VictorJuiz/thesis huggingface dataset:
Challenging the Behavioural Model: Exploring Individual, Interpersonal, and Structural Predictors of Adolescent Dual Protection Use

The optimal model to support adolescent sexual health is the concurrent use of hormonal birth control and condoms. This dual protection approach prioritizes protection against unplanned pregnancy as well as sexually transmitted diseases (STDs) and human immunodeficiency virus (HIV). In order to explore individual, interpersonal and structural factors that influence adolescent protection use, multivariate Chi-squared Automatic Interaction Detector (CHAID) analysis was completed with a national sample of adolescents (n=2320) from the 2002 Canadian Youth, Sexual Health, and HIV/AIDS Study. CHAID is a decision tree method which assesses interactions between significant independent variables to optimize prediction of the dependent variable (i.e. safer-sex protection method). Among adolescent females, the following factors were associated with dual protection use: high condom intentions; having lived with both biological parents; having accessed a medical professional or media as the primary source of HIV/AIDS information; having utilized a medical professional as the primary source of sexual health information; having never had unwanted sex; having not consumed alcohol and/or drugs before sex; frequent sexual activity; having identified a medical professional as the primary source of STD advice; having been tested for STDs; and having supported the importance of talking about condoms with a partner. Among adolescent males, dual protection was associated with: high condom intentions; frequent sexual activity; the belief that both partners are responsible for condom use; having been born in Canada; having noted uncertain or high levels of religiosity; having been older than 14 at first sexual intercourse; having been able to speak with their father about sex; having accessed a medical professional or media as the primary source of HIV/AIDS information; and having reported a peer group that did not use tobacco. The results indicate that structural factors, in concert with individual and interpersonal factors, play a vital role in understanding adolescent safer-sex practices. Policy and practice implications include revisions to sexual health curricula, sexual health service accessibility for all adolescents, and targeted prevention programming for adolescents at highest risk. Further research into the sexual health of male adolescents and the influence of structural factors on sexual health among diverse samples should be prioritized.

Keywords: Adolescent Health
Sexual Health
Advisor: Fuller-Thomson, Esme
Heraldry in the Trecento Madrigal

This study investigates a repertoire of eighteen madrigals whose texts refer to heraldry, all of which were composed in trecento Italy. The hereditary and personal arms cited in the song texts are those of the Visconti, Della Scala and Carrara families of northern Italy. Though these madrigals have been used in the past as a means for dating manuscripts and reconstructing composer biographies, they have never been studied as a discrete repertoire. This study applies musicological, heraldic and art historical approaches to the repertoire in order to investigate the heraldic madrigal as a manifestation of political authority in trecento Italy. Part One offers background information necessary to the understanding of the heraldic madrigal repertoire. Chapter 1 presents a glossary of heraldic terminology, and an overview of the role of heraldry in late medieval life, art and literature, focusing on heraldry as a means of representing ideas of authority and identity in the late Middle Ages. Chapter 2 defines the heraldic madrigal and discusses the stylistic features unique to this repertoire. This chapter also considers the heraldic madrigal in the context of contemporary musical repertoires such as the Italian motet and the songs of the French ars subtilior. Chapter 3 presents a critical edition of heraldic madrigal texts with translations. Part Two consists of case studies. Chapter 4 explores the link between Jacopo da Bologna’s madrigal Aquila altera and the references to the Holy Trinity in the heraldry of its dedicatees, Giangaleazzo Visconti and Isabelle de Valois. Chapter 5 offers a re-evaluation of the poem La fiera testa, challenging the common opinion that the text is condemnatory. Chapter 6 considers non-musical models for the the madrigal texts Inperiale sedendo and Per quella strada, based on manuscripts owned by and dedicated to the Carrara family. The Conclusion of this study touches briefly on the legacy of the heraldic madrigal, giving a summary of later Italian songs containing references to the heraldry of noble families, such as the Malatesta and Medici.

