Bioactivity evaluation of manno-oligosaccharides produced from spent coffee grounds using a Bacillus sp. derived endo-1,4-β-mannanase
- Authors: Magengelele, Mihle
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365233 , vital:65719
- Description: Thesis embargoed. Possible release date set for early 2024. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
Characterisation of two novel ferrocenyl benzoxazines as in vitro triple-negative breast cancer inhibitors
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
Contextualising job satisfaction amongst lowest paid support staff in a Higher Education institution
- Authors: Madito, Gotlannamang Moloiesi Boipelo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405984 , vital:70225
- Description: Thesis embargoed. To be relased in 2024. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
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- Date Issued: 2022-10-14
Country risk and stock market volatility in Africa: Measuring the contribution of political and economic risk factors
- Authors: Hoveni, Jamela Basani
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405445 , vital:70172
- Description: Thesis embargoed. To be released in 2025. , Thesis (PhD) -- Faculty of Commerce, Economics and economic History, 2022
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- Date Issued: 2022-10-14
Development of biosensor systems for the detection of anti-cancer drugs and prostate cancer
- Authors: Mwanza, Daniel
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365929 , vital:65803
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
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- Date Issued: 2022-10-14
Dual and targeted photodynamic therapy ablation of bacterial and cancer cells using phthalocyanines and porphyrins in the presence of carbon-based nanomaterials
- Authors: Openda, Yolande Ikala
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365945 , vital:65804 , DOI https://doi.org/10.21504/10962//365946
- Description: Phthalocyanines (Pcs) and porphyrins bearing substituents that possess antibacterial/anticancer properties are used as photosensitizers (PS) for the first time in the work. For targeting specificity and improved photoactivity, the PSs were afterward functionalized with carbon nanomaterials such as graphene quantum dots (GQDs) and detonation nanodiamonds (DNDs) via covalent conjugation (amide or ester bonds) or by non-covalent conjugation (π-π stacking and electrostatic interactions). Furthermore, the PSs-DNDs nanoconjugates were conjugated to either chitosan-capped silver nanoparticles (CSAg) via amide bonds or to the bare silver nanoparticles (Ag NPs) using the silver- nitrogen affinity. The as-synthesized nanoconjugates were also fully characterized by spectroscopic and microscopic methods together with thermal analysis. The potential photocytotoxicity of the complexes alone and their nanoconjugates against S. aureus and/or E. coli planktonic and biofilm cultures has been evaluated in vitro. Compared to the non- quaternized PSs, the cationic analogs exhibited a higher photodynamic inactivation against the planktonic cells with log10 reduction values above 9 in the viable count using a concentration of ca. 1.25 μM following 30 min exposure to light (Light dose: 943 J/cm2 for Pcs and 250 mW/cm2 for porphyrins). Whereas, at a concentration of ca. 100 μM the cationic PSs showed complete eradication of biofilms upon 30 min exposure to light. As a result of conjugation to carbon-based nanomaterials and silver nanoparticles, the compounds proved to be more effective as they exhibited stronger antibacterial and anti-biofilm activities on the multi-drug resistant bacteria strains due to synergetic effect, compared to PSs alone. This suggests that the newly prepared nanohybrids (PS concentration ca. 100 μM) could be used as potential antimicrobial agents in the treatment of biofilm-related infections. The target nanoconjugates showed all the advantages of two different groups existing on a single entity. In light of the potential advantages of combined chemotherapy and photodynamic antimicrobial chemotherapy (PACT), this work reports for the first time the use of PACT-ciprofloxacin (CIP) dual therapy using selected indium quaternized PSs which showed higher photoactivity with complete eradication of both Gram-positive and Gram-negative bacteria biofilms at concentrations of 8 μM of PS versus 2 μg/mL of the antibiotic following 15 min irradiation time (light dose: 471 J/cm2 for Pcs and fluence: 250 mW/cm2 for porphyrins) on S. aureus. Whereas the total killing of E. coli was obtained when combining 8 or 16 μM of PS combined with 4 μg/mL of CIP. The combined treatment resulted in the complete eradication of the matured biofilms with the highest log10 reduction values of 7.05 and 7.20 on S. aureus and E. coli, respectively. Used as a model, positively charged dimethylamino-chalcone Pcs also exhibited interesting photodynamic therapy (PDT) activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 μM, respectively following 15 min irradiation. Additionally, the TD-B3LYP/LanL2DZ calculations were run on the dimethylaminophenyl- porphyrins to compare the singlet excitation energies of quaternized and non-quaternized porphyrins in vacuo. the study shows excellent agreement between time-dependent density- functional theory (TD-DFT) exciting energies and the experimental S1>S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-Vis spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO-1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
