1834 research outputs found
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Patient flow and congestion in the out-patient department at Zithulele hospital
No full textThis thesis considers the causes and effects of congestion in the out-patient department (OPD)
at Zithulele hospital, a rural healthcare facility located in the Eastern Cape province of South
Africa. Detailed mathematical models are developed to analyse the flow of different types of
patients through the OPD and evaluate strategies for reducing the negative effects of congestion.
The OPD model is implemented as a decision support tool which can be used by hospital staff.National Research Foundatio
Whole body modelling of glucose metabolism in malaria patients
No full textDiagnosing a patient with a disease is typically done by considering a list of clinical
symptoms. For severe malaria two of the key pathophysiological indicators for
poor chances of survival are hypoglycemia (blood glucose < 2.2 mmol/L) and lactic
acidosis (blood lactate > 5 mmol/L). These could be due to accelerated glycolytic
flux (conversion of glucose to lactate) in parasite infected red blood cells, anaemia
brought about by the parasites destroying the red blood cells, or reduced perfusion
resulting from coagulation of red blood cells (parasites change the red blood
cell shape) in the bloodstream. To date, no mathematical models exist that can
quantify the relative contribution of increased glycolytic flux to hypoglycemia and
lactic acidosis. In this study we constructed a physiologically relevant model of
human glucose metabolism that contains the molecular mechanisms of erythrocyte
and Plasmodium glycolysis. This allows for the investigation of the extent to which
hypoglycaemia and lactic acidosis can be explained by the increased metabolic burden
of the parasite. This was accomplished by combining three independent models
of glucose metabolism in the parasite, red blood cell and the whole body to form
a model of glucose metabolism at the level of the whole body that now contained
mechanistic detail of reactions at the level of the red blood cell and malaria parasite
(the green1 model). Predictions from the green1 model were compared to clinical
data which showed that the increased glycolytic flux caused by the presence of the
parasites could be sufficient to explain clinical symptoms of hypoglycemia and lactic
acidosis seen in malaria patients. It was seen that for the strength of this modelling
technique to be tested, better quality data are needed to validate the model predictions. Furthermore with local and global sensitivity analysis it was observed
that there are reactions and parameters in the Plasmodium glycolysis pathway that
could guide the development of possible drug targets that could lead to a reversal
of hypoglycemia and lactic acidosis.National Research Foundatio
A review of the China – Africa arms trade and its relationship to issues of gender and human security
No full textAs emerging powers in Africa aim to secure resources, the relationship between China and
Africa has been scrutinized regarding China’s arms transfers to fragile African states. Inquiry
into China-Africa arms transfers led to the studies focus on how these transfers affect African
women’s human security, and to question whether or not there is evidence that China’s arms
transfers to Africa escalate violent conflict. This study determines if there is a correlation
between these factors exist and to what extent China’s small arms transfers affect the
individual security of women in fragile African states. This was researched to raise awareness
to the most salient threats to women’s human security in Africa. Throughout this study, the
small arms and light weapons supplied by China to Africa have been found to be both direct
and indirect causes of these threats.
This research uses perspectives from feminist human security theory, which originally
emerged as a means of consolidating the concepts of individual protection, human rights, and
the welfare of these individuals, to focus on the security of women through human
development and the advancement of international society. Through this perspective it was
discovered that there is a correlation between the China-Africa arms trade and the ongoing
violent conflict in Africa due to the availability of small arms in socio-politically and
economically fragile African states. China has supplied small arms to African states, these
weapons have destabilized the region, exacerbated existing conflicts and provided armed
groups with the ability to attack and oppress women and children. During armed conflicts
women are exposed to increased levels of armed gender based and domestic violence that
include brutal acts of rape, sexual enslavement, torture, and murder perpetrated by state
forces and armed rebel forces. In this regard, China has negatively influenced women’s
human security in these regions, albeit indirectly. While it has always been China’s
responsibility to monitor the effects of its international affairs on African states, it has slowly
begun to adjust its foreign policies to more carefully consider African humanitarian issues.
This study indicates that an important requirement to further reduce the effects of small arms
in Africa is that more stringent and effective arms transfer controls are developed throughout
Africa.
Although African women are victimised by ongoing arms proliferation throughout Africa,
their activism and inclusion in peace negotiations and post-conflict disarmament and
reintegration operations, is potentially the most important source of resistance to the effects
of armed violence in Africa. It is therefore important to formally include women in African
peace processes and operations to be able to improve women’s human security in Africa. The
inclusion of African women can potentially improve the outcome of these operations,
ultimately determining how successful they are at reducing the effects of armed violence.