Keywords: medieval music
heraldry
Italy
Advisor: Haines, John Dickinson
Marketing Institutions of Afforestation Generated Carbon Offsets in Canada: Political Sustainability, Ideology and the New Institutional Economics

Anthropogenically forced climate change has emerged as one of the most important, and polarizing, issues of our time. Afforestation generated carbon offset projects hold a position in Canada as potentially influential, yet frustratingly under-utilized, options to mitigate climate change. This dissertation responds to the question, “what are the economic implications of afforestation generated carbon offset institutions in Canada – and how appropriate are the tools of the New Institutional Economics (NIE) in their identification?” I establish the context for discussion by arguing that the NIE, as practiced, seems incapable of providing rigorous analysis while simultaneously responding to questions of power and distribution. The case of afforestation generated carbon offset marketing is presented as an appropriate context for exploring this point. A literature review is then used to establish general patterns regarding aggregating institutions for offset production and marketing, and aggregating institutions are presented as a response to the effects of transaction costs on the Canadian offset market. I then develop supply and demand curves to describe the equilibrium state of the Canadian offset market, into which the transaction costs borne by three aggregators are integrated. Their performance in fulfilling various policy objectives is evaluated. The results indicate that the primary variation between scenarios is the distribution of benefits. This focus on the distribution of benefits continues through demonstrating how subtle variations in modeling coefficients affect the regional distribution of afforestation projects within Canada, identifying the power associated with policy maker ideology. The role of policy maker ideology is then explicitly examined through a survey of government analysts and technicians and the application of discriminant analysis. The primary axes of afforestation ideology are identified, and demonstrated to be independent of concerns of transaction costs and aggregation. These results are integrated to argue that distributional concerns, particularly when ideologies are active in informing policy maker preferences, are critical to achieving sustainable policy outcomes, and that the NIE can respond to such concerns, but only if reform takes place to legitimate these techniques as part of the standard economic discourse.

Keywords: afforestation
new institutional economics
policy
ideology
carbon offset
Advisor: Smith, Tat
The Impact of GB Virus C co-infection on Mother to Child transmission of Human Immunodeficiency Virus

GB virus C (GBV-C) is a common, apathogenic virus that can inhibit human immunodeficiency virus (HIV) replication in vitro. Persistent coinfection with GBV-C has been associated with improved survival among HIV-infected adults while loss of GBV-C viremia has been associated with poor survival. If GBV-C does inhibit HIV replication, it is possible that GBV-C infection may reduce mother-to-child-transmission (MTCT) of HIV. This study investigated whether maternal or infant GBV-C infection was associated with reduced MTCT of HIV infection. The study population consisted of 1,783 pregnant women from three Bangkok perinatal HIV transmission studies (1992-94, 1996-7, 1999-2004). We tested plasma collected at delivery for GBV-C RNA, GBV-C antibody, and GBV-C viral genotype. If maternal GBV-C RNA was detected, the four- or six-month infant specimen was tested for GBV-C RNA. Rates of MTCT of HIV in GBV-C-infected and GBV-C-uninfected women and infants were compared using multiple logistic regression as were associations with MTCT of GBV-C and prevalence of GBV-C infection. The prevalence of GBV-C infection (i.e. presence of RNA or antibody) was 33% among HIV-infected women and 15% among HIV-uninfected women. Forty-one percent of GBV-C-RNA-positive women transmitted GBV-C to their infants. Only two of 101 (2.0%) GBV-C-RNA-positive infants acquired HIV infection compared to 162 (13.2%) of 1,232 of GBV-C-RNA-negative infants (RR 0.15, p<0.0001). This association remained after adjustment for maternal HIV viral load, antiretroviral prophylaxis, CD4+ count and other covariates. MTCT of HIV was not associated with presence of maternal GBV-C RNA or maternal GBV-C antibody. Maternal receipt of antiretroviral therapy was associated with increased MTCT of GBV-C, as was high GBV-C viral load, vaginal delivery and absence of infant HIV infection. GBV-C infection among women was independently associated with more than one lifetime sexual partner, intravenous drug use and HIV-infection. We observed a higher prevalence of GBV-C infection among HIV-infected compared to HIV-uninfected pregnant women in Thailand, likely due to common risk factors. Antiretroviral therapy appears to increase MTCT of GBV-C. Infant GBV-C acquisition, but not maternal GBV-C infection, was significantly associated with reduced MTCT of HIV. Mechanisms for these later two associations are unknown.

