Seed coats of cream-coloured Bechuana white and purple-coloured Agriblue cowpea varieties and the freeze-dried forms of their acetone extracts (CPE) were analysed for total phenol content using the Folin-Ciocalteu and Ferric Ammonium Citrate methods. The seed coats and CPE of both cowpea varieties were analysed for antioxidant activity using the Trolox Equivalent Antioxidant Capacity (TEAC) assay. HPLC (High Performance Liquid Chromatography) was done to determine the free phenolic acid composition of the CPE. The effect of the seed coats and CPE on the peroxide value (PV) of sunflower oil was determined during storage at 65oC over a 16-day period. The seed coats and CPE were added to the sunflower oil at concentrations of 1800 ppm and 900 ppm and their effect compared to that of the synthetic antioxidant tertiary butyl hydroquinone (TBHQ) added to the oil at 200 ppm. Seed coats and CPE fromBechuana white cowpeas contained higher levels of total phenols than the corresponding samples of Agriblue. This differed from the generally observed trend that cowpeas with darker-coloured seed coat generally contain higher levels of total phenols than light-coloured cowpeas. More cowpea varieties need to be tested to confirm this observation. The ABTS•+ radical scavenging activity of the seed coats and CPE of Bechuana white cowpeas were higher than those of Agriblue. According to the HPLC chromatograms, both cowpea varieties had similar types of phenolic acids namely, the cinnamic acid derivatives p-coumaric, ferulic and sinapic acids and the benzoic acid derivatives p</i<-hydroxybenzoic acid, 3,4 dihydroxybenzoic, syringic, gallic and vanillic acid. These were present in higher amounts in Bechuana white than Agriblue. Phenolic acids derived from cinnamic acid tend to have higher antioxidant activity than benzoic acid derivatives. The higher antioxidant activity of Bechuana white seed coat acetone extracts and CPE was attributed to the presence of phenolic acids, especially the cinnamic acid derivatives in higher amounts in Bechuana white than Agriblue. CPE and seed coats of both cowpea varieties reduced the formation of hydroperoxides in sunflower oil as shown by their lower peroxide values compared to oil without added antioxidant during storage. This antioxidant effect of the additives was attributed to the presence of phenolic compounds. The ability of the CPE and seed coats of both cowpea varieties to reduce formation of hydroperoxides in sunflower oil was dependent on their concentration in the oil. However, the seed coat and CPE of both cowpea varieties were not as effective as TBHQ in reducing the formation of hydroperoxides in the oil. Bechuana white CPE and seed coats were more effective than Agriblue in reducing the formation of hydroperoxides. This was because Bechuana white had higher levels of total phenols and higher radical scavenging activity than Agriblue. For both cowpea varieties, the seed coats were less efficient in retarding the formation of hydroperoxides than the CPE. This was because the extracted phenolic compounds in the CPE were in a freer form to diffuse in the oil to exert antioxidant effects compared to the unextracted seed coat. / Dissertation (MInst.Agrar (Food Production and Processing))--University of Pretoria, 2007. / Food Science / unrestricted

