In a description of language, Ellis (1994) claims that "the bedrock of L2 is its vocabulary" (p. 11); while for Lewis (1993), language consists of "grammaticalized lexis", not "lexicalized grammar", and Nation (2001) adds that attention to vocabulary is unavoidable. This status of vocabulary determines its pervasiveness and implies the need for attention as claimed by Meara (1980). In second and foreign language teaching and learning, instruction is an important contributor in the development and consolidation of vocabulary knowledge while Computer-Assisted Language Learning has been described as facilitative in mediating instruction and improving learner independence (Chapelle 1998, 2001; Warschauer, 1998).The present study investigates narrative comprehension, immediate and delayed vocabulary retention as a result of implicit and explicit teaching and learning of vocabulary (Hunt & Beglar, 2005), with a hypertext reading task. Many researchers support that enhanced vocabulary activities and reading for meaning affect vocabulary acquisition (Krashen, 1989, Zahar et al., 2001; Paribakht & Wesche, 1997; Lee & VanPatten, 2003). For others, the degree of involvement in the processing and the noticed properties of words determine the degree of retention (Groot, 2000; Smith, 2004).Seventy-eight fourth-semester students of French as a foreign language from six classes at an American university participated in the study. They were randomly assigned to either the implicit or the explicit conditions, and received differential treatments. The subjects read the same enhanced electronic text with permanently highlighted target items in the explicit condition, and temporarily highlighted target items in the implicit condition. The target items were hyperlinked to the same textual, auditory, and graphic enhancements. The study also makes an overview of the effect of the motivation type on the subjects' performance levels.The statistical analyses reveal both strengths and weaknesses in the two modalities with regards to immediate and delayed retention; as one of the modalities favors immediate gain and the other longer-term retention. It is thus suggested that both modalities can be jointly implemented in a Computer-Assisted Teaching and Learning condition in order to achieve higher learning outcomes. The combination may favor the dual improvement in gain and retention in the learning process.

Wir berechnen L²-Invarianten bestimmter nichtuniformer Gitter in halbeinfachen Lie-Gruppen mithilfe der Borel-Serre-Kompaktifizierung arithmetisch definierter lokalsymmetrischer Räume. Als Hauptergebnisse erhalten wir neue Abschätzungen für Novikov-Shubin-Zahlen und das Verschwinden der L²-Torsion für Gitter in Gruppen mit geradem Fundamentalrang. Wir diskutieren Anwendungen auf Gromovs Null-im-Spektrum-Vermutung sowie auf eine Proportionalitätsvermutung für die L²-Torsion maßäquivalenter Gruppen. Im Schlussteil der Arbeit beschreiben wir einen Anpassungsvorgang für Chevalley-Basen komplexer halbeinfacher Lie-Algebren. Zu einer gegebenen Realform liefert dieser eine Basis mit halb- und ganzzahligen Strukturkonstanten, die wir durch das Wurzelsystem mit Involution ausdrücken.

Inflectional verbal morphology, the system of correspondences between grammatical meanings and their means of expression, is an area of language which is difficult for adult L2 learners. The purpose of this thesis is to develop a pedagogical tool for Anglophone adult learners presenting French verbal morphology with a focus on semantics. This thesis adopts the view that explicit teaching of grammar is the most effective with these learners. Using theoretical insights from the Meaning-Text Theory, Le Morpheur, an Internet-based conjugator, has been developed. In order to see a fully-conjugated form using Le Morpheur, the user selects from a table of inflectional meanings those he wishes to express. In this way, the user becomes aware of all the meanings which must be combined to produce a verbal form. This resource was tested with a group of first-year French students at Dalhousie University. The participants were enthusiastic about Le Morpheur and the manner in which it presents French verb conjugation. These encouraging results indicate that continuing development and evaluation of this semantic-based pedagogical approach is desirable.

This paper applies an intuitive approach based on stock market data to a unique dataset of large concentrations during the period 1990-2002 to assess the effectiveness of European merger control. The basic idea is to relate announcement and decision abnormal returns. Under a set of four maintained assumptions, merger control might be interpreted to be effective if rents accruing due to the increased market power observed around the merger announcement are reversed by the antitrust decision, i.e. if there is a negative relation between announcement and decision abnormal returns. To clearly identify the events' competitive effects, we explicitly control for the market expectation about the outcome of the merger control procedure and run several robustness checks to assess the role of our maintained assumptions. We find that only outright prohibitions completely reverse the rents measured around a merger's announcement. On average, remedies seem to be only partially capable of reverting announcement abnormal returns. Yet they seem to be more effective when applied during the first rather than the second investigation phase and in subsamples where our assumptions are more likely to hold. Moreover, the European Commission appears to learn over time. (authors' abstract)

