VictorJuiz/thesis huggingface dataset:
Development of Novel Cell Fate Control Gene Therapy for Applications in Cancer and Immune Disorders
Keywords: Gene Therapy
Cell Therapy
Lentiviral Vectors
GvHD
Allogeneic Transplantation
Cancer
Immunology

Cellular therapies rely on the delivery of therapeutic cells into patients, but their safety can be compromised by the manipulation of cells ex vivo or their placement outside of their natural context in vivo. Cell Fate Control Gene Therapy (CFCGT) offers the possibility of establishing pharmacological controls over gene-modified cells (GMCs) with regards to their proliferation, differentiation, or function. In its simplest form, 'suicide' gene therapy (SGT), stable introduction of a 'suicide' gene that can activate a non-toxic prodrug establishes control over the survival of GMCs. Current SGT modalities are sub-optimal in clinical setting. To overcome the many limitation of current strategies, we have developed a next-generation CFCGT approach based on the active site-engineered variants of human deoxyCytidine Kinase (dCK), which enable robust activation of multiple Nucleoside Analogue (NA)-based prodrugs, act early in the pathway enabling rapid accumulation of activated NAs in target cells, and also provide the capabilities for the direct imaging of GMCs. Stable introduction of dCK variants into target cells by means of Lentiviral (LV) gene transfer significantly increases their sensitivity to multiple prodrugs. Our dCK variant with only two active site amino acid substitutions is expected to be non-immunogenic yet capable of specifically activating deoxythymidine- and deoxyuridine-based NAs that are not substrates for the wild-type enzyme, such as bromovinyldeoxyuridine (BVdU) and L-deoxythymidine (LdT). We show here that dCK can be used for controlling the survival of GMCs, in cell lines and primary cells in vitro and in a murine xenogeneic transplant models in vivo. To characterize dCK/prodrug-mediated killing mechanisms in GMCs, we have examined the levels of active metabolites in cells and the cellular pathways they antagonize. We describe here the experimental basis for the application of this novel CFCGT in bone marrow transplantation for management of Graft-versus-Host Disease (GvHD) and in enhancing chemotherapy in direct treatment of tumors. In summary, we have developed a novel and robust strategy for effective CFCGT that addresses the many shortcomings of existing modalities. Future studies will validate this novel system in a variety of primary cells and animal disease models, including models of hematopoietic transplantation and ES/iPS-based cell therapies.
Climate Change in the Canadian Boreal Forest: The Effect of Warming, Frost Events, Cloud Cover and CO2 Fertilization on Conifer Tree Rings
Keywords: Canada
climate change
boreal forest
dendrochronology

Anthropogenic climate change is expected to dramatically affect boreal forests, not only through warming effects, but through changes in seasonal and diurnal temperature patterns, precipitation, cloud-cover, and direct effects of rising CO2. My doctoral research examines the impact of these changes on dominant boreal forest conifer species, using dendrochronological methods. Through my analysis of white spruce (Picea glauca) and lodgepole pine (Pinus contorta) tree rings across five Yukon Territory sites, I found that white spruce growth is showing growth declines in response to all three measured climate changes, with negative correlations between tree ring increment and spring and summer temperature, spring frost events, and growing season cloud cover. Lodgepole pine populations exhibited growth enhancement with increasing spring maximum daily temperatures, but generally neutral responses to warming summers, higher frost event frequency and increased cloud cover. To evaluate the effect of rising CO2 on boreal forest growth, I examined three representative managed forest stands across Canada, first building a model of climate effects, and examining temporal trends in the residual growth patterns. I found evidence for CO2 fertilization in Ontario black spruce (Picea mariana) and Manitoba white spruce populations, particularly at younger ages, but no growth enhancement in Yukon lodgepole pine. These results taken together suggest that Yukon white spruce may suffer pronounced growth declines under continued climate change, but more eastern spruce populations may be better able to benefit from increased carbon availability. Yukon lodgepole pine populations are less vulnerable to the impacts of climate change, but are also unlikely to exhibit significant growth increases in response to increasing temperature, frost events, cloud cover or rising CO2. The results from this thesis have important implications for future management of the Canadian boreal forest under progressive climate change.
Abiotic Conditions in Contrasting Environments: An Examination of Precambrian Shield Lotic Communities
Keywords: community ecology
fish
macroinvertebrates
Precambrian Shield
Ontario