The importance of micro and small enterprises (MSEs) is increasingly being recognized in many countries including South Africa after many years of market domination by large enterprises. Several initiatives are now being taken in South Africa to redress past discrimination and improve MSE development. However, MSE participation in markets is still low as shown by their market share and contribution to Gross Domestic Product. This is due to barriers they experience when attempting to participate in markets. These barriers may be due to the size of the enterprises, characteristics of the owners or managers and the environment in which they operate. The creation of a conducive environment to MSE market participation is essential to improve their participation in markets. This conducive environment will have few or no barriers to MSE market participation. Few studies have evaluated the institutional environment surrounding small businesses. Little research has been carried out to assess the conduciveness of the South African economy to MSE market participation. The general objective of this study is to assess the conduciveness of the South African economy to MSE market participation. The study analyzes policies and programmes that have been implemented to promote small business development. Factors influencing MSE market participation are identified and used to measure the conduciveness of the South African economy to these enterprises’ participation in markets. The factors are technology, finance, infrastructure, human resource development, strategic alliances, information and the regulatory environment. For each factor, South Africa is allocated a score out of ten, using data obtained from the World Economic Forum (WEF) survey carried out between 2003 and 2004. An analysis of policies and programmes such as the Broad-Based Black Economic Empowerment Act (2003), the Microeconomic Reform Strategy (2001) and the White Paper on Promotion of small businesses in South Africa (1995) indicates that they have helped to provide a conducive environment for MSE market participation. Policies and programmes such as the Rural Development Programme (1994), Growth and Employment Redistribution (1995) and the Green Paper on Public Sector Procurement Reform (1997) have not helped much to improve the conduciveness of the South African economy to the participation of MSEs in markets. The overall score for the conduciveness of the South African economy to MSE market participation is 6.6. This means that the South African economy is conducive to MSE market participation. Factors like finance, strategic alliances and the regulatory environment that have an average score of 7.6, make the South African economy more conducive to MSE market participation than factors like human resource development, infrastructure and technology which have an average score of 5.6. Access to information has the lowest score which is less than five. Regarding access to information by MSEs, the South African economy is not conducive to MSE market participation. The study makes recommendations on how to improve the South African economy’s conduciveness to MSE participation in markets. These suggestions include improving infrastructure and access to information, reducing credit constraints facing MSEs, appropriate technology, eliminating unnecessary bureaucracy and red tape and finding ways to increase the participation of MSE operators in training programmes. / Dissertation (MSc Agric (Agricultural Economics))--University of Pretoria, 2007. / Agricultural Economics, Extension and Rural Development / unrestricted

The aim of this study was to investigate the effect of different carbohydrate sources, with rapid and medium fermentabilities, on the digestibility and rumen fermentability of Atriplex nummularia cv. De Kock fed to sheep. Maize was used as the medium fermentable carbohydrate source and barley as the rapid fermentable carbohydrate source. The trial ran in four sequential experimental periods using two groups of animals. The two groups stayed constant during the entire trial, one group receiving the maize treatment and the other the barley treatment. During each experimental period the groups of animals received different levels of the two carbohydrate sources. Each experimental period consisted of a digestibility trial and a rumen fermentation trial. Four different levels of supplementation were used, namely 0, 15%, 30% and 45%. Measurements included dry matter intake, water intake, percentage dry matter digestibility, percentage neutral detergent fibre digestibility, rumen pool sizes, rumen pH, rumen ammonia nitrogen and rumen volatile fatty acid production. Supplementation of A. nummularia cv. De Kock with an energy source tended to increase feed and water intake. The tendency of energy sources to increase dry matter and neutral detergent fibre digestibilities diminished when the level of supplementation was raised from 15% to 30% and from 30% to 45%. The results suggest that maize and barley supplementation at a level of 15% resulted in the highest incremental increase in dry matter and neutral detergent fibre digestibilities of A. nummularia cv. De Kock. The results also indicated that energy supplementation tended to increase dry matter intake and rumen fill. Rumen pools of dry matter, neutral detergent fibre and total nitrogen all increased with an increase in the level of supplementation. The tendency of energy supplementation to increase the different rumen pools diminished as the level of supplementation increased from 30% to 45% for both the energy sources. The results also indicate that the rumen environment was more favourable for fibre degradation when maize was used as an energy source. In the final phase it is reported that ruminal ammonia nitrogen increased as the rate of supplementation was increased from the 0% to the 15% level. The drop in rumen ammonia nitrogen as the rate of supplementation was increased to 30% indicates an improvement in microbial protein synthesis. Ruminal pH decreased as the rate of supplementation increased with barley supplemented animals having lower rumen pH values. The decrease in rumen pH supports the increase in volatile fatty acid production as the level of energy supplementation was increased. It is concluded that an energy supplement of maize or barley will increase the intake and digestibility of A. nummularia cv. De Kock and that a level of 30% should be optimal for microbial protein synthesis without significantly affecting fibre degradation. / Dissertation (MSc Agric (Animal and Wildlife Sciences))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

