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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

An investigation into the potential immunogenicity of various extracts of the South African bont tick Amblyomma hebraeum

Adamson, Deborah Jane January 1993 (has links)
Rabbits and goats were inoculated with crude, membrane-associated and soluble components extracted from unengorged adult females and nymphs of the bont tick Amblyomma hebraeum. Inoculation provided some protection against nymphal infestation, however it had little effect on adult feeding. Histological examination of adults fed on inoculated hosts showed evidence of gut damage. Skin provocation testing with tick extracts elicited a Type I immediate hypersensitivity which was influenced by antihistamine. A delayed skin reaction was also evident. Whether this was attributable to Type III Arthus reaction or Type IV cell-mediated hypersensitivity was not determined. A comparative histological study of sites of tick extract injection, on inoculated and naive hosts, demonstrated the role of eosinophils in the hosts response to tick feeding. Serological examination revealed elevated anti-A hebraeum lgG titres following inoculation. These titres were found to decrease in the ten weeks after inoculation, despite the hosts being repeatedly infested with A hebraeum. Although the IgG titres of naive control hosts increased after each tick infestation, they failed to reach the titres achieved through inoculation. Western blot analysis of serum from inoculated hosts recognized most of the A. hebraeum proteins against which it was screened.
162

The engineering benefits of urban densification

Van der Walt, Tjaart Andries 12 September 2012 (has links)
M.Phil. / In order for developers to provide reasonable engineering services as well as a liveable dwelling unit within the existing housing subsidy, a substantial increase in residential density is required. Increased urban densities will decrease engineering services costs due to a greater sharing ability. This study was undertaken in order to quantify the benefits of urban densification on engineering services. The financial problems of Local Authorities in South Africa due to the entrenched culture of non-payment for services, is causing a rapid decline in the sustainability of engineering services due also to low, or non-existent maintenance. The "housing" currently delivered, its nature and continued sustainability are being severely criticized. Few differences exist between the housing currently being delivered and those provided under the previous government. Houses are provided in areas on affordable land normally far from the work place. The type of housing being constructed consists mostly of the single storey, free standing units on separate erven. These types of developments encourage urban sprawl, require very expensive engineering services and discourage the establishment of an economic public transport system. Possible solutions to the workforce/job opportunity problem include mixed land use and residential densification.
163

A biosystematic study of the genus Sutherlandia Br. R. (Fabaceae, Galegeae)

Moshe, Dineo 16 August 2012 (has links)
M.Sc. / A biosystematic study of the genus Sutherlandia (L.) R. Br., a poorly studied genus with confusing geographical variants, is presented. The species of Sutherlandia are all endemic to southern Africa. The species are very closely related and problems regarding their taxonomy are discussed. A few morphological characters that are useful in distinguishing amongst species are illustrated and discussed in detail. Morphological data are used to investigate infrageneric relationships in a phenetic analysis of 51 geographically separated populations. Sutherlandia has traditional medicinal uses, mainly as an anti-cancer treatment for internal cancers and as a general tonic. A survey of chemical compounds was done and the results are illustrated and presented in tables. The nature of this study did not allow detailed medical investigations, but the medicinal value of Sutherlandia and the compounds detected are highlighted. It is suggested that the anti-cancer activity can mainly be ascribed to the high levels of canavanine, a non-protein amino acid, in the leaves of the plant. Canavanine, an arginine analogue, is known for its antitumourigenic properties. The value of the plant as a bitter tonic is probably related to the presence of several triterpenoids, some of which may well also have other beneficial effects. Enzyme electrophoresis was done to explore genetic relationships amongst the numerous regional forms of Sutherlandia. A study of 19 populations showed that they are all closely related and that a more conservative treatment of the taxa is called for. As a result the number of taxa is reduced. A complete taxonomic revision of the genus is presented. The number of species is reduced from six to two, namely S. frutescens and S. tomentosa. The former is divided into three subspecies, namely subsp. frutescens, subsp. microphylla and subsp. speciosa. Some regional forms are described and illustrated, but these are not formally recognised as taxa. A key to the species, subspecies and regional forms is provided, and the. nomenclature, typification, description and geographical distribution for each of the taxa are given. The multidisciplinary approach of this study provided a better understanding of the morphological, chemical and genetic variation in this relatively poorly known but potentially valuable ornamental and medicinal plant.
164

A marketing profile of the Asian consumer market

Rau, N. 14 August 2012 (has links)
M.Comm. / Marketers have historically found it convenient to bundle the Asian consumer market together with the black consumer market or the white consumer market depending on the product or event under consideration. As we move toward an era of customised products and individualised service, minority markets become more difficult to overlook. Their unique characteristics demand that they be targeted as separate and unique market segments distinct from the mass markets that dominate the marketing environment.
165