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- Date Issued: 2022-10-14
Evaluating the role of Stress Induced Phosphoprotein 1 isoforms in Kaposi's Sarcoma-Associated Herpesvirus biology
- Authors: Ruck, Duncan Kyle
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365280 , vital:65723
- Description: Thesis embargoed. Possible release date set for early 2025. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
Evaluating the trophic ecology and feeding habits of three divergent lineages of Sandelia bainsii (Teleostei: Anabantidae), from the Eastern Cape Rivers using stable isotope analysis
- Authors: Nkomo, Thulisile
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/364984 , vital:65667
- Description: Despite supporting a disproportionately large fraction of the global biodiversity, freshwater ecosystems are ranked as the most highly threatened habitats on the planet, ahead of both terrestrial and marine ecosystems. Many regions are still characterised by limited knowledge regarding the taxonomy and ecology of freshwater fish taxa. The need for ecological information is increasingly becoming important due to the discovery of new species and unique lineages, which require conservation management. The aim of this study was thus to evaluate the trophic ecology and feeding habits of the three recently described and divergent Sandelia bainsii lineages, namely Sandelia sp. ‘bainsii Kowie’ from the Great Fish River, Sandelia sp. ‘bainsii Keiskamma’ found in the Keiskamma River, and Sandelia sp. ‘bainsii Buffalo’ confined to the Buffalo River system in the Amathole-Winterberg freshwater ecoregion in the Eastern Cape Province, South Africa. Based on the allopatric distribution and the generalist feeding habits of these lineages, this thesis postulated that these three lineages were likely to show similar trophic ecology patterns, different dietary composition and as a result would have variable trophic positioning in the different river systems. Therefore, the primary objectives were to use stable isotope analysis to (1) evaluate the food web patterns of the river systems where the three S. bainsii lineages occurred, and (2) determine dietary source contributions for the three lineages using isotope mixing models. The results revealed general variability and significant differences in the δ13C and δ¹⁵N values for the different basal resources, macroinvertebrates and fish community across the different headwater streams. Within and across the different rivers, the S. bainsii lineages exhibited variable isotopic niche sizes, which appeared to coincide with the variation in the isotopic composition of the individual communities. Furthermore, these lineages did not exhibit any discernible patterns in their interspecific interactions in different habitats. This suggests that these lineages’ isotopic niche patterns were largely influenced by spatial differences in both trophic resources and probable interactions with contraspecifics. Assessment of trophic positions of S. bainsii lineages showed that the three lineages had higher trophic positions than other co-occurring species at most sites, except in the Buffalo River. This suggest that the different lineages were generally top predators in the different river systems. Although S. ‘bainsii Buffalo’ had a lower trophic position compared to other co-occurring species, its trophic position was generally characterised by high uncertainty, indicating that this lineage was likely influenced by the occurrence of diet sources that had highly variable stable isotope values. Findings from stable isotope mixing models revealed that the diet sources varied from the dominance of either single diet source in the Fairburn and Tyume 1 River to the importance of multiple prey sources from the Lushington and Kat River system. This suggests that despite being a top predator at most sites, the diet sources for the different lineages were highly variable. The patterns observed in this study did not appear to be attributed to species divergence possibly caused by allopatric speciation, but rather differences in food web characteristics of the river systems, as well as the lineages interspecific relationships and their generalized feeding strategies. Understanding the trophic dynamics of these lineages will assist in implementing effective conservation strategies and policies dealing with narrowly distributed species that are threatened by habitat fragmentation and invasion of piscivorous fish. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
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- Date Issued: 2022-10-14
Exploration of remote work and wellbeing of academics in a South African tertiary institution
- Authors: Chikutu, Michelle
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405963 , vital:70223
- Description: Thesis embargoed. To be released in 2024. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
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- Date Issued: 2022-10-14
Exploring integration for the topic of stoichiometry in South African natural sciences and physical sciences school curricula
- Authors: Mgolozeli, Kwanele
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405330 , vital:70162
