Esibelekweni: Ingqokelela Yemibongo ngesiXhosa nangesiNgesi
- Authors: Busakwe, Yenzokuhle
- Date: 2023-10-13
- Subjects: Creative writing (Higher education) South Africa , Diaries Authorship , Books Reviews , South African essays (English) 21st century , Xhosa poetry 21st century
- Language: English , Xhosa
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424917 , vital:72193
- Description: My thesis is a collection of poems that is written in isiXhosa and English. It explores African spirituality, my relationship with God, heartache from romantic and platonic relationships. I make use of dual languages because some themes that I write about such as African spirituality I find words that capture their truest emotion in my Xhosa vocabulary, and I cannot find them in English. My poems use the narrative form because it allows me to tell stories through poetry without having to commit my writing to musicality or rhyming that a lyric poetry normally has. My work is shaped by writers such as Kate Beinhemer, Mangaliso Buzani, Amy Saul Zerby, Nontsizi Mgqwethio, Simphiwe Nolutshungu and Oiu Miaojin. Buzani makes use of images and few lines in his writing but still manages to capture a story with brevity. Saul-Zerby makes use of text lingo in some of her poems, and I make use of it to close a gap that I have identified with the books that I was reading that are all written in a formal and serious format. Mgqwetho’s poems explore Christianity and African Spirituality which is one of the subjects that my work is exploring too but in a manner that differs. I talk about how they have been my guidance instead of praising their powers like Nontsizi normally does in her poems. Simphiwe Nolutshungu’s poems has influenced the structure of my poems. Fairy tales written by writers like Kate helps my writing to bring to life issues that sound too dreamy to be true but have manifested as visions and memories that I cannot wipe out from my conscience. Oiu Miaojin’s novel “Last words from Montmantre” I am fascinated by how the writer detail emotions such as vulnerability and heartbreak in his storytelling. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
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Freshwater invasive alien crayfish species in South Africa: testing eDNA assessment and DNA barcoding
- Authors: Mdidimba, Nonkazimulo Dorothea
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424413 , vital:72151
- Description: The expansion of the wild populations of the two invasive alien crayfish species, i.e., Cherax quadricarinatus and Procambarus clarkii in South Africa is of high concern. Given this, innovative and improved monitoring methods are required to be explored in order to effectively detect and manage their spread. Environmental DNA (eDNA) has shown promising and reliable results to detect and monitor alien crayfish in freshwater systems even at low densities. This research study aimed to field-test the application of eDNA for detecting and monitoring invasive alien freshwater crayfish species (IAFCs) in South African freshwater systems (Chapter 2). Further, this study also aimed to confirm the true taxonomic identity of the IAFCs in South African freshwater systems by using DNA barcoding to avoid potential misidentifications with morphological identification alone (Chapter 3). Also, ectocommensal temnocephalans and leeches attached to the crayfishes were also identified with DNA barcoding. The mitochondrial COI gene fragment of the crayfishes and the ectocommensal temnocephalans and leeches was amplified, sequenced, and used for species identification. For eDNA monitoring of C. cainii, C. quadricarinatus and P. clarkii, water samples were collected from Eastern Cape, Free State and KwaZulu Natal sites that are known to house these species. The current study did not detect the eDNA of the wild populations of both C. quadricarinatus and P. clarkii. This failure was encountered despite employing several methods, such as, end-point polymerase chain reaction (PCR), quantitative PCR (qPCR) and next-generation sequencing (NGS). The eDNA assessment to detect IAFCs in the wild populations is discussed in detail, and corrective measures suggested (Chapter 2). However, only C. cainii was able to be detected by eDNA. Cherax cainii is housed/farmed in an aquaculture facility (Vaughn Bursey’s Stock Farm in Eastern Cape) with large number of individuals per pond. For this, NGS was able to detect C. cainii but the other two methods, end-point PCR and qPCR were not able to detect the species. Based on the results, refinement of eDNA monitoring methods for the South African freshwater systems is recommended. Evaluation of different DNA collection methods, preservation, DNA extraction kits and primer design to obtain effective eDNA detection is discussed as possible sources of error. Interestingly, the newly established population of P. clarkii in Mimosa Dam in Free State was infested with alien leeches, that were confirmed by DNA barcoding to be Helobdella europaea and Helobdella octatestica. Consequently, this study reports for the first time in South Africa the presence of this alien freshwater leeches. The presence of alien leeches and P. clarkii suggests a double invasion in Mimosa Dam, P. clarkii seems to continue expanding its range in the country. However, the long-established population of P. clarkii in Driehoek Farm in Mpumalanga, which has been in the country for over 30 years did not have any leech or temnocephalan infestation. This could suggest several interesting ecological phenomena, including environmental filtering over time of the co-invaders, differential source populations, and post-introduction adaptation. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
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Quinolone-Pyrazinamide Derivatives: synthesis, characterisation, in silico ADME analysis and in vitro biological evaluation against Mycobacterium tuberculosis
- Authors: Rukweza, Kudakwashe Gerald
- Date: 2023-10-13
- Subjects: Quinolone antibacterial agents , Mycobacterium tuberculosis , Antitubercular agents , Tuberculosis Chemotherapy , Drug resistance , Moxifloxacin , Isoniazid
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/390901 , vital:68596
- Description: Tuberculosis is one of the leading causes of death worldwide caused by an infectious species, Mycobacterium tuberculosis (Mtb). Some of the factors that contribute to the prevalence of this disease include the complexity of diagnosis, prolonged period of therapy, side effects associated with current TB drugs, the prevalence of resistance against the current treatment options and a high incidence of co-infection with HIV/AIDS. Thus, there is a need for new alternative drugs to provide safer and shorter treatment therapy options that are not susceptible to the development of drug resistance. In this project, we focus our attention on the quinolone pharmacophore. Quinolones are currently used as alternative options in the treatment of resistant strains of Mtb. Previous work pertaining to quinolone-isoniazid hybrid compounds showed promising in vitro activity against the H37Rv strain of Mtb and served as the inspiration to pursue this project. The journey commenced with the synthesis of quinolone-pyrazinamide hybrid compounds (Figure 3.1). These compounds were synthesised, through the attachment of the quinolone and the pyrazinamide entity through a hydrazine linker. The synthesised compounds were purified, and their structural identity confirmed using common spectroscopic techniques including 1H and 13C NMR, infra-red (IR) and mass spectrometry. In vitro biological assays were performed by testing for the activity against the H37RvMA strain of Mtb. The bioassays were performed in triplicates to ensure the accuracy of the results. Moxifloxacin and isoniazid were tested as control compounds. Finally, the resultant compounds were profiled in silico for physicochemical and ADMET properties using open access software SwissADME. All the synthesised compounds 3.8a-f showed no activity against H37RvMA. In most cases, the resulting compounds showed minimal to no activity (MICs ≥ 57.3 μM) in all three media. During the in vitro studies, the compounds showed significant precipitation in the media over time suggesting poor aqueous solubility. The SwissADME analysis of these compounds indicated poor solubility in aqueous media, which is likely linked to their molecular size and complexity. Despite poor aqueous solubility, compounds 3.8a-f showed acceptable physicochemical properties and ADME parameters. No PAINs (Pan-assay interference compounds) were observed. Minimal to no interaction with CYP enzymes were predicted. Most of the compounds were compatible with the Lipinski’s rules of five. , Thesis (MSc) -- Faculty of Science, Pharmacy, 2023
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