A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in the field of Medical Physics. 2017 / Aim The aim of this research was to contribute to clinical implementation of the small field dosimetry Code of Practice (CoP) that is due to be published by the International Atomic Energy Agency (IAEA) in collaboration with the American Association of Physicists in Medicine (AAPM) (1). A 6 cm × 6 cm virtual machine-specific reference (fmsr) field was established in a clinical 60Cobalt teletherapy beam used for conventional radiotherapy at Charlotte Maxeke Johannesburg Academic Hospital, and relative output factors were measured down to a set field size of 1 cm × 1 cm using three different models of Physikalisch-Technische Werkstatten (PTW) small field ionization chambers. Materials and Methodology The measurements were all performed on a Cobalt teletherapy unit (MDS Nordion Equinox, S/N 2009) in a PTW MP3 water phantom. The small field ionization chambers that were used were a PTW 31016 3D pinpoint 0.016 cm3, a PTW 31006 pinpoint 0.015 cm3 and a PTW 31010 semiflex 0.125 cm3. A calibrated PTW 30013 Farmer 0.6 cm3 ionization chamber was used to provide traceability for the cross calibration. A ―daisy chain‖ methodology was used to perform the cross calibration in a virtual fmsr field of 6 cm × 6 cm and then establish the absolute dose rate in a 4 cm × 4 cm field. Relative output factors as a function of field size were measured with each small field ionization chamber and then compared to published results. Results Small square fields from a 60Cobalt beam were created using the secondary collimators integrated into the unit. Equivalent square fields were calculated using the profiles obtained by the three ionization chambers during scanning and were in agreement with the ones that were programmed into the console. The coincidence of the central axis of the beam and the point of measurement for each detector was determined from the beam profiles. The cross calibration and daisy chain measurements resulted in a consistent dose rate of within + 0.6% in the 4 cm × 4 cm field when measured with the four different ionization chambers. For 6 cm × 6 cm, 4 cm × 4 cm, 3 cm × 3 cm and 2 cm × 2 cm field sizes, relative output factors obtained from the uncorrected detectors’ response agreed to within + 0.8 % between the three small field ionization chambers. The variation in the 1 cm × 1 cm field size was + 8.1 %. When compared to published data, large differences in field size correction factors were obtained. Conclusion Small field dosimetry in a 60Cobalt photon beam using three different PTW small field ionization chamber models was investigated. A cross calibration in a virtual msr field was done followed by a daisy chain process to determine the dose rate in a small field. Dose profiles and relative output factors were then measured and compared. The lack of lateral charge particle equilibrium and volume averaging effect was evident when using the PTW 31010 semiflex chamber in a 1 cm × 1 cm field. The PTW 31006 pinpoint and 31016 3D pinpoint were in close agreement for field sizes down to 1 cm × 1 cm with the 3D pinpoint performing as the best detector in this study. The optimal positioning of a detector should be determined from beam profile scans and not the engineering diagrams. The PTW 31016 3D pinpoint and PTW 31006 pinpoint are recommended for the determination of output factors in small field sizes. However, field output correction factors are required for both detectors in field sizes under 2 cm × 2 cm. Small field data published in the British Journal of Radiology (BJR) Supplement 25 (2) should not be used to benchmark dosimetry in modern 60Cobalt teletherapy units. / MT 2017

Thesis (Ph. D.)--University of Wisconsin--Madison, 1972. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Magister Curationis - MCur / Academic hospitals do recognise that all patients have basic human needs. Nurses have been obliged to pay attention to conditions that destabilise patient's health. An academic hospital in the Western Cape is dedicated to living up to its vision to deliver excellent nursing services, which include the fulfilment of the basic needs of patients who are making use of surgical emergency department. Emergency surgical departments should be created in a manner that provides safety and comfort to patients. Patient satisfaction is influenced by the manner in which their expectations about the successful addressing of their basic needs are met. At the moment, the extent of meeting these basic needs during the delivery of nursing care in the surgical emergency department of the academic hospital is unclear. The purpose of this study was to explore and describe the perceptions of patients about the fulfilment of their basic needs during nursing care in a surgical emergency department at an academic hospital in the Western Cape. The study was conducted according to a quantitative non-experimental descriptive survey design. A convenience sampling method was used to select patients (n = 150) after they were discharged from a surgical emergency department. A self-administered questionnaire was compiled within the framework of Alderfer's theory, with closed and a few open questions, that was for distribution to respondents. Descriptive statistics were extracted. The responses to items were indicated on a continuum starting at 1 (never) to 7 (always) on a 5-point Likert scale. Respondents signed informed consent before they completed the instrument in a private room that took around 30 minutes. In this study, validity and reliability were maintained during the research process, and ethical principles were adhered to. Descriptive data was presented through mean values and standard deviations and a factor analysis performed. The findings were presented according to six factors that indicated that the responses varied on the basic existence, relatedness and growth needs of patients in a surgical emergency unit. From the findings, recommendation was described for the operational nursing managers in the surgical emergency department to take action during addressing patients' basic needs in the delivery of nursing care. It can be concluded that patients perceive that many of their basic needs are not being met while receiving surgical emergency care.

