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Non-material costs of wildlife conservation to local people and their implications for conservation interventions:

  • Authors: Thondhlana, Gladman , Redpath, Stephen Mark , Vedeld, Pål Olav , van Eden, Lily , Pascual, Unai , Sherren, Kate , Murata, Chenai
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/150174 , vital:38946 , https://doi.org/10.1016/j.biocon.2020.108578
  • Description: In assessment of costs (and benefits) of wildlife conservation, conventional economic valuation frameworks may inadequately address various non-tangible values and neglect social, cultural and political contexts of resources and their use. Correspondingly, there seems to be much more focus on quantifying the economic, material benefits and costs of wildlife conservation than the non-material aspects that also affect human well-being. In addition, current research on the costs of wildlife conservation tends to be discipline-focused which constrains comparability, often causing conceptual ambiguity. This paper is an attempt to address this ambiguity. While there is growing acknowledgement of the material costs of wildlife conservation, we contend that employing a broader, composite social well-being approach may provide better conceptual insights on—and practical options for—managing various non-material impacts of wildlife conservation for local people.
  • Full Text:
  • Date Issued: 2020

Plant Fibre Crafts Production, Trade and Income in Eswatini, Malawi and Zimbabwe

  • Authors: Thondhlana, Gladman , Pullanikkatil, Deepa , Shackleton, Charlie M
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/175936 , vital:42642 , https://doi.org/10.3390/f11080832 , https://doi.org/10.21504/RUR.c.5388470.v1
  • Description: The production of plant fibre products is considered a promising pathway for contributing to people’s livelihoods particularly in developing countries, where economic options might be limited. However, there are limited comparative studies across countries on plant fibre products, making it difficult to examine how local and broader biophysical, socioeconomic, cultural and policy contexts influence craft production patterns in terms of primary plant resources used, products made and contributions to livelihoods. Using household surveys for data collection, this paper presents findings from a comparative analysis of plant fibre craft production and income in three southern African countries, Eswatini, Malawi and Zimbabwe.
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  • Date Issued: 2020

Effects of high-intensity speed training on the speed reserve of university middle-distance and field sport athletes

  • Authors: Thomas, Emma Jayne
  • Date: 2020
  • Subjects: Athletes
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10948/46346 , vital:39599
  • Description: Context: Despite the multiple differences between athletic events and sports, they all share the sporadic bouts of moderate to extreme intensities and all require some contribution from an integrated bioenergetic system to allow for optimal performance. Although D’ is often considered as an ‘anaerobic work capacity’, such a definition is over-simplistic and its precise composition is nebulous, especially given the mixed findings of the experimental evidence. Clearly, further research is needed to provide a more complete understanding of the D’ parameter, as well as the speed reserve(range of speeds exceeding critical speed) especially within high-intensity exercise. Purpose (Aim): The aim of this study is to determine whether a short term high-intensity speed training intervention within the severe intensity domain effects speed reserve in athletic and non-athletic individuals considered moderately trained.Methods: A quantitative research design was used. Participantscompletedbaseline testing (pre-test), after which they were assigned into two groups. Both groups received a HIIT training program, with group 1 (G140%) receiving a program based on intensity prescription (work bouts performed at 140% of CS)and group 2 (G90-s) receiving a program based on time intervals (work bouts performed for 90-s). HIIT sessions were performed twice-weekly for a total of 6-weeks. A post-test assessment was then conducted by both groups to determine whether any changes have accrued in any of the physiological variables in question. Participants of the study met a specific criterion(18 –30 years of age, residing in Nelson Mandela Bay, and met the minimum fitness requirements). Results: No significant between-group differences were evident prior to and following cessation of the HIIT intervention. Findings that can be highlighted holistically include improvements in CS(G140%: M = 0.62 m.s-1; G90-s: M = 0.46 m.s-1)and 𝑉̇𝑂2𝑚𝑎𝑥 (G140%: +3.81 ml.kg-1.min-1; G90-s: +5.19 ml.kg-1.min-1)and a decrease in fatigue index (G140%: M = -6.75%; G90-s: M = -4.38%) and D’(G140%: M = -56.34 m; G90-s: M = -18.36 m).Normative data were generated for athletic and non-athletic participants using the standard nine (Stanine) categorization to facilitate interpretation and recommendations of key parameters for coaches and clinicians. Moreover, a deterministic model was also generated which revealed novel interactions and the strength of the relationship between variables-potentially opening new and innovative areas of future research. Conclusions: The interval durations and speeds utilised in the present study were insufficient to stimulate an increase in D’. To elicit an increase of D’, one would have to decrease the duration of the intervals performed(i.e. < 90-sec), while increasing speed at which the intervals performed at some speed greater than 140% of CS, but below MSS. Further research is needed to understand the physiological underpinning of the D’ parameter both in isolation and in conjunction with CS. It is clear that D’ is influenced by parameters such as MSS, 𝜏d and FI%; therefore, these sub-parameters should be explored further as potentiators for moderating the D’ parameter.
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  • Date Issued: 2020

