Cette thèse s'inscrit dans le champ de la linguistique classique. Elle aborde l'étude du fonctionnement syntaxique du préverbe i en créole réunionnais. Un inventaire précis de ses emplois d'un point de vue descriptif est fait afin de déterminer ses conditions d'apparition et les conditions où il n'apparaît pas. Deux grandes catégories d'hypothèses sont confrontées : les hypothèses à base sémantique et les hypothèses à base purement syntaxique. Il s'agit de démontrer le bien-fondé de la seconde approche et les point faibles de la première. Les théories déjà publiées sur le problème du i sont examinées. Pour mieux saisir la valeur du i réunionnais, une comparaison des structures des créoles à base lexicale française est réalisée : le créole réunionnais qui est au premier plan de notre recherche ; les créoles mauricien et seychellois de la région de l'océan Indien et les créoles martiniquais, guadeloupéen et haïtien de la région de l'océan Atlantique. / This thesis is part of the field of classical linguistics. It deals with the study of the syntactic functioning of the preverb i in Reunion creole. A precise inventory of its uses from a descriptive point of view is made in order to determine its conditions of appearance and the conditions in which it does not appear. Two major categories of hypotheses are confronted: seamantic-based hypotheses and purely syntactical hypotheses. This is to demonstrate the merits of the second approach and the weak points of the first. Already published theories on the problem of i are examined. To better understand the value of Reunionese i, a comparaison of the structures of French-based creole languages is carried out: Reunion creole which is at the forefront of our reseach; Mauritian and Seychellois Creoles in Indian ocean region and Martinican, Guadeloupe and Haitian creoles of the Atlantic ocean region

La leptospirose est une zoonose d’importance médicale majeure dans les îles du Sud-Ouest de l’Océan Indien (SOOI) dont certaines enregistrent des incidences parmi les plus élevées au monde. Durant la dernière décennie, les données épidémiologiques moléculaires obtenues avec une approche « One Health » ont mis en évidence une grande diversité de lignées de leptospires ainsi que différentes chaines de transmission sur les différentes îles de la région. Les données moléculaires montrent la présence de leptospires pathogènes et de réservoirs animaux introduits ou endémiques de cette région. La distribution de ces différentes lignées de leptospires est associée à (i) un contraste épidémiologique incluant des différences dans la sévérité des cas humains et (ii) des niveaux de spécificité d’hôtes différents selon les leptospires considérés. Plus particulièrement, les leptospires endémiques du SOOI semblent être moins pathogènes chez les humains et montrent une plus forte affinité pour leur réservoir que les leptospires cosmopolites. Pour compléter nos connaissances sur l’histoire évolutive des leptospires du SOOI, nous avons produit des données provenant de chauves-souris de l’Afrique de l’Est. Ces données confirment la spécificité de certaines lignées de leptospires envers leurs hôtes chiroptères et suggèrent que les chauves-souris d’Afrique ont colonisé Madagascar tout en étant infectées par leurs leptospires. Afin de mieux comprendre le rôle des différents leptospires dans l’épidémiologie régionale de la leptospirose, nous avons mesuré la pathogénicité de trois souches de leptospires retrouvées dans cette région à l’aide d’un modèle hamster. Des souches de Leptospira mayottensis et Leptospira borgpetersenii ont été isolés respectivement de Tenrec ecaudatus (tenrec) et Triaenops menamena (chauve-souris), deux mammifères endémiques du SOOI. Une souche de Leptospira interrogans, dont le génotype est retrouvé dans la majorité des cas humains graves à la Réunion, a été isolée de Rattus rattus (rat). En cohérence avec les données épidémiologiques humaines de Mayotte et de La Réunion, les leptospires endémiques se sont révélées être significativement moins pathogènes que la souche L. interrogans. La spécificité d’hôte des deux souches isolées de mammifères endémiques a été mise à l’épreuve par des infections expérimentales de Rattus norvegicus, connu comme un réservoir important de leptospires. Les rats ont été infectés avec les trois isolats précédemment utilisés. Les