Keywords: HIV
GBV-C
vertical transmission
mother-to-child
Thailand
perinatal
Advisor: Remis, Robert S.
Millson, Margaret
Oxygen Regulation of Vascular Smooth Muscle Cell Proliferation and Survival

Arterial smooth muscle cells (SMCs) from the systemic and pulmonary circulations experience a broad range of oxygen concentrations under physiological conditions. The hypoxic response, however, has been inconsistent, with both enhanced proliferation and growth arrest being reported. This variability precludes a definitive conclusion regarding the role of oxygen tension in arterial disease. In the first part of this study, we determined if hypoxia elicits different proliferative and apoptotic responses in human aortic SMCs (HASMCs) incubated under conditions which do or do not result in cellular ATP depletion and whether these effects are relevant to vascular remodeling in vivo. Gene expression profiling was used to identify potential regulatory pathways. In HASMCs incubated at 3% O2, proliferation and progression through G1/S interphase are enhanced. Incubation at 1% O2 reduced proliferation, delayed G1/S transition, increased apoptosis and cellular ATP levels were reduced. In aorta and mesenteric artery from hypoxia exposed rats, both proliferation and apoptosis are increased after 48hrs. p53 and p21expression is differentially affected in HASMCs incubated at 1% and 3% O2. Hypoxia induces a state of enhanced cell turnover, conferring the ability to remodel the vasculature in response to changing tissue metabolic needs while avoiding the accumulation of mutations that may lead to malignant transformation or abnormal vascular structure formation. A unifying hypothesis in which events at the G1/S transition and apoptosis activation are coordinated by effects on p53, p21, their downstream effector genes and regulatory factors is proposed. Differences in the contractile responses of systemic and pulmonary arterial smooth muscle cells to hypoxia are well studied. Differences in proliferation and survival are anticipated because of differences in embryonal cell origin, oxygen concentrations within their respective microenvironments and in cellular energetics but these responses have not been directly compared. In the second part of the study, human pulmonary arterial SMCs (HPASMCs) proliferated at oxygen concentrations which inhibited cell growth in HASMCs. HPASMCs survived and maintained their intracellular ATP levels at levels of hypoxia sufficient to deplete ATP and induce apoptosis in HASMCs. In vivo studies in rats show proliferation and apoptosis in main or branch PASMCs only after 7 days of hypoxia. VSMCs are able to proliferate under hypoxic conditions as long as cellular ATP levels are maintained. HPASMCs have an enhanced capacity to maintain cellular energy status compared to HASMCs and hence their viability is preserved and the proliferative response predominates at lower oxygen concentrations.

Keywords: vascular hypoxia
smooth muscle cell proliferation
Advisor: Ward, Miachel E.
Role of Bacterial Effectors SopD and SopB in Pathogenicity of Salmonella enterica serovar Typhimurium.

Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that has evolved to take advantage of the eukaryotic host cells it inhabits during infection. It uses bacterial effectors translocated into the host cell cytosol to manipulate host cell machinery and establish a replicative niche. In this thesis I study the function of two of these effectors, SopD and SopB, which have been shown to act cooperatively to induce phenotypes associated with gastroenteritis (fluid secretion and neutrophil influx into the intestinal lumen). In addition to promoting gastroenteritis, SopD has also been implicated in systemic and persistent infection of mice. Although recently implicated in invasion, the precise function of SopD has remained elusive. Here I show that SopD affects membrane dynamics during S. Typhimurium invasion of epithelial cells. SopD promotes membrane sealing and macropinosome formation, events that may have important consequences for efficiency of bacterial cell entry in vivo. Furthermore, we demonstrate that SopD is recruited to the invasion site membranes through the phosphatase activity of SopB, suggesting a mechanism for their cooperative action during induction of gastroenteritis. Unlike SopD, SopB has been a focus of intense research efforts and its role in invasion as a phosphoinositide phosphatase is well documented. However, we have observed that SopB also inhibits fusion of lysosomes with Salmonella-containing vacuoles (SCVs) following invasion. This ability depends on SopB-mediated reduction of negative membrane charge of the SCV during invasion by hydrolysis of the phosphoinositide PI(4,5)P2. Membrane charge alterations driven by SopB result in removal of Rab GTPases from the SCV that depend on electrostatic interactions for their targeting. Two of these Rabs, Rab23 and Rab35 were previously shown to promote phagosome-lysosome fusion. Therefore their removal from the SCV may promote SCV trafficking away from the degradative endocytic pathway of host cells. This represents a new mechanism by which an invasion associated effector controls SCV maturation. Together, this work advances our knowledge of the interaction between S. Typhimurium and its host. This research also suggests a new mechanism by which pathogens other than S. Typhimurium could promote their intracellular survival.

