Considerando o crescente problema de saúde pública relacionado à dependência química em crack e à proliferação de locais conhecidos no Brasil como cracolândias, esta tese visa estudar o impacto do uso das tecnologias da informação e comunicação no processo de ressocialização, especificamente através do desenvolvimento de um exclusivo objeto de aprendizagem, aplicado em uma comunidade terapêutica, com um grupo de toxicômanos em álcool e drogas em vulnerabilidade social. O presente trabalho objetiva identificar se, ao manipularem tal software, os drogadictos são capazes de apontar alguma diferença significativa entre as características do modelo proposto, levando em consideração que sua interface foi construída com a apropriação de valores apontados como relevantes durante entrevistas, tanto pelos adictos em recuperação, quanto pelos demais profissionais, em uma investigação-piloto realizada no Rio Grande do Sul. Em São Paulo, após a construção do objeto de aprendizagem, construído no modelo OASIS – Objeto de Aprendizagem Significativa de Informação para Sociedade, durante diferentes meses e com um novo grupo de voluntários, foram propostas e testadas hipóteses relacionadas à percepção dos sujeitos sobre os elementos que compõem este objeto de aprendizagem. Por fim, espera-se que a experiência possa despertar novas pesquisas nesta temática para que a aplicação das orientações contidas na construção desse software possa ser expandida. / Given the growing public health problem related to crack addiction, and the proliferation of places known in Brazil as “Cracolândias”, this thesis proposes to study the impact of the use of information and communication technologies, specifically through the development of an exclusive learning object during the process of rehabilitation in a therapeutic community - a group of addicts in drug and alcohol in social vulnerability through training to work – making use of professional education videos. Thus, this study aims to determine if, when manipulating such software, drug addicts are able to point, or not, any significant difference between the characteristics of the proposed model, considering that its interface was built upon values considered relevant during the interviews, both by recovering addicts as well as by other professionals in a research pilot in Rio Grande do Sul. After construction of the learning object, the research continued in São Paulo for several months with a new group of volunteers. This research proposes and tests hypotheses related to the perception of the subjects on the elements that make up this learning object model built in OASIS - Significant Learning Objects for Information Society. Finally, it is expected that this experience may trigger new research related to this issue, in which the application of the guidelines contained in the construction of such software can be expanded.

Considerando o crescente problema de saúde pública relacionado à dependência química em crack e à proliferação de locais conhecidos no Brasil como cracolândias, esta tese visa estudar o impacto do uso das tecnologias da informação e comunicação no processo de ressocialização, especificamente através do desenvolvimento de um exclusivo objeto de aprendizagem, aplicado em uma comunidade terapêutica, com um grupo de toxicômanos em álcool e drogas em vulnerabilidade social. O presente trabalho objetiva identificar se, ao manipularem tal software, os drogadictos são capazes de apontar alguma diferença significativa entre as características do modelo proposto, levando em consideração que sua interface foi construída com a apropriação de valores apontados como relevantes durante entrevistas, tanto pelos adictos em recuperação, quanto pelos demais profissionais, em uma investigação-piloto realizada no Rio Grande do Sul. Em São Paulo, após a construção do objeto de aprendizagem, construído no modelo OASIS – Objeto de Aprendizagem Significativa de Informação para Sociedade, durante diferentes meses e com um novo grupo de voluntários, foram propostas e testadas hipóteses relacionadas à percepção dos sujeitos sobre os elementos que compõem este objeto de aprendizagem. Por fim, espera-se que a experiência possa despertar novas pesquisas nesta temática para que a aplicação das orientações contidas na construção desse software possa ser expandida. / Given the growing public health problem related to crack addiction, and the proliferation of places known in Brazil as “Cracolândias”, this thesis proposes to study the impact of the use of information and communication technologies, specifically through the development of an exclusive learning object during the process of rehabilitation in a therapeutic community - a group of addicts in drug and alcohol in social vulnerability through training to work – making use of professional education videos. Thus, this study aims to determine if, when manipulating such software, drug addicts are able to point, or not, any significant difference between the characteristics of the proposed model, considering that its interface was built upon values considered relevant during the interviews, both by recovering addicts as well as by other professionals in a research pilot in Rio Grande do Sul. After construction of the learning object, the research continued in São Paulo for several months with a new group of volunteers. This research proposes and tests hypotheses related to the perception of the subjects on the elements that make up this learning object model built in OASIS - Significant Learning Objects for Information Society. Finally, it is expected that this experience may trigger new research related to this issue, in which the application of the guidelines contained in the construction of such software can be expanded.

