VictorJuiz/thesis huggingface dataset:
Essays on Dynamic Contracts: Microfoundation and Macroeconomic Implications

This thesis consists of three chapters pertaining to issues of long-term relationships in labour markets. In Chapter 1, I analyze a model of a two-period advice game. The decision maker chooses to retain or replace the advisor after the first period depending on the first period events. Even though the decision maker and the advisor have identical preferences, this potential replacement creates incentive for the advisor to avoid telling the truth. I show the condition under which the decision maker can find a random retention rule that induces a truthful report from the advisor, and I characterize an optimal retention rule that maximizes the decision maker's expected payoff. In Chapter 2, I propose a search theoretic model of optimal employment contract under repeated moral hazard. The model integrates two important attributes of the labour market: workers' work incentive on the job and their mobility in the labour market. Even though all workers and firms are ex ante homogeneous, these two factors jointly generate (1) wages and productivity that increase with worker's tenure and (2) endogenous dynamic heterogeneity of the labour productivity of the match. The interaction of these factors provides novel implications for wage dispersion, labour mobility, and the business cycle behaviour of macroeconomic variables. Lastly, in Chapter 3, I quantitatively assess wage dispersion and business cycle implications of the model developed in Chapter 2. In terms of wage dispersion, the model with on-the-job search with wage-tenure contracts seems to accommodate sizable frictional wage dispersion. The model, however, generates very small productivity difference among workers, and shows weak evidence that the productivity difference generated by the endogenous variations in incentives is responsible for frictional wage dispersion. In terms of business cycle implications, workers' endogenous effort choice first amplifies the effect of productivity shock on unemployment rate. Second, responses of workers to productivity shocks generate marked difference between the effects of temporary productivity shock and that of permanent shock. Third, the analysis shows the importance of the distributional effect on macroeconomic variables during the transitory periods after a shock.

Keywords: Macroeconomics
Dynamic Contracts
Incentives
Advisor: Shi, Shouyong
Data Processing Techniques on Modern Hardware Architectures

The last decade has been characterized by radical changes in the computing landscape. We have witnessed the advent of multi-core processors, flash-based storage systems and the proliferation of scale out architectures, such as map-reduce-based systems and massively parallel databases. Although data management systems have embraced modern hardware technologies to some extent, they have not realized their full potential. The goal of this thesis is two-fold. Primarily, it demonstrates the staggering potential for performance improvement offered by modern hardware architectures and, then, proposes how data management systems must alter in order to realize this potential. Additionally, this thesis demonstrates that utilizing modern hardware architectures is important both for performance and energy-efficiency. Towards this goal, we propose query processing and indexing techniques for chip multiprocessors and we analyze the trade-offs of executing complex database queries on modern processor technologies. Subsequently, we propose query processing methods tailored to flash-based storage systems. Finally, we analyze the power consumption of database systems and we reveal opportunities for improving their energy efficiency.

Keywords: novel hardware
query processing
chip multiprocessors
energy efficiency
flash storage
databases
Advisor: Koudas, Nick
Arginine Synthesis in Humans

Arginine synthesis is a complex, age-dependant process involving multiple precursors and enzymes, and the interorgan transfer of substrates. The objectives of this thesis were to elucidate arginine synthesis from enteral precursors in newborn infants and in healthy adults using stable isotope methodology. In the first, of four studies, I validated the use of a non-invasive methodology using urinary amino acids for stable isotope studies of arginine synthesis and demonstrated a known, but under-recognised, problem with D-amino acid contamination of tracers. Implementing chiral chromatography, this issue was further investigated using samples from previous studies in our laboratory with several different isotopes. I demonstrated the novel finding that the impact of D-amino acids is dependent on the tracer used, and also on the age of the subject. In the second study, I used a multi-tracer design to assess arginine synthesis from enteral proline or glutamate in healthy preterm infants. Labeled arginine (M+2), proline (M+1) and glutamate (M+3) were given enterally to fifteen stable, growing preterm infants (gestational age at birth 30-35 weeks) at 1-3 weeks’ postnatal age. I found only arginine synthesis from proline, with no synthesis from glutamate. I conclude that enteral proline is the major contributor to arginine synthesis in vivo in human preterm infants. In the third study, I measured arginine synthesis from enteral proline in adults. I have demonstrated that enteral proline contributes significantly, ~25%, to newly synthesised arginine. In the fourth study, I used two glutamine tracers, 1-13C and 2-15N, to determine if glutamine is a carbon or nitrogen donor for arginine. I showed that enteral glutamine contributes ~50% of the carbon skeleton for arginine and that the 2-15N tracer significantly overestimates arginine synthesis, with the labeled N being transferred through transamination from pyrroline-5-carboxylate (to ornithine, rather than directly from glutamate to pyrroline-5-carboxylate. In conclusion, proline is the sole precursor for arginine in human neonates and combines with glutamaine as the dietary precusor in adults. As a precussor for arginine, though, glutamine’s main role is in provision of nitrogen independent of the carbon skeleton.

