List of Titles

Quick View

Alcohol use among women attending antenatal care in Buffalo City, Eastern Cape

- Bredenkamp, Petrus Johannes

Authors: Bredenkamp, Petrus Johannes
Date: 2022-04-07
Subjects: Uncatalogued
Language: English
Type: Master's thesis , text
Identifier: http://hdl.handle.net/10962/234358 , vital:50188
Description: Alcohol use during pregnancy is known to cause neurodevelopmental disorders in offspring, known as Fetal Alcohol Spectrum Disorders (FASD). High prevalence of FASD has been observed in certain parts South Africa, but many areas of the country remain unstudied, and factors contributing to drinking among pregnant women are poorly understood. This study surveyed 1099 women attending antenatal care at public primary healthcare facilities in the Buffalo City Metropolitan Area in the Eastern Cape. Data was collected using the Alcohol Use Identification Test, a 10-item self-report measure of drinking behaviour in isiXhosa, English, and Afrikaans. Factors associated with alcohol use, risky drinking, binge drinking, and hazardous/harmful drinking were identified using logistic regression. A minority of the sample reported alcohol use (64%). Among those reporting alcohol use, most reported occasional binge drinking (63%) and met criteria for risky drinking (59%) and hazardous/harmful drinking (52%). Living with a regular drinker was significantly associated with alcohol use (OR 1.98, 95% CI 1.51 – 2.58), risky drinking (OR 2.03, 95% CI 1.49 – 2.76), binge drinking (OR 2.21, 95% CI 1.64 – 2.97), and hazardous/harmful drinking (OR 2.0, 95% CI 1.41 – 2.99). However, women who were married/cohabiting were less likely to report alcohol use (OR .71, 95% CI .53 - .95). Experiencing intimate partner violence during the current pregnancy was associated with alcohol use (OR 2.42, 95% CI 1.38 – 4.27) and hazardous/harmful drinking (OR 2.62, 95% CI 1.32 – 5.22). In this study, women who identified as Coloured were more likely to report alcohol use than Women who identified as African (OR 2.74, 95% CI 1.4 – 5.36). These findings simultaneously provide evidence of problematic drinking among pregnant women in a previously understudied area and show that external factors affect women’s drinking behaviour during pregnancy. Interventions aimed at reducing the incidence of FASD should consider alcohol use by pregnant women in the context of their lived experiences. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
Full Text:
Date Issued: 2022-04-07

Quick View

An investigation of the role of mitochondrial STAT3 and modulation of Reactive Oxygen Species in adipocyte differentiation

- Kramer, Adam Hildyard

Authors: Kramer, Adam Hildyard
Date: 2014
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/54632 , vital:26595
Description: Stem cells have the ability to differentiate into a myriad of different cell types. The understanding of the differentiation process is of paramount importance if we are to use these cells in the lab as well as in therapeutics. Here, the levels and localization of the signal transducer and activator of transcription 3 (STAT3), with particular attention focused on the mitochondrial serine 727 phosphorylated form of STAT3 (pSTAT3S727) during differentiation, was investigated. Using the murine preadipocyte progenitor cell line 3T3-L1, as well as adipose derived human mesenchymal stem cells (HMSC-ad) as differentiation models, the relative levels of Reactive Oxygen Species (ROS) and the levels and localization of STAT3 were investigated during the differentiation process. ROS is known to play an important signalling role during differentiation and is well reported during the events of adipogenesis. ROS are generated as a by-product in the Electron Transport Chain (ETC), and it has recently been reported that pSTAT3S727 plays an important role at complex I of the ETC. Various techniques including fluorescence confocal microscopy, flow cytometry and Western blots were utilized to investigate the non-canonical role STAT3 plays during adipogenesis. Mitochondrial isolations were performed to investigate the levels of STAT3 in the mitochondria during differentiation. Further to this, an impedance based real time differentiation assay was developed using the xCELLigence Real Time Cell Analyser to monitor differentiation and the affects various compounds, including a STAT3 inhibitor, have on differentiation. Results indicate that upon induction of differentiation, levels of mitochondrial pSTAT3S727 dramatically decrease and leave the mitochondria. This corresponds to increasing levels of ROS. The canonical active form of STAT3 following phosphorylation on tyrosine 705 (pSTAT3Y705) was found to decrease and lose its nuclear localization. These initial results indicate that STAT3 plays an important non-canonical role in the mitochondria during differentiation.
Full Text:
Date Issued: 2014

Quick View

Catchment and River Management in Graduate Teacher Education: A Case Study of Student Teacher Learning and Teaching in the Upper uThukela Valley, KwaZulu-Natal