Cette thèse porte sur un espace oasien (une terre agricole encore en état de production) qui tend à s’urbaniser de manière informelle : l’oasis de Zrig, dans le Sud-est de Gabès, en Tunisie. L’habitat qui s’y développe prolifère sans permis de construire depuis 1980. Dans ce nouvel espace urbain se développe une double marginalisation sociale touchant aussi bien les paysans qui ont perdu leurs terres que les nouveaux venus aux ressources souvent précaires. L’environnement et le patrimoine agricole local en pâtissent également. Zrig est un détail (au sens pictural) du devenir de l’oasis de Gabès. Un travail de recherche sur l’espace de Zrig et ses transformations se rapproche de la chronique d’une dégradation annoncée. Il y a, en effet, dégradation à deux niveaux : la transformation d’un espace oasien en un espace urbain difforme et le développement de pratiques socio-économiques informelles liées aux stratégies des nouveaux arrivants et aux rapports qu'ils entretiennent avec les autorités locales.Ce travail s’appuie sur les résultats d’une enquête de longue haleine que j'ai effectuée de 2010 au 2016 auprès des habitants de Zrig, ceux d’hier et d’aujourd’hui, afin de recueillir leurs représentations des transformations spatiales et sociales qui ont affecté l’oasis. Il constitue également une étude des modes de construction de logements informels et une analyse des stratégies perpétuant cette pratique mise en œuvre par les nouveaux venus. / This dissertation relates to an oasis area (a still productive agricultural land) which is being informally urbanized: in the Zrig oasis, south-east of Gabes, the habitat has proliferated without building permit since 1980.In this new urban space, a double social marginalization affects farmers who lost their land as well as newcomers with often precarious resources. The environment and the local agricultural heritage are also impacted.Zrig is a detail (in apictorial sense) of the future of the Gabes oasis. A research work on the space of Zrig and its transformations resembles the chronicle of an announced degradation. Indeed, the degradation can be identified at two levels: the transformation of an oasis area into a deformed urban space, and the development of informal socio-economic practices related to the strategies of space occupants and to their relations with local authorities. In addition to the data provided by official and academic surveys, this work is based on the results of a long-term survey that I conducted from 2010 to 2016 Zrig, those of yesterday and those of today, in order to collect their representations of the spatial and social transformations that affected the oasis. But also to study the building practices of informal settlement sand the strategies of newcomers for this purpose.

Stable isotope analysis is often used to evaluate elements of the lives of past peoples, such as diet and health status, at a societal level. Analysis at an individual level is exceptionally rare, and has not been conducted using a variety of tissues representing both early life and life approximate to death. In this study, δ 13C and δ15N isotope signatures are used to create life histories for single individuals from Romano-Christian period Kellis 2 cemetery in the Dakhleh Oasis, Egypt. Samples are obtained from several different tissues, including tooth dentin, bone collagen, hair, nail, skin, and gut content, all of which have been previously researched, but have not been studied at such an individualistic level. By using data and previous research conducted by Drs. Tosha Dupras and Lana Williams, this research uses isotopic values from the aforementioned tissues, and the differing turnover rates of these tissues, to develop lifetime timetables for 15 individuals (female, male, and juvenile). Results show that individual analysis is possible, informative, and can enlighten researchers not just concerning the individual, but about the population as a whole. The methods presented can serve as a model for reconstructing individual life histories using isotope data from multiple tissues.

