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Retrospective analysis of factors contributing to parasuicide among youth in Buffalo City Metropolitan Municipality, Eastern Cape, South Africa

  • Authors: Nganto, Yanga
  • Date: 2021-11
  • Subjects: Parasuicide -- South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/22897 , vital:53181
  • Description: Parasuicide is a problem that affects the youth locally and globally. Parasuicide has negative psychological impacts on youth. This study was designed to assess elements of parasuicide in the Buffalo City Metropolitan Municipality of South Africa, using records of patients admitted to Frere and Cecilia Makiwane hospitals between 2016 and 2020. The purpose of the study was to conduct a descriptive retrospective review of parasuicide among youth to determine trends, causes, and contributing factors of committing parasuicide. Methods A retrospective, quantitative and descriptive study was conducted with 200 files of patients aged between 18 and 35 years conveniently sampled. These patients diagnosed as committed parasuicide and were admitted at Frere and Cecilia Makiwane hospitals over a period of four years from 1 April 2016 to 31 March 202. Only record files of patients’ residing in East London and Mdantsane catchment area were selected. Raw data was collected for a period of twelve weeks using a developed data collection tool developed in Ms Excel spreadsheet. Results In this sample, the large number of the patients were under 26 years (60.5%), female (57%), single (92.5%), and Black (99.5%). Furthermore, majority of the patients had attained secondary education (89.5%), were unemployed (83%) and living with their families (59%). There were different methods and agents used by participants to commit parasuicide and reasons differed from person to person. Among patients who reported a suicide attempt, organophosphates were most commonly used agent for self-poisoning (47%, n=94), followed by substances such as use of drugs and alcohol (n=57, 28.5%), violence (n=27, 13.5%), corrosive agents including bleach and Jik (n=11, 5.5%), and hydrogen peroxide including acidic sub-stances like battery acid (n=11, 5.5%). The common reason found in the study and indicates participants had psychiatric disorder (34.5%). Conclusion Limiting access to organophosphate agents and other lethal means is an effective strategy that should be adopted to prevent parasuicide among youth. Timely identification of risks or warning signs, social prevention and immediate intervention at the state level will play an important role in controlling parasuicide among youth. Moreover, improving health care services with psychotherapy support would empower youth with skills that would enhance their self-confidence, self-worth and resilience. Consequently, attainment of these attributes would result in the prevention and control of parasuicide amongst youth. , Thesis (MPH) -- Faculty of Health Sciences, 2021
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  • Date Issued: 2021-11

Neutral Atomic Hydrogen in Gravitationally Lensed Systems

  • Authors: Blecher, Tariq Dylan
  • Date: 2021-10-29
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/192776 , vital:45263
  • Description: Thesis (PhD) -- Faculty of Law, Law, 2021
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  • Date Issued: 2021-10-29

Ecosystem-scale impacts of non-timber forest product harvesting: Effects on soil nutrients

  • Authors: Ruwanza, Sheunesu , Shackleton, Charlie M
  • Date: 2017
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/180099 , vital:43309 , xlink:href="https://doi.org/10.1111/1365-2664.12891"
  • Description: The harvesting of non-timber forest products (NTFPs) is a global phenomenon, the sustainability of which has been studied for many species at the individual and population level. However, the broader scale impacts of NTFP harvesting have been acknowledged but rarely examined. We assessed plant size and the soil attributes undercanopy and in the open, in replicate, paired harvested and non-harvested sites for three NTFPs differing in the extent of biomass removed, i.e. timber for firewood from a tree (Acacia karroo), fruits from a cactus (Opunita ficus-indica) and flowering culms from a grass (Cymbopogon marginatus). Soil variables tested included pH, resistivity, P, total N, nitrate nitrogen, ammonium nitrogen, K, Na, Ca and Mg. The extent of loss of soil nutrients decreased across the three NTFPs relative to the proportion of biomass removed. Thus, significant differences in more soil variables were evident for the firewood species, least for the fruit species and intermediate for the grass species. Lower soil pH, P, C and K were evident in soils collected underneath A. karroo, while losses in cations of Na, Ca and Mg were reported in soils underneath C. marginatus, and only NO3N losses were recorded underneath O. ficus-indica. Our study reveals that while non-timber forest product (NTFP) harvesting may affect soil nutrients, this is not uniform between species and is likely to be a function of the extent of biomass removed and harvesting frequency. This indicates the need for caution in generalisations about the ecosystem-level impacts of NTFP harvesting as well as a concerted effort to better understand impacts at a greater range of scales than has been the case to date.
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  • Date Issued: 2017

