Le bassin versant de l'Amazone est couvert par 5 % de plaines d'inondation. Quel est l'impact biogéochimique de ces zones sur les eaux du fleuve ? Le présent travail apporte un certain nombre de réponses à cette question, notamment en ce qui concerne la phase dissoute des eaux (<0,22µm) à travers l'étude de la plaine du lago Grande de Curuaí (Pará, Brésil). Notre étude s'est portée sur la nature et l'évolution des sédiments de la plaine en relation avec l'évolution de la phase dissoute des eaux dans les lacs de la plaine. Nous avons également identifié l'impact du compartiment végétal sur la chimie des eaux au sein de la várzea et quantifier les stocks d'éléments dans la végétation. L'établissement d'un modèle hydrologique nous a permis de représenter l'évolution temporelle de la várzea en termes de source, de stock et de mélange d'eau et d'éléments chimiques. Enfin, nous avons estimé l'impact des várzea, en termes de flux échangés avec l'Amazone. Il ressort de cette étude que les plaines d'inondation sont des milieux dynamiques en ce qui concerne les flux d'éléments et que leur impact sur la spéciation des éléments redox dans le milieu naturel est important. De plus elles jouent un rôle important sur la distribution temporelle des éléments échangés avec l'Amazone et sont par conséquent des milieux à prendre en compte dans les modèles de transfert entre le continent et l'Océan.

Thesis (Ph.D.)--University of Melbourne, School of Earth Sciences, 2007. / Typescript. Includes bibliographical references (leaves 197-215).

Thesis (Ph. D.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed July 19, 2007. Includes bibliographical references (p. 115-132).

Este trabalho é resultado de uma pesquisa realizada sobre a produção contemporânea de ciências sociais feita pelos intelectuais africanos, tendo como universo de estudo e ponto de partida a agência do Conselho para o Desenvolvimento da Pesquisa em Ciências Sociais em África CODESRIA uma instituição de caráter pan-africano fundada em 1973 com sede em Dakar, no Senegal. A tese parte da compreensão das motivações de fundação do CODESRIA e de seu modo de organização para em seguida refletir sobre as condições sociais de produção desse conhecimento, com enfoque especial na publicação, distribuição e acesso a essa produção. A observação realizada na 14ª Assembleia Geral do CODESRIA, evento de caráter científico e também administrativo, no qual são eleitos o seu corpo dirigente, é exposta neste trabalho. Os saberes endógenos do continente africano são alvo das reflexões dos cientistas sociais do continente, na busca pela construção de um paradigma africano nas ciências sociais. A tese discute essas reflexões e as possibilidades de construção de um conhecimento novo e/ou próprio do continente africano, tendo como base os pressupostos e métodos acadêmicos ocidentais. Neste campo, o confronto com o imaginário redutor construído pelo Ocidente sobre o continente africano é irrecusável. Examina-se, ainda, o modo como as cientistas sociais africanas desenvolvem o seu trabalho acrescentando novas perspectivas para as teorias feministas. O paradigma do desenvolvimento é outro tema crucial nas discussões dos cientistas sociais africanos e é abordado neste trabalho, a partir de um olhar sobre as controvérsias existentes entre o modo de produção capitalista e o que é próprio das formações sociais africanas. Este trabalho apresenta também uma discussão sobre a obra e os temas relacionados a dois autores em especial. O primeiro deles é Archie Mafeje, antropólogo negro sul-africano que foi nome importante nos debates desenvolvidos no CODESRIA até sua morte, em 1997. Mafeje realiza uma dura crítica à antropologia e seus pressupostos colonialistas, através do que ele denominou de ideologia do tribalismo. Examina-se como a antropologia beneficiou-se como disciplina dos conhecimentos adquiridos no continente africano, e acrescentam-se novos olhares para pensar a questão da identidade social e da etnicidade no continente africano. Por fim, aborda-se a produção e a trajetória de Achille Mbembe, cientista político dos Camarões que é um dos nomes contemporâneos de maior repercussão entre os cientistas sociais africanos. Achille Mbembe foi secretário executivo do CODESRIA, um posto crucial no direcionamento da instituição, e sua passagem pelo Conselho suscitou controvérsias de caráter administrativo, mas especialmente de posições teóricas, com parte considerável da comunidade de cientistas sociais que compõem o CODESRIA. / This work is the result of a survey on contemporary production of social sciences made by African intellectuals, with the universe study and its starting point at the Council for the Development of Social Science Research in Africa CODESRIA a pan-African institution founded in 1973 with headquarters in Dakar, Senegal. The thesis starts at the understanding of the founding motivations CODESRIA and its organization in order to then reflect on the social conditions of production of knowledge, with a special focus on publishing, distribution and access to this production. The observation made in the 14th CODESRIA General Assembly scientific event and also administrative, which are elected its governing body, is exposed in this work. Endogenous knowledge of the African continent are targeted by the reflections of social scientists of the continent, in the search for the construction of an African paradigm in the social sciences. The thesis discusses these reflections and the possibilities for building new knowledge and/or own the African continent, based on the Western academic assumptions and methods. In this field, the confrontation with the imaginary gear built by the West on Africa is undeniable. It examines also how African women social scientists develop their work adding new perspectives for feminist theories. The paradigm of development is another crucial issue in discussions of African social scientists and is covered in this work, from a look at the controversies between the capitalist mode of production and what is own of African social formations. This paper also presents a discussion of the work and issues related to two authors in particular. The first is Archie Mafeje, black South African anthropologist who was an important name in the debates developed in CODESRIA until his death in 1997. Mafeje performs a tough critique of anthropology and its colonialist assumptions, through what he called tribalism ideology. Examines how anthropology benefited as a discipline of knowledge acquired in Africa, and adds up new perspectives to think about the issue of social identity and ethnicity in Africa. Finally, deals with the production and the path of Achille Mbembe, a political scientist from Cameroon that is one of the contemporary names greater impact among African social scientists. Achille Mbembe was Executive Secretary of CODESRIA, a crucial post in the direction of the institution, and its passage through the Council raised administrative character of controversy, but especially of theoretical positions, with considerable part of the community social scientists that make up the CODESRIA.

