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A reappraisal of the origin of the Hotazel Fe-Mn Formation in an evolving early Earth system through the application of mineral-specific geochemistry, speciation techniques and stable isotope systematics

  • Authors: Mhlanga, Xolane Reginald
  • Date: 2020
  • Subjects: Manganese ores -- South Africa -- Hotazel , Manganese ores -- Geology , Iron ores -- South Africa -- Hotazel , Iron ores -- Geology , Geochemistry -- South Africa -- Hotazel , Isotope geology -- South Africa -- Hotazel , Geology, Stratigraphic -- Archaean , Geology, Stratigraphic -- Proterozoic , Transvaal Supergroup (South Africa) , Great Oxidation Event
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/146123 , vital:38497
  • Description: Marine chemical sediments such as Banded Iron Formations deposited during the Archean-Palaeoproterozoic are studied extensively because they represent a period in the development of the Earth’s early history where the atmospheric O₂ content was below the present levels (PAL) of 21%. Prior to the Great Oxidation Event (GOE) at ca. 2.4 Ga, highly ferruginous and anoxic marine environments were dominated by extensive BIF deposition such as that of the Griqualand West Basin of the Transvaal Supergroup in South Africa. This basin is also thought to record the transition into the first rise of atmospheric O₂ in our planet, from the Koegas Subgroup to the Hotazel Formation dated at ca. 2.43 Ga (Gumsley et al., 2017). Two drill cores from the north eastern part of the Kalahari Manganese Field characterized by a well-preserved and complete intersection of the cyclic Mn-Fe Hotazel Formation were studied at a high resolution (sampled at approximately one-meter interval). Such high-resolution approach is being employed for the first time in this project, capturing in detail the three manganese rich layers intercalated with BIF and the transitions between these lithofacies. The micro-banded BIF is made up of three major phases, namely Fe-Ca-Mg carbonates (ankerite, siderite and calcite), magnetite, and silicates (chert and minor Fe-silicates); laminated transitional lutite consist of mainly hematite, chert and Mn-carbonates, whereas the manganese ore layers are made up of mostly calcic carbonates (Mn-calcite and Ca-kutnahorite) in the form of laminations and ovoids, while Mn-silicates include dominant braunite and lesser friedelite. All three lithofacies are very fine grained (sub-mm scale) and so petrographic and mineralogical observations were obtained mostly through scanning electron microscope analysis for detailed textural relationships with focus on the carbonate fraction. Bulk geochemical studies of the entire stratigraphy of the Hotazel Formation have previously provided great insights into the cyclic nature of the deposit but have not adequately considered the potential of the carbonate fraction of the rocks as a valuable proxy for understanding the chemistry of the primary depositional environment and insights into the redox processes that were at play. This is because these carbonates have always been attributed to diagenetic processes below the sediment-water interface such as microbially-mediated dissimilatory iron/manganese reduction (DIR/DMR) where the precursor/primary Fe-Mn oxyhydroxides have been reduced to result in the minerals observed today. The carbonate fraction of the BIF is made up of ankerite and siderite which co-exist in a chert matrix as anhedral to subhedral grains with no apparent replacement textures. This suggests co-precipitation of the two species which is at apparent odds with classic diagenetic models. Similarly, Mn-carbonates in the hematite lutite and manganese ore (Mn-calcite, kutnahorite, and minor rhodocrosite) co-exist in laminae and ovoids with no textures observed that would suggest an obvious sequential mode of formation during diagenesis. In this light, a carbonate-specific geochemical analysis based on the sequential Fe extraction technique of Poulton and Canfield (2005) was employed to decipher further the cyclic nature of the Hotazel Formation and its primary versus diagenetic controls. Results from the carbonate fraction analysis of the three lithofacies show a clear fractionation of iron and manganese during primary – rather than diagenetic - carbonate precipitation, suggesting a decoupling between DIR and DMR which is ultimately interpreted to have taken place in the water column. Bulk-rock concentration results for minor and trace elements such as Zr, Ti, Sc and Al have been used for the determination of either siliciclastic or volcanic detrital inputs as they are generally immobile in most natural aqueous solutions. These elements are in very low concentrations in all three lithofacies suggesting that the depositional environment had vanishingly small contributions from terrigenous or volcanic detritus. In terms of redox-sensitive transition metals, only Mo and Co appear to show an affinity for high Mn facies in the Hotazel sequence. Cobalt in particular attains a very low abundance in the Hotazel BIF layers at an average of ~ 4 ppm. This is similar to average pre-GOE BIF in South Africa and worldwide. Maxima in Co abundance are associated with transitional hematite lutite and Mn ore layers, but maxima over 100ppm are seen in within the hematite lutite and not within the Mn ore proper where maxima in Mn are recorded. This suggests a clear and direct association with the hematite fraction in the rocks, which is modally much higher in the lutites but drops substantially in the Mn layers themselves. The similarities of bulk-rock BIF and modern-day seawater REE patterns has been used as a key argument for primary controls in REE behaviour and minimal diagenetic modification. Likewise, the three lithofacies of the Hotazel Formation analysed in this study all share similar characteristics with a clear seawater signal through gentle positive slopes in the normalised abundance of LREE versus HREE. Negative Ce anomalies prevail in the entire sample set analysed, which has been interpreted before as a proxy for oxic seawater conditions. However, positive Ce anomalies that are traditionally linked to scavenging and deposition of primary tetravalent Mn oxyhydroxides (e.g., as observed in modern day ferromanganese nodules) are completely absent from the current dataset. The lack of a positive Ce anomaly in the manganese ore and peak Co association with ferric oxides and not with peak Mn, suggests that primary deposition must have occurred within an environment that was not fully oxidizing with respect to manganese. The use of stable isotopes (i.e., C and Fe) was employed to gain insights into redox processes, whether these are thought to have happened below the sediment-water interface or in contemporaneous seawater. At a small scale, all lithofacies of the Hotazel Formation record bulk-rock δ¹³C values that are low and essentially invariant about the average value of -9.5 per mil. This is independent of sharp variations in overall modal mineralogy, relative carbonate abundance and carbonate chemistry, which is clearly difficult to reconcile with in-situ diagenetic processes that predict highly variable δ¹³C signals in response to complex combinations of precursor sediment mineralogy, pore-fluid chemistry, organic carbon supply and open vs closed system diagenesis. At a stratigraphic scale, the carbonate δ¹³C (-5 to -13‰) variations between the different lithologies could instead represent temporal changes in water-column chemistry against well-developed physico-chemical gradients, depth of deposition and biological processes. The low iron isotope values recorded in the hematite lutite and manganese ore samples can be attributed to fractionation effects of initial oxidation of ferrous iron to form Fe-oxyhydroxides in the shallow parts of the basin, from an already isotopically highly depleted aqueous Fe-pool as proposed previously. The slightly higher but still negative bulk-rock δ⁵⁶Fe values of the host BIF can be attributed to water-column Fe isotopic effects at deeper levels between primary Fe oxyhydroxides and an isotopically heavier Fe(II) pool, which was subsequently preserved during diagenetic recrystallization. All above findings were combined into a conceptual model of deposition for the three different lithologies of the Hotazel Formation. The model predicts that free molecular oxygen must have been present within the shallow oceanic environment and implicates both Mn and Fe as active redox “players” compared to classic models that apply to the origin of worldwide BIF prior to the GOE. The deposition of the Hotazel strata is interpreted to have occurred through the following three stages: (1) BIF deposition occurred in a relatively deep oceanic environment above the Ongeluk lavas during marine transgression, where a redoxcline and seawater stratification separated hydrothermally sourced iron and manganese, in response to an active Mn-shuttle mechanism linked to Mn redox cycling. Abundant ferrous iron must have been oxidized by available oxygen but also by oxidised Mn species (MnOOH) and possibly even some soluble Mn(III) complexes. Through this process, Mn(III) was being effectively reduced back into solution along with cobalt(III), as Mn(II) and Co(II) respectively, thus creating maxima in their concentrations. A drawdown of Fe(OH)₃ particles was therefore the only net precipitation mechanism at this stage. Carbonate species of Fe and the abundant magnetite would possibly have formed by reaction between the ferric hydroxides and the deeper Fe(II) pool, while organic matter would also have reacted in the water-column via DIR, accounting for the low δ¹³C signature of Fe carbonate minerals. (2) Hematite lutite formation would have occurred at a relatively shallower environment during marine regression. At this stage, reductive cycling of Fe was minimal in the absence of a deeper Fe(II) reservoir reacting with the ferric primary precipitates. Therefore, DIR progressively gave way to manganese reduction and organic carbon oxidation (DMR), which reduced MnOOH to form Mn(II)-rich carbonates in the form of kutnahorite and Mn-calcite. Co-bearing Fe(OH)₃ would have precipitated and was ultimately preserved as Co-bearing hematite during diagenesis. (3) Deposition of manganese-rich sediment occurred at even shallower oceanic depths (maximum regression) where aerobic organic carbon oxidation replaced DMR, resulting in Ca-rich carbonates such as Mn-bearing calcite and Ca-kutnahorite, yet with a low carbon isotope signature recording aerobic conditions of organic carbon cycling. Mn(III) reduction at this stage was curtailed, leading to massive precipitation of MnOOH which was diagenetically transformed into braunite and friedelite. Simultaneous precipitation of Co-bearing Fe(OH)₃ would have continued but at much more subdued rates. Repeated transgressive-regressive cycles resulted in the cyclic BIF-hematite lutite- manganese ore nature of the Hotazel Formation in an oxidized oceanic environment at the onset of the Great Oxidation Event, which was nonetheless never oxic enough to drive Mn(II) oxidation fully to its tetravalent state. The mineralogy and species-specific geochemistry of the Hotazel strata, and more specifically the carbonate fraction thereof, appear to faithfully capture the chemistry of the primary depositional environment in a progressively evolving Earth System. This project opens the door for more studies focusing on better constraining primary versus diagenetic depositional 2020 Hotazel Fe and Mn deposition mechanisms of iron and manganese during the period leading up to the GOE, and possibly re-defining the significance of Fe and Mn as invaluable redox proxies in a rapidly changing planet.
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  • Date Issued: 2020

