The budding yeast Saccharomyces cerevisiae exhibits exquisite control of cellular size in response to the nutritional composition of its environment. Size control is mediated at the G1/S phase transition, termed Start: passage through Start represents an irreversible commitment to cell division and is contingent on achieving a critical size. When nutrients are plentiful, yeast increase their critical size set-point resulting in larger cells; in contrast, in poor nutrients, yeast pass Start at a smaller size. The genetic basis for nutrient-dependent size control and the means by which yeast sense their size remain elusive. One measure of growth potential is ribosome biogenesis, the rate of which correlates with cell size. I characterized a G-patch domain containing protein, Pfa1, which has been shown to activate the helicase activity of the pre-rRNA processing factor Prp43. Intriguingly, Pfa1 is multiply phosphorylated in response to inhibition of the TOR kinase, the central player in growth regulation. This phosphorylation occurs in a region required for Pfa1 function in ribosome biogenesis, independent of its role as a helicase activator. Consistently, phosphorylation correlates with loss of physical interactions with ribosome biogenesis and altered interactions with the ribosome. Mutation of these phosphorylation sites eliminates TOR-dependent phospho-regulation, and confers sensitivity to TOR inhibition. I propose a model wherein Pfa1 is phosphorylated in response to nutrient stress, leading to relocalization of essential processing factors, and inhibition of both ribosome biogenesis and tRNA maturation. Further, I constructed and verified a non-covalent short oligonucleotide barcode microarray platform, and applied it to genome-scale parallel analyses of both the DNA damage response and cell size control in S. cerevisiae. Through these studies, I uncovered novel connections between size control and numerous cellular processes including: the large subunit of the ribosome; the mitochondrial pH gradient; and proteins involved in oxidant-induced cell cycle arrest.

The budding yeast Saccharomyces cerevisiae exhibits exquisite control of cellular size in response to the nutritional composition of its environment. Size control is mediated at the G1/S phase transition, termed Start: passage through Start represents an irreversible commitment to cell division and is contingent on achieving a critical size. When nutrients are plentiful, yeast increase their critical size set-point resulting in larger cells; in contrast, in poor nutrients, yeast pass Start at a smaller size. The genetic basis for nutrient-dependent size control and the means by which yeast sense their size remain elusive. One measure of growth potential is ribosome biogenesis, the rate of which correlates with cell size. I characterized a G-patch domain containing protein, Pfa1, which has been shown to activate the helicase activity of the pre-rRNA processing factor Prp43. Intriguingly, Pfa1 is multiply phosphorylated in response to inhibition of the TOR kinase, the central player in growth regulation. This phosphorylation occurs in a region required for Pfa1 function in ribosome biogenesis, independent of its role as a helicase activator. Consistently, phosphorylation correlates with loss of physical interactions with ribosome biogenesis and altered interactions with the ribosome. Mutation of these phosphorylation sites eliminates TOR-dependent phospho-regulation, and confers sensitivity to TOR inhibition. I propose a model wherein Pfa1 is phosphorylated in response to nutrient stress, leading to relocalization of essential processing factors, and inhibition of both ribosome biogenesis and tRNA maturation. Further, I constructed and verified a non-covalent short oligonucleotide barcode microarray platform, and applied it to genome-scale parallel analyses of both the DNA damage response and cell size control in S. cerevisiae. Through these studies, I uncovered novel connections between size control and numerous cellular processes including: the large subunit of the ribosome; the mitochondrial pH gradient; and proteins involved in oxidant-induced cell cycle arrest.

The present study examined the structural construct validity of the LoTi Digital-Age Survey, a measure of teacher instructional practices with technology in the classroom. Teacher responses (N = 2840) from across the United States were used to assess factor structure of the instrument using both exploratory and confirmatory analyses. Parallel analysis suggests retaining a five-factor solution compared to the MAP test that suggests retaining a three-factor solution. Both analyses (EFA and CFA) indicate that changes need to be made to the current factor structure of the survey. The last two factors were composed of items that did not cover or accurately measure the content of the latent trait. Problematic items, such as items with crossloadings, were discussed. Suggestions were provided to improve the factor structure, items, and scale of the survey.

