Inaug.-diss.--München. / "Literaturverzeichnis": p. [127]-138. "Kartenverzeichnis": p. 138-141.

Inaug.-diss.--München. / "Literaturverzeichnis": p. [127]-138. "Kartenverzeichnis": p. 138-141.

Central Africa is, climatologically speaking, a poorly studied region (Clivar, 2000; Dezfuli and Nicholson, 2012; Nicholson and Dezfuli, 2012; Todd and Washington, 2004). It is considered as a knowledge gap in the understanding of the tropical climate system (Todd and Washington, 2004). Drivers of Central Africa rainfall are not well documented and deserve more attention. The aims of thesis are to enhance our fundamental understanding of Central Africa rainfall and the mechanisms involved in its seasonal and interannual variability as well as to assess how an atmospheric general circulation model forced by observed sea surface temperature (SST), the ECHAM5.3 model, does represent the main features of Central Africa hydroclimate variability. The seasonal cycle of Central Africa rainfall is primarily driven by change in the atmospheric low-pressure system of Central Africa landmass, water vapor and latent heat release rather than change of local temperature. From October to April, over Central Africa and its neighbouring regions, we highlight the existence in the mid-lower troposphere, between 1000 and 500 hPa of a dominant cyclonic and quasipermanent circulation pattern that drives the atmospheric large-scale circulation and its associated water vapor transports, namely the Central Africa Low. The Central Africa Low, with its variation strongly modulated by El Niño Southern Oscillations (ENSO), is characterized by strong convective activity due to an unstable atmosphere over central Africa, leading to high rainfall with less variance. Nevertheless, when the Central Africa Low prevails, Central Africa is a sink of water vapor, with the Indian Ocean as the main supplier. The weakening of the Central Africa Low, in May to September, is associated with the reversal of the water vapor transport at the northern boundary channel, leading Central Africa to become a source of moisture. During this season, both surrounding oceans are suppliers of moisture, with some additional contribution from the Congo basin rainforest. Central Africa rainfall variability is controlled by large-scale circulation variation, rather than variation in tropospheric water vapor. Year-round, the large-scale circulation is characterized by dominant easterly jets at middle (African easterly jets, AEJs) and upper (tropical easterly jets, TEJ) levels, owed by the Central Africa Low. At low-levels, there is a shallow zonal overturning circulation thermally direct, namely the Congo Basin Cell, driven by near-surface land-ocean thermal contrast between the warm central Africa landmass and the relatively cold Atlantic Ocean. The Congo Basin Cell, characterizes by eastward flow, persists year-round, with a maximum strength (-196.92±32.89 Sv) and width (30o degree) in August/September and minimum strength (-24.80± 17.83 Sv) and width (~6o degree) in May. The Congo Basin Cell does not play any crucial role in modulating Central Africa rainfall but it does regulate the rainfall distribution, through the seasonal position of the ITCZ. At midlevel, the atmospheric convective instability over Central Africa is controlled by the southward import of high moist static energy from the warmer Sahel associated with the AEJ over Central Africa. The saturation of the rising moist air at midlevel determines the location of high rainfall over central Africa year-round. Nevertheless, the absence of significant trend (- 0.013 mm per decade) of the Central Africa rainfall is associated with the weakening of the Central Africa Low in recent decades (1979 to 2015), consistent with Lau and Wu (2006). Further investigations on physical mechanisms affecting the Central Africa hydroclimate reveals that the Central Africa Low and land-ocean thermal contrasts are the main drivers of Central Africa rainfall variability at seasonal and interannual time scale, through the control of AEJs and the Congo Basin Cell strength and width. The analysis of ECHAM5.3 experiments provide a support to these mechanisms. Finally, to unravel what are the physical mechanisms shaping the rainfall anomalies patterns associated with the interannual variability of Central Africa rainfall, we found out that the Central Africa does reflect the regional-scale response of the atmosphere to the variation of the interbasin SST anomalies gradient (ΔSST) between tropical Atlantic and Indian Oceans. Likely, the zonal contrast of central Africa rainfall is owed by the Central Africa Low, which separates central Africa in two distinct regions of opposite polarity by regulating the strength of the low-level westerly and mid-upper easterly jets and their associated water vapor transports. This east-west dipole-like pattern of Central Africa rainfall is similar to the second leading mode obtained by empirical orthogonal functions (EOF) analysis of rainfall anomalies during the long rainy season. Thus, during the positive phase of ΔSST, the Central Africa Low area change induces an anomalous clockwise zonal overturning cell over Central Africa, with ascending branch over Atlantic, indicative of deep convection leading to rainfall surplus, and sinking branch over Indian Ocean, indicative of subsistence, which suppress convection and lead to rainfall deficit, consistent with the mechanism proposed by Dezfuli et al. (2015). However, the impact of ΔSST on Central Africa rainfall variability is asymmetrical during positive and negative phases of ΔSST.

