results were analyzed using two methods, structural equation modeling and crisp set qualitative comparative analysis.
This study benefits both research and practice. It contributes to the literature on IT impact by establishing the role played by two IT capabilities, IT infrastructure flexibility and information management/knowledge management (IM/KM) capability in enabling strategic improvisation, as well as the moderating role of IS/IT strategy, especially innovative IS/IT strategy.  This research benefits the improvisation research by studying improvisation at the top management level and demonstrating its impact on product/service flexibility, process flexibility and organizational learning. Findings also suggest that there are many ways to achieve strategic improvisation, through various configurations of organizational memory, IM/KM capability and IT infrastructure flexibility. Last, this research provides managers with practical recommendations on the most effective ways to develop a strategic improvisation capability.

abstract: This thesis is restricted to further protect the confidentiality and anonymity of the case study participants.

abstract: PhD


title: Thermoplastic-based conductive composites containing multi-wall carbon nanotubes aligned under the application of external electric fields

contributor:
Docoslis, Aristides
Kontopoulou, Marianna
Chemical Engineering

subject:
Composites
AC electric fields
Carbon nanotubes
Electrical conductivity
Filler alignment
Thermoplastic

abstract: Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2014-11-03 11:10:28.272

abstract:
The objective of this thesis is to prepare thermoplastic/multi-wall carbon nanotubes (MWCNTs) and to apply external alternating current (AC) electric fields to achieve enhanced conductivity and dielectric properties.
The first part of the thesis focuses on preparing polyolefin-based composites containing well-dispersed MWCNTs. MWCNTs are functionalized with a hyperbranched polyethylene (HBPE) using a non-covalent, non-specific functionalization approach and melt compounded with an ethylene-octene copolymer (EOC) matrix. The improved filler dispersion in the functionalized EOC/MWCNT composite results in higher elongation at break compared to the non-functionalized composite. However, the electrical percolation threshold and the ultimate conductivity of the composites are not affected considerably, suggesting that this functionalization approach leaves the inherent properties of the nanotubes intact.
EOC/HBPE-functionalized MWCNT composites are further subjected to external AC electric fields (35 – 212 kV/m), which induce the formation of aligned columnar structures, as evidenced by Scanning Electron Microscopy.  Experimentally acquired resistivity data are used to derive correlations between the characteristic insulator-to-conductor transition times of the composites and the electric field strength (E), polymer viscosity (η) and MWCNT volume fraction (ϕ).  A criterion for the selection of (η, E, ϕ) conditions that enable MWCNT assembly under an electric field controlled regime (minimal Brownian motion-driven aggregation effects) is developed.
The dielectric properties of the solidified aligned EOC/MWCNT composites are further studied using dielectric spectroscopy. Annealing of the composites at 160 oC results in the formation of interconnected structures, whereas electrification, using AC field of 71 and 212 kV/m induces the formation of aligned columnar structures. The electrified and annealed composites have increased real and imaginary permittivity compared to the as-compounded composite, resulting in improved conductivity and storage capacity. An equivalent circuit model is fitted to the experimentally obtained impedance data in order to correlate the effects of electric field and processing time to the dielectric characteristics of the treated composites.
Finally poly(ethylene succinate) (PESu) composites containing well-dispersed MWCNT were prepared by an in-situ polymerization method. Composite electrification results in improvements in the electrical conductivity by up to 12 orders of magnitude, and a retention of high conductivity in the solidified state.

abstract: PhD


title: Cardiovascular correlates of arousal and their relationship to saccadic behavior

contributor:
Munoz, Douglas P.
Neuroscience Studies

subject:
Heart Rate Variability
Pulse Oximetry
Heart Rate
Antisaccade
Sympathovagal Balance
Saccade

abstract: Thesis (Master, Neuroscience Studies) -- Queen's University, 2014-11-03 12:54:45.693

abstract: Understanding the effect of subject arousal on saccadic behavior can shed light on the mechanisms by which arousal influences executive and oculomotor systems. Increased vagal activity is a key component of the parasympathetic response, and is inversely associated with arousal. We designed two experiments to examine the relationship between saccadic reaction times (SRTs) and two cardiovascular correlates of vagal activity: heart rate (HR) and the normalized high-frequency (HFν) component of heart rate variability (HRV). In the first experiment, 11 normal human subjects performed a simple saccade task where they were asked to shift their gaze towards an eccentric target. In the second experiment, 19 subjects performed a counterbalanced and interleaved task where they were asked to look either towards (prosaccade) or away from (antisaccade) a visual stimulus. Experiment #1 aimed to probe the role of arousal on automatic oculomotor mechanisms, while Experiment #2 added an executive component. On the basis of data from these experiments, we propose the existence of two discrete mechanisms: a parasympathetic pathway that modulates automatic functions on a 25-minute timescale and another that modulates both executive and automatic functions on a 2 min timescale. We also postulate a mechanistic hypothesis for the neurovisceral integration of arousal, oculomotor behavior and cardiovascular parameters. These findings may allow concurrent pulse oximetry to be used for improving the fidelity of future oculomotor and other neurophysiological experiments.

abstract: M.Sc.


title: Calpain inhibitor design inspired by the natural inhibitor calpastatin

contributor:
Davies, Peter L.
Biochemistry

subject:
inhibitor
calcium-activated protease
macrocycle
protease
allosteric inhibitor
calpastatin
calpain
enzyme kinetics

abstract: Thesis (Ph.D, Biochemistry) -- Queen's University, 2014-11-07 14:42:07.019

abstract: Calpains are cysteine proteases that depend on Ca2+ for activation. They have many roles in the cell; hence modifications of calpains or changes in their levels of activity can lead to altered physiological states. Thus, it is of great interest and medical relevance to design inhibitors that can specifically target calpain without interfering with the other numerous cellular cysteine proteases. The cytosolic and ubiquitous calpains-1 and -2 have a naturally occurring and specific inhibitor, calpastatin, which binds with high affinity to the active site but in such a way that the calpastatin itself is not cleaved.  Crystal structures of the full-length calpain-2 in complex with calpastatin have aided the design of novel calpain-specific inhibitors. I have helped design cyclic peptides to mimic important conserved structural elements of calpastatin and have investigated their inhibition potency against calpain. Cyclic peptides and derivative peptidomimetics were able to inhibit cysteine proteases including calpain. Macrocycle and peptidomimetic products showed competitive, non-competitive, and mixed inhibition of calpain-2 with Ki values in the micromolar range while conferring some specificity. In a second strategy inhibitors mimicking the calpastatin subdomain B α-helical region were designed to be calpain-specific  by binding outside of the common cysteine protease active site cleft but extend into it. Indeed, stabilized α-helices synthesized from conserved calpastatin residues were found to inhibit calpain specifically and potently, with potential use as fluorescent activity-based probes. Previously reported allosteric inhibitors of calpain were investigated, and their ability to inhibit the calpain enzyme through binding to the PEF domain questioned. The compound PD150606 was able to inhibit the protease core of calpain, which lacks the PEF domain of the full enzyme, and the penta-peptide LSEAL was found to have no effect at all on calpain in vitro. Thus it is now clear that binding to hydrophobic grooves in the calpain PEF domains does not confer inhibition and the mechanism of non-competitive calpain inhibition is still unknown.

