THESIS SUBMITED IN FULFILMENT OF THE REQUIREMENT FOR THE AWARD OF THE DEGREE OF DOCTOR OF TECHNOLOGY OF BIOMEDICAL TECHNOLOGTY IN THE FACULTY OF HEALTH AND WELLNESS SCIENCES AT THE CAPE PENINSULA UNIVERSITY OF TECHNOLOGY SUPERVISORS: PROF T.E. MATSHA PROF R.T. ERASMUS DR A. ZEMLIN SUBMITED DECEMBER 2013 / Introduction: Cardiovascular diseases (CVD) have become the leading cause of morbidity and mortality amongst the global population. Originally thought to be a health burden of high income countries, the prevalence is rapidly increasing in developing countries. For example, in 2008, an estimated 17.3 million died from CVD, and 80% of these (13.8 mil) were from low to middle income countries. Epidemiological data on CVD in Africa is scanty and of poor quality and national vital registration is available in only 5% of Africa’s 53 countries. Furthermore, data on CVD risk amongst the South African population and specifically the mixed ancestry community is poorly described. The increasing global population of people with CVD has been largely attributed to increasing rates of determinants and risk factors which include obesity, metabolic syndrome (MetS), type 2 diabetes mellitus (DM) and chronic kidney diseases (CKD). The prevalence of DM in South Africa is known to be on the rise with more affected communities being South African Asians followed by coloureds. Aims and objectives: The aim of this study was to determine the CVD risk profile of the Bellville South community during a baseline and three year follow-up study, by assessment of known risk factors, MetS, type 2 DM, obesity and CKD. Methods: Participants for this study were drawn from an urban community of the Bellville South suburb of Cape Town. At baseline (January 2008 and March 2009) 946 individuals aged 16 to 95 participated. All participants received a standardized interview and physical examination during which anthropometric measurements were performed three times and their average used for analysis: weight (kg), height (cm), waist (cm) and hip (cm) circumferences. Body Mass Index (BMI) was calculated as weight per square metre (kg/m2). A blood sample was obtained from all participants after an overnight fast for the determination of biochemical profiles: glucose, glycated haemoglobin, creatinine, total cholesterol, high density lipoprotein cholesterol (HDL-C), triglycerides and low density lipoprotein cholesterol (LDL-C) which was calculated using Friedewald’s formula. Kidney function test was assessed through estimated glomerular filtration rate (eGFR) using the cockcroft-Gault and MDRD equations. Blood pressure was measured according to the World Health Organisation (WHO) guidelines. Participants with no history of doctor diagnosed DM underwent a 75 g oral glucose tolerance test as recommended by the WHO. Metabolic syndrome was determined using JIS, NCEP ATPIII and IDF criteria. The follow-up examination was conducted in 2011 (3 years from vii baseline) using similar procedures. A total of 198 participants formed the follow-up cohort whose measurements were compared to those of the baseline. Finally, the prediction and processes/progression of the risk factors were determined. Results: At both baseline and follow-up studies, females had a higher BMI compared to their male counterparts. The crude prevalence of type 2 DM, including the previously diagnosed type 2 DM was 28.59% (age-adjusted = 33.5%, 95%CI: 30.01 – 36.92), and that of undiagnosed type 2 DM was 17.8% (age-adjusted = 12.4%, 95%CI: 9.8 – 14.8). The overall prevalence of CKD was 28.7% (269) and was higher in females (31.4%) compared to 20.2% in males. MetS was present in 46.5% of the participants. Gender-specific prediction for CVD risk calculated using the 30-year CVD interactive risk calculator showed that high CVD risk was present in normoglycaemic and younger subjects (under 35 years). At follow-up, the cumulative incidence of progression in glucose tolerance status was: 16.2% (32 participants including 11 with new-onset diabetes), and increased in a stepwise fashion with the number of components of MetS. Between baseline and 3-year evaluation glomerular filtration rate (eGFR) increased by 8.7 ml/min (95% confidence interval: 6.9-10.7), reflecting variables trajectories across baseline strata of kidney functions. Conclusion: Given the findings of this study and the estimated increases in the determinants and risk factors of CVD in the mixed ancestry population of South Africa this trend may continue to worsen if current trajectories do not change.