- Heath, Gavin Edward Craig

Authors: Heath, Gavin Edward Craig
Date: 2021-10-29
Subjects: Geography Study and teaching (Higher) South Africa KwaZulu-Natal , Watershed management Study and teaching (Higher) South Africa KwaZulu-Natal , Pedagogical content knowledge , Environmental education South Africa KwaZulu-Natal , Teacher effectiveness South Africa KwaZulu-Natal , Curriculum and Assessment Policy Statement (CAPS)
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10962/190635 , vital:45012 , 10.21504/10962/190635
Description: This study developed as a progressive focus on a design research process towards the inclusion of new environmental knowledge in teacher education. It is centred on the clarification of pedagogical content knowledge for the teaching of catchment and river management in Geography teacher education. The study was developed as a design research case study with three phases or iterations of experiential engagement and data collection during the teaching of Postgraduate Certificate in Education students at the University of KwaZulu-Natal where I lecture Geography Education. The study’s iterative design was developed around pedagogical content knowledge refinement with curriculum knowledge analysis (phase 1) that was followed by lecture delivery and analysis (phase 2) and analysis of student engagement during fieldwork, and on teaching practice in rural classroom contexts (phase 3). Data and insights were generated across the successive stages of knowledge differentiation and teaching and learning interactions over time, and included reflection with students involved in the lectures, fieldwork and teaching practice programme. The analytical work covered a review of trajectories in new environmental knowledge, social-ecological systems, sustainability competencies, practice architecture and fieldwork pedagogy. This was done using three research lenses, namely social-ecological systems, social learning and practice architectures. All the design research and review processes served to develop, clarify and refine pedagogical content knowledge for sustainability-oriented teacher education. Thus the study conformed to the tenets of design-based research that was centred on clarification and review of pedagogical content knowledge that was carried into phases two and three. Research was focused at the nexus of pedagogical content knowledge and sustainability concerns that is necessary for the teaching of catchment and river basin management within a social-ecological systems perspective for integrated water resources management in South Africa and globally. The findings informed an illustrative model on how the research was carried out. Six design research insights and principles conclude the study and encapsulate the contribution it makes to new knowledge on how teacher education practice can be progressively aligned with new content knowledge teaching and the teaching of sustainability concerns. Specific findings in the form of six research insights indicated that the fieldworkbased teaching practice experience proved a successful learning crucible to develop sustainability competences. The cohort of student teachers passed their fieldwork teaching practice despite inadequate covering of foundational concepts in school and university. The teaching of a catchment management strategy case study was valuable in all three phases of research. A multi-contextual teaching and learning environment was successfully negotiated and navigated by the student teachers. The present Curriculum and Assessment Policy Statement does not speak to the reality on the ground, particularly in deep rural environments. A compulsory virtual Geography teacher training experience is recommended. Lastly, varied and broad responses to the noted multi-contextual challenges are needed in order to prepare and equip student teachers for the demands of the new environmental knowledge in the curriculum. Based on the groundwork provided by this study, there is scope for further research especially regarding the varied and broad responses to this new environmental knowledge in the curriculum. , Thesis (PhD) -- Faculty of Education, Education, 2021
Full Text:
Date Issued: 2021-10-29

Quick View

Exploring a shift in teacher practices after going through an intervention on the integration of local knowledge in grade 9 physical science lessons

- Mika, Rauha T

Authors: Mika, Rauha T
Date: 2019
Subjects: Physical sciences -- Study and teaching (Secondary) -- Namibia , Ethnoscience -- Study and teaching -- Namibia , Science -- Study and teaching (Secondary) -- Namibia , Curriculum planning -- Study and teaching -- Namibia
Language: English
Type: text , Thesis , Masters , MEd
Identifier: http://hdl.handle.net/10962/96801 , vital:31323
Description: It has been advocated by many scholars that the integration of local or indigenous knowledge into science classrooms might make science more relevant and accessible to learners, particularly in culturally diverse classrooms. As a result, the Namibian Grade 9 Physical Science curriculum expects teachers to integrate learners’ local or indigenous knowledge in their science classrooms. Despite these ideals, there are no clear instructions on how to go about doing this. This is exacerbated in part by the poor or lack of continuing professional development for science teachers. It is against this background that this study sought to explore an intervention on the integration of local or indigenous knowledge in Grade 9 Physical Science lessons. The study is underpinned by an interpretive paradigm and is informed by Vygotsky’s socio-cultural theory and Wenger’s community of practice. Within the interpretive paradigm, a qualitative case study approach was employed. It was carried out in four schools with four Physical Science teachers from Otjiwarongo circuit in Namibia. Qualitative data were generated using workshop discussions, document analysis, semi-structured interviews, classroom observations and reflections. A variety of data generation techniques were used for triangulation and validity purposes. Data were subsequently analysed inductively to come up with themes. The findings of the study revealed that before the intervention the teachers involved in this study had little knowledge about the integration of local or indigenous knowledge in science lessons. However, after their voluntary participation in the intervention, they were enabled to develop and mediate model lessons that integrated local or indigenous knowledge in their classrooms which their learners subsequently found to be stimulating. The findings of the study further revealed that integrating local or indigenous knowledge in science lessons had the potential to promote active participation by learners and foster learning using easily accessible resources. The study thus recommends that teachers should, where possible, strive to integrate learners’ local or indigenous knowledge in science lessons.
Full Text:
Date Issued: 2019

Quick View

Appraising the appraisal framework: evidence from Grahamstown property advertisements

- Beangstrom, Tracy

Authors: Beangstrom, Tracy
Date: 2015
Language: English
Type: text , Thesis , Masters , MA
Identifier: http://hdl.handle.net/10962/54744 , vital:26608
Description: This thesis considers how interpersonal meaning choices in property advertisements are best reflected in a context of constraint in Grahamstown, South Africa, using and appraising Martin & White’s (2005) APPRAISAL Framework. The study is comparative in two senses since the data is analysed using Martin & White’s (2005) APPRAISAL Framework and a revision to it, and property advertisements from two competing estate agencies are analysed: Remax Frontier Properties and Pam Golding Properties. An initial strict application of Martin & White’s (2005) framework is followed by a second, based on analyst difficulties and framework limitations experienced in the first analysis, as well as those experienced by other researchers. Revisions to the original framework include added ‘local’, context-driven features and sub-categories: Exclusivity and Convenience in Attitude, a Scale of Intensity in Graduation, and a category ‘Invite’ in Engagement. These enable a richer, more detailed account of the alignment strategies and interpersonal micro-politics at play in the property advertisements than is possible using the original framework. Findings from the analyses reveal four facts of note. Firstly, that while the original Martin & White (2005) APPRAISAL Framework captures a general level of interpersonal meaning in the data, it does so more fully when it includes contextual and contextually-driven categories that are informed by local knowledge. Secondly, two levels of meaning are expressed in the data. One is aimed at an ‘external’ audience; the other, truer, fuller and more contentious, is aimed at what appears to be the intended audience only. Thirdly, and relatedly, specific contextual and cultural knowledge is needed by the intended audience to access the intended meaning. Fourthly, both estate agencies promote values of high prestige, exclusivity, elitism and wealth as their intended meaning to align a like-minded audience, although Remax Frontier Properties attribute these values to location and features of the home to a greater extent than Pam Golding Properties, who place greater emphasis on the size of the home. The thesis suggests further avenues for research into the discourse of property advertising, as well as into overcoming certain context-specific limitations of the APPRAISAL Framework.
Full Text:
Date Issued: 2015