Use of paleohistology to identify histological structures in mummified tissues can allow insight into pathological conditions such as parasites, cirrhosis and lung scarring. However, increasing concerns in archaeological sciences include restrictions on removal of human remains from their site of origin for scientific study. In the case of mummified remains, the use of a field paleohistology kit may be deemed useful for ‘point-of-care’ pathological assessment of preserved tissues. This study evaluates field paleohistology protocols for mummified soft tissue based on techniques used modern medical field missions. The application of this technique alleviates the need for export or removal of remains from the site for analysis. Samples from the Kellis 1 Cemetery (c. 60BC – AD100) and Deir abu Metta Christian church (c. 4th century AD) in the Dakhleh Oasis, Egypt were processed using field paleohistology techniques in both a laboratory and field setting. Two processes of soft tissue preservation were identified in this sample; anthropogenic or ‘artificial’, and spontaneous or ‘natural’ mummification. In cases of artificial mummification, the use of resin, both on internal and external surfaces of the body, caused difficulty in the rehydration process and visualization of the cellular structures. In cases of natural mummification, the technique was more successful in rehydration, slide mounting, imaging, and detection of cellular structures. Results also showed some tissue samples to be unsuitable for this method due to variable preservation and loss of tissue integrity during processing (e.g., liver). However, consistent quality microscope slides and digital images were obtained from samples of skin, muscle, lung, and liver indicating this point-of-care field method is a viable option for paleohistological field analyses and identification of pathological conditions in mummified human remains.

S'engager dans le processus de mise en place de l'écotourisme dans les pays en voie de développement nécessite aujourd'hui, une réelle stratégie afin d'aider les décideurs à s'assurer de la durabilité des aménagements touristiques de leur territoire. Plus encore, s'agissant des espaces désertiques, il y a urgence à construire un modèle de mise en œuvre des projets écotouristiques applicables dans ces milieux vulnérables et basé sur le concept d'optimum écotouristique développé par Jean-Pierre LOZATO-GIOTART (2003, p.306) qui prône une synergie entre leurs différents composantes : intervenants, ressources (naturelles et culturelles), communautés locales et visiteurs… c'est-à-dire un "équilibre entre pratiques de loisirs et préservation des territoires d’accueil". La création d'une grille d'indicateurs d'écotourisme spécifique aux espaces désertiques est une approche qui pourrait aider à construire des programmes de développement selon les principes de l'optimum écotouristique. Aussi, l'application du concept de l'optimum écotouristique dans le sud-ouest du Sahara algérien, grâce au projet-pilote écotouristique à la Daïra de Charouine, située dans la wilaya d'Adrar, répond de façon appropriée aux stratégies de développement local des régions du Sud de l'Algérie, dont la grande majorité est cataloguée comme pauvres, bien que leurs richesses en biodiversité et culture aient déjà été recensées.Cette étude de cas ouvre une nouvelle vision sur la réflexion à mener à propos des indicateurs de durabilité en écotourisme en vue de leur application effective dans le contexte de planification et de gestion des projets dans les milieux désertiques. / Launching the process of establishing ecotourism in developing countries requires today a real strategy to help decision makers to ensure the sustainability of tourism development in their territory. Furthermore, with regard to desert areas, there is urgency to build a model of implementation of ecotourism projects applicable in these vulnerable areas and based on the concept of ecotourism optimum developed by Jean-Pierre Lozato-Giotart (2003, p.306) that promotes synergy between their different components: actors, resources (natural and cultural), and visitors local communities ... that is to say, a "balance between recreation and conservation practices of the host territories". Creating a grid of indicators specific to desert areas ecotourism is an approach that could help build development programs based on the principles of ecotourism optimum. Also, the application of the concept of ecotourism in the optimum southwest of the Algerian Sahara, through the pilot project of ecotourism in the Daïra Charouine, located in Adrar, responds appropriately to local development strategies of the southern regions of Algeria, the vast majority is classified as poor, although their wealth in biodiversity and culture has already been identified. This case study opens a new vision to carry on thinking about sustainability indicators ecotourism for their effective implementation in the context of planning and project management in desert environments.