The inherent complexity of the natural world has long been a central theme in ecological research, as the patterns and processes that govern ecosystems can operate at multiple spatial and temporal scales. It is clear that to develop general ecological frameworks, we must consider many different factors at different scales, and incorporate ideas from other disciplines. This thesis touches on several of these ideas, first through an analysis of literature, and then with field research examining the role of broad-scale abiotic factors on lotic systems. To determine how integrated aquatic science is currently understood among different researchers, I provide an analysis on communication and exchange of ideas among various subfields in aquatic science. I show that there are clear divisions within the aquatic science literature, suggesting that there is progress to be made on the integration of methods and ideas. Next, I examine the impact of a large-scale geological feature, the Canadian Precambrian Shield, on abiotic conditions in lotic systems, and how these conditions in turn influence the species assemblages of aquatic organisms. This is addressed with both historical survey data, as well as contemporary data, and as a whole, incorporates ideas concerning the relative influence of regional versus local factors, the importance of historical factors on species distributions, and the relationship between the abiotic environment and biological communities. These analyses show that there are distinct fish and macroinvertebrate communities in Shield lotic systems compared to those found in nearby off-Shield sites, indicating that the Shield is an important broad-scale factor influencing local biological communities. This finding, in conjunction with previous knowledge on the influence of historical factors, provides further insight on the structuring of lotic fish and macroinvertebrate communities in Ontario.
Race, Resistance and Co-optation in the Canadian Labour Movement: Effecting an Equity Agenda like Race Matters
Keywords: racism and organized labour
organizational resistance and cooptation
race and gender
labour education
Canadian labour movement
race, power and trade unions
white privilege and labour unions
racialized women and trade unions

The purpose of this research project was to analyze the dialectic of co-optation/domestication and resistance as manifested in the experience of racialized Canadian trade unionists. The seven research participants are racialized rank-and-file members, elected or appointed leaders, retired trade unionists, as well as staff of trade unions and other labour organizations. In spite of the struggle of racialized peoples for racial justice or firm anti-racism policies and programmes in their labour unions, there is a dearth of research on the racialized trade union members against racism, the actual condition under which they struggle, the particular ways that union institutional structures domesticate these struggles, and/or the countervailing actions by racialized members to realize anti-racist organizational goals. While the overt and vulgar forms of racism is no longer the dominant mode of expression in today’s labour movement, its systemic and institutional presence is just as debilitating for racial trade union members. This research has uncovered the manner in which the electoral process and machinery, elected and appointed political positions, staff jobs and formal constituency groups, and affirmative action or equity representational structures in labour unions and other labour organizations are used as sites of domestication or co-optation of some racialized trade unionists by the White-led labour bureaucratic structures and the forces in defense of whiteness. However, racialized trade union members also participate in struggles to resist racist domination. Among some of tools used to advance anti-racism are the creation of support networks, transgressive challenges to the entrenched leadership through elections, formation of constituency advocacy outside of the structure of the union and discrete forms of resistance. The participants in the research shared their stories of the way that race and gender condition the experiences of racialized women in the labour movement. The racialized interviewees were critical of the inadequacy of labour education programmes in dealing effectively with racism and offer solutions to make them relevant to the racial justice agenda. This study of race, resistance and co-optation in the labour movement has made contributions to the fields of critical race theory, labour and critical race feminism and labour studies.
Flexible Distributed Business Process Management
Keywords: publish/subscribe
business process

Many large business processes are inherently distributed, spanning multiple organizations, administrative domains, and geographic locations. To support such applications, this thesis develops a flexible and distributed platform to develop, execute, and monitor business processes. The solutions utilize a distributed content-based publish/subscribe overlay that is extended with support for mobile clients and client interest churn. Over this layer, a distributed execution engine uses events to coordinate the execution of the process, and dynamically redeploys activities in the process in order to minimize a user-specified cost function and preserve service level agreements (SLAs). Finally, a management layer allows users to find and automatically compose services available across a distributed set of service registries, and monitor processes for SLA violations. Evaluations show that the distributed execution engine can scale better than alternate architectures, exhibiting over 60% improvements in execution time in one experiment. As well the system can dynamically redeploy processes to reflect changing workload conditions and SLAs, saving up to 90% of the process messaging overhead of a static deployment.
Regulation of Metalloproteinase-dependent Ectodomain Shedding in Cytokine Biology and Inflammation
Keywords: Immunology
Genetics
Metalloproteinase
Cytokine
Inflammation
Signaling