Quick View

The thermal physiology of Stenopelmus rufinasus and Neohydronomus affinis (Coleoptera: Curculionidae), biological control agents for the invasive alien aquatic weeds Azolla filiculoides and Pistia stratiotes respectively

- Mvandaba, Sisanda F

Authors: Mvandaba, Sisanda F
Date: 2018
Subjects: Beetles -- South Africa , Curculionidae -- South Africa , Azolla filiculoides -- South Africa , Water lettuce -- South Africa , Aquatic weeds -- Biological control -- South Africa , Stenopelmus rufinasus , Neohydronomus affinis
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/62362 , vital:28158
Description: Water lettuce, Pistia stratiotes L. (Araceae), and red water fern, Azolla filiculoides Lam. (Azollaceae), are floating aquatic macrophytes that have become problematic invaders in numerous South African waterbodies. Two weevils, Neohydronomus affinis Hustache 1926 (Coleoptera: Curculionidae) and Stenopelmus rufinasus Gyllenhal 1936 (Coleoptera: Curculionidae), are successful biological control agents of these two species, respectively, in South Africa. However, nothing is known about the thermal physiology of these two species Therefore, the aim of this study was to investigate the thermal physiologies of these two species to explain their establishment, distribution and impact in the field. Laboratory based thermal physiology trials showed that both weevils were widely tolerant of cold and warm temperatures. The CTmin of N. affinis was determined to be 5.5 ± 0.312°C and the CTmax was 44 ± 0.697°C, while the CTmin of S. rufinasus was 5.4 ± 0.333°C and the CTmax was 44.5 ± 0.168°C. In addition, the lower lethal temperatures were -9.8 ± 0.053°C and -7.2 ± 0.19°C, and the upper lethal temperatures were 42.8 ± 0.053°C and 41.9 ± 0.19°C respectively. These results suggest that both species should not be limited by cold winter temperatures, as previously thought. This is evident in the field, where S. rufinasus has established widely on A. filiculoides, despite local cold climates in some areas of the plant’s distribution. Even though N. affinis has a similar thermal range, and should therefore theoretically reflect a similar distribution to S. rufinasus throughout South Africa, its distribution is limited by the range of its host, which is restricted to the warmer regions of the country, as is its biocontrol agent. Using the reduced major axis regression method, the development for N. affinis was described using the formulay=12.976x+435.24, while the development of S. rufinasus was described by y=13.6x+222.45. These results showed that S. rufinasus develops much faster, in fact almost twice as quickly, than N. affinis. Using these formulae and temperature data obtained from the South African Weather Service, N. affinis was predicted to complete between 4 and 9 generations per year in South Africa, while S. rufinasus was predicted to complete between 5 and 14 generations per year around the country. This study showed that although the native range of these two species is warm temperate to tropical, they possess sufficient thermal plasticity to not only establish, but also damage their respective host plants in far cooler climates. Thus, in South Africa N. affinis and S. rufinasus are limited by the distribution of their target weeds and not climate.
Full Text:
Date Issued: 2018

Quick View

Constraining simulation uncertainties in a hydrological model of the Congo River Basin including a combined modelling approach for channel-wetland exchanges