The research used a change management approach to analyze the restructuring of the Nelson Mandela Academic Hospital from a tertiary to a central hospital. The study was underpinned by two objectives. Firstly, to analyze the restructuring of the Nelson Mandela Academic Hospital from a tertiary to a "central" hospital using the Core Elements Framework of change management developed by Antwi and Kale (2014). Secondly, to use the knowledge gained through literature review combined with the experiences of the managers at Nelson Mandela Academic Hospital to inform future healthcare reforms in general and particularly in the restructuring of hospitals. The Core Elements Framework by Antwi and Kale (2014) identifies six fundamental change elements from both emergent and planned change management approaches. The six elements are regarded by theorists from the two different schools of thought i.e. emergent change and planned change as key for successful change. The Core Elements Framework by Antwi and Kale, (2014) demonstrates the strength of not viewing the two approaches to change management as mutually exclusive but as complementing each other when the other is falling short. The study identified the following: ■ The change was prompted by clearly identifiable external factors more than internal factors. ■ There was notable lack of organizational harmony which may have negatively impacted the change process. ■ The Private Public Partnership (PPP) funding model which was aimed at delivering the central hospital collapsed, after a study discovered that it benefited the private sector more than the public sector. ■ There was no proper consultation of major stakeholders for preparation of the change. ■ Resources in all material forms were not made available for the change to take off, this means that there was no organizational capacity to execute the change. The study draws the conclusion that lack of organizational capacity, organizational harmony and a proper consultation process for stakeholders are the main reasons why the restructuring of the Nelson Mandela Academic Hospital is not yielding the desired results. The study recommends that organizations should implement a multidimensional approach for any change initiative to be successful and that organizations must ensure the availability of the necessary resources when embarking on change.

Magister Curationis - MCur / Community service has been an inevitable part of most health professionals’ lives since it began in 1998. In 2004 the Health Minister in South Africa announced that community service will be extended to include nurses once the Nursing Bill of 2005 was passed by Parliament. Community service for nurses is one year of service after graduation and before the graduate is registered as a professional nurse with the South African Nursing Council. The period of transition from student to newly qualified nurse is known to be stressful. “Reality shock” is a common experience for newly qualified nurses who find themselves in work situations for which they feel inadequately prepared. The aim of the study was to explore the professional nurses’ experience of the community service year at a secondary hospital in the Western Cape. The two objectives were to explore the professional nurses’ experience of their transition from student to community service practitioner and to explore the support and challenges experienced by professional nurses during their community service year at a secondary hospital in the Western Cape. A qualitative research approach and an exploratory and descriptive research design were used to gain insight into the professional nurses’ experiences of their community service year. The population included all professional nurses employed in community service during 2012-2013 and who were working at the selected research site, a secondary academic hospital in the Western Cape. Participants, sampled through purposive sampling, participated in semi-structured interviews during September 2014-January 2015. The inductive process described by Thomas (2003) was used to analyse the data. The results of this study revealed that the community service year was experienced as difficult as it required the community service practitioners to apply new knowledge and take on a higher level of responsibility in practice. The undergraduate nursing programme was perceived as not preparing them for the responsibility as community service practitioner.However, transition from student to community service practitioner was experienced as positive as they developed positive relationships with staff that supported them through the process while they developed professionally.