This research will hopefully improve international awareness of the current situation in
women’s human security in Africa. To further underestimate and ignore the potential
influence of women as crucial actors in preventing and mitigating the effects of armed
conflict will lead to peace-making and peace-building efforts remaining ineffectual at
producing sustainable long-term solutions towards peace, stability and security in AfricaNational Research Foundatio
Storytelling and social commentary in a comparison of Zakes Mda's Ways of dying (1995) and black diamond (2009)
No full textIn a comparison of two novels, Ways of Dying (1995) and Black Diamond (2009), this dissertation examines Zakes Mda's ongoing use of fiction in presenting incisive social commentary in the post-apartheid literary context. Mda's debut novel is a complex magic realist tale of Toloki, the professional mourner, who journeys from the village to the urban township. It is markedly different from his post-millennial satire, which invokes the social realist form, constructing a rapidly unfolding plot of urban gangsters, crime and sex, in which the characters are more representational than well-developed. While Ways of Dying has been praised as Mda's thought-provoking novel of the transition, Black Diamond has sometimes been criticised as being less able to comment significantly on the state of post-millennial South Africa. Subsequently, this dissertation evaluates the potential of Mda's most recent fictional portrayal of post-apartheid society to provide a meaningful interpretation of and commentary on post-apartheid South Africa, alongside his earlier novel.National Research Foundatio
A framework for information security management in local government
No full textInformation has become so pervasive within enterprises and everyday life,
that it is almost indispensable. This is clear as information has become core
to the business operations of any enterprise. Information and communication
technology (ICT) systems are heavily relied upon to store, process and
transmit this valuable commodity. Due to its immense value, information
and related ICT resources have to be adequately protected. This protection
of information is commonly referred to as information security.
Information security risks are a strategic issue which should be thoroughly
addressed by all enterprises, public and private in nature. Local government
in South Africa are no different. However, the Auditor-General of South
Africa deems the majority of information security practices within local government
to be inadequate.
Therefore, the objective of this research study was to address this issue
by designing an artefact. Consequently, this research naturally followed a
design-oriented approach. The artefact of this research took the form of a
framework. The framework is titled ‘A Framework for Information Security
Management in Local Government (FISM)’. FISM was developed in a fourphased
iterative approach, in collaboration with stakeholders within local
government.
FISM incorporated several criteria which address the unique challenges
of local government. These criteria was evaluated by conducting a workshop
exercise which was attended by several local government representatives. The
results of the validation workshop was good and deemed FISM to adhere to
the criteria it set out to meet. Consequently, this research study attained the
primary objective it set out to meet, which was to develop FISM in order to
address the real-world problem at hand.National Research Foundatio
Precipitation and valorisation of lignin obtained from South African kraft mill black liquor
No full textNational Research Foundatio
Essential professional competencies of social work supervisors in a non-profit welfare organisation
No full textSocial work supervisors who possess essential professional competencies will have a positive
influence on their supervisee, the organisation, and the end service user. They bring about
professional growth and change, which encourages the development and maturity of the social
worker, resulting in optimum practice. These are key responsibilities of the supervisor, who
should be competent to offer supervision at a level that is beneficial to the ecosystem of
supervision within the organisation.
According to South African policy documents, social work supervisors should be competent to
fulfil the expectations and requirements of their position. This implies that supervisors are
equipped for their position as social work supervisors, and that they possess the skills,
knowledge and experience that are critical for social work supervisors. However, the literature
reveals that supervisors are not well prepared for their position, they do not receive training
prior to their appointment, and there is no focus on the identification or development of their
competencies. There are no policy documents or research papers that explore the essential
professional competencies of supervisors. This aspect is critical to examine further, as there is
an identified need in South African policy documents to increase the retention and quality of
services of social workers, and competent supervisors can contribute significantly to solving
this problem. A competent supervisor will lead to a competent supervisee, thus benefitting the
organisation and the service user.
This study explored and described the essential professional competencies of social work
supervisors in a non-profit welfare organisation. This was done by examining which
competencies are deemed essential for supervisors, and how they are implemented or
experienced. By exploring a conceptual framework for supervisors in South Africa and
considering a model and definition of competence within the context, the development and
importance of professional competencies could be better understood and explored.
