As sociedades e instituições arqueológicas, como as demais organizações científicas, são espaços fundamentais no fomento e na manutenção da rede de intelectuais de sua área de pesquisa. Podem, através da veiculação de suas publicações, apontadas na seção editorial de boletins dessas organizações, reafirmar as tradições arqueológicas ou oferecer perspectivas inovadoras. Analisamos trinta e quatro editoriais das publicações The South African Archaeological Bulletin, Nyame Akuma e Nsi, intentando compreender a formação das múltiplas imagens dos arqueólogos africanos e africanistas na era pós-colonial, entre 1987 e 1993, que, a nosso ver, dar-se-ia diante daquilo que essas sociedades através de seus boletins consolidam. Segundo a ótica de seus editores, os boletins do corpus de nossa pesquisa eram meios de comunicação rápidos e eficientes para cumprir funções de possibilitar que os arqueólogos interagissem, que se informassem sobre o andamento das pesquisas de campo e que fossem comunicados quanto à realização de congressos entre seus pares. Nosso recorte temporal define-se pela circulação concomitante dos três boletins, exceto quanto ao Nsi, que foi, um ano antes, em 1992, assimilado ao Nyame Akuma. Esse recorte temporal, a propósito, foi marcado pelas correntes teóricas da Nova Arqueologia, do Pós-Processualismo, dos estudos pós-coloniais e pela divulgação da pesquisa arqueológica na África e sobre a África em face dessas abordagens. Apontamos a título de conclusão da análise que os boletins, sob o pretexto de favorecer os arqueólogos e a produção científica em arqueologia na África durante esse período, veiculavam, na verdade, as imagens ideais ou mesmo as rechaçadas dos arqueólogos interessados na África. Essas imagens eram construídas nos textos dos editores na prática discursiva que formulavam com temas ligados ao ofício do arqueólogo. / The archaeological societies and institutions, like others scientific organizations, they are fundamental spaces in the encouragement and in the support an intellectual\'s network of the research´s area. They can, through the distribution of its publications, like the newsletters, in the editorial section, to reaffirm traditions or offer innovative perspectives. We analyzed thirty and four editorial texts in The South African Archaeological Bulletin, Nyame Akuma and Nsi, intending to understand structure multiple images\' of Africans and Africanists Archaeologists in the post-colonial era, between 1987 and 1993, that, in our opinion, would it is happen before of that societies through its newsletters consolidate. According to the viewpoint their editors, the newsletters of our documental corpus were agile and efficient to fulfill the functions to make possible archaeologists interact, they knew about the fieldwork\'s progress, they were informed about the realization of Congress. Our temporal period is defined by the concomitant movement of the bulletins, with the exception of the year 1993, when Nsi was assimilated to Nyame Akuma. It\'s a period was marked by New Archaeology´s theoretical currents, Post-processualism, postcolonial studies and dissemination of archaeological research in the Africa and about the Africa in face of these approaches. We point as conclusion of the analysis like the bulletins, under the pretext of promoting the archaeologists and the scientific archeology in the Africa, during in this period, they conveyed, in fact, the ideal or rejected images of the interested archaeologists in Africa. These images were constructed in the editor\'s texts in discursive practice that they formulated. They were recurring statements of the contingent themes at the archaeologist´s work.