rats infectés par les souches endémiques n’ont pas développé d’infection rénale chronique contrairement à la souche cosmopolite. Ces résultats montrent que la spécificité d’hôte des leptospires endémiques observée in natura est probablement due à des facteurs génétiques plutôt qu’à des facteurs écologiques, comme un manque de contacts physiques entre les réservoirs animaux endémiques et introduits. Enfin, le séquençage complet de souches de leptospires du SOOI a été réalisé afin d’identifier des caractéristiques génétiques pouvant être associées à la pathogénicité et la spécificité d’hôte des leptospires pathogènes. Une classification précise de souches de leptospires du SOOI a pu être réalisée sur la base des génomes complets. La comparaison de ces génomes a permis d’identifier des gènes spécifiques à un groupe ou une espèce de leptospires. Cependant des modifications génomiques complexes rendent difficiles l’identification de caractéristiques génomiques responsables d’un phénotype particulier tel que la virulence ou la spécificité d’hôte. / Leptospirosis is a zoonosis of main medical concern on several islands of southwestern Indian Ocean (SWIO), some of which recording among the highest human incidence worldwide. Over the last decade, molecular epidemiology investigations carried out under a One Health framework have revealed a wide variety of Leptospira lineages and distinct transmission chains throughout the islands of the region. These islands are home to pathogenic Leptospira lineages and animal reservoirs that are either introduced or endemic to the SWIO region. Interestingly, the regional distribution of Leptospira diversity is associated with (i) a contrasted severity of human cases and (ii) distinct levels of specificity of Leptospira towards their mammalian hosts. Specifically, endemic Leptospira appear less pathogenic in humans and display higher specificity towards their animal reservoirs than their cosmopolitan counterparts. To complete the dataset of Leptospira diversity in the SWIO region, we produced data from bats of eastern Africa. Results support the previously observed pattern of host specificity of Leptospira towards their bats hosts and, overlaid upon the biogeographic history of Malagasy bats, suggest that these volant mammals have colonized Madagascar from continental Africa while hosting pathogenic Leptospira. To better understand the role of distinct Leptospira lineages in the contrasted epidemiology observed in the SWIO, we investigated the pathogenicity of three Leptospira isolates from this region using a hamster model. Leptospira mayottensis and Leptospira borgpetersenii isolates were obtained from Tenrec ecaudatus (tenrec) on Mayotte and Triaenops menamena (bat) in Madagascar, respectively, both mammals endemic to the SWIO region. A Leptospira interrogans strain, which genotype has been reported in the majority of human acute cases on La Réunion, was isolated from the introduced Rattus rattus (rat). In keeping with a distinct severity of the disease on Mayotte and La Réunion, endemic bat-borne and tenrec-borne Leptospira were significantly less pathogenic than the control cosmopolitan rat-borne isolate. The host specificity of the isolates obtained from endemic hosts was addressed using experimental infection of Rattus norvegicus, a known reservoir of pathogenic Leptospira. This animal model was challenged with all three isolates and mostly failed in supporting chronic infection with bat-borne and tenrec-borne Leptospira. Hence, the strong host-specificity of endemic Leptospira toward their hosts observed in the wild likely results from genetic determinants shaped by long-term co-evolutionary processes rather than from ecological constraints such as a lack of physical contact between introduced and endemic animal reservoirs. Finally, we undertook full genome sequencing of regional strains in order to highlight genomic features that may be associated with virulence and host specificity. Whole genome sequencing allowed the accurate classification of Leptospira isolates obtained on SWIO islands. Comparative genomics allowed to identify genes specific to a group or species of Leptospira but complex changes in Leptospira genome make difficult the identification of genomic elements responsible for specific traits such as virulence and host specificity.