abstract: PhD


title: Queer and Unusual Space: White Supremacy in Slash Fanfiction

contributor:
Tolmie, Jane
Gender Studies

subject:
Whiteness
Social Media
Fandom
Fanfiction
Critical Race Theory
Queer Theory
Pop Culture
Affect Theory
Fan Studies

abstract: Thesis (Master, Gender Studies) -- Queen's University, 2014-11-05 15:48:44.304

abstract: My thesis exposes the ubiquity of white supremacy in the ostensibly queer practice of writing slash fanfiction.   Slash fandom is often characterized as a queer online space that foregrounds women’s pleasure and functions as resistance to hegemonic ideas about gender and sexuality.  Absent from this conceptualization is the presumption of whiteness that pervades fan imaginings.  I undertake a critical discourse analysis of slash fanfiction to reveal the homonationalist and white supremacist ideologies that underpin much creative fan work.  Utilizing the framework of affect theory, I then perform an intertextual analysis of comments from white fans that reveal the possessive investment in whiteness that is a powerful undercurrent in fan communities.  Finally, I examine critiques from fans of colour to theorize anger and creativity as strategies of resistance that have the potential to open up fan spaces so they may better realize their radical emancipatory potential.

abstract: M.A.


title: Beyond Moral Responsibility and Lesser-Evils: Moral Desert as a Supplementary Justification for Defensive Killing

contributor:
Gordon-Solmon, Kerah
Philosophy

subject:
Ethics of Self-Defense
Lesser-evil justifications
Defensive Harm
Moral Desert
Moral Responsibility
Liability

abstract: Thesis (Master, Philosophy) -- Queen's University, 2014-11-07 14:22:30.462

abstract: In recent years, philosopher Jeff McMahan has solidified an influential view that moral desert is irrelevant to the ethics of self-defense. This work aims to criticize this view by demonstrating that there are cases in which moral desert has a niche position in determining whether it may be permissible to kill a person in self- (or other-)defense. This is done by criticizing McMahan’s Responsibility Account of liability as being overly punitive against minimally responsible threateners (MRTs), and by demonstrating, through reference to Saba Bazargan’s Hybrid Account of liability to defensive harm, that further justification than mere liability is necessary in the justification of killing these kinds of threateners. It is also argued that other kinds of justifications like lesser-evil justifications are not necessarily strong enough to justify killing MRTs, even on top of established liability. This paper puts forward the view that, where a strong enough moral difference between threatener and innocent victim cannot be established, a justification on the basis of the implications of prior moral acts might, on some occasions, give us reasons to kill or not kill MRTs in self-defense.

abstract: M.A.


title: Numerical Modeling of the Effect of Sulfur Poisoning on the Performance of the Porous Anode Solid Oxide Fuel Cell

contributor:
Karan, Kunal
Chemical Engineering

subject:
Sulfur Poisoning
Numerical Modeling
Solid Oxide Fuel Cell (SOFC)

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2014-11-10 21:27:21.71

abstract: A numerical model to capture the effect of H2S impurities on the Solid Oxide Fuel Cell (SOFC) performance with Ni-based porous anode is developed. H2S impurities can adversely affect the fuel cell performance, due to the sulfur poisoning of the Ni catalyst of the SOFC anode. The novelty of this work is the derivation of a Butler-Volmer type kinetic formulation that captures the effect of sulfur poisoning on the H2 electro-oxidation reaction in the Ni-YSZ anode of SOFC. The novel kinetic model is then incorporated into a 2-dimensional porous anode model with gas-phase species transport, charged species transport and anode electrochemistry. The result is a performance model that can predict the effect of H2S impurity on the polarization curves of the SOFC by taking into account the transport phenomena in addition to the electrochemistry formulations. Two types of kinetic models named as “coverage dependent kinetic model” and “coverage independent kinetic model”, differing in the coverage dependency of energy of H2 and H2S adsorption reactions are developed and incorporated in the 2D porous anode model. Loss in performance is predicted by both kinetic models and 2D performance models. Both kinetic models predictions show an increase in the current density loss with an increase in H2S concentration. 2D performance models predictions with both coverage dependent and coverage independent models show an increasing trend in both the loss in the cell voltage and increase in the cell resistance upon the increase of the inlet H2S content of the fuel. The 2D performance model with coverage-dependent kinetics predicts lower loss in the cell performance than the 2D performance model with coverage-independent kinetics. By comparing the performance model predictions with the experimental results, similar trends of increase in the sulfur poisoning effect by increase in H2S content and smaller increase in the relative cell resistance at higher current densities can be recognized in both experimental results and the 2D model predictions. Coverage-dependent 2D performance model predictions are closer to the experimental results than the coverage-independent 2D performance model predictions.

abstract: M.A.Sc.