A comparative mineralogical and geochemical study of manganese deposits in the Postmasburg Manganese Field, South Africa

  • Authors: Thokoa, Mamello
  • Date: 2020
  • Subjects: Manganese ores -- South Africa -- Postmasburg , Geology -- South Africa -- Postmasburg
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/167609 , vital:41496
  • Description: The Postmasburg Manganese Field (PMF), located in the Northern Cape Province of South Africa, is host to some of the largest deposits of iron and manganese metal in the world. These deposits are restricted to a geographical area known as the Maremane Dome, an anticlinal structure defined by folded dolostones of the Campbellrand Subgroup and overlying ironformations of the Asbestos Hills Subgroup of the Neoarchaean-Palaeproterozoic Transvaal Supergroup. Manganese ores associated with the Maremane Dome have been divided into two major classes in the literature: the Wolhaarkop breccia-hosted massive ores of the Eastern Belt, as well as the shale-associated ores of the Western Belt. The Eastern Belt ores have been classed as siliceous in nature, while the Western Belt deposits are reported to be typically ferruginous. These divisions were made based on their varying bulk chemical and mineralogical compositions in conjunction with their different stratigraphic sub-settings. Presently, both deposit types are explained as variants of supergene mineralisation that would have formed through a combination of intense ancient lateritic weathering in the presence of oxygen, extreme residual enrichments in Mn (and Fe), and accumulations in karstic depressions at the expense of underlying manganiferous dolostones. This study revisits these deposits and their origins by sampling representative end-member examples of both Eastern Belt and Western Belt manganese ores in both drillcore (localities Khumani, McCarthy and Leeuwfontein), and outcrop sections (locality Bishop). In an attempt to provide new insights into the processes responsible for the genesis of these deposits, the possibility of hydrothermal influences and associated metasomatic replacement processes is explored in this thesis. This was achieved using standard petrographic and mineralogical techniques (transmitted and reflected light microscopy, XRD , SEM-EDS and EMPA), coupled with bulk-rock geochemical analysis of the same samples using a combination of XRF and LAICP- MS analyses. Combination of field observations, petrographic and mineralogical results, and geochemical data allowed for the re-assessment of the different ore types encountered in the field. Comparative considerations made between the bulk geochemistry of the different end-member ore types revealed no clear-cut compositional distinctions and therefore do not support existing classifications between siliceous (Eastern Belt) and ferruginous (Western Belt) ores. This is supported by trace and REE element data as well, when normalised against average shale. The geochemistry reflects the bulk mineralogy of the ores which is broadly comparable, whereby braunite and hematite appear to be dominant co-existing minerals in both Eastern Belt (Khumani) and Western Belt (Bishop) ore. In the case of the McCarthy locality, manganese ore is cryptomelane-rich and appears to have involved recent supergene overprint over Eastern Belt type ore, whereas the Leeuwfontein ores are far more ferruginous than at any other locality studied and therefore represent a more complex, hybrid type of oxide-rich Mn mineralisation (mainly bixbyitic) within massive hematite iron ore. In terms of gangue mineralogy, the ores share some close similarities through the omnipresence of barite, and the abundance of alkalirich silicate minerals. Eastern Belt ores contain abundant albite and serandite whereas the main alkali-rich phase in Western Belt ores is the mineral ephesite. In both cases, Na contents are therefore high at several wt% levels registered in selected samples. The afore-mentioned alkali enrichments have been variously reported for both these deposit types. The occurrence of high alkalis cannot be explained through classic residual or aqueous supergene systems of ore formation, as proposed in prevailing genetic models in the literature. Together with the detection of halogens such as F and Br through SEM-EDS analyses of ore from both belts, the alkali enrichments suggest possible hydrothermal processes of ore formation involving circulation of metalliferous sodic brines. Selected textural evidence from samples from both ore belts lends support to fluid-related models and allow the proposal for a common hydrothermal-replacement model to have been responsible for ore formation across the broader Maremane Dome region.
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  • Date Issued: 2020

A study on certain factors that may affect the economic viability of backgrounding beef weaner calves on pastures in the Southern Cape area of South Africa