- Kabuya, Pierre Mulamba

Authors: Kabuya, Pierre Mulamba
Date: 2021-04
Subjects: Congo River Watershed , Watersheds -- Congo (Democratic Republic) , Hydrologic models , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Wetland hydrology
Language: English
Type: thesis , text , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/177997 , vital:42897 , 10.21504/10962/177997
Description: Compared to other large river basins of the world, such as the Amazon, the Congo River Basin appears to be the most ungauged and less studied. This is partly because the basin lacks sufficient observational hydro-climatic monitoring stations and appropriate information on physiographic basin properties at a spatial scale deemed for hydrological applications, making it difficult to estimate water resources at the scale of sub-basins (Chapter 3). In the same time, the basin is facing the challenges related to rapid population growth, uncontrolled urbanisation as well as climate change. Adequate quantification of hydrological processes across different spatial and temporal scales in the basin, and the drivers of change, is essential for prediction and strategic planning to ensure sustainable management of water resources in the Congo River Basin. Hydrological models are particularly important to generate the required information. However, the shortness of the available streamflow records, lack of spatial representativeness of the available streamflow gauging stations and the lack of understanding of the processes in channel-wetland exchanges, are the main challenges that constrain the use of traditional approaches to models development. They also contribute to increased uncertainty in the estimation of water resources across the basin (Chapter 1 and 2). Given this ungauged nature of the Congo River Basin, it is important to resort to hydrological modelling approaches that can reasonably quantify and model the uncertainty associated with water resources estimation (Chapter 4) to make hydrological predictions reliable. This study explores appropriate methods for hydrological predictions and water resources assessment in ungauged catchments of the Congo River Basin. In this context, the core modelling framework combines the quantification of uncertainty in constraint indices, hydrological modelling and hydrodynamic modelling. The latter accounts for channel-wetland exchanges in sub-basins where wetlands exert considerable influence on downstream flow regimes at the monthly time scale. The constraint indices are the characteristics of a sub-basin’s long-term hydrological behaviour and may reflect the dynamics of the different components of the catchment water balance such as climate, water storage and different runoff processes. Currently, six constraint indices namely the mean monthly runoff volume (MMQ in m3 *106), mean monthly groundwater recharge depth (MMR in mm), the 10th, 50th and 90th percentiles of the flow duration curve expressed as a fraction of MMQ (Q10/MMQ, Q50/MMQ, Q90/MMQ) and the percentage of time that zero flows are expected (%Zero), are used in the modelling approach. These were judged to be the minimum number of key indices that can discriminate between different hydrological responses. The constraint indices in the framework help to determine an uncertainty range within which behavioural model parameters of the expected hydrological response can be identified. Predictive equations of the constraint indices across all climate and physiographic regions of the Congo Basin were based only on the aridity index because it was the most influential sub-basin attribute (Chapter 5) for which quantitative information was available. The degree of uncertainty in the constraint Q10/MMQ and Q50/MMQ indices is less than 41%, while it is somewhat higher for the mean monthly runoff (MMQ) and Q90/MMQ constraint indices. The established uncertainty ranges of the constraint indices were tested in some selected sub-basins of the Congo Basin, including the Lualaba (93 sub-basins), Sangha (24 sub-basins), Oubangui (19 sub-basins), Batéké plateaux (4 sub-basins), Kasai (4 sub-basins) and Inkisi (3 sub-basins). The results proved useful through the application of a 2-stage uncertainty approach of the PITMAN model. However, it comes out of this study that the application of the original constraint indices ranges (Chapter 5) generated satisfactory simulation results in some areas, while in others both small and large adjustments were required to fully capture some aspects of the observed hydrological responses (Chapter 6). Part of the reason is attributed to the availability and quality of streamflow data used to develop the constraint indices ranges (Chapter 5). The main issue identified in the modelling process was whether the changes made to the original constraints at headwater-gauged sub-basins can be applied to ungauged upstream sub-basins to match the observed flow at downstream gauging stations. Ideally, only gauged sub-basin’s constraints can be easily revised based on the observed flow. However, the refinement made to gauged sub-basins alone may fail to substantially affect the results if ungauged upstream sub-basins exert a major impact on defining downstream hydrological response. The majority of gauging stations used in this analysis are located downstream of many upstream ungauged sub-basins and therefore adjustments were required in ungauged sub-basins. These adjustments consist of shifting the full range of a constraint index either towards higher or lower values, depending on the degree to which the simulated uncertainty bounds depart from the observed flow. While this modelling approach seems effective in capturing many aspects of the hydrological responses with a reduced level of uncertainty compared to a previous study, it is recommended that the approach be extended to the remaining parts of the Congo Basin and assessed under current and future development conditions including environmental changes. A 2D hydrodynamic river-wetland model (LISFLOOD-FP) has been used to explicitly represent the inundation process exchanges between river channels and wetland systems. The hydrodynamic modelling outputs are used to calibrate the PITMAN wetland sub-model parameters. The five hydrodynamic models constructed for Ankoro, Kamalondo, Kundelungu, Mweru and Tshiangalele wetland systems have been partially validated using independent estimates of inundation extents available from Landsat imagery. Other sources of data such as remote sensing of water level altimetry, SAR images and wetland storage estimates may be used to improve the validation results. However, the important objective in this study was to make sure that flow volume exchanges between river channels and their adjacent floodplains were being simulated realistically. The wetland sub-model parameters are calibrated in a spreadsheet version of the PITMAN wetland routine to achieve visual correspondence between the LISFLOOD-FP and PITMAN wetland sub-model outputs (Storage volumes and channel outputs). The hysteretic patterns of the river-wetland processes were quantified using hysteresis indices and were associated with the spill and return flow parameters of the wetland sub-model and eventually with the wetland morphometric characteristics. One example is the scale parameter of the return flow function (AA), which shows a good relationship with the average surface slope of the wetland when the coefficient parameter (BB) of the same function is kept constant to a value of 1.25. The same parameter (AA) is a good indicator of the wetland emptying mechanism. A small AA indicates a wetland that slowly releases its flow, resulting in a highly delayed and attenuated hydrological response in downstream sub-basins. This understanding has a practical advantage for the estimation of the PITMAN wetland parameters in the many areas where it is not possible, or where the resources are not available, to run complex hydrodynamic models (Chapter 7). The inclusion of these LISFLOOD-FP informed wetland parameters in the basin-scale hydrological modelling results in acceptable simulations for the lower Lualaba drainage system. The small wetlands, like Ankoro and Tshiangalele, have a negligible impact on downstream flow regimes, whereas large wetlands, such as Kamalondo and Mweru, have very large impacts. In general, the testing of the original constraint indices in the region of wetlands and further downstream of the Lualaba drainage system has shown acceptable results. However, there remains an unresolved uncertainty issue related to the under and over-estimation of some aspects of the hydrological response at both Mulongo and Ankoro, two gauging stations in the immediate downstream of the Kamalondo wetland system. It is difficult to attribute this uncertainty to Kamalondo wetland parameters alone because many of the incremental sub-basins contributing to wetland inflows are ungauged. The issue at Mulongo is the under simulation of low flow, while the high flows at the Ankoro gauging station are over-simulated. However, the pattern of the calibrated constraint indices in this region (Chapter 8) shows that the under simulation of low flow at Mulongo cannot be attributed to incremental sub-basins (between Bukama, Kapolowe and Mulongo gauging stations), because their Q90/MMQ constraint indices are even slightly above the original constraint ranges, but maintain a spatial consistency with sub-basins of other regions. Similarly, sub-basins located between Mulongo, Luvua and Ankoro gauging stations have high flow indices slightly below the original constraint ranges and therefore they are unlikely to be responsible for the over simulation of high flow at the Ankoro gauging station. These facts highlight the need for a further understanding of the complex wetland system of Kamalondo. Short-term data collection and monitoring programme are required. Important tributaries that drain to this wetland need to be monitored by installing water level loggers and periodically collecting flow data and river bathymetry. This programme should lead to the development of rating curves of wetland input tributaries. This would partially solve the unresolved uncertainty issues at the Ankoro and Mulongo gauging stations. The integrated modelling approach offers many opportunities in the Congo Basin. The quantified and modelled uncertainty helps to identify regions with high uncertainty and allows for the identification of various data collection and management strategies that can potentially contribute to the uncertainty reduction. The quantified channel-wetland exchanges contribute to the improvement of the overall knowledge of water resources estimation within the regions where the effects of wetlands are evident even at the monthly time scale. In contrast, ignoring uncertainty in the estimates of water resources availability means that water resources planning and management decisions in the Congo Basin will continue to be based on inadequate information and unquantified uncertainty, thus increasing the risk associated with water resources decision making. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
Full Text:
Date Issued: 2021-04

