Initiation der Translation ist ein komplexer und stark regulierter Prozess, bei dem Ribosomen die mRNA binden. Die überwiegende Mehrheit eukaryotischer mRNAs wird durch einen 5‘-Cap-abhängigen Mechanismus translatiert. Dazu bindet der eIF4F-Proteinkomplex die mRNA an der 5'-Cap-Struktur, um weitere eIFs und die kleine ribosomale Untereinheit zu rekrutieren, welche dann die 5'UTR von 5'- in 3'-Richtung bis zu einem Startcodon scannt. Anschließend trifft die große ribosomale Untereinheit dazu und die Proteinsynthese beginnt. Darüber hinaus kann die Translation durch IRES, interne ribosomale Eintrittsstellen, vermittelt werden, welche das Ribosom unabhängig von Cap und 5‘-Ende zum Startcodon rekrutieren. Die zelluläre IRES-vermittelte Translation gilt als ineffizient unter physiologischen Bedingungen, wird aber durch Stress aktiviert. Da die Regulation dieses Mechanismus weitaus unbekannt ist, haben wir die zelluläre, Cap-unabhängige Translationsinitiation untersucht. Dafür haben wir eine embryonale Stammzelllinie generiert, welche eine dominant-negative Mutante von 4E-BP1 exprimiert. 4E-BP1 bindet das 5‘-Cap-bindende Protein, sodass eIF4F nicht am 5'-Cap andocken kann. Wir haben das Proteom während der Überexpression von 4E-BP1 und der neuronalen Differenzierung bestimmt, um Translationsdynamiken systemisch zu erfassen. Gene mit verminderter Sensitivität für die Cap-abhängige Translation wurden so identifiziert und in bicistronischen Reporter-Assays getestet. Nach strenger Validierung wurde eine Cap-unabhängig translatierte mRNA, Pqbp1, entdeckt. Der zweite Teil dieser Studie untersuchte die Cap-unabhängige Translation einer circRNA, welche keine freien Enden hat und daher per IRES translatiert werden muss. Wir konnten bestätigen, dass circMbl in vitro translatiert wird und konnten so innerhalb eines Kooperationsprojekts zu der Erkenntnis beitragen, dass circRNAs im Fliegengehirn translatiert werden. / Translation initiation is a complex and highly regulated process which involves the assembly of an elongation competent ribosome on the mRNA. The vast majority of eukaryotic mRNAs is translated by a canonical cap-dependent mechanism. This requires the eIF4F protein complex to bind the mRNA at the 5’-cap to recruit further eIFs and the small ribosomal subunit which then scans the 5’UTR in 5’ to 3’ direction until a start codon is encountered. Afterwards the large ribosomal subunit joins and protein synthesis begins. Besides that, translation of mRNAs can be mediated by IRESs, internal ribosome entry sites, which recruit the ribosome in a cap and 5’-end-independent manner to the start codon. Such cellular IRES-mediated translation is thought to be inefficient under physiological conditions but activated during stress. As the regulation of this mechanism is not well understood, we aimed to elucidate cellular cap-independent translation events. Therefore, we generated a mouse embryonic stem cell line with inducible overexpression of a dominant negative mutant of 4E-BP1. 4E-BP1 sequesters the cap-binding protein eIF4E so that the eIF4F protein complex fails to assemble at the 5’-cap. We performed shotgun proteomics during 4E‑BP1 overexpression and neuronal differentiation to globally monitor translation dynamics. Genes with reduced sensitivity for cap-dependent translation were identified and tested for internal translation initiation in bicistronic reporter assays. After stringent validation one cap-independently translated mRNA, Pqbp1, was discovered. The second part of this study investigated cap-independent translation initiation on a circRNA, which by nature lacks free ends and thus requires IRES-mediated translation. We could show that circMbl is translated in vitro and thus contributed to the scientific evidence for the translation of circRNAs in fly brain, which was studied in a collaboration project.