Thesis (D. Th.)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

ABSTRACT Background: A variety of studies identified early sexual debut as a significant risk factor for HIV infection, particularly among young African women. However, little is known about this relationship in Central Africa. Methods: This study was based on a cross-sectional analysis of Demographic and Health Surveys data drawn from four central African countries, Cameroon and Gabon with high HIV prevalence levels, Democratic Republic of Congo and Congo with low HIV prevalence levels. Relationship between sexual activity initiated before age 15 and HIV sero-status was examined in men and women aged 15-24 years, to determine potential differences in this relationship across countries. Logistic regression was used to build a standard multivariate analysis model allowing for comparison between countries while controlling for sociodemographic, economic, behavioral, most recent partner characteristics, and HIV prevention knowledge. Results: HIV prevalences were significantly higher among women from high HIV prevalence countries compared to women living in lower HIV prevalence countries (p Conclusion: Decline in heterosexual transmission of HIV in Central Africa will necessitate that behavioral interventions targeting young African women encourage delaying sexual debut and not engaging in other risky sexual behaviors.

Texte remanié de: Doct. Thesis--Hist.--London--King's College, 2005. / Bibliogr. p. 235-264.

This is a study of the eastern Lunda kingdom of Kazembe, the political history of which has never received detailed treatment despite its indisputable regional significance between the mid-eighteenth and the mid-nineteenth century. This work differs from most monographic studies of the history of the eastern savanna of Central Africa in its attempt to examine both the pre-colonial and the colonial experiences of the Kazembe kingdom. This approach reflects awareness of the manipulability of historical consciousness and the extent to which oral sources were moulded by the colonial context. The implementation of a flexible set of symbols and institutions of rule was the principal contribution of the rulers of the Kazembe kingdom to the political transformation of the territory to the east of the upper Lualaba River. It enabled them to wield a measure of influence over peripheral societies in both southern Katanga and the plateau to the east of the lower Luapula valley, the heartland of the kingdom and an ecological niche conducive to the development of political complexity and centralization. The disparity between the articulations of political control in the heartland and the periphery, together with the role of long-distance trade and the growing importance of external influences and threats, are essential to understand the decline of the power of the eastern Lunda in the second half of the nineteenth century. It was a much enervated polity which faced British and Belgian empire-builders in the last decade of the century. The kingdom was easily subdued, but the aspirations of its rulers lived on throughout the colonial period. An examination of the interactions between Lunda leaders, British officials and subjects of both shows that the royal family was better placed than the aristocracy to take advantage of the new political circumstances and answer the challenges of economic change and mission education. The furtherance of a new ethno-history was another manifestation of the fundamental adaptability of the royal family.

