An investigation into the knowledge a Grade one teacher uses to develop the number sense of learners with mathematics learning difficulties
- Authors: Fleming, Kirsty Ann
- Date: 2020
- Subjects: Learning disabled children -- Education -- South Africa , Mathematics -- Study and teching (Elementary) -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/141533 , vital:37983
- Description: Learners in South Africa continue to underperform in the international and national mathematics benchmarking tests. In the primary school, poor performance in mathematics is viewed as an indicator of limited number sense. Since the end of Apartheid, there has been a proliferation of classroom-based research that attempts to explain why learners are underperforming and find solutions to the problem. Research that seeks to explain learner underperformance attributes poor learner performance to social-economic issues, teachers’ poor content and pedagogical knowledge, the complexity of the Language of Learning and Teaching, and insufficient support for learners with Mathematics Learning Difficulties (MLD). With regards to the latter, research suggests that Foundation Phase teachers are not equipped to assist learners with MLD develop their number sense. This qualitative case study aims to investigate the knowledge that an expert Foundation Phase teacher draws on, in the process of teaching, to assist learners with MLD develop their number sense. Data generated from observations and interviews with a Grade One teacher was analysed using Rowland, Turner and Thwaites’ (2013) Knowledge Quartet. The study found that the participant Grade One teacher employed all four categories of the Knowledge Quartet when developing her learners’ number sense. In particular, she placed strong emphasis on vocabulary development as a means of circumnavigating MLD when developing number sense in a Grade One mathematics lesson. She demonstrated knowledge of: the importance of vocabulary in learning mathematics; how to develop the learners’ understanding of mathematics vocabulary (and concepts); and how to adapt her approach to support the number sense development of learners with MLD. This research has value for teacher education programmes, both pre- and in-service, as it highlights the knowledge that a Grade One teacher draws on as she develops the number sense of all her learners, including those with MLD.
- Full Text:
- Date Issued: 2020
Initiating biological control for Nymphaea mexicana zuccarini (Nymphaeaceae) in South Africa
- Authors: Reid, Megan Kim
- Date: 2020
- Subjects: Nymphaea mexicana zuccarini -- Biological control -- South Africa , Nymphaeaceae -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/144510 , vital:38352
- Description: Nymphaea mexicana Zuccarini (Nymphaeaceae) is an aquatic plant originating from south-eastern USA that is becoming increasingly invasive in South Africa as other invasive aquatic plants are being managed successfully through biological control. Mechanical and chemical control of aquatic weeds is expensive, damaging to the environment, and only effective in the short term, so biological control is more desirable as a management strategy for N. mexicana. The biological control of invasive alien plants requires that agents are host specific so that non-target risks are mitigated. For success to be achieved, it is important to ensure that the genetic structure of invasive populations is clarified so that agents can be collected from populations in the native range that match genetically to populations in the invasive range. This is especially important in cases where the morphology of invasive alien plants does not reflect genetic differences between populations. A previous study of the genetic structure of the invasive populations of N. mexicana in South Africa suggests the presence of hybrid forms of the plant in South Africa, with only one of these populations matching with samples from the native range. However, the study only used samples from two sites in the native range using amplified fragment length polymorphisms (AFLPs), so it was necessary to conduct further genetic analyses using samples from more sites in the native range. Hence, the first aim of this study was to develop a better understanding of the genetic structure of N. mexicana populations in the native and invaded range. Genetic samples were collected from sites in the native range during field surveys for potential biological control agents, and inter-simple sequence repeats (ISSRs) were used to compare the genetic structure of invasive and native populations of N. mexicana in South Africa. The results from these analyses suggest that seven of the 14 investigated invasive populations of N. mexicana in South Africa are genetically similar to populations in the native range, while the remaining seven populations are likely to be hybrid forms of the plant. This knowledge will be useful to target populations for biological control and highlights the need for further genetic analyses to determine the parentage of these hybrids so that biological control efforts are more likely to be successful. The initiation of a biological control programme requires that a series of steps are taken in order to maximise the likelihood that this form of intervention will be successful. The first few steps include: identification of the target weed and its genetic structure; exploration in the native range for potential biological control agents; and prioritisation of these agents based on factors such as climatic and genetic compatibility, feeding