Financial ratios are key units of analysis in most quantitative financial research including bankruptcy prediction, performance and efficiency analysis, mergers and acquisitions, and credit ratings, amongst others. Since hundreds of ratios can be computed using available financial data and given the substantial overlap in information provided by many of these ratios, choosing amongst ratios has been a significant issue facing practitioners and researchers. An important contribution of the present thesis is to show that ratios can be arranged into groups where each group describes a separate financial aspect or dimension of a given firm or industry. Then by choosing representative ratios from each group, a small, yet comprehensive, set of ratios can be identified and used for further analysis. Whilst a substantial part of the financial ratio literature has focused on classifying financial ratios empirically and on assessing the stability of the ratio groups over different periods and industries, relatively little attention has been paid to the classifying of financial ratios of the banking sector. This study aims to explore the classification patterns of 56 financial ratios for banks of different type, size and age. Using data from the Uniform Bank Performance Report (UBPR), large samples of commercial, savings, and De Novo (newlychartered) commercial banks were obtained for the period between 2001 and 2005, inclusive. Principal Component Analysis (PCA) was performed on a yearly basis to classify the banks' ratios after applying the inverse sinh transformation to enhance the distributional properties of the data. The number of patterns were decided using Parallel Analysis. The study also uses various methods including visual comparison, correlation, congruency, and transformation analysis to assess the time series stability and cross-sectional similarity of the identified ratio patterns. The study identifies 13 or 14 ratio patterns for commercial banks and 10 or 11 ratio patterns for savings banks over the period on which the study is based. These patterns are generally stable over time; yet, some dissimilarity was found between the ratio patterns for the two types of banks – that is, the commercial and savings banks. A certain degree of dissimilarity was also found between the financial patterns for commercial banks belonging to different asset-size classes. Furthermore, four ratio patterns were consistently identified for the De Novo commercial banks in the first year of their operations. However, no evidence of convergence was found between the ratio patterns of the De Novo commercial banks and the ratio patterns of the incumbent (that is, long established) commercial banks. The findings of this study bring useful insights particularly to researchers who employ bank financial ratios in empirical analysis. Methodologically, this research pioneers the application of the inverse sinh transformation and parallel analysis in the area of the ratio classification literature. Also, it contributes to the use of transformation analysis as a factor comparison technique by deriving a significance test for the outputs of this analysis. Moreover, this is the only large scale study to be conducted on the classification patterns of bank financial ratios.

En dépit de ses qualités, le Rorschach en Système Intégré présente des problèmes psychométriques substantiels que le nouveau système Rorschach Performance Assessment System (R-PAS) ne permet pas de résoudre. Aussi, l’objectif principal de la thèse que nous défendons est de développer une approche psychométrique du Rorschach qui soit satisfaisante sur les plans statistique et clinique. Une Analyse Parallèle et Une Analyse en Composantes Principales réalisée sur un échantillon normatif de 695 participants Belges, Français et Finlandais permet de définir un modèle du Rorschach en 12 Composantes. Si ces dimensions sont cohérentes avec les principes de cotation et les connaissances empiriques sur le Rorschach, elles font également apparaître certaines difficultés de cotation, des aspects du Rorschach qui ont été négligés dans la recherche, de même qu’elles remettent en question certains indices du Système Intégré. Ce modèle est appliqué à deux problèmes empiriques : l’expression de particularités culturelles au Rorschach et la capacité du test à identifier des stratégies de résolution de problème (qui est un aspect central du Système Intégré). Les normes américaines du Système Intégré ainsi que les normes internationales du R-PAS ne peuvent s’appliquer de manière universelle et il faut donc recourir à des valeurs de références nationales. De plus, le Rorschach ne permet pas d’identifier des stratégies de résolution de problème de manière fiable. Ces études montrent que certains principes fondamentaux du Système Intégré et du R-PAS sont à remettre en question et qu’il est nécessaire de développer un nouveau système d’interprétation du Rorschach selon une approche psychométrique. / In spite of its quailties, the Rorschach Comprehensive System (RCS) presents substantial psychometric issues which are not solved by the new Rorschach Performance Assessment System (R-PAS). Thus, the main objective of this dissertation is to develop a satisfying psychometrical approach of the Rorschach test. A Parallel Analysis and a Principal Component Analysis performed on a normative sample of 695 Belgian, French and Fins participants define a 12 Components model of the Rorschach. If these dimensions are coherent with scoring principles and empirical evidences for the Rorschach they also reveal some scoring issues, neglected aspects of the Rorschach in the research field as well as they question the validity of some indices of the RCS. This model was applied to two empirical problems : the cross-cultural study of the Rorschach and its ability to assess problem solving strategies (which is a key feature of the RCS). The american norms of the RCS and the international reference values of the R-PAS cannot be used universally and it is necessary to use national norms. Moreover, the Rorschach does not assess problem solving strategies in a satisfying manner. These studies demonstrate that some fondamental principles of the RCS and the R-PAS must be questionned and the necessity to develop a new interpretation system for the Rorschach based on a psychometrical approach.

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