Magister Curationis - MCur / In South Africa, the Occupational Specific Dispensation (OSD) for professional nurses provides a structure for training and career progression in the Public Health Sector. It necessitates the urgency for professional nurses who are working in specialty units at hospitals, to study further in advanced post-graduate nursing sciences programmes, e.g. advanced psychiatric nursing. Professional nurses were not informed about the implications of the OSD for practice, prior to implementation. It was unclear how advanced psychiatric nurses were experiencing their practice in an OSD hospital setting. In this study, the experiences of advanced psychiatric nurses who were practising at an OSD psychiatric public hospital led to the description of guidelines for supporting these nurses during their practice in an OSD ward. A qualitative, exploratory, descriptive and contextual design was followed. The study population consisted of advanced psychiatric nurses (N = 50). Purposive sampling was conducted until data saturation was reached. Eight participants were included in the sample. In-depth unstructured individual interviews were conducted with each of these participants. Field notes were kept and voice recordings of all interview sessions were captured. The researcher conducted a pilot study with one participant in order to detect possible flaws that could occur during the data collection process. The data analysis where themes were identified was based on Tesch‟s method of qualitative analysis. A literature control supported the findings of this study. Subsequently, guidelines were described from the findings according to the method of Muller (2001:204-205). Trustworthiness was maintained by using the criteria of Guba‟s model; that is credibility, transferability, confirmability, and dependability. The ethical principles of the right to self-determination, withdrawal from the research study, privacy, autonomy and confidentiality, fair treatment, protection from discomfort and harm, and obtaining informed written consent was adhered to. Four themes emerged from the data that indicated: the under-utilisation of the full scope of advanced nursing skills, role conflict and overload, organisational structural barriers that delayed viii the implementation and practice of advanced nursing skills, and failure to conceptualise / clarify advanced nursing role that resulted in unrealistic and / or unmet expectations.

>Magister Scientiae - MSc / In South Africa, the Occupational Specific Dispensation (OSD) for professional nurses provides a structure for training and career progression in the Public Health Sector. It necessitates the urgency for professional nurses who are working in specialty units at hospitals, to study further in advanced post-graduate nursing sciences programmes, e.g. advanced psychiatric nursing. Professional nurses were not informed about the implications of the OSD for practice, prior to implementation. It was unclear how advanced psychiatric nurses were experiencing their practice in an OSD hospital setting. In this study, the experiences of advanced psychiatric nurses who were practising at an OSD psychiatric public hospital led to the description of guidelines for supporting these nurses during their practice in an OSD ward. A qualitative, exploratory, descriptive and contextual design was followed. The study population consisted of advanced psychiatric nurses (N = 50). Purposive sampling was conducted until data saturation was reached. Eight participants were included in the sample. In-depth unstructured individual interviews were conducted with each of these participants. Field notes were kept and voice recordings of all interview sessions were captured. The researcher conducted a pilot study with one participant in order to detect possible flaws that could occur during the data collection process. The data analysis where themes were identified was based on Tesch‟s method of qualitative analysis. A literature control supported the findings of this study. Subsequently, guidelines were described from the findings according to the method of Muller (2001:204-205). Trustworthiness was maintained by using the criteria of Guba‟s model; that is credibility, transferability, confirmability, and dependability. The ethical principles of the right to self-determination, withdrawal from the research study, privacy, autonomy and confidentiality, fair treatment, protection from discomfort and harm, and obtaining informed written consent was adhered to. Four themes emerged from the data that indicated: the under-utilisation of the full scope of advanced nursing skills, role conflict and overload, organisational structural barriers that delayed the implementation and practice of advanced nursing skills, and failure to conceptualise / clarify advanced nursing role that resulted in unrealistic and / or unmet expectations.