Quick View

Knowledge practices and student access and success in General Chemistry at a Large South African University

- Mtombeni, Thabile Nokuthula

Authors: Mtombeni, Thabile Nokuthula
Date: 2018
Subjects: Chemistry -- Study and teaching (Higher) -- South Africa , Knowledge management , Education, Higher -- Curricula -- South Africa , Critical realism , Social integration -- South Africa , Educational equalization -- South Africa
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/62873 , vital:28305
Description: This dissertation reports on an investigation into the structuring principles of the General Chemistry curriculum at a Large South African University (LSAU). Student learning in the introductory modules of General Chemistry is critical for access to a range of fields since it is a requisite course for a variety of degree programmes. However, there is ample evidence that success in this subject remains a major challenge, particularly for black students. My quest in this study was to explore how the curriculum could enable greater epistemic access and thus include more students in science programmes at the LSAU. I investigated the organising principles underlying the curriculum practices of the General Chemistry module and explored the effects of the curriculum structure on student learning. Theoretically and conceptually, the study was underpinned by a social realist approach which holds that knowledge is stratified, differentiated, and has real emergent properties, powers and effects. The research question that I attempted to answer in this study was: How do knowledge practices privileged in the General Chemistry curriculum at the LSAU enable or constrain student learning? I adopted an intensive research design approach to conduct a qualitative case study using social realism and LCT as theoretical and analytical lenses. I used empirical data such as curriculum documents and interviews with lecturers to uncover the underlying generative mechanisms of the curriculum. I adopted a multi-layered data analysis process to make visible the underlying organising principles informing knowledge practices in the curriculum so that I could explain their potential effects on student learning. The first level of analysis explored the context of the curriculum and associated knowledge practices, and examined the pedagogic discourse evident in the curriculum. The second level of analysis revealed the inner logic structuring the curriculum and the associated knowledge practices. I used Maton’s Legitimation Code Theory (LCT): Specialisation to identify the specialisation codes, gazes and insights generated by the curriculum. For the third level of analysis, LCT: Semantics was used to generate the semantic profiles of learning activities to determine the extent to which the curriculum structure made cumulative learning possible. From the findings, it is evident that the verticality of knowledge in General Chemistry points to a recontextualising principle that prescribes the selection and arrangement of knowledge, and the special relationship of actors and discourses. As a result, the strong framing of the instructional discourse of General Chemistry curriculum structure is likely to constrain epistemological access for large numbers of students. In order to improve epistemological access to the field, weaker framing of the instructional discourse in introductory science is necessary. Weaker framing of the General Chemistry curriculum would require, in particular, changes to pacing, and that the evaluative criteria are made explicit. This is especially necessary when certain abstract and complex curricular content is taught, especially in the first semester. The findings also indicate that the nature of the organising principles in the curriculum are significant for improving epistemological access to knowledge. In terms of LCT: Specialisation, the General Chemistry curriculum generated a knowledge code and downplayed differences among social categories of students, thus positioning all equally in relation to the knowledge and practices of the field. Therefore, the structuring of the curriculum emphasises and legitimates students who have attained specialist knowledge without considering the nature of the new student coming into the educational setting. Simply, what is privileged is both the object of study (theoretical knowledge) and how it is studied (procedural knowledge). This finding is in line with the general outcomes of Chemistry education. In addition, the purist insight generated by the curriculum further attests to where the emphasis is placed in the curriculum. I argue that the lack of social relations in the curriculum poses a challenge for the holistic development of students as science knowers. The analysis of the learning activities shows rapid code shifts that indicate changes in cognitive demand and modes of thinking required of students. I argue that signposting the changes in complexity of knowledge and in the mode of thinking required could make learning, and thus epistemological access, more possible. Given the imperative of access to powerful knowledge, I contend that the curriculum should be reshaped to enable epistemological access for more students.
Full Text:
Date Issued: 2018

Quick View

Modernisation and extension of InetVis: a network security data visualisation tool