A massive tsunami hit Aceh in December 26, 2004. It was one of the biggest natural disasters of the century. The tsunami’s unprecedented destruction of the area attracted the biggest influx ever of international aid and highlighted the nearly non-existent social service system at local levels. The abundance of international aid served as an impetus for the Indonesian government to review their social service system. This is the first time that resources from international aid in Indonesia were allocated for professionalization of social workers. This dissertation utilizes a qualitative narrative analysis to explore the questions: How do Indonesian social workers understand and express their experience of the social work professionalization process post-2004 tsunami? How do they interpret the process of professionalization? How do the systems available influence their professional interpretation of the experience and affect their strategies to gain public recognition and resources to claim professional jurisdiction in a society? Interviews were conducted of fifteen Indonesian social workers who were involved in the 2004 tsunami recovery efforts and are still active in the social work professionalization efforts today. The findings show that the international aid and 2004 tsunami in Aceh, Indonesia was the impetus for professionalization of social work in Indonesia. This study explores how Indonesian social workers understand and interpret their experience during the tsunami 2004 recovery efforts using Abbott’s system of professions concepts to frame the professionalization process as impacted by international aid during the 2004 tsunami. The findings revolve around formal public recognition, community sanction and a systematic knowledge base in Indonesia’s social work professionalization process.

La grande majorité des colorants alimentaires naturels, utilisés dans la formulation des aliments et des boissons, proviennent des pigments extraits de matières premières végétales. Plusieurs couleurs dérivées de plantes peuvent entraîner des problèmes de formulation. Des facteurs, comme par exemple, la région, le climat, l'environnement, la variété cultivée, ont un effet de nuances de couleurs, de résistance et surtout de stabilité dans le produit final. Par ailleurs, les champignons filamenteux du genre Monascus, Penicillium et Talaromyces sont connus comme d'excellents producteurs de pigments rouges. Ces pigments intéressent de ce fait les industries car ils sont stables, non-toxiques et peuvent être utilisés comme colorants alimentaires.La recherche présentée dans le cadre de cette thèse de doctorat concerne la description des propriétés du pigment rouge que produit la souche de Talaromyces albobiverticillius isolée du milieu marin tropical autour de l'île de La Réunion. Les plans d’expérience (DOE) et la méthodologie des surfaces de réponses (RSM) ont été utilisés pour optimiser les conditions de culture et la formulation du milieu de fermentation, dans le but d'accroître les teneurs en polykétides colorés. Douze structures différentes ont été identifiées dans des extraits intracellulaires et extracellulaires des cultures fongiques, à l'aide de séparations et d'analyses spectroscopiques (HPLC-PDA-ESI/MS et RMN). Les pigments N-thréonine-monascorubramine, N-glutaryl-rubropunctamine et PP-O figurent ainsi parmi les 12 composants.Avec la demande croissante de composés colorés naturels dans le secteur industriel, les champignons isolés du milieu marin semblent présenter de nombreux intérêts. Des essais ont ainsi été menés afin d'étudier 1) l'amélioration des conditions de fermentation en fioles agitées ou en fermenteur de 2 litres; 2) les effets de la teneur en sel marin sur la synthèse des pigments; 3) des méthodes d'extraction respectueuses de l'environnement. Globalement, ces résultats font ressortir le grand potentiel des champignons marins produisant ce colorant rouge et la possibilité d'obtenir les colorants alimentaires adaptés. / It is well known that the vast majority of food colorants used in food and beverage applications comes from the pigments synthesized by plant materials. Besides, stability of many plant-derived colors can create formulation problems. Factors such as the region, the climate, the environment, the cultivar all impact colors shade, strength and overall stability in the final product. As an alternate, fungi of the genus Monascus, Penicillium and Talaromyces are known as excellent producers of red pigments. These red pigments are of industrial interest as they are stable and non-toxic and can be used as food colorants.This present research deals with the selection of high throughput red pigment producing Talaromyces albobiverticillius as a source of polyketide based natural food colorants. Design of Experiments (DoE) and Response Surface Methodology (RSM) have been used to optimize culture conditions and media formulation of fermentation process. Using Box Behnken Design (BBD), the influence of different physical factors on pigment and biomass production was studied using potato dextrose broth as culture media. The best optimal conditions were found to be with initial pH of 6.4, temperature of 24 °C, agitation speed of 164 rpm and fermentation time of 149 h gave 47.93 ± 0.58 mg /L of orange pigment, 196.28 ± 0.76 mg / L of red pigment and 12.58 ± 0.41 g /L of dry biomass. With the