damage, abundance, and likely host range. Hence, the second aim of this study was to conduct surveys for potential biological control agents in the native range of N. mexicana, and to prioritise these agents. Field surveys were conducted between August and October in 2018 at 17 sites in Florida, Louisiana, and Texas, USA. Sites were selected based on climatic similarity of native sites compared to invasive sites by use of MaxEnt modelling. Native N. mexicana plants were searched for natural enemies, and these were prioritised based on feeding damage, abundance, incidence, and observations of field host range. Two species were prioritised: Bagous americanus LeConte (Coleoptera: Curculionidae) and Megamelus toddi Beamer (Hemiptera: Delphacidae). These species will be imported into quarantine facilities at Rhodes University for host specificity tests to be conducted. Understanding the factors that contribute to the successful establishment of biological control agents is important to improve the efficiency and reduce the costs incurred during the initiation of biological control programmes. Acquiring knowledge of the factors that predict the efficacy of biological control agents is similarly important, and these factors are discussed in the last chapter of this study. The challenges of the biological control of hybrids are also considered, and recommendations are made for the control of N. mexicana and other plants in South Africa.
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- Date Issued: 2020
Understanding of biological teleology from a naturalistic perspective
- Authors: Abrahams, Sanaa
- Date: 2020
- Subjects: Teleology , Biology -- Philosophy , Evolution (Biology) -- Philosophy
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140534 , vital:37896
- Description: To the extent that teleological thinking is metaphysically suspect, many theorists attempt to shift the stigma of functional explanations by reducing function ascriptions, and aim thus to de-legitimise an appeal to teleological causal relations in an analysis of function. The point is to dispel the mystery which envelops the application of function concepts by reformulating biological functional explanations so as to dispense with teleology. My project is to interrogate the success with which teleological explanations have thus been eliminated in the biological sciences, and, over the course of this thesis, I conclude that a kind of teleological causation nevertheless remains the most adequate explanatory ground of natural products. My proposal is that functional explanations are causal explanations for the presence and maintenance of self-reproducing systems. I contend that, insofar as the attribution of function presupposes the valuation of a function-bearing system as a causal necessity for its constituent parts, functional explanation references distinct and irreducible holistic properties. Using Kantian metaphysics to frame the discussion, this thesis aims first to explore critically the subject of functional characterisations of biological phenomena, and second, the metaphysical basis of modern science. Its chief contributions to the philosophical function debate reside in proposing novel arguments in justification of what I consider is an improved formulation of an attempted definition of biological function, in which teleological causal powers are explicitly recognised and accommodated in functional explanation. Moreover, this thesis attempts a naturalistic reconstruction of the metaphysical entailments of the real causality of a whole
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- Date Issued: 2020
A framework for scoring and tagging NetFlow data
- Authors: Sweeney, Michael John
- Date: 2019
- Subjects: NetFlow , Big data , High performance computing , Event processing (Computer science)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65022 , vital:28654
- Description: With the increase in link speeds and the growth of the Internet, the volume of NetFlow data generated has increased significantly over time and processing these volumes has become a challenge, more specifically a Big Data challenge. With the advent of technologies and architectures designed to handle Big Data volumes, researchers have investigated their application to the processing of NetFlow data. This work builds on prior work wherein a scoring methodology was proposed for identifying anomalies in NetFlow by proposing and implementing a system that allows for automatic, real-time scoring through the adoption of Big Data stream processing architectures. The first part of the research looks at the means of event detection using the scoring approach and implementing as a number of individual, standalone components, each responsible for detecting and scoring a single type of flow trait. The second part is the implementation of these scoring components in a framework, named Themis1, capable of handling high volumes of data with low latency processing times. This was tackled using tools, technologies and architectural elements from the world of Big Data stream processing. The performance of the framework on the stream processing architecture was shown to demonstrate good flow throughput at low processing latencies on a single low end host. The successful demonstration of the framework on a single host opens the way to leverage the scaling capabilities afforded by the architectures and technologies used. This gives weight to the possibility of using this framework for real time threat detection using NetFlow data from larger networked environments.
