Mediating learning of sound through cultural music and dance stories to Grade 4 farm school learners
- Authors: Tshitshi, Hlengiwe
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463647 , vital:76428
- Description: The current South African Natural Science and Technology (NS-Tech) curriculum for grades 4–9 encourages teachers to integrate Indigenous Knowledge (IK) into their teaching. By doing so, it is hoped that this would contextualise and make science relevant to learners. However, the contradiction is that IK is hardly discussed in the curriculum and there are no clear guidelines on how to integrate it. It is against this background that in this study I used stories about cultural beliefs and practices on traditional music and dance to support Grade 4 NS-Tech from a farm school talking about and making sense of the topic of sound. This study is underpinned by the interpretivist and Indigenous research paradigms. Within the Indigenous research paradigm, I focused on the Ubuntu perspective. A qualitative case study research design was employed, and the study was conducted in the Sarah Baartman District of the Eastern Cape. Four Grade 4 learners and four Indigenous Knowledge Custodians who were all family members were participants in this study. In addition, I invited an NS-Tech teacher to be my critical friend in this study. A focus group interview (sharing circle), participatory and lesson observations and learners’ journal reflections were employed to gather data. Vygotsky’s sociocultural theory together with Ogunniyi’s contiguity argumentative theory were used as lenses to analyse data. A thematic approach to data analysis was employed to come up with sub-themes. Thereafter, common sub-themes were subsequently combined to form themes. The findings of this study revealed that the following factors can significantly enable/constrain the ability of Grade 4 Natural Sciences and Technology learners from a farm school to comprehend and engage with the topic of sound: (1) integration of IK into science lessons, (2) Experiential learning through hands-on activities, (3) Community involvement in knowledge acquisition, and (4) Emotional effect of loud sounds. In addition, the contribution of Indigenous Knowledge Custodians facilitated a notable enhancement in learners’ dialogue and understanding of sound. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
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- Date Issued: 2024-10-11
Spatiotemporal ecology and potential displacement of white sharks in southern Africa
- Authors: Towner, Alison
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432275 , vital:72857
- Description: Restricted access. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
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- Date Issued: 2023-10-13
An investigation of the English language demands of mathematical texts on data handling used in intermediate phase mathematics
- Authors: Jones, Angela Peta
- Date: 2022-10-14
- Subjects: Mathematics Study and teaching (Elementary) South Africa , Middle school education South Africa , Information storage and retrieval systems Mathematics , Language complexity , Textbooks Readability , Language arts Correlation with content subjects South Africa , Content area reading South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405259 , vital:70155
- Description: In the Intermediate Phase the majority of South African learners are transitioning from learning in their mother tongue to learning in English as well as from learning to read to reading to learn, and this is a major challenge. Textbooks are a key mediating artefact in the learning of mathematics and they present a challenge to the learner in terms of the language comprehension demands The data handling sections of mathematics textbooks are particularly dense in text. This is an important part of the mathematics curriculum as it is the beginning of statistical literacy learning. We need to be able to question, evaluate claims based on data, create arguments we can defend and use data meaningfully, it is thus crucial that learners acquire statistical literacy. This research sets out to examine the text in the data handling sections of four Intermediate Phase Mathematics book series in order to answer the following research question: What are the language comprehension demands of English mathematical texts on data handling that are used in South African Intermediate Phase Mathematics? The theories framing the study are Vygotsky’s sociocultural theory and Cummins’ second language acquisition theory. It is an interpretivist mixed method case study that takes the form of a document analysis.. The findings indicate that many units in the books analysed have a higher readability level than the grade level and will thus present a challenge to learners in terms of their ability to access the mathematical content. An analysis of the linguistic complexity revealed that the features contributing most to the complexity of the texts included words with seven or more letters, prepositional phrases, infinitives, complex verbs and complex/compound sentences. An examination of the non-textual elements revealed that most of them are accurate, connected, concise, contextual and these add to the comprehensibility although there were a few which could be possibly be distractors. It is hoped that the empirical findings of this study, will sensitise educators and publishers involved with the design of textbooks and workbooks to the type of language currently found and that they might give attention to the needs of English language learners when developing these texts. , Thesis (MEd) -- Faculty of Education, Education, 2022
