Kuntanshi yamikalile (The Future): speculative nonconformity in the works of Zambian visual artists
- Authors: Mulenga, Andrew Mukuka
- Date: 2021
- Subjects: Future in art , Africa -- In art , Art, Zambian , Art, African , Artists -- Zambia , Nyandoro, Gareth
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172203 , vital:42175 , 10.21504/10962/172203
- Description: In recent years, select African visual artists practising on the continent as well as in its diaspora have increasingly been attracted to themes that explore, portray or grapple with Africa’s future. Along with this increasing popularity of the ‘future’ or indeed ‘African futuristic’ themes by visual artists, such themes have also attracted academic consideration among various scholars, resulting primarily in topics described as ‘African Futurism’ or Afrofuturism. These are topics that may be used to disrupt what some scholars – across disciplines and in various contexts – have highlighted as the persistent presumptive notions that portray Africa as a hinterland (Hassan 1999; Sefa Dei, Hall and Goldin Rosenberg 2000; Simbao 2007; Soyinka-Airewele and Edozie 2010; Moyo 2013; Keita, L. 2014; Green 2014; Serpell 2016). This study makes an effort to critique certain aspects of ‘African Art History’ with regard to the representation of Africa, and raises the following question: How can an analysis of artistic portrayals of ‘the future’ portrayed in the works of select contemporary Zambian artists be used to critique the positioning of Africa as ‘backward’, an occurrence at the intersection of a dualistic framing of tradition versus modern. Furthermore, how can this be used to break down this dichotomy in order to challenge lingering perceptions of African belatedness? The study analyses ways in which this belatedness is challenged by the juxtaposition of traditional, contemporary and futuristic elements by discussing a series of topics and debates associated to African cultures and technology that may be deemed disconnected from the contemporary lived experiences of Africans based on the continent. The study acknowledges that there is no singular ‘African Art History’ that one can talk of and there have been various shifts in how it has been perceived. I argue that while currently the African art history that is written in the West does not simplistically position Africa as backward as it may have done in the past, there appear to be moments of a hangover of this perception (Lamp 1999:4). What started out as a largely Western scholarly discourse of African art history occurred in about the 1950s and the journal African Arts started in the 1960s. Even before contemporary African art became a big thing in the 1990s for the largely US- and Europe-based discourses there were many discussions in the US about how the ‘old’ art history tended to freeze time and that this was not appropriate (Drewal 1991 et al). In order to advance the discourse on contemporary African visual arts I present critical analyses of the select works of Zambian artists to develop interpretations of the broader uses of the aforementioned themes. The evidence that supports the core argument of this research is embedded in the images discussed throughout this dissertation. The artists featured in the study span several decades including artists who were active from the 1960s to the 1980s, such as Henry Tayali and Akwila Simpasa, as well as artists who have been practising since the 1980s, such as Chishimba Chansa and William Miko and those that are more current and have been producing work from the early 1990s and 2000s, such as Zenzele Chulu, Milumbe Haimbe, Stary Mwaba, Isaac Kalambata and Roy Jethro Phiri.
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Lipid nanocarriers : a novel approach to delivering ophthalmic clarithromycin
- Authors: Makoni, Pedzisai Anotida
- Date: 2021
- Subjects: Clarithromycin , Nanomedicine , Nanostructures , Antibiotics , Eye -- Diseases -- Treatment , Ocular pharmacology , Ophthalmic drugs , Karatitis -- Chemotherapy
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171678 , vital:42109 , 10.21504/10962/171678
- Description: The feasibility of incorporating clarithromycin (CLA) into innovative solid lipid nanoparticles (SLN) and nanostructured lipi d carriers (NLC) using hot emulsification ultrasonication (HEUS) was investigated. This approach was investigated in an attempt to address the shortcomings associated with the use of lyophilized parenteral formulations administered via the ocular route suc h as toxic reactions, intolerance and patient discomfort due to frequent insti llation of topical solutions of CLA. In particular, sustained release approaches to delivery may enhance precorneal retention, increase ocular availability and permit dose reduction or use of a longer dosing frequency when treating ocular non - tuberculous m ycobacterial (NTM) keratitis infections. This approach may potentially improve the delivery of CLA to the eye, thereby addressing some or all of the unmet clinical needs described vide infra . Prior to initiating pre - formulation, formulation development a nd optimization studies of CLA - loaded SLN and/or NLC, Design of Experiments (DoE), specifically a Central Composite Design (CCD) was used in conjunction with Response Surface Methodology (RSM) to develop and optimize a suitable method for the quantitative determination of CLA in pharmaceutical formulations and for monitoring CLA release from SLN and/or NLC in vitro . A simple, accurate, precise, sensitive and stability - indicating reversed phase - high performance liquid chromatography (RP - HPLC) method with ele ctrochemical (EC) detection was developed, validated and optimized for the in vitro analysis of CLA loaded SLN and/or NLC formulations. Pre - formulation studies were undertaken to investigate the thermal stability of CLA and bulk lipids to facilitate the s election of lipid excipients for the manufacture of nanocarriers in addition to establishing compatibility of CLA with the excipients. It was established that CLA was thermostable up to a temperature of approximately 300 °C thereby indicating that HEUS cou ld be used for the manufacture of CLA - loaded SLN and/or NLC. Lipid screening revealed that CLA i s, in general, poorly soluble in