An instrumental case study design was deemed the most appropriate design for the research,
as it provided a clear context for the research topic to be explored. The study further assumed
an exploratory and descriptive research design in order to provide a detailed description of the
phenomenon being studied, namely the essential professional competencies of social work
supervisors. A qualitative approach was used in the study in order to explore the topic at hand,
as it was complementary to the explorative and descriptive research design. Data was gathered
Stellenbosch University https://scholar.sun.ac.za
by means of a semi-structured interview schedule, which was administered during individual
face-to-face or telephonic interviews. This allowed for data to be gathered that provided a rich
description of the research topic. The design of the semi-structured interview schedule was
based on the information obtained from the literature review chapters.
The findings from the empirical investigation reveal that the two main categories in which
supervisors should be competent are foundational and functional competencies. Foundational
competencies include four subthemes, namely that supervisors should be competent in:
emotional intelligence; anti-discriminatory supervisory practices; professional relationships;
and ethical practices and legal knowledge. The functional competencies focused on three main
subthemes, namely that supervisors should be competent in: balancing the three supervision
functions (administration, education and support); implementing the supervision process; and
possessing specific managerial competencies for the non-profit organisation (NPO) sector.
The findings indicate that supervisors are not fully equipped for their position, and that they
require training and equipping in order to understand and implement the competencies that are
essential for their practice. Furthermore, the findings show that supervisors have a high
workload, they are responsible for a large number of staff, and their supervisory responsibilities
are often over-shadowed by structural issues. Supervisors in South Africa need to be competent
in balancing their supervision responsibilities alongside the middle management
responsibilities that they are expected to bear.
Recommendations were made on four of the systems involved in supervision. Specific
recommendations were made for each theme, subtheme and category. The general
recommendations focus on: supervisors prioritising their competencies and creating
opportunities to practise them and improve in them; organisations needing to emphasise the
importance of professional competencies, specify them in supervisors’ job descriptions and
encourage opportunities for competencies to be learnt and practised; training institutions
needing to offer more training in foundational and functional competencies, on both an
undergraduate and postgraduate level; and finally, ethical and legal bodies needing to
incorporate competencies into policy documents and to facilitate national development
programmes to operationalise foundational and functional competencies.National Research Foundatio
Annual performance plan, 2017/20
No full textThe NRF is securing a
brighter future for South
Africa and its citizens by
promoting and supporting
research excellence, human
capacity development and
creation of a knowledge
society
Fusaric acid induces oxidative stress and apoptosis in human oesophageal cancer cells
No full textBackground/Aims: The incidence of oesophageal cancer (OC) is a worldwide problem and is
incremental among black South African males. The high prevalence of OC may be due to the
consumption of maize as a staple, often contaminated with mycotoxins. Fusaric acid (FA), a
neglected mycotoxin, was first isolated from Fusarium heterosporum and a major contaminant
of maize. FA is known to disrupt mitochondrial energy metabolism, chelate divalent metal
cations, induce cell death in plants, and has been suggested as an aetiological agent of OC.
However, the mechanism by which FA causes cytotoxicity in oesophageal cells has not been
conclusively elucidated. This study investigated FA-induced cytotoxicity and apoptotic
induction in the SNO OC cell line.
Methods: SNO cells were treated with a range of FA concentrations (0-500 µg/ml) over 24 h
and an IC50 was obtained using the MTT assay. The cells were assayed for oxidative stress and
membrane damage (TBARS, LDH cytotoxicity and glutathione), apoptotic induction (ATP
levels, caspase-8, -9, -3/7 activities) (Luminometry), single strand DNA and nuclear
fragmentation (Comet and Hoechst assay). Additionally, relative expression of pro- and antiapoptotic
proteins were determined using Western Blotting.
Results: An IC50 of 78.81 µg/ml FA was obtained. Significant antioxidant (glutathione)
depletion (1.62-fold, p < 0.0001) was consistent with a concomitant increase in reactive oxygen
species (ROS)-induced lipid peroxidation (1.23-fold, p < 0.05) and extracellular LDH levels
(1.15-fold, p < 0.005). FA induced apoptosis by significantly increasing Bax expression (1.08-
fold, p < 0.05) and caspase-8, -9 and -3/7 activities (p < 0.05) whilst decreasing ATP levels
(1.16-fold, p < 0.05) and Bcl-2 expression (1.24-fold, p < 0.05). Further, FA significantly
increased comet tail lengths (p < 0.0001), PARP-1 cleavage (1.53-fold, p < 0.05) and late stage
apoptotic body formation in SNO cells.