application of Plackett- Burman Design (PBD), 16 different media formulations were optimized using various carbon and nitrogen sources. When Sucrose and Yeast extract was used as a basal medium at 24° C, high pigment yield was observed: 695.93 ± 0.29 mg /L of orange pigment, 738.28 ± 0.51 mg / L of red pigment and 6.80 ± 0.37 g /L of dry biomass.Twelve different compounds were detected from the HPLC-PDA-ESI/MS analysis of intracellular and extracellular pigmented extracts. In particular, N-threonine-monascorubramine, N-glutaryl-rubropunctamine and PP-O were tentatively identified among these twelve compounds; further, this work reports for the first time on the PDA, MS and NMR characterization of the here named as N-GABA-monascorubramine derivative (6-[(Z)-2-Carboxyvinyl]-N-GABA-monascorubramine) pigment bearing a cis configuration at the C10-C11 double bond, in Talaromyces albobiverticillius 30548. Attempts were made to study the effects of sea salts on pigment synthesis; sustainable green extraction methods for pigments; upscaling of fermentation from shake flasks to laboratory fermenter. All these experiments with their results were discussed briefly as individual chapters. Overall, these findings bring out the potential of marine-derived red pigment producing fungi and its possibility of obtaining tailor made food colorants.

Le Golfe du Bengale (GdB), dans l'océan indien Nord, est sous l'influence d'intenses vents de mousson, qui se renversent saisonnièrement. Les fortes pluies et les apports fluviaux associés à la mousson de Sud-Ouest font du GdB l'une des régions les moins salées des océans tropicaux. La forte stratification haline proche de la surface qui en découle contribue à limiter le mélange vertical, ce qui maintient des températures de surface élevées et favorise la convection atmosphérique et les pluies. Cette stratification en sel a ainsi des implications profondes sur les échanges air-mer et sur le climat des pays riverains. L'objectif de ma thèse est d'améliorer la description de la variabilité de la salinité de surface (SSS) du GdB, et de comprendre ses mécanismes aux échelles de temps saisonnières à interannuelles. Les climatologies existantes ont permis de mettre en évidence un cycle saisonnier marqué de la SSS, avec un dessalement intense de la partie Nord du bassin pendant l'automne, suivi par une expansion de ces eaux dessalées le long du bord Ouest du bassin. Cette langue dessalée s'érode finalement pendant l'hiver, pour revenir à son extension minimale au printemps. Cependant, la rareté des observations in-situ de SSS ne permet d'observer les fluctuations interannuelles autour de ce cycle saisonnier que de manière parcellaire dans le GdB. Le développement récent de la télédétection spatiale de la SSS (missions SMOS et AQUARIUS) a ouvert de nouvelles opportunités à cet égard. Cette technologie reste toutefois délicate dans le cas d'un bassin de petite taille tel que le GdB, du fait des contaminations éventuelles du signal de SSS par les interférences radio et par les sources d'origine continentale. Une validation systématique des produits satellites par comparaison à un jeu de données in-situ exhaustif montre qu'Aquarius capture de façon réaliste les évolutions saisonnières et interannuelles de la SSS partout dans le GdB. A l'inverse, SMOS ne parvient pas à restituer une salinité meilleure que les climatologies existantes. / Located in the Northern Indian Ocean, the Bay of Bengal (BoB) is forced by intense seasonally reversing monsoon winds. Heavy rainfall and strong river runoffs associated with the southwest monsoon makes the bay one of the freshest regions in the tropical ocean. This surface fresh water flux induces strong near surface salinity stratification, which reduces vertical mixing and maintains high sea surface temperatures and deep atmospheric convection and rainfall. This intense near surface haline stratification has therefore profound implications on the air-sea exchanges, and on the climate of the neighboring countries. The goal of my thesis is to improve the description of the Sea surface salinity (SSS) variability in the BoB and to understand the oceanic and atmospheric processes driving this variability at seasonal and interannual timescales. Existing climatologies reveal a marked seasonal cycle of SSS with an intense freshening of the northern part of the basin during fall that subsequently spreads along the western boundary. This fresh pool finally erodes during winter, to reach its minimal extent in spring. The paucity of in-situ SSS observations however prevented to monitor the interannual fluctuations around this seasonal picture with a good spatial coverage. The recent development of SSS remote-sensing capabilities (with SMOS and AQUARIUS satellites) may help with that regard. However this is particularly challenging for a small semi-enclosed basin such as the Bay of Bengal, because of the potential contamination of the SSS signal by radio frequency interferences and land effects in the near coastal environment. A thorough validation of these satellite products to an exhaustive gridded in-situ dataset shows that Aquarius reasonably captures the large-scale observed seasonal and interannual SSS evolution everywhere in the BoB while SMOS does not perform better than existing climatologies, advocating for improvements of its SSS retrieval algorithm there.