Thesis (MTh)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Motivated by the observation that child labour is harmful to children, this research aims to determine whether child labour could be described as a violation of human dignity. The research further attempts to develop a theological framework which the Church of Central Africa Presbyterian (C.C.A.P) Synod of Livingstonia in Malawi could adopt in restoring the human dignity that might have been trodden on in child labour practices. In order to achieve the objectives of this study, eight ministers from two presbyteries were interviewed, using a structured questionnaire as the main tool for data collection. The data was analyzed using a thematic data analysis method. The findings indicated that child labour is any work done by children that is detrimental to their welfare. Such work was predominantly on tobacco farms both at commercial and at family levels, and was carried out under hazardous conditions. As a result children experience the following effects; physical abuse; psychological torture, sexual abuse; and these children may end up in perpetual poverty experiences, to mention just a few effects. The critical literature analysis done with reference to theological concept of human dignity, characterized the effects as a violation of human dignity. The main causes of child labour identified during this study were poverty, ignorance of short and long terms impact of child labour effects on children, and the cultural perceptions that children are equipped for the future if they are trained (socialized) to work hard at a tender age. By implication, as long as these causes exist, child labour may remain a problem and children may continue to suffer since these children do not enter labour by choice, but forced by the socio-economic and socio-cultural structures. Although these children experience this human degradation there is no way they can stop working on their own, because they do not have a voice, they are under the control of parents and employers. In this context this study would like to classify working children as among the marginalized, oppressed, weak and vulnerable groups in need of people and institution that can speak and act on their behalf. Therefore it is argued that there is a need for the church to advocate for the marginalized children in this context. The literature consulted further indicated that the church of Jesus Christ is responsible for providing spiritual and physical salvation to people, taking into account how long it may take to deal with some of the main causes of child labour. The church may consider its advocacy role of protecting the dignity of human beings created in the image of God with compassionate love. This research suggests recommendations that are in line with theological understanding of who the church is and the human dignity of people and specifically of children, to address the challenges of child labour practices. The recommendations attempt to involve different stakeholders of the community to work in a consortium. / AFRIKAANSE OPSOMMING: Die navorsing is gemotiveer deur die waarneming dat die gevolge van kinder-arbeid skadelik vir kinders kan wees, en stel dit ten doel om vas te stel of die effek van kinder-arbeid as ʼn skending van menswaardigheid beskryf kan word. Die navorsing streef ook om ʼn teologiese raamwerk te ontwikkel wat die Church of Central Africa Presbyterian (C.C.A.P) Livingstonia Sinode in Malawi kan gebruik om die menswaardigheid wat moontlik deur kinder-arbeid- gebruike vertrap is,te herstel. Ten einde die doelstellings van die studie te bereik, is onderhoude gevoer met agt predikante van twee ringe, Jombo en Rumphi, in Livingstonia Sinode. Tydens die individuele onderhoude is ʼn gestruktureerde vraelys hoofsaaklik gebruik vir die versameling van data. Die versamelde data is ontleed met ʼn tematiese data-ontleding metode. Volgens die bevindings is kinder-arbeid enige arbeid wat kinders verrig wat nadelig vir hul welsyn is. Die meeste werk wat deur kinders verrig word, is op kommersiële tabakplase of in familieverband op kleinboere se tabakplase. Die werk is meestal onder gevaarlike omstandighede. As gevolg van die gevaarlike werk, ervaar kinders fisiese mishandeling, sielkundige teistering, seksuele mishandeling en ook soms gedurige armoede, om net ʼn paar te nadelige effekte te noem. Die kritiese literatuur-analise oor hierdie effekte met verwysing na ʼn teologiese konsep van menswaardigheid, toon dat die gevolge gekenmerk kan word as skending van menseregte. Die volgende primêre oorsake van kinder-arbeid is in die studie geïdentifiseer: armoede, onkunde oor die kort- en langtermyn impak van kinder-arbeid op kinders, en kulturele persepsies dat kinders vir die toekoms toegerus word as hulle op ʼn jong ouderdom geleer word (sosialisasie) om hard te werk. Die implikasie is dat solank hierdie oorsake voortbestaan, sal kinder-arbeid ʼn probleem bly en sal kinders steeds so ly, aansien hierdie kinders nie kies om kinder-arbeid te verrig nie, maar deur sosio-ekonomiese en sosio- kulturele strukture daartoe gedwing word. Al word hierdie kinders onmenswaardig behandel, kan hulle nie ophou werk nie, want hulle het nie ʼn stem nie, hulle word beheer deur hul ouers en werkgewers. In hierdie konteks stel hierdie studie werkende kinders gelyk aan die klassifikasie van die gemarginaliseerde, onderdrukte, swak en weerlose groep namens wie mense en organisasies moet praat en optree. Daar word dus betoog dat daar ʼn behoefte is dat die kerk namens gemarginaliseerde kinders in hierdie konteks intree. Die literatuur dui verder aan dat die aard en missie van die kerk van Jesus Christus maak ons verantwoordelik om spirituele en fisiese verlossing vir mense te bied. In die lig van die uitdagings van kinderswat werk, en met inagneming van hoe lank dit mag neem om sommige van die oorsake van kinder-arbeid aan te spreek, kan die kerk sy rol in terme van die beskerming van die menswaardigheid van mense geskape in die beeld van God met deernisvolle liefde oorweeg. Die navorsing maak voorstelle wat belyn is met die teologiese verstaan van wie die kerk is en die menswaardigheid van mense en spesifiek van kinders, om die uitdagings van kinder- arbeid aan te spreek. Die aanbevelings streef om verskillende aandeelhouers in die gemeenskap te mobiliseer om as ʼn konsortium saam te werk om kinder-arbeid en die onmenswaardige behandeling van kinders te bestry.