Estimates of left atrial size in patients with suspected cardiac disease play an important role in diagnostic medicine. Left atrial size is used in predicting prognosis and events, as well as treatment decisions. Two methods are commonly used to estimate left atrial size: chest radiography and cardiac ultrasound. This study aims to determine the test characteristics of chest radiography and compare the use of radiographs to cardiac ultrasound (the gold standard test). Data from patients older than 18 years admitted to Pretoria Academic Hospital during 2000-2003 who had both chest X-rays and cardiac ultrasound were included in this cross-sectional, retrospective analysis. Chest X-rays were classified into three quality classes, and the sub-carinal angle (SCA) and sub-angle distance (SAD) were measured twice in all available X-rays by two observers. Intra- and interobserver variability (3 methods) as well as the predictive value of the SCA and SAD measurements were determined using logistic regression (with left atrial size determined by ultrasound as comparator). P-values < 0.05 were regarded as statistically significant for all comparisons. Data for 159 patients were available (154 cardiac ultrasounds and 178 chest radiographs). Intraobserver variability regarding chest X-ray measurements was low with almost perfect concordance (P=0.000). Interobserver variability was higher for supine X-rays. Using logistic regression, a linear model was identified which was statistically significant only for erect X-rays. While goodness-of-fit analysis showed that the model fits the data, performance characteristics were poor, with high sensitivity and low specificity, and an area under the ROC curve of 0.62-0.63, depending on type of X-ray and measurement (SCA or SAD). Linearity in the logit of the dependent variable was assessed, and found to be present at the extremes of carinal angle measurements for the supine X-ray data and in the first three quartiles for erect X-ray data. A non-linear model determined by fractional polynomial analysis did not perform significantly better than the original linear model. Cut-off values for the SCA of 72o and 84o (erect and supine X-rays, respectively) were found to give the best compromise between sensitivity and specificity. The corresponding cut-off values for SAD were 24.1mm and 26.9mm. Assessment of either SCA or SAD to determine left atrial size is equivalent and repeatable, both within the same observer, and between two observers (less so for supine X-rays). While this measure is precise, it was found not to be very accurate. Therefore, chest X-rays are not reliable in predicting left atrial enlargement. / Dissertation (MSc (Clinical Epidemiology))--University of Pretoria, 2007. / Clinical Epidemiology / unrestricted

A dissertation submitted in accordance with the requirements for the degree of Master of Science in the Faculty of Science at theUniversity of Witwatersrand, Johannesburg, 2012. / AIM: This studied aimed at analysing the set-up error (margin) of head and neck cases, treated in a vacuum formed acrylic shell with an in-house immobilisation system. METHODS AND MATERIALS: Two population groups were studied, namely virtual simulated and intensity modulated radiotherapy (IMRT) cases. All cases were treated with the in-house immobilization system, which located centrally, but not longitudinally, to the treatment couch. Verification of the couch position, other than the isocentric angle, was not activated. The virtual simulated cases consisted of two lateral fields with a matched anterior neck field. The borders of these fields were chosen by the radiation oncologist. The IMRT cases were planned by a medical physicist and consisted of 6-9 fields of 3-4 intensity levels each. Digitally reconstructed radiographs (DRRs) of the 2 lateral fields and the anterior neck field for the virtual simulated cases, and the 2 lateral and anterior composite fields at the same isocentre for the IMRT cases, were printed and represented the ideal patient position. On the first day of treatment, megavoltage verification films were taken of the treated or positioning fields respectively. These verification films were compared to the DRRs and approved by a radiation oncologist. The absolute bed position in the vertical (Y), lateral (X) and longitudinal (Z) directions at the time of film approval, was used as the reference or ideal position. The absolute readings of the couch position that were captured daily over the course of treatment were then compared to the initial couch position to give an indication of the systematic and random errors. One linear accelerator was used in this study and weekly mechanical quality control (QC) was performed on it. RESULTS: The total number of daily fractions (F) studied in this thesis was 5644 and 600 for virtual simulated and IMRT cases respectively. The systematic error of this population was 4.7 and 4.4 mm for the virtual simulated and IMRT cases respectively. This compares well with published results using a similar immobilisation system. The random error of this population was 7 mm and 6.1 mm for the virtual simulated and IMRT cases respectively. This is three times larger than the results reported in the literature (using a similar immobilization device). CONCLUSION: Offline monitoring of couch position provides insight into setup margins and this can contribute to realistic institutional planning target volumes. Better results were obtained in the IMRT cases and this could be due to the requirement for weekly verification imaging. Lack of radiation therapist vigilance and insufficient training were most likely responsible for the individual cases with systematic variations of larger than 3 cm. The data confirm that the immobilisation system can be located to a fixed position on the tabletop; this will allow online verification of absolute bed position for treatment and further decrease the chance of incorrect setup.