Cette étude cherche à explorer et à éclairer le rôle et la place de la famille dans une communauté acadienne à l'époque de la survivance acadienne, c'est-à-dire au XIXe siècle. C'est l'approche de la reconstitution des familles inspirée de la méthode Henry qui nous a servi dans notre démarche. A partir des données généalogiques, nous avons pu comprendre les mécanismes mis en place par la communauté acadienne en vue de s'étendre dans l'espace durant la phase de peuplement de la région de Cap-Pelé - Chimougoui et à l'époque de l'émigration vers les centres urbains des Maritimes et des états de la Nouvelle-Angleterre. La famille, en milieu acadien, est présente dans toutes les sphères d'activités, que ce soit dans l'arène politique ou au sein des structures paroissiales ou scolaires. Seul le domaine économique ne semble pas réserver une place prépondérante à la famille, comme quoi le monde des affaires lui échappe. C'est dans la mesure où la famille a réussi à se reproduire que la survivance du peuple acadien a été assurée au XIXe siècle. Au début de l'établissement de Cap-Pelé - Chimougoui, l'abondance des terres favorise les pratiques égalitaires dans le mode de dévolution des biens. Avec la saturation de l'espace agricole, les pratiques successorales deviennent moins égalitaires. Toutefois, le développement progressif de l'industrie de la pêche au homard change complètement les enjeux. Pour les familles qui habitent les villages côtiers et qui s'adonnent davantage à la pêche, le rapport à la terre se transforme. Ces familles n'hésitent pas à morceler le patrimoine foncier favorisant ainsi un partage plus égalitaire où les filles ne sont pas exclues. Ce sont ces familles qui réussissent le mieux à garder leurs enfants auprès d'elles et, par le fait même, à assurer leur présence dans la communauté. / Québec Université Laval, Bibliothèque 2014

Climate change has become an important concern for most governments in the current day. The impact of global warming on economic productivity, human welfare and environmental sustainability is becoming increasingly apparent to most people on the planet, resulting in a rapid evolution of policy instruments which are capable of addressing the issue of climate change. The ultimate aim of these policy instruments is to influence corporate activity to environmentally sustainable behaviour. The two most common policy instruments to effect change to most environmentally sustainable behaviour is carbon taxation and cap-and-trade schemes. Linked to climate change and environmental sustainability is the concept of sustainable development which encompasses environmental sustainability, economic sustainability and social sustainability. These principles are formalized and made relevant for companies in the form of the triple bottom line. In South Africa, National Treasury implemented a carbon excise tax in 2010 for the motor vehicle manufacturing industry in response to the problem of global warming, and published a discussion document in support of their decision to implement carbon tax. The document highlighted reasons for the choice of carbon tax over other policy instruments such as cap-and-trade schemes and penalties. Even though the choice for carbon tax was assessed from an environmental perspective, the concept of sustainable development encompasses environmental, economic and social sustainability. The subject matter for the 1st article was to compare the two most widely used climate change instruments, known as cap-and-trade schemes and carbon tax, from the broader perspective of sustainable development. This included an analysis of the effects of both instruments on both greenhouse gases as well as economic indicators such as gross domestic product (GDP) and fiscal revenue. Linked to the implementation of any instrument designed to address carbon emissions is the concept of the social cost of carbon (SCC). The SCC is an estimate of the associated monetary cost of the damage cause by emitting one additional ton of carbon into the atmosphere. In a perfect world the SCC would be equal to, or lower than, the carbon tax price. National Treasury‟s carbon tax price has never been assessed from an economic perspective and in particular whether the price equates to the SCC from a feasibility viewpoint. The testing of the carbon tax price against the SCC from an economic perspective was the subject of the 2nd article, which then also evaluated the impact of carbon tax on motor vehicle manufacturer‟s production techniques and vehicle fuel efficiency. Under the assumption that the carbon tax price approximates the SCC it is arguable that companies are effectively paying for the damage cost to the environment in the form of the carbon excise tax implemented. If the argument holds true, then the corporate social investment expenditure may well be adjusted since corporate responsibilities to the environment have been partially addressed by the payment of carbon tax. The impact of carbon tax on CSI expenditure by motor vehicle manufacturers in South Africa was the subject of the 3rd article in the thesis. Furthermore, also linked to the implementation of carbon taxation for the motor vehicle industry is the financial and sustainability reporting of the motor vehicle manufacturers‟ tax