In Central Africa, wildlife populations are increasingly influenced by humans, even in protected areas. This raises the question how spatial patterns of wildlife abundance are affected by human activities and habitat and how these patterns change over time. I address these questions by developing spatial models combined with line transect survey data in two forest sites in Central Africa. In the Odzala National Park in the Republic of Congo, I examine elephant dung abundance data in relation to human threats and protection. In the Okapi Faunal Reserve in the Democratic Republic of Congo (DRC), I developed spatio-temporal models for elephants and other forest ungulates to examine temporal changes in their densities as a result of changes in human impact in the context of a civil war that took place in the region between the two surveys. Covariates related to human influences dominated the observed patterns at both sites. In Odzala, elephant dung densities were mainly influenced by protection. They were higher inside the protected area and closer to anti-poaching patrol routes. In the Okapi Faunal Reserve, populations of all ungulate species declined severely between the two survey periods. Declines in elephant abundance were relatively higher closer to the park boundary and areas of intense human activity. After the war, elephant densities were higher in a small area in the centre of the park that may have acted as a refuge. Forest duikers also declined, but the spatial pattern of their decline was different than that of elephants. Densities dropped more in the southern part of the reserve, probably due to pre-exisisting higher levels of hunting there. Besides explaining spatial patterns of abundance, spatial modeling was shown to be useful in improving the precision of density estimates and in predicting densities across a surface in the Odzala National Park. In summary, humans overwhelmingly determined the distribution and abundance of ungulates in both sites. The civil war in DRC led to a dramatic increase in elephant poaching for ivory which caused a major decline in elephant populations. It aggravated the bushmeat hunting of duikers whose populations also declined sharply.

In Central Africa, wildlife populations are increasingly influenced by humans, even in protected areas. This raises the question how spatial patterns of wildlife abundance are affected by human activities and habitat and how these patterns change over time. I address these questions by developing spatial models combined with line transect survey data in two forest sites in Central Africa. In the Odzala National Park in the Republic of Congo, I examine elephant dung abundance data in relation to human threats and protection. In the Okapi Faunal Reserve in the Democratic Republic of Congo (DRC), I developed spatio-temporal models for elephants and other forest ungulates to examine temporal changes in their densities as a result of changes in human impact in the context of a civil war that took place in the region between the two surveys. Covariates related to human influences dominated the observed patterns at both sites. In Odzala, elephant dung densities were mainly influenced by protection. They were higher inside the protected area and closer to anti-poaching patrol routes. In the Okapi Faunal Reserve, populations of all ungulate species declined severely between the two survey periods. Declines in elephant abundance were relatively higher closer to the park boundary and areas of intense human activity. After the war, elephant densities were higher in a small area in the centre of the park that may have acted as a refuge. Forest duikers also declined, but the spatial pattern of their decline was different than that of elephants. Densities dropped more in the southern part of the reserve, probably due to pre-exisisting higher levels of hunting there. Besides explaining spatial patterns of abundance, spatial modeling was shown to be useful in improving the precision of density estimates and in predicting densities across a surface in the Odzala National Park. In summary, humans overwhelmingly determined the distribution and abundance of ungulates in both sites. The civil war in DRC led to a dramatic increase in elephant poaching for ivory which caused a major decline in elephant populations. It aggravated the bushmeat hunting of duikers whose populations also declined sharply.