D.Phil. / The amalgamation of SW Gondwana after the break-up of Rodinia supercontinent during the Neoproterozoic-early Palaeozic was one of the most active tectonic periods of the earth history and its geological evolution remains controversial. Recently, diverse hypotheses such as mantle plume activity, orthogonal continent-continent and strike-slip collisions according to different models try to explain the complex evolution of the Pan-African Brasiliano orogens and the associated sedimentary basins. In order to get insight of the SW Gondwana reconstruction, provenance analyses were performed on two Neoproterozoic-early Palaeozic sedimentary units: (1) the Arroyo del Soldado Group representing a —5000 meter thick platform succession unconformably overlying the mainly Archaean to Neoproterozoic rocks of the Rio de la Plata Craton in Uruguay and, (2) the Nama Group, a —2000 meter thick shallow marine to fluvial deposit interpreted as a foreland basin in response to tectonism in the adjacent northern Damara and western Gariep Orogenic Belts and unconformably overlying the mainly Mesoproterozoic rocks of the Kalahari Craton in Namibia. Several techniques including petrography, heavy mineral analysis, geochemistry, Sm-Nd isotope analysis and zircon dating were applied to both sedimentary basins. The petrographic, heavy mineral analyses and geochemical results from the Nama Group indicate a recycled upper crust composition characterized by metamorphic and granitic sources and minor mafic rocks. Palaeocurrent analyses of the chromian spinet bearing sandstones of the Nama Basin point to a volcanic island arc source located in the Damara Belt. Detrital zircon dating of the Nama Group display major peaks of Neoproterozoic and Mesoproterozoic ages suggesting a provenance from the Damara/Gariep Belts and their basements. Palaeocurrents from the west and the dominance of Neoproterozoic-Cambrian detrital zircon ages (76%) in the "Molasse" stage of the foreland evolution probably indicate exhumation of the felsic volcanic arc root which probably occurred after the time indicated by the younger zircon dated at 531 ±9 Ma. The petrographic and geochemical results from the Arroyo del Soldado Group indicate a recycled upper crust composition characterized by source diversity composed of granite-gneissic and mafic-metamorphic rocks. On average, Nd isotopes account for negative ENd values and TDM ages in a range of variation found elsewhere within SW Gondwana. Detrital zircon dating indicate sources dominated by Palaeoproterozoic (1.7-2.0-2.2 Ga) and subordinate Archaean ages (2.5-2.9-3.5 Ga). The scarcity of Mesoproterozoic and Neoproterozoic zircons and palaeocurrent directions towards the east indicate that the Arroyo del Soldado Group was fed by detritus from the Rio de la Plata Craton favouring a passive margin tectonic setting for their deposition. Deformation of the Arroyo del Soldado Group took place ca. 530 Ma, after strike-slip collision with an African affinity terrane. Finally, based on the palaeogeographic evaluation, the provenance of Nama foreland basin and the passive margin deposit of the Arroyo del Soldado basin suggest that continent-continent collision of the Kalahari/Congo Cratons with the Rio de la Plata Craton and the Cuchilla Dionisio Pelotas Terrane most likely occurred due to strike slip accretion related to a component of N—S shortening in the period between 530 and 495 Ma.

