Digital Commons Network^™

Optimum Design Of Cable-Stayed Bridges, Mahmoud M. Hassan

Digitized Theses

Owing to their excellent structural characteristics, aesthetic appearance, low maintenance cost, and efficient use of structural materials, cable-stayed bridges have gained much popularity in recent decades. Stay cables of a cable stayed bridge are post-tensioned to counteract the effect of the bridge dead load. The solution for an optimum distribution of post-tensioning cable forces is considered one of the most important and difficult tasks in the design of cable-stayed bridges. A novel approach that utilizes the finite element method, B-spline curves, and real coded genetic algorithm to determine the global optimum post-tensioning cable forces is developed. The effect of geometric …

A Biomechanical Explanation For Convergent Head Movements Evoked By Stimulation Of The Primate Supplementary Eye Fields, Michael Allan Pace

Digitized Theses

Cortical microstimulation has played an important role in the investigation of movement coding in the frontal and supplementary eye fields (FEF and SEF). Recent evidence has shown that microstimulation of the SEF produces eye head gaze shifts whose kinematics depend on initial position. Across different stimulation sites in the

SEF, evoked movements converge in a variety of reference frames, possibly reflecting the SEF’s role in complex sensory-motor transformations. Here, we examine neck muscle activity evoked by SEF stimulation while monkeys attained a range of different initial positions through electromyographic (EMG) recordings of the neck muscles. A similar approach targeting the …

A Case Study Of A Regional Youth Festival Of The Arts, Wendy Ruth Carter

Digitized Theses

The release of The Ontario Curriculum Grades 1-8, The Arts by the Ministry of Education in 2009 raises questions about how schools and principals can endeavour to deliver that curriculum to students in this era of significant funding cuts. In this context, the thesis explores a case study of a Regional Youth Festival of the Arts (RYFA), with a focus on two research questions: 1) In what ways are the arts education experiences of the RYFA similar to, and different from, school-based arts education? and 2) In what ways might the RYFA experience serve as a model for school-based arts …

An Emerging Theory On The Interaction Between Requirements Engineering And Systems Architecting Based On A Suite Of Exploratory Empirical Studies, Remo N. Ferrari

Digitized Theses

Requirements Engineering and Systems Architecting are often considered the most important phases of the software development lifecycle. Because of their close proximity in the software development lifecycle, there is a high degree of interaction between these two processes. While such interaction has been recognized and researched in terms of new technology (particularly methods and tools), there is a distinct lack of empirical understanding regarding the scientific properties of this interaction. Furthermore, in Requirements Engineering and Systems Architecting, not only technical but human aspects are considered critical for the success of these processes due to these processes lying at the front-end …

A Scale-Dependent Examination Of Stopover Decisions In Migratory Passerines At Long Point, Ontario, Stuart Alexander Mackenzie

Digitized Theses

Stopovers, periods o f rest and refuelling between migratory flights, play an integral role in determining fitness o f migrating passerines. Migration success is dependent on decisions made about when to arrive and leave particular stopover sites and how to utilize regional landscapes. I used mark-recapture analysis o f bird banding data from a stopover site and direct measurements from radio telemetry data covering a stopover landscape of~20 x 40 km at Long Point, Ontario, to examine stopover decisions. Specifically, I estimated probabilities that individuals would leave a site in relation to age, fat stores, season, and the extent to …

A Microarray Study On Gene Expression Of Drosophila Melanogaster 'M Response To Multiple Cold Exposures, Jian Zhang

Digitized Theses

In the field, insects suffer multiple cold exposures during winter. When exposed to repeated low temperatures, Drosophila melanogaster females show an increase in survival, but a reduction in reproduction. In this study, microarrays were used to analyze the gene expression of female D. melanogaster after multiple, single sustained (or single prolonged) and single short cold treatments, which exposed the flies at 0 °C for repeated 2 h, single 10 h and single 2 h respectively. Candidate genes involved in the 6 h recovery from different types of cold exposures were identified. After repeated cold exposures, candidate genes particularly included those …

A Survey Of Health-Related Services In Ontario’S Youth Custody Facilities, Lisa S. Cossy