in the sustainability report and financial statements. Since carbon tax was designed to promote behaviour toward a lower carbon footprint, evidence that such behaviour is being affected can be observed in a company‟s sustainability report, which specifies the company‟s planned path to carbon reduction in accordance with the disclosure standards set in the Global Reporting Initiative (GRI). In terms of financial accounting there is no specific International Financial Reporting Standard (IFRS) statement dealing with carbon tax, and the correct treatment thereof will have to be interpreted in accordance with existing accounting standards on revenue (IAS 18) and provisions (IAS 37). The subject matter of 4th article assessed motor vehicle manufacturers reporting compliance of carbon tax transactions in accordance with IFRS and the GRI. In summary, the implementation of carbon tax in South Africa is seen as a significant move in the fight against climate change. If the instrument is to be considered effective it must prove to be sustainable from an environmental, economic and social perspective. The effectiveness of the instrument can only be measured if it was accurately reported in the financial statements and sustainability reports in accordance with IFRS and the GRI. Furthermore, the instrument should not be seen as an opportunity by motor vehicle manufacturers to forego corporate responsibility to environment and thus should not impact CSI expenditure which is a significant part of the welfare contribution by South African businesses to the people of South Africa. / PhD (Tax), North-West University, Potchefstroom Campus, 2014

Climate change has become an important concern for most governments in the current day. The impact of global warming on economic productivity, human welfare and environmental sustainability is becoming increasingly apparent to most people on the planet, resulting in a rapid evolution of policy instruments which are capable of addressing the issue of climate change. The ultimate aim of these policy instruments is to influence corporate activity to environmentally sustainable behaviour. The two most common policy instruments to effect change to most environmentally sustainable behaviour is carbon taxation and cap-and-trade schemes. Linked to climate change and environmental sustainability is the concept of sustainable development which encompasses environmental sustainability, economic sustainability and social sustainability. These principles are formalized and made relevant for companies in the form of the triple bottom line. In South Africa, National Treasury implemented a carbon excise tax in 2010 for the motor vehicle manufacturing industry in response to the problem of global warming, and published a discussion document in support of their decision to implement carbon tax. The document highlighted reasons for the choice of carbon tax over other policy instruments such as cap-and-trade schemes and penalties. Even though the choice for carbon tax was assessed from an environmental perspective, the concept of sustainable development encompasses environmental, economic and social sustainability. The subject matter for the 1st article was to compare the two most widely used climate change instruments, known as cap-and-trade schemes and carbon tax, from the broader perspective of sustainable development. This included an analysis of the effects of both instruments on both greenhouse gases as well as economic indicators such as gross domestic product (GDP) and fiscal revenue. Linked to the implementation of any instrument designed to address carbon emissions is the concept of the social cost of carbon (SCC). The SCC is an estimate of the associated monetary cost of the damage cause by emitting one additional ton of carbon into the atmosphere. In a perfect world the SCC would be equal to, or lower than, the carbon tax price. National Treasury‟s carbon tax price has never been assessed from an economic perspective and in particular whether the price equates to the SCC from a feasibility viewpoint. The testing of the carbon tax price against the SCC from an economic perspective was the subject of the 2nd article, which then also evaluated the impact of carbon tax on motor vehicle manufacturer‟s production techniques and vehicle fuel efficiency. Under the assumption that the carbon tax price approximates the SCC it is arguable that companies are effectively paying for the damage cost to the environment in the form of the carbon excise tax implemented. If the argument holds true, then the corporate social investment expenditure may well be adjusted since corporate responsibilities to the environment have been partially addressed by the payment of carbon tax. The impact of carbon tax on CSI expenditure by motor vehicle manufacturers in South Africa was the subject of the 3rd article in the thesis. Furthermore, also linked to the implementation of carbon taxation for the motor vehicle industry is the financial and sustainability reporting of the motor vehicle manufacturers‟ tax in the sustainability report and financial statements. Since carbon tax was designed to promote behaviour toward a lower carbon footprint, evidence that such behaviour is being affected can be observed in a company‟s