title: Adaptive Critic-based Control of Voltage Source Converters in Microgrid Systems

contributor:
Bakhshai, Alireza
Electrical and Computer Engineering

subject:
Power Electronics
Fuzzy Logic
Microgrids

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2014-11-11 11:32:10.637

abstract:
Control of microgrids, as the main building blocks of the future smart power grid, is an important problem which has initiated many research activities in recent years. The microgrid should appear to the power grid as a single united entity, in which the majority of distributed energy resources are interfaced through voltage source converters (VSCs). In dynamic situations, specific structure, natural nonlinearity, and low physical inertia of VSCs may lead to higher sensitivity to network disturbances and power oscillations and in occasions result in violation of overall stability; hence the need for fast and flexible control techniques in the microgrid is evident.
The design simplicity and easy implementation of PI controllers have resulted in their popularity in controlling VSCs; however their application is associated with a number of drawbacks such as poor harmonics attenuation and unsatisfactory operation in case of load changes and high penetration of distributed generators.
In this Ph.D. thesis, three different control algorithms are proposed for VSCs in microgrid systems. The control systems are based on the adaptive critic-based control concept and employ an element called critic whose task is to evaluate the credibility of the performance and compare it with the desired goals. The critic’s evaluations are then used in an on-line procedure to update the controller parameters during dynamic transients. The critic-based control idea is used in conjunction with PI and neuro-fuzzy controllers.
With the proposed approach, the need for precise design of the controller is removed, and because of the supervisory role of the critic, no complicated mathematical calculations are required for its design. This fact increases the degree of intelligence and adaptivity against changes such as high penetration of distributed generators and dynamically demanding situations like presence of motor loads and results in a self-tuning and non-model-based control system with high computational speed.
The simulation results verify that the application of the proposed approach significantly improves the dynamic performance by reducing the convergence time, output oscillations, tracking error, and unwanted current harmonics and confirm the effective control in case of high penetration of distributed generators.

abstract: PhD


title: From Old Mould to Functional Gold: The Adaptive Reuse of Surplus Heritage Schools in Hamilton, Ontario

subject:
Urban Planning
Hamilton, Ontario
Adaptive Reuse
Surplus Schools
Heritage Planning
School Board Disposition

abstract: This report examines the characteristics that hinder or facilitate the success of a surplus school to residential conversion in Hamilton, Ontario. This topic is especially relevant as many of the city's schools are likely to be declared surplus in the coming years, a number of which represent unique heritage building stock. The value in examining the completed adaptive school reuse projects in the city is that it can provide valuable insight into how the process currently functions and how it can be improved upon.


title: Optical And Acoustical Studies Of The Proposed PICO-250L Dark Matter Detector

subject:
Linear alkylbenzene
Bubble chamber
COMSOL
Dark matter
PICO
Superheated liquid

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2014-11-18 19:38:49.29

abstract:
In the first part of this work I explore the possibility of using linear alkylbenzene, the buffer liquid for the future PICO-250L detector, configured as a liquid scintillator that could provide information on the background radioactivity levels of the inner vessel. I investigate what interactions could produce scintillation light and determine their intensity and likelihood. I design different devices that help light collection and assess quantitatively their advantages and disadvantages.

In the second part of this work, I develop a 2D acoustical model of the inner vessel of the detector that reproduces the discrimination between alpha and neutron events characteristic of backgrounds in superheated liquid experiments. Such a model is crucial for understanding the propagation and reception of the acoustic signals in the chamber. Subsequently, I exploit this model to show that piezoelectric devices located in different part of the vessel yield different discrimination capability between single and multiple bubble events.

abstract: M.Sc.


title: Taxonomy for JavaScript Attacks

contributor:
Dean, Thomas R.
Computing

subject: Attacks Security JavaScript Taxonomy

abstract: Thesis (Master, Computing) -- Queen's University, 2014-11-24 10:32:21.362

abstract:
In the ubiquity era, each user has multiple devices; hence an attractive model is to have applications that execute in a client’s web browser instead of developing a native application for each device. JavaScript is the language of the browser and the power available in these devices has motivated developers to move functionality to the client side. This raises the question of securing JavaScript applications since code executed on the browser is visible in plain text to potential adversaries.
To identify the context in which JavaScript attacks take place, we discuss different styles of software architecture and conclude that the architecture relevant to our study is client/server with a monolithic, event driven client where a significant amount of the application’s logic sits on the client side.
We discuss threat modeling methodologies and explain how this thesis fits into the attack extraction phase of threat modeling and we define a taxonomy for JavaScript attacks.
We have collected a set of man in the middle attacks for JavaScript where the attacker actively eavesdrops on the connection. We have also included man at the end, or White Box, attacks where the attacker has control over both the execution platform and the software implementation. These attacks have been used in conventional programming languages and we have adapted them to JavaScript. White Box attacks have become significant in web applications due to the move of sensitive functionality to the client side and have especially been the concern of digital rights management.

abstract: M.Sc.


title: Ultrasound-guided Intervention for Prostate Cancer Detection

contributor:
Mousavi, Parvin
Computing

subject: Abstract

abstract: Thesis (Master, Computing) -- Queen's University, 2014-11-19 16:48:05.591

abstract:
Prostate cancer is the second most common cancer diagnosed in North American
men. It can be managed with a survival rate of over 90% if diagnosed early. Although diagnosis of prostate cancer is important, however not all the diagnosed cancers are life-threatening. Hence, accurate prognosis of prostate cancer is crucial to avoid over-treatment of patients with indolent disease. Recently, a novel ultrasound tissue typing
technique was proposed that utilizes ultrasound RF data acquired from a stationary
location of the tissue over time. The goal in this thesis is to present the feasibility
of characterizing aggressive prostate cancer using ultrasound RF time series. We
pursue this goal by analyzing data from two ex vivo and one in vivo studies involving
prostatectomy patients.In almost all of the ultrasound-based interventions, calibration of the ultrasound
probes is of crucial importance to determine the location of image plane in a global
coordinate system. Calibration is routinely performed by imaging a geometrically
known object. The calibration problem is then solved by relating the feature locations
in this object in the ultrasound images and their true locations. Recently a calibration
technique was proposed that eliminated the need for fabricating complex phantoms.
This technique is based on imaging a flat plate that is immersed into a water tank. In
this thesis, we also evaluate the robustness of this calibration by performing extensive experimental evaluations.
In the ex vivo studies, in a cross-validation framework, areas under the accumulated
receiver operating characteristic curve (AUC) of 0.8 and 0.85 were obtained
from 15 and 6 patients, respectively. The results are confirmed by performing a
gold-standard pathology to ultrasound registration. We also provide likelihood maps
showing the probability and extent of higher grade cancer in the entire cancerous
area of each patient. In the in vivo study on prostatectomy cases, an AUC of 0.88
is achieved on characterizing higher grade prostate cancer. The experimental evaluations
of single wall approach yielded reproducibility accuracy of 3.14 ± 1.5 mm.
Having a well-defined hand motion pattern for ultrasound probe movements and digitizing
the wall plane first can improve the robustness of this calibration framework.