RESUME Les données phytogéographiques reflètent la variabilité spatiale de la diversité des espèces et constituent donc un outil important dans le développement des politiques de conservation. Afin de stimuler et de valoriser le concept des systèmes phytogéographiques, cette étude dont le thème est «Analyse des structures spatiales des données de distribution phytogéographique des Acanthaceae en Afrique centrale» s’est donnée pour but (1) d’analyser la distribution spatiale de la famille des Acanthaceae en Afrique Centrale (R.D. Congo, Rwanda, Burundi) ; (2) de comparer cette distribution avec les théories phytogéographiques de Robyns (1948), White (1979, 1986) et Ndjele (1988); (3) d’utiliser les modèles de distribution spatiale comme support (outil) pour évaluer l'impact humain sur le paysage et la diversité; (4) d’identifier les espèces indicatrices potentielles des territoires phytogéographiques; (5) de mettre en évidence le phénomène de vicariance; et (6) de quantifier l’impact de la fragmentation du paysage forestier en Afrique centrale. Dans cette étude, deux niveaux de résolution spatiale ont été considérés: les systèmes phytogéographiques et les systèmes de maillage. Un système d’information géographique a été utilisé pour réaliser des cartes de distribution spatiale de chaque espèce. Le choix des Acanthaceae de l’herbier du Jardin Botanique National de Belgique (BR), a été dicté par le faite qu’elle a subit une révision systématique et par le nombre important de ses échantillons. L’aspect floristique a révélé 9181 échantillons, récoltés de 1888 à 2001 par environ 427 collecteurs en R.D. Congo, au Rwanda et au Burundi représentant 48 genres, 310 espèces et 6362 localités. La carte de distribution spatiale de l’ensemble des échantillons a mis en évidence les niveaux de prospection. Certains territoires phytogéographiques ont été plus explorés que d’autres. Les entités phytogéographiques les plus explorées et donc les plus diversifiées sont le centre régional d’endémisme Afromontagnard, incluant la Mosaïque régional du lac Victoria, et le centre régional d’endémisme Zambézien. Les cartes de distribution de chaque espèce mettent en évidence les patrons de distribution spatiale. Certaines espèces ont une large distribution alors que d’autres sont inféodées à certaines zones spécifiques. Ces dernières, qualifiées « d’espèces uniques » ou « espèces caractéristiques » peuvent être utilisées comme des bio-indicateurs pour stimuler et valoriser le concept de systèmes phytogéographiques dans la politique de la conservation. En utilisant uniquement la famille des Acanthaceae, il a été montré que l’impact de la fragmentation du paysage forestier est très important. Les espèces inféodées à une région phytogéographique sont des espèces vulnérables. Elles peuvent disparaître si leur biotope est détruit. La distribution potentielle, basées sur les localités de récolte et les variables environnementales, ont été réalisées afin de mieux déterminer les niches écologiques des espèces et les cas de vicariance. Deux types de vicariance ont été mis en évidence à travers les systèmes phytogéographiques de Robyns (1948) et de White (1979, 1986), au niveau générique et spécifique: la vicariance écologique et la vicariance géographique. La vicariance écologique s’applique aux espèces ou sous-espèces récoltées dans les mêmes territoires phytogéographiques tandis que la vicariance géographique concerne les espèces ou sous-espèces récoltées dans des territoires phytogéographiques séparés. L’analyse des cas de vicariance a mis en relief les zones de spéciation. L'analyse de classification hiérarchique a montré que les Acanthaceae suivent mieux le système phytogéographique de White (1979, 1986) que ceux proposés par Robyns (1948) et Ndjele (1988). Pour mieux valoriser cette approche, cette méthodologie doit être appliquée à d’autres familles largement récoltée en R.D. Congo, au Rwanda et au Burundi comme la famille des Rubiaceae, des Mimosoideae, afin de (1) synchroniser toutes les bases de données pour mieux mettre en évidence le degré d’exploration, les espèces à amplitude écologique restreinte (espèces uniques) et (2) de permettre d’identifier des zones prioritaires pour la conservation. ABSTRACT Phytogeographic data reflect the spatial variability of plant diversity and constitute consequently a potential tool for conservation policy development. In order to stimulate and valorise the concept of phytogeographic systems, this dissertation entitled “Analysis of the spatial pattern of phytogeographic data of Acanthaceae in Central Africa” aims (1) to analyse the spatial distribution of the Acanthaceae family in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi); (2) to compare this distribution with the known phytogeographic theories of Robyns (1948), White (1979, 1986) and Ndjele (1988); (3) to use the spatial distribution models as a tool for evaluating the human impact on landscapes and diversity; (4) to identify potential indicator species of the phytogeographic territories; (5) to evidence the phenomenon of