VictorJuiz/thesis huggingface dataset:
Translational Studies of Fatty Acid Ethyl Esters (FAEE) in Meconium and Hair as Biomarkers of Prenatal Ethanol Exposure Risk
Keywords: FAEE
FASD
Hair
Meconium
toxicology

The development of effective maternal and neonatal screening methods to identify individuals at risk for FASD is essential in addressing this substantially prevalent disorder. FAEE are non-oxidative ethanol metabolites validated as biomarkers of chronic ethanol exposure. This thesis presents a series of studies in animals and humans examining meconium and hair FAEE as measures of fetal exposure, population-health, and maternal ethanol use. Characteristics of meconium FAEE production were examined in guinea pig fetuses chronically exposed to a maternal ethanol dose of 4g/kg/day. Fetuses were sacrificed at three gestational ages (GD45, GD55, GD65) and evaluated for FAEE, hippocampal weight, and hepatic CYP2E1 activity. FAEE above 0.642 nmol/g was 96% sensitive and 100% specific in distinguishing ethanol-exposed fetuses from isocaloric-sucrose pair-fed controls (AUCROC = 0.999). FAEE correlated inversely with hippocampal weight at GD45 (rs = -0.943), GD55 (rs = -0.536) and GD65 (rs = -0.549). FAEE exhibited an inverse correlation with fetal hepatic CYP2E1 activity (rs = -0.799, p = 0.002), suggesting variability in CYP2E1 induction as a possible source of intra-litter variability in FAEE concentrations noted in this animal model and similar differences clinically observed in dizygotic twins. Performance of FAEE as a population screening tool was examined through collection of meconium from 93% of live PEI neonates over a one-year period (n=1307). This study, the first provincial incidence assessment of fetal ethanol exposure conducted in Canada; revealed a 3.1-4.4% incidence, 3-to-4 fold higher than estimates locally reported by the PEI Reproductive Care database. Performance of hair FAEE as a measure of maternal ethanol use was evaluated through examination of FAEE-positive hair samples from 199 female and 73 male subjects. Risk of false-positivity through use of ethanol-containing hair products was identified, however no population-level tendency towards higher FAEE in females was observed. Females exhibited lower concentrations of EtG, an alternative biomarker of consumption. FAEE EtG concordance was higher in males (69.9% vs. 36.2%), with evidence of EtG false-negativity in 26% of individuals with discordant results (n=111). These findings suggest that combined analysis of FAEE and EtG is optimal when assessing a female population through hair analysis.
A Phenomenological Approach to Comparison: The Non-Metaphorical Poetics of Paul Celan and Wang Wei
Keywords: Comparison
German Postwar Poetry
Paul Celan
Phenomenology
Táng Poetry
Wang Wei

AbstractThis dissertation explores the grounds of comparison, and what makes comparison meaningful, through an encounter between Paul Celan (1920-1970), the pre-eminent post-war poet of the German language, and Wáng Wéi (701-761), one of the master poets of the Táng Dynasty when classical Chinese poetry was at its peak. A traditional approach to comparison would seek to establish certain "common denominators" by applying pre-given historical, cultural or linguistic influences as commensurable categories of analysis. However, the aesthetic qualities of both Celan's and Wáng Wéi's poems resist reduction to categories in common and thus defies the very notion of commensurability. I have instead employed insights from the phenomenological tradition - ranging from Husserl to Heidegger, Gadamer and Merleau-Ponty - to illuminate the complexity of the poets' similar positions, specifically their non-metaphorical poetics, resulting in contrapuntal dialogues between different ideas and expressions that are grounded in their respective cultural background. Developing from Husserl's "transcendental inter-subjectivity", my approach in particular applies Merleau-Ponty's phenomenology of body to comparison.I, therefore, pursue three phenomenological concepts derived from Celan's poetics: Begegnung (Encounter), Ort (Site), and Licht (Light). Begegnung calls for an immanent alterity that formulates the condition of comparison; Ort indicates the site of Begegnung i.e. its context and circumstances, and Licht illuminates the consequences. Establishing counterparts from Chinese literary aesthetics in a dialogical analysis, I examine the poets' deep affinities in their poetic landscapes. Despite the separation of these literary works across epochs, continents and cultures, comparison in a phenomenological paradigm allows us to see more about these works than if they were regarded in isolation. As comparison and translation are intricately related, I include multiple translations and conclude with a discussion of how my phenomenological approach to comparison can be applied to the practice of translation as well.
Vibrationally-fluidized Granular Flows: Impact and Bulk Velocity Measurements Compared with Discrete Element and Continuum Models
Keywords: Continuum Modeling
Discrete Element Modeling
Fluidization
Granular Flows
Local Impact Behavior
Vibrationally-Fluidized Flows