Thesis submitted in fulfilment of the requirement for the degree Doctor of Technologiae (Biomedical Technology) in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology Supervisor: Prof J van Rooyen Co-supervisor: Prof JL Marnewick Bellville October 2013 / Cardiovascular disease (CVD) is without a doubt one of the most challenging health issues of our time and accounts for the highest number of deaths in both developed and developing countries. Despite the huge strides that have been achieved in the diagnosis and therapeutic intervention of CVD, the disease burden still remains enormous. Therefore, this calls for novel and innovative interventions to curb the surge of CVD. The use of plant based food with bioactive phytochemicals,has a great potential to reduce the incidence of CVD, specifically in resource-strained countries. Red palm oil (RPO) and the indigenous herbal tea, rooibos have previously been shown to exhibit potential cardioprotective effects. Their health promoting properties have largely been attributed to their antioxidant and anti-inflammatory activities and emerging evidence also showed that they have the potential to modulate cell signalling events. Substancial scientific evidence proposes oxidative stress and inflammation to play an important role in the pathogenesis of cardiovascular disease. Hence, natural plant extracts such as RPO and rooibos could be recommended as adjuvants to clinical therapy to reduce the morbidity and mortality associated with CVD. This thesis reports on three studies investigating the cardiovascular protective effects that chronic feeding of either RPO, rooibos or their combination have on 1) antioxidant enzymes and the NO-cGMP pathway in myocardial tissue of spontaneous hypertensive rats, 2) the modulation of systemic and myocardial inflammation and 3) the myocardial ischaemic/reperfusion tolerance in a rat model of lypopolysaccharide induced inflammation. The aim of the first study was to investigate the effect of RPO on cardiac function in sponteneously hypertensive rats. The role of the nitric oxide cyclic-guanosine monophosphate(NO-cGMP) pathway, (as determined by the nitric oxide (NOS) activity) and the antioxidant defence system (selected antioxidant enzymes) were also investigated. Cardiac function was monitored at stabilization and reperfusion using the Langendorff perfusion system. Antioxidant enzymes were determined from left ventricular tissue, while total NOS activity was determined in the aorta and left ventricular tissue. The results show that RPO offered cardiac protection as evidenced by improved left ventricular developed pressure (LVDevP), maximum velocity of pressure rise (+dp/dt) max and fall (-dp/dt) max during reperfusion in sponteneously hypertensive rats (SHR) compared to their control counterparts. Improved function in SHR was associated with increased myocardial superoxide dismutase 2 (SOD2) protein expression compared to the normotensive rats. There was differential modulation of the NOS activity by RPO, an increase in NOS activity was observed in the aorta while a reduction in the activity of NOS was observed in the left ventricular tissue of both RPO supplemented normotensive and hypertensive rats compared to their respective control groups. These results argue a role for elevated NO production in the aorta for endothelial function maintenance. Increased SOD2 protein might lead to reduced oxidative stress. Thus, NO-cGMP pathway and antioxidant defense systems synergistically acted to restore cardiovascular function in SHR. The aim of the second study was to investigate the effect of RPO and rooibos supplementation on the modulation of systemic and myocardial inflammation in a rat model. As RPO and rooibos contain different types of antioxidants which reside and exert their biological effects in different cellular compartments, the combination of these two natural food compounds has the potential to enhance the spectrum of available dietary antioxidants in different cellular compartments, which could result in a better protection against certain pathological conditions such as inflammation. The Langendorff system and the lypopolysaccharide (LPS)-induced inflammatory model were used to determine if RPO and rooibos could protect against the negative effect of LPS-induced inflammation on baseline cardiac function. Both inflammation and dietary supplementation did not have any effect on