vicariance; and (6) to quantify the impact of the fragmentation of forested landscapes in central Africa. In this study, two levels of spatial resolution have been considered: the phytogeographic systems themselves and a system of grid cells. A geographic information system has been used to draw maps of the spatial distribution of every species. The choice to analyse the Acanthaceae family of the herbarium of the National Botanical Garden of Belgium (BR) has been justified by the systematic revision of this collection and by its huge number of samples. The data set contained 9181 samples, collected between 1888 and 2001 by about 427 collectors in the Democratic Republic of the Congo, Rwanda and Burundi ; the samples represented 48 genera, 310 species and 6362 geographic positions. The maps showing the spatial distribution of all samples pooled evidenced the different levels of exploration of the study area. Certain phytogeographic territories have been explored more intensely than others. The mostly explored zones, consequently also denoted as the most diverse ones, were the Afromontane regional centre of endemism, including the regional mosaic of Lake Victoria, and the Zambezian regional center of endemism. Species distribution maps evidenced the spatial patterns of species presence. Certain species showed an overall distribution while others were clearly bound to particular territories. The latter species, denoted as “unique species” or “characteristic species” could be used as bio-indicators to stimulate and valorise the concept of the phytogeographic systems in the framework of conservation policy development. By means of the Acanthaceae family, it has been shown that the impact of forest fragmentation will be considerable; species bound to a specific phytogeographic zone are assumed vulnerable; they will disappear when their biotopes are destroyed. The potential distribution of the species, based on the geographic position of the samples and on environmental data, have been generated in order to describe more precisely the ecological niches of the species involved and to detect cases of vicariance. Two types of vicariance have been found using the phytogeographic territories of Robyns (1948) and White (1979, 1986) at the genus and the species levels: ecological vicariance and geographic vicariance; the former type involves species or subspecies observed in the same phytogeographic region while the latter type involves species and subspecies not found in the same territory. This analysis enabled us to identify zones of speciation. A cluster analyses showed that the spatial distribution of the Acanthaceae data corresponded more closely to the phytogeographic system of White (1979, 1986), than to those proposed by Robyns (1948) or Ndjele (1988). In order to valorise our approach, the current methodology should also be applied to other families widely collected in the Democratic Republic of the Congo, Rwanda and Burundi, such as the Rubiaceae or Mimosoideae families, this (1) to synchronise all data bases for a more profound understanding of the degree of exploration and of the existence of species with a limited ecological amplitude (unique species), and (2) to enable the identification of zones that should be prioritised for conservation.

L’Afrique centrale atlantique (ACA) englobe l’ensemble du domaine bas-guinéen, les îles du Golfe de Guinée et une partie de l’archipel afromontagnard. Plusieurs centres d’endémisme ont été identifiés en son sein et sont généralement considérés comme liés à la présence de refuges forestiers durant les périodes glaciaires. Cependant, l’origine de cet endémisme, sa localisation et les méthodes permettant d’identifier ces centres restent controversées. La localisation de ces zones d’endémisme et des plantes rares qu’elles abritent, est pourtant un prérequis indispensable pour la mise en place de politiques cohérentes de conservation et demeure une priorité pour les organisations privées, institutionnelles ou gouvernementales actives dans la gestion et le maintien durable de la biodiversité. Cette étude phytogéographique porte sur la famille des Orchidaceae et est basée sur l’analyse de la distribution des taxons endémiques de l’ACA. Elle s’appuie sur un jeu de données original résultant d’un effort d’échantillonnage important au Cameroun et d’un travail d’identification et de localisation de spécimens dans les principaux herbaria européens abritant des collections d’ACA. Durant cette étude, (i) nous avons tout d’abord identifié ces taxons endémiques et documenté leur distribution au travers de plusieurs contributions taxonomiques et floristiques, (ii) nous nous sommes ensuite intéressé aux nouvelles méthodes permettant d’analyser ces données d’herbier de plantes rares et donc pauvrement documentées, testant aussi l’intérêt des Orchidaceae comme marqueurs chorologiques, et finalement, appliquant ces méthodes à notre jeu de données, (iii) nous avons délimité des centres d’endémisme et identifié les territoires phytogéographiques des Orchidaceae en ACA. (i) Une révision