- Description: Many developing countries, including South Africa, have identified the provision and implementation of strong science curricula as central to their developmental needs. Stoichiometry is a fundamental chemistry topic because the concepts involved form the basis of later topics such as chemical equilibrium, rates of reactions, redox reactions, and acid-base reactions. School students consistently demonstrate lack of understanding of stoichiometry-related concepts and skills such as the particulate nature of matter and related mathematical problem-solving. The poor performance of high school students in central science topics such as stoichiometry is problematic for their further study of chemistry and for the country meeting its need for science graduates. Successive examiner reports pointed to the lack of integration of stoichiometry concepts across the grades being the main problem. However, no study could be found which explores how stoichiometry is integrated in the South African Natural Sciences and Physical Sciences curriculum across the grades. This provided the rationale for the current study. The case study reported in this thesis thus aimed to explore integration of stoichiometry concepts in South African Natural Sciences and Physical Sciences school curricula. It involved document analysis as the method of collecting data. The research adopted the social realist paradigm, with its realist ontology and relativist epistemology. Legitimation Code Theory provided the theoretical framing. Chemistry concepts that are foundational to the understanding of stoichiometry according to literature, were chosen as root concepts for the concept mapping undertaken to identify types of integration. The concept maps revealed four stoichiometry integration themes: integration of stoichiometry concepts with symbols, integration of stoichiometry concepts with explanations, integration with applications in a chemistry context, and integration with an everyday context. These themes provided integration categories. A semantic gravity translation device was then developed for characterising the types of integration in terms of the degree of contextualisation. The results of this study show that stoichiometry integration of weaker semantic gravity is legitimated more strongly over other semantic gravity codes in the Natural Sciences and Physical Sciences curricula across all grade levels. While this has advantages in terms of knowledge-building potential, the consequence is that the integration occurs at very abstract levels that are far removed from learners’ everyday lives. The practical implication for curriculum developers involves increasing the instances of integration of stoichiometry concepts at stronger levels of semantic gravity, for a more even semantic gravity range of integration types. Natural Sciences and Physical Sciences teachers also need to source and include real-life examples for explanations and applications of stoichiometry concepts when teaching, in light of current curriculum documents focusing more on abstract forms of integration. Methodologically, this study contributes to the increased utility of semantic gravity through its exploration of integration in relation to knowledge-building potential of curriculum for hierarchical knowledge structures such as chemistry. , Thesis (MEd) -- Faculty of Education, Education, 2022
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- Date Issued: 2022-10-14
Exploring primary school mathematics teachers use of gamification in formative assessment: a case study
- Authors: Simelane, Thando
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405412 , vital:70169
- Description: Thesis embargoed. To be released in 2024. , Thesis (MEd) -- Faculty of Education, Education, 2022
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- Date Issued: 2022-10-14
Exploring the influence of student protests on organisational citizenship behaviour of academics and support mechanisms in higher learning institutions
- Authors: Mayekiso, Sinovuyo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406198 , vital:70248
- Description: Embargoed. To be released in 2024. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
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- Date Issued: 2022-10-14
Global climate justice: the case of climate migrants
- Authors: Van Heerden, Samantha Jane Ashburner
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406749 , vital:70304
- Description: Climate change is predicted to displace thousands of people across the globe. Due to their geographical location and limited resources available for adaptation, this will particularly impact those in developing states, who might have to flee from the growing frequency and severity of rising sea levels, drought and desertification, and acute natural disasters such as floods, wildfires, and hurricanes. This is likely to have pervasive effects on the moral interests of those affected, threatening loss of life, the deterioration of livelihoods, and for small island states even complete or substantial loss of state territory. In this thesis I will argue that we should conceive of this situation as a problem of global justice. Though some argue that questions of justice only arise within the state, I will argue that global economic and political institutions have contributed to the plight of climate migrants, and that following from Darrel Moellendorf’s theory of associational justice, this enduring impact results in an association and duties of justice that transcend state borders. To respect the dignity