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

  • 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
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  • Date Issued: 2022-04-07

Using information visualization to support the self-management of type 2 diabetes mellitus

  • Authors: Nauder, Meggan Kate
  • Date: 2022-04
  • Subjects: Information visualization , Diabetics --Treatment --South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/55711 , vital:53409
  • Description: The globally increasing number of individuals suffering from Type 2 Diabetes Mellitus (T2DM), a completely preventable incurable disease of the pancreas, highlights the need for an effective tool for users to understand the relationship between their behaviours and the effect that those behaviours can have on their blood glucose levels (BGLs). There are few Information Visualisation (IV) tools available that can be used to reduce the cognition required to understand correlations between behaviour and BGLs. Existing tools require time-consuming, lengthy inputs and provide simple visualisations that do not show correlations. This leads to ineffective self-management of T2DM. Information Visualisation (IV) techniques can be used to support effective self-management of T2DM and reduce the cognition required to interpret DM data. Suitable IV techniques were identified and used to visualize T2DM data to aid in the self-management of the disease. Temporal charts, i.e. The Bar, Pie and Line Chart as well as heat maps, were selected as the most appropriate IV techniques to visualize T2DM data as they support time-series data well. A prototype, MedicMetric was created as an IV tool for visualizing T2DM data. MedicMetric incorporated three designed charts, namely the Change Rate Line View, the Radial Progress View, and the Annotated Line View. The Change Rate Line View and Annotated Line View both used line IV techniques, while the Radial Progress View made use of the bar IV technique. The Change Rate Line View performed the worst overall. A usability evaluation was conducted to compare these techniques and to determine which technique is most suitable for visualizing T2DM data. The results leaned significantly in favour of the Annotated Line View. This view is most similar to the line charts typically used in other IV tools. For this reason, the MedicMetric app was briefly compared to the MySygr and Diabetes:M application. In effectiveness and efficiency, MedicMetric and MySugr obtained almost identical results. However, participants indicated that MedicMetric supported their tasks using the Visual Information Seeking Mantra (VISM) the best overall, with 100% of participants stating that they would prefer to use the MedicMetric application. Several usability problems were identified with the IV techniques and they were addressed shortly after the study was complete. Overall participants were most satisfied with the Annotated Line View. , Thesis (MSc) -- Faculty of Science, Computing Sciences, 2022
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  • Date Issued: 2022-04

Aptamer versus antibody as probes for the impedimetric biosensor for human epidermal growth factor receptor

  • Authors: Centane, Sixolile , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229884 , vital:49720 , xlink:href="https://doi.org/10.1016/j.jinorgbio.2022.111764"
  • Description: In the present work, the performance of aptamer and antibody bioreceptors for the detection of the human epidermal growth factor receptor (HER2) cancer biomarker on a glassy carbon electrode is reported. The carboxylic acid group rich graphene quantum dots (GQDs) modified with gold nanoparticles and a porphyrin binuclear framework (CoP-BNF) were used to modify the glassy carbon electrode. The aptamer and antibody were both amine functionalized and attached to GQDs and CoP-BNF through an amide bond. The designed immunosensors and aptasensors in this work were characterized using electrochemical impedance spectroscopy. The aptasensors, compared to the immunosensors gave better limit of detection values. The aptasensor outperforms the immunosensor in terms of its reusability and storability, while the immunosensor could not be regenerated for subsequent experiments. The potential applicability of all sensors in this work was also investigated, by detection of HER2 in spiked human serum with acceptable results.
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  • Date Issued: 2022

Stable Covalent pH-Sensitive Metallophthalocyanines Thin Monolayer Films for Selective Detection of Neurotransmitters

