Environmental variation of Thamnocortus insignis Mast. (Restionaceae) is presented, by using average dry weight measurements of six populations of this species found along the coast of the Cape Province. The dry weight measurements were used to detect variation in the growth rates of the six populations, which in tum indicates the environmental variation among the populations. The results were showed no significant difference between all six populations and this was due to the relatively very small sizes of the seedlings when the measurements were taken. Genetic variation was investigated by using isozyme electrophoresis of the EST locus. One population (Puntjie) showed significant deviation from the Hardy-Weinberg equilibrium, whilst all the others agreed with the assumptions of the model except for the Superthatch-extra tall population, which was homologous. Estimation of allelic diversity among the populations produced a Fst of 0.098 that implies that there is a high level of gene flow among the six populations of the species. The allelic diversity estimate within populations was also very low (Fis = 0.079) implying that the genetic neighbourhoods are relatively large and there is a high incidence of gene flow within the populations. Both estimation results support the predicted results for dioecious wind-pollinated species such as T. insignis.

Student Number : 0318625T - MSc dissertation - School of Molecular and Cell Biology - Faculty of Science / Genetic variation in haptoglobin, a plasma protein, has been reported to be associated with susceptibility to and the rate of HIV/AIDS progression. The purpose of this study was to investigate the influence of haptoglobin polymorphism on HIV/AIDS in black South Africans. Polymorphism in the coding region of the haptoglobin gene was detected by direct DNA and allele-specific amplification. Polymorphism in the coding region of the gene was detected by amplification of DNA and by polyacrylamide gel electrophoresis of plasma protein. A statistically significant association was observed between allele -61C and resistance to HIV infection. The Hp0 phenotype, in which no haptoglobin protein is detected, was associated with HIV status and some promoter genotypes. Since in our study population there were a few samples with usable clinical data , further investigations need to be done to confirm the association of the -61C allele and the Hp0 phenotype with the risk of HIV infection.

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The investigation of the waters of Lake Bridgeport is to obtain data essential for a satisfactory understanding of the physical and chemical factors on the aquatic life. These factors detremine the kinds of food available for life there.

Yes / Condition monitoring of micro injection moulding is an effective way of understanding the processing effects of variable parameter settings. This paper reports an experimental study that investigates the characteristics of the demoulding behaviour in micro injection moulding (A mu-IM) with a focus on the process factors that affect parts' quality. Using a Cyclic Olefin Copolyme (COC) microfluidics demonstrator, the demoulding performance was studied as a function of four process parameters (melt temperature, mould temperature, holding pressure and injection speed), employing the design of experiment approach. The results provide empirical evidences on the effect that processing parameters have on demoulding conditions in A mu-IM, and identifies combinations of parameters that can be used to achieve the optimal processing conditions in regards to demoulding behaviour of micro parts. It was concluded that there was a direct correlation between the applied pressure during part filling, holding phases and the demoulding characteristic factors of the A mu-IM cycle such as ejection force, integral and time.

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