sustainability report, which specifies the company‟s planned path to carbon reduction in accordance with the disclosure standards set in the Global Reporting Initiative (GRI). In terms of financial accounting there is no specific International Financial Reporting Standard (IFRS) statement dealing with carbon tax, and the correct treatment thereof will have to be interpreted in accordance with existing accounting standards on revenue (IAS 18) and provisions (IAS 37). The subject matter of 4th article assessed motor vehicle manufacturers reporting compliance of carbon tax transactions in accordance with IFRS and the GRI. In summary, the implementation of carbon tax in South Africa is seen as a significant move in the fight against climate change. If the instrument is to be considered effective it must prove to be sustainable from an environmental, economic and social perspective. The effectiveness of the instrument can only be measured if it was accurately reported in the financial statements and sustainability reports in accordance with IFRS and the GRI. Furthermore, the instrument should not be seen as an opportunity by motor vehicle manufacturers to forego corporate responsibility to environment and thus should not impact CSI expenditure which is a significant part of the welfare contribution by South African businesses to the people of South Africa. / PhD (Tax), North-West University, Potchefstroom Campus, 2014

Résumé : La région de l'archipel canadien, située en Arctique, connaît actuellement d'importants changements climatiques, se traduisant notamment par une augmentation des températures, une réduction de l'étendue de la banquise marine et du couvert nival terrestre ou encore une perte de masse significative des calottes glaciaires disséminées sur les îles de l'archipel. Parmi ces calottes glaciaires, la calotte Barnes, située en Terre de Baffin, ne fait pas exception comme le montrent les observations satellitaires qui témoignent d'une importante perte de masse ainsi que d'une régression de ses marges, sur les dernières décennies. Bien que les calottes glaciaires de l'archipel canadien ne représentent que quelques dizaines de centimètres d'élévation potentielle du niveau des mers, leur perte de masse est une composante non négligeable de l'augmentation actuelle du niveau des mers. Les projections climatiques laissent à penser que cette contribution pourrait rester significative dans les décennies à venir. Cependant, afin d'estimer les évolutions futures de ces calottes glaciaires et leur impact sur le climat ou le niveau des mers, il est nécessaire de caractériser les processus physiques tels que les modifications du bilan de masse de surface. Cette connaissance est actuellement très limitée du fait notamment du sous-échantillonnage des régions arctiques en terme de stations météorologiques permanentes. Une autre particularité de certaines calottes de l'archipel canadien, et de la calotte Barnes en particulier, est de présenter un processus d'accumulation de type glace surimposée, ce phénomène étant à prendre en compte dans l'étude des processus de surface. Pour pallier au manque de données, l'approche retenue a été d'utiliser des données de télédétection, qui offrent l'avantage d'une couverture spatiale globale ainsi qu'une bonne répétitivité temporelle. En particulier les données acquises dans le domaine des micro-ondes passives sont d'un grand intérêt pour l'étude de surfaces enneigées. En complément de ces données, la modélisation du manteau neigeux, tant d'un point de vue des processus physiques que de l'émission électromagnétique permet d'avoir accès à une compréhension fine des processus de surface tels que l'accumulation de la neige, la fonte, les transferts d'énergie et de matière à la surface, etc. Ces différents termes sont regroupés sous la notion de bilan de masse de surface. L'ensemble du travail présenté dans ce manuscrit a donc consisté à développer des outils permettant d'améliorer la connaissance des processus de surface des calottes glaciaires du type de celles que l'on rencontre dans l'archipel canadien, l'ensemble du développement méthodologique ayant été réalisé sur la calotte Barnes à l'aide du schéma de surface SURFEX-CROCUS pour la modélisation physique et du modèle DMRT-ML pour la partie électromagnétique. Les résultats ont tout d'abord permis de mettre en évidence une augmentation significative de la durée de fonte de surface sur la calotte Barnes (augmentation de plus de 30% sur la période 1979-2010), mais aussi sur la calotte Penny, elle aussi située en Terre de Baffin et qui présente la même tendance (augmentation de l'ordre de 50% sur la même période). Ensuite, l'application d'une chaîne de modélisation physique contrainte par diverses données de télédétection a permis de modéliser de manière réaliste le bilan de masse de surface de la dernière décennie, qui est de +6,8 cm/an en moyenne sur la zone sommitale de la calotte, qui est une zone d'accumulation. Enfin, des tests de sensibilité climatique sur ce bilan de masse ont permis de mettre en évidence un seuil à partir duquel cette calotte voit disparaître sa zone d'accumulation. Les modélisations effectuées suggèrent que ce seuil a de fortes chances d'être atteint très prochainement, pour une augmentation de température