Die radikale geskiedskrywing oor Suid-Afrika : 'n historiografiese studie

Verhoef, Grietjie 01 September 2015 (has links)
M.A. / Marxist historiography started during the late sixties and early seventies in response to the so-called "crisis" in the social sciences. The inability of these sciences to explain prolonged poverty and backwardness in areas of capitalist development and dependency in areas in close connection with the capitalist core, directed social scientists towards Marxist explanations. The conventional explanation of the implacability of capitalist development with racial stratification no longer rendered any explanation of Third World circumstances, since, especially in the South African case, the economy maintained high growth rates in spite of and under circumstances of sustained and intensified racial differentiation...
166

Die inhoud van die misdaadbegrip in die Suid-Afrikaanse strafreg

Badenhorst, Casper Hendrik Jacobus 13 August 2015 (has links)
LL.D. / Please refer to full text to view abstract
167

A critical overview of regional trade integration: lessons from COMESA

Umurungi, Francine January 2005 (has links)
Magister Commercii - MCom / The aim of this study was to determine which strategy would be most appropriate to enhance regional trade integration in COMESA so that it can provide to its member states the benefits they expect to have from it. / South Africa
168

Privatisation and deregulation policies in South Africa

Mfuku, Nkosana January 2006 (has links)
Masters in Public Administration - MPA / This research report examined the key policies of globalisation namely, privatisation and deregulation of services and also their implication on the Tri-partite alliance. Because they have impacted negatively on major economic sectors, particularly to those that help the needy. Therefore, the study explores these initiatives, which has been debatable in South Africa under the dominant understanding of ‘progress’ or ‘development’. The Objective of the study is to lay the basis for the examination and evaluation of policy option with regard to privatisation and deregulation of services in South Africa and to engage South Africa effectively in global policy debates and adjust in global trends and negotiations within the region (SADC) and other international countries. It examines global challenges and opportunities / threats for South Africa as a developing country in the emerging global order. This study also attempts to provide answers to several questions concerning privatisation and deregulation of public services in South Africa. To the poor, is deregulation and privatisation of state assets threatening to become the new apartheid, which is an instrument of exclusion, not just from a better life but even from the very basic services? How are workers and including the poorest of the poor affected by the status of deregulation and privatisation? Do the timing and specifics of these processes matter? Who should attempt to regulate the auction, as some of government officials seems to be corrupt? And which prior restructuring policies are worth implementing? / South Africa
169

Petrographic characterization of sandstones in borehole E-BA1, Block 9, Bredasdorp Basin, Off-Shore South Africa

Van Bloemenstein, Chantell Berenice January 2006 (has links)
Magister Scientiae - MSc / The reservoir quality (RQ) of well E-BA1 was characterized using thin sections and core samples in a petrographic study. Well E-BA1 is situated in the Bredasdorp Basin, which forms part of the Outeniqua Basin situated in the Southern Afircan offshore region. Rifting as a result of the break up of Gondwanaland formed the Outeniqua Basin. The Bredasorp Basin is characterized by half-graben structures comprised of Upper Jurassic, Lower Cretaceous and Cenozoic rift to drift strata. The current research within the thesis has indicated that well E-BA1 is one of moderate to good quality having a gas-condensate component. / South Africa
170

A review of Southern African kimberlites and exploration techniques

Venter, Louis Johannes 04 October 2013 (has links)
The dissertation reviews the present knowledge regarding diamonds, from its formation in the lithospheric upper mantle at depths between 150 and 300 km, to its final valuation in terms of US$/carat by diamantaires in London, Antwerp, Tel Aviv and New York. The dissertation is divided into two complimentary sections. Section one focuses on the formation, emplacement, occurrence and characteristics of kimberlites and, when present, their associated trace amounts of diamonds. The section follows a logical sequence from the regional tectonic-, local structrual- and geodynamic controls on kimberlite formation and emplacement to the characteristics of individual kimberlite morphology, mineralogy, petrography and geochemistry. Finally, the environment or diamond formation, resorption and the characteristics that have led to the marketability of diamonds are discussed. Section two reviews the current exploration techniques used in locating diamondiferous kimberliies and the subsequent economic evaluation of these kimberlites. A brief history of known Southern African kimberlite occurrences, grades, tonnages, tectonic settings, ages and regional structural controls is given. The prospective countries mentioned are Angola, Botswana, Lesotho, South Africa, Swaziland, Tanzania and Zimbabwe. Exploration techniques considered are ; the application of a landscape analysis and investigation of the surface processes active in a given area, indicator mineral sampling (with reference to their mineralogy and exploration significance), remote sensing techniques (subdivided into satellite imagery and aerial photography), geophysical techniques (including the magnetic-, gravity-, electrical-, radiometric- and seismic methods as well as heat flow models), geochemical techniques, petrographic- and electron beam techniques as well as geobotanical- and geobiological techniques. Finally, a brief summary of current evaluation techniques employed on diamondiferous kimberlite deposits is presented. The review covers kimberlite sampling methods, sample processing, diamond grade distributions (with reference to the experimental variogram model, statistical methods used in grade distribution calculations as well as block definition and local grade estimation). Stone size distributions, including microdiamond counts and value estimation, are also discussed. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

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