baseline cardiac functional parameters. Our results show that administration of LPS resulted in elevated plasma levels of IL-1β in supplemented and non-supplemented rats indicating that an inflammatory response was triggered in the LPS-treated rats. However, this increase in IL-1β was counteracted by concurrent elevation of plasma IL-10 in LPS-induced rats consuming either rooibos or RPO alone. Furthermore the combination of RPO and rooibos enhanced myocardial IL-10 levels in LPS-induced rats. This data shows a difference in response to LPS injection between the myocardium and the systemic circulation. The results indicate that the combination of these two natural food substances exhibit potential anti-inflammatory properties which could be beneficial in clinically relevant conditions where inflammation plays a role. Having shown that dietary intervention with RPO and rooibos had the potential to modulate the inflammatory response in the model of inflammation at basal conditions, we then proceeded to the third study to specifically establish if dietary RPO when supplemented alone will improve functional recovery and reduce infarct size in LPS-treated hearts. The Langendorff perfusion system was employed for determination of cardiac function and infarct size. The roles of NFkB, p38 MAPK and the myocardial antioxidant defence systems were investigated as potential mechanisms of protection. LPS-treatment caused significant increases in myocardial IL-1 β indicating that inflammation was induced. However, the levels of myocardial IL-10 was reduced in LPS-treated hearts compared to the non-treated hearts. Intervention with dietary RPO resulted in improved functional recovery and reduced infarct size, in both healthy hearts and in the LPS-treatment group. The RPO-induced cardio-protection was associated with increases in myocardial protein expression of the antioxidant enzymes, SOD1, SOD2, GPX1 as well as increased p38 phosphorylation during reperfusion. LPS treatment increased myocardial protein expression of NFkB p65 which was reversed by RPO supplementation. Reduction of myocardial NFkB protein expression, increased p38 phosphorylation and elevated mitochondrial antioxidant (SOD2 and GPX1) as well as cytosolic enzymes (SOD 1) are proposed as potential mechanisms underlying the RPO-induced cardio-protection in this model. Based on these study results, for the first time, having included vasculature aspects in the cardio-protective effects of RPO we have shown that the NO-cGMP pathway and antioxidant defense systems may act synergistically to restore cardiovascular function in spontaneously hypertensive rats. Results from the second study also provide the first scientific evidence that RPO in combination with rooibos (a flavonoid rich endemic herbal tea) could have potential anti-inflammatory activities at systemic as well as myocardial level, which may be beneficial in clinically relevant conditions where inflammation plays a role. From the third study it can be concluded that dietary RPO improved myocardial tolerance to ischaemia-reperfusion injury in a model of inflammation.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Diagnostic Radiography, Department of Nursing and Radiography in the Faculty of Health Wellness Sciences at Cape Peninsula University of Technology 2014 / Aim: The aim of this study was to record the values of CTDIw and DLP displayed on the Computed Tomography (CT) scanner monitors of patients undergoing CT examinations of the head as Diagnostic Reference Levels (DRL) for dose optimisation in Northern Nigeria. Background: A brain CT scan is the most common CT examination performed, and this modality is recognized as delivering a high dose. CT, therefore, contributes significantly to the total collective effective dose to the population. Elimination of unnecessary or unproductive radiation exposure is necessary. To achieve this, practitioners must adhere to the principles of the justification of practices, and optimisation of radiation protection. Furthermore, the development of DRLs for the local context is advised. These reference doses are a guide to the expected exposure dose from a procedure and are useful as an investigation tool to identify incidences where patient doses are unusually high. Methodology: The study was conducted in three radiology departments with CT centres in Northern Nigeria. Data was collected, using a purposive sampling