solid and liquid lipids however a combination of stearic acid (SA) and Transcutol ® HP (THP) exhibited the best dissolution pote ntial for CLA of all lipids tested . Stearic acid appears to exist as polymorphic form B prior to exposure to heat however occurs as the form C polymorph following heating at 85 °C for one hour. The best ratio for the mixture of SA and THP for the manufactu re of CLA - NLC ii was an 80:20 ( w/w ) ratio of SA: THP as the two lipids are miscible in this ratio and exhibited the greatest dissolution potential for CLA. Furthermore, an investigation of binary mixtures of CLA/SA and SA/Transcutol ® HP, in addition to eutect ic mixtures of CLA, SA and Transcutol ® HP, revealed no obvious interaction between CLA and the lipids selected for the production of the nanocarriers. Due to the relatively high solubility of CLA in THP in comparison to SA, NLC are likely to exhibit a hig her loading capacity (LC) and encapsulation efficiency (EE) for CLA than SLN. Consequently the feasibility of incorporating CLA (10% w/w ) into NLC was investigated and evaluation of the production of SLN was not undertaken as the production of these might not result in the manufacture of a delivery technology with a high EE and LC for CLA. Tween ® 20 was used as the surfactant as it is readily available, exhibits little or no cytotoxicity and is relatively cheap. Polyethylene glycol (PEG) was used as a coati ng polymer to impart muco - adhesive properties the formulated CLA - NLC. Response surface methodology (RSM) in conjunction with DoE, specifically a Box - Behnken Design (BBD) used as a screening design was used to identify a formulation composition which would produce a product that would meet the pre - defined target critical quality attributes (CQA) for the nanoparticles viz. particle size (PS) in the nano - range, polydispersity index (PDI) < 0.5, Zeta Potential (ZP) ≥ ± 30 mV, and EE > 80%. The formulation composition identified was subsequently used for the optimization of the manufacturing parameters viz. sonication time and amplitude, using a Central Composite Design (CCD) . The LC and EE, in vitro CLA release, cytotoxicity, osmolarity, pH, degree of crystallinity and lipid modification, elemental analysis and surface morphology of the optimized batch was investigated and mon itored to ensure that CLA - loaded NLC, of the desirable quality, had been produced. On the day of manufacture the mean PS and PDI of the optimized CLA - loaded NLC formulation adjusted to physiological osmolarity (250 – 450 mOsm/kg) was 461.9 ± 40.16 nm and 0. 523 ± 0.104, respectively. The ZP for the optimized NLC generated on the day of manufacture using HPLC grade water as the dispersion medium was - 20.5 ± 4.82 mV. The pH and osmolarity of the optimized CLA - loaded NLC formulation was 7.76 ± 0.01 and 316 ± iii 2 m Osm/Kg, respectively and the EE was 88.62 ± 0.23 %. The optimized NLC exhibited a decreased crystallinity in comparison to the bulk lipid materials. DSC, WAXS and FT - IR revealed that CLA was molecularly dispersed in the nanocarriers. The optimized CLA - load ed NLC exhibited muco - adhesive properties, when tested under stationary conditions using laser doppler anemometry (LDA). The optimized formulation also exhibited sustained release of CLA over 24 hours during in vitro release testing and CLA release was bes t described using the Baker - Lonsdale model . The cumulative % CLA released over 24 hours was 56.13 ± 0.23% and mass balance analysis revealed 41.38 ± 0.02% CLA had been retained in the NLC. In vitro cytotoxicity testing revealed that the optimized CLA - NLC w ere less cytotoxic to HeLa cells when compared to CLA alone and further confirmed that the lipids and excipients used in these studies were of GRAS status . Stability studies revealed that the EE reduced over 28 days by 14.42% and 5.14% when stored at 4 °C and 22 °C , respectively. In addition, the particle size increased from the nm to μm range for samples stored at 22 °C. The findings are a good starting point but require further optimization to ensure prolongation of stability. In addition , the technology requires additional developmental studies and a powder for reconstitution for use as a single - dose considered as single dose packaging may be a solution to the compromised formulation stability observed in these studies. The CLA - NLC produced in these stu dies exhibit sound product attributes which serve as a useful foundation for the novel delivery of antibiotics to the eye. The results suggest that the optimized NLC have the potential to enhance precorneal retention and increase ocular availability of CLA , which in turn may be useful to reduce the required dose and dosing frequency when administering CLA as a reconstituted solution to treat susceptible organisms that infect ocular tissues.
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Parametrised gains for direction-dependent calibration
- Authors: Russeeaeon, Cyndie
- Date: 2021
- Subjects: Radio astronomy , Radio inferometers , Radio inferometers -- Calibration
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172400 , vital:42196
- Description: Calibration in radio interferometry describes the process of estimating and correcting for instrumental errors from data. Direction-Dependent (DD) calibration entails correcting for corruptions which vary across the sky. For small field of view observations, DD corruptions can be ignored but for wide fild observations, it is crucial to account for them. Traditional maximum likelihood calibration is not necessarily efficient in low signal-to-noise ratio (SNR) scenarios and this can lead to ovefitting. This can bias continuum subtraction and hence, restrict the spectral line studies. Since DD effects are expected to vary smoothly across the sky, the gains can be parametrised as a smooth function of the sky coordinates. Hence, we implement a solver where the atmosphere is modelled using a time-variant 2-dimensional phase screen with an arbitrary known frequency dependence. We assume arbitrary linear basis functions for the gains over the phase screen. The implemented solver is ptimised using the diagonal approximation of the Hessian as shown in previous studies. We present a few simulations to illustrate the performance of the solver.