taxonomique des genres Chamaeangis Schltr. et Stolzia Schltr. a été réalisée respectivement. Sept nouveaux taxons ont été décrits: Angraecum atlanticum Stévart & Droissart, Chamaeangis spiralis Stévart & Droissart, Chamaeangis lecomtei (Finet) Schltr. var. tenuicalcar Stévart & Droissart, Polystachya engogensis Stévart & Droissart, Polystachya reticulata Stévart & Droissart, Stolzia repens (Rolfe) Summerh var. cleistogama Stévart, Droissart & Simo et Stolzia grandiflora P.J.Cribb subsp. lejolyana Stévart, Droissart & Simo. Plusieurs notes taxonomiques, phytogéographiques et écologiques supplémentaires ont également été redigées. Au total, nous avons identifié 203 taxons d’Orchidaceae endémiques d’ACA parmi lesquels 193 sont pris en compte pour l’étude des patrons d’endémisme. (ii) Au Cameroun, les patrons de distribution des Orchidaceae et des Rubiaceae endémiques d’ACA ont été étudiés conjointement. Des méthodes de rééchantillonnage des données (raréfaction) ont été appliquées pour calculer des indices de diversité et de similarité. Elles ont permis de corriger les biais liés à la variation de l’effort d’échantillonnage. Un gradient de continentalité a été observé, les parties côtières étant les plus riches en taxons endémiques d’ACA. Contrairement à la région du Mont Cameroun et aux massifs de Kupe/Bakossi qui ont connu une attention particulière des politiques et des scientifiques, la partie côtière du sud Cameroun, presque aussi riche, reste mal inventoriée pour plusieurs familles végétales. Cette analyse à l’échelle du Cameroun a également permis de comparer les patrons d’endémisme des Orchidaceae et des Rubiaceae. Les différences observées seraient principalement dues à la présence d’Orchidaceae terrestres dans les végétations basses et les prairies montagnardes de la dorsale camerounaise alors que les Rubiaceae sont généralement peu représentées dans ces habitats. Au sein des habitats forestiers, la concordance entre les patrons d’endémisme des Orchidaceae et des Rubiaceae remet en question l’utilisation des capacités de dispersion des espèces comme critère pour choisir les familles permettant l’identification des refuges forestiers et semble ainsi confirmer la pertinence de l’utilisation des Orchidaceae comme marqueur chorologique. La distribution potentielle a été utilisée pour étudier en détail l’écologie, la distribution et le statut de conservation de Diceratostele gabonensis Summerh., une Orchidaceae endémique de la région guinéo-congolaise uniquement connue d’un faible nombre d’échantillons. Cette méthodologie semble appropriée pour compléter nos connaissances sur la distribution des espèces rares et guider les futurs inventaires en Afrique tropicale. (iii) En ACA, les Orchidaceae permettent d’identifier plusieurs centres d’endémisme qui coïncident généralement avec ceux identifiés précédemment pour d’autres familles végétales. Ces constats supportent aussi l’utilisation des Orchidaceae comme marqueur chorologique. La délimitation des aires d’endémisme des Orchidaceae a ainsi permis de proposer une nouvelle carte phytogéographique de l’ACA. Les éléments phytogéographiques propres à chacune des dix phytochories décrites ont été identifiés et leurs affinités floristiques discutées. Les résultats phytogéographiques obtenus (a) soutiennent l’existence d’une barrière phytogéographique matérialisée par la rivière Sanaga entre les deux principaux centres et aires d’endémisme de l’ACA, (b) étendent l’archipel afromontagnard situé principalement au Cameroun au plateau de Jos (Nigeria) et (c) montrent l’importance de la chaîne montagneuse morcelée Ngovayang-Mayombe pour la distribution de l’endémisme en ACA. Cette chaîne de montagne, qui s’étend le long des côtes de l’océan du sud Cameroun au Congo-Brazzaville et qui correspond à plusieurs refuges forestiers identifiés par de nombreux auteurs, est ici considérée comme une seule aire d’endémisme morcelée./ Atlantic central Africa (ACA) covers the Lower Guinean Domain, the four islands of the Gulf of Guinea and a part of the afromontane archipelago. Different centres of endemism have been identified into this area and are usually considered as related to glacial forest refuges. However, the origin of this endemism, the localization of the centres and the methods employed to identify these centres are subject to debate. Yet, the localization of these centres of endemism and the identification of the rare plants they harbor is an essential prerequisite to setting up rational conservation policies, and remains a priority for private, institutional and governmental organizations which are dealing with the sustainable management of biodiversity. This phytogeographical study focuses on Orchidaceae and analyses the distribution of the taxa endemic to ACA. We use an original dataset resulting from an important sampling efforts and the identification of specimens coming from all the principal herbaria where collections from ACA are housed. During this study, (i) we first identified the taxa endemic to ACA and documented their distribution through several