A new laser displacement probe was developed to measure the impact velocities of particles within vibrationally-fluidized beds. The sensor output was also used to measure bulk flow velocity along the probe window and to provide a measure of the media packing. The displacement signals from the laser sensors were analyzed to obtain the probability distribution functions of the impact velocity of the particles. The impact velocity was affected by the orientation of the laser probe relative to the bulk flow velocity, and the density and elastic properties of the granular media. The impact velocities of the particles were largely independent of their bulk flow speed and packing density. Both the local impact and bulk flow velocities within a tub vibratory finisher were predicted using discrete element modelling (DEM) and compared to the measured values for spherical steel media. It was observed that the impact and bulk flow velocities were relatively insensitive to uncertainties in the contact coefficients of friction and restitution. It was concluded that the predicted impact and bulk flow velocities were dependent on the number of layers in the model. Consequently, the final DE model mimicked the key aspects of the experimental setup, including the submerged laser sensor. The DE method predictions of both impact velocity and bulk flow velocity were in reasonable agreement with the experimental measurements, with maximum differences of 20% and 30%, respectively. Discrete element modeling of granular flows is effective, but requires large numerical models. In an effort to reduce computational effort, this work presents a finite element (FE) continuum model of a vibrationally-fluidized granular flow. The constitutive equations governing the continuum model were calibrated using the discrete element method (DEM). The bulk flow behavior of the equivalent continuum media was then studied using both Lagrangian and Eulerian FE formulations. The bulk flow velocities predicted by the Lagrangian approach were in good agreement with those obtained using DEM simulations over a wide range of tub wall amplitudes. The local impact velocity distribution predicted by the DEM was also compared to the continuum model using the shear rate as a measure of the granular temperature.
Three Essays on Vertical Organization and Firm Strategy
Keywords: Contracts
Firm boundaries
Firm strategy
Supply arrangements
Vertical integration
Vertical organization

My dissertation encompasses three essays exploring the interplay between vertical organization and firm strategy.The first study explores how a firm's market position shapes the design of vertical arrangements with suppliers. I develop a simple model showing that differentiated market positions increase quasi-rents in the face of supply hazards. As a consequence, firms competing from more differentiated market positions are also more willing to invest in contractual safeguards to mitigate these hazards. Analysis of trading relationships in the Costa Rican coffee industry provides strong empirical support for the main arguments. The findings also suggest that a complete understanding of contract duration and price premiums in supply relationships requires the integration of economizing and strategizing perspectives. The second study turns to the implications of discrete forms of organization. In particular, this essay examines how vertical integration and geographic location affect a firm's ability to adapt to a severe demand shock. Drawing on a rich dataset of manufacturing firms in Spain, I show that while vertically-integrated firms performed better in `steady state,' they suffered greater declines in the aftermath of the crisis. I also show that the performance difference is increasing in the level of agglomeration economies. These results thus highlight the interaction between organizational scope and location characteristics in determining firm performance outcomes.The third study examines the connection between firm scope and geography in greater detail, looking at the extent to which vertical integration affects a firm's propensity to locate in dense industrial clusters. I argue that since greater vertical scope allows firms to be less dependent on location-based agglomeration economies, more vertically-integrated firms are less likely to choose dense industrial clusters as their production sites. I provide empirical support through analysis of a rich dataset of manufacturing plants established in Mexico by U.S. firms. This study thus provides important new evidence on how vertical scope decisions can shape subsequent strategic choices and, ultimately, firm performance.
Nonlinear Optics at the Single-photon Level
Keywords: Cross-phase modulation
Light-matter interaction
Nonlinear Optics
Quantum Information Processing
Quantum Optics
Weak-value amplification