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Prioritising biological control agents for release against Sporobolus pyramidalis and Sporobolus natalensis (Poaceae) in Australia
- Authors: Sutton, Guy Frederick
- Date: 2021
- Subjects: Grasses -- Diseases and pests , Bruchophagus , Wasps , Alien plants -- Biological control -- Australia , Sporobolus -- Biological control -- Africa , Sporobolus -- Biological control -- Australia , Insects as biological pest control agents -- Australia , Insects as biological pest control agents -- Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172445 , vital:42201 , 10.21504/10962/172445
- Description: Sporobolus pyramidalis Beauv. and S. natalensis (Steud.) Th. Dur. and Schinz. (giant rat’s tail grass) (Poaceae), invade rangelands and pastures in eastern Australia, costing the livestock industry approximately AUS$ 60 million per annum in grazing losses. Mechanical and chemical control options are costly and largely ineffective. Biological control is viewed as the most promising control option, however this management strategy has largely been avoided for grasses, due to their perceived lack of suitably host-specific and damaging natural enemies. In this thesis, the prospects for using biological control against S. pyramidalis and S. natalensis in Australia was assessed, in light of these potential challenges. Climate matching models were used to identify high-priority geographic regions within the plants’ native distributions to survey for potential biological control agents. High-priority regions to perform surveys were identified by modelling the climatic suitability for S. pyramidalis and S. natalensis in sub-Saharan Africa (i.e. their potential native ranges’), and climatic compatibility with regions where biological control is intended in Australia. High-priority regions for S. pyramidalis included: (1) coastal East Africa, ranging from north-eastern South Africa to Uganda, including south-eastern DRC, (2) some parts of West Africa, including inland regions of the Ivory Coast and western Nigeria, (3) northern Angola and (4) eastern Madagascar, and for S. natalensis included: (1) eastern South Africa, (2) eastern Zimbabwe, (3) Burundi, (4) central Ethiopia and (5) central Madagascar. Prospective control agents collected from these regions have the highest probability of establishing and proliferating in Australia, if released. In surveys of the insect assemblages on S. pyramidalis and S. natalensis in the climatically-matched region of eastern South Africa fifteen insect herbivores associated with the grasses were identified. Insect feeding guild, geographic distributions, and seasonal abundances suggest that three stem-boring phytophagous wasps, Tetramesa sp. 1, Tetramesa sp. 2 and Bruchophagus sp. 1 (Hymenoptera: Eurytomidae), have potential as control agents. Species accumulation curves indicated that additional surveys in South Africa are unlikely to yield additional potential control agents. Field host-range surveys of 47 non-target grass species in South Africa showed that Tetramesa sp. 1, Tetramesa sp. 2, and Bruchophagus sp. 1, were only recorded from S. pyramidalis and S. natalensis. Integrating field host-range with phylogenetic relationships between plant species indicated that no native Australian Sporobolus species or economic crops and pastures are expected to be attacked by these wasps. All three wasp species are predicted to be suitably host-specific for release in Australia. Three other endophagous herbivores attacked non-target native African Sporobolus species that share a close phylogenetic relationship to native Australian Sporobolus species, and therefore, demonstrate considerable risk of non-target damage. These species should not be considered as potential control agents. Under native-range, open-field conditions, Tetramesa sp. 1 caused an approximately 5-fold greater reduction in plant survival and reproductive output than Tetramesa sp. 2 and Bruchophagus sp. 1. Tetramesa sp. 1 in combination with Tetramesa sp. 2 did not significantly increase the level of damage, while Bruchophagus sp. 1 may decrease the efficiency of Tetramesa sp. 1, if released in combination. Tetramesa 1 is therefore the most promising candidate agent. Prioritising potential agents using predicted efficacy allowed otherwise equally suitable prospective agents to be prioritised in a strategic manner. Prioritising which natural enemies to target as biological control agents is a complex task. Field host range and damage assessments in the native range may provide more realistic data than typical studies performed under artificial conditions in a laboratory or quarantine. Moreover, it could assist practitioners in prioritising the most suitable agent(s) at the earliest stage in the programme as possible. This study demonstrated that grasses are suitable targets for biological control as they can harbour host-specific and damaging natural enemies.
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Synthesis, spectroscopic and nonlinear optical properties of asymmetric A3B type phthalocyanine complexes
- Authors: Mugeza, Rhulani Donney
- Date: 2021
- Subjects: Spectrum analysis , Mass spectrometry , Phthalocyanines
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171667 , vital:42108
- Description: This work reports on the synthesis of symmetrical and asymmetrical A 3 B type metal free, cobalt and zinc Phthalocyanines (Pc) .A wide range of spectroscopic techniques such as Uv - visible absorption (UV), magnetic circular dichroism (MCD), mass spectrometry, elemental analysis, IR spectroscopy and time correlated single photo n counting spectroscopy (TCSPC) have been used to study the spectroscopic properties of the phthalocyanine complexes. The Z - scan technique was used to comparatively investigate the nonlinear absorption coefficient ( 휷 ) and the nonlinear refraction index ( 풏 ퟐ ) of the synthesized complexes. The following trend was obtained for the synthesized Pc’s in terms of the 휷 values 7.25 × 10 − 10 ( 4b ) > 3.76 × 10 − 10 ( 4a ) > 3.52 × 10 − 10 ( 4c ) > 2.29 × 10 − 10 ( 3c ) > 1.68 × 10 − 10 ( 3a ) > 1.65 × 10 − 10 ( 3b ) mW - 1 . The 휷 values trend of synthesized Pc complexes show that the asymmetrical A 3 B type metal free, cobalt and zinc Pc complexes ( 4a , 4b and 4c ) have larger 휷 values as compared to the octa - substituted symmetrical metal free, cobalt and zinc Pc complexes ( 3a , 3b and 3c ) which is attributed to the low symmetry of the Pc complexes. The five - level model rate equations were used to determine the two photon absorption, excited state absorption and ground state absorption cross sections of the synthesized complexes. The z inc A 3 B type asymmetrical Pc complexes gave the largest two photon absorption and 휎 푒 / 휎 푔 ratio values. This Pc complex could be used in future work to enhance the nonlinear response further by introducing nanomaterials and converting the Pc complex to a binuclear Pc. This work also reports on the density functional theory (DFT) calculations o f dipolar/octupolar contributions in order to study the first order hyperpolarizability of the synthesized Pc complexes.