taxonomic and floristic contributions, (ii) we used and developed new methods allowing to correct for sampling bias associated with the use of rare and poorly documented taxa, testing at the same time the use of Orchidaceae as chorological markers, and finally, applying these methods to our dataset, (iii) we delimited the centres of endemism and identified the phytogeographical territories of Orchidaceae in ACA. (i) A taxonomic revision of Chamaeangis Schltr. and Stolzia Schltr. respectively was carried out. Seven new taxa were described: Angraecum atlanticum Stévart & Droissart, Chamaeangis spiralis Stévart & Droissart, Chamaeangis lecomtei (Finet) Schltr. var. tenuicalcar Stévart & Droissart, Polystachya engogensis Stévart & Droissart, Polystachya reticulata Stévart & Droissart, Stolzia repens (Rolfe) Summerh var. cleistogama Stévart, Droissart & Simo and Stolzia grandiflora P.J.Cribb subsp. lejolyana Stévart, Droissart & Simo. Several additional taxonomic, phytogeographical and ecological notes were also published. We finally identified 203 Orchidaceae taxa endemic to ACA, among which 193 were used to study the patterns of endemism. (ii) In Cameroon, the distribution patterns of both Orchidaceae and Rubiaceae endemic to ACA were studied. Subsampling methods (rarefaction) were applied to calculate diversity and similarity indices and to correct potential bias associated with heterogeneous sampling intensity. A gradient of continentality was confirmed in Cameroon, the coastal part being the richest in taxa endemic to ACA. The Cameroon Mountain and the Kupe/Bakossi mountain massifs have received a great consideration of politics and scientists. On the contrary, the Southern coastal part of Cameroon, though almost as rich as the Northern part, remains poorly known for several plant families. This analysis also allowed us to compare patterns of endemism of Orchidaceae and Rubiaceae. The differences observed could be mainly due to the terrestrial habit of some Orchidaceae, which are only found in the grasslands of the highest part of the Cameroonian volcanic line where endemic Rubiaceae are rare. Within forest habitats, the concordance between the patterns of endemism of Orchidaceae and Rubiaceae question the widespread use of dispersal ability as a selection criterion for the families used to identify forest refuges. This also confirms the relevance of Orchidaceae as chorological marker. Species distribution modelling was used of an in depth study of the ecology, the distribution and the conservation status of Diceratostele gabonensis Summerh., an Orchidaceae endemic to the Guineo-Congolian regional centre of endemism which is only known from very few collections. This method is proved to be appropriate to complete our knowledge on the distribution of rare plant species and to guide the future inventories in tropical Africa. (iii) In ACA, an analysis of the distribution of endemic Orchidaceae confirmed the presence and location of several centres of endemism previously identified on the basis of other plant families. This result again supports the use of Orchidaceae as a chorological marker. The chorological study of the endemic Orchidaceae allowed us to propose a new phytogeographical map for ACA. Phytogeographical elements for each of the ten phytochoria described were identified and their floristic affinities were also discussed. Our results (a) support the existence of a phytogeographical barrier, materialized by the Sanaga River, between the two main centres and area of endemism of the ACA, (b) extend the limits of the afromontane archipelago to the Jos Plateau in Nigeria and (c) show the importance of the Ngovayang-Mayombe line to explain the distribution of endemism in ACA. This mountainous line, stretching along the ocean coast from Southern Cameroon to Congo-Brazzaville, corresponds to several forest refuges identified by many authors, and is here considered as an unique but discontinuous area of endemism.

Over 50 years ago, Marshall McLuhan (2003), a specialist in communication issues, said that the world is becoming smaller and smaller every starting day, a result of the emergence of modern communication around the world. This situation has given birth to the conept `new technology´. This article will break down this new concept by looking at it through the lens of oral literature, which is used in Swahili communities. However, oral Swahili literature uses Kiswahili language, which is the languagge of communication at different levels throughout East and central Africa. The article will examine the ideals and opinions connected to oral literature described in the existing academic literature, and as one of the genres of narrative literature. It will look at the way in which the concept of new technology is explained by specialists, and in which ways this connects to oral literature. Advantages and effects which came about in the society after the coming of this notion will be discussed. The article ends with a conclusion and possible recommendations.

Hovedopgave. / Format: PDF. Bibl.

