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This study suggests a two-step approach to identifying and interpreting regional convergence clubs in Europe. The first step involves identifying the number and composition of clubs using a space-time panel data model for annual income growth rates in conjunction with Bayesian model comparison methods. A second step uses a Bayesian space-time panel data model to assess how changes in the initial endowments of variables (that explain growth) impact regional income levels over time. These dynamic trajectories of changes in regional income levels over time allow us to draw inferences regarding the timing and magnitude of regional income responses to changes in the initial conditions for the clubs that have been identified in the first step. This is in contrast to conventional practice that involves setting the number of clubs ex ante, selecting the composition of the potential convergence clubs according to some a priori criterion (such as initial per capita income thresholds for example), and using cross-sectional growth regressions for estimation and interpretation purposes. (authors' abstract)

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Les contextes national et international sont marqués par une prise de conscience de plus en plus grande de l’importance du poisson pour la sécurité alimentaire des populations des pays sous-développés. En Mauritanie, les petits pélagiques constituent une source de protéines animales accessibles aux faibles pouvoirs d’achat et contribuent à garantir la sécurité alimentaire de nombreuses populations. Malgré la présence d’une variabilité naturelle importante des espèces pélagiques, ce travail de thèse montre qu’il existe des éléments de stabilité dans l’écosystème pélagique dans la zone nord-ouest africaine. L’hypothèse de la présence des stocks sédentaires au niveau des zones de nourriceries en Mauritanie et au Sénégal est démontrée. La répartition spatio-temporelle des sardinelles en relation avec la dynamique de l’océan (upwelling, température de surface et chlorophylle) a été examinée. L’analyse des statistiques de la pêche sur une série de plus de trente (30) ans ne soutiennent pas l’immigration en provenance du Sénégal vers la Mauritanie d'Avril à Septembre selon l’hypothèse de Boëly (1978). Ce travail de thèse examine des hypothèses de migrations possibles des sardinelles dans la zone nord-ouest africaine et d’importantes implications en matière de gestion sont discutées. Pour finir, ce travail est replacé dans son contexte plus global de l’aménagement de la pêcherie des petits pélagiques. De nouvelles perspectives pour l’application des techniques géostatistiques (indicatrices et co-krigeage) et modélisation statistique sont envisagées pour l’étude de la dynamique des stocks des sardinelles et chinchards. / National and international context marked by an awareness of growing importance of pelagic fish for food security of people in underdeveloped countries . The depletion of demersal species also makes this extremely important resource for the future pelagic fisheries in Mauritania. Mauritanian EEZ is characterized by the existence of a favorable development of several species hydro-climatic and morphological phenomena , small pelagic species that represent more than 90% of the fisheries potential is about one million tones. The major problems facing the management of these species is understanding the roles played by them in their biogeography intrinsic spatio- temporal dynamics ( short-lived , aggregation , etc. ..) and the evaluation of their abundances . Assessment of exploited fish stocks is a priority. However, the recurring difficulty of evaluations of these fisheries, naturally very unstable, often reflected a lack of precision in the methods used , the incompleteness of the data ( which is also a problem of sampling) or sampling uncontrolled .The Mauritanian small pelagic fisheries are multi-species (sardines , horse mackerel , sardinella ) . In addition to the data provided by the logbooks including the holding is mandatory for industrial units, survey data for the landing craft and coastal segment often used to calculate the abundance, acoustic surveys , are an important means for quantify the abundance and study the distribution of these resources. The data collected by observers on board fishing industrial units are also a source of important information.Based on these data , this work aims at the reconstruction of the main series of abundances of small pelagic stocks in the northern part of West Africa , to be used in the adjustment of stock assessments models. Given the importance of the environmental component in very large fluctuations observed, the integration of this dimension in the analysis of this series catches the role of each of these factors (fisheries and environment) in the variability of abundance seasonal and amplitude of their migration.In addition to these conventional data Mauritania introduced on board commercial fishing vessels with VMS . This system allows the transmission by satellite to the body control the ship's position every hour is an important technological advance. This new type of data could therefore be a new source for estimating abundance and fishing effort of small pelagic species through appropriate statistical methods. A method for the interpretation in terms of paths abundance index was applied. The coupling of VMS and logbook will help to improve the definition of nominal fishing effort and catch location at fine spatial and temporal.The general problem is how to improve the estimation of the abundance of small pelagic stocks , understand fluctuations in the abundance and migration strategy of the species as well as tactics and strategies implemented by fleets to fish resources whose behavior is often erratic . It is therefore to adresse several issues in particular:What is the trend of the evolution of the abundance of pelagic species in the North West African area? The interpretation of the trajectories in terms of VMS fishing can it be used to map the abundance of key species? What are the seasons abundances? Environmental parameters they play an important role on the distribution of species? Will there a difference between tactics and strategies of the different fleets fishing for small pelagic? Data logs and data collected by observers on board can be used as a priori knowledge? To address these issues , we proceed to the mobilization of all relevant time series and implement innovative statistical and geostatistical methods , some of which applied for the first time in the sub -region for these stocks.