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- Date Issued: 2022-10-14
Fucoidans from South African brown seaweeds: establishing the link between their structure and biological properties (anti-diabetic and anti-cancer activities)
- Authors: Mabate, Blessing
- Date: 2022-10-14
- Subjects: Fucoidan , Diabetes Treatment , Cancer Treatment , Brown algae
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365677 , vital:65775 , DOI https://doi.org/10.21504/10962/365677
- Description: Type 2 diabetes mellitus (T2DM) and cancer are major non-communicable diseases causing a heavy morbidity-mortality and economic burden globally. The therapeutic efforts in managing these diseases are primarily chemotherapeutic and are associated with demerits, including side effects and toxicity, limiting the prescribed amounts. These dosage limits may cause drug resistance, another major challenge in maintaining quality global health. The pursuit of novel natural bioproducts is a reasonable strategy to add to the arsenal against T2DM and cancer. Fucoidans, sulphated fucose polysaccharides abundant in brown seaweeds, have recently become popular for their biological activities, including anti-diabetic and anti-cancer properties. However, endemic South African brown seaweeds have not been adequately explored. Therefore, this study sought to characterise fucoidans extracted from South African brown seaweeds and elucidate their structure to their biological activities. Also, this study highlighted carbohydrate and glucose metabolism as major target processes in the control efforts of T2DM and cancer using fucoidans. Harvested brown seaweeds were identified as Ecklonia radiata and Sargassum elegans. E. maxima was kindly donated by KelpX. The fucoidans were then extracted using hot water, EDTA assisted, and acid extraction protocols. The integrity of the extracted fucoidan was confirmed through structural analysis using FTIR, NMR and TGA. The fucoidan extracts were then chemically characterised to determine their carbohydrate and monosaccharide composition and sulphate content. The characterised fucoidans were profiled for inhibiting the major amylolytic enzymes, namely α-amylase and α-glucosidase. The mode of inhibition by fucoidans and synergy experiments with the commercial anti-diabetic drug acarbose were also investigated. Furthermore, the fucoidans were screened for potential anti-cancer activities on the human colorectal HCT116 cancer cell line. The cytotoxicity of fucoidans was quantified using the resazurin assay. The effect of fucoidan on HCT116 cell adhesion on the tissue culture plastic was also investigated using the crystal violet-based cell adhesion assay. In addition, cancer antimigration properties of fucoidans were also investigated using 2D wound healing and 3D spheroid-based assays. Furthermore, the long-term survival of HCT116 cells was investigated through the clonogenic assay after treatment with fucoidans. Lastly, glucose uptake and lactate export assays revealed the influence of fucoidan on glucose uptake and the glycolytic flux of HCT116 cells. Fucoidans were successfully extracted with a yield between 2.2% and 14.2% on a dry weight basis. EDTA extracts produced the highest yields than the water and the acid extracts. Ecklonia spp. fucoidans displayed the highest total carbohydrate content, with glucose and galactose being the major monosaccharides. S. elegans and commercial Fucus vesiculosus had lower carbohydrate contents but contained more sulphates than the Ecklonia spp. fucoidans. Furthermore, the extracted fucoidan contained little to no contaminants, including proteins, phenolics and uronic acids. In addition, the extracted fucoidans were determined to be >100 kDa through ultracentrifugation. Mass spectrometry also detected the most abundant peak for all fucoidans to be around 700 Da (m/z). Extracted fucoidans inhibited the activity of α-glucosidase more strongly than the commercial anti-diabetic agent acarbose but were inactive on α-amylase. Fucoidans were also shown to be mixed inhibitors of α-glucosidase. Compellingly, fucoidans synergistically inhibited α-glucosidase in combination with the anti-diabetic agent acarbose, highlighting prospects for combination therapy. Finally, fucoidans demonstrated some anti-proliferative characteristics on HCT116 cancer cells by inhibiting their ability to adhere to the tissue culture plate matrix. Furthermore, some fucoidan extracts inhibited the migration of HCT116 cancer cells from 3D spheroids. Some of our fucoidan extracts also inhibited HCT116 colony formation, demonstrating inhibition of long-term cell survival. The E. maxima water extract also inhibited glucose uptake by HCT116 cells, thereby influencing the glycolytic flux. In conclusion, biologically active fucoidans were successfully extracted from South African brown seaweeds. These fucoidans demonstrated anti-diabetic and anti-cancer properties, revealing their relevance as potential drugs for these diseases. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