Masters of Science / Invasive pneumococcal disease (IPD), which includes potentially fatal conditions such as meningitis, septicaemia and pneumonia poses a threat in children aged <5 years, pneumonia being the leading cause of child mortality worldwide. Even though capsular polysaccharides are the main antigens involved in the immunity to encapsulated bacteria, it was found that in children in that age group, the immune system was unresponsive. Conjugate vaccines however induce immunologic memory and provide long-term protective immunity. Therefore the aim of this project was to develop novel conjugation strategies towards a pneumococcal conjugate vaccines and focuses mainly on the serotypes that are a burden to the African continent. The chemistry involved in developing a conjugate vaccine is of importance beacuse while some polysaccharides contain chemical grouping which can be conveniently utilized for conjugation, many medically important ones require derivatization before they can be coupled to protein. Derivatization of which can be achieved through various strategies, important to note is through hypervalent iodine oxidants. Two hypervalent iodine reagents, O-Methyl substituted-1-hydroxy-1,2-benziodoxol-3(1H)-one 1-oxide (Me-IBX)and modified 1-hydroxy-1,2-benziodoxol-3(1H)-one 1-oxide (mIBX)were successfully synthesized in preparation for the use in polysaccharide, polyribitol phosphate, (PRP) oxidation. The polysaccharide to be oxidised was first size reduced by microfluidisation to allow maximum oxidation. However, the extent to which oxidisation was achieved was not enough to conjugate the polysaccharide to the protein of preference, Bovine Serum Albumin, (BSA).

