Thesis advisor: Michelle M. Meyer / As the factory responsible for producing proteins, ribosomes are of great importance. In bacteria, ribosomes are composed of three ribosomal RNAs (rRNA) of different sizes, and around 50 ribosomal proteins (r-protein). During ribosome biogenesis in bacteria, synthesis of rRNAs and r-proteins are both tightly regulated and coordinated to ensure robust growth. In particular, a group of cis-regulatory RNA elements located in the 5' untranslated regions or the intergenic regions in r-protein operons are responsible for the regulation of r-protein biosynthesis. Based on the fact that RNA-regulated r-protein biosynthesis is essential and universal in bacteria, such unique and varied regulatory RNAs could provide new targets for antibacterial purpose. In this thesis, we report and experimentally verify a novel r-protein L1 regulation model that contains dual L1-binding RNA motif, and for the first time, a S6:S18 dimer-binding RNA structure in the S6 operon. We also describe Escherichia coli-based and Schizosaccharomyces pombe-based reporter systems for in vivo characterization of RNA-protein interactions. So far, both in vivo systems failed to report RNA-protein interactions, and thus need further tuning. In addition, we performed phage-display to select for regulatory RNA-binding small peptides and examined their effects on bacteria viability. One selected peptide, N-TVNFKLY-C, caused defective growth when overexpressed in E. coli. Yet, further studies must be conducted to verify the possibility that bacteria were killed by direct RNA-peptide interaction that disrupted the native r-protein regulation. / Thesis (MS) — Boston College, 2014. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

Les apolipoprotéines L (APOL) forment une famille de protéines conservées chez les mammifères. L’APOL6 murine est principalement exprimée par les adipocytes présents dans le tissu adipeux. Dans un modèle de culture d’adipocytes, l’adipogénèse a causé l’induction de l’expression de l’APOL6. Celle-ci a pu encore être modulée à la hausse par de l’IFNγ, et à la baisse par du TGFβ. Des facteurs élevant la concentration en AMP cyclique ont aussi permis de diminuer l’expression d’APOL6. In vivo, lorsque des souris APOL6 KO ont été nourries par un régime riche en graisses, elles ont pris moins de poids que les souris WT correspondantes. De plus, les adipocytes des souris APOL6 KO obèses étaient plus petits que ceux des contrôles WT. Finalement, la recherche de protéines interagissant avec l’APOL6 par immunoprécipitation a permis de mettre en évidence une majorité de protéines associées au cytosquelette d’actine. En conclusion, l’APOL6 semble être associée au cytosquelette d’actine des adipocytes et permettrait la régulation de la taille de leurs gouttelettes lipidiques. / Apolipoproteins L (APOL) are a family of conserved proteins among mammals. Murine APOL6 is mainly expressed by adipocytes in the adipose tissue. In a model of in vitro adipocyte cell culture, adipogenesis induced the expression of APOL6. This expression increased with IFNγ and decreased with TGFβ. Cyclic-AMP elevating agents also decreased the expression of APOL6. In vivo, APOL6 KO mice that were fed with a high fat diet gained less weight than their wild type (WT) counterparts. Furthermore, adipocytes from obese APOL6 KO mice were smaller than those from WT controls. Finally, immunoprecipitation experiments showed that APOL6 probably interacted with actin cytoskeleton proteins within adipocytes. In conclusion, APOL6 is likely associated with the actin cytoskeleton in adipocytes and could be involved in the regulation of the size of lipid droplets. / Option Biologie moléculaire du Doctorat en Sciences / info:eu-repo/semantics/nonPublished

The purposes of this study were to 1) explore student attitudes toward the English-only environment in an intensive English program, and 2) find factors that either promote or inhibit students' desire to use English in their communication with compatriots in school. Qualitative research methods employed were a) a student questionnaire (with a total of 158 participants), b) semi-structured interviews with students (total 6 participants), and c) four student focus groups (with a total of 62 participants). The study was conducted at the English Language Center (ELC) at Brigham Young University. The participants were students of four native language groups (Spanish, Korean, Portuguese, Chinese) and varied levels of proficiency. The findings indicate that the majority of the students acknowledged the helpfulness of the English-only environment at the ELC, but recognized some factors that prevented them from speaking only English in the school building. These factors were grouped into five categories: sociocultural, linguistic, individual, psychological, and institutional. The sociocultural factors included peer pressure, fear of negative evaluation by compatriots, cultural communication patterns, maintaining friendship with compatriots, and need for cultural bonding. The linguistic factors included low language proficiency, difficulty in understanding teachers' assignments, translating habits, and linguistic differences between English and students' L1. The category of the individual factors consisted of the intensity of motivation and personality type. Lack of confidence, stress from speaking English, and fear of having a different personality when speaking English were categorized as psychological factors. Finally, the institutional category included physical factors (number of students of the same L1 in school/class, distance from the university campus), teacher factors (teachers' ability to motivate students, other teachers' characteristics [being sensitive to students' cultures, understanding students' individual circumstances, the ability to establish a rapport with students]), and curricular and administrative factors (poor enforcement of the English-only rule, weaknesses of speaking classes, lack of activities that promote interaction with students from other countries). This study provides a deep understanding of the reasons why many students speak their native language once they leave the English classroom. Based on these findings, recommendations regarding the development and modification of curricula in order to improve the language-learning environment at English institutions are offered to classroom teachers and program administrators.

