The present study examined whether a relationship exists between level of rigidity and prejudicial attitudes and whether prejudiced attitudes could be modified as a function of exposure to a competent black model. It was predicted that individuals with a high level of rigidity would display more racial prejudice than low-rigid individuals and that individuals with a low level of rigidity would demonstrate less prejudice than high-rigid individuals after exposure to a competent model. After exposure to a competent model, a significant main effect for rigidity was found which indicated that low-rigid individuals became less prejudiced than high-rigid individuals,

Friction contact with both external and internal environments can significantly influence its efficiency, which could cause friction instabilities, vibration, and noise. Focusing on the effects that troubles brake pad, rotor, and friction-induced NVH, the main motivation for this study is to understand its drawbacks for some extent in a braking system. By proper study on applied statistics, an experimental design is planned. The design has friction tests that are performed by scaling down real test properties used in dynamometer to scaled-down properties in a subscale tester by using scaling law of physics. The test has two different types of rubbers with different humidity conditions with respect to two different brake pads in a small-scale tester, the Universal Mechanical Tester (UMT). This friction experiment helps in determining how different rubbers impact its stiffness on the coefficient of friction and noise levels, also to evaluate which scenario has the better damping capacity. The effect on the coefficient of friction and noise levels with and without rubbers is also compared. The results are subjected to the Design of Experiments analyses test know the statistical relationship between factors affecting the process and output of that process at different controllable variables namely humidity and temperature.

Canine Parvovirus remains a leading cause of enteritis in dogs in South Africa and many other countries despite the wide availability of effective vaccines. The virus does not affect all dogs equally and the course of the disease depends on the age, immune status and breed of the puppies as well as the viral dose, route of exposure and the virulence of the strain. Although aggressive supportive treatment can be successful, the treatment and convalescent periods may be prolonged and consequently expensive and the mortality rate relatively high, causing many clients to forego treatment and elect for euthanasia of their pet. Acute phase proteins (APP) are proteins that change in concentration by at least 25% in animals subjected to external or internal inflammatory challenges, such as infection, inflammation or surgical trauma. Increased concentrations are associated with poor outcome in certain diseases. C-reactive protein (CRP) is the most sensitive APP in dogs. Its normal physiological concentration is low but increases rapidly with inflammation or tissue destruction. Due to the fact that CRP has a relatively short half life in serum (6-8 hours) and a high response in diseased animals, it can be used as a valid measure of a systemic response to an initiating stimulus at the time of blood sampling. By taking serial measurements, objective information about the extent of the ongoing lesions in the patient can be obtained and therefore may be used as a prognostic indicator. The objective of this prospective observational study was to evaluate the association of serum CRP concentrations in puppies suffering from canine parvoviral enteritis with morbidity and mortality, and to determine the usefulness of CRP to predict duration of hospitalisation time. Seventy-nine client owned puppies naturally infected with canine parvovirus were included. Parvovirus infection was diagnosed on electron microscopic examination of faeces from the puppies. CRP was measured using an automated human C-Reactive Protein Turbidimetric Immunoassay (TIA), which has been validated for use in dogs. Serum CRP measurements were performed at admission, twice daily for the first 48 hours, then once daily until death or discharge. There was a positive association between odds of mortality and CRP concentration on admission, as well as 12 and 24 hours after admission (P=0.04,P=0.005 and P=0.003, respectively). Survival time was negatively associated with CRP concentration at 12 and 24 hours after admission (P=0.002and P=0.001, respectively). Among the survivors, length of hospitalisation was positively associated with CRP concentration at 12, 24 and 36 hours after admission (P=0.012, P=0.001 and P=0.002, respectively). Utility for CRP concentration to correctly differentiate between survivors and non-survivors at 24 hours after admission had a sensitivity and specificity of 78.7% and 86.7% respectively. Although serum CRP concentration is associated with outcome in puppies infected with canine parvovirus, when used alone it did not prove to be a good predictor of survival. / Dissertation (MMedVet)--University of Pretoria, 2012. / Companion Animal Clinical Studies / unrestricted