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The application of human factors and ergonomics (HFE) to community-sport organisations in resource scarce contexts: a case study of grassroots football in Makana, Eastern Cape
- Authors: Bennett, Ryan
- Date: 2021
- Subjects: Makana Local Football Association (South Africa) , Human engineering , Soccer teams -- South Africa -- Makhanda -- Management , Soccer -- Management -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172412 , vital:42198 , 10.21504/10962/172412
- Description: Background: Modern Human Factors and Ergonomics (HFE) focuses on the optimisation of complex socio-technical systems and has been challenged to contribute to broader societal issues. An example is within grassroots football organisations in resource-scarce areas such as Makana, South Africa. Through embedded participatory approaches, the research problem was co-constructed: To investigate the socio-technical system of the Makana Local Football Association (LFA). Method: A useful complex system modelling tool is that of Cognitive Work Analysis (CWA), with its 5 phases used to identify constraints and affordances. Three perspectives were adopted for the application of an adapted (to suit participant characteristics) CWA to the Makana LFA: 1) how work is prescribed by the governing body SAFA, 2) how subject matter experts (SME) disclose its current functioning, and 3) how SMEs imagine it could function. Five SMEs attended 12 three-hour workshops to complete the latter two perspectives. Results: The composite work domain analysis between work as prescribed and work as disclosed identified significant mismatches between how policymakers envision the system and how SMEs report its functioning. Key differences in perspectives included the fundamental purpose of the Makana LFA, while only four of 22 functions operate within the Makana LFA. Participants also identified key affordances for the LFA such as reorientation as a community sports organisation. Discussion: Comparison between perspectives indicated four mismatches. 1) SAFA views the LFA as the foundation of the talent identification and development infrastructure of South African football. SMEs view it as a community centred organisation. 2) A lack of human capacity is evident at the community level of Makana football. 3) Funding and assets are absent at this grassroots level. 4) The LFA relies on other stakeholders, but these relationships are not formalised. Policymakers, therefore, have a lack of knowledge of the contextual challenges faced by LFA administrators. It is recommended that SAFA view the LFA as a community sport organisation, focusing on improving human capacity, increasing funding, and formalising stakeholder networks. Furthermore, conceptual models from CWA provide explicit socio-technical system redesign recommendations. Conclusion: Large mismatches between the organising body SAFA and the actual functioning of the LFA significantly hinder the effective management and running of football at a grassroots level in resource-scarce contexts in South Africa. The perspectives approach to CWA was useful in elucidating the constraints and affordances of the Makana LFA socio-technical system and informing redesign opportunities. Systems HFE methodology is therefore well placed to contribute to broader societal issues within resources scarce contexts such as football in Makana. Furthermore, the philosophical underpinnings of systems based HFE were successful in the development of sustainable participatory research within the South African grassroots football context.
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The changing nature of work: understanding precarity and the gendered individualisation of risk in post-apartheid South Africa
- Authors: Mhlana, Siviwe
- Date: 2021
- Subjects: Precarious employment , Labor supply -- South Africa , Labor supply -- Statistics -- South Africa , Precarious employment -- South Africa , Informal sector (Economics) -- Employees -- South Africa , Women employees -- South Africa , Women temporary employees -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172146 , vital:42170
- Description: Against the backdrop of workplace restructuring globally, post-Apartheid South Africa is experiencing consistently high levels of unemployment, the deterioration of employment security, and limited improvements in earnings. This trend in the proliferation of low-paid, unstable and otherwise insecure employment has given rise to a segment of the literature that is centred on the growing precariousness of work in a number of different contexts. This thesis reviews empirical work on the changing nature of labour-intensive production in the past two decades, with particular focus on the trends in non-standard, informal and precarious employment. Further, the thesis examines the shift in the gender structure of South Africa’s manufacturing sector and how it affects the share in the benefits of employment, particularly with regard to social reproduction. In so doing, the thesis expands the critical theoretical narrative about the challenges of labour under neoliberalism by providing an intersectional perspective of precarious work in post- Apartheid South Africa.
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The effect of habitat and spatial management on reef fish in an established marine protected area
- Authors: Dames, Vivienne Abigail
- Date: 2021
- Subjects: iSimangaliso Wetland Park (South Africa) -- Management , Reef fishes -- South Africa -- KwaZulu-Natal , Baited remote underwater stereo-video systems (stereo-BRUVs) , Marine parks and reserves -- Monitoring -- South Africa -- KwaZulu-Natal , Fish populations -- Measurement
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171150 , vital:42024
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
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The electrocatalytic response of metallophthalocyanines when clicked to electrodes and to nanomaterials
- Authors: Mpeta, Lekhetho Simon
- Date: 2021
- Subjects: Phthalocyanines , Nanostructured materials , Electrocatalysis , Nanoparticles , Environmental chemistry , Electrodes , Organic wastes -- Purification
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172191 , vital:42174 , 10.21504/10962/172191
- Description: Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed.
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The impact of labour legislation on selected small firms in Mbombela (Nelspruit)
- Authors: Dlamini, Sikhulile Blessing
- Date: 2021
- Subjects: Labor laws and legislation -- South Africa , Small business -- Law and legislation-- South Afric , Small business -- South Africa -- Mbombela -- Case studies
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: http://hdl.handle.net/10962/170781 , vital:41959
- Description: This study uses the theoretical framework of industrial relations pluralism, to study and analyse the impacts of labour legislation on six small firms (employing less than 50 workers) based in Mbombela (formerly Nelspruit), Mpumalanga province, South Africa. The analysis is based on the viewpoints of six managers and how they see the impacts of labour legislation on their respective firms. The analysis is aided by utilising theory and literature to make sense of the manager perspectives on the topic. Also, utilising a qualitative research design to collect and analyse the data, the study presents diverse findings in terms of how the participants perceived and experienced certain types of legislation. Some managers believed that the benefits of labour legislation outweighed the costs. While others believed the exact opposite. At an overall level, the study revealed that most of the participants were not as severely affected by labour legislation as might be expected; given the scarcity of resources in most small firms. This was partly because of various coping strategies and practices (mostly involving the use of informal procedures) that were adopted by the firms. Also, some small firms who aimed at expanding their businesses strategised to adopt some formal procedures and practices in order to easily absorb labour legislation and subsequently mordenise their businesses in the process. While a few firms persisted with more informal customs as they appeared cost-effective and necessary in their particular market positioning.