Numerous events during development require the tightly controlled and regulated interaction of cells - from gastrulation in the early embryo to axonal pathfinding and remodeling of synaptic networks. Each of these events is dependent upon signals generated by cell-cell interactions, which are in turn specified by a diverse number of cell adhesion molecules. Many families of cell adhesion molecules have been described, and these fall into the broad categories of cadherins, immunoglobulin superfamily (IgSF) members, selectins, and integrins. Activated Leukocyte Cell Adhesion Molecule (ALCAM) is a member of the IgSF, and controls numerous developmental processes, ranging from hematopoiesis to neuronal targeting. Furthermore, this protein has been implicated in the progression of numerous cancers of diverse origins. Despite the variety of developmental and pathological processes in which ALCAM has been implicated, little is known about how it signals in the cell - few extracellular binding partners have been isolated, and, as of this writing, no cytoplasmic interactors have been identified. The purpose of the work presented in this thesis was to elucidate the mechanisms by which ALCAM influences cell behavior, specifically in uveal melanoma cells, and to determine novel extra- and intracellular ligands. Here, I report the regulation of cadherin-based junctions by ALCAM in uveal melanoma cells, as well as provide evidence for a novel extracellular interaction with L1 cell adhesion molecule, and identify three novel intracellular binding partners.

Cette thèse étudie différents problèmes de minimisations avec des fonctions de régularisations qui promeuvent la parcimonie. Plus précisément, on souhaite reconstruire une image, que l'on suppose parcimonieuse et qui a subit une transformation après un opérateur linéaire, à l'aide de problèmes de minimisations. Dans ce manuscrit, on s'intéressera plus particulièrement à la minimisation l1 synthèse, analyse et bloc qui sont très utilisées pour reconstruction une image que l'on sait parcimonieuse. Ces minimisations produisent en pratique des résultats convaincants qui n'ont été compris théoriquement que récemment. Les différents travaux sur le sujet mettent en évidence le rôle d'un vecteur particulier appelé certificat dual. L'existence d'un certificat dual permet à la fois d'assurer la reconstruction exacte d'une image dans le cas où il n'y a pas de perturbations et d'estimer l'erreur de la reconstruction en présence de perturbations. Dans nos travaux, nous allons introduire l'existence d'un certifical dual optimal pour la minimisation l1 synthèse qui minimisent l'erreur de reconstruction. Ces résultats ayant une forte interprétation géométrique, nous avons développé un critère identifiabilité, c'est à dire que ce critère assure que l'image recherchée est l'unique solution du problème de minimisation. Ce critère permet d'étendre nos travaux à la minimisation l1 analyse, l1 bloc et à d'autres cas. / This thesis studies different minimization problems with sparses based regularization. More precisely, we want to reconstruct a sparses image, which undergone a linear transformation, with minimization problems. In this manuscript, we will be focused on l1 synthesis, analysis and block minimization which are widely used in sparse approximations. These problems offer competitive results which are theorietical understood only recntly. Different studies on the subject emphasized the contribution of a particular vector called dual certificate. The existence of this dual certificate allows simultaneously to guarantee the exact recovey of an image in noiseless case and to estimate the noise robustness in noisy case. In this work, we introduce eth existence of an optimal dual certificate for the l1 synthesis minimization which minimizes the reconstruction error. As those results have a strong geometrical interpretation, we develop an identifiability criterion which ensures the uniqueness of a solution. This criterion generalizes the work on l1 synthesis minimization tothe analysis case, block case and others.

This thesis examined the factors of L1, input frequency and emergent productivity in child L2 acquisition. This thesis is the first study to look at the interplay of L1 and usage factors in children learning a L2. The focus of the thesis was an investigation of these factors in the acquisition of article and auxiliary systems of English, which have been proven to be problematic areas for both L1 and L2 learners. While accounts of L1 transfer in L2 are better developed in generative theory, the roles of input frequency and emergent productivity are better developed in constructivist theory. The thesis assessed these two approaches against the data from L2 children from various L1 backgrounds. The children’s accuracy and error patterns with articles and auxiliaries were investigated. The main findings were as follows. L1 typology facilitated the acquisition of the structure of the NP and VP, but it only extended as far as the awareness of the presence of the functional morpheme (article or auxiliary). L1 transfer effects were observed only in the first 1.5 years of acquisition, which could be due to the unstable L1 knowledge in child L2 learners. The use of articles and auxiliaries was also influenced by their input frequencies and distribution, as more frequent forms were supplied more accurately and were substituted for less frequent forms. Different forms of articles and auxiliaries emerged separately and followed different paths of development. It was argued that they were acquired piecemeal and that productivity with these forms emerged gradually. It was concluded that constructionist theories were better supported by the data, since the findings on input frequency and productivity were not compatible with the generative approach, and L1 transfer was incorporated into the constructionist approach to account for the findings. It was argued that by the onset of acquisition, child L2 learners had established constructions in their L1 that were abstract enough to be transferred to L2 and did not rely on lexically specific information. As all children learned specific morphological forms of L2 piecemeal, in doing so they demonstrated input effects that held across all L1 backgrounds.