In this thesis I report the first experimental observation of an interaction between a postselected single photon and an electromagnetic field containing a few thousand photons.This is the first observation of the nonlinear interactions due to a single freely propagatingphoton. To achieve this pioneering result, we have theoretically and experimentally studied nonlinear optics at the few-photon level. To the best of our knowledge, the pulse energy levels used for our experiments are the lowest energies used for cross-phase modulation in free space.Photon-photon interaction is vanishingly weak; the strength of this interaction can be enhanced in the presence of a material medium as mediator. In our experiment, we use an atomic coherence effect, namely Electromagnetically-induced Transparency (EIT), to produce a `giant' nonlinear interaction between two optical fields. We have observed a nonlinear phase shift of 18 ± 4 µrad per freely propagating single photon. This is done by sending very weak coherent state pulses into the medium and subsequently detecting single photons, inferring the existence of a photon in the interaction region.The optical setup, electronics and software that have been developed during the completion of this thesis provide the basis for several exciting future light-matter interaction experiments. We have produced phase-stable laser beams to create EIT in our cold Rubidium sample prepared in a Magneto-optical Trap (MOT). The laser system and the improved MOT setup have been built to be stable so that we can do very long data acquisition runs. We also have develop ed to ols and software with high precision and stability such that we can measure phase shifts down to micro-radian level.
Trajectories of Emotional Problems in an Ethnically Diverse Sample of Immigrants
Keywords: Ethnicity
Immigrant
Mental Health

The purpose of this dissertation was to examine mental health trajectories in immigrants living in Canada. The first study examined the rates of emotional problems among parents, versus non-parents, using all three waves of data from a sample of immigrants in Canada (N = 7055). After controlling for a variety of socio-demographic covariates, results from multilevel logistic regression models indicated that immigrant parents have higher odds of reporting emotional problems in comparison to non-parent immigrants, and these differences are stable across the first four years following immigration. These effects were evident after ethnicity was included in the model and after controlling for relevant socio-demographic characteristics, such as age, gender, socioeconomic status, and immigrant category, suggesting an effect of caregiver strain. In terms of ethnic differences, Black, Arab, South Asian and East Asian respondents have emotional problems that increase at a faster rate in comparison to White immigrants over time. Results revealed that immigrants that endorsed being divorced without children are also particularly vulnerable. The second study examined depressive symptoms in a sample of mothers who were evaluated closely after the birth of a baby using four waves of data from the Kids Families and Places study. Results from latent growth curve models indicated that immigrant mothers showed significantly more depressive symptoms in comparison to Canadian born mothers. More specifically, Asian immigrants and Black immigrants were found to have higher levels of depressive symptoms in comparison to White Canadian mothers. It was found that socioeconomic indicators were among the best predictors of maternal depression in Asian immigrant and Black immigrant mothers. The overall goal of this dissertation is to highlight the importance of studying immigrants, as there are a number of stressors and challenges associated with immigration, which may lead to increased rates of mental health problems. These challenges may be even more burdensome for immigrants who must care for economically dependent children.
Interface Properties of the Amorphous Silicon/Crystalline Silicon Heterojunction photovoltaic cell
Keywords: amorphous silicon
crystalline silicon
heterojunction
passivation
photocarrier radiometry
photovoltaics