Digitized Theses

This survey collected information on the nature and extent of health-related services in Ontario’s youth custody facilities and examined how the services provided compare with standards recommended by the Canadian Paediatric Society and the World Health Organization for the health care of youth in custodial facilities. The results reveal that the facilities appear to be observing most of the recommendations from the Canadian Paediatric Society and the World Health Organization. There is considerable variation in the services provided across the facilities, and secure custody facilities have a greater variety of services available. Service provision appears to be related to a …

Cathepsin B-Mediated Autolysosome Efflux And Cell Death, Boram Ham

Digitized Theses

Autophagy is a vesicular system which is a lysosomal degradation pathway found in organisms ranging from yeast to mammals. To date, extensive studies have unraveled the mechanism of autophagy biogenesis and more than thirty autophagy related (ATG) genes have been identified. However, detailed molecular mechanisms of autophagic process have not yet been elucidated. This study uncovered a novel role of cathepsin B (CTSB), a lysosomal protease, in autolysosome clearance, termed autolysosome efflux. CTSB-deficient immortalized and primary macrophages showed higher accumulations of autophagy specific protein microtubule-associated protein 1 light chain 3(LC3)-II and they showed greater numbers of FITC-LC3 punta within the …

Assessment Of Wind-Induced Response And Drivability Of The Confederation Bridge, Bilal Bakht

Digitized Theses

The Confederation Bridge is a 13 km long precast concrete structure, constructed between 1993 and 1997, comprised of 43 - 250 m spans in an alternating rigid frame/cantilevered drop-in span arrangement. Wind studies were conducted in the early '90s at the Boundary Layer Wind Tunnel Laboratory to predict the design wind speed and associated design wind loads for the bridge. The dynamic wind loads were developed using full-aeroelastic model test data for the first time. The bridge owners implemented a comprehensive bridge monitoring programme to document the interaction of the bridge with its environment by installing a complex instrumentation system …

Application Of Expanding Polyurethane Foam For Upgrading The Seismic Resistance Of Unreinforced Masonry Structures, Christopher Tyler George Ing

Digitized Theses

Unreinforced masonry (URM) constitutes a prevalent part of the modem building inventory and represents a major seismic risk. This study investigates the use of expanding polyurethane foam as a new technique to retrofit URM construction. Experimental tests of masonry assemblages have shown an increase in the shear capacity of up to five times and that the polymer core reduces tensile forces within the face shells under compression. Cyclic in-plane tests have shown that the load capacity of retrofitted wall panels are up to 2.5 times the strength of URM specimens and have demonstrated the potential for increased energy dissipation. An …

Control And Optimization Of Laminar Incompressible Fluid Flow, David Anthony Brown

Digitized Theses

The purpose of this thesis is to present a numerical algorithm for the dynamical opti­ mization of fluid flow systems that contain both geometric and control variables. This problem was formulated in an optimal control setting by specifying some performance functional to be minimized subject to the constraints provided by the discretized state equations. An algorithm was presented and applied successfully in the feedforward case to a simple fluid flow problem. Linear quadratic feedback control of laminar incompressible fluid was also studied with the eventual intention of incorporating feedback control into the optimization process. A feedback law was developed nu­ …

Children Exposed To Intimate Partner Violence And The Social Construction Of Gender: A Qualitative Secondary Feminist Analysis, Jennifer Rae Mcdonald

Digitized Theses

Little is known about constructions or enactments of gender among children exposed to intimate partner violence (IPV). The purpose of this study was to examine this phenomenon, from the perspectives of mothers. A qualitative secondary analysis with a feminist approach provided the theoretical and methodological underpinnings for the development of this research. Study participants consisted of mothers involved in a group program who were interviewed prior to and at the completion of the program. Codes and memos guided the analysis and development of thematic categories, revealing four major themes: Normalization and Silencing of the Violence, Parroting Responses to Violence, Undeniable …

Clinical Situations Of Uncertainty And Access To Resources: A Study Of Community Family Physicians, Linda Li-Wen Lee

Digitized Theses

Aims: To explore the situational factors that are present during moments of uncertainty

that lead family physicians to access external resources of varying type.

Methods: Situational cues were identified using self-observational journaling. A survey was then performed to study physicians' likelihood of accessing external resources in response to each situation.