Synthesis, In-Silico molecular modelling and biological studies of 1,4-Dihydroxyanthraquinone and its derivatives
- Authors: Kisula, Lydia Mboje
- Date: 2022-10-14
- Subjects: Computer simulation , Molecules Models , Dihydroxyanthraquinone , Trypanosomiasis , Leishmaniasis , Docking
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365828 , vital:65793 , DOI https://doi.org/10.21504/10962/365828
- Description: This current study of investigation reports on the synthesis of 1,4-dihydroxyanthraquinone and its derivatives on explorations of their medicinal potential. The study initially aimed to synthesize an analogue of a natural anthraquinone, 1,3,6-trihydroxy-7-((S)-1- hydroxyethyl)anthracene-9,10-dione 5 using Friedel-Crafts acylation of phthalic anhydride and a benzene derivative. Synthetic transformation of anacardic acid 63, obtained as a by- product of the cashew industry successfully afforded 4-ethoxyisobenzofuran-1,3-dione 89. However, when attempted to couple 4-ethoxyisobenzofuran-1,3-dione 89 with 2- hydroxyacetophenone 91 in a Friedel-Crafts acylation manner to form 2-acetyl-1,8- dihydroxyanthracene-9,10-dione 87 the reaction did not work efficiently. A simple derivative of benzene which is; benzene-1,4-diol 102 was reacted instead with 3-ethoxyphthalic acid 71 and isobenzofuran-1,3-dione 96 to form 1,4,5-trihydroxy anthraquinone 72 and 1,4- dihydroxyanthraquinone 42, respectively. A modified Marschalk reaction was then used to introduce the hydroxyl alkyl group to 1,4-dihydroxy anthraquinone 42, which allowed further elaboration of the hydroxyl-substituent in moderate to good yields (22-80%). A molecular docking study was performed using Schrödinger software to predict the binding affinity of the test compounds to the target protein trypanothione reductase (PDB ID: 6BU7). An in-vitro screening of 1,4-dihydroxyanthraquinone derivatives and some selected precursors for antitrypanosomal, antiplasmodial, antibacterial, and cytotoxicity activities produced encouraging results. Derivatives of anacardic acid and cardanol from CNSL were found to have moderate activity against trypanosomes with no activity against Plasmodium falciparum. Almost 63% of synthesized 1,4-dihydroxyanthraquinone derivatives displayed activity against trypanosomes. The in-vitro evaluation and the in silico molecular docking studies revealed that 1,4-dihydroxyanthraquinone derivatives can be potential drug-like candidates active against T.brucei parasites (IC50 = 0.70-1.20 μM). Only four 1,4- iv dihydroxyanthraquinone derivatives with thiosemicarbazone, chloride, pyrrole, and diethanolamine functionality displayed activity against Plasmodium falciparum (IC50 = 3.17- 14.36 μM). In-vitro evaluated of test compounds against antibacterial screen and cytotoxicity effects significantly showed that 2-hydroxy-6-pentadecylbenzoic acid 63a and 2-((2- chlorophenyl)(piperazin-1-yl) methyl)-1,4-dihydroxyanthracene-9,10-dione 78 have potency against Staphylococcus aureus and reduced the viability of the cells below 20% at an initial concentration of 50 μg/mL. Only 1,4-dihydroxyanthraquinone derivatives with thiosemicarbazone 76, piperazine 78, and diethanolamine 80 motifs were active against HeLa cells and reduced the viability of cells below 20% at a concentration of 50 μg/mL. In conclusion, this current reported study has generated useful knowlege on the applicability of the agro-waste CNSL as an agent active against trypanosomiasis but also as a low-cost starting material to synthesize hydroxy anthraquinones. The study has further given an overview to the understanding of the medicinal value 1,4-dihydroxyanthraquinone derivatives as promising candidates towards developing drugs suitable for treating neglected tropical diseases particularly trypanosomiasis. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
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- Date Issued: 2022-10-14
Building the field component of a smart irrigation system: A detailed experience of a computer science graduate
- Authors: Pipile, Yamnkelani Yonela
- Date: 2021-10
- Subjects: Irrigation efficiency Computer-aided design South Africa , Irrigation projects Computer-aided design South Africa , Internet of things , Machine-to-machine communications , Smart water grids South Africa , Raspberry Pi (Computer) , Arduino (Programmable controller) , ZigBee , MQTT (MQ Telemetry Transport) , MQTT-SN , XBee
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191814 , vital:45167