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The invasion ecology of Pontederia cordata L. (Pontederiaceae) in South Africa
- Authors: Wansell, Sage Nora-Lee
- Date: 2021
- Subjects: Plant invsions -- South AFrica , Invasive plants -- Ecology -- South Africa , Pontederiaceae -- South AFrica
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172433 , vital:42200
- Description: Pontederia cordata L. (Pontederiaceae) is a tristylous invasive macrophyte – originating from North and South America – that has caused detrimental environmental, agricultural and socio-economic impacts in South Africa (SA). This novel study investigates the invasive ecology of P. cordata in SA by determining population genetics, pollination ecology and floral traits. Preliminary field surveys suggest that only one of three tristylous forms of P. cordata is invading SA and no seeds have been observed in any invasive populations. This study therefore determined the population genetics, mode of spread of P. cordata in SA and possible reasons for the lack of seed production, as well as providing suggestions for future control and management strategies. Inter Simple Sequence Repeats of leaf samples from invasive populations in SA and the native range of the United States of America (USA) were performed to determine the population genetics of P. cordata. The clarification of population structure of an alien invasive plant can provide insight into founder effects, introduction events and modes of spread and is important for the development of management plans such as biological control. Results from the genetic analyses indicated that P. cordata populations have low genetic diversity within and amongst invasive populations in comparison to native populations. This suggests that high gene flow and sexual reproduction is not present in invasive populations, and that only a single or very few introductory events have occurred in SA. Furthermore, invasive P. cordata populations shared the highest genetic similarity with native samples from Belle Haven, Virginia, USA, and thus further sampling and future genetic surveys should be conducted in this area to identify source populations to survey for potential biological control agents. Following these findings, I investigated whether sexual reproduction and seed production is absent from invasive P. cordata populations in SA as speculated. Floral traits from populations throughout all the invaded provinces were measured and, along with pollen grain measurements, it was determined that only short-morphed plants are present in SA. It was speculated that the absence of native pollinators in the invasive range may be responsible for the absence of sexual reproduction. However, a pollination study confirmed the presence of generalist insect pollinators. Thereafter, artificial pollination experiments on 8 865 flowers were conducted to determine whether an incompatibility system was present which prevented seed production. No seeds were produced and it was concluded that illegitimate pollination of the short-morphed plants prevented seed production and rhizomes are responsible for the invasion of P. cordata throughout SA. The implications of these findings and possible management strategies such as biological control is discussed in Chapter 4. These findings suggest that control programmes should target the plants rhizomes to prevent and reduce spread. Preventing the introduction of medium- and long-morphed plants into SA is crucial to prevent P. cordata from producing seeds and intensifying invasion further through both asexual and sexual spread.
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The potential conflict of interest associated with the management of Rosa rubiginos L. (Rosehip) in South Africa
- Authors: Westwood, Timothy
- Date: 2021
- Subjects: Invasive plants -- South Africa , Biological invasions -- Economic aspects , Rose hips -- Economic aspects -- South Africa , Roses -- South Africa , Rose culture -- Economic aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172458 , vital:42204
- Description: Rosa rubiginosa L. is a category 1b invasive plant species in South Africa and must be controlled according to NEM:BA. However, R. rubiginosa has the potential to provide economic benefit in South Africa due to the expanding market for the shrubs fruit, rosehips. The shrub is not permitted to be cultivated in South Africa due to legislation, limiting the economic potential as the rosehips are only able to be collected from wild R. rubiginosa shrubs. In order to expand the rosehip market in South Africa a downgrade or removal of R. rubiginosa from the invasive species list would be required, as wild harvest is limited. This study aims to assess the benefits and cost associated with R. rubiginosa in order to determine whether the legislation should be altered allowing for the cultivation of the shrub in South Africa. Due to the limited literature surrounding R. rubiginosa three different questionnaires and a case study were used in order to assess the benefits and negatives associated with the shrub. Experts in the field of invasion biology were surveyed to bridge the gap in the R. rubiginosa literature. Landowners, where the shrub is abundant, were surveyed to determine the negative impacts of R. rubiginosa. Rosehip companies were surveyed in order to determine the current size and potential of the R. rubiginosa (rosehip) market. The case study looked at how a rosehip company would benefit if R. rubiginosa was allowed to be cultivated in South Africa. The study found R. rubiginosa to have great economic potential and market growth, with very little negative economic impact. The case study showed that one rosehip company would grow from 1500 tons of raw rosehip to 20 000 tons if cultivation was allowed, resulting in a growth in turnover from R57 million to R760 million ($1=R14.8). The findings in the study show that R. rubiginosa does not significantly affect landowners where it is abundant. Therefore, it is suggested that a change to the legislation should be considered allowing for the cultivation of R. rubiginosa should be implemented.
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Towards the development of a pro-environmental strategy for improving catch-and-release behaviour in recreational fisheries – a case study on a competitive South African angling body
- Authors: Mannheim, Samantha L
- Date: 2021
- Subjects: Fishing -- Environmental aspects -- South Africa , Fishing -- South Africa , Fishers -- Attitudes -- South Africa , Fishers -- Attitudes -- South Africa -- Cast studies , Fishes -- Conservation -- South Africa , Rock and Surf Super Pro League , Southern African Fisheries Ecology Research Lab
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171862 , vital:42133
- Description: Catch-and-release (C&R) is becoming increasingly popular in recreational fisheries with the potential to contribute towards conserving the oceans limited fish stocks. Several studies have highlighted high rates of mortality and many sub-lethal effects which ultimately have a negative impact on fish population viability. With poorly developed handling practices, the fish that are released suffer the consequences of physical and physiological stress and do not always survive, thus making the ethics of C&R fishing questionable. Many studies have contributed to our understanding of the factors that influence the fate of fish released by anglers. Despite this, few interventions have been able to improve angler C&R behaviour. Pro-environmental behavioural strategies however hold some potential for improving angler C&R behaviour. To test their potential, we partnered with the South African Rock and Surf Super Pro League (RASSPL Africa), the biggest exclusively C&R competitive shore-based angling league in South Africa. The first two years (2013 and 2014) of the partnership were purely focused on building trust and relationships and making observations on angler behaviour. In 2015, we collected baseline data on angler behaviour and fish health during the RASSPL national fishing competition. This was followed by comparable data collection at the following two national competitions in 2016 and 2017 after the introduction of a combination of pro- environmental behaviour interventions, including rule changes, improving angler knowledge, behavioural modelling, rewards, penalties and feedback to improve C&R behaviour. There were significant improvements in angler behaviour, including a decline in total air exposure from 101.93s ± 64.34 in 2015 to 77.37s ± 60.52 in 2017 (F(2,618) = 9.27, P < 0.01), and the time taken for an angler to place their fish into a bucket declined from 105.86s ± 69.47 in 2015 to 23.05s ± 24.13 in 2017 (F(2,556) = 158.71, P < 0.01). There were also improvements in the health of the fish, with a decline in the blood lactate concentration and mean reflex action mortality