- Johnson, Yestin

Authors: Johnson, Yestin
Date: 2019
Subjects: Data visualization , InetVis (Application software)
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/69223 , vital:29447
Description: This research undertook an investigation in digital archaeology, modernisation, and revitalisation of the InetVis software application, developed at Rhodes University in 2007. InetVis allows users to visualise network traffic in an interactive 3D scatter plot. This software is based on the idea of the Spinning Cube of Potential Doom, introduced by Stephen Lau. The original InetVis research project aimed to extend this concept and implementation, specifically for use in analysing network telescope traffic. The InetVis source code was examined and ported to run on modern operating systems. The porting process involved updating the UI framework, Qt, from version 3 to 5, as well as adding support for 64-bit compilation. This research extended its usefulness with the implementation of new, high-value, features and improvements. The most notable new features include the addition of a general settings framework, improved screenshot generation, automated visualisation modes, new keyboard shortcuts, and support for building and running InetVis on macOS. Additional features and improvements were identified for future work. These consist of support for a plug-in architecture and an extended heads-up display. A user survey was then conducted, determining that respondents found InetVis to be easy to use and useful. The user survey also allowed the identification of new and proposed features that the respondents found to be most useful. At this point, no other tool offers the simplicity and user-friendliness of InetVis when it comes to the analysis of network packet captures, especially those from network telescopes.
Full Text:
Date Issued: 2019

Quick View

Transformative ICT education practices in rural secondary schools for developmental needs and realities: the Eastern Cape Province, South Africa

- Simuja, Clement

Authors: Simuja, Clement
Date: 2020
Subjects: Education, Secondary -- South Africa -- Data processing , Information technology -- Study and teaching (Secondary) --South Africa , Educational technology -- Developing countries , Rural development -- Developing countries , Computer-assisted instruction -- South Africa -- Eastern Cape , Internet in education -- South Africa , Rural schools -- South Africa -- Eastern Cape , Community and school -- South Africa -- Eastern Cape
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/150631 , vital:38991
Description: The perceived social development significance of Information and Communication Technology (ICT) has dramatically expanded the domains in which this cluster of ICTs is being discussed and acted upon. The action to promote community development in rural areas in South Africa has made its way into the introduction of ICT education in secondary schools. Since rural secondary schools form part of the framework for rural communities, they are being challenged to provide ICT education that makes a difference in learners’ lives. This requires engaging education practices that inspire learners to construct knowledge of ICT that does not only respond to examination purposes but rather, to the needs and development aspirations of the community. This research examines the experience of engaging learners and communities in socially informed ICT education in rural secondary schools. Specifically, it seeks to develop a critique of current practices involved in ICT education in rural secondary schools, and explores plausible alternatives to such practices that would make ICT education more transformative and structured towards the developmental concerns of communities. The main empirical focus for the research was five rural secondary schools in the Eastern Cape Province in South Africa. The research involved 53 participants that participated in a socially informed ICT training process. The training was designed to inspire participants to share their self-defined ICT education and ICT knowledge experiences. Critical Action Learning and Philosophical Inquiry provided the methodological framework, whilst the theoretical framework draws on Foucault’s philosophical ideas on power-knowledge relations. Through this theoretical analysis, the research examines the dynamic interplay of practices in ICT education with the values, ideals, and knowledge that form the core-life experiences of learners and rural communities. The research findings of this study indicate that current ICT education practices in rural secondary schools are endowed with ideologies that are affecting learners’ identity, social experiences, power, and ownership of the reflective meaning of using ICTs in community development. The contribution of this thesis lies in demonstrating ways that reframe ICT education transformatively, and more specifically its practices in the light of the way power, identity, ownership and social experience construct and offer learners a transformative view of self and the world. This could enable ICT education to fulfil the potential of contributing to social development in rural communities. The thesis culminates by presenting a theoretical framework that articulates the structural and authoritative components of ICT education practices – these relate to learners’ conscious understandings and represented thoughts, sensations and meanings embedded in the context, and actions and locations of using their knowledge of ICT.
Full Text:
Date Issued: 2020

Quick View

Baseline description of the Benthic Biotopes for two Long-Term Ecological Research (LTER) stations in Algoa Bay, Agulhas ecoregion, South Africa