abstract: M.Sc.


title: Synthesis and Reinforcement of Peroxide-Cured Butyl Rubber Thermosets

contributor:
Parent, J. Scott
Chemical Engineering

subject: Ionomers Nanocomposites Rubber Isobutylene

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2014-11-25 19:44:11.988

abstract: Isobutylene-rich elastomers provide the oxidative stability and impermeability required by many industrial applications.  Halogenated derivatives support a wide range of chemical modification processes that can overcome most performance limitations. This research involves the modification of brominated butyl rubber (BIIR) to introduce peroxide-curable functionality in addition to aminotrialkoxysilyl groups that improve interactions with siliceous fillers, and anthraquinone functionality that serves as a polymer-bound chromophore. The thesis also describes detailed studies of the influence of counter anions on imidazolium ionomer derivatives of brominated poly(isobutylene-co-p-methylstyrene) (BIMS).  Exchanging bromide with dodecyl sulfate, styrene sulfonate and montmorillonite clay platelets provided new ionomer thermosets whose rheological, tensile and adhesive properties varied considerably from their parent material.

abstract: M.A.Sc.


title: Adaptive Slope-Assist Maximum Power Point Tracking and Power Limit Search for Intelligent Power Management of Small Wind Energy Systems

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

subject:
Wind Energy
Power Management
Maximum Power Point Tracking

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2014-11-26 14:18:08.825

abstract:
Due to its high energy generation capability and minimal environmental impact, wind energy is an elegant solution to the growing global energy demand.  Though wind energy systems can yield large amounts of energy, frequent atmospheric changes make it difficult to effectively harness the energy in the wind because maximum power extraction occurs at a different operating point for each wind condition.  Therefore, maximum power point tracking (MPPT) control algorithms are used in wind energy systems to increase its power extraction efficiency.
Basic MPPT algorithms use pre-determined mathematical relationships that represent a specific wind system’s power/torque characteristics for maximum power capture. Due to system aging, the efficiency of these basic algorithms deteriorates over time since it cannot adapt to any system changes.  As a result, perturb and observe (P&O) parameter-independent algorithms were developed to actively search for the system’s optimal operating points by perturbing the system and observing the resultant behavior.   However, P&O algorithms are susceptible to logical errors when subjected to frequent atmospheric variations and ignore the effects of air density.
This thesis proposes a parameter independent intelligent power management controller that consists of a slope-assisted MPPT and a power limit search (PLS) algorithm for small wind energy systems.   The proposed MPPT actively searches for MPPs and establishes a maximum power curve (MPC) relationship that characterizes the behavior of the given wind turbine to assist in future MPP searches. The algorithm is robust to changes in wind speed and/or air density conditions by monitoring internal system behavior.  The slope assist MPPT uses an internally derived slope parameter to ‘remember and revert’ to the system’s last operating state before the atmospheric change to increase MPP search efficiency.
The controller’s PLS is able to minimize the production of surplus energy to minimize the heat dissipation requirements of the energy release mechanism.  The PLS seeks the operating points that result in the desired power rather than the maximum power.
Finally, the performance of the proposed algorithm was compared to that of the conventional P&O algorithms and the results have shown that the proposed MPPT can extract at least 10% more power.

abstract: PhD


title: Art and Business in Seventeenth-Century Naples:  The Collecting, Dealing and Patronage Practices of Gaspare Roomer

contributor:
Schütze, Sebastian
Dickey, Stephanie S.
Art History

subject:
Collecting
Art Market
Painting
Naples

abstract: Thesis (Ph.D, Art History) -- Queen's University, 2014-11-26 21:30:06.995

abstract: This thesis examines the cultural influence of the seventeenth-century Flemish merchant Gaspare Roomer, who lived in Naples from 1616 until 1674.  Specifically, it explores his art dealing, collecting and patronage activities, which exerted a notable influence on Neapolitan society.  Using bank documents, letters, artist biographies and guidebooks, Roomer’s practices as an art dealer are studied and his importance as a major figure in the artistic exchange between Northern and Sourthern Europe is elucidated.  His collection is primarily reconstructed using inventories, wills and artist biographies.  Through this examination, Roomer emerges as one of Naples’ most prominent collectors of landscapes, still lifes and battle scenes, in addition to being a sophisticated collector of history paintings.  The merchant’s relationship to the Spanish viceregal government of Naples is also discussed, as are his contributions to charity.  Giving paintings to notable individuals and large donations to religious institutions were another way in which Roomer exacted influence.  This study of Roomer’s cultural importance is comprehensive, exploring both Northern and Southern European sources.  Through extensive use of primary source material, the full extent of Roomer’s art dealing, collecting and patronage practices are thoroughly examined.

abstract: I plan to publish this thesis in the near future.

abstract: PhD


title: An Augmented Reality System for Arthroscopic Computer Assisted Mosaic Arthroplasty

contributor:
Stewart, James
Computing

subject:
Augmented Reality
Arthroscopic Surgery
Computer Assisted Surgery

abstract: Thesis (Master, Computing) -- Queen's University, 2014-11-27 22:16:53.436

abstract:
Arthroscopic procedures require a difficult mental coordinate transform between the instrument in the surgeon's hand and the image shown on a display mounted near the patient. Significant training and experience is required to become proficient.

This thesis describes an augmented reality (AR) system designed to assist a surgeon performing a knee cartilage repair procedure by superimposing the virtual surgical plan over the live camera feed. The overlay displays an outline of the patient's anatomy along with information to correctly align surgical tools.