A scheduling model for the charging of electric vehicles in photovoltaic powered smart microgrids

  • Authors: Nyumbeka, Dumisani Joshua
  • Date: 2020
  • Subjects: Electric vehicles , Photovoltaic power generation Photovoltaic power generation -- Developing countries
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/49259 , vital:41615
  • Description: Electric vehicles (EVs) have emerged as a viable option to advance sustainable mobility, but adoption is still relatively low. This has been largely due to the limited range one can travel on a single charge, leading to range anxiety, longer charge cycles and long wait times at charging stations. One solution to range anxiety is to erect charging stations on major roads and urban centres. There is also a lack of real-time information regarding the state of charging stations and charging ports in existing charging infrastructure. To increase the benefit of using EVs, using renewable energy sources, such as photovoltaics (PV) to power EVs, can further increase the benefit of reduced carbon footprint. The main research objective was to design a Charge Scheduling Model for charging EVs using a PV-powered smart microgrid (SMG). The model addresses the lack of an integrated platform where EV drivers can schedule when and where to charge their EVs. The model also reduces the negative effects of the adoption of EVs, including range anxiety. The Charge Scheduling Model was developed using the Design Science Research (DSR) methodology and was the main artefact of the study. A literature study was conducted of research related to SMGs, renewable energy, EVs and scheduling, to identify shortcomings that currently exist in EV charge scheduling (EVCS), and to identify the requirements of a potential solution. The literature study also identified the hard and soft constraints that are unique to EVCS, and the available energy in the SMG was identified as one of the hard constraints. Therefore, an Energy Forecasting Model for forecasting energy generated in PV-powered SMGs was required before the Charge Scheduling Model could be designed. During the first iteration of the design and development activities of DSR, four models were designed and implemented to evaluate their effectiveness in forecasting the energy generated in PV-powered SMGs. The models were Support Vector Regression (SVR), K-Nearest Neighbour (KNN), Decision Trees, and Multilayer Perceptron. In the second iteration, the Charge Scheduling Model was designed, consisting of a Four Layered Architecture and the Three-Phase Data Flow Process. The Charge Scheduling Model was then used to design the EVCS prototype. The implementation of the EVCS prototype followed the incremental prototyping approach, which was used to verify the effectiveness of the model. An artificial-summative evaluation was used to evaluate the design of the Charge Scheduling Model, whereas iterative formative evaluations were conducted during the development of the EVCS prototype. The theoretical contribution of this study is the Charge Scheduling Model, and the EVCS prototype is the practical contribution. The results from both evaluations, i.e. the Energy Forecasting Model and the Charge Scheduling Model, also make a contribution to the body of knowledge of EVs.
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  • Date Issued: 2020

A sociological understanding of contemporary child marriage in Mabvuku, Harare, Zimbabwe