Keywords: Salmonella
type III secretion
SopD
SopB
SigD
phosphoinositide
phagolysosome fusion
macropinosome
membrane charge
host-pathogen interactions
bacterial invasion
Advisor: Brumell, John
An Investigation of the ca. 2.7 Ga Late Archean Magmatic Event (LAME) in the Superior Province using 1-D Thermal Modelling

The Late Archean Magmatic Event (LAME), ca. 2.7 Ga, was the greatest crustal addition event in Earth history. My focus is the Superior Province of Canada, where LAME occurred ca. 2.75 – 2.65 Ga. Mantle plumes impinged on the Abitibi subprovince, where ~ 16 km regional thickness of tonalite-trondhjemite-granodiorite (TTG) melt was produced. Granites (sensu stricto) were the last magmatic phase of LAME, with a Superior-wide regional thickness of ~ 1 – 3 km. Assuming a crustal source for both TTG and granites, I use 1-D thermal models to investigate the origin of TTG in the Abitibi subprovince and that of late granites in the Superior Province. Melting curves appropriate to the source of TTG and granites are used to determine the thickness of melt produced in the models. I show that the incorporation of upward melt transfer into a standard model of lower crustal melting may increase the amount of predicted melt by ~ 1/(1-f), where f denotes the fraction of melt that is on average being extracted from the source rocks. Partitioning of heat producing elements between melt and restite reduces the amount of melt produced, but the effect is secondary compared to the increase in melt production through upward melt transfer. For the Abitibi subprovince, I show that the emplacement of a single plume coupled with the emplacement of a 12-km-thick greenstone cover can generate a maximum of ~ 9-km-thickness of TTG melt. However, the emplacement of a series of plumes, each coupled with the emplacement of a 3-km-thick greenstone cover and a 10-km-thick sill results in ~ 20-km-thickness of TTG melt. My model incorporates delamination of restitic eclogite. Finally, I show that late granites in the Superior Province may have resulted from thickening of a crust that had been “pre-heated” during earlier arc activity and that prolonged granitic magmatism observed in some areas of the Superior Province may be explained by late underthrusting of fertile source rocks into deeper and hotter regions of the crust.

Keywords: 2700 Ma
2.7 Ga
thermal model
numerical model
Late Archean
Neoarchean
TTG
tonalite
LAME
Late Archean Magmatic Event
plume
mantle plume
Superior
Abitibi
Archean granite
melting
Archean lithosphere
heat production
greenstone
delamination
crustal thickening
crustal heating
Advisor: Robin, Pierre-Yves
Development of Automated Robotic Microassembly for Three-dimensional Microsystems