technique, from 60 consenting adult participants (weighing 70 ±3 kg) that had brain CT scans on seventh generations 4&16-slice GE and 16-slice Philips CT scanners. Prior to commencement of the study the CT scanners were certified by the medical physicists. For each brain scan, patient information, exposure factors, weighted computed tomography dose index (CTDIw), volume computed tomography dose index (CTDIvol) and dose length product (DLP) values were recorded. The data were analysed using SPSS version (16) statistical software. The mean, standard deviation and third quartile values of the CTDIw and DLP were calculated. An inter-comparison of the measured doses from the three research sites was conducted. A combined dose for the three centres was calculated, and compared with the reported data from the international communities where there are established DRLs. Results: The mean CTDIw and DLP values were: centre A (88 mGy and 713 mGy.cm), centre B (68 mGy and 1098 mGy.cm), and centre C (70 mGy and 59 mGy.cm). Comparison of CTDIw and DLP for the scanners of the same manufacturers showed statistically significant differences (p=0.003) and (p=0.03) respectively. In the case of the scanners of a different model but the same number of slices, the comparison of DLP was statistically significant (p=0.005) while no significant difference was noted in the measured CTDIw. Third quartile values of the cumulative doses of CTDIw and DLP, for Northern Nigeria were determined as 77 mGy and 985 mGy.cm respectively. Conclusion: The study has established Local DRLs (LDRLs) which are significantly higher than most of the reported data in the literature. Also dose variation between centres was noted. Optimization is thus recommended. Keywords: Head Imaging, Radiation Dose, Dose optimization, Computed Tomography, Local Diagnostic Reference Levels, Radiation Protection

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Radiography in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology Supervisor: Ms. Ferial Isaacs Co-supervisor: Prof. Susan J. Van Rensburg Bellville September 2013 / Multiple Sclerosis (MS) is characterised by demyelination within the central nervous system (CNS), which may result in neurological disabilities over time, causing considerable hardship to patients and their families, in addition to being costly to treat. Recent studies have linked MS to impaired cerebral blood flow, called chronic cerebrospinal venous insufficiency (CCSVI). Anecdotal evidence has suggested that surgical correction thereof results in improvement of symptoms experienced by MS patients. To my knowledge, no information is available in the literature on carotid artery disease in MS. The USA National MS Society has therefore called for more research to be done in this area. This cross-sectional observational sub-study will determine, by ultrasound (B-Mode, Colour and Pulsed-wave Doppler), the prevalence of chronic venous insufficiency (CCSVI) and carotid artery disease in the selected sample of MS patients within the region of the Western Cape, South Africa. Biochemical data; lifestyle factors such as physical activity and smoking; and nutritional status of MS patients were determined from the main study entitled: “The development of a comprehensive gene-based, pathology supported intervention program for improved quality of life in patients diagnosed with multiple sclerosis” (Division of Chemical Pathology, NHLS, Tygerberg Hospital, and University of Stellenbosch). Twenty-nine (29) patients were aged between 28-64years and they suffered from MS for 0.83-27years. A larger proximal and mid cross-sectional diameter (CSD) of the right IJV compared to the left (differences significant, P= 0.026 and P=0.023) was demonstrated. Increased intima media thickness (IMT) was present in 13.33% of the non-smoking MS group and 20% in the smoking MS group. IJV reflux was evident in 13.33% of the MS group. A significant reduction of cross-sectional diameters of the IJV’s was evident in smoking MS patients; suggesting that smoking is not only a risk factor for atherosclerotic disease but could also be related to narrowing of the major neck veins. This study also supports findings of other studies viz that there’s no significant correlation between extracranial venous abnormalities and MS. Early carotid artery disease was noted in smoking and non-smoking MS patients, however the findings were non-significant.