[Truncated abstract] In March 2005, the Indian Ocean island of Reunion, a former colony and now overseas department of France, saw the first cases of what was to become a massive epidemic of the mosquito borne viral infection Chikungunya. More than 250,000 people, one third of the Island's population, were subject to high fevers, rash, and joint and muscle pains over the next 18 months, yet the public health authorities in metropolitan France were arguably slow to take the epidemic seriously. The research presented here explores attitudes underlying the management of the epidemic by examining both metropolitan and local representations of mosquito borne disease from historical, epidemiological and media perspectives. The research seeks to answer the general question Does colonial history continue to influence the representation and management of mosquito borne disease in Reunion? Three parallel approaches are taken to answering this question, using a common framework of tropicality (a Western discourse that exalts the temperate world over its tropical counterpart, and overlaps with colonialism and orientalism). ... Several factors are likely to have contributed to the persistence of tropicality in public health practice in Reunion: Othering as a universal phenomenon; the cost of administering interventions to combat tropical diseases in the remote environments of French overseas departments and territories; the denial of a serious public health risk as a cultural trait in Reunion; and the significant role of the colonies in forming and maintaining the French national identity. It has to be acknowledged that historically, tropicalism does appear to have played one positive role in the management of mosquito borne disease:

The present study is one of the first attempts to analyze the societal importance of seagrasses (marine flowering plants) from a Natural Resource Management perspective, using a social-ecological systems (SES) approach. The interdisciplinary study takes place in East Africa (Western Indian Ocean, WIO) and includes in-depth studies in Chwaka Bay, Zanzibar, Tanzania. Natural and social sciences methods were used. The results are presented in six articles, showing that seagrass ecosystems are rich in seagrass species (13) and form an important part of the SES within the tropical seascape of the WIO. Seagrasses provide livelihoods opportunities and basic animal protein, in from of seagrass associated fish e.g. Siganidae and Scaridae. Research, management and education initiatives are, however, nearly non-existent. In Chwaka Bay, the goods and ecosystem services associated with the meadows and also appreciated by locals were fishing and collection grounds as well as substrate for seaweed cultivation. Seagrasses are used as medicines and fertilizers and associated with different beliefs and values. Dema (basket trap) fishery showed clear links to seagrass beds and provided the highest gross income per capita of all economic activities. All showing that the meadows provide social-ecological resilience. Drag-net fishery seems to damage the meadows. Two ecological studies show that artisanal seaweed farming of red algae, mainly done by women and pictured as sustainable in the WIO, has a thinning effect on seagrass beds, reduces associated macrofauna, affects sediments, changes fish catch composition and reduces diversity. Furthermore, it has a negative effect on i.a. women’s health. The two last papers are institutional analyses of the human-seagrass relationship. A broad approach was used to analyze regulative, normative and cultural-cognitive institutions. Cooperation and conflict take place between different institutions, interacting with their slow or fast moving characteristics, and are thus fundamental in directing the system into sustainable/unsustainable paths. Ecological knowledge was heterogeneous and situated. Due to the abundance of resources and high internal control, the SES seems to be entangled in a rigidity trap with the risk of falling into a poverty trap. Regulations were found insufficient to understand SES dynamics. “Well” designed organizational structures for management were found insufficient for “good” institutional performance. The dynamics between individuals embedded in different social and cultural structures showed to be crucial. Bwana Dikos, monitoring officials, placed in villages or landing sites in Zanzibar experienced four dilemmas – kinship, loyalty, poverty and control – which decrease efficiency and affect resilience. Mismatches between institutions themselves, and between institutions and cognitive capacities were identified. Some important practical implications are the need to include seagrass meadows in management and educational plans, addressing a seascape perspective, livelihood diversification, subsistence value, impacts, social-ecological resilience, and a broad institutional approach.