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- Date Issued: 2019
Exploring the possibility of integrating traditional music and dance into the design and delivery of lessons on the concepts of echo and waves in the grade 10 Physical Science sound topic
- Authors: Liveve, Angelius Kanyanga
- Date: 2017
- Subjects: Student-centered learning Namibia , Culturally relevant pedagogy Namibia , Science Study and teaching (Secondary) Namibia , Dance in education Namibia , Music in education Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/13356 , vital:21826
- Description: Before Namibian independence in 1990, teaching was mostly characterized by teacher-centred pedagogies in which teachers were perceived as the main sources of knowledge. This resulted in learners being passive recipients of such unquestioned knowledge. After independence and to address this, a new educational system was introduced which promoted learner-centred education (LCE) pedagogy. Despite these grand ideals, educational changes in sub-Saharan Africa form a complex issue involving tensions between policy formulation and implementation. This presents Namibian teachers with some challenges in enacting LCE pedagogies. One of these challenges is to find ways to motivate learners and to assist their learning by finding relevant and interesting connections between subject topics and their own experiences and everyday culture outside the classroom. An inability to enact the new curriculum results in learners performing poorly in subjects such as Physical Science. Against this backdrop, this study sought to explore whether or not the integration of traditional music and dance into the design and delivery of lessons on the concepts of echo and waves could influence grade 10 Physical Science learners’ sense making and dispositions towards science. This study was underpinned by an interpretive paradigm. It was informed and guided by the socio-cultural theory as my theoretical framework. The study was carried out with a grade 10 Physical Science class consisting of 30 learners at Lyambombla Combined School (pseudonym) in the Kavango West Region in the northern part of Namibia. Data were generated through diagnostic and summative tests, interviews and lesson observations incorporating traditional music and dance. The findings of the study showed that learners’ sense making and dispositions toward science were positively influenced through traditional music and dance. The study thus recommends the incorporation of indigenous ways of knowing in order to enhance meaning making in science classrooms.
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- Date Issued: 2017
Real-time audio spectrum analyser research, design, development and implementation using the 32 bit ARMR Cortex-M4 microcontroller
- Authors: Just, Stefan Antonio
- Date: 2017
- Subjects: Spectrum analyzers , Sound -- Recording and reproducing -- Digital techniques , Real-time data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/50536 , vital:25997
- Description: This thesis describes the design and testing of a low-cost hand-held real-time audio analyser (RTAA). This includes the design of an embedded system, the development of the firmware executed by the embedded system, and the implementation of a real-time signal processing algorithms. One of the objectives of this project was to design an alternative low-cost audio analyser to the current commercially available solutions. The device was tested with the audio standard test signal (pink noise) and was compared to the expected at-spectrum response corresponding to a balanced audio system. The design makes use of an 32-bit Reduced Instruction Set Computer (RISC) processor core (ARM Cortex-M4), namely the STM32F4 family of microcontrollers. Due to the pin compatibility of the microcontroller (designed and manufactured by STMicroelectronics), the new development board can also be upgraded with the newly released Cortex-M7 microcontroller, namely the STM32F7 family of microcontrollers. Moreover, the low-cost hardware design features 256kB Random Access Memory (RAM); on-board Micro-Electro-Mechanical System (MEMS) microphone; on-chip 12-bit Analogue-to-Digital (A/D) and Digital-to-Analogue (D/A) Converters; 3.2" Thin-Film-Transistor Liquid-Crystal Display (TFT-LCD) with a resistive touch screen sensor and SD-Card Socket. Furthermore, two additional expansion modules were designed and can extend the functionality of the designed real-time audio analyser. Firstly, an audio/video module featuring a professional 24-bit 192kHz sampling rate audio CODEC; balanced audio microphone input; unbalanced line output; three MEMS microphone inputs; headphone output; and a Video Graphics Array (VGA) controller allowing the display of the analysed audio spectrum on either a projector or monitor. The second expansion module features two external memories: 1MB Static Random Access Memory (SRAM) and 16MB Synchronous Dynamic Random Access Memory (SDRAM). While the two additional expansion modules were not completely utilised by the firmware presented in this thesis, upgrades of the real-time audio analyser firmware in future revisions will provide a higher performing and more accurate analysis of the audio spectrum. The full research and design process for the real-time audio analyser is discussed and both Problems and pitfalls with the final implemented design are highlighted and possible resolutions were investigated. The development costs (excluding labour) are given in the form of a bill of materials (BOM) with the total costs averaging around R1000. Moreover, the additional VGA controller could further decrease the overall costs with the removal of the TFT-LCD screen from the audio analyser and provided the external display was not included in the BOM.
