Abstract Background: The ability of the host immune system to efficiently clear Plasmodium falciparum parasites during a malaria infection depends on the type of immune response mounted by the host. Study design: In a cross-sectional study, we investigated the cellular-and antibody responses in individuals with P. falciparum infection, in an attempt to identify immunological signs indicative of the development of natural immunity against malaria in Ibadan, Nigeria. Levels of IL-10, IL-12(p70)...
Abstract 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 inv...
ABSTRACT The Natal Valley is a sediment-filled marine basin situated between the east coast of southern Africa (Natal) and the Mozambique Ridge. Geophysical and sedimentological t~chniques are used in a broad geological study of the mid Natal Valley. Major emphasis is directed to: (a) basin history and tectonic evolution; (b) seismic stratigraphy of the basin fill; (c) recent sedimentary processes and responses. General basin morphology is defined by five major physiographic provinces: contin...
In the blood vascular system of a typical fish, the blood is sent from the heart to the gills for oxygenation and thence to the rest of the tissues, before returning once more to the heart. This is a so-called "Single Circulation". Where lungs make their appearance in the vertebrate series however, their blood supply is derived from the last of the aortic arches and is returned via the newly formed pulmonary veins, directly to the heart. A part of the blood leaving from the heart is sent to t...
Abstract Background: Some MSP-119 specific antibodies that inhibit merozoite invasion also inhibit the secondary processing of MSP-1. However the binding of these inhibitory antibodies can be blocked by another group of antibodies, called blocking antibodies, which recognize adjacent or overlapping epitopes, but themselves have no effect on either MSP-1 processing or merozoite invasion. These antibodies have been reported to be present in individuals living in a malaria endemic area. Methods:...
Securities were first traded in the sixteenth century and it is reasonable to assume that si~ce that time investors have always devoted attention to research into the relative merits and demerits of individual stock market ventures. In the nineteenth and twentieth centuries, ma~ has placed increasing emphasis on numerical and statistical analysis, and it was only a matter of time before these two related approaches focussed their attention on the problems of stock market research. As early as...
Abstract Using the concept of parallel transport of vectors in curved manifolds, the Riemann curvature tensor in terms of Christoffel symbols is obtained. Making use of the Riemann curvature tensor’s symmetry properties, the Ricci curvature tensor and Einstein’s tensor are derived. Through Einstein’s tensor and the Poisson equation for Newtonian gravity, the Einstein field equations are introduced. Upon using Kerr metric (Kerr, 1963) as a solution for Einstein’s field equations, extra...
Abstract This dissertation presents an application of multicriteria decision analysis to understand and support pricing decisions in fields where goods are unique and described by their characteristics. The specific application area of this research is antique silver objects, where a complete iteration of the multicritia decision process is performed. This includes two problem structurings using SODA which provide rich detail into this application area. Multi-attribute additive models are con...
Abstract Sequential Nonparametric Estimation via Hermite Series Estimators Michael Jared Stephanou Algorithms for estimating the statistical properties of streams of data in real time, as well as for the efficient analysis of massive data sets, are becoming particularly pertinent given the increasing ubiquity of such data. In this thesis we introduce novel approaches to sequential (online) estimation in both stationary and non-stationary settings based on Hermite series density estimators. In...
Teaching indigenous knowledge (IK) to African youth has become more complicated due to a variety of reasons such as urban migration, loss of interest in it, the dominance of scientific knowledge and the technological revolution. Therefore, there is a considerable movement towards using technologies to safeguard IK before it becomes obsolete. It is noteworthy that research conducted and software development perspectives being used are mainly based on Western worldviews that are inappropriate f...
Abstract This work investigated the corrosion resistance of zinc-plated low carbon steel in cocoa fluid. Low carbon steel samples were zinc electroplated at voltages between 0.5 V and 0.9 V for 5–20 min. The plated samples were then subjected to a cocoa fluid environment for 30 days. The electrode potentials mV (SCE) were measured every day. Weight loss was determined at intervals of 5 days for the exposure period. The result showed corrosion attack on the zinc-plated steel, the severity in...
ABSTRACT In times of fossil fuel shortage, increasing crude oil prices, as well as rejection of conventional energy sources (e.g. coal or nuclear power plants), sustainable energy forms become more and more the focus of attention. One of several offered solutions is to develop a photovoltaic device (solar cells), since solar energy is abundant. Especially, Namibia receives solar radiation of 5.8 to 6.4 KWh per square meter per day – one of the highest in the world. With 8 to 11 average hou...
ABSTRACT The corporate world was faced with the challenge of community development. As a result, Namibian companies have been offering scholarships to assist students as best as they can. It was however an insurmountable task to assist the populace without clarity of information or background knowledge. Consequently, the selection of students for scholarships was arguably questionable. Some students awarded scholarships were from rural areas and others from urban areas. However, notice had t...
Abstract Gold extraction from different type of ores is largely driven by elemental compositions and gold particle size and distribution. Another major factor that contribute to inaccurate gold analysis/ estimation is the nugget effect (presence of gold particulates in different sizes and shapes). Therefore the purpose of the study was to quantify and evaluate the effect of different elements on gold extraction/analysis, establish gold particle size distribution and determine the most suitab...
Abstract To study the optical and photocatalytic properties of zinc oxide (ZnO or zincite), thin films doped with metallic silver-nanoparticles (Ag-NPs), with various amounts of Ag (20 mol% ≤ n ≤ 80 mol%), were fabricated on a quartz glass substrate at 600°C in air using the molecular precursor method (MPM). The fabricated thin films were analysed and X-ray diffraction (XRD) patterns of Ag nanoparticles, zinc oxide, and composite AgNP/ZnO films were measured using an X-ray diffractomete...