Findings: Identified situational cues included case aspects such as unfamiliar or complex presentations, potentially serious conditions, failure of previous treatments, and the patient or others in attendance being perceived as anxious, demanding, distrustful or dissatisfied. In all situations, physicians reported greatest likelihood to refer to specialists. However, with conditions that …

Characterizing Prb’S Role In Cell Cycle Control, Mammary Gland Development, And Tumorigenesis: A Unique Connection To Tgf-P Signalling, Sarah Marie Francis

Digitized Theses

The ability to respond to anti-growth signals is critical to maintain tissue homeostasis and loss of this proliferative control mechanism is considered a hallmark of cancer. Negative growth regulation generally occurs during the G0/G1 phase of the cell cycle, yet the redundancy and complexity among components of this regulatory network have made it difficult to discern how negative growth cues protect cells from aberrant proliferation. .

Transforming growth factor (3(TGF-P) is a crucial mediator of mammary epithelial morphogenesis and can negatively regulate cell cycle progression. TGF-P has been shown to inhibit cyclin dependent kinase activity, which leads to activation of …

Best Practice In Speech-Language Pathology In Language And Cognitive-Communication Post Stroke, J. Ross Graham

Digitized Theses

Introduction: With 21% to 38% of individuals experiencing aphasia post stroke, language

and communication impairments are major issues for clinicians working with stroke patients. To identify, assess, and treat language and communication impairments, speech-language pathologists (SLPs) use a wide variety of tools and interventions. However, the degree to which common screening, assessment, and treatment practices are supported by the evidence is unclear.

Method: This study (1) examined the actual screening, assessment, and treatment practices of 435 SLPs (as part of a cross-Canada survey); (2) identified best practice (via the consensus opinions of a clinician focus group); and (3) compared actual …

Annexin A5 Inhibits Myocardial Inflammation And Improves Cardiac Function During Endotoxemia In Mice, Paul Arnold

Digitized Theses

Sepsis is a complex clinical syndrome that results from a harmful or damaging

host response to infection. Sepsis is characterized by the production of proinflammatory

cytokines like TNF-a and IL-ip, which have been shown to contribute to cardiovascular

dysfunction. Annexin A5 is a phospholipid binding protein that has been shown to have

anti-inflammatory, anti-apoptotic and anti-coagulant properties. However, its effect on

cardiac function during sepsis has not been established. This thesis investigated the

effect of annexin A5 on myocardial cytokine production and cardiac function during

endotoxemia in mice. It was found that annexin A5 treatment at the onset of

endotoxemia …

Analysis Of The Elastic Field In Functionally Graded Materials, Mohsen Mohammadi

Digitized Theses

In this thesis, the elastic field in circular beams and pipes made of functionally graded materials is considered. The following aspects are presented

First, the thermoelastic stress field in a functionally graded curved beam, where the elastic stiffness varies in the radial direction, is considered. An analytical solution is obtained where the radial variation of the stiffness is represented by a fairly general form. The stress fields corresponding to two different cases for the elastic properties are examined. The flexural stress in the curved beam is then compared with that of a ring. A relatively simple ap­ proximate solution is …

Characterization Of The Interaction Between Numb And The Anaplastic Lymphoma Kinase (Alk), Ran Wei

Digitized Theses

Originally identified as a cell fate determinant, Numb has been found to also act as an epithelial polarity protein, an adaptor, an endocytotic regulator and a tumor suppressor. Recently, anaplastic lymphoma kinase (ALK) was identified as a potential Numb-interacting protein in our lab. ALK is a receptor tyrosine kinase and is expressed mainly within the neonatal brain. Thus ALK likely plays an important role in development of the nervous system. In addition, mutated ALK is associated with a number of cancer cell lines and tumors. In this thesis, the interaction of Numb with ALK was confirmed and was found to …

Cortical Autonomic Alterations With Hypertension, Katelyn Norton

Digitized Theses

Objective: This study tested whether the medial prefrontal cortex (MPFC) is differentially involved in human cardiovagal control in normotensive (NT) versus hypertensive (HT) subjects.

Design: Functional magnetic resonance imaging was combined with measures of heart rate (HR) and baroreflex sensitivity (BRS) during a 30-sec static handgrip (HG; 30% maximal strength) task.