As sociedades e instituições arqueológicas, como as demais organizações científicas, são espaços fundamentais no fomento e na manutenção da rede de intelectuais de sua área de pesquisa. Podem, através da veiculação de suas publicações, apontadas na seção editorial de boletins dessas organizações, reafirmar as tradições arqueológicas ou oferecer perspectivas inovadoras. Analisamos trinta e quatro editoriais das publicações The South African Archaeological Bulletin, Nyame Akuma e Nsi, intentando compreender a formação das múltiplas imagens dos arqueólogos africanos e africanistas na era pós-colonial, entre 1987 e 1993, que, a nosso ver, dar-se-ia diante daquilo que essas sociedades através de seus boletins consolidam. Segundo a ótica de seus editores, os boletins do corpus de nossa pesquisa eram meios de comunicação rápidos e eficientes para cumprir funções de possibilitar que os arqueólogos interagissem, que se informassem sobre o andamento das pesquisas de campo e que fossem comunicados quanto à realização de congressos entre seus pares. Nosso recorte temporal define-se pela circulação concomitante dos três boletins, exceto quanto ao Nsi, que foi, um ano antes, em 1992, assimilado ao Nyame Akuma. Esse recorte temporal, a propósito, foi marcado pelas correntes teóricas da Nova Arqueologia, do Pós-Processualismo, dos estudos pós-coloniais e pela divulgação da pesquisa arqueológica na África e sobre a África em face dessas abordagens. Apontamos a título de conclusão da análise que os boletins, sob o pretexto de favorecer os arqueólogos e a produção científica em arqueologia na África durante esse período, veiculavam, na verdade, as imagens ideais ou mesmo as rechaçadas dos arqueólogos interessados na África. Essas imagens eram construídas nos textos dos editores na prática discursiva que formulavam com temas ligados ao ofício do arqueólogo. / The archaeological societies and institutions, like others scientific organizations, they are fundamental spaces in the encouragement and in the support an intellectual\'s network of the research´s area. They can, through the distribution of its publications, like the newsletters, in the editorial section, to reaffirm traditions or offer innovative perspectives. We analyzed thirty and four editorial texts in The South African Archaeological Bulletin, Nyame Akuma and Nsi, intending to understand structure multiple images\' of Africans and Africanists Archaeologists in the post-colonial era, between 1987 and 1993, that, in our opinion, would it is happen before of that societies through its newsletters consolidate. According to the viewpoint their editors, the newsletters of our documental corpus were agile and efficient to fulfill the functions to make possible archaeologists interact, they knew about the fieldwork\'s progress, they were informed about the realization of Congress. Our temporal period is defined by the concomitant movement of the bulletins, with the exception of the year 1993, when Nsi was assimilated to Nyame Akuma. It\'s a period was marked by New Archaeology´s theoretical currents, Post-processualism, postcolonial studies and dissemination of archaeological research in the Africa and about the Africa in face of these approaches. We point as conclusion of the analysis like the bulletins, under the pretext of promoting the archaeologists and the scientific archeology in the Africa, during in this period, they conveyed, in fact, the ideal or rejected images of the interested archaeologists in Africa. These images were constructed in the editor\'s texts in discursive practice that they formulated. They were recurring statements of the contingent themes at the archaeologist´s work.

Ao longo da segunda metade do século XIX, a região da África Centro-Ocidental foi palco do processo de intensificação de expedições europeias rumo ao interior do continente que conjugavam interesses econômicos, políticos e científicos. Esta pesquisa busca analisar o papel de relevo ocupado pela cultura material na agenda científica da expedição portuguesa à Lunda chefiada pelo militar português Henrique de Carvalho entre 1884 e 1888. Pretendemos também avaliar as potencialidades que o estudo sobre os objetos apresentam enquanto fontes para a compreensão mais ampla acerca das agências históricas africanas. Para tanto, selecionamos as obras Descripção da Viagem à Mussumba do Muatiânvua (1890-1894) e Ethnographia e História Tradicional dos Povos da Lunda (1890) e, de maneira complementar, o Album da Expedição ao Muatianvua (1887) e o catálogo Collecção Henrique de Carvalho (Expedição à Lunda), editado pela Sociedade de Geografia de Lisboa (1896). Assim, pela ótica da história social, pretendemos investigar como as exigências e predileções centro-africanas por determinados artigos moldaram as relações comerciais travadas nesse período, abordando os processos de incorporação e ressignificação de objetos particularmente, bens de prestígio e insígnias de poder - interpretados como expressões de identidades, códigos sociais e hierarquias políticas no âmbito dessas sociedades e de suas relações com os europeus. / During the second half of the nineteenth century, West-Central Africa was the stage of an intensification of European expeditions that channeled economic, political and scientific interests towards the continents interior. The following study intends to analyze the important role occupied by material culture in the scientific agenda of the portuguese expedition to the Lunda headed by military leader Henrique de Carvalho between 1884 and 1888. We also intend to evaluate the potential that the study of such objects provide like sources for a broader understanding about African agencies historical. For this purpose, we selected the works Descripção da Viagem à Mussumba do Muatiânvua (1890-1894) and Ethnographia e História Tradicional dos Povos da Lunda (1890) and in a complementary way, the Album da Expedição ao Muatianvua (1887) and Collecção Henrique de Carvalho (Expedição à Lunda), published by the Geographical Society of Lisbon (1896). Thus, from the perspective of social history, we intend to investigate how the requirements and predilections manifested in Central-African societies for certain items shaped the commercial relationships established during this period. We also address the process of the incorporation and resignification of objects - particularly prestige goods and insignia of power and how material culture can be interpreted as identity expressions, social codes and political hierarchies within those societies and their relations with the Europeans.