Robotic microassembly is a process to leverage intelligent micro-robotic technologies to manipulate and assemble three-dimensional complex micro-electromechanical systems (MEMS) from a set of simple-functional microparts or subsystems. As the development of micro and nano-technologies has progressed in recent years, complex and highly integrated micro-devices are required. Microassembly will certainly play an important role in the fabrication of the next generation of MEMS devices. This work provides advances in robotic microassembly of complex three-dimensional MEMS devices. The following key technologies in robotic microassembly are studied in this research: (i) the design of micro-fasteners with high accuracy, high mechanical strength, and reliable electrical connection, (ii) the development of a microassembly strategy that permits the manipulation of microparts with multiple degrees of freedom (DOFs) and high accuracy, (iii) fully automated microassembly based on computer vision, (iv) micro-force sensor design for microassembly. An adhesive mechanical micro-fastener is developed to assemble micro-devices. Hybrid microassembly strategy, which consists of pick-and-place and pushing-based manipulations, is employed to assemble three-dimensional micro-devices with high flexibility and high accuracy. Novel three-dimensional rotary MEMS mirrors have been successfully assembled using the proposed micro-fastener and manipulation strategy. Fully automatic pick-and-place microassembly is successfully developed based on visual servo control. A vision-based contact sensor is developed and applied to automatic micro-joining tasks. Experimental results show that automatic microassembly has achieved sub-micron accuracy, high efficiency, and high success rate. This work has provided an effective approach to construct the next generation of MEMS devices with high performance, high efficiency, and low cost.

Keywords: Microassembly
Micromanipulation
Micro-robotics
Automated control
Micro-electromechanical systems
Advisor: Celghorn, William L.
Mills, James
Efficient Simulation, Accurate Sensitivity Analysis and Reliable Parameter Estimation for Delay Differential Equations

Delay differential equations (DDEs) are a class of differential equations that have received considerable recent attention and been shown to model many real life problems, traditionally formulated as systems of ordinary differential equations (ODEs), more naturally and more accurately. Ideally a DDE modeling package should provide facilities for approximating the solution, performing a sensitivity analysis and estimating unknown parameters. In this thesis we propose new techniques for efficient simulation, accurate sensitivity analysis and reliable parameter estimation of DDEs. We propose a new framework for designing a delay differential equation (DDE) solver which works with any supplied initial value problem (IVP) solver that is based on a general linear method (GLM) and can provide dense output. This is done by treating a general DDE as a special example of a discontinuous IVP. We identify a precise process for the numerical techniques used when solving the implicit equations that arise on a time step, such as when the underlying IVP solver is implicit or the delay vanishes. We introduce an equation governing the dynamics of sensitivities for the most general system of parametric DDEs. Then, having a similar view as the simulation (DDEs as discontinuous ODEs), we introduce a formula for finding the size of jumps that appear at discontinuity points when the sensitivity equations are integrated. This leads to an algorithm which can compute sensitivities for various kind of parameters very accurately. We also develop an algorithm for reliable parameter identification of DDEs. We propose a method for adding extra constraints to the optimization problem, changing a possibly non-smooth optimization to a smooth problem. These constraints are effectively handled using information from the simulator and the sensitivity analyzer. Finally, we discuss the structure of our evolving modeling package DDEM. We present a process that has been used for incorporating existing codes to reduce the implementation time. We discuss the object-oriented paradigm as a way of having a manageable design with reusable and customizable components. The package is programmed in C++ and provides a user-friendly calling sequences. The numerical results are very encouraging and show the effectiveness of the techniques.

Keywords: Delay Differential Equations
Sensitivity Analysis
Parameter Estimation
Discontinuous Ordinary Differential Equations
Runge-Kutta Methods
Linear Multistep Methods
Advisor: Enright, Wayne
Two Theorems of Dye in the Almost Continuous Category

This thesis studies orbit equivalence in the almost continuous setting. Recently A. del Junco and A. Sahin obtained an almost continuous version of Dye’s theorem. They proved that any two ergodic measure-preserving homeomorphisms of Polish spaces are almost continuously orbit equivalent. One purpose of this thesis is to extend their result to all free actions of countable amenable groups. We also show that the cocycles associated with the constructed orbit equivalence are almost continuous. In the second part of the thesis we obtain an analogue of Dye’s reconstruction theorem for etale equivalence relations in the almost continuous setting. We introduce topological full groups of etale equivalence relations and show that if the topological full groups are isomorphic, then the equivalence relations are almost continuously orbit equivalent.

Keywords: orbit equivalence
ergodic theory
Advisor: Junco, Andres del