Amorphous-crystalline silicon (a-Si:H/c-Si) heterojunctions have the potential of being a very high efficiency silicon photovoltaic platform technology with accompanying cost and energy budget reductions. In this research a heterojunction cell structure based on a-Si:H deposited using a DC saddle field plasma enhanced vapour deposition (DCSF PECVD) technique is studied, and the a-Si:H/c-Si and indium tin oxide/a-Si:H interfaces are examined using several characterization methods.Photocarrier radiometry (PCR) is used for the first time to probe the a-Si:H/c-Si junction. PCR is demonstrated as a carrier lifetime measurement technique - specifically, confirming carrier lifetimes above 1 ms for 1-5 Ohm.cm phosphorous-doped c-Si wafers passivated on both sides with 30 nm of i-a-Si:H. PCR is also used to determine surface recombination velocity and mobility, and to probe recombination at the a-Si:H/c-Si interface, distinguishing interface recombination from recombination within the a-Si:H layer or at the a-Si:H surface.A complementary technique, lateral conductivity is applied over a temperature range of 140 K to 430 K to construct energy band diagrams of a-Si:H/c-Si junctions. Boron doped a-Si:H films on glass are shown to have activation energies of 0.3 to 0.35 eV, tuneable by adjusting the diborane to silane gas ratio during deposition. Heterojunction samples show evidence of a strong hole inversion layer and a valence band offset of approximately 0.4 eV; carrier concentration in the inversion layer is reduced in p-a-Si:H/i-a-Si:H/c-Si structures as intrinsic layer thickness increases, while carrier lifetime is increased.The indium tin oxide/amorphous silicon interface is also examined. Optimal ITO films were prepared with a sheet resistance of 17.3 Ohm/square and AM1.5 averaged transmittance of 92.1%., for a film thickness of approximately 85 nm, using temperatures below 200 degrees celcius. Two different heat treatments are found to cause crystallization of ITO and to change the properties of the underlying a-Si:H film.Finally, an open circuit voltage of 699 mV was achieved using DCSF PECVD in the tetrode configuration to fabricate a metal/ITO/p-a-Si:H/i-a-Si:H/n-c-Si/i-a-Si:H/n+-a-Si:H/metal photovoltaic cell on a texturized wafer. The 4 cm2 cell had an efficiency of 16.5%, a short circuit current of 36.4 mA/cm2 and a fill factor of 64.7%.
Essays on Market Conditions and Corporate Investment Decisions
Keywords: Corporate Fiannce
Corporate Investment
Financial Regulations
Investment Allocation
Investor Belief Dispersion
M

This thesis investigates how market conditions -- different beliefs about firm value, the business cycle, and financial regulations -- affect corporate investment decisions in firms, and the impact of these decisions on corporate performance. In Chapter 1, I document evidence that belief dispersion affects corporate investment allocation. When investors disagree with each other on expectations about future project returns, firms allocate a larger share of total investment in riskier projects (for example, R and M), in order to exploit the disagreement, and they allocate less in physical capital investment. This effect becomes amplified when firms experience a positive return shock to CAPX, when more investment in CAPX would be expected. To establish causality, I use mergers between brokerage houses to provide a source of exogenous shocks to belief dispersion. Chapter 2, written jointly with Mohammad Rahaman, uses economic recessions as settings for `creative destruction' and examines the efficiency of pro-cyclical capital reallocation through the corporate-control market. It shows that the efficacy of M investment activities varies with time and in intensity, as firms that concentrate most of their M activities in the good times are more likely to exit inefficiently in a subsequent recession. The results suggest that firms misallocate capital through excessive M\ during expansions, thus becoming more vulnerable when there is a negative aggregate shock. Chapter 3, written jointly with Varouj Aivazian and Mohammad Rahaman, provides cross-country evidence to show that adverse financial shocks to firms can be attenuated through regulations. Episodes of systemic banking crises across many countries are examined to identify unanticipated credit contractions; firm investment growth during and post crisis periods are compared to their pre-crisis levels. The chapter shows that credit contractions are costly for firms, and that they are more costly for firms that are more reliant on the external capital market. It is also shown that declines in investment growth are greater for externally dependent firms if such firms are embedded in ex-ante ``repressively" regulated financial markets. The results suggest that specific financial reforms play a significant role in attenuating the propagation of a banking crisis to the real sector.
Diverging and Contested Feminisms in Early Social Work History in Ontario (1900-1950)
Keywords: Canadian history
Canadian social work
feminist history
imperialism
postcolonial feminist history
socialist feminism