  • Authors: Terblanche, Ian
  • Date: 2020
  • Subjects: Calves -- Weaning -- South Africa
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: http://hdl.handle.net/10948/47623 , vital:40259
  • Description: The backgrounding of beef weaner calves from pastures has the potential to be developed as an intensive beef enterprise that can increase the income of smaller farms, given that these farms have the ability to produce good quality pastures. This study was conducted to verify the inputs that impact on the viability of pasture backgrounding systems in an attempt to provide beef producers with better information for decision making. The scientific research was conducted with the registered Kromme Rhee Bonsmara herd at the Kromme Rhee research farm of the Western Cape Department of Agriculture. The farm is situated at 18º50’E and 33º51’S in the Stellenbosch area and has an altitude of 177 m above sea level. The area is situated in the winter rainfall region of the Western Cape with an annual rainfall of 670 mm. The average summer temperature ranges between 15-35 ºC and winter temperature between 10-17 ºC. The aim of this study was to develop growth curves representing the growth of Bonsmara animals for use by beef producers in predicting future live weight of animals in a pasture backgrounding system. Dry matter (DM) intake was measured at various live weight stages in order to determine whether a prediction model could be established to represent the DM intake of growing Bonsmara cattle on pastures. Results were used as inputs to determine whether backgrounding on pastures was economically viable. Animals were weighed at monthly intervals. Weighings commenced from birth and continued for a period of 797 days, repeated with two production year groups. One group consisted of 18 heifers and 12 bulls that were weighed from birth till an average age of 759 days. The other group consisted of four heifers and seven bulls and was weighed from birth untill an average age of 892 days. Roughage supplementation was done with lucerne hay in periods of pasture shortfalls, while a protein and energy lick were supplied continuously. A feeding trial with 10 weaned heifers and 10 bull calves of the same year group was conducted to determine the average feed intake per individual animal over a thirteen-month period that commenced after weaning. Two groups of five Bonsmara bull calves and two groups of five Bonsmara heifers were grouped according to age and gender. The feed intake of the growing calves was recorded for different live weight categories. The animals received lucerne (Medicago sativa) hay on an ad lib basis, while a concentrate supplement was supplied at 2 kg per animal per day up until live weights of 350 kg for heifers and 380 kg for bulls was achieved. The lucerne based diet was formulated to simulate a diet for growing animals on pasture with additional supplementation. Group feed intake values of the four groups of animals were measured at about 20-day intervals over the trial period of 369 days. The feed waste was dried and weighed back to calculate a waste percentage to be used as a correction factor. The Gompertz growth function was used to develop growth curves for male and female Bonsmara animals. Results indicated a significant difference between the mature weight of males and females (P <0.05). In both year groups the nonlinear Gompertz growth model predicted heavier mature weight for males compared to females. Mature weights of bulls were respectively 44.4% and 68.5% higher than that of heifers over the two year period. Days at maximum growth occurred later for males than for females (P <0.05) and the maturing rate of males and females did not differ significantly. Individual average feed intakes were calculated from the group fed animals over the duration of the rearing period. The data revealed that feed intake for bulls can be predicted by the linear model, DMI= 0.16531 + 0.0235306 x live weight (P ≤0.001; R 2 = 78.25). The feed intake of heifers can be predicted by the linear model, DMI= -1.41991 + 0.0283891 x live weight (P ≤0.001; R 2= 76.25). Analysis of variance detected no difference between the percentage feed intake of heifers (2.46%) and bulls (2.40%), over the experimental period. Prices of different live weight groupings were analysed over seven years to establish whether cyclical price trends can be observed across years and seasonal price trends within years. Within years prices were found to differ between months. For all calf weight groups, the lowest prices occurred in the months of March, April, May, June and July which showed price indices significantly different (P <0.05) from indices of the months of October, November and December when highest prices occurred, confirming seasonality in weaner calf prices. Price indices were developed for use as an input in the economic viability assessment. A brief literature review on the production and quality of four common pastures in the Southern Cape was done to gather information for compiling pasture budgets for use in determining the economic viability of pasture backgrounding. The economic viability of backgrounding on pastures was evaluated on a gross margin level and illustrated for three pasture systems namely irrigated oats as a winter pasture, irrigated lucerne as a spring pasture and dryland P. clandestinum /E. plana /mixed grass also as a low-cost spring pasture. All three pasture systems showed a positive economic viability for the decision parameters used in the illustration. The gross margin of backgrounding on the oats pasture system was more sensitive to a small decrease in the predicted price or the predicted live weight and therefore a riskier option than backgrounding on the other two systems. Outputs from the gross margin analyses were used in partial budgeting to illustrate a robust decision support framework that beef farmers can use for making decisions whether to sell weaners straight after weaning as opposed to selling after a period of backgrounding on pastures. Overall results indicate that backgrounding of calves on pastures has the potential to be a viable beef enterprise on smaller farms in the region. Keywords: beef production; Gompertz growth curves, feed intake; pasture backgrounding; gross margin; partial budgets.
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  • Date Issued: 2020

Compounds isolation and biological activities of Piptadeniastrum africanum (hook. f.) Brennan (Fabaceae) roots:

  • Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
  • Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
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  • Date Issued: 2020

Cytotoxicity of triterpenoids from Clerodendrum glabrum against triple negative breast cancer cells in vitro:

  • Authors: Teclegeorgish, Zecarias W , Mokgalaka, Ntebogeng S , Vukea, Nyeleti , de la Mare, Jo-Anne , Tembu, Vuyelwa J
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/161511 , vital:40634 , https://doi.org/10.1016/j.sajb.2020.07.009
  • Description: Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β hydroxy 5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines.
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  • Date Issued: 2020

Resource recovery options in brewery effluent treatment using activated sludge and high rate algal ponds: assessing environmental impacts