Le Tafilalet est une région du Maroc Saharien située dans le secteur sud-est, dans une zone frontalière, elle présente les signes d’un espace désertique fragile et marginalisé. Sa situation géographique, ses traits climatiques et son profil morphologique en font un espace structurellement vulnérable, qui n’offre que peu de chances au développement humain et économique. Pourtant, c’est un espace qui a pu briller et voir une période d’essor durant le Moyen Age. Celle-ci a connu le développement d’une grande civilisation de l’aride, dont les traits sont encore vivants dans le système de production agropastoral oasien. Ces particularités avaient permis l’établissement d’un équilibre fragile entre l’homme oasien, ses besoins et sa demande et un milieu fragile avec peu de capacités. Un équilibre rompu, depuis, par la modernité, l’exode rural, l’urbanisation et la salarisation. Nouveau arrivé dans le système économique oasien, le tourisme s’est développé à partir du début du XXème siècle, et a enregistré une importante évolution au point de devenir la première activité économique structurée du territoire. Le désert, les dunes, la palmeraie sont les grands atouts de ce produit, qui essaie de combiner, avec l’offre originelle paysagère, une offre culturelle constituée du bâtit, de la richesse humaine et tribale tout autant que par la commercialisation du désert comme espace ludique (circuit quad, VTT…). C’est ainsi que son produit s’affranchit des spots classiques du désert (dunes et dromadaire) pour s’ouvrir à un tourisme diffus, qui explore l’arrière pays, puisant dans la multi-activité et le ludique, l’immersion dans la vie quotidienne saharienne, le partage et l’échange culturel entre touristes et habitants. L’espace de notre étude autant que le secteur saharien, en globalité, se développe touristiquement, mais dans l’anarchie et la spontanéité. Le tourisme peut se révéler comme un facteur de menace pour la nature oasienne, son paysage, ses capacités en terme d’eau et de terre et son système de production agropastoral, majoritairement, vivrier et traditionnel…La mise en tourisme devra donc être rationnelle et bien contrôlée. Le développement du tourisme au Tafilalet passerait d’abord par une stratégie de développement durable. La place de la région, de l’acteur local sont très importantes, à nos yeux. Le développement devra, en ce sens, être appréhendé dans/ et par le territoire, comme espace de vie et d’action, loin des visions sectorielles qui n’avaient fait que prévaloir les zones utiles et marginaliser une bonne partie du territoire saharien. Cette approche doit interpeller aussi les spécificités de l’espace à la fois au niveau géographique et humain et mettre au centre de ses préoccupations la contrainte naturelle autant que la fragilité et la vulnérabilité environnementales… Des éléments qui ne peuvent être dissociés de la grande problématique du développement humain. Ce dernier est soulevé dans la thèse à travers la mise en lumière de l’importance de la participation citoyenne, déjà active et qui compte déjà plusieurs expériences à son actif. Le besoin de l’empowerment ou du renforcement de ses capacités, par la formation et le financement, est aussi soulevé pour révéler l’importance d’une action qui est déjà en germe et qui a besoin de soutien et d’accompagnement. En somme, le développement touristique dans les espaces sahariens, comme nous l’avons étudié à travers le cas de la région du Tafilalet, devrait rendre à l’homme oasien la place qu’il se doit d’occuper comme acteur dans son propre espace, à travers une stratégie de tourisme durable où le spatial autant que l’humain, l’économique et l’environnemental sont pris en considération. De fait, dans cet espace fragile et vulnérable les considérations environnementales et humaines sont aussi importantes que les variables de rentabilité, et devraient être au centre de toute réflexion sur le développement touristique territorial. / Tafilalet is a Saharan region of Morocco. Located in the south-east, in a border area, it shows signs of a weak desert space and a marginalized one. Its geographical location, climatic features and morphological profile make it a structurally vulnerable space, that offers little chance for human and economical development. Yet it was able to shine and experienced a boom during the Middle Age. This one has seen the development of a great arid civilization whose features are still living in the oasis agro-pastoral production system. These features have led to the establishment of a delicate balance between the oasis man, its needs and demand and a fragile environment with weak development capacities. Balance since broken by modernity, rural exodus, urbanization and salaried work. Newly arrived in the oasis economical system, tourism has developed from the early twentieth century and has undergone significant changes, to become the first formal economical activity in the area. The desert, the dunes, the palmgrove are the main advantages of this product which tries, increasingly, to combine with the original landscape offer a range of a cultural one consisting of the built heritage, human and tribes wealth as well as the commercialization of the desert as playful space (sport tours : quad, mountain biking ...). Thus the product is, gradually, free of the classical desert spots (dunes and camels) and the area opened to a an integrate and diffuse tourism, exploring the hinterland, drawing multi-activity, immersion in the Saharan and nomad daily life and a cross-cultural exchange between tourists and residents. The area of ​​our study as well as the Saharan area in whole, live a touristic growth but in a kind of anarchy and spontaneity. In sum tourism can be, for several reasons, a threat factor of oasis nature, its landscape, its capacity in terms of water and soil and to the agro-pastoral production system, known to be mainly, a subsistence and traditional one. The development of tourism in Tafilalet region should happen through a strategy of sustainable development where tourism