A user study was conducted to evaluate the performance of residents and surgeons using the AR system. The study showed a significant worsening in performance across all metrics. The study indicated that the worsening was in large part due to the transition from a classical multiple display setup showing orthogonal views of the tools and anatomy to a single view setup with our augmented reality overlay.

abstract: M.Sc.


title: Origin and Significance of Middle Ordovician and Mississippian Calcarenites

contributor: Geological Sciences and Geological Engineering

subject: carbonates siliciclastics geology sedimentology

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-11-28 14:44:05.319

abstract: Calcarenites are common throughout geologic history, but the range of depositional settings and conditions under which they form is poorly constrained. This study compares physically structured calcarenites in the Mississippian of the Western Canada Sedimentary Basin, and the Ordovician of the northern Appalachian Basin. Calcarenites in these successions are used to reconstruct paleo-environments and postulate sequence-stratigraphic subdivisions. Mississippian sediments in the Western Canada Sedimentary Basin were deposited on a sub-thermocline mid to outer ramp where wave action predominated, producing oscillatory and combined-flow sedimentary structures. It is interpreted that occasional storm-generated currents produced offshore-migrating dunes. Cyclonic storms appear to have been rare due to the low latitude and west-coast location of the study area. Swell waves were instead more common, reworking sediment across the mid ramp. Comparatively, carbonate sands in the Ordovician Chazy Group are interpreted to have been deposited as a tropical transgressive system with contemporaneous siliciclastic and carbonate sedimentation. A mixed-lithology barrier-island system is interpreted to have migrated landward as relative sea level rose. Low-energy siliciclastic and carbonate sediments accumulated in the back-barrier lagoon and carbonate dune fields formed seaward of the barrier islands, covering lagoonal deposits along a wave ravinement surface. It is interpreted that the subaqueous dunes developed between storm and fair-weather wave bases due to residual tidal currents that were likely amplified by a regional funnel-shaped embayment and local bathymetric constrictions. As flooding continued, mixed wave and tidal, open-marine carbonates buried the subaqueous dune fields. Broader-scale implications can be drawn from both successions. Mississippian calcarenites suggest that swaley cross-stratification can form down to storm (or swell) wave base on carbonate platforms, and is not restricted to the shoreface as it is in siliciclastics. Furthermore, the deposits suggest that swell-wave deposits are also more likely to be produced in carbonate deposits because of in situ grain production. The Ordovician calcarenites are strikingly similar to those along transgressive, wave-dominated, siliciclastic shorelines, suggesting that barrier-island complexes and associated transgressive sand sheets could be an under-appreciated origin for other carbonate sands.

abstract: M.A.Sc.


title: Crossed-Array Transducer for Real-Time Three-Dimensional Ultrasound Imaging

subject:
medical imaging
apodization
pulser
ultrasound
three-dimensional
real-time
crossed-array
finite-element modeling
beamforming
piezocomposite

abstract: Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2014-11-28 16:36:25.565

abstract:
Volumetric ultrasound imaging can present numerous advantages to medical diagnostics, such as increased spatial context, better long-term patient tracking, and reduced imaging times. Creating three-dimensional ultrasound systems is complicated by the attendant increase in system complexity that is required to capture the additional data, and by pulse discrimination imposing repetition frequency limits from the fixed speed of sound in tissue. If the same principles utilized in two-dimensional cross-sectional imaging are applied directly to capture a volumetric data set, the electrical interface, system complexity, and acquisition times grow exponentially. An alternative volumetric imaging method that enables real-time three-dimensional ultrasound imaging using a crossed-array structure is presented in this thesis.

The crossed-array transducer developed in this thesis makes use of careful material design and optimization to increase sensitivity and eliminate artifacts. A fine-pitch 1-3 piezocomposite has been optimized for performance in this application. This is combined with a novel method for creating intrinsic apodization within the piezoceramic material. Direct manipulation of the material sensitivity was found to be necessary to eliminate an artifact  unique to the large defocused aperture being used: range secondary lobes.

An acoustic stack has been designed for the transducer that optimizes sensitivity and reduces manufacturing complexity. Traces on a flexible circuit are used to define the array elements and the polyimide substrate is acoustically integrated as a matching layer. A defocusing rubber lens is used to keep the unfocused axis from experiencing near-field effects.

Custom electronics are developed that incorporate a pulser and transmit beamforming system. The pulser uses a new circuit topology to create Ohmic grounding of the array elements when inactive. This is necessary in order to use the same substrate for both send and receive. A transmit beamformer and an advanced control interface have been developed that permit flexible testing using computer control, as well as stand-alone operation using focal data loaded through interchangeable cards.

The system is characterized by its C-scan radiation patterns, showing confinement along the beamformed axis of 0.42mm at 75mm imaging depth. The defocused axis exhibits a smooth defocused profile with a 6dB angular spread of 45 degrees.

abstract: PhD


title: Characterization of the interactions of baculovirus transcription and replication regulators by bimolecular fluorescence complementation

contributor:
Carstens, Eric
Microbiology and Immunology

subject: AcMNPV

subject: Protein complementation assay

subject: Baculovirus

subject: RNA polymerase

subject: Viral transcription regulation

abstract: Thesis (Master, Microbiology & Immunology) -- Queen's University, 2014-11-30 13:56:45.726

abstract: Baculovirus gene expression is temporally divided into early and late stages. Viral late expression factors (LEFs) are essential for the transition between the early and late transcriptional stages, as well as for late gene expression. A virus-encoded RNA polymerase (RNApol) transcribes late and very late genes. Four LEFs comprise the core viral RNApol sufficient for in vitro transcription: LEF-4, LEF-8, LEF-9, and P47. LEF-4 has triphosphatase, guanylyltransferase, and ATPase activities. LEF-8 and LEF-9 contain catalytic motifs that are conserved in the active sites of other multisubunit RNApols. These motifs are required for in vitro baculovirus RNApol transcription. P47 has no demonstrated enzymatic activity. How these four subunits associate in vivo within the viral RNApol complex and initiate transcription is undetermined, as is whether its transcription mechanism requires the host TATA binding protein (TBP). Viral DNA replication coincides with the transition between early and late transcription and it is closely associated with the regulation of late gene expression. Two LEFs essential for viral DNA synthesis, LEF-3 and P143, have also been implicated in the regulation of baculovirus RNApol transcription. Bimolecular fluorescence complementation (BiFC) assays were adapted to characterize the in vivo interactions of the viral RNApol subunits LEF-4, LEF-8, LEF-9, and P47, in the context of viral infection, as well as to investigate their potential interactions with viral DNA replication proteins LEF-3 and P143, and host Spodoptera frugiperda TBP. The proteins of interest were modified by N-terminal fusions of the Venus1 (aa1-158) or Venus2 (aa159-239) fragments of the Venus fluorescent protein. Recombinant plasmids and baculoviruses were constructed. Nuclear fluorescence was detected from all BiFC assays investigating the self-association and inter-subunit interactions of the viral RNApol. BiFC assays also suggested that the viral RNApol proteins interact with LEF-3, P143, and TBP. The potential effects of endogenous viral proteins and viral DNA on the detected protein-protein interactions are discussed. The results highlight extensive interactions between the core baculovirus RNApol subunits, possible roles of viral DNA replication proteins in the nuclear localization and transcription mechanism of the viral RNApol, as well as the involvement of host TBP in in vivo late stage transcription.