  • Authors: Taylor, Richard Peter
  • Date: 2020
  • Subjects: Sewage -- Purification -- Activated sludge process , Sewage disposal plants , Sewage -- Purification -- Biological treatament , Sewage -- Purification -- Nitrogen removal , Brewery waste , Breweries -- Waste disposal , Microalgae -- Biotechnology , Algal biofuels
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/153746 , vital:39507
  • Description: Wastewater treatment plants (WWTPs) are designed to clean effluents, but they also consume resources and produce waste. Various treatment technologies allow for the recovery of energy, nutrients and water from effluents turning this waste into products, which increases their sustainability and decreases the impact of WWTPs on the environment. There is a lack of literature which comprehensively compares the treatment performances, environmental impacts and beneficial downstream uses of the biomass generated by high rate algal pond (HRAP) and activated sludge (AS) treatment systems. This thesis aimed to compare (1) effluent treatment performance, (2) emissions and (3) downstream use of algae cultured in HRAP to sludge produced in AS and to obtain data to conduct a life cycle analysis (LCA) to compare the systems. The focus was on adding value to the effluent treatment process, while identifying the associated environmental impacts and contributing to the first ever zero-waste brewery effluent treatment system. Furthermore, these data were used to provide a basis to critically review and contribute to improving the methods used in the LCA of effluent treatment systems; particularly since this was the first wastewater treatment LCA that compared AS and HRAP using data collected from the same temporal and geographic location and from a single effluent stream. The electrical consumption water emission and land application of waste biomass caused the major environmental impacts of both treatment systems. The HRAP had less than 50 % of the electrical energy consumption (0.11±0.01 kW/m3 of effluent treated) compared to the AS system (0.29±0.11 kW/m3) which resulted in the technology having a lower climate change, photochemical oxidant formation, freshwater and marine ecotoxicity and fossil fuel depletion impact. It is imperative to understand the method of electrical energy (fossil fuel vs renewable) generation when conducting a LCA and deciding which technologies to use, since they have a major influence on the aforementioned impacts. The biogas yield of algal and sludge substrates was similar with an average gas production of 241 ml/g volatile solids fed. Biogas from algae fed digesters had a significantly higher methane content (64.73±0.81 %) and lower carbon dioxide content (22.94±0.24 %) when compared to WAS fed digesters (60.08±0.18 % and 27.37±0.43 %) respectively due to it being a less oxidised substrate. Swiss chard plants (Beta vulgaris) fertilised with anaerobically digested (AD) algae or sludge had a significantly higher mean biweekly yield (5.08±0.73 kg/m2) when compared to the inorganic-fertiliser control (3.45±0.89 kg/m2; p<0.0001). No difference was observed in the soil’s physical fertility when algae or sludge were applied to the soil (p>0.05). The HRAP produced more biomass (317.18±27.76 g/m3) than the AS (83.12±64.91 g/m3), which resulted in a significantly greater downstream production of biogas and fertiliser per volume of effluent treated. According to the LCA, this also resulted in the HRAP system having a higher terrestrial ecotoxicity, due to the greater volume of solids and thus heavy metals applied to the soil. This interpretation can be misleading, because the mass of heavy metals released into the environment is the same for both systems, with a greater portion being applied to the land in the HRAP scenario and discharged into fresh water in the case of AS. Future LCA models should clarify if these biomasses are going to be applied to a single piece of land or multiple sites as this will influence the risk of contamination via pollutant build up in the soil. The application of sludge or algae on soil increased the soil’s sodium concentration and sodium absorption ratio from 774.80±13.66 mg/kg to 952.17±34.89 mg/kg and 2.91±0.04 to 3.53±0.13, respectively. Regulations on the application of algae or sludge on agricultural soils should be altered to consider the limit values for sodium and future LCA’s associated with effluent treatment facilities should incorporate the possibility of soil contamination through sodium build-up. This work also conceptualised the importance of reporting water emissions in wastewater treatment LCA in as much detail as possible, because this had a significant influence on the eutrophication impacts on water systems. Reporting water emissions as total nitrogen underestimated downstream eutrophication impacts compared with those using nitrogen-species concentration (ammonia, nitrite, nitrate etc). A marine eutrophication sensitivity co-efficient should be included in future LCA models which accounts for the probability of nitrogen and phosphorus emissions entering the coastal environment as well as the vulnerability of the marine environment to eutrophication. Activated sludge systems are favourable for situations where space is limited, were there are inadequate options for biomass disposal (biomass not be used in agriculture or AD) and were electricity is generated from a renewable source; whereas, HRAP are more suitable under circumstances where electricity production relies on fossil fuel that carries a high environmental impact and where options are available to use the biomass for economic gain such as biogas and fertiliser production. This thesis contributes towards a zero-waste brewery effluent treated process. The HRAP and AS treated effluent for reuse in the brewery or in agricultural irrigation. The solids were anaerobically digested, and the carbon was recovered as a biogas, while the digestate was applied as an agricultural fertiliser. This allowed for the recovery of water, nutrients and carbon.
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  • Date Issued: 2020

