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Trends in clinical presentation and treatment outcomes in a South African TTP cohort
(2024) Vundla, Nokubonga; Verburgh, Estelle; Bailly, Jenique
Background: HIV is the most common cause of secondary thrombotic thrombocytopenic purpura (TTP) in South Africa. Objectives: To assess the clinical presentations and outcomes of patients treated for HIV-associated and idiopathic TTP. Methods: We conducted a retrospective cohort study of patients consecutively diagnosed with TTP from 2010 to 2020 at Groote Schuur Hospital. Study participants were identified by reviewing patient files and Western Cape Blood Services records. Kaplan-Meier curves and log-rank tests were used to evaluate remission rates overall and, by HIV status and treatment group. Logistic regression models were used to identify predictors of remission and relapse. Results: 139 patients were included, 85.6% of whom were HIV positive. There were no significant differences in the TTP pentad features by HIV status. Most patients achieved remission (71.9%) with an overall median time of 8 days. Remission occurred significantly earlier in those treated with FFPs only, suggesting less severe disease (median=8 days [IQR 6-10]), compared to those requiring the addition of plasma exchange suggesting more severe disease (median=12 days [IQR 8-22]). The overall mortality in the 10-year period was 38.9%, with 10.8% of the surviving patients relapsing after a median of 169 days (IQR 146-281) following the initial TTP event. There were no significant differences in remission status, time to remission, mortality or relapse by HIV status. All HIV positive patients who relapsed had defaulted their antiretroviral therapy (ART). Conclusion: HIV status did not affect patient outcomes in our cohort. ART is important in preventing HIV-associated TTP and relapse. What this study adds: A well-defined demographic of patients with TTP in the ART era in South Africa. Key words: Thrombotic thrombocytopenic purpura, haemolytic anaemia, thrombotic microangiopathy, HIV-associated TTP, ADAMTS13, treatment outcomes, plasma infusion, plasma exchange.
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Open Access
Transitional housing as an inclusionary planning intervention: The pickwick transitional housing project
(2024) Siff, Enrique; Winkler, Tanja
This dissertation explores if and how transitional housing, as a state intervention, enhance the inclusion of disenfranchised residents in well-located neighbourhoods. The City has often been criticised for relocating evictees to its Temporary Relocation Areas (TRAs) on the urban edge, away from the city centres and places of employment. At least 75% of Cape Town's households continue to be excluded from accessing centrally located municipal services (Ndifuna Ukwazi, 2021), whilst ongoing evictions and displacements of hundreds of families from inner-city neighbourhoods culminate in “a systemic crisis that has been going on for over a decade” (Pillay, et al., 2017:2; also see Le Grange, 1985). In response to the ongoing housing crisis, transitional housing is increasingly being advocated for by state entities and non-government organisations (NGOs) as an alternative housing model to remedy aspects of the ever-escalating demands for affordable accommodation in Cape Town (and elsewhere in South Africa and globally). As such, this dissertation explore if and how the Pickwick Transitional Housing project meets the City's commitment and mandate to enable a more integrated and inclusive city for all. This research is explored by deploying discourse analysis and the case study methods (semistructure interviews and mapping research techniques). It focused on the Pickwick Transitional housing pilot project in Salt River, Cape Town as the case under study. It investigated a case of a group of people who had originally lived nearby in Woodstock, Cape Town, but who were ultimately forced to settle informally in the neighbourhood and had been relocated to the Pickwick facility in Salt River. Key discussions presented throughout this dissertation thus focus on: (1) the significance of transitional housing in enabling integrated and inclusive spatial planning outcomes; (2) the role of transitional housing in facilitating affordable housing options for poor and working-class residents in well-located areas; and (3) the prospects of transitional housing becoming alternative, and formal, mechanisms to remedy evictions and displacements from inner-city neighbourhoods undergoing gentrification. This research made policy recommendations for transitional housing, as well as recommendations targeted at legislation and some organisations.