Dieser Band versammelt Originaldaten aus einer Erhebung, die im Rahmen des SFB-Teilprojekts B6 „Kiezdeutsch“ im Frühjahr 2010 in Berlin und İzmir, Türkei, durchgeführt wurde. Sämtliche hier dokumentierten Daten wurden schriftlich produziert; sie stammen von drei verschiedenen Sprechergruppen: Jugendliche aus einem multiethnischen Berliner Wohngebiet, die untereinander Kiezdeutsch sprechen, Jugendliche aus einem monoethnischen Berliner Wohngebiet, in dem der traditionelle Berliner Dialekt vorherrscht, und türkische Jugendliche in İzmir, die Deutsch als Fremdsprache gesteuert erworben haben.

In system identification, the Akaike Information Criterion (AIC) is a well known method to balance the model fit against model complexity. Regularization here acts as a price on model complexity. In statistics and machine learning, regularization has gained popularity due to modeling methods such as Support Vector Machines (SVM), ridge regression and lasso. But also when using a Bayesian approach to modeling, regularization often implicitly shows up and can be associated with the prior knowledge. Regularization has also had a great impact on many applications, and very much so in clinical imaging. In e.g., breast cancer imaging, the number of sensors is physically restricted which leads to long scantimes. Regularization and sparsity can be used to reduce that. In Magnetic Resonance Imaging (MRI), the number of scans is physically limited and to obtain high resolution images, regularization plays an important role. Regularization shows-up in a variety of different situations and is a well known technique to handle ill-posed problems and to control for overfit. We focus on the use of regularization to obtain sparseness and smoothness and discuss novel developments relevant to system identification and signal processing. In regularization for sparsity a quantity is forced to contain elements equal to zero, or to be sparse. The quantity could e.g., be the regression parameter vectorof a linear regression model and regularization would then result in a tool for variable selection. Sparsity has had a huge impact on neighboring disciplines, such as machine learning and signal processing, but rather limited effect on system identification. One of the major contributions of this thesis is therefore the new developments in system identification using sparsity. In particular, a novel method for the estimation of segmented ARX models using regularization for sparsity is presented. A technique for piecewise-affine system identification is also elaborated on as well as several novel applications in signal processing. Another property that regularization can be used to impose is smoothness. To require the relation between regressors and predictions to be a smooth function is a way to control for overfit. We are here particularly interested in regression problems with regressors constrained to limited regions in the regressor-space e.g., a manifold. For this type of systems we develop a new regression technique, Weight Determination by Manifold Regularization (WDMR). WDMR is inspired byapplications in biology and developments in manifold learning and uses regularization for smoothness to obtain smooth estimates. The use of regularization for smoothness in linear system identification is also discussed. The thesis also presents a real-time functional Magnetic Resonance Imaging (fMRI) bio-feedback setup. The setup has served as proof of concept and been the foundation for several real-time fMRI studies.

I denna studie fokuserar vi på hur lärare kan öka inlärningen för elever med ett andraspråk. Studien är huvudsakligen indelad i två delar, där den innehållsliga och metodlogiska delen ingår. Omfånget på studien är tolv artiklar med olika typer av inriktning och resultat. Utgångspunkten är det sociokulturella perspektivet med särskild teoretisk förankring i Vygotskij och Hundeide. I resultatet kan vi se att det finns flera metoder som har en positiv inverkan på andraspråksinlärningen. Bland annat lyfter vi fram att datorbaserad programvara kan vara ett redskap för att undersöka hur elever skriver texter och annat material. Frågan kring att använda sig av modersmålet i undervisningen har lett till delade åsikter och uppfattningar, vilka också presenteras i studien.

This research explores both industry and temporal aspects of entry, exit and industry turbulence in Austrian manufacturing in the period between 1981 to 1994. It is shown that while the net entry of both firms and establishments is quite stable over time, exit and especially the turnover and volatility of firms is influenced more by temporal effects. A regression analysis into the determinants of industry dynamics associated with entry and exit shows that sunk costs, scale economies and industry growth are primary determinants for different entry and exit regimes across 2-digit sectors, while profitability is found to be significant for dynamics related to exit but not for the entry of firms. The net entry dynamics of firms and establishments are found to be different in regard to capital intensity and profitability. (author's abstract) / Series: Working Papers Series "Growth and Employment in Europe: Sustainability and Competitiveness"