The purpose of this study was to determine, understand and describe the acceptability, choice and preference of dairy fruit beverages by a group of black South-African female consumers. Food choice, acceptability and preference are complex and dynamic processes, influenced by various interrelated factors. The study was conducted in two phases. During the first phase a quantitative research approach was followed to collect demographic, purchasing and consumption information of the participants and to determine their hedonic responses towards the dairy fruit beverages by means of standardised sensory evaluation tests. A qualitative research approach was followed during the second phase of the study where focus group discussions were conducted to obtain supportive information for the interpretation and explanation of the data obtained during the first phase of the study. The target population for this study was black adult female consumers. They were chosen because of the high consumption and the popularity of dairy fruit beverages amongst them. The participants were selected from consumers who visited the School of Cookery at a large dairy company in Queensburgh in Kwa-Zulu Natal. The participants all spoke isiZulu and the majority completed Grade 12 or had a tertiary education. The participants were from Durban and surrounding areas. The average age of the participants was 35 years. The purchasing and consumption information revealed that the participants purchased dairy fruit beverages on average once a week from a local supermarket. The dairy fruit beverages were consumed more often in summer and with special occasions (such as birthday parties). The majority of the participants indicated that they preferred to purchase and consume a specific brand. The flavour purchased the most was the pineapple flavour. The results from the preference rating tests indicated that the main discriminating sensory attribute was taste and then flavour. The results from the preference ranking test indicated that the peach flavour was the most preferred fruit flavour. This was in contrast to the purchasing and consumption information which indicated that they mostly buy and consume the pineapple flavour. It was evident from the focus group discussions that all the participants were familiar with dairy fruit beverages and consumed it regularly. This was also supported by the demographic, purchasing and consumption information. The results from the focus group discussions confirmed that taste and appearance are important sensory attributes during food choice. The participants emphasised that the appearance must represent “…real fruit juice…” (it must not look like a soft drink) and must also smell like “…real fruit…”. It was clear that a high price is associated with good quality. Brand loyalty and social status were associated with the dairy fruit beverage brands, and indicated the powerful impact of mass media and advertisements on the perception and choices of dairy fruit beverages. Children were also mentioned as a persuading factor that influenced the choice and purchase of certain brands of dairy fruit beverages. This study contributed to understand and describe the consumer behaviour of the black female consumers in South Africa. The study added support to the implementation of strategic planning in the product development and marketing divisions of a food manufacturing company, to ensure that the consumer is satisfied and that expectations have been met. The quantitative and qualitative results supported and complemented another. Using both quantitative and qualitative research approaches are recommended when cross-cultural consumers in the South African context is the target population. / Dissertation (M Consumer Science (Food Management))--University of Pretoria, 2007. / Consumer Science / unrestricted

A predator-prey study was undertaken to determine the impact of lion Panthera leo predation on the declining populations of large ungulates in the Associated Private Nature Reserves, an open system with the Kruger National Park. The determination of prey population trends and their spatial distribution in relation to predator habitats are fundamental to studying predator-prey relationships. A combination of aerial counting and road strip censusing techniques were used to determine the prey population trends in the Associated Private Nature Reserves. The age and sex structure, habitat selection and seasonal abundance of the most abundant lion prey in the study area were compared with that of ungulate populations elsewhere in African savannas. The population dynamics of the lions in the Associated Private Nature Reserves were investigated by using the call-in counting technique. The total number of lions, mean pride size, lion density, and the age and sex structure of the lions in the study area was compared with that of lions in other African savanna woodland habitats. The range dynamics and habitat selection of four focal lion groups in the Associated Private Nature Reserves were studied. An adult lioness from each of the C, S and M prides, and an adult male from the N coalition were immobilized and then fitted with radio-collars. The range use and habitat selection of the lions in the present study were compared with that of their preferred prey, and with that of lions in other African savannas. In African savanna ecosystems, rainfall is regarded as the key component driving the system. Ecological modelling was therefore used to better understand the interrelationship between rainfall, prey population trends and lion predation in the Associated Private Nature Reserves. The overall conclusions of the ecological modelling were then compared with the results of the present study on lion predation in the Associated Private Nature Reserves. The predation rate and prey selection of the lions in the Associated Private Nature Reserves was determined by using a combination of short-term continual predation observations and historical lion kill data. The prey selection of the lions in the present study was compared with that of historical lion kill data to determine whether the predation pressure shifted from the preferred blue wildebeest and Burchell’s zebra to the more abundant impala, and the larger buffalo and giraffe. The killing and consumption rates of the focal lion groups in the present study were used to determine the impact of lion predation on the large ungulate populations in the Associated Private Nature Reserves. Lion predation data for the present study were compared with that of lions in other African savannas. The results of the present study were used to test the hypothesis that the apparent decrease in the large ungulate populations in the Associated Private Nature Reserves from 1980 to 2003 was due to a combination of lion predation, climatic fluctuation, the change in habitat over time, the removal of the boundary fences between the Associated Private Nature Reserves and the Kruger National Park, and the change in the aerial counting method from 1992 to 1996. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