- Description: South Africa is a semi-arid area with an average annual rainfall of approximately 450mm, 60 per cent of which goes towards irrigation. Current irrigation systems generally apply water in a uniform manner across a field, which is both inefficient and can kill the plants. The Internet of Things (IoT), an emerging technology involving the utilization of sensors and actuators to build complex feedback systems, present an opportunity to build a smart irrigation solution. This research project illustrates the development of the field components of a water monitoring system using off the shelf and inexpensive components, exploring at the same time how easy or difficult it would be for a general Computer Science graduate to use hardware components and associated tools within the IoT area. The problem was initially broken down through a classical top-down process, in order to identify the components such as micro-computers, micro- controllers, sensors and network connections, that would be needed to build the solution. I then selected the Raspberry Pi 3, the Arduino Arduino Uno, the MH-Sensor-Series hygrometer, the MQTT messaging protocol, and the ZigBee communication protocol as implemented in the XBee S2C. Once the components were identified, the work followed a bottom-up approach: I studied the components in isolation and relative to each other, through a structured series of experiments, with each experiment addressing a specific component and examining how easy was to use the component. While each experiment allowed the author to acquire and deepen her understanding of each component, and progressively built a more sophisticated prototype, towards the complete solution. I found the vast majority of the identified components and tools to be easy to use, well documented, and most importantly, mature for consumption by our target user, until I encountered the MQTT-SN (MQTT-Sensor Network) implementation, not as mature as the rest. This resulted in us designing and implementing a light-weight, general ZigBee/MQTT gateway, named “yoGa” (Yonella's Gateway) from the author. At the end of the research, I was able to build the field components of a smart irrigation system using the selected tools, including the yoGa gateway, proving practically that a Computer Science graduate from a South African University can become productive in the emerging IoT area. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
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- Date Issued: 2021-10
Understanding the replication biology of Providence virus: elucidating the function of non-structural proteins
- Authors: Nakayinga, Ritah
- Date: 2014
- Subjects: Insects Viruses , Viruses Reproduction , Tombusviridae , RNA viruses , RNA polymerases
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/193930 , vital:45408
- Description: Tetraviruses are non-enveloped, small insect RNA viruses with a single stranded positive RNA genome that is either monopartite or bipartite. Providence virus (PrV) is the only member of the three tetravirus families with a viral replicase similar to the replicases of tombusviruses and umbraviruses. The principle aim of this thesis was to study PrV replication, focusing on subcellular localization and potential interactions between PrV replication proteins. The first objective of this study was to generate an anti-p104 antibody that does not cross-react with p40. Expression of the C-terminal portion of p104 in E. coli resulted in no detectable protein. Further expression in an insect cell based expression system resulted in the production of an insoluble protein. Attempts to improve protein solubility with a range of solubilization treatments were unsuccessful. Bioinformatic analysis was used to detect an antigenic region at the C-terminus of p104 and the peptide was used to raise anti-p104 antibodies. These antibodies did not detect native protein by western blot detection however they were used for immunoprecipitation. The establishment of the subcellular localization of PrV required two approaches; immunofluorescence in persistently infected Helicoverpa zea MG8 cells using antip40 and anti-dsRNA antibodies and the expression of EGFP-replicase fusion protein in Spodoptera frugiperda Sf9 cells. Replication of PrV was found to take place in cytosolic punctate structures. Co-immunoprecipitation experiments revealed that p40 self-interacts and interacts with p104. Bioinformatic analysis of PrV p104 suggests that the RdRp is similar to viral RdRps of the carmo-like supergroup II. Potential RNA binding regions are present within p104. A potential p40 interaction domain that shares hydrophilic and surface exposed properties with the TBSV p33 interaction domain is present. A putative arginine-rich region and disordered C-terminal region is present in p130. In conclusion, PrV p104 is the viral replicase. The resemblance of the expression strategy and putative functional domains with tombusviruses and umbraviruses suggest that PrV replication is related to the replication system of the tombusviruses and umbraviruses. This has led to propose that tetravirus replication strategies are diverse and raises questions on the origin and evolution of PrV. , Thesis (PhD) -- Faculty of Science, Biochemistry, Microbiology and Biotechnology, 2014
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- Date Issued: 2014