  • Authors: Madzivire, Shamso Christine
  • Date: 2020
  • Subjects: Child marriage -- Zimbabwe -- Mabvuku , Child marriage -- Zimbabwe -- Case studies , Shona (African people) -- Social life and customs , Marriage customs and rites -- Zimbabwe , Shona (African people) -- Marriage customs and rites , Marriage -- Zimbabwe
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/142566 , vital:38091
  • Description: Child marriage is a phenomenon that has been increasingly recognised as a global problem since the late nineteenth century. Since then, scholars across many disciplines along with various agencies such as government bodies and non-governmental organisations have tirelessly engaged in research exploring the causes and consequences of this practice and in developing prevention and mitigation strategies. These research efforts have been concentrated in some parts of the world and not others, with the findings in many cases being generalised problematically across different geographical areas. This thesis stands as a response to the dearth of academic research on child marriage in present-day Zimbabwe and simultaneously highlights the significance of studying the specificities of child marriage under particular historical and spatial conditions. The main objective of this thesis is to explore and understand child marriage as a part of modernday marriage practices in Zimbabwe, through a case study of child marriage in Mabvuku in Harare. In addressing this objective, it is hoped that new ways of thinking around this phenomenon will become evident. In addressing this main objective, the thesis considers the experiences of child brides, the drivers and consequences of child and post-child marriage experiences. It does this seeking to understand child marriage with reference to the types of marital unions which exist amongst Shona people in pre-colonial times and in post-colonial Zimbabwe. The thesis adopts a qualitative research methodology which involved in-depth semistructured interviews with 25 women in Mabvuku who were married before the age of 18, along with focus group discussions with community workers and interviews with pertinent government and non-government representatives. Due to certain challenges with current theorising about child marriage, there is an attempt to build theory by drawing upon in particular the Zimbabwean notion and practice of hunhu. A key conclusion is that child marriage in present-day Zimbabwe is in part a result of family transitions which arose during the time of colonialism and continue to this day.
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  • Date Issued: 2020

A Strategic Model to Promote University of Choice Decisions among International Students Studying in South Africa

  • Authors: Jooste, Carlien
  • Date: 2020
  • Subjects: Internationalism -- Education (Higher) -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , DBA
  • Identifier: http://hdl.handle.net/10948/48191 , vital:40519
  • Description: The internationalisation of higher education has become an inevitable focus in the modern day higher education sector. This focus is due to the interconnectedness of society, which is driven by globalisation. The ever-changing landscape of the current global higher education sector has further placed emphasis on self-funding and the corporatisation of higher education institutions (HEIs). This has created competitiveness in the sector for local and international students, which has led to institutions globally and in South Africa, being tasked with the responsibility of being agents of internationalisation. The concept of higher education internationalisation involves internationalisation of the curriculum, cross-continental partnerships, the increase in mobility of staff and students, educational programmes, innovative ways of delivery as well as the need to be globally competitive. Students themselves view international study important as it provides them with a global outlook and international experience. The increased competitiveness in the higher education sector and the need for HEIs to become more autonomous and self-funded, has amplified the need to recruit international students who generate additional income. Furthermore, the strategy to recruit international students has evolved and transformed into a customer-driven strategy to meet the needs of the knowledge economy. To recruit international students, HEIs must invest in marketing and recruitment strategies, which build brand awareness and attract a diverse student body. This study investigates the development of a strategic university of choice model that can assist South African universities in the recruitment of international students by focusing on the factors, which influence a student’s university of choice. This was realised firstly by conducting a pilot study investigating the factors which influence the university of choice of students studying in South Africa. Secondly, the findings of the pilot study, combined with appropriate literature studies were used to develop a questionnaire to aid in determining the factors which influence the university of choice of international students studying in South Africa. Lastly, the findings of the questionnaire were used to draw conclusions and develop a proposed strategic model to promote the university of choice decisions among international students studying in South Africa. This thesis is an exploratory, mono-method quantitative study, which consists of literature reviews and surveys in a cross-sectional timeframe. The literature reviews were conducted on secondary sources to identify the factors that influence university of choice, as well as the marketing and recruitment trends within higher education. The empirical study consisted of a Pilot Study Survey and a Main Study Survey. The measuring instrument was compiled from existing surveys and literature studies. The findings of the Main Study Survey identified the following main factors of influence on university of choice: academic programme, academic quality, visa requirements, country/city attractiveness, English language, financial, International Office, student life, safety and security, university location and university reputation as main factors of influence. Within these main factors, various sub-factors were identified. The findings further illustrated that certain factors were more consultative in nature and provided information, which aided in the decision-making process. These factors are: motives to study/choose a programme, country attributes and influences/recruitment methods. Additionally, a third set of factors deemed to subconsciously influence the student’s decision-making process were identified as background of the student, study level and student type. The study contributes theoretically to Stakeholder Theory and Means-End Theory. Prospective students, who are higher education stakeholders, have diverse information needs and expectations, which will be met through the use of the proposed strategic model. Furthermore, the prospective students’ input will aid in the development of focused, targeted and cost-effective marketing and recruitment strategies, which will in turn meet the needs of universities to recruit a diverse student body.
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  • Date Issued: 2020

A Strategy for good IT Governance in South African Municipalities

  • Authors: Sibanda, Mbusi
  • Date: 2020
  • Subjects: Information technology -- Management -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , DIT
  • Identifier: http://hdl.handle.net/10948/49573 , vital:41737
  • Description: Information technology (IT) is widely used in South African municipalities as a tool for enabling business processes and therefore its design and implementation are critical to municipalities delivering on their core mandate of delivering services to their communities. The implementation of IT relies on the adoption of sound IT governance practices, whose outcome is to ensure that municipalities derive value from the use of IT and minimise the risk associated with it. However, the implementation of IT governance has proved to be challenging in most municipalities. This research sought to devise a strategic approach to the effective and viable implementation of IT governance in municipalities in South Africa. The research was carried out by adopting a design science research approach, which is increasingly being used for studies in the IT discipline as it assists in solving problems through the design of innovative artefacts, in this case a strategy for the implementation of IT governance. To address the objectives, the research was carried out through case studies of South African municipalities which enabled a detailed investigation of phenomena in its natural context. The data was collected by means of mixed methods consisting of a literature review, a survey and semi-structured interviews. A literature review connected to the research problem was done in order to identify the present state of the issues and how they have been confronted. A survey was sent out to municipalities, institutions and individuals with a mandate to support municipalities, while semi-structured interviews were conducted in five municipalities, government departments and regulatory bodies. A thematic analysis of the data collected was performed which led to a diagnosis of the issues. These include inadequate IT infrastructure; lack of coordinated external support; inadequate IT skills; lack of strong and committed IT leadership; poor IT controls; and fragmented planning. Guiding policies and a set of coherent actions for solving the issues were developed. This culminated in the devising of a strategy for the coordinated implementation of IT governance in municipalities. The primary contribution of this study is the formulation of a strategy for the sound implementation of IT governance in South African municipalities. The research contends that by identifying the strategic issues facing municipalities and implementing the proposed actions, most of which fall outside the municipalities, a new contribution to knowledge has been made. Accordingly, the strategy facilitates the development of plans that address the root causes of the poor implementation of IT in municipalities.
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  • Date Issued: 2020

A strategy towards implementing standardised data structures in municipal information systems