This study investigated the use of an advanced technological development (free GeoGebra software) within the secondary educational setting in four relatively under-resourced schools in the Gauteng Province of South Africa. This advancement is viewed as having the potential to promote the teaching and learning of complex ideas in mathematics, even within traditionally deprived communities. The focus in this study was on the teaching and learning of transformation geometry at Grade 9 and attainment was reflected in terms of the van Hieles' levels of geometrical thinking. A mixed methods approach was followed, where data was collected through lesson observations, written tests and semi-structured interviews. Four Grade 9 teachers from four schools were purposively selected, while twenty-four mathematics learners (six from each school) in the Tshwane metropolitan region were randomly selected. The teachers' lesson observations and interview outcomes were coded and categorised into themes, and the learners' test scripts were marked and captured. The analysis of test scores was structured according to the van Hieles' levels of geometric thought development. As far as the use of GeoGebra is concerned, it was found that teachers used the program in preparation for, as well as during lessons; learners who had access to computers or android technology, used GeoGebra to help them with practice and exercises. As far as the effect of the use of GeoGebra is concerned, improved performance in transformation geometry was demonstrated. / Dissertation (MEd)--University of Pretoria, 2016. / Science, Mathematics and Technology Education / MEd / Unrestricted

The aim of this study was to investigate the quality of the Annual National Assessment (ANA) Grade 6 mathematics instrument including its design, with reference to a single education district. The main question that was investigated was: To what extent does the 2012 Annual National Assessment Grade 6 mathematics assessment instrument provide meaningful information for making appropriate interpretations on district level? The conceptual framework underpinning this study was drawn from the Queensland Studies Authorities Assessment Policy document. The research comprised a secondary analysis design applying mixed methods using the scripts of 546 learners in one district from 5 schools selected to represent a range of achievement. A content analysis of the instrument was undertaken, followed by a statistical item analysis applying the Rasch measurement model. These analytical methods were utilised to determine the quality of the ANA Grade 6 mathematics instrument. Content validity, construct validity and reliability was investigated in order to evaluate inferences that were made and actions that were taken based upon the mathematics performance of learners in Grade 6 in the Gauteng North District (GND) in the year 2012. The investigation revealed that construct validity and content validity were largely achieved, as items were appropriately aligned to the 2012 ANA Grade 6 mathematics curriculum. However errors in mathematics and language formulation detracted from the validity of the instrument. In the case of some items, lack of clarity may have confused learners. As far as reliability is concerned the investigation revealed that the instrument had a reasonable person separation index, a measure of both item and person reliability. However, these conclusions are based on a relatively small sample from only one district and therefore has somewhat limited applicability but is nevertheless of educational consequence. / Dissertation (MEd)--University of Pretoria, 2017. / Science, Mathematics and Technology Education / MEd / Unrestricted

The value of the organisation’s credibility, reputation and interaction with customers equates to its relationship capital. Relationship capital defines the aptitude of an organisation to establish relationships in order to share information, knowledge, ideas, opportunities, contacts and referrals. However, the organisations as well as its personnel play a critical role in relational exchange and the quality of the relationship that is built with the customer. A strong positive relationship links relationship quality to suppliers, contact personnel and buyer’s loyalty by focussing on both the organisation and the individual commitments in a B2B relationship. The study seeks to determine the importance of organisational commitment and individual commitment in improving relationship quality within the Life Science industry. This is achieved by focusing on the individual antecedents that form individual commitment, consisting of antecedents such as communication, similarity, interaction frequency and the seller’s expertise. Similarly, it determines the buyer’s commitment to the organisation which consists of antecedents such as dependence on seller, relationship age and relationship benefits.The findings offer important insight of relationships between buyers and sellers in the B2B markets. The results indicate that relationship quality can be increased by simultaneously focussing on individual and organisational antecedents. The individual antecedents that significantly influence relationships in the Life Science industry are the seller’s expertise followed by interaction frequency. Similarly, the organisational antecedents are the relationship age followed by relationship benefits. Overall, the age of the relationship followed by seller’s expertise, interaction frequency and relationship benefits are the most effective relationship-building strategies across all elements of a relationship within this particular industry.This research provides both an academic contribution to the relationship marketing field as well as a practical implication for managers and executives within organisations. The main contribution for academic purposes involves both confirmation and distinctions from hypothesised relationships. The dissimilarities found in this study speak to the importance of the industry setting in which these relationships exits. Furthermore, this study suggests the integration of two bodies of literature: individual and organisational commitment. This research is of specific value to managers who are responsible for increasing relationship capital within their organisations. Simultaneous focus on these antecedents will allow managers to improve their relationship quality with the customer which would assist in retaining the customer on a long-term basis. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