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Open Access
The use of simple analytical techniques to assess surface oxidation of sulphide ores
(2024) Sibiya, Ayanda Sikhona; Corin, Kirsten
Surface oxidation is known to have a negative impact on the flotation performance of sulphide minerals. This is because severe oxidation makes it more difficult to process low-grade sulphide minerals, which reduces the recovery of valuable minerals during flotation. It may be possible to quantitatively correlate the rate/level of oxidation to oxidized sulphide ores using simple surface analytical techniques. This, if done well, could eliminate the need for numerous mineralogical tests, saving both time and money. This study investigated the Ethylenediaminetetraacetic acid (EDTA) Extraction Technique and Reactivity Number (RN) Technique as possible techniques to quantitatively describe oxidation levels in different ore types with different mineral compositions and grade. The aim was to determine if the changes in the surface character generated by oxidation are linked to a measurement obtained from the selected techniques. In the thesis, the techniques were validated on fresh ores of differing grades, Impala UG2 referred to as Ore A and High-grade copper ore referred to as Ore B. The two ores were ground to generate varying particle size distributions and liberation profiles to study the link between oxidation, particle size and liberation. Based on ore type and sulphide liberation, the tests attempted to provide an indicator of feed grade and surface oxidation. Flotation is used as a diagnostic tool. For Ore A, results showed that the grind size 60 % -75 µm yielded the highest Cu recovery, the coarsest grind size 40 % -75 µm yielded the second highest Cu recovery, and the grind 80 % -75 µm yielded the lowest Cu recovery. Overall, the Ore A results showed that where the grind sizes had high reactivity (high RN OCF) and high EDTA value, poor flotation recovery was observed and where the OCF and EDTA values were lower, favourable recoveries were obtained. EDTA and RN numbers therefore aided in giving an indication of the extent of oxidation that the ore had undergone, which ultimately translated to flotation recoveries. The grind size 80 % -75 µm had clearly suffered significantly more oxidation than the other grind sizes and this was indicated by the high OCF and the EDTA value and low Cu recoveries. The liberated Base Metal Sulphides (BMS) for Ore B was generally consistent throughout the three grind sizes, however, the highest Cu recovery was achieved by the grind size 80 % -75 µm (95.11 %), followed by grind sizes 60 % -75 µm and 40 % -75 µm respectively (92.25 % and 90.86 %). The recovery of this ore increases as the grind size becomes finer. Ore B demonstrated that, while the OCF and EDTA value for ore B increased as the grind size became finer, so did the recovery. It is possible that the particles that were ground to achieve particle size 80 % -75 µm were at their most hydrophobic state, owing to the increased liberation of the BMS, particularly chalcopyrite.
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Open Access
The impact of FDI on economic growth in South Africa: Does the sector matter?
(2024) Keleme, Mamontshi Gwendoline; Biekpe, Nicholas
Foreign Direct Investment (FDI) is crucial for wealth-creating economic growth. Conceptually, FDI could bridge the investment gap and raise much-needed revenue for South Africa's financial requirements. However, much of the existing evidence on the effects of FDI on economic growth is at the macro level, with scant attention focused on the impact of FDI on economic growth at sector levels in South Africa. Consequently, this study aimed to examine the impact of agricultural, manufacturing, mining, construction, finance, and transport FDI on economic growth for the period 1993 to 2019 in South Africa. The study used panel data to estimate the relationship between the FDI-to-GDP ratio and economic growth. The Panel ARDL results revealed that the effect of sectoral FDI on national GDP was positive but insignificant in the long- and short-run. In addition, the results revealed that domestic investment had a negative and significant effect on growth in the long and short run, at 5% and 10% significant levels, respectively. In line with previous studies, all other variables, such as human capital, trade openness, and total consumption expenditure, had excepted signs in the short run. However, all variables were statistically significant in the long run and had unexpected signs. The short-run PMG result shows that FDI inflows into the construction, mining, and transport sectors had a significant positive relationship with the economic growth rate. In contrast, the FDI inflow in the agriculture, finance and manufacturing sectors had a significant negative relationship with economic growth.