of climate migrants, such an unjust association needs to be rectified by establishing ethical principles that could be reasonably endorsed by everyone affected. Drawing from Gillian Brock, I will argue that the best way to rectify the situation is through establishing a principle of distributive justice which focuses on ‘agency needs’: needs whose fulfilment is necessary for human agency. Using this framework, I then provide some recommendations of what is owed to climate migrants to achieve justice for them. I also consider how these duties of justice should be distributed, first critiquing a dominant approach that attributes duties primarily to polluters. In the end, I recommend that duties should be dispersed between all those who support the global institutions responsible, those who have been high polluters since 1990, and the most affluent in the world. As the effects of climate change become increasingly pronounced within the next fifty years, establishing what is owed to those displaced is of utmost importance, and I hope this thesis shows how normative philosophy can help us think through these urgent questions. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2022
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- Date Issued: 2022-10-14
Identification and characterisation of microbial communities and their metabolic potential in meltwater ponds, Western Dronning Mau Land, Antarctica
- Authors: Van Aswegen, Sunet
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365723 , vital:65779
- Description: Thesis embargoed. Expected release date early 2024. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
In silico substrate binding profiling for SARS-COV-2 main protease (mpro) using hexapeptide substrates
- Authors: Zabo, Sophakama
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365566 , vital:65760
- Description: COVID-19, as a disease resulting from SARS-CoV-2 infection, and a pandemic has had a devastating effect on the world. There are limited effective measures that control the spread and treatment of COVID-19 illness. The homodimeric cysteine main protease (Mpro) is crucial to the life cycle of the virus, as it cleaves the large polyproteins 1a and 1ab into matured, functional non-structural proteins. The Mpro exhibits high degrees of conservation in sequence, structure and specificity across coronavirus species, making it an ideal drug target. The Mpro substrate-binding profiles remain, despite the resolution of its recognition sequence and cleavage points (Leu-Gln↓(Ser/Ala/Gly)). In this study, a series of hexapeptide sequences containing the appropriate recognition sequence and cleavage points were generated and screened against the Mpro to study these binding profiles, and to further be the basis for efficiency-driven drug design. A multi-conformer hexapeptide substrate library comprising optimised 81000 models of 810 unique sequences was generated using RDKit within the context of python. Terminal capping with ACE and NMe was effected using SMILES and SMARTS matching. Multiple hexapeptides were complexed with chain B of crystallographic Mpro (PDS ID: 6XHM), following the validation of chain B for this purpose using AutoDock Vina at high levels of exhaustiveness (480). The resulting Vina scores ranged between -8.7 and -7.0 kcal.mol-1, and the reproducibility of best poses was validated through redocking. Ligand efficiency indices were calculated to identify substrate residues with high binding efficiency at their respective positions, revealing Val (P3), Ala (P1′); and Gly and Ala (P2′ and P3′) as leading efficient binders. Binding efficiencies were lowered by molecular weight. Substrate recognition was assessed by mapping of binding subsites, and Mpro specificity was evaluated through the resolution of intermolecular interaction at the binding interface. Molecular dynamics simulations for 20 ns were performed to assess the stability and behaviour of 132 Mpro systems complexed with KLQ*** substrates. Principal component analysis (PCA), was performed to assess II protein motions and conformational changes during the simulations. A strategy was formulated to classify and evaluate relations in the Mpro PCA motions, revealing four main clades of similarity. Similarity within a clade (Group 2) and dissimilarity between clades were confirmed. Trajectory visualisation revealed complex stability, substrate unbinding and dimer dissociation for various Mpro systems. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
Investigating the roles of HOP isoforms in KSHV biology
- Authors: Matandirotya, Lorraine Tariro
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365257 , vital:65721
- Description: Thesis embargoed. Possible release date set for early 2025. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
Knowledge of and concern about global biodiversity loss vs local biodiversity loss in the Maputaland-Pondoland-Albany Hotspot (MPA)
- Authors: Toyisi, Zanele Jacqueline
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365025 , vital:65671