Biomes, geology and past climate drive speciation of laminate-toothed rats on South African mountains (Murinae: Otomys)

  • Authors: Taylor, Peter J , Kearney, Theresa , Dalton, Desire L , Chakona, Gamuchirai , Kelly, Christopher M , Barker, Nigel P
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/425481 , vital:72249 , xlink:href="https://doi.org/10.1093/zoolinnean/zlz134"
  • Description: Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).
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  • Date Issued: 2020

Habitat requirements affect genetic variation in three species of mayfly (Ephemeroptera, Baetidae) from South Africa:

  • Authors: Taylor, Chantal L , Barker, Nigel P , Barber-James, Helen M , Villet, Martin H , Pereira-da-Conceicoa, Lyndall L
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/149314 , vital:38824 , https://doi.org/10.3897/zookeys.936.38587
  • Description: This study investigates genetic diversity in three species of Ephemeroptera, one eurytopic and therefore widespread (Afroptilum sudafricanum) and two stenotopic and thus endemic (Demoreptus natalensis and Demoreptus capensis) species, all of which co-occur in the southern Great Escarpment, South Africa. Mitochondrial DNA was analysed to compare the genetic diversity between the habitat generalist and the two habitat specialists. Afroptilum sudafricanum showed no indication of population genetic structure due to geographic location, while both Demoreptus species revealed clear genetic differentiation between geographic localities and catchments, evident from phylogenetic analyses and high FST values from AMOVA.
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  • Date Issued: 2020

Gamma-Ray and X-Ray Observations of the Periodic-repeater FRB 180916 during Active Phases:

Non-standard employment in terms of the labour relations act

  • Authors: Tatchell, Veronique
  • Date: 2020
  • Subjects: Labor laws and legislation -- South Africa , South Africa -- Labour Relations Act, 1995 , Flexible work arrangements -- South Africa
  • Language: English
  • Type: Thesis , Masters , LLM
  • Identifier: http://hdl.handle.net/10948/49027 , vital:41594
  • Description: Historically, employers utilised non-standard or atypical forms of employment in order to avoid statutory obligations in respect of these employees, and in turn justify differential treatment of said employees.1 As a result, non-standard employees were not on the same footing as their permanent counterparts. They were not remunerated on the same level, were not privy to advancement and training opportunities, and did not enjoy a sense of job security due to the ease at which their employment could be terminated, rendering them a vulnerable class of workers.2 There was pandemonium in the employment sphere of society due to the abusive practices faced by employees employed in terms of Temporary Employment Services, this was accompanied by a call to ban labour broking. The legislature, while acknowledging the important role that this form of employment plays in the labour market and broader economy, opted for increased regulation of this and other types of non-standard employment; instead of an outright ban. As a result thereof, the Labour Relations Act3 was amended by the Labour Relations Amendment Act,4 with a view of improving the regulation and protection of employees engaged in these forms of non-standard or atypical employment. This study seeks to determine whether the amendments have achieved the purpose of enhancing the job security of these employees.
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  • Date Issued: 2020

High genetic diversity and limited spatial structure in an endangered, endemic South African sparid, the red steenbras Petrus rupestris:

  • Authors: Tang, Wei , Qiu, Yuanyuan , Li, Xiaonan , Soy, Rodah C , Mack, John , Nyokong, Tebello
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/160390 , vital:40441 , DOI: 10.6060/mhc200183l
  • Description: Earth-abundant first row transition metal corrole complexes have played an important role in fundamental research due to their unique molecular structures and attractive properties. In comparison to porphyrins, corroles have three inner N-H protons and are ring-contracted with a smaller macrocyclic cavity. First row transition metal corroles have been widely used as effective electrochemical catalysts for small molecule activations, such as hydrogen evolution, oxygen reduction/evolution and CO2 reduction reactions (HERs, ORRs/OERs and CO2 RRs) through homogenous and/or heterogenous prodecures. Several strategies have been used to modulate the catalytic efficiency of synthetic metallocorroles.
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  • Date Issued: 2020

The Influence of Clientelism on the Informal Sector in Zimbabwe : a Case Study of Glen View 8 Complex, Harare