  • Authors: Koekemoer, Silma Marguerite
  • Date: 2020
  • Subjects: Data structures (Computer science) , Municipal government -- Data processing Public administration -- Data processing Management information systems
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/46064 , vital:39482
  • Description: The regulation pertaining to a Standard Chart of Accounts (SCOA) for Municipalities was published in 2014 and is applicable to all 257 municipalities and municipal entities in South Africa. The regulation represents a data classification framework or structure and affects all financial management and internal control systems (FMICS) used by municipalities and municipal entities, and affects key business processes within these organisations. Compliance with the SCOA regulation means that the full municipal accountability cycle should accommodate all seven of the SCOA segments, from the budget through transacting and reporting at the transaction level, with all seven of the segments being embedded in the master data table of the municipal FMICS. While the change to technology and systems may be self-evident, the related business change should not be underestimated. This information technology (IT) driven organisational change across the whole municipal environment represents the research topic and key objective of this research study, namely, a strategy towards implementing standard data structures in municipal IT systems. The study followed a pragmatic philosophy using diagnostic reasoning based on an inductive approach, multiple action research methods and a descriptive case study to derive the proposed implementation strategy. The research subjects, which included 25 pilot municipalities, were studied for the duration of the pilot implementation of the strategy with the objective of identifying and utilising the lessons learnt from their experience to fast track the rollout of the strategy to non-pilot municipalities. The study was limited to the local government environment and to South Africa as a geographic area and involved an accidental sample aligned to the implementation project under investigation. The proposed implementation strategy was, however, of a generic nature and is therefore applicable to any other institution or environment engaged in a similar implementation project. The main contribution of the study is an implementation strategy for standard data structures in municipal financial information systems and which consists of seven diagnostics, 17 guiding policies and 48 coherent actions. The strategy was developed and refined during six cycles of data collection, which were conducted at 25 municipalities actively involved in implementing of the standard data structures. The secondary contributions of the research study include three conference papers and one submission to an academic journal.
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  • Date Issued: 2020

A theory-based approach to evaluating a Continuing Teacher Professional Development Programme aimed at strengthening environment and sustainability education

  • Authors: Songqwaru, Nonyameko Zintle
  • Date: 2020
  • Subjects: Fundisa for Change , Environmental education -- South Africa , Teachers -- Training of -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/145267 , vital:38423
  • Description: This study uses a theory-based approach to evaluate the Fundisa for Change training programme, a continuing teacher professional development programme aimed at strengthening environment and sustainability education. The aim of the study was to surface assumptions that underpin the design and implementation of the Fundisa for Change training programme. The Fundisa for Change Teacher Education programme is a national collaborative programme that is implemented in all the nine provinces of South Africa. The study reports on the implementation of the programme in five provinces. The study aimed to surface the Fundisa for Change training programme’s implementation theory and programme theory as these affect programme delivery. The Fundisa for Change training programme was implemented in diverse contexts by different facilitators to different participants. To determine how training programme outcomes were achieved, use was made of context-mechanism-outcome (CMO) configurations for each site where the programme was implemented. Data used to construct CMO configurations was generated through document analysis of Fundisa for Change documents, interviews with stakeholders and participants, as well as observations of programme implementation at five sites. There were three phases to data analysis: content analysis of Fundisa for Change documents, content analysis of observation transcripts and use of the CMO configuration, an analytical tool used in realist evaluation. An initial CMO configuration was constructed prior to observing implementation of the programme and a refined CMO configuration for the Fundisa for Change training programme was constructed based on similarities between the CMO configurations constructed for each of the five sites under study. The partnership model of the Fundisa for Change training programme brought diverse expertise and resources (material, cognitive, social and emotional) which were conducive to the achievement of programme outcomes. The programme’s action context (structure, culture, agency and relations) contributed to the achievement of programme outcomes by participants. Participants’ subject content knowledge, teaching practice and assessment practice was enhanced through attending the Fundisa for Change training. On-course tasks were mediated during training and this created opportunities for participants to discuss and reflect on current practice in ways that could lead to a change in practice. In evaluating professional development programmes, an elaborated definition of context in terms of structure, culture, agency and relations enables a comprehensive exploration of potential programme mechanisms that can be activated when programmes are implemented. It is also important to disaggregate resources and reasons when identifying mechanisms as this assists with differentiating between context and mechanisms. The study offers insights into the professional learning of teachers grappling with new content and pedagogical content knowledges related to environment in the context of recent curriculum changes where the South African national school curriculum has come into focus. Environmental education programmes in South Africa have implicitly used a realist approach. This study offers the first substantive professional learning evaluation that develops this approach explicitly using Theory of Change and Realist Evaluation in combination.
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  • Date Issued: 2020

A trait-based approach to identify indicators for measuring rocky reef ecosystem condition in South Africa

  • Authors: Smit, Kaylee
  • Date: 2020
  • Subjects: Environmental management -- Evaluation , Environmental monitoring -- Methodology Marine ecology -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/49292 , vital:41618
  • Description: An important yet challenging task for effective ecosystem-based management of marine ecosystems is the reliable measurement and monitoring of changes in ecosystem condition. In South Africa, the National Biodiversity Assessment (NBA) has relied on cumulative pressure mapping, based on the calculation of cumulative impact scores, as a proxy for measures of marine ecosystem condition. While this method is practical for broad scale assessments where ecological data are lacking, there is a need to groundtruth this approach at local scales using in-situ data. The aim of this thesis was to identify potential indicators that can be used to measure the ecosystem condition of subtidal rocky reefs on the East coast of South Africa to groundtruth national pressure-based condition assessments. This thesis constituted the first attempt to conduct a comprehensive assessment of rocky reef ecosystem condition to validate national pressure-based assessments in South Africa. Based on a comprehensive literature review, a traits-based approach was selected to ensure that ecosystem structure and function were included in condition measurements. Fish and benthic community data were collected using baited remote underwater stereo-video systems (144 video samples) from the Natal Shelf ecoregion. Sampling spanned a gradient of low to high human pressures, which incorporated an effective Marine Protected Area (to define reference conditions), as well as areas exposed to intermediate levels of human pressures and a highly impacted area offshore of a large metropolitan port city. Structural and functional indicators were compared among localities and suitable functional indicators were aggregated into multimetric indices (MMIs) to provide an integrated measurement of ecosystem condition. Approximately 840 benthic biota and 10 400 fish (representing 176 identified fish species) were counted. Results showed that functional indicators, particularly size-based ones, were more effective at detecting changes in ecosystem condition compared with structural indicators based on taxonomy. Reefs in good ecological condition had a higher biomass of target species and a higher proportion of large predatory fish with more adults, compared with impacted areas. Benthic communities, however, appeared less responsive to cumulative pressures. The MMIs, using fish and benthic community data, were used to compare condition categories with those from the NBA. Results showed that the pressure-based assessments provided a reasonable proxy of broad patterns of rocky reef ecosystem condition. However, fine-scale discrepancies between results from the data-driven approach versus the proxy method suggested that broad-scale proxies might overestimate condition in some areas and underestimate it in others. To build on these results, the applicability of structural and functional indicators and MMIs were tested using an independent stereo-BRUVs dataset from the Agulhas Shelf ecoregion. Findings showed that not all MPAs were in good ecological condition compared with adjacent impacted areas, as was estimated by the NBA. However, there is a need to improve the quality of trait data and to test indicators and indices in other ecoregions, ecosystem types and in response to a broader range of improved pressure data. Furthermore, there is a need to apply innovative research to guide the calculation of thresholds for condition categories to advance condition assessments.
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  • Date Issued: 2020

