Water is essential to all life but many freshwater resources are polluted through human activities. Humans and wildlife are exposed to a wide range of contaminants through their water, many of which pose a risk to health. Some of the contaminants released into the environment have been reported to have the capability to disrupt the endocrine functions in humans and wildlife and they can mimic or antagonise the action of estrogenic. These endocrine disrupting chemicals (EDCs) interact with physiological systems and cause alterations in development, growth and reproduction in wildlife and humans. To achieve some measure of assessing the potential harm that the contaminants pose, we need to know the environmental concentration of the chemical concerned and to monitor their effect on the organisms. The water supply sector need to include EDCs in standard systems of routine water source monitoring which include indicator bacteria and nutrient species but before the system can be incorporated, methods to measure the occurrence of EDCs in aquatic environment need to be developed and validated and a reliable guidelines data need to be in place. The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) to quantify vitellogenin (VTG) in Oreochromis mossambicus (Mozambique tilapia) VTG has been used successfully as a biomarker for estrogenic contamination in different studies. For this study, VTG was isolated and purified from plasma of 17β-estradiol exposed tilapia by gel filtration chromatography. The purity of the VTG isolate was confirmed by polyacrylamide gel electrophoreses (SDS-PAGE). Polyclonal antibodies against t-VTG were raised in rabbits and the specificity of the anti-t-VTG was confirmed by western blot. Using purified t-VTG as a standard and anti-t-VTG antibody, a homologous competitive ELISA was developed and validated. The standard curves of the ELISA, which were generated on different days, were identical which indicate that the assay is reliable, reproducible and repeatable. The intra-assay and inter-assay coefficient variation was 2.41 (n = 4) and 8.71 (n = 10) respectively. The serial dilution of plasma VTG from exposed tilapia showed a good parallelism with the standard t-VTG within the working range of the assay. The serial dilution of the reference fish did not cover the whole range of the t-VTG standard curve. By using the standard curve and the dilution of the exposed plasma, we were able to demonstrate that the ELISA was able to quantify VTG. With good laboratory practise, this ELISA can be use to quantify VTG in chemically exposed fish. It will also be ideal to continue analyzing the antibody to determine the appropriate dilutions necessary to ensure that the assay work its optimal capabilities. / Dr. I. Barnhoorn Prof. P. Jagals Prof. J.H.J. Van Vuren

Corporate social and environmental disclosure, later redefined as sustainability disclosure in order to include the third pillar of sustainability (economic), has been the subject or significant research over the past four decades. A major branch of empirical research has specifically focussed on the determinants of disclosure; those factors which correspond with greater breadth and depth of disclosure. Research has traditionally been focussed on the developed world, specifically North America and Western Europe and either addressed social or environmental disclosure in isolation or various hybrids of the two.This research has two aims. Firstly it is an attempt to provide a view of disclosure in Africa, and specifically South Africa, where only minor empirical research has been undertaken. Secondly and crucially, this research attempts to address shortcomings in the existing body of research in that factors have traditionally been analysed for significance with regards to individual sustainability pillars alone, or at the aggregate level. A content analysis technique was employed to score sustainability reports for social, environmental and economic disclosures. An analytical model was then developed and a number of internal and external factors analysed to establish which were significant determinants of the level or extend of disclosure at both the individual pillar level and then compared to the aggregate or overall disclosure. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

A relatively new method of measuring local velocity in a fluid stream has been devised which eliminates some of the inherent problems of the traditional methods. This method senses the Doppler shift of light scattered from a laser beam incident on particles suspended in the fluid. The Doppler shift is proportional to the particles (or fluid) velocity. This new technique has several distinct advantages over the more traditional methods of velocity measurement.