  • Authors: Tandire, Justin
  • Date: 2021-04
  • Subjects: Patron and client -- Zimbabwe -- Harare , Informal sector (Economics) -- Zimbabwe -- Harare , Informal sector (Economics) -- Political aspects -- Zimbabwe -- Harare , Patronage, Political -- Zimbabwe -- Harare , ZANU-PF (Organization : Zimbabwe) , Zimbabwe -- Social conditions , Glen View Complex 8 (Zimbabwe)
  • Language: English
  • Type: thesis , text , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/177986 , vital:42896 , 10.21504/10962/177986
  • Description: This study focuses on the influence of clientelism in the informal sector of Zimbabwe in Glen View 8 (Complex). The study used the case of Glen view 8 (complex) in Harare Province. The study focused on political dynamics in the informal sector; livelihood strategies employed by informal sector operators; manifestation of “Big Men”, social networks in the informal sector; and different strategies employed by operators to overcome the problems of political manipulation, clientelism and patronage. It employs a qualitative research methodology to enable a nuanced comprehension of the clientelistic relationships that take place in the informal sector of Zimbabwe. Through in-depth interviews, focus group discussions, narratives and in-depth interviews with key informants, the study explored the clientelistic nature of the informal sector. The major findings of the study are that the informal sector in Zimbabwe is influenced by political patronage. It was established that patronage influences the informal sector in Zimbabwe in general and at Glen View Complex 8 in particular. Some of the operators revealed that patronage negatively affects their business as they are sometimes forced to attend political party meetings either at the complex or at ZANU-PF star rallies in town. The operators experience a plethora of problems such as lack of security, poor sanitation, stiff competition, poor infrastructure, lack of insurance and fire outbreaks. It has been revealed that most of the problems experienced at the complex are a result of the politicisation of the informal sector particularly by the ZANU-PF party. Operators at the complex have described the politicisation of the informal sector as a major drawback to their efforts of realising maximum benefits from their work. Therefore, the thrust of this thesis is premised on the de-politicisation of the informal sector as the starting point in the transformation of the activities of the operators. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
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  • Date Issued: 2021-04

Dataset and ANN model prediction of performance of graphene nanolubricant with R600a in domestic refrigerator system

  • Authors: Taiwo, Babarinde , Stephen, Akinlabi , Daniel Makundwaneyi, Madyira , Ekundayo, Funmilayo M , Paul Adeola, Adedeji
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/3139 , vital:43150 , (https://www.sciencedirect.com/science/article/pii/S2352340920309926)
  • Description: This work evaluated the steady state performance of R600a in the base lubricant and graphene nanolubricant. The measuring instruments required and their uncertainties were provided, step by step method and procedures for preparation of graphene nanolubricant concentration and substituting it with the base lubricant in domestic refrigerator system are described. The system temperatures data was captured at the inlet and outlet of the system components. Also, the pressures data was recorded at the compressor inlet and outlet. The data was recorded for 3 h at 30 min interval at an ambient temperature of 27 °C. The experimental dataset, Artificial Neural Network (ANN) training and testing dataset are provided. The artificial intelligence approach of ANN model to predict the performance of graphene nanolubricant in domestic refrigerator is explained. Also, the ANN model prediction statistical performance metrics such as Root Mean Square Error (RMSE) and Mean Absolute Deviation (MAD), Mean Absolute Percentage Error (MAPE) and coefficient of determination (R2) are also provided. The data is useful to researchers in the field of refrigeration and energy efficiency materials, for replacing nanolubricant with the base lubricant in refrigerator systems. The data can be reuse for simulation and modelling vapour compression energy system.
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  • Date Issued: 2020

Ethics and education as practices of freedom

  • Authors: Tabensky, Pedro
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/305672 , vital:58602 , xlink:href="https://doi.org/10.1080/00131857.2020.1791822"
  • Description: On the one hand, according to Richard Rorty, Paulo Freire and others, education is the practice of freedom. On the other hand, according to Michael Foucault, Mary Midgley and others, ethics is the practice of freedom. How, then, are education and ethics related to one another and what do these authors mean by ‘the practice of freedom’? In this piece, I argue that education and ethics are two mutually constitutive aspects of the practice of freedom. Individuals who are able to engage in this practice can most properly be said to be the authors of their lives, that is, individuals who, to borrow from Neil MacGregor, are able to find their ‘place in things’. To find our ‘place in things’ is to do the necessary educative work required for becoming the authors of our lives, that is, for self-actualization (as Rorty and John Dewey have argued). To take on the authorial role is, moreover, to be able effectively to take control of our lives, to organize them into unities for which we are individually responsible. This, according to Midgley, is precisely what it is to be ethical. This work, moreover, requires ongoing development, that is, education, in Dewey’s sense. I further argue that professional education and skills training cannot be understood properly in isolation from these broader educational aims and I criticize mainstream educational practices for not paying sufficient attention to the intimate relationship between the vocational and non-vocational aspects of education.
  • Full Text:
  • Date Issued: 2020

Detection of the in vitro modulation of Plasmodium falciparum Arf1 by Sec7 and ArfGAP domains using a colorimetric plate-based assay:

  • Authors: Swart, Tarryn , Khan, Farrah D , Ntlantsana, Apelele , Laming, Dustin , Veale, Clinton G L , Przyborski, Jude M , Edkins, Adrienne L , Hoppe, Heinrich C
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/165418 , vital:41242 , https://0-doi.org.wam.seals.ac.za/10.1038/s41598-020-61101-3
  • Description: The regulation of human Arf1 GTPase activity by ArfGEFs that stimulate GDP/GTP exchange and ArfGAPs that mediate GTP hydrolysis has attracted attention for the discovery of Arf1 inhibitors as potential anti-cancer agents. The malaria parasite Plasmodium falciparum encodes a Sec7 domain-containing protein - presumably an ArfGEF - and two putative ArfGAPs, as well as an Arf1 homologue (PfArf1) that is essential for blood-stage parasite viability. However, ArfGEF and ArfGAP-mediated activation/deactivation of PfArf1 has not been demonstrated.
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  • Date Issued: 2020

