Browsing by Author "van Wyk, B."

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    Borehole dilution experiment in a Karoo aquifer in Bloemfontein
    (Water Research Commission, 1997) Xu, Yongxin; van Tonder, Gerrit J.; van Wyk, B.; van Wyk, E.; Aleobua, B.
    This paper shows that a borehole dilution experiment using common salt is a useful technique for better understanding of some hydrogeological features of a fractured aquifer. A sense of such tracer experiments was performed in the campus site aquifer, a hydrological experiment site of the Institute for Ground Studies at the University of the Orange Free State in Bloemfontein. It is demonstrated that the model for use in homogeneous aquifers may be adapted in fractured aquifers. Results have revealed valuable information on hydraulic parameters of the fracture system at different scales. Profiles of electrical conductivities monitored in several boreholes can be used to locate horizontal fracture zones in the aquifer. These results may provide an important guide to formulate realistic conceptual models for borehole protection zoning. The experiment can also serve as a reference to future experiments of this kind in Karoo aquifers which cover some 50% of the subcontinent of Southern Africa.
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    The impact of HIV infection and disease stage on the rate of weight gain and duration of refeeding and treatment in severely malnourished children in rural South African hospitals
    (Health and Medical Publishing Group, 2017) Muzigaba, M.; Sartorius, B.; Puoane, Thandi; van Wyk, B.; Sanders, David
    BACKGROUND: Evidence of the effects of HIV infection and clinical stage on the duration of refeeding and treatment (DRT) and the rate of weight gain (RWG) in severely malnourished children remains inconclusive. OBJECTIVES: To determine whether the RWG and DRT differ by baseline clinical characteristics, and to assess the effect of HIV status and disease stage on the relationship between these two clinical outcomes. METHODS: This was a retrospective record review of 346 patiens discharged between 2009 and 2013 following treatment for severe acute malnutrition (SAM) at two rural hospitals in South Africa. RESULTS: A third of the sample was HIV-positive, the RWG (measured as g/kg/day) was significantly slower in HIV-positive patients compared with HIV-negative cases (mean 5.2, 95% confidence interval (CI) 4.47 - 5.93 v. mean 8.51; CI 7.98 - 9.05; p<0.0001) and cases at stage IV of HIV infection had a significantly slower RWG (mean 3.97; CI 2.33 - 5.61) compared with those at stages I (mean 7.64; CI 6.21 - 9.07) (p<0.0001) and II (mean 5.87; CI 4.74 - 6.99). The mean DRT was longer in HIV-positive cases and those at advanced stages of HIV infection. HIV-positive cases were renourished and treated for almost 3.5 times longer than their HIV-negative counterparts to achieve a moderate RWG (5 - 10 g/kg/day). CONCLUSION: This study highlights the need to reconsider energy requirements for HIV-positive cases at different clinical stages, for more rapid nutritional recovery in under-resourced settings where prolonged hospitalisation may be a challenge.