Perspectives of Traditional Health Practitioners on the Use of Microbicides for the Prevention of HIV

In many South African communities, Traditional Health Practitioners (THPs) are significant participants within a plural health care system. For several years, it has been argued that this role, especially in the context of HIV/AIDS, has not been fully optimised and THPs continue to operate outside the formal biomedical sector, where the latter forms the central means by which public health campaigns are delivered and implemented. In our previous research, we have shown that this separation of the biomedical and traditional sectors perpetuates a low level of understanding of HIV by THPs with adverse consequences for patients and the overall health care system. In this study we investigated whether biomedical/traditional division could be transformed through the involvement of THPs in the distribution of barrier microbicides; the latter are presently under investigation as a means of preventing HIV infection. We concluded that THPs could provide a willing and effective distribution network for the gel-based microbicides; given the large number of THPs and their patients, such a distribution strategy would ensure that microbicides are accessible and adopted relatively quickly within the target  communities of the HIV prevention campaigns.Keywords: Traditional Health Practitioners, HIV, AIDS, prevention, microbicides

The role of South African traditional health practitioners in the treatment of HIV/Aids: a study of their practices and use of herbal medicines

Background. A large proportion of HIV-positive South Africans regularly consult traditional health practitioners (THPs) for their health care needs, despite evidence of negative interactions with antiretrovirals (ARVs) and no published peer-reviewed clinical evidence for the efficacy of traditional medicines in the treatment of HIV. We investigated the dominant practices of THPs towards HIV-positive patients and whether these practices have changed following widespread public awareness campaigns covering HIV and its treatment. Method. The study used a semi-structured interviewer-administered questionnaire in the home language of the interviewee. A total of 52 THPs from four provinces (Gauteng, Limpopo, KwaZulu-Natal and Eastern Cape) were interviewed. Of the respondents 38% were based in the rural areas, and 69% classified themselves as inyangas, the remainder being sangomas. Findings. All the THPs in the survey offered treatment for HIV, although only 20% claimed to be able to cure the disease; 88% prepared their own medication, mostly from plant material, and sold their products as aqueous extracts in labelled bottles. None of these products had been systematically evaluated, and there was generally no record keeping, either of the patient or of the medicine itself. Quality control practices such as expiry dates, controlled storage conditions and batch records were totally unknown in our sample. Only 38% of the THPs had received training on HIV/AIDS, although 75% believed that they were well informed about the disease. Our own assessment was that only 50% had a working knowledge of HIV; more disturbingly, 37% believed that only traditional medicines should be used for its treatment and a further 50% believed that traditional medicines and ARVs can be taken simultaneously. Interpretation. Despite ongoing public educational campaigns on HIV, some of which have specifically targeted THPs, the care of HIV-positive patients continues to be compromised by the traditional sector. Although some progress is evident, THP approaches to HIV treatment fail to conform to minimum standards proposed by the World Health Organization and other organisations, and represent a considerable challenge to the integration of THPs with the biomedical sector and the antiretroviral treatment programme in South Africa

Structured Analysis Reveals Fundamental Mathematical Relationships between Wind and Solar Generations and the United Kingdom Electricity System

The use of wind and solar generation is fundamental to the decarbonisation of the United Kingdom electricity system. However, the optimal level of renewable energy as a proportion of total demand is still being debated. In this paper, several models, whose aims are to predict the efficiency of future system configurations, are explained. The models use historic records from the Gridwatch website for the year 2017, which are then scaled accordingly. The model predictions are first demonstrated for the 2035 Scenario as proposed by the National Grid in FES 2022. The analysis reveals that at least one third of the available wind and solar generation will exceed the ability of the electricity system to use it and will have to be shed. By defining an efficiency measure, the Marginal Decarbonisation Efficiency, which quantifies the incremental extent to which wind generation can decarbonise the electricity system, it is shown that the 2035 Scenario will have a low efficiency. Moreover, it will require the use of combined cycle gas turbines, which is at variants with the predictions of the National Grid steady state model. The paper also describes the derivation of a Generic Model, which allows the level of wind energy and dispatchable generation for all system configurations likely to be encountered in future decades, to be calculated without the use of computer models.Comment: 17 pages, 7 figures, 1 table, unpublished pape