Cette thèse s’inscrit dans le courant des études portant sur la relation langage-cognition enL2. L’objectif principal est d’analyser la conceptualisation spatiale dans une tâchenarrative orale (Frog story) chez plusieurs groupes d’apprenants qui se distinguent a) pourleur L1 (anglais, français, italien), b) pour leur L2 (italien, français) et c) pour leur niveaude compétence en L2 (intermédiaire vs. avancé). Pour ce faire, nous adoptons uneméthodologie impliquant des comparaisons successives entre les récits de groupes natifs etnon natifs ayant accompli la même tâche, afin de comprendre de quelle manière lesapprenants se rapprochent de la LC et s’ils sont influencés par leur L1 lors du discoursspatial en L2.L’analyse des récits natifs confirme les différences intertypologiques entre les languesverb-framed, français et italien, et satellite-framed, l’anglais (Talmy 1985). Néanmoins,une variation intra-typologique entre l’italien et le français est attestée: seul l’italienexploite des constructions satellitaires.Quant aux productions en L2, les apprenants, surtout les intermédiaires, traitent la tâche defaçon minimale (traitement prototypique, Watorek 1996) en exprimant essentiellement latrajectoire, qui représente la composante de base dans la tâche demandée. Au niveauintermédiaire, il n’y a pas de traces d’influence de la L1 sur la conceptualisation spatiale enL2, qui est, en revanche, attestée chez les apprenants anglophones avancés de l’italien L2 àtravers l’emploi de constructions satellitaires. L’existence de structures similaires dans laLS et la LC et l’évidence positive dans l’input semblent favoriser le transfert conceptuel enL2. / This thesis intervenes in the line of studies about the relation between language andcognition in L2. The main objective is to analyze spatial conceptualization in an oralnarrative task (Frog story) by several groups of learners who differ for a) their L1 (English,French, Italian), b) their L2 (Italian, French) and c) their L2 proficiency level (intermediatevs. advanced). In order to do this, we adopt a methodology that implies successivecomparisons between the productions performed by different native and non-native groupsaccomplishing the same task. The aim is to distinguish to what extent learners get closer tothe TL and if they are influenced by their L1 during the spatial production in L2.The L1 results confirm the intertypological differences between verb-framed, Italian andFrench, and satellite-framed languages, English (Talmy 1985, 2000). Nevertheless, anintratypological variation between Italian and French is attested: only Italian makes use ofsatellite constructions.As for L2 productions, learners, especially the intermediate ones, provide a minimalresponse to the task (traitement prototypique, Watorek 1996) by encoding mainly Path, thebasic component of the task. At the intermediate level, there are no traces of the influenceof the L1 on spatial conceptualization in L2, instead attested by advanced English learnersof Italian L2 through the use of satellite constructions. The existence of similar structure inthe SL and TL and the positive evidence in the input seem to favour conceptual transfertfrom L1 to L2.