moyenne inférieure à 1°C, ce qui aurait pour conséquence une accélération de la perte de masse de la calotte. // Abstract : Significant climate change is curently monitored in the Arctic, and especially in the region of the canadian arctic archipellago. This climate warming leads to recession of seaice extent and seasonnal snow cover, and also to large mass loss of the archipellago’s ice caps. One of the most southern ice cap, the Barnes Ice Cap, located on the Baffin Island, is no exception to significant mass loss and margins recession as satellite observations exhibited over the last decades. Despite the relative low sea level potential of the small ice caps located in the canadian arctic achipellago in regards to major ice sheets, Antarctica and Greenland, their contribution to the current sea level rise is significant. Climate projections show that this contribution could accelerate significant over the next decades. However, to estimate the future evolution of these ice caps and their impact on climate or sea level rise, a better characterisation of the surface processes such as the evolution of the surface mass balance is needed. This knowledge is currently very limited, mainly due to the sparse covering of automatic weather stations or in-situ measurements over the Arctic. Furthermore, several ice caps, among with the Barnes Ice Cap, present a superimposed ice accumulation area which particularities have to be taken into account in the surface processes studies. Given the lack of in-situ data, the approach choosen in this work is to use remote sensing data, that have the advantage to offer a good spatial and temporal coverage. In particular, passive microwave data are very suitable for snowy surfaces studies. To complement these data, physical and electromagnetic snowpack modeling provide a fine characterisation of surface processes such as snow accumulation. The whole work presented in this manuscript thus consisted in developping specific tools to improve the understanding of surface processes of small arctic ice caps. This methodological development was performed and applied on the Barnes Ice Cap using the surface scheme SURFEX-CROCUS and the electromagnetic model DMRT-ML. First results highlight a significant increase in surface melt duration over the past 3 decades on the Barnes Ice Cap (increase of more than 30% over 1979-2010 period). A similar trend is also monitored over the Penny Ice Cap, located in the south part of the Baffin Island (increase of more than 50% over the same period). Then, the surface mass balance over the last decade was modeled by using a physical based modeling chain constrained by remote sensing data. The results give a mean net accumulation of +6,8 cm y−1 on the summit area of the ice cap. Finaly, sensitivity tests, performed to investigate the climatic sensitivity of the surface mass balance, highlight a threshold effect that may lead to a complete disapearence of the accumulation area of the Barnes Ice Cap. With a temperature increase less than 1°C, modeling results suggest it is likely that the threshold will be reached rapidly leading to an increase in mass loss from the ice cap.

This thesis aims at investigating the importance of effective implementation of health safety and hygiene legislations and practices in Health Care delivery systems. A new System Based Approach for Strategic Implementation of Occupational Health & Safety Practices is proposed in this thesis. The underlying principle of the approach is based on involvement and inputs from staff and management rather than by pre-specified requirements and objectives. Furthermore, the development process is a closed loop process that provides a mechanism for continuously evaluating system performance and monitoring activities that have considerable impact on health and safety practices. A case study was conducted in the medical laboratories of five major hospitals in the Emirate of Abu Dhabi. Data were collected through questionnaires, staff interviews, and reviewing laboratory safety reports compiled over a three years period. The main conclusions from this study are: 1. The proposed approach has proven to be useful in analyzing existing health and safety systems. The methodology and tools proved to be instrumental in defining inefficiencies and determining the status of the Health & Safety policies & practices in the selected medical laboratories. 2. Effective implementation of the proposed approach has shown improvements in productivity, operational cost, service quality, staff and management satisfaction. 3. The case study has demonstrated that a developing country such the UAE, with no previously existing Health & Safety legislation and little risk prevention culture, can rapidly and effectively introduce effective industry specific H&S by adopting an integrated systems based approach. 4. UAE has highly advanced and economically developing base, there is a general willingness at senior level within the UAE to achieve high levels of competence and standards in all industrial sectors. 5. CAP is a system based management tool which has been implemented globally, but only limited in the gulf region; CAP has been implemented by the author and colleges within Zayed Military Hospital between 2003-2007.