Development of Tio 2 nanostructure arrays for photonic extraction of hydrogen gas

  • Authors: Suliali, Nyasha Joseph
  • Date: 2020
  • Subjects: Nanostructures , Nanostructured materials Hydrogen
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/49314 , vital:41620
  • Description: Amid the energy crisis of the 21st century, renewable energy is a thriving field of study, light harvesting materials being a central theme due to the abundance of solar energy. Nanostructured TiO2 is the most studied photocatalysis material, since the discovery of its energy harvesting properties by Fujishima and Honda in 1972. Environmentally friendly products such as hydrogen fuel, can be produced using TiO2 due to its non-toxicity, chemical stability and photocatalytic activity. The surprising aspect of this important material is that it can be prepared using cost-effective methods such as hydrothermal synthesis, solution gelation and anodic oxidation. This research focused on the three key elements required to develop TiO2 photoelectrodes i.e. the deposition of Ti films on transparent substrates, a thorough analysis of the chemistry of the anodic oxidation process and the development of the TiO2 thin films. Glass substrates that have Ti films are the base component for TiO2 photoelectrode production. Ti films with thicknesses up to 4 μm, were developed on commercial F-doped SnO2 (FTO) glass substrates using high-power impulse magnetron sputtering (HiPIMS). The sputter deposition experiments were performed in the 1 to 8 kW range at a substrate temperature of 500 °C and Ar pressure of 400 mPa. At higher powers, thicker films were deposited, resulting in increased intensity of Xray-diffraction peaks. However, on comparing the XRD patterns, the (001) peak outgrew the rest regardless of thickness of the film. The deposition process therefore favoured orientation of most of the α-Ti phase crystallites with the [001] axis perpendicular to the substrate surface. Surface roughness results were interesting, showing a non-linear dependence of the surface roughness on HiPIMS pulse energy in the 1 to 8 kW range. The surface roughness is highest at the starting deposition power of 1450 W and reduces to a minimum at 4500 W. From this minimum, it increases to its second highest value at 7900 W. From this data, the parameters required to produce Ti films of lowest surface roughness, for deposition on commercial Technistro® FTO glass, were deduced at the inflection point, where the deposition power was 4500 W. The surface roughness obtained is a critical result for the anodic production of quality TiO2 photoelectrodes, which if high, leads to uneven etching, thus irregular and inefficient photoelectrodes. Direct current magnetron sputtering was also carried out in the 1 to 5 kW range to obtain ratios of power-normalised growth rates of the Ti films. This investigation provided the Ti films on FTO glass, the transparent, conductive substrates which were used to develop TiO2 photoelectrodes. To elucidate the chemistry of anodic oxidation of Ti, a mathematical model of the anodic current density, which had not been reported at the time of its publication, was developed. The technique, a highlight of this research, is a predictive numerical computation of the instantaneous quantities of species that participate in the anodization process. From eleven chemical reactions, 14 first order ordinary differential equations were compiled using the principles of chemical reaction kinetics. The pattern, transient behaviour and response to anodization parameters of the current density signal, were successfully predicted. Strong agreement between the model and measurements was demonstrated in seven experiments. The results confirm that the current density signal is a numerical integral of the kinetics of redox reactions of water. The bulk of this research was on the development of TiO2 nanotubular arrays on Ti foil substrates and Ti films on FTO glass. TiO2 films with well-defined tubular structures were synthesised. The films were developed in anhydrous, polar organic hosts with water and etching agents in the range of 10 V to 70 V. The control of geometrical properties of the tubes such as the length, pore diameter, wall thickness, tube separation and number of nanotubes per unit area was demonstrated. Anatase only and mixed anatase-rutile phase compositions were obtained at different annealing temperatures. Nanotubes with diameters as small as 20 nm and thickness as high as 29 μm were produced. Apart from an increase in nanotube thickness, a decrease in distance between nanotubes grown in diethylene glycol was observed at longer anodization times. Studies of the effects of anodization parameters on the current density measured, morphological and crystallographic properties of the nanotube films were conducted in three main investigations. The first was the study of the effect of anodization parameters on current density. Besides the obvious increase of current density with anodic voltage, the first steady state of the growth process was found to depend on the NH4F concentration. The second investigation focused on the effect of accelerated growth of TiO2 nanotubular films. In the study, 9 μm-thick nanotube films were synthesised at twice the growth rate of a 9 μm-thick control sample. The array obtained by accelerated growth had distinguishable nanotubes, however, the morphological quality was reduced. The third investigation demonstrates the control of the number of nanotubes per unit area. By varying the etchant content, the anodic voltage and the viscosity of the electrolyte host, various distributions were obtained. The research ends with a photoelectrochemical application: measurement on photocurrents generated in a two-electrode setup. The photocurrent densities measured in the off and on conditions were 30 nA/cm2 and 2.57 μA/cm2, respectively, demonstrating photoactivity of the developed films.
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  • Date Issued: 2020