Keywords: Amino acids
Advisor: Pencharz, Paul B.
Ball, Ron
The Role of Form-focused Instruction: Learner Investment in L2 Communication

The purpose of this study is to examine the role of form-focused instruction in relation to learner investment in second language (L2) communication and learning. Although positive effects of form-focused instruction have been reported in the instructed second language acquisition literature, most of this research has been conducted from a cognitive-interactionist perspective. Little attention has been paid to the social and cultural factors of form-focused instruction, including learner investment— a desire to learn a second/foreign language taking into consideration learners’ socially constructed identities (Norton-Peirce, 1995). Drawing on second language socialization theory (Duff, 2007) and using discursive practices (Young, 2009) as an analytic framework, this study examines how form-focused instruction influences learner investment in L2 communication in the classroom setting. Twenty-four high school students in Japan participated in a study, where two Japanese teachers of English team-taught four 50-minute lessons. Each lesson contained a 30-minute treatment period, which consisted of a 15-minute exclusively meaning-focused (MF) activity and a 15-minute form-focused (FF) activity that included attention to both form and meaning. By counter-balancing effects of tasks, target grammar features, and teachers, the study examined whether and how the same learners invested in L2 communication in similar or different ways during the two different types of activities. Data were collected through classroom observations, video-recorded classroom interactions, stimulated recalls, interviews, questionnaires, and diaries. The interactional data were analyzed quantitatively by comparing the frequency of turns and language-related episodes during FF and MF activities. The same interactional data were also analyzed qualitatively in relation to discursive practices and self-reported data. The results showed that the FF activities created contexts for learners to establish their identities as L2 learners leading to more engagement in L2 communication than in the MF activities. This suggests that FF activities create a social context that enables learners to communicate in the L2 with greater investment than in MF activities.

Keywords: Instruction
Investment
Form-Focused Instruction
Discursive Practice
Language Socialization
Second Language Learning
Communication
Grammar
EFL in Japan
Identity
Advisor: Spada, Nina
Sequence Determinants of In Vivo and Intrinsic Nucleosome Occupancy

The genomes of all eukaryotic organisms are packaged into chromatin, the fundamental unit of which is the nucleosome. Since the proposal of the nucleosome as the primary repeating unit of chromatin structure in 1974, it has become clear that the biological roles of nucleosomes extend far beyond simple DNA packaging and include virtually all processes involving the genome. Despite the integral roles of nucleosomes in many fundamental biological processes, the relative contributions of the cellular cues and sequence features that directly govern their arrangement on genomic DNA remain unclear. In this Thesis, I characterise the sequence preferences of nucleosomes using data sets derived from genome-wide studies. I describe the analysis of data derived from the first genome-wide map of in vivo nucleosome occupancy across a eukaryotic genome (in this case, the budding yeast, Saccharomyces cerevisiae). Using these data, I construct a sequence-based linear model of nucleosome occupancy that takes into account structural features of DNA (which correlate with simple base composition) as well as transcription factor (TF) binding site information, which has significant ability to predict nucleosome occupancy in vivo. I go on to test particular aspects of this model and show that genetic perturbation of TFs that the in vivo model deems important (Abf1, Reb1, and Rsc3) have the expected effects, an increase in nucleosome occupancy over their cognate binding sites as well as a reduction in transcription from the corresponding genes, suggesting that these factors are required for promoter function and definition. I also confirm that in vitro nucleosome occupancy correlates highly with sequence features important for nucleosome occupancy in vivo and go on to develop a simple model for nucleosome occupancy based solely on histone-DNA interactions. This model suggests that base composition (G+C content) is a dominant feature in determining intrinsic nucleosome occupancy. Finally, I apply a model of intrinsic nucleosome occupancy to the human genome and show that there is a fundamental difference in intrinsic nucleosome occupancy at regulatory regions across species. This finding illustrates a potential functional consequence of variation in base composition in eukaryotic genomes.

Keywords: nucleosomes
chromatin
gene regulation
transcription
transcription factors
genomics
computational biology
Advisor: Hughes, Timothy R.
Statistical Methods for Dating Collections of Historical Documents

The problem in this thesis was originally motivated by problems presented with documents of Early England Data Set (DEEDS). The central problem with these medieval documents is the lack of methods to assign accurate dates to those documents which bear no date. With the problems of the DEEDS documents in mind, we present two methods to impute missing features of texts. In the first method, we suggest a new class of metrics for measuring distances between texts. We then show how to combine the distances between the texts using statistical smoothing. This method can be adapted to settings where the features of the texts are ordered or unordered categoricals (as in the case of, for example, authorship assignment problems). In the second method, we estimate the probability of occurrences of words in texts using nonparametric regression techniques of local polynomial fitting with kernel weight to generalized linear models. We combine the estimated probability of occurrences of words of a text to estimate the probability of occurrence of a text as a function of its feature -- the feature in this case being the date in which the text is written. The application and results of our methods to the DEEDS documents are presented.