- Description: Biodiversity forms the basis of the ecosystem services that society depends on. However, humanity has caused an increase in the extinction rates up to 100 times higher than that of evolutionary background levels. Recent studies found that biodiversity conservation becomes successful when it is grounded in local support. Support for conservation of biodiversity depends on peoples’ knowledge of biodiversity, their attitudes and awareness of the number of species that are present and that are threatened with extinction. However, some studies have shown that the public has little knowledge about the concept of biodiversity and have poor biodiversity identification skills. There is growing concern that people know and are more concerned about global biodiversity loss than what is happening around them locally. The notion that people know and are more concerned about global biodiversity loss rather than local, has not been deeply studied. Most studies have been in developed countries, with limited studies in developing countries and countries that have high diversity such as South Africa. Having accurate knowledge about biodiversity and the environment is said to be the key predictor of intention to change behaviour in relation to biodiversity. Therefore, the purpose of this study was to understand the knowledge and concern (if any) people have of biodiversity at global and local scales. More so, it set out to determine how familiar people are with the term biodiversity, what they consider as forces leading to biodiversity decline, the level of concern that they have for biodiversity loss and if knowledge and concern is influenced by demographic profiles. To achieve this aim, a total of 220 random interviews were conducted in three towns within the Maputaland-Pondoland-Albany Hotspot in South Africa. The results show that respondents are familiar with the term biodiversity. There was a strong relationship between having heard of the term and the ability to define it with 55 % of the respondents aware of it and able to define it. Respondents had moderate knowledge general knowledge related to biodiversity. Gender, education and childhood background did play a role in the knowledge of biodiversity. Women had more knowledge about biodiversity than men, highly educated respondents knew more and the youth knew more than older respondents. The results of this study found that there were no respondents who could not name any local species from South Africa. However, things changed at global level with 32 % of the participants unable to name species at global level. Endangered species are still relatively unknown, as the majority of respondents could not name any at district (84 %) or at global level (61 %). Charismatic species were known the most by respondents as 52 % mentioned them at national level and 59 % at global level. This study also assessed if there is concern for biodiversity loss. The results showed that there is concern for biodiversity with 71 % of the respondents in support for conservation and 60 % of the respondents willing to donate towards conservation. This study found that reasons for conservation related to the level of products consumed directly from the environment. Those that supported conservation for use values consumed more products from the environment than those who were in support for non-use values. Furtherly, this study found that women were more concerned about biodiversity loss than men. Highly educated respondents were more concerned and the youth was not. Furtherly, this study found that knowledge about biodiversity loss corelated with concern. For example, women had more knowledge and were more concerned about biodiversity loss. Overall, this study has shown that there is some knowledge and concern that people have about biodiversity and its loss. This can assist the relevant policy makers and researchers to know where intervention is needed to increase the knowledge that people have of biodiversity loss and which aspects of biodiversity people are most concerned about. This is so that new policies and conservation measures can include what is appealing to the local people so that support for conservation can be built and accepted by local people. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
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- Date Issued: 2022-10-14
Larval assemblages in intertidal habitats: the use of artificial and natural microhabitats
- Authors: Reddy, Seshnee
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/364992 , vital:65668
- Description: Coastal habitats, and more specifically, intertidal habitats, host a unique range of biodiversity and are key areas for many fish and invertebrate species across one or more of their life stages. This is due to the provision of microhabitats which offer an escape from harsh environmental stressors and predation as well as increased food supply, hence increasing chances of survival. Due to the growing human population however, coastal habitats are being replaced by artificial structures (jetties, seawalls, piers, breakwaters) which partially or heavily fragment the natural environment through urbanisation-related expansion processes. These coastal infrastructures also have different physical properties from the natural environment and therefore tend to support different biological assemblages and can potentially alter the existing biodiversity and its functionality. The overall aim of this project was therefore to evaluate the use of artificial and natural intertidal microhabitats by fish and invertebrate larvae along the South African, Eastern Cape coastline. As independent case studies, fieldwork was conducted at an urban (Port Alfred Marina) and rocky shore (Kenton-on-Sea) site. Within each of these study sites, two replicated sheltered subsites were selected, which represented microhabitats. Samples were collected