A transportation management framework for the Polokwane local municipality during Zion Christian Church (ZCC) Easter weekend pilgrimage

  • Authors: Mathebula, Andrew Mabila
  • Date: 2020
  • Subjects: Transportation -- Management , Urban transportation -- Planning Urban transportation -- Management Christian pilgrims and pilgrimages
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/46152 , vital:39509
  • Description: The study investigated the impact of the high volume of vehicular traffic on pilgrims and the community during the Zion Christian Church (ZCC) Easter weekend pilgrimage. The researcher adopted an interpretivist research philosophy, and thus attempted to understand policy, planning, and management of the ZCC Easter pilgrimage through meanings that municipal officials assign to them. The study employed the action research approach by collaborating with the Polokwane Local Municipality (PLM) with a view to evolving lasting solutions to traffic congestion during the Easter weekend. The researchers used the seven-step model proposed by Van Tonder and Dietrichsen (Van Tonder and Dietrichsen, 2008). The justification of the model is that it is aligned with the action research model of Organisational Development (OD). It requires that a diagnosis process should be collaborative and participative towards offering solutions to organisational challenges as opposed to imposing a unilateral theoretical generated solution. This model also fits the ontological stance of the researchers which assumes that reality is co-constructed through engagement with other stakeholders. The researcher conducted semi-structured individual and focus groups discussion (FGD) using openended guides. The data from the informants were collected until a point of saturation. In addition to facilitation FGD discussion, the researcher made his own personal reflection of the participatory action research (PAR). A content analysis method was used to synthesise the qualitative data. The contents were extracted from transcribed interviews. The researcher carefully reviewed the notes several times and coded the notes independently. After that, the researcher coded the codes with each other for any potential contradiction. These codes were converted into themes and sub-themes. The qualitative content analysis process, led by the researcher, was both inductive and deductive. Prior to the inductive process, the researcher listened carefully to the audio recordings transcriptions to get a general understanding of participants’ experiences. The findings indicate that the South African transportation planning approach is ossified and divorced from reality. There is a lacuna to address peak traffic challenges during the Easter weekend and the festive season. It is notable that the government-led seasonal road safety campaigns such as ‘Arrive Alive’ are curiously inadequate to address peak traffic and road accidents challenges in South Africa during the ZCC Easter pilgrimage. The transportation management framework for the PLM as well as a peak traffic standard were developed as part of the study recommendations. These recommendations augur a shift to transport planning in South Africa.
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  • Date Issued: 2020

Activity of diverse chalcones against several targets: statistical analysis of a high-throughput virtual screen of a custom chalcone library

  • Authors: Sarron, Arthur F D
  • Date: 2020
  • Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/116028 , vital:34291
  • Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
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  • Date Issued: 2020

Addressing flux suppression, radio frequency interference, and selection of optimal solution intervals during radio interferometric calibration

  • Authors: Sob, Ulrich Armel Mbou
  • Date: 2020
  • Subjects: CubiCal (Software) , Radio -- Interference , Imaging systems in astronomy , Algorithms , Astronomical instruments -- Calibration , Astronomy -- Data processing
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/147714 , vital:38663
  • Description: The forthcoming Square Kilometre Array is expected to provide answers to some of the most intriguing questions about our Universe. However, as it is already noticeable from MeerKAT and other precursors, the amounts of data produced by these new instruments are significantly challenging to calibrate and image. Calibration of radio interferometric data is usually biased by incomplete sky models and radio frequency interference (RFI) resulting in calibration artefacts that limit the dynamic range and image fidelity of the resulting images. One of the most noticeable of these artefacts is the formation of spurious sources which causes suppression of real emissions. Fortunately, it has been shown that calibration algorithms employing heavy-tailed likelihood functions are less susceptible to this due to their robustness against outliers. Leveraging on recent developments in the field of complex optimisation, we implement a robust calibration algorithm using a Student’s t likelihood function and Wirtinger derivatives. The new algorithm, dubbed the robust solver, is incorporated as a subroutine into the newly released calibration software package CubiCal. We perform statistical analysis on the distribution of visibilities and provide an insight into the functioning of the robust solver and describe different scenarios where it will improve calibration. We use simulations to show that the robust solver effectively reduces the amount of flux suppressed from unmodelled sources both in direction independent and direction dependent calibration. Furthermore, the robust solver is shown to successfully mitigate the effects of low-level RFI when applied to a simulated and a real VLA dataset. Finally, we demonstrate that there are close links between the amount of flux suppressed from sources, the effects of the RFI and the employed solution interval during radio interferometric calibration. Hence, we investigate the effects of solution intervals and the different factors to consider in order to select adequate solution intervals. Furthermore, we propose a practical brute force method for selecting optimal solution intervals. The proposed method is successfully applied to a VLA dataset.
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  • Date Issued: 2020

An analysis of how visualisation capabilities in dynamic geometric software develop meaning-making of mathematical concepts in selected Grade 11 learners

  • Authors: Mavani, Deepack Pravin
  • Date: 2020
  • Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematics -- Computer programs , Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies , Mathematics -- Study and teaching -- Activity programs , Educational technology , Visualization
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/143213 , vital:38211
  • Description: Visualisation plays a central role in developing mathematical ideas because it can be used to make these ideas explicit and visible, and thus has the potential to advance understanding. This study centred around the GeoGebra Literacy Initiative Project (GLIP), a teacher development initiative in Mthatha that aimed to grow and develop appropriate Information and Communication Technology (ICT) skills in teachers, to harness the teaching and learning potential of GeoGebra. GeoGebra is a dynamic geometric software package that is very interactive and makes use of powerful features to create images which can be moved around the computer screen for mathematical exploration. This research project was located within GLIP and analysed how GeoGebra applets develop conceptual and procedural understanding in selected Grade 11 learners. One aspect of GLIP was for teachers to use GeoGebra applets that they had developed themselves and implemented in their classrooms in pre-determined cycles that were aligned to the curriculum. My study specifically focused on how the selected learners made use of these applets and explored how learning had taken place in terms of developing mathematical meaning-making. This interpretive research study was designed as a case study. The case was a cohort of selected Grade 11 learners who had been taught by GLIP teachers, and my unit of analysis was the learners’ interaction with the applets. A screen capturing software package was used to capture learners’ interactions with the GeoGebra. My data consisted mainly of recorded observations and interviews. An analytical framework derived from the works of Kilpatrick, Swafford, and Findell (2001) and Carter et al. (2009) guided and informed the data analysis of the learners’ activities with the GeoGebra. The theoretical orientation of this study was constructivist learning. An in-depth analysis and detailed descriptions of the participants’ interactions enabled me to gain a comprehensive understanding of their meaning-making processes in a technological classroom context. An analysis across the participants identified distinguishable patterns or differences in the development of the learners’ mathematical proficiency and making sense of mathematical ideas. The research argued that technology enabled visualisation was a powerful tool to not only enrich mathematically activities, but to also enrich conceptual and procedural understanding. The findings recognised that exploration of, or manipulation on mathematical objects in GeoGebra was a key activity in the participants’ meaning-making process. It also enabled learners to offer self-proclaimed theories
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  • Date Issued: 2020