Thesis submitted in fulfillment of the requirements for the degree Master of Technology:Electrical Engineering in the Faculty ofEngineering at the Cape Peninsula University of Technology Supervisor:Prof MTE KAHN Bellville December 2013 / The work presented in this thesis consists of the simulation of a cooling plant for a future mobile satellite ground station in order to minimize the effects of the thermal noise and to maintain comfort temperatures onboard the same station. Thermal problems encountered in mobile satellite ground stations are a source of poor quality signals and also of the premature destruction of the front end microwave amplifiers. In addition, they cause extreme discomfort to the mission operators aboard the mobile station especially in hot seasons. The main concerns of effective satellite system are the quality of the received signal and the lifespan of the front end low noise amplifier (LNA). Although the quality of the signal is affected by different sources of noise observed at various stages of a telecommunication system, thermal noise resulting from thermal agitation of electrons generated within the LNA is the predominant type. This thermal noise is the one that affects the sensitivity of the LNA and can lead to its destruction. Research indicated that this thermal noise can be minimized by using a suitable cooling system. A moveable truck was proposed as the equipment vehicle for a mobile ground station. In the process of the cooling system development, a detailed quantitative study on the effects of thermal noise on the LNA was conducted. To cool the LNA and the truck, a 2 kW solar electric vapor compression system was found the best for its compliance to the IEA standards: clean, human and environment friendly. The principal difficulty in the development of the cooling system was to design a photovoltaic topology that would ensure the solar panels were always exposed to the sun, regardless the situation of the truck. Simulation result suggested that a 3.3 kW three sided pyramid photovoltaic topology would be the most effective to supply the power to the cooling system. A battery system rated 48 V, 41.6 Ah was suggested to be charged by the PV system and then supply the power to the vapor compression system. The project was a success as the objective of this project has been met and the research questions were answered.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: in Information Technology in the Faculty of Informatics and Design at the Cape Peninsula University of Technology Supervisor: Dr Ephias Ruhode Cape Town campus December 2013 / The use of ICTs such as computers, electronic databases and other technologies have been in use for a number of years within the public sector to organise, manage and disseminate information to the public as well as to facilitate day-to-day communication in government offices. In this context, the value of the use of ICTs has been to assist and streamline government operations. The technological development in South Africa has opened up the possibilities of the use of ICTs in the democratic and governance process. E-democracy has been defined as a tool for abandoning the representative system for one with more direct citizen engagement. This study sets out to explore the challenges of the current electoral process, and also determine the factors that could influence the adoption and diffusion of e-voting technologies within the South African context. Literature has shown that countries such as Brazil and India have successfully implemented electronic voting systems and other countries are at various piloting stages to address many challenges and problems associated with manual paper based system such as costs of physical ballot paper and other overheads, electoral delays, distribution of electoral materials, and general lack of confidence in the electoral process. It is in this context that the study also seeks to determine whether the South African electoral management body can leverage on the opportunities that e-voting presents. However, with all the benefits that e-voting presents, there are countries such Germany, the Netherlands etc. that have tried and tested e-voting systems and decided to abandon these system to go back to the manual paper ballot voting systems because of various reasons ranging from cost, security and verifiability. This research is exploratory in nature and adopts qualitative research approach and it is within the interpretivism paradigm. Survey and interview strategies were used to collect data. A purposive sampling method was used to select the participants for the survey. To gain an understanding of the views of voters and electoral management body (IEC) about the current electoral process and e-voting technologies, literature was explored, a questionnaire was distributed online to voters and an in-depth semi-structured interview was conducted with the IEC. The study targeted voters who had access to the internet since the survey questionnaire was distributed online. The analysis is based on thematic analysis and diffusion of innovation (DoI) theory was also used to provide an analytical framework for the study. Through this framework the aims and objectives of the study were conceptualized around three constructs from the theory (relative advantage, compatibility and complexity). The findings of the study revealed that the three constructs from the DoI framework are important factors that may influence the adoption process of e-voting technologies. The findings also revealed other factors such as availability of ICT enable infrastructure and resources, digital divide, trust in technology, awareness of the technology and environment could that also influence the adoption process. The contributions of this research are anticipated to be a better understanding of the adoption of e-voting technologies in South Africa. For the electoral management bodies, the contribution of this research is that the research to some extent portrays factors that could influence the adoption of e-voting technologies in South Africa. Therefore, findings such as availability of ICT infrastructure and accessibility of these infrastructures should be taken into consideration before introducing e-voting technologies. Keywords: DoI (diffusion of Innovation), e-voting (electronic voting) technologies, E-governance, e-participation.