Lead is a toxic heavy metal associated with adverse health effects ranging from developmental neurotoxicity to reproductive effects. While lead affects people of all ages, infants and children are the most vulnerable and susceptible to the neuro-developmental effects of lead exposure. Maternal blood lead concentrations that do not produce clinical toxicity on pregnant women have been linked to adverse offspring development. Observed reproductive effects to low lead levels during pregnancy include the risk of spontaneous abortions, effects on birth weight and preterm birth. There are particular concerns with regard to reductions in IQ scores. Research evidence suggests that an incremental increase in blood lead levels of 1 µg/dL is associated with approximately 1 IQ point deficit. Of particular concern is that currently no threshold has been observed or exists for developmental neurotoxicity to the chronic low lead exposures levels. While the developed countries have built evidence for lead exposure sources, have identified the most vulnerable groups to lead exposure, and have instituted control actions for lead exposure, it is not the case in developing countries such as Botswana. Currently, there is very little knowledge about the potential sources of lead exposure among different population groups not only in Botswana but also in most developing nations. There is also an evident limited knowledge on the behaviours and practices of different population groups that could potentially expose them to lead in developing countries. This thesis explores the following questions: i) Are there specific risk behaviours and practices peculiar to pregnant women in Botswana that could potentially expose them to lead? ii) What are the environmental lead concentration levels and their potential to expose pregnant women? iii)What are the blood lead concentrations at each stage of pregnancy and after delivery in Botswana and, iv) Can we use the information from these three questions to predict lead exposure levels during pregnancy and after delivery? v) Can we use the new information to a develop a policy dissemination brief to inform policy on lead exposure sources in Botswana, develop guidelines for health professionals for assessing and screening lead exposure levels during pregnancy and after delivery, develop an awareness leaflet for lead education? To address the specific risk behaviour and practices of pregnant women, a comprehensive validated risk assessment questionnaire was administered among 142 pregnant women during the first trimester of pregnancy (defined as 8-12 weeks) in four villages of different geographical settings and nomenclature (small/rural, major and semi urban). For purposes of this work the validation process involved obtaining information (from experts in the field and communities) relevant to the purposes of the study and to confirm that the tools employed for collection of data in all trimesters were suitable in terms of both construct and content. Data was collected between September 2009 and February 2010. To address potential environmental sources of lead exposure during pregnancy soil (n=28), water (n=28) and traditional cosmetic clay - letsoku (n=3) samples were collected in November 2010, February 2011 and May 2011 from the homes and in the vicinity of the study population to determine lead concentrations. To know baseline blood lead levels at each stage of pregnancy, blood samples were collected from September 2009 to February 2011 from pregnant women between weeks 8-12 (first trimester, n=137), 20-24 (second trimester n=126) and weeks 34-36 (third trimester n=106). Blood lead levels of women who completed the entire study from trimester on until after delivery (n=63) were then used to construct blood lead prediction models using statistical models. Pregnant women in the study area ingested non-food items such as soil, match sticks, pencil, chalk and animal feed such as bone meal (86%). Women applied used and unused car oils (in particular brake fluid) and other harmful substances for “treatment of skin conditions and for beautification purposes (74%). Older women (defined as 35 years in this study) were at a significantly higher risk to ingest soils (p<0.01). Mean (±SEM) lead concentrations in water exceeded the WHO drinking water quality standards nineteen fold (0.19±0.019 ppm (n=28) Major villages, had significantly higher Pb concentrations (p<0.05) in soils and water compared to small villages. Mean blood lead levels (±SEM) for the first, second and third trimesters were 1.96(±0.14)µg/dL, 2.49(±0.17) µg/dL, 2.66(±0.19) µg/dL respectively. Blood lead levels increases from the first to third trimester ranged from 1.6-5%. Blood lead concentrations significantly differed among locations (p<0.01). The highest concentrations were observed in women from smaller villages that were poorer (p<0.02). Pica, multiple risk behaviours/practices (engaging in two or more risk behaviours/practices), trimester of pregnancy, poor food supplementation and diet were predictors of blood lead levels ≥ 2µg/dL. There was a dose response relationship between supplement intake and an increase in blood lead levels. These findings suggest that pregnant women and their unborn babies could potentially be exposed to lead because of the environment in which they live, their economic status, lifestyle, behaviors and practices. Drinking water is a potential threat for lead exposure, not only among pregnant women, but other vulnerable groups such as infants and children. This study is the first in Botswana and one of the few in Africa to investigate lead exposure sources at each stage of pregnancy and after delivery. It is also the first to identify new potential lead exposure behaviors and practices such as the application of auto oils by pregnant women for treatment of skin diseases. The findings suggest the need to train health workers and equip them with the skills and knowledge to assess and screen women who could potentially be exposed to lead. Further, pregnant women need to be sensitized on potential lead exposure sources, to prevent lead poisoning. This study has been able to use the results to develop a policy brief for disseminating the results to decision makers, guidelines for utilization by health workers to screen lead exposure levels and an awareness leaflet for pregnant women. These have been validated and pretested at community and Government levels. / Thesis (PhD)--University of Pretoria, 2013. / School of Health Systems and Public Health (SHSPH) / Unrestricted