predictor (RAMP’s) scores for the dominant species, Diplodus capensis (lactate – 9.46 ± 3.80 mmol.l-1 in 2015 and 6.69 ± 2.99 mmol.l-1 in 2017, RAMP – 0.28 ± 0.22 in 2015 and 0.19 ± 0.17 in 2017), and Haploblapharus fuscus (lactate – 4.25 ± 1.89 mmol.l-1 in 2015 and 1.76 ± 0.78 mmol.l-1in 2017, RAMP – 0.15 ± 0.18 in 2015 and 0 ± 0 in 2017). In 2018, surveys were conducted to gain insight into angler demographics and external (social, economic, cultural and institutional) and internal factors (knowledge and awareness, motivations, attitudes and perceptions) associated with the RASSPL anglers. Surveys were also designed to assist in identifying what components were key drivers behind the angler’s behavioural changes. The demographic characteristics of RASSPL anglers were not dissimilar from the general recreational angling public in South Africa, suggesting that this kind of intervention may have potential at a broader scale. In terms of the drivers of behavioural change, the surveys revealed that 68% of respondents strongly agreed that the structural rule changes contributed to their improved behaviour. This was followed by the educational presentations (66% of the respondents) and modelling / demonstrative videos (59% of the respondents). The conservation prizes were considered less effective, with only 27% of anglers strongly agreeing that this intervention improved their C&R behaviour. Overall this study has demonstrated that it is possible to improve the C&R behaviour of anglers in a competitive setting, with the most effective component of the intervention being the use of rule changes (structural approach). These findings suggest that proenvironmental strategies hold potential for improving the C&R behaviour of anglers and the health of released fishes. It is suggested that interventions to improve C&R behaviour should aim to develop long-term relationships, and implement a broad range of well communicated strategies based on reliable data and sound rationality. Key words: marine shore-based fisheries; community engagement; pro- environmental behaviour; behavioural intervention.
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“Munhu wese ihama yako (everyone is your relative)”: Ubuntu and the social inclusion of students with disabilities at South African universities
- Authors: Chiwandire, Desire
- Date: 2021
- Subjects: College students with disabilities -- Education -- South Africa , Inclusive education -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170578 , vital:41938 , 10.21504/10962/170578
- Description: Background: During apartheid, South African students with disabilities (SWDs) were educated in special schools and taught an inferior curriculum. Black learners with disabilities were discriminated against on grounds of both race and disability. Following South Africa’s first democratic election in 1994, the African National Congress (ANC) government put in place arrange of new laws to address the educational and other needs of those disadvantaged under apartheid, including persons with disabilities (PWDs). The South African government is a signatory of the 2006 United Nations Convention on the Rights of Persons with Disabilities (UNCRPD) which has resulted in the country assuming obligations to promote inclusive education for ASWDs. However, research (see, for instance, Chiwandire & Vincent 2019; Chiwandire 2019; Mutanga 2019; Majoko & Phasha 2018; Mutanga et al. 2018; Mutanga 2017a; Chiwandire 2017; Israel 2017) has shown that SWDs continue to fare differently in comparison to their non-disabled peers in terms of participation in education with the likelihood of success. Higher education institutions (HEIs) have thus been urged to create conducive environments for the academic inclusion of SWDs with particular attention being paid to lecturers employing inclusive instructional strategies as well as flexible curricula, if they are to ensure the equal opportunity for academic success of SWDs in the regular classroom setting. The focus, to date, on academic inclusion, while important, has meant that issues relating to the social inclusion of SWDs have received minimal attention. Purpose: To date, there is a dearth of South African studies which have investigated the social inclusion needs of SWDs on South African campuses. Although a number of studies have given voice to the perspectives of SWDs and lecturers, with respect to their experiences in relation to matters of academic inclusion in South African higher education (HE), few have focused on Disability Unit Staff Members(DUSMs) who are pivotal to ensuring fair and equitable policies and practices for SWDs in HEIs. Disability Studies (DS) as a field has been criticised for being dominated by voices from the Global North, which fail to consider or effectively theorise Global South disability experiences in a contextually relevant way. The thesis argues that the failure to recognise the value of diversity and to treat SWDs as valued and welcomed participants in South African HEIs partly stems from policy, practice and relationships being informed by the Western individualist paradigm that prizes individual achievement and success rather than cooperation and mutuality. The African philosophy of Ubuntu, which stresses values of communalism, hospitality and respect for human dignity is offered here as an alternative starting point for achieving genuinely inclusive campuses. Methods: In-depth face-to-face qualitative interviews were conducted with 40 participants, most of whom were, at the time of being interviewed, Heads of Disability Units and DUSMs based at 10 different universities in four of South Africa’s nine provinces. Data were coded and analysed using Braun & Clarke’s (2006) method of inductive and deductive thematic analysis. Results: The findings of this study indicate that South African campuses are ableist spaces in which the social needs of SWDs are not prioritised. The thesis argues that in order for campuses to become genuinely inclusive, South African campuses ought to seek to inculcate in their members the values of the African worldview Ubuntu, in contrast to the dominant Western individualist orthodoxy. SWDs are being excluded and denied a sense of belonging and equal participation despite universities giving lip service to embracing such inclusive education-oriented values as co-operative learning. Non-disabled students steeped in Western individualism, which affirms the solitary pursuit of individual success rather than the value of interdependence and diversity, end up marginalising SWDs who are seen as less capable. DUSMs addressing the needs of SWDs through an ableist/Western individualist lens are not challenging unfair practices which are impairing the dignity of SWDs, particularly students with physical disabilities who are being forced to “fit into” oppressive inaccessible built environments on campuses. These DUSMs may unwittingly re-inscribe ableist assumptions that normalise discrimination against SWDs. Conclusions and Recommendations: Ubuntu values offer a starting point for building mutual respect and interdependence between SWDs and their non-disabled peers. The thesis finds however that as was the case in traditional African communities, which embraced the values of Ubuntu, acts of leadership are required if Ubuntu’s values of human dignity, mutual respect and acceptance are to be fostered on campuses. In a range of important ways, the dignity of SWDs is not respected at HEIs in South Africa. This includes, for example, such practical matters as the inaccessibility of toilets to wheelchair users and the lack of appropriate signage for blind students. Disrespectful attitudes and assumptions about SWDs on the part of non-disabled university members also result in SWDs’ human dignity being impaired. Ubuntu’s value of hospitality stresses the importance of promoting relations of group solidarity and interdependence between SWDs and their non-disabled peers. Both academic inclusion-oriented programmes and the promotion of a wide range of social activities, involving both SWDs and non-disabled students, can play an important role in cultivating the formation of long-term fruitful and respectful friendships between SWDs and non-disabled students. An enabling classroom environment alone is not enough to holistically address the social inclusion needs of SWDs. South African HEIs that embrace the Ubuntu values of communalism, human dignity and hospitality will be in a position to respect the needs of SWDs as “whole persons”. Amongst other things, this requires DUSMs to be fully empowered to make important decisions regarding vital matters such as disability inclusion, and it necessitates university management to relinquish their power, so that they may work collaboratively with DUSMs and SWDs, all on equal footing, to ensure that HE funding allocation, policy and planning also prioritises the social needs of SWDs.