abstract: M.Sc.


title: Towards Provisioning Vehicle-Based Information Services

contributor:
Hassanein, Hossam S.
Takahara, Glen
Computing

subject:
Smart Vehicles
Intelligent Transport Systems
Public Sensing

abstract: Thesis (Ph.D, Computing) -- Queen's University, 2014-11-30 18:49:30.696

abstract:
Smart vehicles are considered key enablers for intelligent transport systems. They are equipped with components to enable services for vehicle occupants, other vehicles on roads, and third parties. In-vehicle sensors, diversified communication modules, and an on-board unit with high computing and storage capabilities enable the smart vehicle to work as a mobile resource of diverse scopes of services.
With the high benefits the public sensing paradigm brought to the application domain, there is interest nowadays to widen the scope of applications by engaging more resources in the sensing loop. Although smartphones have been the main players in this domain, their use suffers from limitations due to the scarcity of their on-board resources and their unpredictable mobility patterns. Concurrently, the plethora of on-board resources in smart vehicles along with their ubiquitous mobility are pushing towards utilizing them for providing remarkable public sensing services.
In this thesis, we unveil the different resources a smart vehicle can provide on roads or at parking lots highlighting diversified information services that can come into action through utilizing such resources. Motivated by the high rise of the public sensing paradigm, we propose a vehicular public sensing platform that aims at exploiting the sensing, storage, processing and relaying resources of smart vehicles for provisioning ubiquitous, sensing-based information services. As parts of the proposed platform, we present a collection of solutions to handle some challenges facing such use of vehicles for public sensing. Our proposed solutions involve a framework to handle reputation-aware recruitment and selection of smart vehicles for achieving desired coverage of an area of interest within a budget limit. In addition, the presented solutions involve a data delivery scheme that considers on-road caching and forwarding assistance in accessing the sensing-based vehicular resources targeting improving the incurred access cost and delay. Extensive performance evaluation is conducted showing the improvements achieved by the proposed solutions in their targeted objectives compared to other popular systems and schemes.

abstract: PhD


title: Rockmass Behavioural Uncertainty: Implications for Hard Rock Geotechnical Baseline Reports

subject:
Geotechnical Baseline Reports
Tunneling
Rockmass Characterization

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-11-30 23:45:46.953

abstract:
Geotechnical Baseline Reports (GBRs) have become a prevalent risk sharing mechanism on North American tunneling projects as they are based on the following risk allocation concept: the subsurface ground conditions described within the GBR are the financial responsibility of the Contractor, whereas encountered conditions which exceed those described belong to the Owner.  This interpretation is intended to reduce project bid prices due to subsurface ground conditions uncertainty and the geotechnical rationale for a differing site conditions claim.  However, recent tunnel project case studies have used the GBR as a risk transfer mechanism by presenting a conservative and/or limited interpretation of the expected ground conditions.  In particular, the expected ground conditions are described with a summary of the intact and rockmass properties and empirical rockmass classification systems.
This research has shown that the application of intact rock properties and rockmass classification systems to describe the various rockmasses along the tunnel alignment leads to rockmass behavioural uncertainty.  Empirical rockmass classification systems are not able to adequately capture the effects of geologic uncertainty and the collective impact of the individual controls on rockmass behaviour.
A new rock engineering design tool was developed which utilized geologic uncertainty and the capabilities of numerical modelling methods to predict and quantify rockmass behaviours.  The 3D Rockmass Behaviour Map reduces subsurface ground conditions uncertainty as the range of possible rockmass behaviours is presented as a function of the three critical geomechanics parameters.  Quantifying rockmass behaviours per tunnel domain demonstrates the effects of geologic uncertainty with rockmass behaviour mode switching.
GBRs should include this 3D Rockmass Behaviour Map and quantified rockmass behaviours as these tools reduce uncertainty in the expected ground conditions and provide a greater understanding of the anticipated rockmass behaviours.  Rather than using a conservative GBR which shifts subsurface ground conditions risk to a Contractor, this improved prediction of the expected ground conditions may result in better subsurface risk allocation, reduced construction contingencies, aid excavation means and methods selection, reduced geotechnical basis for a differing site condition claim, and provide greater certainty in the final project price and schedule.

abstract: M.A.Sc.


title: A population-based study on the use of radiation therapy versus surveillance in early stage seminoma in Ontario

contributor:
Mackillop, William J.
Peng, Paul Yingwei
Community Health and Epidemiology

subject:
Radiation Therapy
Population Based Study
Oncology
Surveillance
Health Services Research
Seminoma

abstract: Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2014-12-02 15:13:27.159

abstract:
ABSTRACT
Background: Stage I Seminoma is treated with surgery followed with either adjuvant radiation therapy (RT) or a period of surveillance. Surveillance has emerged as a preferred management method, however there have been no randomized controlled trials comparing RT and surveillance.
Aim: To describe the incidence, management, and outcome in early stage seminoma patients in Ontario over time. To examine the relationship between patient characteristics and post-operative management methods (adjuvant RT versus surveillance). To examine the relationship between post-operative management methods (adjuvant RT versus surveillance) and patient outcome.
Hypothesis: The adoption of surveillance as a management option post-orchidectomy has increased over time with no resulting decrease in overall survival in an Ontario population.
Material and Methods: We performed a retrospective population-based cohort study of patients with surgically resected seminoma in the Canadian province of Ontario between 1982-2004 using data from the Ontario Cancer Registry. The population was enriched for stage I by excluding patients with evidence of metastasis. Patients were divided into time cohorts of 4 -5 years in length. Multiple logistic regression was used to identify patient and system factors associated with the use of RT. Kaplan-Meier survival analysis was used to assess overall, cancer specific, and relapse free survival. Cox proportional hazards model was used to assess the effect of patient and system factors on patient survival.
Results: Age-adjusted seminoma increased from 2.25 per 100,000 males in 1980-1981 to 2.94 per 100,000 males in 2004-2005. Adjuvant RT use in early stage seminoma patients has declined from 88.9% in 1983 to 32.2% in 2004. There has been no significant
ii
worsening of overall, cancer specific or relapse free survival between patients diagnosed in 1982-1986 and those in later years. Controlling for other factors in a Cox proportional hazards model, no significant change in overall survival was found over time.
Conclusion: The incidence of seminoma has increased over time. Over the course of the study period, use of adjuvant RT has decreased. While controlling for other factors, there has been no significant decrease in overall survival. The decreasing use of adjuvant RT has not adversely affected these patient outcomes.