An audience perception of pentecostal churches’ television programmes on star times and dstv in lagos, Nigeria

  • Authors: Olaoye, Adewale Titus
  • Date: 2020
  • Subjects: Religious broadcasting -- Christianity Television in religion Mass media in religion
  • Language: English
  • Type: Thesis , Doctoral , PhD (Communication)
  • Identifier: http://hdl.handle.net/10353/11418 , vital:39070
  • Description: Pentecostal churches in Nigeria are leveraging traditional and new media technologies such as cable or digital satellite television, to broadcast services and programmes to their regular and a growing community of virtual worshippers. Critics of this type of religious outreach now known as televangelism have challenged its predominant, if not exclusive focus on miracle and prosperity message. Using the mixed-method research design involving focus group discussions, key informant interviews and a survey of 255 respondents, this study sought to ascertain Lagos audiences‘ perceptions of Pentecostal Television programmes on two satellite stations, Start Times and DSTV. The findings revealed that audience members perceive Pentecostal churches programme as primarily focused on converting the audience members to the Christian faith. The result revealed that miracle sessions are a common feature of televangelism. Respondents see the miracles as manipulations largely intended to woo and often, hoodwink audience members. The findings revealed that although some of the Pentecostal churches‘ programmes dwell more on the word of God compared to the mainline churches, the programmes and teachings, however, often tended to promote the leadership of the church and not the gospel of Christ. Generally, the study indicates the majority of the audience members are aware of and identify with the atrocities the Pentecostal Churches are accused of perpetrating through their TV programmes. The findings revealed poor awareness and knowledge about the role of the Nigeria Broadcasting Corporation (NBC). The results suggest participants do not believe the NBC is living up to its responsibilities. The findings of this study highlight the need for the NBC, the Christian Association of Nigeria (CAN) and Pentecostal Fellowship of Nigeria (PFN) to work together in formulating new regulations for controlling religious broadcast on television, Pentecostal TV broadcasts, in particular. This is the only way to safeguard vulnerable members of the audience from being manipulated and brainwashed.
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  • Date Issued: 2020

An evaluation of programme management with reference to inner -city problem buildings: The case of Nelson Mandela Bay Metropolitan Municipality ,South Africa

  • Authors: Conradie, Hendrik Francois , Shaidi,Walter
  • Date: 2020
  • Subjects: Municipal government -- South Africa -- Port Elizabeth , Finance,Public --South Africa --Port Elizabeth
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/46670 , vital:39607
  • Description: This research study is qualitative and cross-sectional in nature. Programme management by South African city governments is investigated and evaluated, as related to inner-city decay and problem (derelict; hijacked; dilapidated; overcrowded) buildings. A case study approach, focusing on the Nelson Mandela Bay Municipality in Port Elizabeth, South Africa, is utilised to understand the phenomenon, and to answer the research question. The significant challenge of inner-city and central business district problem buildings in major South African cities has prompted the study; no scientific research has previously been conducted or published on this topic The study started out with this research question, asked in a case study context: to what extent are programmes dealing with inner-city problem buildings and decay managed effectively by city government in South Africa? In the literature review the researcher focused on programme management theory, emphasising the usefulness of project management principles and practice in public sector programme management contexts. In a subsequent chapter the applicable constitutional and legislative frameworks were presented. The researcher developed, as outcome, strategic remedial legal options available to city governments when dealing with transgressing owners of problematic buildings. Problem building by-laws were dealt with in detail. A qualitative research approach, including semi-structured in-depth interviews with political and managerial leaders at the case study city government, assisted the researcher in effective data generation. Data analysis was performed with vigour, based on thematic content analysis.relevant coding practices were utilised in analysis and interpretation of data.
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  • Date Issued: 2020

An examination of practices and experiences of teacher educators in the supervision of a national early childhood home based programme

  • Authors: Annatolia, Misi
  • Date: 2020
  • Subjects: Early childhood education -- Zimbabwe
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/49362 , vital:41695
  • Description: Zimbabwean teacher educators are, by the nature of their job description, required to supervise student teachers doing teaching practicum for the 0-3 home based programme. However, analysis of supervision reports of the home based programme indicates some inconsistencies in comments made by different supervisors, whereby the descriptors and supervision overall scores do not tally. It seems the supervision of the home based teacher education programme is not being implemented as expected. Hence, the purpose of this qualitative case study was to examine practices and experiences of teacher educators in the supervision of a National Early Childhood Development Home Based Teacher Education Programme (NECDHBTEP). The objective of the study was to address the key question: ‘What are the practices and experiences of teacher educators in the supervision of a NECDHBTEP. In addressing the question, the researcher used supervision as a conceptual framework. The theoretical framework which informed the study was Contextual Supervision (CS) which has its philosophical foundations in constructivism, beneficence and justice. Purposive sampling was employed in the study where two primary teachers’ colleges were selected. From each college, ten teacher educators were selected for semi-structured interviews, two focus group discussions and document analysis on teacher educators’ supervision reports. Triangulation of the data was done so as to enhance its trustworthiness. Three major themes emerged from the study, namely, the influence of home context, experience of supervisors on NECDHBTEP and supervision approaches. The study discovered that the home context, to some extent, influences supervision of the NECDHBTEP. The study also established that teacher educators face multiple challenges when supervising student teachers on the ECD home based programme. The researcher made some recommendations from the findings. One of the recommendations was for colleges to develop a specific supervision instrument for the home based ECD supervision (0-3 years category). Furthermore, there is need for Zimbabwean primary teachers’ colleges to engage in rigorous in-service training for lecturers who are not knowledgeable about the NECDHBTEP.
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  • Date Issued: 2020

An exploration of how Grade 3 Foundation Phase teachers develop basic scientific process skills using an inquiry-based approach in their classrooms