In 1962, Gross and Lapiere described collagenolytic activity in the degradation of tadpole tails during amphibian metamorphosis. This activity was later attributed to a collagenase enzyme belonging to the matrix metalloproteinase family. Over the past 49 years, steady growth in the field of metalloproteinase biology has uncovered that degradation of extracellular matrix components represents only a fraction of the functions performed by these enzymes. The regulatory roles of these enzymes in numerous aspects of mammalian biology remains poorly understood. This thesis investigates the metalloproteinase ADAM17 and its natural inhibitor TIMP3 in acute and chronic inflammation. My work describes the generation of new murine experimental systems of compartmentalized ADAM17 or TIMP3 deficiency and their applications in acute liver inflammation (i.e. fulminant hepatitis and T-cell mediated autoimmune hepatitis) and atopic dermatitis. Loss of Timp3 protected mice against fulminant hepatic failure caused by activation of the death receptor Fas. We determined that TIMP3 simultaneously promotes pro-apoptotic signaling through TNFR1 while suppressing anti-apoptotic EGFR activation in the liver. Mechanistically, we identified that ADAM17 is critical in shedding TNFR1 and EGFR ligands (e.g. Amphiregulin, HB-EGF, TGF) and extended this finding to clinically relevant drug-induced hepatitis. Adult TIMP3 deficient mice also exhibited spontaneous accumulation of CD4+ T cells in the liver. Consequently, polyclonal T cell activation with the lectin Concanavalin A (con A) in a model of autoimmune hepatitis resulted in accelerated liver injury. We identified that this immunopathology relied on TNF bioavailability as mice lacking both Timp3 and Tnf were resistant to con A. Using bone marrow chimeras we established that non-hematopoietic tissues were the physiologically relevant source of TIMP3 in vivo, thereby highlighting an immunosuppressive role for this stromal metalloproteinase inhibitor in cellular immunity. Finally, we investigated epithelial:immune crosstalk in the epidermis by generating tissue-specific ADAM17 deficiency in basal keratinocytes. These mice developed spontaneous inflammatory skin disease that was physiologically consistent with atopic dermatitis. Focused investigation of keratinocyte-specific signaling deregulated by ADAM17 deficiency revealed its requirement for tonic Notch activation, which in turn antagonized transcriptional activity of AP-1 transcription factors on the promoters of epithelial cytokines TSLP and G-CSF. In summary, these works identify cellular mechanisms governing cytokine-mediated communication between epithelial and immune cells to modulate inflammation. The findings that TIMP3 and ADAM17 act as regulators of key inflammatory, proliferative and developmental pathways provide impetus to expand our understanding of this important family of enzymes in mammalian signal transduction.
The Importance of Thermal Habitat Quality for Pumpkinseed (Centrarchidae: Lepomis gibbosus) in Small and Constructed Coastal Embayments Along the Northwest Shoreline of Lake Ontario
Keywords: Aquatic
Fisheries
Coastal Embayments
Lake Ontario
Toronto
Great Lakes

Along the Toronto shoreline, small coastal embayments (0.4 – 32 ha) are being constructed or modified to restore warmwater fish habitat. I describe how Lake Ontario (hereafter the Lake) alters the thermal regime of these small coastal embayments, how the altered thermal regimes affect growth and survival of age-0 warmwater fishes, and how the thermal habitat quality for such fishes can be improved by altering embayment design. During the warming period of the ice-free season, embayments warm faster than the Lake and so are cooled by exchanges with the Lake. Later in the year Lake exchange warms the rapidly cooling embayments, but the net effect of Lake-embayment exchange is cooling. The degree of cooling in Toronto’s small coastal embayments varies; many have temperatures near that of the Lake, and a few warm as much as local ponds. Age-0 pumpkinseed (Lepomis gibbosus) can fail to reach sufficient size to survive the winter in cooler embayments because their spawning is delayed and their growth is slowed. Most embayments along the Toronto shoreline are too cold to produce age-0 fish that can survive the winter, but all embayments are occupied by age >1 pumpkinseed, suggesting movement from warmer to cooler embayments. Using otolith microchemistry to identify natal embayments of fish, I confirm that age-0 and age-1 pumpkinseed, as well as age-0 largemouth bass (Micropterus salmoides) and age-0 yellow perch (Perca flavescens), exist in metapopulations. Embayment bathymetry is a poor predictor of temperature because almost all embayment flushing rates are very fast, usually 1-2 days. Warmer embayments are located in protected areas of Lake Ontario and receive waters that have already heated substantially. Cold embayments are located along the exposed shoreline of Lake Ontario. To protect embayments from cold lake waters, the cross-sectional area of embayment channels need to be reduced to 1-10% of their current size.
Interorganizational Partnerships, Leadership, Structures, and Processes: A Case Study of the Arab Bureau of Education for the Gulf States (ABEGS)
Keywords: Education
Leadership
Interorganizational Partnership
Partnership
Educational Administration
Arab Bureau
ABEGS
Circular Model of Interorganizational Leadership
Leadership Model
Circular Model