- Parker-Nance, Shirley

Authors: Parker-Nance, Shirley
Date: 2021-10-29
Subjects: Benthic ecology South Africa Algoa Bay , Long-Term Ecological Research Program , Marine invertebrates South Africa Algoa Bay , Reef ecology South Africa Algoa Bay , Coastal zone management South Africa Algoa Bay , Reef fishes South Africa Algoa Bay , Ecological mapping South Africa Algoa Bay
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10962/191680 , vital:45147 , 10.21504/10962/191680
Description: Shallow coastal marine ecosystems provide important resources to society but are increasingly under threat from anthropogenic impacts. These systems form an interface between land and sea, providing valuable resources. Global environmental change, overexploitation, habitat transformation, pollution and policies aimed at short-term socio-economic gains are driving the loss of natural resources, productivity and biodiversity. Consequently, a comprehensive and holistic understanding of the current and future states of marine ecosystems is essential. This requires insight into the processes involved in maintaining genetic, species, habitat, community and biotope diversity at an ecosystem level. An understanding of ecosystem processes and the ability to detect changes in biodiversity, biotopes, seascape composition and ecosystem functioning require observation made over time and space. In response to this need, Long-Term Ecological Research (LTER) programmes such as those established by the South African Environmental Observation Network (SAEON) supported by the Department of Science and Innovation’s (DSI) Shallow Marine and Coastal Research Infrastructure (SMCRI) collect long–term observational data from different environments and systems. This study aimed to evaluate data collected as part of the developmental phase of a newly established benthic research platform. The datasets constructed are used to develop a baseline description of the benthic biotopes of two study areas within Algoa Bay. It aimed to gain insight into the feasibility of the methods used and the value of the data and derived essential biological variables (EVB). Assessing the sustainability of the programme over time was done through a practical evaluation of the methodology to be used and the technical feasibility of data collection and analysis. It furthermore aimed to assess the data usefulness in describing biodiversity at various scales and its sensitivity in reporting change. This pilot study provides valuable insight into data collection methodologies and introduces new sampling platforms. The baseline dataset consisted of data collected during the first 18 months of the SAEON Benthic Ecosystem Long-Term Ecological Research (BELTER) platform in Algoa Bay, Agulhas ecoregion, Western Indian Ocean, South Africa. This comprised of the collection of images for 150 m2 of the researched benthic seascape and 306 stereo video data streams. The 77 760 point dataset allowed the identification of 12 substrate types, 7 biotopes, 44 sub-biotope units, 377 sessile and sedentary benthic species and 51 ichthyofauna species. The described habitat and benthic communities and the defined benthic biotopes allowed for the assessment of biotope heterogeneity and the construction of a provisional distribution map for the broader biotopes. This work includes a study into the infra- and supra-benthic ichthyofauna associated with the defined biotopes and investigates the role habitat and benthic communities play in the distribution of these fish 3 assemblages. Lastly, it assesses the value of morphological traits and diversity indices for describing and comparing abiotic and biotic components of observed systems within the shallow coastal marine seascape. This study shows that species composition differs significantly between biotopes with habitat type playing a key role in the composition of the benthos. Substrate type, consolidated or unconsolidated, depth and the composition of the soft sediment is the most important determining factors. The White Sands Reef station has a higher species diversity than the St Croix Island Complex station with a higher percentage cover associated with the hard substrate. The dissimilarity between biotopes and communities are generally high although similarity within the biotopes or communities was found to be relatively low. This was considered indicative of high heterogeneity within the biotopes and a patch or mosaic-like distribution of communities within the broader biotope. A fine-scale a posteriori analysis of the data collected confirmed the high heterogeneous nature of both habitat and communities within the broader biotope. The description of the abiotic and biotic variables resulted in the identification of a diverse suite of biotope subunits. The character of the biotope hinges not only on the composition of the substrate and biota present but the contribution of smaller distinct biotopes subunits, their distribution and representation within broader biotopes and the degree these are shared with other broader biotopes. The distribution of these biotope units at different scales is believed to be important in understanding inherent diversity, niche partitioning and connectivity within a highly heterogeneous seascape. Ichthyofauna associated with the broader biotopes were indicative of the substrate type. Low profile reef systems with interspaced sandy stretches supported both reef fish and those typically associated with sandy substrates. Benthic biotopes associated characteristically with higher profile reef systems and less sand or soft sediment were mainly utilized by reef-associated fish species. Substrate type, depth and seasonality were found to be important factors in the observed composition and distribution of ichthyofauna over the seascape. Although fish species were found to have a wide distribution and made use of multiple biotopes the average abundance of the species within the observed assemblages differed. Analysis of ichthyofauna species composition indicated that observed fish assemblages were homogeneous within five of the seven biotopes. Broader biotopes that were found to be significantly different between sample locations are characterised by a diverse complement of biotope subunits and are highly heterogeneous. Traits and diversity indices are important tools for assessing and comparing different systems within the seascape, both spatially and temporally. The classification of the biota into broader phylogenetic groups indicated a significant difference between biotopes. This is especially useful when detailed 4 analysis or species identification is not possible or the skill set is not available. Morphological traits included in this study informed on the physical structure of the communities present and in combination with substrate type provided insight into the three-dimensional structure of the biotope. Species diversity, abundance, density estimates and the Shannon-Weiner diversity index were found to be the most useful diversity indices characterising and comparing biotopes. This was less so for ichthyofauna. Significant differences in the number of species observed were evident only between consolidated and unconsolidated dominated substrates. Although there was no significant difference in the number of individuals observed, both the Shannon-Weiner and Simpson Diversity indices were able to highlight differences in the fish assemblages observed for the different biotopes. The data collected, although permitting a comprehensive baseline assessment of the benthic environment for two research stations within the SAEON Algoa Bay LTER Sentinel Site, is temporally limited. The ichthyofauna dataset used was small and it is understood that the addition of length-frequency analysis of observed ichthyofauna will benefit our understanding of the biotope use by infra- and supra-benthic fish species over their life history within the larger seascape. Seasonal differences were evident and it is expected that datasets spanning several years, including LTER stations within different marine ecosystems types, will provide valuable insights on system dynamics in the short and long term both spatially and temporally. This study is the first attempt to evaluate the methodology developed and data collected in the South African Environmental Observation Network’s, Elwandle Coastal Node as part of the Shallow Marine and Coastal Research Infrastructure Benthic Ecosystem Long-Term Ecological Research (BELTER) platform. Newly designed and developed sample equipment and a sampling regime allowed for the collection of data on a long-term basis. The study was successful in the description of the biotope and biotope subunits for two research stations in Algoa Bay. It permitted the construction of comprehensive species lists for both benthic sessile and sedentary biota and the associated ichthyofauna. The subset of data used was successful in reporting on both spatial and temporal change. This work demonstrates that in the absence of detailed species identifications, traits may be used to describe habitat and community structure and report on abiotic and biotic biotope characteristics. This study furthermore allowed for the comparison of a comprehensive suite of diversity indices highlighting indices that may be especially useful in routine BELTER reporting. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
Full Text:
Date Issued: 2021-10-29