  • Authors: Idowu, Abosede Omowumi Atinuke
  • Date: 2021-10-29
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/192922 , vital:45279
  • Description: Thesis (PhD) -- Faculty of Humanities, Science, Chemistry, 2021
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  • Date Issued: 2021-10-29

Exploring the Teaching and Learning of Euclidean Geometry in Senior Secondary Schools: The Case of O R Tambo Coastal Schools

  • Authors: Danso, Agyare
  • Date: 2020-12
  • Subjects: Euclidean Geometry
  • Language: English
  • Type: Master's/Doctoral theses , text
  • Identifier: http://hdl.handle.net/11260/6582 , vital:47145
  • Description: This study was aimed at exploring the teaching and learning of Euclidean Geometry in five selected senior secondary schools in the O R Tambo Coastal District of the Eastern Cape, South Africa. The literature review was based on existing knowledge in the teaching and learning of Euclidean geometry. The study was built on analyzing the effective teaching strategies based on the teacher’s Pedagogical Content Knowledge (PCK) in Euclidean Geometry (EG). Shulman and Ma’s perspective on teachers’ competencies and knowledge of Mathematics was used as the theoretical framework of the study. A mixed-methods sequential explanatory design was adopted for the study. A purposive convenience sampling technique was used to select research sites and participants. The main instruments used were questionnaires, semi-structured interviews, classroom observation schedules, and document analysis. Quantitative data was analyzed descriptively utilizing tables and graphs. Qualitative data were analyzed using thematic data analysis. The various findings were interpreted through the literature and the theoretical framework. It was found that learners have a poor foundation in geometry and the methods teachers employed to teach Euclidean Geometry were inappropriate. Recommendations and suggestions were made. It is hoped that these recommendations would be noted by the appropriate stakeholders to ensure that improvement in the teaching and learning of Euclidean Geometry is achieved in our secondary schools to help matriculates’ obtain good marks in the final certification examination. Keywords: Euclidean Geometry, geometry teaching and learning; learners’ attitude; Teachers Pedagogical Content Knowledge , Thesis (M.Ed) -- Faculty of Education Sciences, 2020
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  • Date Issued: 2020-12

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

  • 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
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  • Date Issued: 2021-10-29

An Investigative Study of Parental Involvement in The Governance of Public and Private Schools in The Matatiele District of the Eastern Cape Province of South Africa

  • Authors: Mnukwa, Zolile Maxwell
  • Date: 2011
  • Language: English
  • Type: Masters theses , text
  • Identifier: http://hdl.handle.net/11260/3506 , vital:43617
  • Description: This is a comparative study of parental involvement in the governance of public and private schools in the Matatiele District of the Eastern Cape Province of South Africa. Parental involvement can range from occasional attendance of the school functions to partnership through parent teacher organizations and parent management bodies. Education is a national enterprise that requires the co-operation and participation of all the role players who are parents, community, teachers, learners and the Department of Education. The problem to be investigated in this study is: Why is it that parental involvement is more positive in the governance of private schools than that of public schools? Two schools were selected for the study and the researcher administered questionnaires personally by hand and conducted face to face interviews to collect the primary data. The responses of the administered questionnaire were tabulated and recorded in table form so as to give an accurate interpretation of what was revealed in the data. Patterns in the data were considered in order to provide an accurate interpretation of the information. The findings were divided into two, that is: findings from the public school and those from private schools. From the public school it was found that: parents are not involved in the governance of the school; the school does not involve parents on financial matters; parents do not attend meetings when invited; they do not know their roles and responsibilities, for example, according to the South African Schools Act (SASA), parents must be actively involved in the governance of the school in their community and that there is an element of ignorance and negligence on the part of parents towards their children’s education. From the private schools it was found that: parents are more involved in the governance of the school; they attend and participate actively in school meetings; the school involves parents in financial matters and as such the financial support from the parents is very good; parents are much involved in the monitoring of the progress of their learner’s education and are passionate about the school and seem to own the policies and the governance of the whole school system. The conclusion drawn from the study is that private schools allow for parental involvement in the governance of their schools whereas in public schools parental involvement is low. , Thesis (MMED) -- Faculty of Educational Sciences, 2011
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  • Date Issued: 2011

Assessing the electrocatalytic activity of a localized push-pull system in cobalt phthalocyanine/graphene quantum dot hybrids