Les compositions isotopiques de Sr, Nd et Pb des basaltes d'îles océaniques ont été mesurées de manière systématique depuis 30 ans. Les variations de ces compositions sont classiquement interprétées comme la signature du mélange entre des composants présents au sein des panaches mantelliques. Cependant elles peuvent aussi représenter des interactions entre les magmas et les réservoirs qu'ils traversent au cours de leurs remontées vers la surface. Après avoir mis en évidence les processus pouvant altérer la composition initiale d'un magma et proposer des moyens de s'en affranchir, 2 études locales sont éffectuées (îles de Sao Nicolau et de Sao Jorge, archipels du Cap Vert et des Açores). Ces deux études montrent la part importante des variations d'origine superficielle dans ces deux localités. Ces résultats sont ensuite généralisés à d'autres localités clés de la topologie mantellique et permettent de discuter d'un composant primitif ubiquiste dans les panaches mantelliques

During this project NoSQL technologies for Hotel IT have been evaluated. It has been determined that among NoSQL technologies, document database fits the best this use-case. Couchbase and MongoDB, the two main documents stores have been evaluated, their similarities and differences have been highlighted. This reveals that document-oriented features were more developed in MongoDB than Couchbase, this has a direct impact on search of reservations functionality. However Couchbase offers a better way to replicate data across two remote data centers. As one of the goals was to provide a powerful search functionality, it has been decided to use MongoDB as a database for this project. A proof of concept has been developed, it enables to search reservations by property code, guest name, check-in date and check-out date using a REST/JSON interface and confirms that MongoDB could work for storing hotel reservations in terms of functionality. Then different experiments have been conducted on this system such as throughput and response time using specific hotel reservation search query and data set. The results we got reached our targets. We also performed a scalability test, using MongoDB sharding functionalities to distribute data across several machines (shards) using different strategies (shard keys) so as to provide configuration recommendations. Our main finding was that it was not necessary to always distribute the database. Then if "sharding" is needed, distributing the data according to the property code will make the database go faster, because queries will be sent directly to the good machine(s) in the cluster and thus avoid "scatter-gather" query. Finally some search optimizations have been proposed, and in particular how an advanced search by names could be implemented with MongoDB. / <p>This thesis is submitted in the framework of a double degree between Compiègne University Of Technology (UTC) and Linköping University (LiU)</p>

Este trabajo presenta un catálogo de técnicas y patrones de diseño aplicados actualmente en bases de datos NoSQL. El enfoque propuesto consiste en una presentación del estado del arte de las bases de datos NoSQL, una exposición de los conceptos claves relacionados y una posterior exhibición de un conjunto de técnicas y patrones de diseño orientados a la escalabilidad y alta disponibilidad. Para tal fin, • Se describen brevemente las características principales de los bases de datos NoSQL, cuales son los factores que motivaron su aparición, sus diferencias con sus pares relacionales, se presenta el teorema CAP y se contrasta las propiedades ACID contra las BASE. • Se introducen las problemáticas que motivan las técnicas y patrones de diseño a describir. • Se presentan técnicas y patrones de diseños que solucionen las problemáticas. • Finalmente, se concluye con un análisis integrador, y se indican otros temas de investigación pertinentes.