Quick View

Design of Immunobiosensors for Detection of Tumor-Associated Anti-P53 Autoantibodies: Method Development

- Adeniyi, Omotayo Kayode

Authors: Adeniyi, Omotayo Kayode
Date: 2020
Subjects: Uncatalogued
Language: English
Type: thesis , text , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/162988 , vital:41002 , 10.21504/10962/162988
Description: Introduction -- Experimental -- Label-Free Impedimetric Sensing of Anti-P53ab... -- Fluorescent detection of Anti-P53ab -- Peroxidase-like activity of Fe3O4@SiNP-APTES-Au@Pd... -- Colorimetric detection of Anti-P53ab , Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020. , Detection and profiling of circulating tumor-associated autoantibodies (TAAbs) are useful for screening and early-stage diagnosis of asymptomatic lung cancer. Immunobiosensor technologies aimed to accomplish the highly sensitive, rapid and low-cost detection of TAAbs can improve the early-stage detection of lung cancer. Immunobiosensors for the detection of anti-P53-tumour associated autoantibodies have been developed in this work. The design of sensing interfaces with immobilized P53 protein (P53ag) as a sensing element layer on a solid interface was investigated. Several methods of detecting anti-P53-antibodies (anti-P53ab) were investigated. These methods are label-free detection using electrochemical impedance spectroscopy (EIS) and two label techniques. The label-free electrochemical techniques utilize gold electrode pre-modified with a conducting layer of electrochemically grafted phenylethylamine for covalent immobilization of P53ag. The limit of anti-P53ab detection with the label-free EIS was 103.0 pg.ml-1. The labeled technique developed utilizes fluorescent, and peroxidase-like nanomaterial labeled antibody as a detection probe. For the fluorescence detection, fluorescent silica nanoparticles were synthesized by overloading FITC into the silica matrix and conjugated to detection antibody (anti-IgG). The detection of the anti-P53ab was based on the dissolution of the silica nanoparticles to release the loaded dye as a signal amplification strategy. The fluorescence detection was carried out on a microplate, and magnetic bead modified P53-antigen platforms and limit of detection (LoD) were 42.0 fg.ml-1 and 3.3 fg.ml-1 for anti-P53ab; respectively. Fe3O4@SiNP-APTES-Au@Pd hybrid nanoparticles were synthesized, and their peroxidase-like activity and colorimetric detection were evaluated. The Fe3O4@SiNP-APTES-Au@Pd exhibited comparable activity to HRP. The Fe3O4@SiNP-APTES-Au@Pd was conjugated to protein-G-anti-IgG for the detection of anti-P53ab on a microplate and cellulose paper platforms. The LoD was 20.0 fg.ml-1 and 63.0 fg.ml-1 for the microplate and cellulose paper platform; respectively. The potential application of the designed immunobiosensor was evaluated in simulated serum samples. The developed sensors showed higher detection sensitivity, stability and had a lower detection limit for anti-P53ab when compared with the ELISA based detection. The results have provided alternative and effective quantification approaches to ELISA and a promising future for multiplexed detection of tumor-associated autoantibodies. The developed methodologies in this thesis could be applied for the detection of other autoantibodies in other cancer types and auto-immune diseases.
Full Text:
Date Issued: 2020

Quick View

Zimbabwean women online: an investigation of how gendered identities are negotiated in Zimbabwean women’s online spaces

- Ndlovu, Nonhlanhla

Authors: Ndlovu, Nonhlanhla
Date: 2020
Subjects: Woman -- Zimbabwe -- Social life and customs Social media -- Social aspects -- Zimbabwe Facebook (Firm) Women -- Zimbabwe
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/140452 , vital:37890
Description: This study is concerned with the construction of Zimbabwean women’s identities in this contemporary internet age. Two Facebook groups are of particular interest here due to the vibrant conversations that take place on a daily basis, that is, Makhox Women’s League and Baking & Cooking: ZW Women’s Diaries. Conceiving these internet sites as discursive spaces, I unpack the contesting discourses and tensions in the different narratives offered by Zimbabwean women and identify and critique the competing sets of feminine subjectivities. I achieve this by drawing on poststructuralist and postcolonialist feminist theories in order to situate these groups as cultural sites that are particularly identity defining. I particularly draw on Foucauldian theories of discourse, power and the subject to conceptualise the formation of particular discursive gendered subjectivities. With an understanding that discourse is constitutive of power relations and contestations, and that discourse should be historically contextualised in order to take into account particular conditions of existence; I draw on Mamdani’s (1996) conceptualisation of how power is organised in Africa within a historical and institutional context, and identify the bifurcated nature of the postcolonial Zimbabwean state as a colonial residue as necessitating a particular kind of subjectivity. To this end, one can understand the different femininities on Makhox Women’s League and Baking & Cooking: ZW Women’s Diaries as constituted within, and complexly negotiating, a traditional/customary discourse and a rights-based modern one. This qualitative inquiry is informed by an eclectic approach that combines methods of textual analysis that complements both critical linguistics and media studies and attends to lexical structure as well as narrative and rhetorical analysis respectively. Combined with an online ethnographic approach I employ these tools to analyse these particular Facebook groups with the understanding that as women converse daily on these platforms, they ‘govern’ each other’s conduct and thought processes in interesting ways. I argue that these conversations discursively constitute the performances of different femininities on both sites that also take into account the diasporic condition of Zimbabwean women. I show how they negotiate and mediate feminine performance and in so doing propose and contest certain ‘truths’ that are frequently validated.
Full Text:
Date Issued: 2020

Quick View

Showing items 1 - 20 of 1898