  • Authors: Nkhahle, Reitumetse , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229909 , vital:49722 , xlink:href="https://doi.org/10.1016/j.matchemphys.2022.125842"
  • Description: In this study, two cobalt phthalocyanines (asymmetric complex 1) and symmetric (complex 2) were synthesized and conjugated to nitrogen-doped graphene quantum dots (NGQDs) through covalent and non-covalent means to create Co phthalocyanine (CoPc)-NGQDs hybrid systems. The CoPcs and conjugates were applied as electrode modifiers on a glassy carbon electrode in the electrochemical sensing of nitrite. Of the CoPcs alone, complex 1 performed better than complex 2 regarding the limits of detection (LoD) recorded (5.74 μM for 1 and 15.1 μM for 2). Regarding the conjugates/nanocomposites, the π-π stacked conjugate derived from complex 2 (2πNGQDs) demonstrated highly favourable electrochemical potential with an LoD value of 0.70 μM. The nanocomposites fashioned from complex 1 were marred by a reduced loading which rendered the conjugates poor electrochemical sensors. These observations however do not disqualify GQDs as complementary nanomaterials to phthalocyanines but rather shed light on seeking alternative routes to increasing the Pc loading in conjugates (more so in π-π stacked conjugates).
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  • Date Issued: 2022

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

  • 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
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  • Date Issued: 2021-04

Abundance and correlates of the Acacia dealbata invasion in the northern Eastern Cape, South Africa

  • Authors: Gouws, Aidan J , Shackleton, Charlie M
  • Date: 2019
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/179735 , vital:43165 , xlink:href="https://doi.org/10.1016/j.foreco.2018.09.048"
  • Description: An increase in the density and biomass of woody invasive plants contributes to the intensification of ecological impacts and can often be met with dissatisfaction by local communities. Despite their reliance on Acacia dealbata as a source of livelihood, villagers in the northern Eastern Cape have expressed concerns about the high densities of the species. This study sought to quantify the current abundance and growth of A. dealbata in selected landscapes in the northern Eastern Cape, around nine villages in rural Matatiele, Mount Fletcher and Maclear. Standard vegetation survey techniques were adopted to quantify the density, biomass and growth rate of A. dealbata. Overall, the average density, biomass and productivity of A. dealbata were estimated at approximately 7000 stems ha−1, 12 Mg ha−1 and 4 Mg ha−1 year−1, respectively. However, the abundance and productivity of A. dealbata were spatially variable between study areas. Acacia dealbata stems experienced significant growth over the period of a single year, contributing to substantial biomass production at the landscape level, despite continued harvest. Furthermore, relatively few biophysical variables were significantly influential correlates with the abundance of A. dealbata. Indeed, the degree of biological invasion can be highly variable across the landscape, shaped by the interaction of local-scale biophysical conditions.
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  • Date Issued: 2019

Refining predator-prey preference at the prey demographic level for cheetah and lion

  • Authors: Annear, Eleesha
  • Date: 2022-04
  • Subjects: Social behavior in animals --South Africa , Predatory animals –Behavior
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/55800 , vital:53880
  • Description: Traditional prey preference models estimate prey preference using a coarse species-specific body mass of three-quarters of the mean adult female body mass. This is widely assumed to estimate the average mass across prey populations, accounting for neonates, juveniles, sub-adults, and adults. However, this approach negates the models’ ability to predict demography-specific prey preferences, thus reducing our ability to predict the impacts of predation on prey populations. The objectives of this study were to 1) refine the prey selection models, using lion Panthera leo and cheetah Acinonyx jubatus as model species, by incorporating prey demographic classes and season and, 2) determine the influence of seasonal variability in availability of these prey demographic classes on cheetah reproduction. Lions preferentially killed adults of larger species (e.g., wildebeest, waterbuck, and zebra) irrespective of the season, as predicted by optimal foraging theory. Sub-adult, juvenile, and neonate prey were killed by lions relative to their abundance. Cheetahs preferred juvenile prey of large species, namely kudu, zebra, and wildebeest. Season influenced cheetah preference with neonates and juveniles being preferred during the wet season and adults of smaller species, and juveniles of larger species being preferred during the dry season. Thus, results support the alternative demographic class hypothesis. Furthermore, the availability of neonate and juvenile prey drives cheetah reproduction patterns with conception and cub independence coinciding with the peak availability of easy-to-catch neonates. Lactation coincided with the high availability of relatively larger juveniles to ensure that females obtain enough resources to sustain the most energetically costly reproductive phase. In addition, I suggest cheetah may be particularly vulnerable to disturbances that impact on prey reproduction (e.g., drought, fire, and flood), given their reliance on neonate and juvenile prey. My findings highlight that estimating species-level prey preference using a coarse species-specific body mass masks the level of prey use and potential preferences for the different prey demographic classes. The use of some prey species may be largely confined to juveniles by smaller predators, meaning that prey availability would vary seasonally, may influence reproductive patterns, and carrying capacity models would need to be revised in terms of the available demographic-specific prey biomass. , Thesis (MSc) -- Faculty of Sciences, School of Environmental Sciences, 2022
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  • Date Issued: 2022-04