is approached by a territorial vision. The place of the local governance, the local actor are very important to us. Development must be understood in that sense in and for the territory as a space for life and action, away from sectors visions which had only prevailed useful areas and marginalized the majority of the Saharan territory. This approach should also call the specificities of this unique space both in geographical and human aspects. These ones should be in the center of its conception as well as the natural stress, the fragility and vulnerability of the environmental elements ... All of that cannot be separated from the problem of the human development. It is raised in this thesis through a highlight of the importance of citizen participation, already active and that has several experiences to its credit. The need to empower his action by training and funds may reveal the importance of an action that is already in germ and which needs to be supported and assisted. In sum, the development of tourism in the Saharan areas, as we have shown through the case of the Tafilalet region, should give the oasis-man his place as the first actor of his own development. This conception could be done through a strategy of sustainable tourism where the spatial as well as the human, the economical and the environmental elements are considered. In this fragile and vulnerable area human and environmental considerations are as important as profitability variables for any territorial tourism development strategy.

World-wide, there has been a large increase in tertiary student numbers, not entirely matched by funding increases. Consequently, instructors are faced with large, diverse classes, and find themselves struggling to provide adequate assessment and prompt feedback, two quantities critical in an effective learning environment. Personal computers and the Internet can help solve this problem. The aim of this study was to develop, implement and validate a Web-based software package that, through providing practice and assessment opportunities, improved student learning and reduced marking and related mundane aspects of instructor workload. At the start of the study, such a package already existed in prototype form: OASIS (Online Assessment System with Integrated Study). As the study progressed, this software package was first fully rewritten and then repeatedly modified. OASIS delivers individualised tasks, marks student responses, supplies prompt feedback, and logs student activity. Staff can deliver sets of practice questions and assessments to students: assessments may involve different questions for different students, not just numerically different versions of the same questions. Given my role as teacher, the traditional research ideal of observing without affecting the research environment was both impossible and unconscionable. In particular, since preliminary evidence suggested that OASIS did enhance student learning, I could not adopt a ‘two groups’ approach to the research, with one group using OASIS while the other did not. Instead, an action research methodology was seen as most appropriate for my double role of teacher and researcher. / This methodology enabled me, in the light of my findings, to continuously modify the learning environment and enhance student learning. The action research proceeded through a spiral of one-semester cycles of planning, acting, observing and reflecting. To maximize rigour, the research ran through eight cycles over four years and involved considerable triangulation. OASIS itself collected much quantitative data. Further data were collected via interview, survey, email and informal discussion from three groups: current students, postgraduates and academics. My colleagues provided alternative perceptions and interpretations, as did Physics Department academics who were using OASIS, and an external academic who interviewed academics and investigated the implementation of OASIS. Perhaps surprisingly, academics had generally adopted OASIS to promote student learning rather than to decrease their own workloads. In some cases workloads were reduced; however, where OASIS assessments augmented rather than replaced existing traditional assessments, workloads actually went up slightly. All instructors who used OASIS reported enhanced student learning and wished to continue using it. Student surveys, interviews, focus-group discussions and informal feedback showed that students found the software easy to use and considered that it helped them improve their skills and understanding. OASIS questions were preferred over textbook questions. Students commonly requested OASIS to be available in more of their areas of study. In general students wanted hints or model answers though some argued against their provision. / The majority of students were enthusiastic about the use of OASIS for practice, and activity logs revealed that they did use OASIS extensively. These logs also revealed the motivating power of assessments: typically half the online practice activity took place in the last 36 hours prior to assessments. Interviews provided further interesting insights into the ways different students approached their studies and assessments. However, students did voice concerns about the validity of OASIS assignments, noting their peers could rely on the efforts of others to score highly in these. A number of steps were carried out in an attempt to defuse these concerns, including: disabling OASIS practice during assignments, basing assignments on previously unseen questions, and providing different assignment questions to different students. While this study has achieved the goal of developing, implementing and validating OASIS, many future opportunities exist. OASIS may be used in schools as well as universities. Non-numerical questions, where answers may be somewhere between right and wrong, are possible. OASIS can also be used to deliver concept inventories to students to support research into concept acquisition and retention.