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A drug utilisation review of lithium at a public sector psychiatric hospital
- Authors: Mapfumo, Charlotte
- Date: 2020-04
- Subjects: Lithium -- Therapeutic use , Psychiatric hospitals -- South Africa -- Grahamstown , Drug utilization , Psychiatric hospital care , Manic-depressive illness , Lithium -- Toxicology , Drug monitoring
- Language: English
- Type: text , Thesis , Masters , M.Pharm
- Identifier: http://hdl.handle.net/10962/150541 , vital:38983
- Description: Bipolar disorder (BD) is a common mental condition that affects about 60 million people globally. Lithium is among the drugs of choice used to treat BD and other affective disorders such as schizoaffective disorder (SD). Lithium is a mood stabiliser with antimanic, antidepressant and anti-suicidal properties. Lithium has complex mechanisms of action and a narrow therapeutic index (NTI). Therapeutic drug monitoring (TDM) is a vital component of lithium therapy due to its NTI. Lithium toxicity can occur at therapeutic levels and is characterised by symptoms such as blurred vision and convulsions. Lithium interacts with a number of drugs resulting in lithium toxicity or diminished effects of lithium. Symptoms of lithium toxicity range from abdominal pain, convulsions and death. Lithium use is associated with serious adverse effects on renal and thyroid function. Other adverse effects include tremor and weight gain. Monitoring of lithium serum levels, renal and thyroid function are therefore recommended for patients on lithium therapy. Monitoring of these parameters assists in the early detection of any problems associated with lithium use. The metabolic monitoring of lithium is vital due to the adverse effect profile of lithium and the current South African Standard Treatment Guidelines Hospital level: Adults, do not have any recommendations for the monitoring of metabolic parameters. The National Institute for Health and Care Excellence (NICE) may be used and adapted for the South African setting. Aim and Objectives: The general aim of the study was to conduct a drug utilisation review (DUR) on lithium through investigating its prescribing and monitoring patterns in both inpatients and outpatients at Fort England Hospital. Methodology: The study was in the form of a retrospective DUR. Data was collected from 40 files (n=40) of patients who were on treatment with lithium between 1 January 2017-31 December 2017 at Fort England Hospital. The data was collected retrospectively for both in- and outpatients. Compliance of the monitoring requirements with both South African and international guidelines was analysed. Results and Discussion: In 87.50% (n=37) of the cases, patients had been on lithium therapy before 2017 with most patients (n=13; 37.50%) being maintained on 500 mg of lithium. Non-compliance with the South African and NICE guidelines for renal baseline monitoring was 65.00% (n=26) in both guidelines. Non-compliance for baseline thyroid monitoring was 70.00% (n=28) for both guidelines. There was non-compliance in 45.00% (n=18) of the cases for lithium serum level monitoring for both guidelines. Non-compliance with follow-up renal monitoring was 47.50% (n=19) for both guidelines. Compliance with the NICE guidelines for follow-up metabolic monitoring was 67.50% (n=27). Conclusion: There was non-compliance in most cases leaving room for clinical improvement in the monitoring of lithium. Healthcare professionals should be educated on the recommended monitoring guidelines to promote the rational use of lithium in South Africa. Pharmacists should be more involved in the TDM of lithium to promote its safe and effective use.
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Application of quality by design to the manufacture of a multiparticulate prednisone dosage form
- Authors: Manda, Arthur
- Date: 2020-04
- Subjects: Drugs -- Quality control , Drugs -- Design -- Quality control , Drugs -- Dosage forms , Drug development -- Quality control , Pharmaceutical industry -- Quality control , Prednisone , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Masters , MSc (Pharmacy)
- Identifier: http://hdl.handle.net/10962/117986 , vital:34583
- Description: For many years, quality by testing was the only approach to guarantee quality of drug products before the Food and Drug Administration launched the concept of current Good Manufacturing Practice. In order to gain more knowledge of the manufacturing process, a new system known as Quality by Design was introduced into the pharmaceutical industry. Quality by Design is based on thorough understanding of how materials, process parameters and interaction thereof impact final product quality. Quality by Design is a systematic approach to product development which ensures that quality is built into a product during product development and not just tested into it. The aim of Quality by Design is to achieve optimum product quality with consistent dosage form performance and minimal risk of failure in patients. The objective of these studies was to implement a Quality by Design approach to establish a design space for the development and manufacture of a safe, effective and stable multi-partite solid oral dosage form for prednisone as an alternative to currently marketed prednisone formulations. Multi-particulate dosage forms offer significant advantages over conventional technologies. In addition to lowering the incidence of gastrointestinal irritation they exhibit a reduced risk of dose dumping and a large surface area which favours dissolution. Furthermore, their free flowing nature facilitates reproducible capsule filling and consequently uniformity of dosing. Different multi-particulate dosage forms exist however a multiple-unit pellet system was investigated during these studies. Quality by Design principles were used to develop and establish a reversed-phase high performance liquid chromatographic method for quantifying prednisone from solid oral dosage forms. A Central Composite Design was used to generate multivariate experiments and to investigate the impact of input variables on the quality and performance of the analytical method. The optimized method was validated according to International Council for Harmonization guidelines and was found to be linear, precise, accurate and specific for the quantitation of prednisone. Pre-formulation studies were conducted and included the assessment of particle size, particle shape, powder flow properties and compatibility studies. Carr’s index, Hausner ratio and the Angle of Repose were used to evaluate powder flow properties and results generated from all studies suggest the need for adding a glidant and lubricant to improve pellet flow. The images generated from Scanning Electron Microscopy were used to analyze particle shape and size. Differential Scanning Calorimetry and Fourier Transform Infrared Spectroscopy were used to evaluate API-excipient compatibility. All excipients investigated were found to be compatible with prednisone and suitable for formulation development studies. Extrusion-spheronization was used to manufacture prednisone pellets. Extrusion-spheronization is a multi-step process involving many factors. Quality risk management tools particularly an Ishikawa Fishbone (cause and effect) diagram and failure mode and effects analysis were used to narrow down potentially significant factors to a reasonable number that could be investigated experimentally. Risk priority numbers were used to quantify risk and factors above a set threshold value were considered to be of high risk. A total of eleven risk factors were identified as high. A Plackett-Burman study was conducted to narrow down the eleven high risk factors to identify the most impactful factors viz., microcrystalline cellulose content, sodium starch glycolate content, extrusion speed and spheronization time. Evaluation of four factors was carried over to optimization studies using a Box-Behnken Design and following identifaction of the optimum process settings and excipient content a design space for the manufacture of a multi-partite dosage form containing prednisone was established.