abstract: M.Sc.


title: Comprehensive Study of the Electrochemical Behavior of Polycrystalline Platinum Electrodes in Aqueous Solutions of Trifluoromethanesulfonic Acid

contributor:
Jerkiewicz, Gregory
Chemistry

subject:
Platinum
Trifluoromethanesulfonic acid
Fuel cell

abstract: Thesis (Ph.D, Chemistry) -- Queen's University, 2014-12-02 19:49:58.333

abstract:
Trifluoromethanesulfonic acid (CF3SO3H) is the smallest fluorinated sulfonic acid and serves as a model imitating the Nafion® ionomer of catalyst layers of polymer electrolyte membrane fuel cells (PEMFCs).  The difference in the electrochemical behavior of Pt in CF3SO3H, as compared to H2SO4 or HClO4, originates from the different anion nature.  Because PEMFCs operate in the potential range in which electrochemical reactions involving O and H occur, the thesis focuses on: (i) Pt electro-oxidation; (ii) H electro-adsorption; and (iii) electrochemical and chemical Pt dissolution.
Platinum electro-oxidation in 0.1 M CF3SO3H is studied at various polarization potentials (Ep), polarization times (tp) and temperatures (T).  The reaction mechanism is revised and expanded by taking into account possible interactions of cations, anions and water molecules with Pt.  A modified kinetic equation for the interfacial place exchange is proposed.  The application of the interfacial place exchange and the metal cation escape mechanisms results in the determination of the Pt–O surface dipole moment, as well as the potential drop (Vox) and electric field (Eox) within the oxide.  The platinum-anion interactions indirectly affect the surface electro-oxidation kinetics.
The under-potential deposition of H (UPD H) on Pt in CF3SO3H is investigated over a broad T range using cyclic voltammetry.  The general electrochemical adsorption isotherm is used to determine standard Gibbs energy, entropy, and enthalpy of electro-adsorption, and energy of the Pt‒HUPD surface bond.  The lateral interactions between HUPD adatoms are repulsive.
Platinum electro-dissolution in 0.1 and 0.5 M CF3SO3H, H2SO4, and HClO4 solutions is studied using potential cycling and inductively coupled plasma mass spectrometry.  The results demonstrate that the anion nature has no or negligible impact on Pt electro-dissolution; however, pH significantly affects the process and the higher the pH value the greater the electro-dissolution of Pt.  An analysis of potential versus pH diagrams (Pourbaix diagrams) for acid solutions of different concentrations demonstrates that dissolved Pt (present as Pt2+ and Pt4+) can form through anodic dissolution of metallic Pt, as well as through anodic electrochemical and chemical dissolution of PtO.

abstract: PhD


title: Measurement and Modelling of Vibration Characteristics of a Mining Skip During Unloading

contributor:
Mechefske, Chris K.
Mechanical and Materials Engineering

subject:
Vibrations
Mining Skip

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2014-12-02 23:16:26.963

abstract:
Arc gate skips can carry larger payloads compared to other designs due to the superior safety of the arc gate design, however these skips experience large amplitude vertical oscillations during unloading.  Data were collected from a salt mine with arc gate skips in operation to observe and gather information on the system.  Full scale computational simulations were developed to theoretically characterise and analyse the full scale system.  A small scale experimental apparatus was designed and fabricated to perform experiments, and complementary small scale computational simulations were also developed.
The analysis of every unloading cycle in the mine site data revealed the peak amplitude of the oscillations and damping constant varied considerably between unloading cycles, while the primary oscillation frequency remained relatively constant between cycles.  Each unloading cycle was categorised according to the six characteristic shapes observed in the oscillations.  Two cycles from each category were selected for further analysis.
The small scale experiments investigated the level of influence of the angle of the exit chute walls and floor, the number of internal stiffener bands, grain size distributions, and moisture content of the ore.  The experiments showed that an increase in ambient humidity and possible increase in moisture content of the ore caused the greatest increase in the oscillation amplitude, followed by the angle of the exit chute walls and floor with the optimum angle being 5° to 10° steeper than the current angles.  The stiffener band experiments revealed that removing all the stiffener bands gave the largest reduction in the oscillation amplitude.  Finer grain ore was found to reduce the oscillation amplitude, although it had the least significant effect in comparison to the other variables.
The full and small scale simulations confirmed that, when compared to the raw data from the mine and the control experiments, the system was best modelled as a single degree of freedom mass-spring-damper system with a linearly decreasing mass.
The high speed camera experiments revealed the stiffener bands created a plug effect with the ore close to the walls, causing ore-on-ore friction, whereas without stiffener bands the ore flowed together, resulting in ore-on-aluminium friction.

abstract: M.A.Sc.


title: Slip Heating in Polymer Processing

contributor:
Giacomin, A. Jeffrey
Chemical Engineering

subject:
slip heating
polymer extrusion

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2014-12-04 01:06:58.536

abstract: When one body slips on another, heat is generated at the slipping interface. We call this phenomenon slip heating and apply slip heating theory to cohesive and adhesive slip in extrusion dies. Adhesive slip, which is linked to melt fracture, is a breakdown of the no slip boundary condition at the die wall, where the fluid moves with respect to the wall. Die drool, the accumulation of plastic on the open die face, has been attributed to cohesive melt failure, which results in the formation of a bulk layer that slips on a drool layer. The corresponding isothermal analysis of cohesive slip led to an analytical solution for the drool rate [Schmalzer and Giacomin, J. Pol. Eng., 33, 1 (2013)]. We account for slip heating during adhesive and cohesive slip and develop analytical solutions for temperature rise with and without viscous dissipation. We focus on slit flow, used in film casting, sheet extrusion and curtain coating, and when curvature can be neglected, slit flow is easily extended to pipe extrusion and film blowing. In slit flow, the heat flux from the slipping interface is the product of the shear stress and the slip speed. We present the solutions for the temperature rise in pressure-driven and simple shearing flows, each subject to constant heat generation at the slipping interface. We find expressions for drool rate by modeling viscosity as an Arrhenius function of temperature, and we show how to correct wall slip data for the slip heating temperature rise. We conclude with worked examples showing the importance of slip heating in die drool and wall slip, and we find that slip heating suppresses drool. We also arrive at a necessary dimensionless condition for the accurate use of our results: Pé<<1.