Im Rahmen einer deutsch-australischen Forschungskooperation erfolgte im Südsommer 2001/2002 eine Expedition in die Amery-Oase (70°50’S, 68°00’E), die im Einzugsgebiet des Lambert-Gletscher/Amery-Schelfeis-Systems, dem größten ostantarktischen Eis-Drainagesystem, liegt. Von deutscher Seite wurden im Zuge der Geländekampagne erstmals lakustrine Sedimentsequenzen gewonnen, um die bislang wenig erforschte spätquartäre Klima- und Umweltgeschichte dieser rund 1800 km² großen eisfreien Region zu rekonstruieren. Die drei untersuchten Glazialseen Beaver, Radok und Terrasovoje unterscheiden sich sowohl deutlich in ihrer Größe, Bathymetrie und den hydrologischen Merkmalen sowie in ihren Sedimentabfolgen. <br><br> Einen Schwerpunkte dieser Doktorarbeit bildet die Rekonstruktion der Sedimentationsprozesse und des Ablagerungsmilieus sowie Untersuchungen zur Herkunft des detritischen Sedimentmaterials in den Seebecken. Der methodische Ansatz verfolgt die Charakterisierung der klastischen Sedimentfazies an Hand lithologisch-granulometrischer Merkmale sowie mineralogisch-geochemischer Analysen der Sedimentherkunft. Ein weiterer Schwerpunkt ist die Rekonstruktion der holozänen biogen gesteuerten Ablagerungsbedingungen im Terrasovoje-See, die Rückschlüsse auf den kurzfristigen postglazialen Klima- und Umweltwandel in der Amery-Oase gestattet. Dabei wurden mikrofazielle Untersuchungsmethoden und hochauflösende Elementscannermessungen angewandt. <br><br> Die klastische Sedimentherkunft in den drei Seen unterscheidet sich räumlich deutlich voneinander und spiegelt den komplexen geologischen Aufbau der Amery-Oase wider. Als Sedimentquellen konnten präkambrische Metamorphite, permotriassische Sedimentgesteine und tertiäre Lockersedimente identifiziert werden. Die Varibilität der Herkunftssignale ist zeitlich weniger deutlich als räumlich ausgeprägt und deutet auf relativ konstante Liefergebiete in den einzelnen Seen hin. <br><br> Das glaziolakustrine Ablagerungsmilieu der drei untersuchten Seen zeigt klare räumliche und zeitliche Unterschiede. In allen drei Seen setzen sich die älteren Sedimente aus grobkörnigem, häufig diamiktischem Material zusammen, während die jüngeren Sedimente aus feinkörnigen Laminiten bestehen. Die lithofazielle Zweiteilung in den Sedimentabfolgen deutet auf einen Rückzug der Gletscher und/oder einen Anstieg der Wassertiefen im Übergang von den grobkörnigen zu den feinkörnigen Ablagerungseinheiten hin. Die oberen feinkörnigen Kernabschnitte spiegeln in allen drei Seen die postglaziale lakustrine Sedimentation wider. Im Beaver-See wird die postglaziale Fazies durch laminierte klastische Stillwassersedimente repräsentiert, im Radok-See durch Turbiditsequenzen und im Terrasovoje-See durch Algenlaminite. <br><br> Abgesehen vom Terrasovoje-See ist die zeitliche Einordnung der Fazieswechsel auf Grund mangelnder Altersinformationen schwer erfassbar. Im Terrasovoje-See setzte die postglaziale Sedimentation um rund 12,4 cal. ka ein. Somit weisen die darunterliegenden glazigenen Klastika mindestens ein spätpleistozänes Alter auf. Die sedimentologischen Eigenschaften, Änderungen der Sedimentationsraten und organogene Zusammensetzung der postglazialen Biogenlaminite des Terrasovoje-Sees deuten auf Variationen der paläolimnologischen Bedingungen hinsichtlich Eisbedeckung, biologischer Produktivität, Wasserstand, Redoxbedingungen und Salinität hin, die mit regionalen holozänen Klimaänderungen in Verbindung gebracht werden können. Weitere Anhaltspunkte ergeben sich aus der Zusammensetzung und den Mächtigkeitsvariationen der Laminae, die generell aus Wechsellagerungen von Cyanobakterienmatten mit feinklastischen Lagen bestehen. Lagenzählungen der Laminae belegen Änderungen des Ablagerungsmilieus auf subdekadischen Zeitskalen, wobei zeitweilige jährliche Signale nicht ausgeschlossen werden können. Unter Berücksichtigung aller faziellen Indikatoren lässt sich aus der Sedimentabfolge des Terrasovoje-Sees ein frühholozänes Klimaoptimum zwischen 9 und 7 cal. ka sowie weitere Wärmephasen zwischen 3,2 und 2,3 cal. ka sowie 1,5 und 1,0 cal. ka ableiten. <br><br> Im Vergleich mit Eiskernarchiven und anderen Seesedimentabfolgen aus ostantarktischen Oasen