Keywords: Kernel
Dating Documents
Shingle
Correspondence distance
Smoothing
Generalized linear models
Logistics regression
Local polynomial regression
Advisor: Feuerverger, Andrey
Researching Class Consciousness: The Transgression of a Radical Educator Across Three Continents

This study addresses the topic of class consciousness and the radical educator. Using the theory of revolutionary critical pedagogy and Marxist humanism I examine the impact of formative experience and class consciousness on my own radical praxis across three continents. The methodology of auto/biography is used to interrogate my own life history. I excavate my own formative experience in Scotland, Canada and my radical praxis as a human rights educator in Ghana West Africa. The study is particularly interested in the possibility of a radical educator transgressing across race, whiteness and gender while working in Ghana, West Africa. Chapter One begins by discussing the theory of revolutionary critical pedagogy, Marxist humanism and theories of the self. Chapter Two assesses the methodology of auto/biography,research methods and an introduction to formative experience. Chapter Three, Four and Five contain excavation sites from Scotland, Canada and Ghana with accompanying analysis. Chapter Six concludes with a summary of research findings.

Keywords: radical education
working class consciousness
formative experience
revolutionary critical pedagogy
popular education
popular theatre
sociological auto/biography
critical human rights
arts based education
Ghana
Scotland
collective self
ontology/epistemology
anti-racism
critical consciousness
oral history
gender and class
communist/socialist parties
auto-ethnography
ideology of educator
mining communities and unionism
organic intellectuals
Advisor: Goldstein, Tara
Applications of Lexicographic Breadth-first Search to Modular Decomposition, Split Decomposition, and Circle Graphs

This thesis presents the first sub-quadratic circle graph recognition algorithm, and develops improved algorithms for two important hierarchical decomposition schemes: modular decomposition and split decomposition. The modular decomposition algorithm results from unifying two different approaches previously employed to solve the problem: divide-and-conquer and factorizing permutations. It runs in linear-time, and is straightforward in its understanding, correctness, and implementation. It merely requires a collection of trees and simple traversals of these trees. The split-decomposition algorithm is similar in being straightforward in its understanding and correctness. An efficient implementation of the algorithm is described that uses the union-find data-structure. A novel charging argument is used to prove the running-time. The algorithm is the first to use the recent reformulation of split decomposition in terms of graph-labelled trees. This facilitates its extension to circle graph recognition. In particular, it allows us to efficiently apply a new lexicographic breadth-first search characterization of circle graphs developed in the thesis. Lexicographic breadth-first search is additionally responsible for the efficiency of the split decomposition algorithm, and contributes to the simplicity of the modular decomposition algorithm.

Keywords: Modular Decomposition
Split Decomposition
Circle Graphs
Lexicographic Breadth-First Search
LBFS
LexBFS
Charging argument
Amortized analysis
Aggregate analysis
Recognition
Graph Labelled Trees
GLT
Advisor: Corneil, Derek
The Role of Teneurin C-terminal Associated Peptide (TCAP)-1 in the Regulation of Stress-related Behaviours

The teneurin C-terminal associated peptides (TCAPs) are a newly-elucidated family of four bioactive peptides that were found during a screen for novel corticotropin-releasing factor (CRF)-like peptide families. The predicted peptide sequences have the characteristics of a bioactive peptide and are 40 or 41 amino acid residues long. One of the peptides in the family, TCAP-1, has numerous in vitro effects, where it modulates cAMP accumulation, neuronal proliferation, neurite outgrowth, brain-derived neurotrophic factor levels, and possesses neuroprotective effects under alkalotic or hypoxic conditions. However, little is known about TCAP-1’s in vivo effects. Given the structural similarity of TCAP-1 to the CRF family, it is expected that these peptide systems may interact in vivo. The aims of this research were to 1) investigate the role of TCAP-1 on CRF- and stress-induced behaviours in rats, and determine if intracerebral TCAP-1 could modulate stress-induced anxiety-like behaviours; 2) determine the areas of the brain where TCAP-1 is taken up and is active; and 3) investigate the role of TCAP-1’s cytoskeletal modulation on stress-sensitive areas of the brain so as to determine a mechanism for long-term behavioural changes in the brain. I have established that TCAP-1 modulates anxiety-like behaviour in exploratory tests of anxiety, and that TCAP-1 is particularly active in the limbic system, including the hippocampus, amygdala, septum, and medial prefrontal cortex, and that TCAP-1 increases the dendritic spine density in the hippocampus, a brain area important for anxiety, learning, and memory. These studies have confirmed that TCAP-1 indeed plays a role in stress-like behaviours and modulates stress-related processes in the brain.