An exploratory study of the South African concentrated solar power sector using the technological innovation systems framework

Abstract: Wide-scale deployment of variable renewable energy (wind and solar photovoltaic) is constrained by its associated requirements for energy storage, the technologies for which are currently too expensive to be routinely used. Concentrated solar power (CSP), with its inherent storage capacity, offers semi-dispatchable electricity at large scale. However, its deployment to date has been restricted by high capital costs and the limited geographical locations with optimal solar radiation to attain required efficiencies. South Africa, with its abundant solar resources, has the potential to develop an export-competitive CSP industry by leveraging existing capabilities in innovation, manufacturing and construction, but has yet to attain this goal. This study applied a qualitative, exploratory approach and the framework of technological innovation systems (TIS) to understand the factors that are currently prohibiting the country from being a global leader in CSP. The assessment has revealed the presence of largely immature TIS, characterised by a heavy reliance on imported technology and market support from the state-supported procurement programme. The advancement of CSP remains contingent on further allocation of CSP procurement targets in this programme and sufficient support to develop entrepreneurial activity. An integrated industrial policy strategy, which can ensure technology transfer and address the high cost of CSP, is recommended as a means of addressing the barriers to its development as a competitive industry

Development of Mathematical Models to Explore the Potential of Wind Fleets to Decarbonize Electricity Grid Systems

Real-time records of energy generation in the UK and Germany have been used to develop models for each country’s electricity generation system, the objective being to provide a means of determining the likely economic limits of wind fleets and their consequent ability to decarbonise their grids. The results from the models, expressed in the form of marginal efficiencies, have then been codified in a pair of simple look-up tables, obviating the need for further reference to the models and providing a simple means of assessing the implications for the grids and their wind fleets of a range of future grid configurations, including increases in wind and solar fleet capacities, anticipated future loss in both countries of nuclear-generating capacity, possible replacement of petrol and diesel passenger vehicles with electric vehicles, and, for the UK only, the conversion of domestic boilers from gas to electricity. It is apparent that headroom, being the difference between annual average grid demand and base generation, is the single most important factor in determining how much wind capacity may be economically deployed in decarbonising grids

The Development of Investment Planning Models for the United Kingdoms Wind and Solar Fleets

Previous work has resulted in the development of an energy model able to calculate wind and solar fleet efficiencies. However, for investment planning purposes, it is necessary to calculate from the lowest economically acceptable efficiencies how much wind and solar generation would be economically justified. The paper explains how this objective has been achieved with arrays (investment planning tables) created after carrying out a structured investigation of the behaviour of the electricity system over the whole of its operational range. The tables are then applied to National Grid prediction of the size and composition of the system in the year 2035. A conclusion is reached that wind and solar generation will only be able to supply about 70% of electrical demand, the other 30% being provided by dispatchable sources of generation, which must be sufficiently fast acting to maintain electricity system stability, such as the use of combined cycle gas turbines. This limit on deployment of wind and solar generation restricts their ability to decarbonise the electricity system and is likely to lead in 2035 to a residual of 72 million tonnes per annum of carbon dioxide emissions which wind and solar generations will be unable to addressComment: 16 pages, 6 figures, 5 table

Efficient and flexible simulation-based sample size determination for clinical trials with multiple design parameters

Simulation offers a simple and flexible way to estimate the power of a clinical trial when analytic formulae are not available. The computational burden of using simulation has, however, restricted its application to only the simplest of sample size determination problems, often minimising a single parameter (the overall sample size) subject to power being above a target level. We describe a general framework for solving simulation-based sample size determination problems with several design parameters over which to optimise and several conflicting criteria to be minimised. The method is based on an established global optimisation algorithm widely used in the design and analysis of computer experiments, using a non-parametric regression model as an approximation of the true underlying power function. The method is flexible, can be used for almost any problem for which power can be estimated using simulation, and can be implemented using existing statistical software packages. We illustrate its application to a sample size determination problem involving complex clustering structures, two primary endpoints and small sample considerations