zeigt sich, dass das Auftreten postglazialer Warmphasen nicht allenorts einem allgemein gültigen räumlich-zeitlichen Muster folgt. Die Ursachen hierfür liegen vermutlich in den lokalen geographischen Gegebenheiten. Es lässt sich daraus schliessen, dass die bisher vorliegenden Klimarekonstruktionen eher das Lokalklima an einem Untersuchungsstandort als das Großklima der Ostantarktis reflektieren. Daraus ergibt sich die Notwendigkeit weiterer Untersuchungen von antarktischen Klimaarchiven und Untersuchungsstandorten, um örtliche von überregionalen Klimasignalen besser unterscheiden zu können. / In the scope of a German-Australian research cooperation field work was conducted in the Amery Oasis (70°50’S, 68°00’E), situated in the Lambert Glacier/Amery Ice Shelf region, the largest East Antarctic ice drainage system. The German part comprised the retrieval of lacustrine sediment cores for the reconstruction of the late Quaternary development of the palaeoenvironment in the 1800 km² large ice-free region. The three studied glacial lakes Beaver, Radok, and Terrasovoje reveal marked differences in size, hydrology and their sedimentary inventory. The goals of this thesis were to infer the onset of depostion in the lacustrine basins and to characterize changes in the depositional environment in the course of glacial retreat and the postglacial climate development. The methodic approach followed the recognition of sedimentary facies variability and sediment sources by means of facies analysis and mineralogical-geochemical provenance analysis. Another aspect was the high-resolution reconstruction of postglacial biogenic sedimentary modes in Lake Terrasovoje that provide insights into the short-term Holocene palaeo-climatic and palaeoenvironmental development. <br><br> The origin of siliciclastics shows marked spatial differences between the lakes, reflecting the complex geological setting of the Amery Oasis. The main detrital sources comprise crystalline rocks of the East Antarctic craton, Permotriassic and Tertiary sedimentary rocks. The temporal variability of sediment provenance is less developed than the spatial pattern, pointing to relatively constant sediment sources through time in the respective lakes. <br><br> The glaciolacustrine depositional environment of the three lakes shows clear spatial and temporal contrasts. In all lakes, the older sediments are composed of coarse, partly diamictic lithologies, while the younger materials consist of fine-grained laminites. The twofold lithofacial pattern is related to regional glacial retreat at the boundary between both sedimentary units that reduced direct glacigenic sediment input. In the epishelf Lake Beaver, in addition, the effect of postglacial sea-level rise led also to the rise of lake level and shifted the study site towards a more distal position from the shore, away from the influence of coarse clastic sediment input. The upper sedimentary units of the three lakes are dominated by fine-grained sediments, which only occasionally include ice-rafted dropstones. The postglacial sediments comprise clastic stillwater laminites at Lake Beaver, finely laminated turbidites in Lake Radok, and algal laminites in Lake Terrasovoje. <br><br> Apart from Lake Terrasovoje the timing of the lithological change is hard to determine, because of missing age constraints. At Lake Terrasovoje, the postglacial sequence started at approximately 12.4 cal. ka BP, suggesting an late Pleistocene age for the underlying glacial sediments. Sedimentological features, changes in sedimentation rates, and the compositional variability of the organic-rich postglacial laminites in Lake Terrasovoje point to variations in the palaeolimnic environment in terms of ice cover, biological productivity, lake level, redox conditions, and salinity that can be related to the regional Holocene climate history. Further evidence arises from the structure, composition, and thickness variations of the laminae, which basically consist of alternations of algal mats (cyanobacteria) and fine-clastic layers. The counting of laminae couplets reveal changes in the depositional enviroment at sub-decadal time scales that partly might include