  • Authors: Nhase, Zukiswa
  • Date: 2020
  • Subjects: Elementary school teaching-- South Africa , Elementary school teachers -- South Africa , Elementary school teachers -- In-service training -- South Africa , Science -- Study and teaching (Elementary) -- South Africa , Learning, Psychology of , Cognition in children , Inquiry-based learning -- South Africa , Active learning -- South Africa , Pedagogical content knowledge -- South Africa , Educational change -- South Africa , Socio-cultural theory
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/145181 , vital:38416
  • Description: Some studies have looked at Foundation Phase teachers’ perspectives on the teaching of science in this phase. Such studies have highlighted various challenges on the teaching of science in the Foundation Phase. They pointed out issues such as large class numbers, lack of resources and lack of science knowledge from Foundation Phase teachers. However, none of these studies have looked at how Foundation Phase teachers are using an Inquiry-Based Approach in their classrooms instead few studies have looked at the Foundation Phase teachers’ perspectives about scientific inquiry in this phase. Even though many scholars have presented several challenges to the teaching of science both at secondary and primary level, the argument is strongly made that Foundation Phase learners should be exposed to the learning of science. Generally, children at the Foundation Phase level naturally enjoy observing and thinking about nature; exposing learners to science develops positive attitudes towards science; the use of scientifically informed language at an early age influences the eventual development of scientific concepts; children can understand scientific concepts and reason scientifically; and science is an efficient means for developing scientific thinking. It is within these arguments and discussions that this interpretive case study research sought to explore the Pedagogical Content Knowledge of four Foundation Phase teachers in developing the Scientific Process Skills using an Inquiry-Based Approach in their classrooms and subsequently, the significance of this research study. The socio-cultural theory, Topic Specific Pedagogical Content Knowledge, Zaretskii’s six conditions for development during mediation and the principles of an Inquiry-Based Approach were used as analytical lenses in this research. To use an Inquiry-Based Approach, generally teachers have to understand its principles and know how to develop basic Scientific Process Skills while teaching the science content. In the Foundation Phase, the Natural Sciences component or content is embedded in the Beginning Knowledge study area of the Life Skills subject and this can create difficulties for teachers to even recognise the scientific concepts in the Life Skills. The four IsiXhosa female teachers used the home language of learners as the language of instruction to implement an Inquiry-Based Approach in their classrooms. Data were generated in four phases. Phase one was baseline data through document analysis. Three of the phases were directed by the research question asked. Data were generated using questionnaires, interviews (semi-structured and stimulated recall), lesson observations (videotaped) and group reflections and discussions. From the work of Vygotsky, Zaretskii formulated six conditions that can be used to develop learners’ zone of proximal development in learning and these were used as analytical lenses to analyse data to understand how teachers mediated learning and development of Scientific Inquiry in their Grade 3 classrooms. In addition, the principles of an Inquiry-Based Approach were used as analytical lenses as to how teachers implemented the scientific inquiry approach. The categories or components of Topic Specific Pedagogical Content Knowledge were used as analytical lenses as to how these teachers dealt with science concepts or content when using an inquiry-based Approach in their classrooms. Using the home language of learners as an instructional tool, data showed that learners were afforded the opportunity to freely engage in activities and as a result, the context of learning was non-threatening for both teachers and learners. Although learning activities could be improved, teachers created social spaces for learners to take part in learning. In addition, the use of learners’ environments in the observed lessons made it comfortable for learners to act as young scientists. The new knowledge in this research was presented by the use of the adapted analytical tool, which combined diverse components of theory and literature that aligned with each other. The reflection space for the participants did not only afford the participants to discuss about each other’s lessons or experiences in this research, it allowed the participants to engage with the research objectives. The reflection space strengthened the research ethics if this study. Hence, the concept that says, ‘Absenting the absences’. In conclusion, the study thus recommends further professional development spaces that promote community of practice in using an Inquiry-Based Approach in the Foundation Phase.
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  • Date Issued: 2020

An integrative approach to understanding vulnerability of an alpine range-restricted bird to climate warming

  • Authors: Oswald, Krista Natasha
  • Date: 2020
  • Subjects: Passeriformes -- South Africa -- Western Cape , Passeriformes -- Physiology -- South Africa -- Western Cape , Passeriformes -- Behavior -- Climatic factors -- South Africa -- Western Cape , Passeriformes -- Reproduction -- Climatic factors -- South Africa -- Western Cape , Passeriformes -- Dispersal -- South Africa -- Western Cape , Passeriformes -- Food -- South Africa -- Western Cape , Passeriformes -- Nests-- South Africa -- Western Cape , Blue Hill Nature Reserve , Cape Rockjumper -- Climatic factors , Chaetops frenatus
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/148517 , vital:38746
  • Description: Understanding species' vulnerability to climate change requires an integrative ecological approach involving, at minimum, physiology, behaviour, reproductive success, and limitations on dispersal. In this thesis I determined potential negative effects of increasing temperatures on behaviour, reproduction, and ability to disperse in an alpine-restricted bird, the Cape Rockjumper Chaetops frenatus ("Rockjumper"). Here I provide a comprehensive ecological set of data for understanding the link between Rockjumper population declines and warming habitats. I tested whether Rockjumper microsite-use at high temperatures resulted in decreased time spent on important behaviours, such as foraging. I found Rockjumpers made increased use of rock-shade as air temperature increased and so spent less time panting, but birds in rock-shade foraged less. Birds may be constrained to foraging in sun at high temperatures to sustain energy or water requirements, despite risks of high thermal load, or else face lost foraging opportunities by remaining in rock-shade. I determined if adult nest attendance and causes of nest failure were related to high temperatures. I filmed nests over two breeding seasons to examine temperature-effects on adult time in nests, provisioning rate, and resultant nestling daily mass gain. The only temperature effect I found was decreased percent daily change in body mass for older nestlings at hotter temperatures. I also examined causes of nest failure over three breeding seasons in relation to nest concealment and habitat openness by observing failure/success. Nests in more open territories (i.e. early post-fire habitat) had greater success, and the main cause of predation came from Boomslang Dispholydus typus. Importantly, the probability of Boomslang predation increased significantly at hotter temperatures. These findings show there may be direct negative effects of increasing temperatures on reproductive success and population recruitment, and so hotter temperature during the breeding season may be at least partly responsible for observed population declines. Lastly, I examined genetic structure of populations across mountain ranges separated from one another by lowland habitat unsuitable for Rockjumpers. I predicted I would find little evidence for dispersal between mountain ranges separated by unsuitable lowland habitat, but instead found Rockjumpers show little evidence for inbreeding. I also found evidence for a past bottleneck event or founder effect, and little overall genetic diversity (possibly as their specialized niche exerts selective pressure). Low diversity may limit Rockjumpers' ability to adapt to a changing environment. Adult physiological and behavioural thresholds to increasing temperatures are often used to create predictions of climate change effects. My past physiological research and current behavioural research suggest no particularly strong evidence that temperature-related population declines are driven by poor physiological capacity to tolerate heat or negative behaviour trade-offs. Instead, my current research shows that understanding negative effects of increasing temperatures may require a more in-depth approach involving investigation of fine-scale ecological interactions. No single one of my chapters provides the insight necessary for understanding Rockjumper population declines at warming temperatures. Instead, I show how an integrative approach may be necessary for assessing species' vulnerability to climate change by examining multiple ecological aspects of a single sentinel species, using an alpine species with a narrow thermal range and highly specialized habitat niche.
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  • Date Issued: 2020

An intervention on supporting teachers’ understanding of and mediation of learning of stoichiometry in selected schools in the Zambezi Region