AbstractThis study examines early Ontario social work history by documenting the lives of four women who contributed to the history of Ontario social work some of whom have largely been forgotten. While social work remains a female-dominated profession, both currently and historically, few historical studies have addressed this. This study attempts to equalize the views and voices of social workers by including select women who were active in the field illuminating and identifying some of the contributions of women to the debates which characterized early social work in Ontario. This study selected two women from the radical tradition with socialist/communist affiliations and as counterpoint two figures who were members of the Imperial Order of the Daughters of the Empire and who represent a conservative value system based in the tradition of British imperialism. Three guiding research questions for the study are 1) what conditions organizations and practices shaped and positioned social work as a profession in its formative years 2) how were the significant debates/discursive trajectories reflected in the organizational settings of early social work? 3) How were these ideas implicated in their practice? Did these women speak through the organizations they led or participated in? How did they contribute to the production of or alternative positions to, the competing epistemĂŠs of the time? This research provides an original contribution by elaborating a history of ideas in social work through the prism of organizational practice and key formative figures. By adopting this dual focus, I capture individual agency in life history but also the cultural shift of discourse and regimes of truth, not only within individual lives but also as a myriad of intersecting overlapping discursive (ideas) and material (practices) occurrences.
MicroRNAs in the Regulation of Cellular Stress Responses
Keywords: Cancer
Chemotherapy
Homeostasis
Metastasis
microRNA
Stress

MicroRNAs are key regulators of cellular functions at post-transcriptional level. There is an emerging concept that microRNAs are involved in the regulation of how cells respond to changes in environment and stress conditions. Understanding the consequence of microRNA regulatory network has the potential to answer a multitude of fundamental questions. Dysregulation of these processes is associated with cancer development and drug resistance. In this dissertation, four studies are presented. The first study demonstrated that microRNA-17 targets both oncogene MDM2 and tumor suppressor gene PTEN: it suppresses glioblastoma tumor cell proliferation in favorable condition. However, when challenged by starvation or chemotherapy, it induced angiogenesis and the generation of tumor stem-like cells, and helping tumor cells survive in metabolic stress. The second study revealed the role of microRNA-17 in the regulation of chemotherapy sensitivity. By analyzing tissue samples from colorectal cancer patients, we found that microRNA-17 serves as a predictive factor of chemotherapy and prognostic factor of overall survival. Overexpression of microRNA-17 in colorectal cancer cells increased drug resistance and cell motility. The third study focused on the impact of microRNA on antitumor immune response. We found vigorous anti-melanoma immune response in microRNA-17 transgenic mice, which is characterized by CD8+ T lymphocytes infiltration. We further demonstrated the potential role of microRNA in the coordination of interaction between tumor cells and microenvironment. The fourth study examined the function of microRNA in tissue regeneration. We found an enhanced wound healing process in anti-microRNA-378 transgenic mice that have otherwise normal phenotype. Knocking down microRNA increased the expression of its targets Vimentin and Integrin beta-3, helping wound healing. Conjugated gold nanoparticle treatment delivered antisense oligos to the wound area and achieved therapeutic effect. Taken together, these studies illustrate the multiplicity of microRNA in the coordination of cellular stress responses.