Oral Phytothymol ameliorates the stress induced IBS symptoms

  • Authors: Subramaniyam, Selvaraj , Yang, Shuyou , Diallo, Bakary N , Fanshu, Xu , Lei, Luo , Li, Chong , Tastan-Bishop, Özlem , Bhattacharyya, Sanjib
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426034 , vital:72308 , xlink:href="https://doi.org/10.1038/s41598-020-70420-4"
  • Description: Physical stressors play a crucial role in the progression of irritable bowel syndrome (IBS). Here we report a heterogeneous physical stress induced IBS rat model which shows depression and subsequent modulation of IBS by oral treatment of thymol. Oral administration of Thymol reduces the stress induced IBS significantly altering the stress induced gastrointestinal hypermotility, prolonged the whole gut transit time, and increased abdominal withdrawal reflex suggesting gastrointestinal hypermotility and visceral discomfort caused the onset of depression. Immunohistochemical analysis in small intestine and colon of rats shows the decreased 5-HT3AR expression level while thymol treatment normalized the 5-HT3AR expression in the stressed rats. Molecular docking studies showed that thymol competes with endogenous serotonin and an antagonist, Tropisetron and all have similar binding energies to 5-HT3AR. Molecular dynamics simulations revealed that thymol and tropisetron might have similar effects on 5-HT3AR. Our study suggest that thymol improves IBS symptoms through 5-HT3AR, could be useful for the treatment of IBS.
  • Full Text:
  • Date Issued: 2020

Shrub and bird community response to fire in dune thicket of the southeastern Cape, South Africa

  • Authors: Strydom, Tiaan
  • Date: 2020
  • Subjects: Fire prevention -- Research -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10948/47635 , vital:40260
  • Description: Fire studies within the Cape Floristic Region (CFR) are restricted to the impacts of fire on plants and birds in fire-prone fynbos while little is known about post-fire responses of shrubs and birds in fire-avoiding subtropical dune thicket, which coexists with fynbos but burns on much longer cycles. Fire is deemed important for maintaining the boundaries between fynbos and thicket. It has been hypothesised that high-intensity fires prevent fire-dependent fynbos from being replaced by fireavoiding subtropical thicket (hereafter thicket) on dune landscapes of the CFR. I posit that (1) fire-related thicket shrub mortality would be size dependent, with smaller individuals suffering higher mortality than larger ones; and (2) that survival and resprouting vigour of thicket shrubs would be negatively correlated with fire intensity. In relation to the response of birds to fire I posit that (1) fire reduces bird species richness and bird abundance in thicket during the first two years post-fire; and (2) fire changes feeding guild composition and results in the loss of frugivorous birds. Extensive fires in dune thicket along the southeastern Cape coast presented the opportunity to assess the responses of thicket shrubs and birds to fire. For the thicket shrubs I assessed survival and resprouting vigour of thicket shrubs post-fire in relation to fire intensity and pre-fire shrub size at two dune landscapes (Cape St Francis and Knysna) in the CFR. I furthermore compared bird species richness, bird abundance and feeding guild composition between burnt and unburnt thicket (only at Knysna). A total of 29 species and 1112 individuals of thicket shrub were surveyed, with post-fire survival being high (83-85%). Smaller shrubs had a lower probability of post-fire survival than larger individuals but there was no consistent relationship between shrub mortality and fire intensity. Fire intensity had a positive effect on resprouting shoot count but a variable effect on resprouting volume. In the bird study a total of 66 bird species and 2404 individuals were recorded of which 52 species and 1176 individuals were in burnt thicket and 60 species and 1228 individuals were in unburnt thicket. Ten species occurred only in burnt thicket and 13 species only in unburnt thicket. Insectivores and generalists were the most common feeding guilds in terms of richness and abundance in both burnt and unburnt thicket. Frugivores were more abundant in unburnt thicket than burnt thicket, whereas granivores were more abundant in burnt thicket than unburnt thicket. I conclude that thicket shrubs and bird communities are resilient to fire. Prescribed high-intensity fires in dune landscapes are unlikely to reduce the extent of thicket in fynbos or radically change the bird communities. The effects of fire on thicket shrubs and birds are likely to be short-lived as thicket shrubs resprout vigorously after fire resulting in rapid recovery of vegetation and thus bird habitat structure. However, frequent fires may prevent the encroachment of thicket shrub juveniles into fynbos, owing to the greater vulnerability of small shrubs to fire. Most recruitment of thicket shrub individuals into fynbos is via ramets that likely originate from well-established plants in mature thicket stands. These mature unburnt thicket stands provide habitat for various forest bird species and can function as refuge areas for birds and other wildlife in fire-prone landscapes. However, there is no need for managers to take any precautions when implementing controlled burns or controlling wildfires because not all thicket patches in the landscape are likely to burn.
  • Full Text:
  • Date Issued: 2020
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