Dans le milieu scientifique polonais, peu de travaux concernent l'Afrique du Sud et les communautés polonaises y habitant. Pourtant, ce territoire constitue un laboratoire social unique et les Polonais de l'Afrique du Sud sont soumis à des phénomènes qui peuvent retenir l'attention des sociologues. Cette recherche s'applique à repérer la dimension identitaire de ces phénomènes dynamiques avec l'exemple des trois vagues migratoires des Polonais habitant la ville du Cap. En alliant les techniques qualitatives de recherche en sciences sociales et la tradition de l'Ecole de Chicago de collecte des données, je présente l'évolution de l'attachement au pays d'origine, ainsi que différents types d'identité plurielle. La première partie est consacrée à la présentation historique et sociologique de mon terrain de recherche : l'Afrique du Sud en général, mais aussi les particularités de la région du Cap. Cette contextualisation comprend : l'organisation spatiale du Cap, la problématique interethnique dans la réalité post-apartheid, les conséquences urbaines des préjugés sociaux, et l'identification distinctive éventuelle des habitants de la ville du Cap par rapport au reste de l'Afrique du Sud. Dans la deuxième partie, je m'intéresse à la dimension diasporique de la communauté polonaise au Cap. A cette fin, j'examine les structures qui constituent l'une des facettes des Polonais du Cap : les organisations soumises à des processus de diasporisation. Elles ne sont pas à confondre avec les phénomènes de l'activité informelle, l'objet de l'analyse de la partie suivante. Dans la troisième partie, j'étudie la notion d'identité en général et, plus particulièrement, la question de l'identification à la nation polonaise. En donnant des exemples hors du contexte de la vie associative polonaise du Cap, je m'interroge sur : l'influence du contexte multiculturel de la société d'accueil sur l'identification des migrants polonais, l'approche dynamique de la présence des « traits » censées caractériser la nation polonaise au sein de la collectivité polonaise du Cap, et le processus de la transmission de l'identification nationale entre les générations. Dans mes résultats, je présente non seulement les différents types d'attachement au pays d'origine observés chez les acteurs sociaux, mais j'essaie également de tracer l'avenir possible du processus d'identification nationale chez les Polonais de mon terrain de recherche. J'espère que cette thèse constituera un point de départ pour d'autres chercheurs qui s'intéresseront à cette collectivité si méconnue, mais aussi pour des recherches comparatives sur l'identification nationale au sein d'autres communautés de migrants polonais. En tenant compte du fait que l'identité nationale en Pologne est en pleine transition, l'analyse des différences identitaires entre les vagues migratoires du Cap peut également s'avérer utile dans les recherches comparatives avec l'identification des Polonais vivant en Pologne. / Within the Polish scientific community, few studies refer to South Africa and the Polish communities living in this place. However, this territory constitutes a unique social laboratory and Poles from South Africa are subject to phenomena that can hold the attention of sociologists. This research applies to pinpoint the identity dimension of these dynamic phenomena with the example of the three migratory waves of Poles living in the city of Cape Town. By combining qualitative techniques of social science research and the tradition of collecting data elaborated at the Chicago School, I present the evolution of attachment to the country of origin, as well as different types of plural identity. The first part is devoted to the historical and sociological presentation of my research field: South Africa in general, but also the peculiarities of the Cape region. This contextualization includes: the spatial organization of Cape Town, the inter-ethnic issues in the post-apartheid reality, the urban consequences of social prejudice, and the possible identification of the inhabitants of Cape Town distinctive from the rest of South Africa. In the second part, I put much interest in the diasporic dimension of the Polish community in Cape Town. To this end, I examine the structures which constitute one of facets of Polish people from Cape Town: the organizations subject to the process of diasporization. They are not to be confused with the phenomena of informal activity, the purpose of the analysis of the next section. In the third part, I study the notion of identity in general and, more specifically, the question of identification with the Polish nation. Giving examples out of context of the associative life of Polish people from Cape Town, I examine: the influence of the multicultural context of the host society on the identification of Polish migrants, the dynamic approach of the presence of " features" meant to characterize the Polish nation in the Polish community of Cape Town, and the process of transmitting national identification between generations. In my results, I present not only the different types of attachment to the country observed among social actors, but I also try to trace the possible future of the national identification process among Poles of my field research. I hope that this thesis will be a starting point for other researchers who might get interested in this community remained unrecognized, but also for comparative research on national identification within other Polish migrant communities. Taking into account that national identity in Poland is in transition, the analysis of identity differences between the migratory waves in Cape Town may also be useful in comparative research with the identification of Poles living in Poland.