Results: Baseline HR was higher in HT (68±3 bpm) versus NT (59±2 bpm). Cardiovagal baroreflex sensitivity was lower in HT (6.8±1.7 msec/mniHg) versus NT (16.4±2.2 msec/mmHg). During HG, HR increased similarly in HT (2±1 bpm) and NT (4±1 bpm). In NT, the HR response was associated with deactivation in …

Anion Accelerated Semicarbazone Formation With Pyruvamide, Susanta Dan

Digitized Theses

Isophthalamide and pyridine dicarboxamide have been a common motif to anion receptor design. Dynamic combinatorial chemistry has been a fast growing field towards the advancement of receptor design through the use of labile bonds. Schiff bases have been employed as the labile bonding unit of recent receptors.

A pyridine dicarboxamide analogue containing a labile bond via a semicarbazone unit was synthesized from the condensation between a semicarbazide and a pyruvamide. Two semicarbazone receptors displayed preferential binding of chloride over other common anions tested (Br‘, HSO4", TsO', AcCT, H2PO4 ). It was observed that chloride accelerates the formation o f the …

Clinical Performance Target Attainment And Health-Related Quality Of Life In Southwestern Ontario In-Centre And Satellite-Based Hemodialysis Patients, Michael Jason Diamant

Digitized Theses

Dialyzing in community-based satellite hemodialysis units has been associated with higher patient satisfaction and diminished physical stress as compared to hospital- based in-centre units. A cross-sectional comparison of clinical performance target attainment and health-related quality of life between prevalent in-centre and satellite dialysis patients was conducted. All patients dialyzing at the London Health Sciences Centre and associated satellite units as of July 24, 2008 who met the eligibility criteria (n

= 522) were enrolled. Patient attainment of hemoglobin, albumin, calcium-phosphate product, Kt/V, and vascular access targets were compared. Participants were also administered the Kidney Disease Quality of Life Short-Form questionnaire. …

Construction Of A Recombination-Based Reporter System To Identify Gene Expression In Staphylococcus Aureus, Christopher P. Melo

Digitized Theses

Staphylococcus aureus harbours several iron acquisition systems, allowing for survival within the iron-restricted host environment. Five such systems have been identified in S. aureus; it is unknown why S. aureus maintains so many of these systems. Studies have shown that some iron transport proteins might be differentially expressed in different organs in vivo. The purpose of this study was to construct an in vivo expression technology (IVET) system to identify temporal expression patterns of S. aureus iron transport systems. An IVET utilizing the CrelloxP recombination system was constructed for use in S. aureus. Using genome-integrated and multi-copy ere constructs driven …

Combined Treatment Of Human Tumour Cells With Adenovirus Dl1520 And Melphalan As A Strategy To Enhance Cancer Therapy, Alexander Sykelyk

Digitized Theses

Oncolytic adenoviruses exploit tumour-specific properties to selectively kill tumor cells. Anti-tumour effects of combined treatment with adenovirus dll 520 (selective for p53-deficient cells) and chemotherapy are well documented. It was hypothesized that combined treatment of dll 520 and melphalan would be more effective than established dh 520-chemotherapy combinations. Colourimetric- based cell viability assays and flow cytometric analysis of cell death were used to assess anti-tumour effects of combined treatments. Melphalan-mediated changes in coxsackievirus and adenovirus receptor (CAR) mRNA and protein levels were assessed using RT-PCR and immunoblot, respectively. Melphalan enhanced the anti-proliferative effects of dll 520 better than cisplatin and …

Connexin36 Is A Negative Regulator Of Differentiation In Human Neuroblastoma Cells, Mandeep Sidhu

Digitized Theses

Gap junction channels permit intercellular communication through the passage of small molecules and metabolites between adjacent cells and are involved in regulating cellular processes such as homeostasis, differentiation, and proliferation. Connexins (Cx) are the constituent proteins of gap junctions and the neuronal connexin, Cx36, is highly expressed in the developing nervous system. In the present study, the effect of Cx36 on differentiation was investigated by manipulating Cx36 expression levels and inducing differentiation of SH-SY5Y cells. Following retinoic acid induced differentiation of SH- SY5Y cells, Cx36 mRNA expression increased, while Cx45 mRNA expression was unaffected. Cx36 overexpression resulted in diminished retinoic …

Do Brown-Headed Cowbirds Skew Host Offspring Sex Ratios Because They Are Large?, Robert Peter Decaire