One of the most conspicuous features of mergers is that they come in waves that are correlated with increases in share prices and price/earnings ratios. We use a natural way to discriminate between pure stock market influences on firm decisions and other influences by examining merger patterns for both listed and unlisted firms. If "real" changes in the economy drive merger waves, as some neoclassical theories of mergers predict, both listed and unlisted firms should experience waves. We find significant differences between listed and unlisted firms as predicted by behavioral theories of merger waves. (author's abstract)

Ce mémoire est une étude exploratoire des représentations d'un groupe d'étudiants universitaires, relatives à l'apprentissage de l'anglais. Dans cette étude, les apprenants sont des étudiants de DUT donc la vocation est de devenir techniciens en Réseaux et Télécoms. L'étude s'est déroulée à l'IUT de Mont de Marsan qui fait partie de l'université de Pau et des Pays de l'Adour. Dans ce travail, nous nous sommes également attachés à étudier les représentations des enseignants dans le but de détecter des inadéquations entre les représentations des apprenants et celles des enseignants. Dans le but d'explorer le phénomène des représentations de différentes perspectives, nous avons utilisé diverses approches méthodologiques et théoriques. Nous avons utilisés des questionnaires (pour les étudiants et pour les enseignants), et des entretiens individuels (d'étudiants et d'enseignants). Nous avons ainsi pu rassembler des données à la fois quantitatives (issues des questionnaires) et qualitatives (issues des entretiens) que nous avons alors triangulées afin de pouvoir expliquer les données obtenues. Un des principaux résultats de cette étude fût de mettre en lumière que les représentations fondamentales des apprenants énonçaient que l'apprentissage d'une langue devait se concentrer sur la communication (compréhension et expression). Cette étude a aussi montré qu'il existait des liens entre les représentations des apprenants, leurs attentes et le type de leur motivation (intrinsèque ou extrinsèque). La plupart du temps, cette étude n'a pas montré beaucoup de différences entre les représentations et les pratiques des enseignants d'une part et les représentations et les attentes des apprenants d'autre part.

The present study investigated how 6 Korean graduate students at a Canadian university used a suite of multiple Web-based reference resources (named i-Conc), consisting of concordancers and dictionaries, as a cognitive tool for solving linguistic problems encountered over the course of completing—in English, their second language (L2)—an academic writing assignment for one of their graduate courses. Using a mixed methods design employing surveys, interviews, screen recordings, a query tracking log, and detailed case studies, the thesis provides rich descriptions of (a) the processes, and outcomes of the 6 participants’ uses of i-Conc as a reference tool for their writing authentic academic tasks and (b) their perceptions of the suite as a means of writing assistance. Overall, i-Conc served as an intellectual partner that aided the participants in strategically solving lexical and grammatical problems during their writing assignments: About 70 % of the problems they addressed with i-Conc resulted in correct text formulations or revisions. The different resources in i-Conc were each shown to have unique functions for which they were best suited, suggesting that concordancing may optimally be consulted in combination with, not in place of, other resources. The benefits of consulting i-Conc for L2 writing went beyond simply helping the participants’ problem solving to potentially facilitating their language acquisition. Input-feedback interactions with the reference suite prompted the participants to carry out robust meaning negotiations in their efforts to verify their intuitive hypotheses and to venture beyond their current linguistic repertoires. Participants acted on these potential benefits somewhat differently. Case studies and cross-case analyses demonstrated complex interactions between the participants’ individual traits and goals, the educational contexts for which they were writing, and their perceptions and evaluations of particular affordances provided by i-Conc. These findings imply that to build meaningful cognitive partnerships with reference tools, L2 writers should receive progressive guidance on principles for effective reference resource consultation along with training in strategies for using different types of resources, contingent on individuals’ abilities and ongoing needs arising from their macro and micro contexts for writing and for language learning.