Comparative analysis of the known Hop1b and the novel Hop1a isoforms of the Hop gene

  • Authors: Makhubu, Portia
  • Date: 2020
  • Subjects: Uncatalogued
  • Language: English
  • Type: thesis , text , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/164311 , vital:41108 , doi:10.21504/10962/164311
  • Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
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  • Date Issued: 2020

Green Synthesis of HIV-1 Protease Inhibitors

  • Authors: Hartley, Shaun Neil
  • Date: 2021-10
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/190145 , vital:44967
  • Description: Thesis embargoed until October 2022 , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
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  • Date Issued: 2021-10

Behavioural activities and chemical composition of fresh leaf essential oil of Plectranthus aegyptiacus from Southwest Nigeria in mice

  • Date: 2021-6
  • Subjects: Acute toxicity testing Carvacrol Essential oil Behaviour Modification Plectranthus Article
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/6506 , vital:46434 , ("https://doi.org/10.30574/gscbps.2021.14.2.0030")
  • Description: Objectives: This study determined the chemical composition of essential oil obtained from fresh leaf of Plectranthus aegyptiacus, and evaluated it for novelty-induced behavioural (NIB) and determine its mechanism(s) of action in mice. Methods: The oil was hydro-distillated, and analyzed using gas chromatography-mass spectrometry. The effects of the oil (50, 100 and 150 mg/kg; i.p., n=6) on novelty-induced behavioural was assessed using open field test and head dipping on hole board. Probable mechanism(s) were evaluated using antagonists: flumazenil, naloxone and cyproheptadine at 2 mg/kg each, atropine and yohimbine at 5 mg/kg and 1 mg/kg respectively. Key Findings: The LD50 values obtained were 2154 and 490 mg/kg for oral and intraperitoneal routes respectively. The oil (50, 100 and150 mg/kg) significantly (p less 0.05, 0.01 and 0.01) inhibited all NIB and head dips. Flumazenil significantly (p less than 0.05) reversed the effect of the oil on NIB; atropine, naloxone and cyproheptadine significantly (p less than 0.01, 0.01 and 0.001) potentiated inhibitory effect on NIB respectively, while yohimbine showed no significantly effect. The analyzed oil showed 61 compounds, and the major compounds were carvacrol, germacrene-D, p-cymene and [1,1'-Bicyclopentyl]-2,2'-diol. Conclusions: The study concluded that the oil possessed central nervous system depressant activity, which could be mediated mainly through augmentation of GABAergic neurotransmission, while cholinergic-(muscarinic), adrenergic and serotonergic pathways may be involved.
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  • Date Issued: 2021-6