[pt] Esta dissertação aborda o impacto do fluxo de refugiados de guerra na segurança dos Estados anfitriões. Tal impacto foi investigado por meio de revisão bibliográfica das principais contribuições teóricas sobre a questão, e do estudo de caso da região dos Grandes Lagos, localizada na África Central. Tomando como objeto referencial de segurança os governos de tais Estados, identificou-se que tais fluxos podem representar uma ameaça econômica, política e/ou cultural, o que irá variar de acordo com o contexto específico de cada Estado. Verificou-se ainda que as questões relativas aos refugiados geram uma interdependência entre os Estados da região estudada no que se refere às suas considerações de segurança, identificando-se portanto uma dinâmica regionalista. / [en] This dissertation concerns the impact of the refugees flows on the security of the host State. Such impact was investigated through bibliographic research and the study of case of the Big Lake region, located in Central Africa. Taking as referencial the security of the governements of this States, the analysis identified that such fluxes could configures an economic, political and/or cultural threat, depending of the specific context of each State. It was also identified that the issues related with refugees generate an interdependence between the States of the region in their concerns about security, showing an regionalist dynamics.

Depuis 1996, conflits armés, grand banditisme (coupeurs de route) et razzias ont forcé des centaines de milliers de Centrafricains à migrer, à l’intérieur de leur pays (déplacés internes) ou vers l'étranger proche (réfugiés au Cameroun et au Tchad). Au travers divers courants de la géographie (politique, du développement, des mobilités), ce travail montre que les migrations forcées se construisent au croisement entre les pratiques des migrants et les choix politiques des structures d'encadrement (États, groupes armés, organisations d'aide humanitaire). Il se fonde sur une approche transversale de la migration forcée (du lieu d'origine au retour éventuel) et sur des enquêtes de terrain multi-situées (Centrafrique, Cameroun, Tchad). Une première partie démontre que les violences ne sont pas causées par la faiblesse de l'État centrafricain, mais par les politiques de ses dirigeants. Les populations sont prises pour cible dans des conflits irréguliers pour contrôler l'appareil d'État et par des groupes armés qui pillent les ressources (bétail, récoltes, infrastructures publiques, diamants). Une seconde partie montre que si les insécurités jouent sur l'ampleur, la répartition spatiale et la durée des exils, les migrants orientent leurs cheminements selon leurs habitudes circulatoires. Ils empruntent divers champs de mobilités pour fuir les violences (mobilités agricoles et pastorales, relations villes-campagnes). Une troisième partie met en perspective le rôle de l'aide humanitaire et des politiques d'asile dans la production de l'espace migratoire, autour de deux formes d’accueil : les camps de réfugiés, la dispersion des migrants dans des villes et des villages. / Since 1996, armed conflicts, organized crime (road bandits) and raids have forced hundreds of thousands of Central African Republic people to migrate within their own country (IDPs) or to bordering countries (refugee in Cameroon and Chad). Through various geographical schools (political, development, mobility), this work demonstrate that forced migrations results from both the practices of migrants and the political choices or the supervisory organizations (states, armed groups, humanitarian organizations). It is based on a transversal approach of forced migration (ranging from the starting point of the migrant up to his possible return) and multi-located field surveys (CAR, Cameroon, Chad). The first part shows that violence is not caused by the weakness of the CAR state, but by the policies of its leaders. The populations are targeted in the course or irregular conflicts aimed at controlling the political machinery and by armed groups plundering ressources (livestock, crops, public infrastructure, diamonds). The second part shows that if insecurities influence the extent, the spatial distribution and the duration of exiles, migrants direct their paths according to their regular circulations. They use various fields of mobility to escape violence (agricultural and pastoral mobility, urban-rural relationship). A third part put sinto perspective the role of humanitarian aid and asylum policies in the production of the migratory space (refugee, camps, dispersion of migrants).