annual layering. Under the consideration of all sedimentological facies indicators, the postglacial laminite sequence of Lake Terrasovoje documents an early Holocene climate optimum between 9 and 7 cal. ka as well as two warm spells between 3.2 and 2.3 cal. ka and 1.5 and 1.0 cal. ka, respectively. <br><br> In comparison with ice-core records and lake records from other East Antarctic ice-free regions, it becomes evident that the appearence of warm episodes does not follow a consistent spatial-temporal pattern. Common trends comprise the existence of an early Holocene climate optimum, as seen in the ice-core records and in the Amery Oasis, and several warm episodes in the middle to late Holocene that are often time-transgressive. The cause of this inconsistent pattern probably can be explained by local boundary conditions that affect the study sites, such as topography, maritime influences and the distance to glacial ice. Therefore, many climate reconstructions basically document local climate rather than overregional Antarctic climate. In conclusion, there is need for ongoing palaeoclimatic studies in East Antarctica and the establishment of a dense network of study sites to distinguish and validate local from overregional palaeoclimatic fingerprints.

Etudier la ville médiévale de Sijilmassa (Maroc) par le biais des données archéologiques, et non plus à partir des seules sources textuelles, constitue un changement de paradigme qui n’a été, à ce jour, que peu approfondi. Percevoir cette cité saharienne et son oasis par le biais de données intrinsèques, et non plus uniquement par la perception qu’en avaient les voyageurs, les géographes et les chroniqueurs venus de l’extérieur, permet pourtant un renouvellement important des questionnements et des connaissances au sujet de ce carrefour caravanier du sud marocain. Cette thèse de doctorat se propose, au moyen de l’exploitation des archives de fouilles inédites du Moroccan-American Project at Sijilmasa (MAPS) et des données tirées de nouvelles prospections archéologiques menées au Tafilalt, la région de Sijilmassa, de procéder à une nouvelle lecture de l’histoire de la ville saharienne en s’appuyant sur deux axes d’étude principaux : l’histoire environnementale de la cité et l’histoire urbaine du site archéologique. En procédant par éclairages successifs, du fait du caractère disparate du corpus documentaire, cette recherche s’inscrit pleinement dans l’héritage de l’équipe maroco-américaine dont elle est totalement tributaire, tout en dépassant les conclusions de ce précédent programme : elle met en évidence de grandes dynamiques, économiques, écologiques, démographiques et sociales, permettant d’expliquer la place prépondérante qu’a acquis, durant toute l’époque médiévale, cette cité dans l’histoire du commerce africain et de mieux cerner ses processus d’émergence, de déclin et de transformation. / Studying medieval Sijilmasa (Morocco) through archaeological data, and not just from textual sources, is a paradigm shift that has not, to date, been done in sufficient depth. Perceiving this Saharan oasis city through intrinsic data, rather than only through the perception of outside travelers, geographers and chroniclers, allows a significant reopening of questioning about this caravan crossroads in southern Morocco. This thesis proposes, through the exploitation of unpublished excavation archives of the Moroccan-American Project at Sijilmasa (MAPS) and data from new archaeological surveys conducted in the Tafilalt region of Sijilmasa, to reread the history of the Saharan city relying on two main research areas: environmental history of the city and urban history of the archaeological site. Proceeding by successive steps and considering the disparate nature of the documentary corpus, this research is fully the beneficiary of the Moroccan-American team upon which it is totally dependent, all while being able to add to the conclusions of the previous program. It reveals major economic, ecological, demographic and social dynamics to explain the city’s emergence, decline, and transformation, as well as the prominence that it acquired, throughout medieval times, in the history of African trade.