This study investigated the impact of the levels of liquidity of Initial Public Offering (IPO) stocks on the long-run performance of IPOs over a five year period. In addition the study sought to investigate if the levels of liquidity of IPO stock were significantly higher than non-IPO stock. The methodology used was the calendar time portfolio approach based on the Fama-French regression equation. The study found that over a five year period IPOs did not underperform or over-perform the market. In addition the study found that the liquidity levels of IPOs were not significantly higher than non-IPOs. While the lower liquidity levels help explain the fact that the IPOs did not underperform the market, they do not indicate the existence of a liquidity risk premium on the Johannesburg Stock Exchange (JSE). / Dissertation (MBA)--University of Pretoria, 2011. / Gordon Institute of Business Science (GIBS) / unrestricted

This paper provides a history of the standardized testing and accountability movement, the curriculum standards attached to the accountability movement, and the attempted shift to common core. Student poverty and its impact on student achievement the focus of this paper. Recognizing the impact of poverty on student achievement as measured by standardized tests the authors question the explicit practices of teacher preparation programs in preparing teacher candidates to work with students of poverty.

The glycaemic index (GI) is a measurement used to classify foods according to their potential for raising blood glucose levels. The GI of a foodstuff is generally measured by determining the increment in blood glucose concentration after the consumption of a test meal over a set period of time and comparing it with an isoglucosidic control meal (normally white bread or glucose) and expressed as a percentage within a group of individuals (in vivo). Rapid analysis methods (in vitro) are being developed and evaluated worldwide, and in many cases the values obtained have correlated well with the GI values determined by in vivo methods. The criticism against rapid analysis methods is that the methods do not provide numerical GI values. Proposed labelling legislation in South Africa recommends that suppliers should only indicate if the product has a high, intermediate or low GI. The purpose of this study was to investigate existing rapid assessment methods for the prediction of GI, and develop such a method for South Africa to be used by food producers as a screening tool during product development in line with the newly proposed national labelling requirements. The preliminary studies on the developed rapid assessment method indicated good repeatability (CV 0.78%), reproducibility and precision (CV 3.5%). Further comparative trials indicated that the in vitro method accurately predicts the GI category of Almera potatoes (Solanum Tuberosum L. cultivar Almera) and Gero fat free litchi and raspberry flavoured yoghurt, in line with results found from in vivo analysis. Significant inter-laboratory variability of in vivo analysis of GI values obtained for the Almera potato cultivar was found, and the need for future alignment of methodology and sample preparation is recommended./p> / Dissertation (MSc)--University of Pretoria, 2010. / Food Science / unrestricted