Keywords: Neuroscience
Behaviour
Endocrinology
Advisor: Lovejoy, David A.
Rotzinger, Susan
Reliability and Maintenance of Medical Devices

For decades, reliability engineering techniques have been successfully applied in many industries to improve the performance of equipment maintenance management. Numerous inspection and optimization models are developed and widely used to achieve maintenance excellence, i.e. the balance of performance, risk, resources and cost to reach to an optimal solution. However, the application of all these techniques and models to medical devices is new. Hospitals, due to possessing a large number of difference devices, can benefit significantly if the optimization techniques are used properly in the equipment management processes. Most research in the area of reliability engineering for medical equipment mainly considers the devices in their design or manufacturing stage and suggests some techniques to improve the reliability. To this point, best maintenance strategies for medical equipment in their operating context have not been considered. We aim to address this gap and propose methods to improve current maintenance strategies in the healthcare industry. More specifically, we first identify or propose the criteria which are important to assess the criticality of medical devices, and propose a model for the prioritization of medical equipment for maintenance decisions. The model is a novel application of multi-criteria decision making methodology to prioritize medical devices in a hospital according to their criticality. The devices with high level of criticality should be included in the hospital’s maintenance management program. Then, we propose a method to statistically analyze maintenance data for complex medical devices with censoring and missing information. We present a classification of failure types and establish policies for analyzing data at different levels of the device. Moreover, a new method for trend analysis of censored failure data is proposed. A novel feature of this work is that it considers dependent failure histories which are censored by inspection intervals. Trend analysis of this type of data has not been discussed in the literature. Finally, we introduce some assumptions based on the results of the analysis, and develop several new models to find the optimal inspection interval for a system subject to hard and soft failures. Hard failures are instantaneously revealed and fixed. Soft failures are only rectified at inspections. They do not halt the system, although they reduce its performance or productivity. The models are constructed for two main cases with the assumption of periodic inspections, and periodic and opportunistic inspections, respectively. All numerical examples and case studies presented in the dissertation are adapted from the maintenance data received from a Canadian hospital.

Keywords: Reliability
Maintenance
Medical Devices
Periodic Inspection
Opportunistic Inspection
Prioritization
Trend Analysis
Advisor: Jardine, Andrew K. S.
Banjevic, Dragan
High Multi-vitamin Intake During Pregnancy in Wistar Rats and the Metabolic Syndrome in the Offspring

Vitamins are readily available in the modern diet due to liberalized fortification and supplementation policies. This research tested the hypothesis that high multi-vitamin intake by Wistar rats during pregnancy leads to the development of obesity and characteristics of the metabolic syndrome in the offspring. Pregnant Wistar rats were fed the AIN-93G diet containing either the recommended (RV) or 10-fold increase (HV) in vitamin content. Pups were weaned to the RV diet (Study 1), an obesogenic liquid diet (Ob, Study 2), low vitamin diets (1/3RV or 1/6RV, Study 3), or a nutrient selection paradigm (NSP) with 10% and 60% casein diets (Study 4). Body weight (BW), food intake (FI), glucose and insulin responses, appetite hormones, abdominal fat pad mass (FPM) and systolic blood pressure (SBP) was measured. Expressions of mRNA for hypothalamic serotonin (5-HT) receptors and proopiomelanocortin (POMC) were measured in Study 4. Males, but not females, born to HV dams had higher post-weaning BW and FI when weaned to the RV or 1/3RV diet, and exhibited components of metabolic syndrome, including higher FPM, hyperglycemia, insulin resistance and elevated SBP compared with those born to RV dams. The Ob diet led to exaggerated weight gain and expressions of components of metabolic syndrome in both sexes born to dams fed the HV diet. Female pups on the 1/6RV diet from HV dams had two-fold higher glucose response and lower insulin response, but no difference in post-weaning BW and daily FI compared to those from RV dams. In contrast to the pups born to HV dams and fed a single diet, those from the HV dams and on the NSP gained less weight and ate less, and had lower hypothalamic mRNA expressions of 5-HT receptors and POMC. In conclusion, high multi-vitamin intake during pregnancy may lead to obesity, and result in a higher risk of developing characteristics of metabolic syndrome in the offspring. However, sex, weaning diet composition, and the presence of diet choice alter the outcomes.

Keywords: maternal nutrition
multi-vitamin supplementation
fetal programming
obesity
hyperphagia
metabolic syndrome
Advisor: Anderson, G. Harvey