abstract: M.A.Sc.


title: Managing Long-Running Queries Using A Query Progress Indicator

contributor:
Martin, Patrick
Zulkernine, Farhana
Computing

subject:
Query Progress Indicator
Execution Control
Workload Management System
Long-Running Queries

abstract: Thesis (Master, Computing) -- Queen's University, 2014-12-04 14:55:10.417

abstract:
Database management systems (DBMSs) are the essential tools to monitor and manage data and transactions in databases. Normally a database receives hundreds of requests, called workloads so dynamic workload management is an important component of an autonomic DBMS solution. Controlling concurrently running queries in DBMSs is one form of workload management which is called execution control and it aims to guarantee desired performance levels for queries with varying priorities.  One of the challenges in making such control-decisions is determining how much more processing time the query requires prior to completion. Query progress indicators attempt to estimate the progress of running queries.  This offers a means to identify the long-running queries at early stages, potentially before other important workloads are negatively impacted, and thereby, assists in making a better decision to select the appropriate execution control mechanism for handling long-running queries.

Our work illustrates a strategy and defines policies for making decisions based on a simple progress indicator that we implement in PostgreSQL, to select the time and type of execution control action to apply to recover from a declining workload performance in a DBMS. Based on the progress of the long running OLAP queries, they are either throttled or killed at different progress points to maximize system efficiency. We define a utility measure to indicate throughput recovery of the important workloads with respect to the increase in the total workload execution time. Our experiments show that throttling combined with a progress indicator results in faster and better system recovery.

abstract: M.Sc.


title: Reweaving the Urban Fabric: Examining Greyfield Redevelopment in the Greater Toronto Area

type:
learning object
thesis

subject:
Greyfields
Redevelopment
Urban Planning


title: Importance of Climate on Boreal Lakes from Northwest Ontario Over Millennia: A Paleolimnological Perspective

contributor:
Cumming, Brian F.
Biology

subject:
Holocene Period
Multiproxy
Boreal Lakes
Northwest Ontario
Water Quality and Quantity
Paleolimnology

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2014-12-08 09:48:12.956

abstract: The lack of long-term data on the response of boreal lakes to climate change has been seen as an impediment to the assessment of the vulnerability and risks that northwest Ontario faces in light of future climate change. The overall objective of this thesis was to provide a centennial-to-multi-millennial perspective on the impacts of past climate change on boreal lakes in northwest Ontario. Second chapter has resulted in the development and application of a paleoecological model, based on the modern-day distributions of chironomid assemblages to lake depth, in a small boreal lake. Changes in the chironomid assemblages provided significant and strong support for the diatom-based inference techniques that estimated lower water levels, and consequently drought-like conditions, throughout northwest Ontario during the Medieval Climate Anomaly. Third chapter provides evidence that supports an early-to-mid-Holocene period of aridity, with reduced water levels across the boreal region in northwest Ontario. This conclusion was based on changes in diatom assemblages in well-dated sediment cores from three lakes spanning a distance of ~200 km across the boreal forest region. During the early-to-mid-Holocene, benthic diatom taxa predominate in all cores, suggesting lower lake levels by ~2-5 m, when compared to modern-day diatom assemblages from these lakes. Increases in planktonic diatom taxa to greater than 50% of the entire assemblage, occurs beginning ~4500 to 4000 cal yr BP, suggesting positive water balance over the last 4000 years in comparison to the mid-Holocene period. Fourth chapter provides evidence of enhanced primary production and higher abundances of cyanobacteria in three northwest Ontario lakes during the warmer early-to-mid-Holocene in northwest Ontario. This later study was based on changes in lake-water primary production from fossil pigments, spectrally-inferred chlorophyll a, and diatom assemblages in well dated cores, taken from the main central basin of the three study lakes. The majority of indicators show a coherent pattern of enhanced primary production during the early-to-mid-Holocene period, with elevated concentrations of cyanobacterial pigments in two of the three lakes. If conditions become warmer and drier in the future in northwest Ontario, challenges associated to water quantity and quality should be expected.

abstract: PhD


title: Genetic Evidence for Differential Activities of Goa Isoforms in Drosophila Melanogaster

contributor:
Seroude, Laurent
Biology

subject:
Drosophila
G-Protein
Wing Maturation
Haloperidol
G-Alpha

abstract: Thesis (Master, Biology) -- Queen's University, 2014-12-12 15:07:22.449

abstract:
Mental illness is prevalent in our population and has been studied for decades but is still poorly understood. Understanding the genetic and biological mechanisms underlying these disorders can lead to significant improvements in diagnosis, treatment, and quality of life for patients suffering from mental disorders.
Goα47A is a candidate gene in a putative haloperidol-affected pathway that is highly expressed in the nervous system. The gene encodes nine transcripts and two isoforms, which are 98% identical and differ only in the N-terminal region. However, the individual roles for each of the two different proteins have not yet been discerned. Transgenic strains of Drosophila melanogaster were generated using cDNA constructs corresponding to each of the two open reading frames (ORFs) under the control of UAS promoters. Expression of these transgenes was driven by a GAL4 driver with a similar spatial expression pattern to that of Goα47A. These constructs were intended to be used in a genetic rescue in order to test the hypothesis that a mutant allele of Goα47A causes resistance to the antipsychotic haloperidol.
In the course of generating strains needed for the rescue, it was found that the expression of either ORF causes a crumpled wing phenotype and lethality, both with variable penetrance. This variability is likely due to expression level, since GAL80 can reduce the frequency of these phenotypes. Additionally, there is an interaction between the ORFs and the TM3 balancer, which could indicate an interaction between Goα and a gene that is affected by the chromosomal rearrangements associated with the TM3 balancer. The majority of VD1 strains display crumpled wings and the expression of ORF1 can cause lethality. In contrast, two copies of the ORF2 transgene are required to cause crumpled wings. The difference in activities between the two ORFs is likely due to the few changes in the N-terminal region of the protein, which is presumably involved in the interaction with the β and γ subunits.  This finding suggests that small differences in a G-protein are sufficient to alter protein-protein interactions and subsequent signalling.

abstract: M.Sc.