La diversité biologique du continent africain incite à explorer les sources multiples de la variation qui façonnent la morphologie humaine. La morphométrie, outil complémentaire à la génétique explore la diversité actuelle et passée. Cette recherche a donc pour objectif de réexaminer, en lien avec divers facteurs (phylogénie, géographie, climat, histoire), la variation morphologique en Afrique centrale, région clé pour comprendre l’histoire du continent. Jusqu’à présent, des études craniométriques ont été réalisées avec des méthodes bidimensionnelles sur des crânes complets en incluant rarement les collections archéologiques fragmentaires. L’objectif est aussi de palier à ce problème, en analysant le crâne dans son ensemble versus l’os temporal, qui a l’avantage de bien se conserver et contenir des informations surtout d’ordre phylogénétique. Un échantillon de 147 restes crâniens d’Afrique centrale a donc été sélectionné. Les individus récents (137 crânes complets) sont originaires de diverses localités réparties sur une zone géographique de 760 000 km2. Les individus archéologiques (11 os temporaux) proviennent de deux sites: Shum Laka, Cameroun (7 000 – 3 000 BP) (n=2); et Dépression de l’Upemba, D.R.C. (1 300 BP) (n=9). Après avoir créé une banque de modèles virtuels via la photogrammétrie, la morphométrie géométrique 3D a permis d’analyser séparément le crâne et l’os temporal. Après avoir vérifié la faible influence du dimorphisme sexuel, les résultats ont relevé quatre points : I) La morphologie crânienne actuelle, analysée dans sa globalité, reflète bien divers aspects phylogénétiques (appartenance ethnique) et environnementaux (géographie, climat) et possiblement d’ordre historique (mouvement de populations). II) La morphologie de l’os temporal, pris isolément, reflète aussi une variation inter-populationnelle élevée. Cependant, comme les distances entre groupes sont relativement courtes, cela pourrait être expliqué par le fait que l’os temporal reflète surtout la phylogénie. III) Une continuité de certains traits morphologiques de l’os temporal à travers le temps a été détectée, particulièrement au sein du groupe datant de l’âge du fer (Dépression de l’Upemba). IV) Finalement, une possible adaptation anatomique à des pressions environnementales (alimentation, économie) a été observée, notamment au niveau de la forme de la fosse mandibulaire de l’os temporal, passant d’une forme circulaire à une forme ellipsoïde depuis l’âge de pierre tardif à la période récente. / The biological diversity of the African continent impels us to explore the multiple sources of variation that shape human morphology. Morphometry, a complementary tool to genetics, explores current and past diversity. Therefore, by exploring various factors (phylogeny, geography, climate, history) this research aims to re-examine the morphological variation in Central Africa, a key geographical region for understanding the history of the continent. Thus far, craniometric studies have been carried out with two-dimensional methods on complete crania, and rarely included fragmentary archaeological collections. The aim of this research is also to overcome this problem, by analyzing the whole cranium versus the temporal bone. The latter has the advantage of an exceptional state of preservation and provides information of phylogenetic nature. Therefore, a sample of 147 crania from Central Africa was selected. Recent individuals (137 complete crania) originating from various localities spread over a geographical area of 760,000 km2. The archaeological sample (11 temporal bones) originates from two sites: Shum Laka, Cameroon (7,000 – 3,000 BP) (n=2); and Upemba Depression, R.D.C (1,3000 BP) (n=9). After creating a 3D models database using photogrammetry, 3D geometrics morphometrics was performed to analyze separately crania and temporal bones. Results demonstrate a weak influence of sexual dimorphism on morphology and raise four points: I) The analysis of current cranial morphology reflects various phylogenetic (ethnicity), environmental (geography, climate), and possibly histological (movement of populations) aspects. II) The morphology of the temporal bone also reflects a high inter-population variation. However, because distances between groups are relatively short, this could be explained by the fact that the temporal bone reflects mostly phylogeny. III) A continuity of some morphological traits of the temporal bone through time has been detected, particularly in the Iron Age group (Upemba Depression). IV) Finally, a possible anatomical adaptation to environmental pressures (diet, economy) was observed, especially in the shape of the mandibular fossa of the temporal bone, changing from a circular form during the LSA to an ellipsoid form in recent times.