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- Date Issued: 2017
Selected physiological and perceptual responses of batsmen during a simulated one day international century : impact on performance
- Authors: Pote, Lee
- Date: 2013 , 2013-04-02
- Subjects: Cricket -- Batting , Sports -- Physiological aspects , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5097 , http://hdl.handle.net/10962/d1001650
- Description: Background: Very few studies have examined the demands of prolonged batting on physical, psychophysical and performance responses. Objective: The purpose of this study was therefore to determine the physiological and perceptual responses of batsmen scoring a simulated One Day International century. Furthermore, the impact that these responses had on batting performance were also measured. Methods: Seventeen male cricketers currently playing for Rhodes University or the country districts side, performed a simulated bating innings (BATEX©), typical of scoring a One Day international century. The BATEX© protocol consisted of six, five over stages (21 minutes each), with each stage matched to a specific phase of play where batsmen were encouraged to bat with the mindset of that phase. During stages one, three and five players ran at a “self-selected cruise pace” whereas during stages two, four and six players were required to run at maximum speed. At set intervals, selected physiological, perceptual and performance measures were recorded. Results: Most physiological responses increased and decreased accordingly with the low and high intensity stages with the exception of respiratory exchange ratio and core temperature responses. Mean physiological responses however, showed a progressive rise over time. Central ratings of perceived exertion increased as a function of intensity and duration. Sprint times got slower as the protocol progressed, while accuracy (impact accuracy) improved significantly (p<0.05) after stage one and then stabilised for the remainder of the protocol. Conclusion: The simulated batting protocol significantly impacted the physiological and perceptual responses over time. This was due to both the intensity and the duration of the work-bout. Furthermore, the increased physiological load placed on the batsmen significantly impacted the physical performance of the batsmen. An increase in sprint times (players getting slower) towards the end of the protocol may indicate the presence of physical fatigue. This physical fatigue did not however seem to impact the batsmen cognitively as accuracy improved after the first stage and then remained constant over time.
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- Date Issued: 2013
A journey with an abused child : a non-directive play therapy perspective
- Authors: Currin, Lisa Natalie
- Date: 2006
- Subjects: Play therapy -- South Africa , Child sexual abuse -- South Africa -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9847 , http://hdl.handle.net/10948/434 , Play therapy -- South Africa , Child sexual abuse -- South Africa -- Psychological aspects
- Description: The extensive amount of research conducted in the field of family violence internationally indicates that child abuse has a detrimental effect on both the physical and emotional development of children as well as having a profound effect on an individual’s psychological development and functioning in adult life. The aim of this research study was to describe the therapeutic process that unfolded with a seven year old allegedly abused female client within the framework of non-directive play therapy. The case was further contextualised utilising Erik Erikson’s theory of psychosocial development. This study served to broaden the body of psychotherapeutic knowledge by means of meaningful qualitative enquiry. The client was referred for therapy because of severe emotional and behavioural problems following the alleged sexual abuse. The client was seen over a period of eight months and this included 11 sessions of non-directive play therapy, three parent interviews and psychometric assessments conducted by a colleague. The case study method was utilised in this study. To achieve the aim of the research, the methodology of choice was the descriptive dialogic case study. A purposive sampling technique was used in the selection of the research subject for this study. The data collection and analysis were conducted according to Yin’s (1994) analytical generalisation, which consists of two main strategies: (a) using a theoretical framework as a guide to determine what data is relevant; and (b) developing a matrix as a descriptive framework for organising and integrating the data. Furthermore, the process of data analysis was aided by the use of guidelines proposed by Irving Alexander (1988) with Axline’s non-directive play therapy