Study South Africa

  • Authors: International Education Association of South Africa (IEASA) , Higher Education South Africa (Organization) , Kishun, Roshen
  • Date: 2007
  • Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/65090 , vital:28685 , ISBN 9780620391634
  • Description: [Extract from message from Minister of Higher Education, Hon. Naledi Pandor]: It gives me great pleasure to endorse the 7th edition of Study South Africa. The International Education Association of South Africa (IEASA) has once again produced a publication that provides valuable insights and information about South African public universities and their place in the global higher education arena I welcome this publication and congratulate IEASA for its hard work in promoting our higher education institutions internationally. Study South Africa gives a comprehensive picture of higher education in our country. At a glance, the enquirer is able to see all that South African higher education has to offer diversity in terms of institutions, the wide range of affordable courses on offer, the international acceptability of South African qualifications as well as the rich multi-cultural experiences of our campuses. In short, the Guide provides a summary of everything that will assist the potential student to actualise his or her full potential. South African higher education is founded on broad social values such as respect for human life and dignity, commitment to equality and human rights, respect for diversity and nonsexism. Our education system seeks to construct citizens who are conscious of these values and therefore aware of their responsibilities in life and in the lives of others. These values are reflected in the diverse offerings by institutions covered in the Guide. In addition, we have specific mechanisms in place to facilitate internationalisation, and our immigration policies have been relaxed to make it easier for international students, academics and other higher education staff to enter the country and stay for the duration of their planned activity. We also subsidise students from the continent in terms of our policy on the state subsidisation of foreign students at higher education institutions. South Africa shares the global concern about the digital and information divide. We are of the view that access to information is empowering and would therefore like to see as many citizens of our country and the continent connected with the rest of the world, both digitally and in terms of knowledge. By staying in touch with the rest of the world through information sharing and exchange programmes, we minimise this information gap. It is for this reason, therefore, that the work of IEASA in the form of this publication is applauded, because it seeks to promote such exchanges and information sharing. There is no question that through internationalisation we can impact on our political, economic, cultural and social transformation. We can also address our skills shortage, build research capacity, enrich curricula and enhance the student experience. Collectively higher education institutions in South Africa offer an impressive array of information and communication technologies, well stocked and interconnected libraries and some scholars who are among the best in the world, making the country a destination of choice for both Africans and students from abroad. We aspire to make all our international partners, students and staff feel at home and content with what our institutions offer them, pleasant living and study or work environments. We want them to be proud of their association with South African higher education and be ambassadors for the system once they leave South Africa. , 7th Edition
  • Full Text:
  • Date Issued: 2007

Synthesis and photophysicochemical properties of zinc phthalocyanine derivatized with benzothiazole or carbazole photosensitizers

  • Authors: Khoza, Phindile , Antunes, Edith M , Nyokong, Tebello
  • Date: 2013
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/241728 , vital:50964 , xlink:href="https://doi.org/10.1016/j.poly.2013.05.046"
  • Description: The synthesis of new zinc phthalocyanine complexes containing 3-(2-benzothiazol-2-yloxy) (complex 3) and 3-(carbazol-2-yloxy) (complex 4) substituents at the non-peripheral positions are reported. The new compounds were characterized by elemental analysis, FT-IR, 1H NMR, mass spectrometry and UV–Vis spectroscopy. The effects of carbazole and benzothiazole substitutents on the photophysical and photochemical parameters of ZnPc are reported. These new phthalocyanines are non-aggregated in common solvents and show improved photophysicochemical properties. The 3-(2-benzothiazol-2-yloxy) substituted complex showed the longest triplet lifetime ever reported for a zinc phthalocyanine (1.7 ms).
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  • Date Issued: 2013

Nanosecond nonlinear optical limiting properties of new trinuclear lanthanide phthalocyanines in solution and as thin films

  • Authors: Sekhosana, Kutloana E , Amuhaya, Edith , Nyokong, Tebello
  • Date: 2015
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/189752 , vital:44928 , xlink:href="https://doi.org/10.1016/j.poly.2014.08.047"
  • Description: 2,4,6-Tris[3-thio-9,10,16,17,23,24-hexa(4-tertbutylphenoxy) phthalocyaninato ytterbium (III) chloride]-s-triazin (3) and its lutetium counterpart (4) were synthesized. The nonlinear optical behavior of 3 and 4 were characterized in solution and when embedded in polymer as thin films. Thin films of complexes 3 and 4 in poly(bisphenol A carbonate) showed improved nonlinear optical properties when compared to solution. Complex 3 showed a lower threshold for optical limiting intensity (Ilim) than complex 4, and for phthalocyanines in general. Ilim values were even lower in films compared to solutions.
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  • Date Issued: 2015
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