Using the case study of 21st century Piracy as it affects the small islands archipelagic state of the Seychelles, this paper sets the stage for a broader discussion on the sovereignty of small island states in international law. Sovereignty can be viewed through different lenses; sovereignty denied considers the many challenges faced by small island states and their claim to the traditional concept of sovereignty, as promoted during the decolonisation era and projected by the right of self determination. On the other hand sovereignty can also be yielded by small island states, where the jurisdiction of the state becomes a resource. This is demonstrated through the degree of international assistance afforded to the Seychelles in dealing with pirates and more generally, through the development of offshore companies in small island states. Consequently, this paper suggests that international law is both the problem and solution to the sovereignty of small island states.

Using the case study of 21st century Piracy as it affects the small islands archipelagic state of the Seychelles, this paper sets the stage for a broader discussion on the sovereignty of small island states in international law. Sovereignty can be viewed through different lenses; sovereignty denied considers the many challenges faced by small island states and their claim to the traditional concept of sovereignty, as promoted during the decolonisation era and projected by the right of self determination. On the other hand sovereignty can also be yielded by small island states, where the jurisdiction of the state becomes a resource. This is demonstrated through the degree of international assistance afforded to the Seychelles in dealing with pirates and more generally, through the development of offshore companies in small island states. Consequently, this paper suggests that international law is both the problem and solution to the sovereignty of small island states.

This thesis considers the use of two U-series nuclides – 231 Pa and 230 Th – as proxies for studying ocean circulation. A total of six water-column profiles of 231 Pa, 230 Th, and 232 Th have been measured from two regions of the southwestern Indian Ocean: the Madagascar and Mascarene Basins; and the southeastern continental margin of South Africa. Measurement by MC-ICP-MS of 10 litre water samples is possible for samples with as little as 4 and 2 fg of 231 Pa and 230 Th and yields typical uncertainties of 6% and 14% respectively. These profiles show that the scavenging and advection histories of water masses can affect their 231 Pa concentration, with distinct variations superimposed on a general increase in concentration with depth due to reversible scavenging. A 1D particle scavenging model is used to show that sedimentary (231 Paxs /230 Thxs )0 is most representative of the (231 Pa/230 Th) of the bottom most water mass at any one locality, although in turn this water mass (231 Pa/230 Th) will be dependent not only on its advection and scavenging history but also the 231 Pa and 230 Th concentrations of the overlying water masses during advection. Acknowledgment that sedimentary (231 Paxs /230 Thxs )0 is “set” by the bottommost water mass is important for interpretation of scenarios where changes in depth of circulation, as well as circulation strength, may have occurred. A record of sedimentary (231 Paxs /230 Thxs )0 has been recovered from a 6 m Kasten core from the Mascarene Basin covering the past 140 ka, in order to reconstruct flow of AABW into the basin. The (231 Paxs /230 Thxs )0 measured is below the production ration of 0.093 and shows no significant variation. This indicates that (231 Paxs /230 Thxs )0 is sensitive to changes in particle productivity and circulation at this location and that there has been little or no change in either environmental variable over the last full interglacial-glacial cycle. This finding is in contrast to other ocean basins, particularly the North Atlantic, where large changes in circulation are observed.