and Erikson’s theory of psychosocial development as the theoretical frameworks. The findings of this study suggest that plotting the play therapy sessions according to the framework of the four stages of play therapy was a particularly useful tool to monitor Michelle’s progression through the therapeutic process. This can be seen as a valuable application of a tool which can be used within the non-directive play therapy approach. Contextualising Michelle’s development according to the stages of Erikson’s theory of psychosocial development was also found to be a valuable endeavour. According to her chronological age, Michelle should have been in the fourth stage of industry versus inferiority, but in reality Michelle was still struggling to strike a healthy balance between the terms of conflict of trust versus mistrust issues of the first stage. From a therapeutic point, this was an important exercise as it helped to inform the therapist and consequently, the therapeutic process. This research undertaking can be recognised as a positive demonstration of the value of non-directive play therapy (Virginia Axline) and Erik Erikson’s theory of psychosocial development in the therapeutic process. In addition, this study has served to facilitate a more holistic understanding of the case study approach to research. Recommendations regarding future research undertakings that utilise the case study approach and methodology have been made. Key concepts: child abuse; family violence; non-directive play therapy; Erik Erikson’s theory of psychosocial development; analytical generalisation; case study research.
- Full Text:
- Date Issued: 2006
The effect of selenium in the detoxification of the microcystin hepatotoxins
- Authors: Downs, Kerry
- Date: 2002
- Subjects: Cynaobacterial toxins , Microcystins , Selenium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11070 , http://hdl.handle.net/10948/284 , Cynaobacterial toxins , Microcystins , Selenium
- Description: Blooms of cyanobacteria have been known to cause illness in humans and death in wild and domestic animals. One of the toxins produced by cyanobacteria is microcystin, which is a potent hepatotoxin. Microcystin is taken up by bile acid transporters in the intestine and transported into the liver. After exposure to acute doses of microcystin, severe haemorrhage has been observed along with apoptotic and necrotic hepatocytes. The cytoskeletal structure of the hepatocytes is disrupted and oxidative stress is induced. Selenium, a known anti-oxidant, has been shown to induce increased activity of glutathione peroxidase. Glutathione peroxidase removes peroxides from cells protecting them from oxidative stress. This study set out to determine if selenium could play a role in preventing the damage to mice livers due to microcystin toxin. The protective role of selenium was explored in three main studies: in the first study, the ability of selenium to increase the survival time of mice exposed to a lethal dose of toxin was determined. In the second study the mice were exposed to sublethal chronic doses of toxin over 30 days. The ability of selenium to minimise liver damage under these conditions was determined. The final study investigated the mechanism of the protective effect of selenium. The results of the first study suggested that selenium could extend survival time. In the second study the selenium supplemented mice showed a reduction in the extent of the increase in liver weight and a decrease in the amount of lipid peroxidation induced compared to the mice that received only toxin. The histology of the selenium supplemented mice also showed a decrease in the severity and amount of morphological changes in the liver. The third study indicated that the protection shown by selenium might be mediated by an increase in the glutathione peroxidase (GPX) activity in selenium supplemented mice. This increase in GPX activity would increase the removal of the lipid hydroperoxides and prevent the damage they would cause in the cell. A further result indicated an increase in glutathione S-transferase in only the toxin control mice when compared to the selenium supplemented and control mice. ii In conclusion selenium offers protection against microcystin but further studies need to be done to provide statistically valid results to clarify the level of protection.
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- Date Issued: 2002
A phenomenological explication of the experience of counselling chronic callers in Life Line
- Authors: Matthis, Kenneth Skeen
- Date: 1983
- Subjects: Life Line Movement , Hotlines (Counseling)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3135 , http://hdl.handle.net/10962/d1006893 , Life Line Movement , Hotlines (Counseling)
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- Date Issued: 1983