Digitized Theses

Brood parasitism of song sparrow (Melospiza melodia) nests by brown-headed cowbirds (Molothrus ater) leads to a 50% reduction in the number of female offspring that survive to day 6 post-hatch and to fledging age. It has been proposed that this effect can be explained by size-based competition. The cowbird is larger than male sparrow nestlings, which are in turn larger than females. It is thought that the females cannot compete successfully against these two larger classes of nestling competitors, and suffer higher rates of mortality as a result. I tested this hypothesis by adding a large conspecific nestling to just-hatched …

Diabetes And Technology For Increased Activity (Data), Emily Alicia Read

Digitized Theses

Physical inactivity is a primary target for prevention of cardiovascular disease and type 2 diabetes. Rural Canadians are at increased risk of metabolic syndrome - a clustering of risk factors preceding these conditions. This study investigated feasibility and effectiveness of a stage-matched physical activity intervention using novel self­ monitoring technologies in rural adults with metabolic syndrome. Adherence to self­ monitoring protocols was >94%. Stage of change increased by 1 stage (p=0.001). Physical activity increased from 5579 ± 1964 steps/day at week 1 to 7818 ± 4235 steps/day at week 8 (p=0.02). V02max increased by 17% (p<0.05). BMI decreased from 33.1 to 32.7 (p=0.016). Participants were comfortable using the technology, found it easy- to-use, of low burden, and perceived it positively. This pilot study shows that this stage- matched technology intervention for increased physical activity was feasible and effective in high-risk adults in rural Ontario.

Distinct Human Progenitor Subtypes Promote Islet Regeneration Via Activation Of Endogenous Angiogenic Or Neogenic Programs, Gillian Irina Bell

Digitized Theses

Transplanted murine bone marrow (BM) progenitor cells stimulate endogenous beta cell proliferation and insulin production. To enrich for analogous human progenitor cells, we purified human umbilical cord blood (UCB) and BM based on high aldehyde dehydrogenase activity (ALDHhl), a conserved function in multiple progenitor lineages. Transplantation of ALDHhl mixed progenitor cells or culture- expanded multipotent stromal cells (MSC) into streptozotocin-treated NOD/SCID mice revealed endogenous islet regeneration occurred via distinct mechanisms. Transplantation of ALDHhl cells improved systemic hyperglycemia via increased islet vascularization and proliferation resulting in increased islet size, but not islet number. Contrary to mixed-progenitor cells, transplantation of cultured MSC …

Depression In Nurses: A Secondary Data Analysis Of The National Survey Of The Work And Health Of Nurses, Marilyn Carol Ohler

Digitized Theses

Quality patient outcomes are reliant on the calibre of nursing, which in turn is a result of healthy work environments and practice settings. It is imperative during the current shortage of nurses that healthcare organizations retain these valued knowledge workers. The National Survey of the Work and Health of Nurses (NSWHN) 2005 examined a broad spectrum of nurses’ work and their health status, with one finding of particular concern. A higher rate of depression (1 in 10) exists in nurses compared to their counterparts in other national surveys. This secondary analysis of the NSWHN data focused therefore, on the outcome …

Daily Flight Timing And Movement Strategies Of Migrating Landbirds: Importance Of Local Wind Patterns, Bethany Gloria Thurber

Digitized Theses

Although weather variation is known to affect migratory behaviours of landbirds, the specific effects of winds on flight timing and orientation at ecological barriers are not well understand. To assess seasonal effects of winds on flight timing at Long Point, Ontario, I compared estimates of daily arrival and departure to nocturnal radar counts. Landfall occurred later on nights with unfavourable versus favourable winds, and later on nights in spring versus fall. Daily arrival was positively associated with radar counts on nights with NE and SW winds, but variably associated otherwise. Departure timing could not be assessed. To investigate effects of …

Dehydration And Adh-Induced Changes In Renal Stanniocalcin-1 Mrna Levels In The Rat, Olga Sazonova

Digitized Theses

STC-l is expressed in kidney collecting duct cells and targeted to most other nephron segments. However, its function and regulation are both unclear. The present study explored the regulation of Stc-1 mRNA levels in vivo in rat models of dehydration and overhydration. Dehydration caused an upregulation in Stc-1 mRNA levels in kidney cortex and to a lesser extent the inner medulla. Antidiuretic hormone was identified as a potential mediator of gene induction during dehydration acting through the V2 receptor. In contrast overhydration did not produce changes in renal gene activity. Histological studies revealed no difference in STC-1 receptor distribution along …