from these replicated microhabitats from September 2019 to February 2020 using light traps which targeted phototactic larval species, as well as a portable pump, for photo-neutral/negative taxa. All samples were preserved onsite in 99% ethanol and specimens were later counted and identified in the laboratory to the lowest possible taxonomic level using a stereomicroscope. Additionally, DNA barcoding was conducted on selected larval taxa for verification of morphological identification as well as contributing to the field of larval taxonomy through development of public database records. The barcoding technique was effective in positively identifying 96% and 58% of fish and invertebrate larvae sampled, respectively (overall identification success of 86%), to either family, genus or species level. Results of microhabitat use indicate higher larval abundances associated with artificial structures as compared to natural structures, with significant differences between the selected microhabitats within the rocky shores and the marina respectively, across months. High numbers of several early stage taxa were observed within the selected microhabitats in the marina, with Pinnotheres sp. (zoea) (Family: Pinnotheridae) being the most abundant invertebrate larval taxon collected at the artificial microhabitats of jetties and vertical walls. Fish larvae of Omobranchus woodi (preflexion) and Etrumeus whiteheadi (postflexion) were the most dominant at the selected artificial microhabitats within the marina. The DNA barcoding tool used in the current study to verify morphological identification proved to be instrumental in the accuracy of the reliable data collection of the early life stages present in these habitats. These results suggest that artificial structures may provide refugia for the vulnerable very early life stages of species and, in turn, play a potential facilitative role in reproductive and population connectivity which could result in replenishment of natural populations. It is therefore possible that these urban habitats could be considered as hubs for maintenance of coastal biodiversity. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2022
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- Date Issued: 2022-10-14
Leveraging LTSP to deploy a sustainable e-infrastructure for poor communities in South Africa
- Authors: Zvidzayi, Tichaona Manyara
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365577 , vital:65761
- Description: Poverty alleviation is one of the main challenges the South African government is facing. Information and knowledge are key strategic resources for both social and economic development, and nowadays they most often rely on Information and Communication Technologies (ICTs). Poor communities have limited or no access to functioning e-infrastructure, which underpins ICT. The Siyakhula Living Lab (SLL) is a joint project between the universities of Rhodes and Fort Hare that has been running for over 15 years now. The SLL solution is currently implemented in schools in the Eastern Cape’s Dwesa-Mbhashe municipality as well as schools in Makhanda (formerly Grahamstown). Over the years, a number of blueprints for the meaningful connection of poor communities was developed. The research reported in this thesis sought to review and improve the Siyakhula Living Lab (SLL) blueprint regarding fixed computing infrastructure (as opposed to networking and applications). The review confirmed the viability of the GNU/Linux Terminal Server Project (LTSP) based computing infrastructure deployed in schools to serve the surrounding community. In 2019 LTSP was redesigned and rewritten to improve on the previous version. Amongst other improvements, LTSP19+ has a smaller memory footprint and supports a graphical way to prepare and maintain the client’s image using virtual machines. These improvements increase the potential life of ICT projects implementing the SLL solution, increasing the participation of members of the community (especially teachers) to the maintenance of the computing installations. The review recommends the switching from thin clients deployments to full ("thick") clients deployments, still booting from the network and mounting their file systems on a central server. The switch is motivated by reasons that go from cost-effectiveness to the ability to survive the sudden unavailability of the central server. From experience in the previous deployment, electrical power surge protection should be mandatory. Also, UPS to protect the file system of the central server should be configured to start the shutdown immediately on electrical power loss in order to protect the life of the UPS battery (and make it possible to use cheaper UPS that report only on network power loss). The research study contributed to one real-life computing infrastructure deployment in the Ntsika school in Makhanda and one re-deployment in the Ngwane school in the Dwesa-Mbhashe area. For about two years, the research also supported continuous maintenance for the Ntsika, Ngwane and Mpume schools. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
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- Date Issued: 2022-10-14
Linking Hop and LANA1 in the KSHV life cycle
- Authors: Ruck, Jamie-Lee
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365291 , vital:65724
- Description: Thesis embargoed. Possible release date set for early 2025. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14