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Evaluating the prescribing and management practices of clozapine at a public sector psychiatric hospital
- Authors: Mukoko, Vimbisai Millicent
- Date: 2020-04
- Subjects: Clozapine , Schizophrenia -- Chemotherapy , Schizophrenia -- South Africa -- Treatment
- Language: English
- Type: text , Thesis , Masters , M.Pharm
- Identifier: http://hdl.handle.net/10962/123266 , vital:35422
- Description: Approximately one percent (1%) of the South African population suffers from schizophrenia. Clozapine has proven to be more effective than conventional antipsychotics in the treatment of schizophrenia, particularly in alleviating positive symptoms. Clozapine is primarily indicated for treatment-resistant schizophrenia due to its severe adverse effect profile. The prescribing guidelines recommend a trial of at least two different antipsychotic drugs before the initiation of clozapine. At least one should be a non-clozapine second generation antipsychotic. Compared to other atypical antipsychotics, clozapine poses the greatest risk of causing a haematological event, such as neutropenia and agranulocytosis. Agranulocytosis (estimated prevalence of 1.3%) is a life-threatening adverse effect. Common adverse effects include weight gain and metabolic syndrome, hypersalivation and constipation. These can also predispose the patient to co-morbid diseases which further complicate their current diagnosis. Haematological and metabolic monitoring is paramount throughout the duration of clozapine therapy. International (NICE guidelines, Clozapine REMS, and Maudsley prescribing guidelines) and national (South African STGs, SASOP treatment guidelines and the SAMF) guidelines recommend these monitoring patterns to assist with the prevention and management of the adverse effects of clozapine.
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Evaluating the prescribing and management practices of venlafaxine at a public sector psychiatric hospital
- Authors: Naidu, Bavika
- Date: 2020-04
- Subjects: Venlafaxine , Anxiety disorcers -- Treatment , Depression, Mental -- Treatment
- Language: English
- Type: text , Thesis , Masters , M.Pharm
- Identifier: http://hdl.handle.net/10962/123200 , vital:35414
- Description: Neuropsychiatric conditions have been ranked third in South Africa according to some of the most recent reviews of disease burden, following human immunodeficiency virus/acquired immune deficiency syndrome and other infectious diseases (Bateman, 2012:70; South African Depression and Anxiety Group, 2018). For depressive disorders, the conventional selective serotonin reuptake inhibitors (e.g. fluoxetine), are common first-step treatments due to their relatively low toxicity and high tolerability (Rush et al., 2006:1231). The class of selective noradrenaline reuptake inhibitors (e.g. venlafaxine) is relatively new on the market. The first SNRI to be marketed in the United States was venlafaxine immediate-release (IR). It was approved by the United States FDA in 1993 (Sansone and Sansone, 2014:37) and was soon followed by the introduction of a micro-encapsulated extended-release (XR) formulation in 1997. Currently there is no published or readily available information concerning the prescribing and management patterns of venlafaxine as well as the incidence and types of adverse effects experienced by patients in the public health sector of South Africa besides the established increased in blood pressure.
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300 grams
- Authors: Ainslie, Michelle
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140597 , vital:37903
- Description: This document consists of two (2) parts:Part A: Thesis (Creative Work)Part B: Portfolio.
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A 150 MHz all sky survey with the Precision Array to Probe the Epoch of Reionization
- Authors: Chege, James Kariuki
- Date: 2020
- Subjects: Epoch of reionization -- Research , Astronomy -- Observations , Radio interferometers
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/117733 , vital:34556
- Description: The Precision Array to Probe the Epoch of Reionization (PAPER) was built to measure the redshifted 21 cm line of hydrogen from cosmic reionization. Such low frequency observations promise to be the best means of understanding the cosmic dawn; when the first galaxies in the universe formed, and also the Epoch of Reionization; when the intergalactic medium changed from neutral to ionized. The major challenges to these observations is the presence of astrophysical foregrounds that are much brighter than the cosmological signal. Here, I present an all-sky survey at 150 MHz obtained from the analysis of 300 hours of PAPER observations. Particular focus is given to the calibration and imaging techniques that need to deal with the wide field of view of a non-tracking instrument. The survey covers ~ 7000 square degrees of the southern sky. From a sky area of 4400 square degrees out of the total survey area, I extract a catalogue of sources brighter than 4 Jy whose accuracy was tested against the published GLEAM catalogue, leading to a fractional difference rms better than 20%. The catalogue provides an all-sky accurate model of the extragalactic foreground to be used for the calibration of future Epoch of Reionization observations and to be subtracted from the PAPER observations themselves in order to mitigate the foreground contamination.
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