Sustainability means providing for the necessities of today without endangering the necessities of tomorrow within the technical, environmental, economic, social/cultural, and individual contexts. The assessment tools available to study the sustainability of the built environment are limited in their approach and lacking in their content due to several reasons: (1) differences amongst the actors within the industry; (2) fragmentation as represented by lack of communication and understanding between the industry and those whom it serves; and (3) regionalism as represented by the disconnection between the construction projects and their host community systems. The narrow focus of the currently available assessment methods does not collectively address the technical, environmental, economic, social/cultural, and individual sustainability indicators as well various aspects of sustainability. To this end, this research develops three innovative system-based concepts to assess sustainability of civil infrastructure projects: (1) work, (2) nature, and (3) flow. The “work benchmark” defines the socio-behavioral relationships amongst the products and the actors of the built environment. It also attempts to delineate how the end-product is affected by how well the producers are connected to the product. The “nature benchmark” focuses on the effects of the built process on the environment through studying the interaction between the construction actors, their associated processes, and the end-products within their host systems. The “flow benchmark” identifies the overall system changes within the host systems and the effects of these changes on the natural environment and the socio-economic setting. For testing and evaluation of “nature” and “work” on five different types of civil infrastructure projects, the author utilized a three-step methodology comprising: (1) structured survey; (2) data collection; and (3) analysis. In order to avoid being unrepresentative of the industry, the author chose projects with different scopes representing a wide spectrum of construction projects. This process provided an improved understanding of the environmental, social, and economic effects of these projects from a systems perspective. For future work, the concept of “flow” will be further explored using macro-level system dynamics modeling, micro-level agent-based simulation, and multi-objective optimization to measure the overall system change.

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yes / Identifying and explaining the pathophysiology of sepsis, as well as the importance of monitoring for indicators of patient deterioration in sepsis.

The recent reports by Institute of Medicine, `To Err is Human' and `Crossing Quality Chasm', revealed a large prevalence of medical errors and substandard care in US hospitals. Since then there has been a substantial increase in the efforts to measure and improve quality of care. The objective of this study was to compare the quality of care across hospitals using available performance indicators and examine the association between organizational factors and hospital performance. The main focus of this study was on important structural attributes of hospitals, namely - teaching status, location and market competition. The Nationwide Inpatient Sample for years 2003 and 2005, and the State Inpatient Database for years 2004 to 2006 were used for analyses. Two types of hospital performance indicators were examined to compare quality of care - Patient safety indicators developed by Agency for Healthcare Research and Quality, and process of care indicators developed by Centers for Medicare and Medicaid services. Multivariable regression analyses were performed using generalized estimating equations and random effects regression models. Several organizational factors as well as patient characteristics were included in the multivariable models as control variables. Overall, the results from this study showed an inconsistent relationship between teaching status, location of hospitals or market competition and quality of care in hospitals. In addition, the results demonstrated that isolating potential effects of hospital structure on outcomes requires controlling for the variation in patient characteristics, such as age and comorbidities, which increase patients' risk for incurring patient safety events. The findings from this study provide useful insight into the areas where the patient safety and quality initiatives should be focused. Moreover, the results identified the organizational factors that are relevant to certain types of hospitals and which should be considered before evaluating quality of care and enacting any policies about publicly reporting of performance or payment initiatives that are relevant to these hospitals.

published_or_final_version / Statistics / Master / Master of Social Sciences

A research report submitted to the Faculty of Science, in partial fulfilment of the requirements for the degree of Master of Science, University of the Witwatersrand, Johannesburg. 30 October 2014. / The reporting of non-financial data has steadily increased over the past three decades and there is evidence that including social and environmental indicators in the annual report is correlated with improved environmental performance of listed companies. The annual reports of a selection of 82 JSE-listed companies, including the full JSE Top 40, were analysed for mentions of the natural environment for the reporting periods of 2010 and 2012. The introduction of the King III principles by the JSE occurred between these two periods, providing an opportunity to assess the impacts that this move had on annual reporting. Attention was paid to mentions in the leadership reviews by the Chairmen and the CEOs, presence of empirical environmental data, environmental KPIs and the manner in which these data were presented and discussed in the report. In addition, a survey asking qualitative details of company reporting policy was conducted among the staff members responsible for environmental reporting of these companies. The standard and sophistication of environmental reporting varied widely across the sample, with Top 40 companies generally reporting better than non-Top 40 companies. Primary industries were more likely to provide empirical data than service industries and only agricultural industries appeared concerned with the manner in which changes in the natural environment could affect their business. There remains a wide variation in the type and detail of environmental reporting across the sample with very little evidence that the data, as reported, play a meaningful role in the decisions of either management or investors.