Afin de comprendre, caractériser et prédire l’évolution des cycles biogéochimiques océaniques face au changement climatique global, il est nécessaire d’appréhender au mieux la dynamique de la matière organique (MO) au niveau des interfaces « terre/océan ». Dans ce contexte, l’objectif général de cette thèse était d’améliorer les connaissances sur la dynamique de la fraction dissoute chromophorique de la MO (CDOM) des eaux de surface côtières méditerranéennes et arctiques, et d’en déterminer l’impact sur l’atténuation du rayonnement UV (UVR) et visible (PAR) sous-marin. Pour cela, l’étude des propriétés optiques d’absorbance et de fluorescence de la CDOM, couplée à des mesures radiométriques atmosphériques et sous-marines, ont été réalisées lors d’un cycle saisonnier en Baie de Marseille (station SOFCOM), et lors d’une mission océanographique en Mer de Beaufort durant l’été 2009. La Baie de Marseille est caractérisée par des quantités de CDOM faibles (aCDOM(350) = 0,10 ± 0,02 m-1), particulièrement à la fin de la période estivale de stratification, à cause de l’intensité de l’éclairement solaire, enrichi en UVR-B, qui dégrade et blanchie cette CDOM (SCDOM = 0,023 ± 0,003 nm-1). Dans cette zone côtière fortement urbanisée, la dynamique de la CDOM est pilotée par des processus biotiques (production biologique in situ et induite par les intrusions épisodiques du panache du Rhône) et abiotiques (photo-blanchiment et brassage). La CDOM est essentiellement d’origine autochtone, même lors d’événements d’intrusion du panache du Rhône (photo-dégradation de la CDOM terrestre durant son transit). Lors des périodes d’efflorescences algales, la CDOM se compose principalement de matériel récent, de type protéique (pic T), qui absorbe préférentiellement les courts UVR. Ces pulses de CDOM récente se superposent à un persistent signal de fond de CDOM composé majoritairement de matériel âgé, de type humique (pics M et C), qui absorbe les UVR et également le PAR. Au niveau du plateau Canadien de la Mer de Beaufort, la CDOM est très abondante (aCDOMmax(350) = 6,36 m-1), fortement influencée par les apports allochtones du Mackenzie (pics A-C et M) et décroit de manière conservatrice avec la salinité. Dans les eaux marines (salinité >25), la CDOM, qui présente de plus faibles concentrations (aCDOM(350) = 0,21 ± 0,13 m-1), provient d’une production biologique in situ récente favorisée par des upwellings ainsi que d’injections de CDOM (pics B-T et M) lors de la formation/fonte de la glace de mer. Etonnamment, la source principale du composé « humique marin » (pic M) n’est pas autochtone. Elle est issue d’apports allochtones provenant du Mackenzie. Celui-ci draine en effet de nombreux lacs qui sont le siège d’une intense activité biologique, et il est proposé dans cette thèse que les macrophytes qui s’y développent seraient à l’origine du pic M. Cette source de CDOM biologique allochtone, couplée aux processus de photo-blanchiment et d’absorption sur les particules de la CDOM terrestre, pourraient expliquer les valeurs élevées de SCDOM (&#8776; 0,020 nm-1) du Mackenzie en été. / To understand, characterize, and predict the evolution of oceanic biogeochemical cycles in relation to the global climate change, it is necessary to better understand the dynamics of organic matter (OM). In this context, the overall objective of this thesis was to get more insights chromophoric dissolved fraction of OM (CDOM) dynamics in surface Mediterranean and Arctic coastal waters and to determine the impact on attenuation of ultraviolet (UVR) and visible (PAR) underwater radiation. For this, the study of optical properties of absorbance and fluorescence of CDOM, coupled with atmospheric and underwater radiometric measurements, were made during a seasonal cycle in the Bay of Marseille (SOFCOM station), and in the Beaufort Sea during summer 2009. The Bay of Marseilles is characterized by low amounts of CDOM (aCDOM(350) = 0.10 ± 0.02 m-1), particularly in end summer stratification period due to the intensity of the solar irradiance, enriched in UVR-B, which degrades and bleaches CDOM (SCDOM = 0.023 ± 0.003 nm-1). In this highly urbanized coastal area, the dynamics of CDOM are driven by biotic processes (in situ biological production and within the Rhône River plume) and abiotic (photo-bleaching and mixing). Our results showed that CDOM is mostly of autochthonous origin, even during Rhône plume intrusion events (photo-degradation of terrestrial CDOM during the transit). During bloom periods, the CDOM consists mainly of a recent type protein (peak T), which preferentially absorbs in the short UVR. These pulses of recent CDOM are superimposed on a persistent background of CDOM mainly composed of aged material, humic-type (peaks M and C), which absorbs UVR and PAR. Over the Canadian shelf of the Beaufort Sea, CDOM is highly abundant (aCDOMmax (350) = 6.36 m-1) and strongly influenced by allochthonous inputs from the Mackenzie (peaks A-C and M) decreasing conservatively with salinity. In marine waters (salinity> 25), CDOM had lower concentrations (aCDOM(350) = 0.21 ± 0.13 m-1) and originated from a recent in situ biological production favored by upwelling and brine injections (peaks B-T and M). Surprisingly, the main source of the marine humic-like component (peak M) was not autochthonous. This material originates from allochthonous inputs from the Mackenzie River, which traverses numerous lakes where intense biological activity occurs. We suggest that this activity is mainly due to the macrophytes development, which may in part explain the origin of the peak M. This source of organic allochthonous CDOM coupled to other processes such as photobleaching and absorption on the particles of terrestrial CDOM, could explain the high values of SCDOM (&#8776; 0.020 nm-1) recorded in the Mackenzie during summertime.