  • Authors: Denuga, Desalu Dedayo
  • Date: 2020
  • Subjects: Stoichiometry -- Study and teaching (Secondary) -- Namibia , Chemistry -- Study and teaching (Secondary) -- Namibia , Participant observation -- Namibia , Constructivism (Education) -- Namibia , Pedagogical content knowledge -- Namibia , Continuing education -- Namibia , Teachers -- In-service training -- Namibia
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/103855 , vital:32315
  • Description: This study has been triggered by the results on stoichiometry questions in the Directorate of Namibian Examination Assessment’s (DNEA) scripts. As highlighted in the examiners’ reports, stoichiometry is an ongoing annual problem for most students in Namibia. It is against this background that I decided to explore the possibility of an intervention in the form of continuing professional development (CPD) and collaboration workshops to improve the understanding and the mediation of learning of stoichiometry by Physical Science teachers in the Zambezi Region of Namibia. The study was underpinned by an interpretive paradigm and within this paradigm a qualitative case study approach was adopted. Since this study was in a form of an intervention, a participatory action research (PAR) approach was employed within the community of practice (CoP). I used document analysis, workshop discussions, observations and videotaped lessons, interviews (semi-structured and stimulated recall interviews) and reflections to gather data. The study was carried out at three senior secondary schools and six Physical Science teachers were involved. The study drew on the theory of constructivism as a theoretical framework, namely, Piaget’s cognitive constructivism and Vygotsky‘s social constructivism as well as Shulman’s pedagogical content knowledge (PCK). Within PCK, Mavhunga and Rollnick’s Topic Specific Pedagogical Content Knowledge (TSPCK) was used as an analytical lens (Appendix L) in this study. The findings reveal that the use of a diagnostic test on learners made the Physical Science teachers aware of the learners’ challenges and what was difficult for them to understand in stoichiometry. It also helped in their understanding of the use of prior knowledge, one of the tenets of TSPCK, to access what learners knew about stoichiometry. Further findings of the study illuminate that the Physical Science teachers’ subject matter knowledge, pedagogical content knowledge and skills had shifted as a result of their participation in the intervention workshops. The findings of this study indicate that the CoP members acquired the professional transformations which were important breakthroughs in their careers. The study thus recommends that teachers should develop effective teacher professional development activities such as study teams, exemplary lessons, cluster teaching, and peer coaching where teachers are expected to examine their assumptions and practices continuously. The implication of my study is that the developed exemplary lesson during the intervention workshops by CoP members could be useful to other Physical Science teachers in the teaching of stoichiometry in all the schools in the Zambezi Region.
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  • Date Issued: 2020

An investigation into the nature and adequacy of tax compliance tools available to assist small businesses in the state of Oklahoma in the United States of America

  • Authors: Cary, Cindi L
  • Date: 2020
  • Subjects: Tax administration and procedure -- United States , United States. Internal Revenue Service , Small business -- Oklahoma , Small business -- United States , Taxpayer compliance -- Oklahoma , Taxpayer compliance -- United States
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/141015 , vital:37937
  • Description: This study identifies and analyses the effectiveness of the tax tools available to the small businesses that make up more than 99 per cent of all businesses in the United States and the state of Oklahoma through an extensive investigation of the small business resources offered by federal and state government agencies, higher education institutions and the professional accounting community. The study uses numerous measurements in order to acquire multiple perspectives and relies on the examination of government websites and documents, interviews, experiments, surveys, and questionnaires to determine the existing small business tax tools and their limitations. The research offers an in-depth analysis of the facts and limitations of the small business services offered by the Internal Revenue Service (IRS). The IRS is determined the largest source of small business tax tools, but limitations plague their effectiveness. Higher education is found guilty of not providing small business education in business or accounting disciplines, leaving college graduates ill-prepared to assist small businesses. Higher education is urged to implement a small business accounting curriculum that couples field experience with classroom lectures and textbooks. This study finds the accounting profession apathetic with regard to informing small businesses of accounting services and presses certified public accountants to be more involved in the education of future small business accountants. The study concludes with recommendations to reduce the small business tax burden by improving the existing small business tax tools.
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  • Date Issued: 2020

An investigation of the experiences of psychotherapists regarding Ubuntu in their psychotherapy practice: an interpretative phenomenological analysis

  • Authors: Qangule, Lumka Sybil
  • Date: 2020
  • Subjects: Ubuntu (Philosophy) , Psychotherapy -- Cross-cultural studies , Psychoanalysis and culture -- South Africa , Xhosa (African people) -- Psychology , Xhosa (African people) -- Mental health , Black people -- South Africa -- Psychology , Black people -- South Africa -- Mental health , Psychotherapists -- South Africa
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/146923 , vital:38577
  • Description: Psychotherapy is a Eurocentric concept and practice that has migrated to South Africa with technology, as part of the general transfer of knowledge (Mkhize, 2003). It has embedded Eurocentric principles that sometimes do not easily accommodate working with Africans. It has been practised by psychotherapists of African origin with clients of African origin, but is based upon Eurocentric ideas and guidelines for practice. Many African people consider their core values to be uBuntu, rooted in a principle ‘umntu ngumntu ngabantu’ (translated as ‘a human being is a human being because of other human beings’). Some important features of uBuntu are interdependence, respect, spirituality and the primacy of communality as an approach to life. Some of the ways in which these impact on daily functioning are not foregrounded by adherence to Western principles. The use of only Eurocentric principles when working with clients of African origin may thus not lead to the desired outcomes in psychotherapy. However, these Eurocentric principles are recognised and enforced by the authoritative bodies in the field of psychology, such as the Health Professions Council of South Africa. A distinction will be made between the more inflexible ethical principles of psychology and the ideas of therapy frames. Therapy frames are not seen as being as rigid as ethical codes and they could be augmented, to be appropriate for the context, particularly in the commonly multicultural settings that are found here. Psychotherapists of African origin are torn between abiding by the ethical principles that they have been taught and practising in the way that they, together with their clients, have been socialised. Abiding by the principles as described in the codes is safe because it does not pose any threat of being sanctioned by the regulator of practice, but clients may be let down and there may be limited success with certain clients. This clash of ideas of ways of practice poses dissonance and many dilemmas among psychotherapists of African origin. Due to the nature of this study, Interpretative Phenomenological Analysis (IPA) was adopted as a suitable methodology, where eight practising amaXhosa psychotherapists were interviewed about their experiences of incorporating uBuntu in their psychotherapy practice. The raw data from initial interviews were analysed and the findings concluded that although psychotherapists were trained in Western ways of practice, they included some practices of uBuntu in their practice as well as upholding some Eurocentric principles that seemed to be helpful for their clientele. Subsequently a summary of the findings were discussed with participants in a focus group setting, where participants endorsed and expanded upon their original responses. With the above in mind, a psychotherapy model called uBuntu-Centred Psychotherapy was created, which reflects the principles and therapy frames that have been found to be useful in treating clients of African origin. This modality is more congruent with the worldviews and style of living of many South Africans, in the post-apartheid era. It embraces some Eurocentric principles that are relevant for Africans, while it is embedded in the phenomena and way of life reflected in uBuntu, a predominant mode of functioning for the group that was the focus of this study, the amaXhosa. The study ends by making recommendations for practice, as well as highlighting the need for further and more extensive research to contribute to the project of Africanising psychotherapy.
  • Full Text:
  • Date Issued: 2020
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