The present study investigated how 6 Korean graduate students at a Canadian university used a suite of multiple Web-based reference resources (named i-Conc), consisting of concordancers and dictionaries, as a cognitive tool for solving linguistic problems encountered over the course of completing—in English, their second language (L2)—an academic writing assignment for one of their graduate courses. Using a mixed methods design employing surveys, interviews, screen recordings, a query tracking log, and detailed case studies, the thesis provides rich descriptions of (a) the processes, and outcomes of the 6 participants’ uses of i-Conc as a reference tool for their writing authentic academic tasks and (b) their perceptions of the suite as a means of writing assistance. Overall, i-Conc served as an intellectual partner that aided the participants in strategically solving lexical and grammatical problems during their writing assignments: About 70 % of the problems they addressed with i-Conc resulted in correct text formulations or revisions. The different resources in i-Conc were each shown to have unique functions for which they were best suited, suggesting that concordancing may optimally be consulted in combination with, not in place of, other resources. The benefits of consulting i-Conc for L2 writing went beyond simply helping the participants’ problem solving to potentially facilitating their language acquisition. Input-feedback interactions with the reference suite prompted the participants to carry out robust meaning negotiations in their efforts to verify their intuitive hypotheses and to venture beyond their current linguistic repertoires. Participants acted on these potential benefits somewhat differently. Case studies and cross-case analyses demonstrated complex interactions between the participants’ individual traits and goals, the educational contexts for which they were writing, and their perceptions and evaluations of particular affordances provided by i-Conc. These findings imply that to build meaningful cognitive partnerships with reference tools, L2 writers should receive progressive guidance on principles for effective reference resource consultation along with training in strategies for using different types of resources, contingent on individuals’ abilities and ongoing needs arising from their macro and micro contexts for writing and for language learning.

Les travaux de recherche de cette thèse concernent l'encadrement de la constante de Markov Bernstein pour la norme L2 associée aux mesures de Jacobi et Gegenbauer généralisée. Ce travail est composé de deux parties : dans la première partie, nous avons développé une généralisation de l'algorithme qd pour les matrices symétriques définies positives à largeur de bande $\ell$ et nous avons construit l'algorithme qd pour les matrices de Jacobi par blocs. Ensuite, nous l'avons généralisé aux cas des matrices par bloc à largeur de bande $\ell$. Ces algorithmes nous permettent de trouver un majorant de la constante. Enfin, nous avons développé le déterminant caractéristique d'une matrice symétrique définie positive pentadiagonale, ce qui nous permet d'obtenir un minorant de la constante en utilisant la méthode de Newton. La deuxième partie est consacrée à l'application de tous les outils développés à l'encadrement de la constante de Markov Bernstein pour la norme L2 associée à la mesure de Gegenbauer généralisée.

The main objective of this dissertation is to investigate the effects of acquiring a second language (L2) at later periods of language development and native-like homonym processing in the first language (L1) from the perspective of Event-Related brain Potentials (ERP) using a cross-modal lexical decision task. To date, there is a lack of neurophysiological investigations into the effect that acquiring an L2 can have on processing strategies in the L1, and whether or not there is a precise age at which L2 exposure no longer affects native-like language processing. As such, my goal is to pinpoint this sensitive period specifically for homonym processing. To achieve this, I will present and discuss the results of two studies. The first study employs behavioural response measures using a cross-modal lexical decision task where participants simultaneously heard a sentence and made a decision to a visually-presented pseudoword or real word. The second study employs ERP measures using a novel ERP paradigm which investigates not only the main objective of this dissertation, but the second objective as well. This second objective is for this dissertation to become the first to evaluate the outcome of combining the cross-modal lexical decision task with ERPs. The behavioural and neurophysiological results for the monolingual group support the Reordered Access Model (Duffy, Morris, & Rayner, 1988) while the results for the bilingual groups do not. The results of the current studies indicate that those bilinguals who acquired French as an L2 rather than as a second native L1 show increasing divergence from monolingual native speakers in L1 homonym processing, with later acquirers exhibiting an exponentially marked divergence. This was found even though the task was carried out in English, the L1 (or one of the L1s) of all participants. The diverging performances of the bilinguals from the monolinguals were apparent in behavioural responses as well as in the amplitude, scalp distribution, and latency of ERP components, These differences were unique to each group, which supports the hypothesis that the acquisition of an L2 influences processing in the L1 (Dussias & Sagarra, 2007). Specifically, the early and late bilingual groups exhibited a marked divergence from the monolingual group as they revealed syntactic priming effects (p<.001) as well as lexical frequency effects (p<.001). They also revealed the greatest P600-like effect as they processed target words which were inappropriately- related to the priming homonyms (such as skin in Richard had a shed in the back of the garden). This suggests a heightened sensitivity to surface cues due to the L2 influencing homonym processing in the L1 (Cook, 2003; Dussias & Sagarra, 2007). Comparatively, the monolingual group revealed equal N400-like effects for lexical ambiguities overall compared to the unrelated conditions, and a context-by-frequency-interaction slowing their processing of the target word that is appropriately-related to the subordinate reading of the priming homonym, suggesting that they are not as sensitive to these same surface cues. Importantly, these results confirm that using ERPs along with a cross-modal lexical decision task is a promising paradigm to further study language processing.