This cross-sectional exploratory mixed methods study surveyed individuals across the African continent who identified themselves as music therapists, music therapy students, musicians who framed their work as “therapeutic,” and any practitioner who framed (part or all of) their practice as “music therapy” or “therapeutic musicing.” A questionnaire was distributed electronically to various groups and networks of people working in such capacities on the African continent. Twenty-two respondents comprised the final sample from 11 countries across all five of Africa’s geographical regions (North, South, East, West, and Central Africa). Qualitative data were coded and analyzed via content analysis. Quantitative data were analyzed via descriptive statistical analysis. The respondents were categorized into three practitioner types: Music Therapists within Accredited Guidelines (MTAGs), Self-identified Music Therapists (SIMTs) and Therapeutic Integrative Music Practitioners (TIMPs). These individuals described their professional identities, their practices, the contexts of their work, and the intended purposes of their work in diverse ways. They also described the role and use of music in their work. Results indicated that in every geographical region of Africa, a therapeutic music practitioner exists and is working actively with communities to bring health, wellness, and positive change. They describe their work differently, exist in different contexts, perceive and define music therapy and the therapeutic use of music in different ways, however, the three types of practitioners, or the “trifecta,” present overlapping interconnectedness and are rooted in similar objectives, philosophies, values, and desires regardless of location, clientele, or whether these individuals were connected or had interacted. A strong interest was expressed among participants for collaborating and connecting with one another or with other like-minded practitioners if avenues become available to do so. This is the first survey of diverse music therapy and therapeutic musicing practices in Africa and offers the first step towards mapping the scope of these practices on the continent and contributes towards creating a network of practitioners. The small sample size of this exploratory study invite future researchers to continue investigating this topic further. / Mini Dissertation (MMus (Music Therapy))--University of Pretoria, 2021. / Music / MMus (Music Therapy) / Unrestricted

Coral terrace surveys and U-series ages of coral and mollusk shells yield a surface uplift rate of ~0.6 m/ka for Kisar Island. The small island is located NE of Timor in the active Banda Arc of Indonesia. Based on this rate, Kisar first emerged from the ocean as recently as ~450 ka. Terrace surveys show warping that follows a pattern of east-west striking folds, which are along strike of thrust-related folds of similar wavelength imaged by a seismic reflection profile just offshore. This deformation shows that the emergence of Kisar can be attributed to forearc closure along the south-dipping Kisar Thrust. Terrace morphology and coral ages are best explained by recognizing major terraces as mostly growth terraces and minor terraces as mostly erosional into older growth terraces. All reliable and referable coral U-series ages are marine isotope stage (MIS) 5e (118-128 ka), which encrusted the coast up to 60 m elevation. All coral samples are found below 6 m elevation, but a tridacna (giant clam) shell in growth position at 95 m elevation yields an age of 195 +/- 31 ka, which corresponds to MIS Stage 7. Loose deposits of coral fragments found on top of low terraces between 8 and 20 m elevation yield ages of < 100 years and may represent paleotsunami deposits from previously undocumented seismic activity in the region. The metamorphic rocks of Kisar, Indonesia, which correlate with the Aileu Metamorphic Complex of East Timor, record the breakup of a supercontinent with associated rifting, metamorphism from arc-continent collision, and the growth and exhumation of a new orogenic belt. The protoliths of these rocks are mostly psammitic with minor basaltic and felsic igneous rocks. Geochemical analyses of mafic meta-igneous rocks show rift affinities that are likely related to rifting of Gondwana and later breakup in the Jurassic Period. The Aileu Complex is overlain by younger sedimentary rocks deposited on the northern passive margin of Australia, which collided with the Banda Arc in latest Miocene time. This collision caused metamorphism of the distal edge of the continental margin rocks at conditions of 600-700°C at 6-8 kbar and up to 700-850°C at 8-9 kbar locally, corresponding to depths from 25 to 30 km. These rocks were then rapidly uplifted and exhumed. U-Pb analysis of detrital zircons indicates a Permian to Late Jurassic age of the sedimentary sources and confirm an Australian provenance. The timing of metamorphism of the Aileu Complex is poorly constrained by previous studies, of which only a white mica cooling age of 5.36 +/- 0.05 Ma proved reliable. Prior apatite fission track studies show that all tracks are partially to completely annealed suggesting recent rapid cooling. A domal geometry of the island above the sea floor is expressed in the pinnacle shape. Foliations on Kisar Island generally strike parallel to the coastline, which is may be suggestive of doming. The Kisar Thrust, which is imaged in offshore seismic reflection data, may indicate that the doming corresponds to diapirism into the hinge of an active thrust-related anticline or diapirism of buoyant continental material along the thrust itself.

No description available.