The purpose of this study was to identify factors that influence leadership and its distribution in the Arab Bureau of Education for the Gulf States (ABEGS) Saudi Arabia. The research was undertaken in the ABEGS as a case study and its two initiatives, the Gulf Arab States Educational Research Centre (GASERC) Kuwait, and the Arab Educational Training Centre for Gulf States (AETCGS) Qatar respectively. The findings of this study reveal that the leadership in this interorganizational environment is distributed within the four levels of organizational structures. The visionary leadership comes from the inner most core political level that has its influence and direction at the strategic, managerial, and operational levels of the organization. . Based on extensive research of Leithwood and his colleagues, this study will integrate four leadership functions of setting directions, structuring the organization, developing capacity, and managing the (partnership) program into the analysis of interorganizational partnerships. The study also examined ‘securing accountability’ as another important leadership function in the partnership environment. I learnt that multiple factors influence leadership and enable different individuals and groups to perform these functions at the strategic, managerial and operational levels of the interorganizational structures. However, the major influence on leadership that weaves through the strategic level to the grassroots levels is the consultative process embedded in the organizational structures of the Arab Bureau. Some other prominent factors that influence leadership found in the study are positional power in the hierarchy, experience and knowledge, and dedication and commitment. Researchers like Benson, Mawhiney, Kickert, Proven, and Rodríguez, explored interorganizational partnerships and view the structures of leadership either vertically centralized or horizontally distributive. I argue that interorganizational leadership works horizontally at each level of the partnership i.e. strategic, managerial, and operational and vertically between these levels in the ABEGS partnership as shown in the ‘Circular Model of Interorganizational Leadership’ of this study. The leaders at various levels in the Arab Bureau from the member states function as equals. However, firm vertical hierarchy exists between various levels in the structures of the ABEGS. It is therefore established that horizontal and vertical leadership work simultaneously in interorganizational partnership environments as found in the case study of the Arab Bureau.
Molecular Basis of Abnormal Conduction in Mice Over-expressing Endothelin-1
Keywords: heart failure
endothelin-1
cardiac electrophysiology
ion channels

Binary transgenic (BT) mice with doxycycline (DOX)-suppressible cardiac-specific over-expression of endothelin 1 (ET 1) exhibit progressive heart failure, QRS prolongation, and death following DOX withdrawal. However, the molecular basis and reversibility of the electrophysiological abnormalities in this model were not known. Here we assess the mechanisms underlying ET 1 mediated electrical remodelling, and its role in heart failure. Prior attempts to prevent this model of ET-1 induced cardiomyopathy with ET receptor antagonism were not beneficial. We now propose to evaluate the effectiveness of blocking the synthesis of ET-1 with CGS 26303, a dual inhibitor of endothelin converting enzyme (ECE) and neutral endopeptidase. BT vs. littermate control mice were withdrawn from DOX and serially studied with ultrasound biomicroscopy, octapolar catheters, multi-electrode epicardial mapping, histopathology, Western blot, immunohistochemistry and qRT-PCR. Prolonged ventricular activation and depressed rate of ventricular activation were detected as early as 4 wks after transgene activation, when structure and function of the heart remained unaffected. By 8 wks of ET-1 over-expression, biventricular systolic and diastolic dysfunction, myocardial fibrosis, cardiomyocyte hypertrophy, prolonged ventricular activation and repolarization, depressed rate of ventricular activation, and abnormal atrioventricular nodal function were observed. Within 4 wks of ET-1 induction, reduction were observed in connexin-43 mRNA, protein, and phosphorylation, Nav1.5 mRNA and protein, Na+ conductance, K+ channel interacting protein-2 mRNA and Kv4.2 mRNA. Chromatin immunoprecipitation revealed that nuclear factor κB preferentially binds to Cx43 and Nav1.5 promoters. Importantly, the associated electrophysiological abnormalities at this time point were reversible upon suppression of ET 1 over-expression and completely prevented the development of structural and functional remodelling. Treatment with CGS-26303 (5 mg/kg/day) failed to improve survival, or hemodynamic and contractile decline. ET-1-mediated ventricular conduction delays correlates with gap junction and ion channel remodelling, and precedes heart failure. The sequence and reversibility of this phenotype suggest that a primary abnormality in electrical remodelling may contribute to the pathogenesis of heart failure. CGS 26303 failed to prevent this cardiomyopathic phenotype. These data suggest that chronically high levels of bigET-1, as seen in heart failure, may induce increased ECE activity and/or non-ECE ET-1 synthesis, thus circumventing the efficacy of ECE blockade in this model.