Background: Canine babesiosis is a tick-borne disease causing detrimental health effects on the domestic dogs with huge economic impact on the owners. The most complicated form of canine babesiosis is caused by a pathogenic Babesia rossi parasite. Canine babesiosis induced by B. rossi still remains the cause of mortality and morbidity in South African dogs, yet, the transcriptomic and genomic information of this parasite species is still not available. The transcriptomic and genomic information is essential in the disease development and processes for the design of effective disease control strategies. Consequently, our understanding of the mechanisms underlying the pathogenesis of the different genotypes of B. rossi remains limited. A previous study suggested a relationship between the parasite genotype and the disease phenotype. To date, thirteen B. rossi genotypes have been identified and associated with diverse clinical signs in their hosts. Hence the aim of this study was to sequence RNA from samples representing B. rossi genotypes, 19, 29 and 31, in order to have insight on the overall transcriptome of this parasite and to establish if there would be significant differences among the genotypes. Methodology: To screen for B. rossi positive samples, total DNA was extracted from 20 blood samples collected from sick domestic dogs presented at the Onderstepoort Veterinary Academic Hospital (OVAH). Babesia rossi infections were confirmed using the PCR-Reverse Line Blot (RLB) hybridization assay. Further confirmation of infection status was done by amplification of the B. rossi Erythrocyte Membrane Antigen 1 (BrEMA1) gene in all the DNA samples using qualitative PCR (qPCR), followed by sequencing of PCR products. Subsequently, total RNA was extracted from the 20 B. rossi-infected blood samples collected from the same dogs in which DNA was extracted. Three samples representing B. rossi genotypes 19, 29 and 31 were selected for transcriptome analysis. RNA sequencing was performed using the Illumina HiSeq 2000 to allow transcriptome analysis. De novo assembly was performed independently for all three transcriptomes using the Trinity software. The unigenes generated from specific transcriptome assemblies were subjected to global functional annotation using Blast2GO version 2.8.0 software, followed by KEGG database for annotation of biological pathways, and DAVID version 6.7, for COG classification to predict and classify their functions. Results: The sample representing B. rossi genotype 31 was excluded in the transcriptome analysis due to low RNA mass, which usually compromises the quality of the library used in RNA sequencing.Thus, a total of 26 747 238 and 25 709 627 paired-end reads were obtained from B. rossi genotypes 19 and 29, respectively. De novo transcriptome assembly produced a total of 3019 unigenes, with an average length of 419 bp and N50 of 362 bp in B. rossi genotype 19, and 2727 unigenes with an average length of 441 bp and N50 of 362 in B. rossi genotype 29. A total of 1193 unigenes were common between B. rossi genotype 19 and 29, while 1828 unigenes were exclusively detected in B. rossi genotype 19; and 1534 were specific to B. rossi genotype 29. Between the two B. rossi genotypes, a total of 4553 unigenes were obtained, representing the overall B. rossi transcriptome. From the overall transcriptome, 12.3% (n=558) of the unigenes could be annotated with 53 different gene ontology (GO) functional categories. About 34% (n=1550) of the unigenes represented in the overall transcriptome mapped to 237 KEGG pathways and only 2.5% (114) could be annotated in the COG database. Conclusion: Although, there were no striking differences in the transcriptomes of B. rossi genotypes 19 and 29, this study presents the first transcriptomic resource for B. rossi, which will highly contribute to our genetic understanding of B. rossi and provide a platform for future gene expression studies. Hypothetical proteins identified in this study will require further characterization as they may have a critical role in the biology and pathogenicity of B. rossi parasite. / Life and Consumer Sciences / M. Sc. (Life Sciences)