This study was conducted on Tswalu Kalahari Reserve in the eastern Kalahari region of South Africa. The long-term sustainability of the valued African or Cape buffalo Syncerus caffer caffer was investigated in an area that falls outside their permanent historical distribution. The habitat utilisation of the buffalo population and their range use patterns were investigated. Seasonal differences were apparent in habitat utilisation and were guided by nutritional needs and climatic variables. Range use patterns revealed an increase in range size during the cold, dry season. The buffalo density on Tswalu was the lowest recorded in the literature to date with 0.15 buffalo/km². The animals showed seasonal changes in their feeding preferences with occasional browsing. During the cold, dry season the population was under severe nutritional stress. Population growth during the study period was 11.8% but this was within the norm expected for a free-living buffalo population. Annual recruitment for the study period was 33%, with half of the female population with calves at heel. However, the population is ageing with 54.2% of the population in the adult age class. Optimising the sex ratio and age structure could improve the productivity. Together with this, the nutritional needs of the buffalo should be met by supplementation, especially during periods of poor rainfall, to assist in optimal production and survival. Population viability analysis showed that the population is vulnerable over the medium term. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

Before 1994 the Department of Correctional Services was not representative of South African demography in terms of race, gender and disability. The challenge faced by the post-1994 Department of Correctional Services was to bring about change. The Department had to accept this challenge with full awareness of past and continuing discriminatory policies and practices and inadequate service delivery (Department of Correctional Services: Equity Policy, 1999:2). This study investigated the role of transformation in the reform of policies in the provision, maintenance and education, training and development of personnel in the Department of Correctional Services: Pretoria Central Prison. A qualitative research method was used in the study. The study involved survey questionnaires, survey interviews, a review of the relevant literature on the research topic and observation. The study shows that there has been an increase in the representation of blacks (coloureds and Africans) and women in the staff at Pretoria Central Prison. It is recommended that the Prison focus on increasing the representation of Indians and disabled persons to achieve the goals of transformation even further. / Dissertation (MAdmin (Public Administration))--University of Pretoria, 2007. / School of Public Management and Administration (SPMA) / unrestricted

The P300 serves as a valuable tool in examining higher auditory functions such as auditory attention and discrimination. Exploration of the P300 could be of value in a multi-lingual South Africa where auditory processing evaluations still rely heavily on inappropriate linguistically dependent tests. The P300 could potentially provide an objective, non-linguistically dependent evaluation of auditory processing. The present study aimed to investigate the influences of gender on the Auditory P300 Event Related Potential (AERP) and to contribute to establishing a clinic-specific normative database. One hundred subjects (n=100) (50% male) with normal hearing and no history of psychiatric illness were evaluated using the “odd-ball” paradigm. The averages and ranges of the findings on latencies and amplitudes were reported. The average latency values for the P300 were calculated at 314.7ms with a standard deviation of 37.2 ms. The average amplitude values were calculated at 7.1 µV with a standard deviation of 6.1 µV. No significant gender effect was found. In conclusion further research is recommended to explore the clinical utility of the P300 in different age and gender groups, using different protocols. / Dissertation (M (Communication Pathology))--University of Pretoria, 2007. / Speech-Language Pathology and Audiology / unrestricted