Conclusion: FA induced oxidative stress by increasing the level of ROS-induced lipid
peroxidation resulting in membrane damage and concomitantly reducing antioxidant response,
Disruption of mitochondrial activity was associated with low ATP levels. Collectively, these
events triggered the caspase-cascade which compromised DNA integrity and averted its repair,
leading to cell death via intrinsic and extrinsic apoptosis. Taken together, FA is a cytotoxic
agent to human oesophageal SNO cells.National Research Foundatio
The role of cryptococcal 3-hydroxy fatty acids in mediating cryptococcus-amoebae interactions
No full textIn this dissertation; an attempt was made to elucidate the role of 3-hydroxy C9:0 in determining the fate of cryptococcal cells when acted upon by amoebae. First, it was sought to determine the physiological concentrations of 3-hydroxy C9:0 that were secreted by C. neoformans UOFS Y-1378. Through using LCMS, it was established that cells secreted 0.2 mM of these molecules. Thus, in the design of some studies 1 mM was used in order to establish if a dose-dependent response would be established. The direct effect of these molecules on amoebal growth was next investigated. Here, it was clear that at physiological concentrations, these 3-hydroxy fatty acids did not negatively affect the growth of amoebae. This finding was critical as it pointed that these molecules probably effected a signalling mechanism in amoebae that may promote the survival of cryptococcal cells when interacting with amoebae. Could the concerned mechanism involve phagocytosis? To answer this question, co-culture experiments were designed wherein cryptococcal cells were deliberately fed to amoebae and in some experiments 3-hydroxy C9:0 was added to the co-culture media. It became evident that cryptococcal cells, which did not naturally produce 3-hydroxy C9:0, were more readily: 1) internalised, and 2) phagocytosed by amoebae. Interestingly, when 3-hydroxy C9:0 was artificially added (to the co-culture media) the cryptococcal cells became resistant to amoeba. This response was dose-dependent. Additionally, the strain UOFS Y-1378 (naturally produces 3-hydroxy C9:0) was more resistant to amoeba when compared to the other strains that did not produce 3-hydroxy C9:0. These results suggested that these molecules protected cells against amoebal phagocytosis. To investigate the manner/mechanism(s) through which cells were protected, a number of further experiments were designed. In one experiment, fetuin A was analysed. This protein is reported to be pivotal in enhancing the phagocytic
efficiency of macrophages. Thus, could such a molecule be present in amoeba and important be manipulated by 3-hydroxy C9:0? The data showed that amoebae produced a fetuin A-like molecule. The levels of this molecule were low, similar to levels obtained in the presence GXM, in the presence of 3-hydroxy C9:0. This suggested that 3-hydroxy C9:0 may lower the number of cryptococcal cells that could potentially be internalised by amoebae. Thus, this molecule may be anti-phagocytic. Additionally, it seems that 3-hydroxy C9:0 may also protect cryptococcal cells that could be internalised and exposed to the harsh internal environment of amoebal food vacuole. This assertion was tested after experiments were designed mimicking the internal food vacuole environment. To be specific, it was demonstrated that an acapsular strain that was devoid of 3-hydroxy C9:0 (which in theory should be susceptible to hydrogen peroxide) was resistant when exposed to hydrogen peroxide in the presence of 3-hydroxy C9:0. Moreover, strains that were devoid of 3-hydroxy C9:0 were more susceptible to amoebapore (amoebal anti-microbial peptide found inside the food vacuole) compared to a strain that naturally produces these 3-hydroxy acids. When considering all these results, it is reasonable to suggest that it seems that 3-hydroxy C9:0 protected cells against amoebal phagocytosis. This, therefore, highlights the production pathway of these molecules as targets for developing drugs that may impair the pathogenesis of cryptococcal cells. It was thus not surprising to note that when the strain UOFS Y-1378 was exposed to aspirin, a known inhibitor of 3-hydroxy fatty acid production, its cells became susceptible to amoebal phagocytosis.
The findings recorded in the dissertation also have implications for the fate of cryptococcal cells when acted upon by macrophages. The findings suggest that cells may deploy 3-hydroxy C9:0, possibly in concert with the capsule, in order to evade immuno-processing leading to a diseased-state in a susceptible host. In clinical settings, it is well known that without the prospect of treatment a diseased-host could die within three months when immunocompromised. Thus, the idea would be administering a cheap drug like aspirin could assist in combating cryptococcal infections.National Research Foundatio