The purpose of the study was to evaluate the EAP’s internal marketing strategy in the National Prosecuting Authority. The study was conducted at the Head Office in Pretoria. The sample comprised of one hundred and three (103) employees of the NPA, representative of all business units in the organisation. The sample was drawn from the population using stratified random sampling method. The required number of respondents was further selected proportionally from each stratum using random sampling. The research approach followed in the study was a combination of qualitative and quantitative approach, dominant-less-dominant survey design. The research approach was predominantly quantitative, and a small qualitative component was incorporated, which aimed to explore one aspect of the study where respondents were required to give recommendations for improvement of the EAP internal marketing strategy within the organisation. A theoretical background on EAP internal marketing was provided through a literature study. In the literature study, the goals, objectives and elements of EAP marketing were discussed. The aspects of EAP that are critical for EAP marketing were explored and discussed. The literature study also included a discussion of various EAP marketing strategies. A practical review of marketing strategies employed by four companies was done in order to compare with the strategies implemented in the organisation where the study was conducted. The section concluded with the discussion of challenges of developing an internal marketing strategy. The empirical part of the study focused on the evaluation of the Employee Assistance Programme internal marketing strategy in the National Prosecuting Authority. The aim of the study was to determine whether the internal marketing strategy implemented was effective. A questionnaire was used as a research tool and distributed to the respondents. The findings of the study were based on ninety-nine (99) questionnaires that were returned by respondents. The findings were presented and analysed using tables and graphs, and also interpreted in words. The study revealed that generally, respondents were aware of the existence of the EAP. However, there is a great need to improve on the EAP internal marketing strategy in order to increase awareness of the different components and services of the programme. The hypothesis of the study was that marketing activities improve knowledge of EAP services amongst employees. The results of the study supported the hypothesis since respondents that were exposed to various EAP marketing material and methods of communication were aware of the different aspects of the programme than respondents who were not exposed Based on the findings of the study, conclusions and recommendations were made regarding the improvement of the EAP marketing strategy in the NPA. / Dissertation (M Soc.Sci (EAP))--University of Pretoria, 2007. / Social Work and Criminology / unrestricted

Increasing prominence is given to the role of optimization in engineering. The global optimization problem is in particular frequently studied, since this difficult optimization problem is in general intractable. As a result, many a solution technique have been proposed for the global optimization problem, e.g. random searches, evolutionary computation algorithms, taboo searches, fractional programming, etc. This study is concerned with the recently proposed zero-order evolutionary computation algorithm known as the particle swarm optimization algorithm (PSOA). The following issues are addressed: 1. It is remarked that implementation subtleties due to ambiguous notation have resulted in two distinctly different implementations of the PSOA. While the behavior of the respective implementations is markedly different, they only differ in the formulation of the velocity updating rule. In this thesis, these two implementations are denoted by PSOAF1 and PSOAF2 respectively. 2. It is shown that PSOAF1 is observer independent, but the particle search trajectories collapse to line searches in n-dimensional space. In turn, for PSOAF2 it is shown that the particle trajectories are space filling in n-dimensional space, but this implementation suffers from observer dependence. It is also shown that some popular heuristics are possibly of less importance than originally thought; their greatest contribution is to prevent the collapse of particle trajectories to line searches. 3. A novel PSOA formulation, denoted PSOAF1* is then introduced, in which the particle trajectories do not collapse to line searches, while observer independence is preserved. However, the observer independence is only satisfied in a stochastic sense, i.e. the mean objective function value over a large number of runs is independent of the reference frame. Objectivity and effectiveness of the three different formulations are quantified using a popular unimodal and multimodal test set, of which some of the multimodal functions are decomposable. However, the objective functions are evaluated in both the unrotated, decomposable reference frame, and an arbitrary rotated reference frame. 4. Finally, a practical engineering optimization problem is studied. The PSOA is used to find the optimal shape of a cantilever beam. The objective is to find the minimum vertical displacement at the edge point of the cantilever beam. In order to calculate the objective function the finite element method is used. The meshes needed for the linear elastic finite element analysis are generated using an unstructured remeshing strategy. The remeshing strategy is based on a truss structure analogy. / Dissertation (MEng (Mechanical Enigneering))--University of Pretoria, 2007. / Mechanical and Aeronautical Engineering / unrestricted