A native weevil and an exotic planthopper: investigating potential biological control agents for nymphaea mexicana zuccarini (nymphaeaceae) and its hybrids in South Africa
- Authors: Reid, Megan Kim
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422554 , vital:71957 , DOI 10.21504/10962/422554
- Description: Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive plant originating from southern USA and Mexico that has become problematic in South Africa, invading several water bodies around the country. Manual removal of this plant is very labour intensive and is not cost efficient or effective for long term control, while the use of herbicides is damaging to the environment and expensive. Consequently, this plant is a desirable candidate for biological control, which takes advantage of enemy release of the target weed and aims to re-establish population suppression induced by host specific natural enemies. Initiating biological control requires that several steps are followed to maximise the success of the programme, and the first few of these, including overseas surveys in the native range of the plant, have already been completed. This thesis aimed to continue biological control research for this species to take further steps at effectively managing the plant. Firstly, pre-release surveys in the invaded range are necessary to: determine what factors (including enemy release) contribute to the invasiveness of the target weed; establish a baseline of information to allow for comparison after biological control agents have been released; and identify any insect herbivores that may already be present in the country. The pre-release surveys conducted in this study revealed useful information about N. mexicana invasions in South Africa and provided evidence that enemy release is applicable to this case. However, these studies determined that a native weevil, Bagous longulus Gyllenhal (Coleoptera: Curculionidae), has expanded its host range to include the exotic N. mexicana at three sites, and may thus have potential for management of the species through augmentative releases. The invasion of N. mexicana in South Africa is further complicated by the presence of several Nymphaea hybrids originating from a complex history of horticultural trade. Although previous research has shown that several hybrid groups are present in South Africa, their parentage is not known. As biological control requires the use of host specific insects adapted to overcome the unique chemical and morphological defences utilised by plant species, hybrids are notoriously difficult to manage because they possess intermediate characters inherited from parent species to which natural enemies may not have adapted. Although biological control of hybrids is challenging, other case studies have demonstrated that it is possible to find suitable agents, but the chances of success are increased if putative parents of the hybrids are known so that they can be surveyed for natural enemies. Further molecular studies including possible parents of the Nymphaea hybrids in South Africa were thus carried out in this thesis to focus future surveying efforts. Two main hybrid groups were identified with genetic similarity to two tested putative Nymphaea parents, and this will allow further investigations of these species to improve the chances of successfully managing these hybrid groups. Some of the tested hybrids showed genetic contributions from multiple groups, some of which were unidentified, so it is necessary to prioritise the most problematic hybrids for biological control. With more insight into the genetic makeup of the Nymphaea hybrids in South Africa, investigations into the host specificity of potential biological control agents can be conducted. The ideal biological control agent should have a broad enough host range to impact and survive on both N. mexicana and its hybrids, but without a host range so broad that it would pose risk to native South African species. Host specificity trials are thus necessary to determine the suitability of potential agents. The identification of B. longulus feeding on N. mexicana during pre-release surveys motivated further investigations to determine the natural distribution, field host range, and host specificity of B. longulus in experimentally controlled conditions. Further surveys were therefore conducted at native Nymphaea sites around South Africa in addition to host specificity trials using the native Nymphaea nouchali Burm. f. (Nymphaeaceae), two populations of N. mexicana, and a cultivated hybrid. Results from the surveys and host specificity tests suggest that B. longulus is widely distributed across South Africa, is specific to Nymphaea with no observed preference between N. mexicana and the native N. nouchali, and does not perform well on Nymphaea hybrids. Hence, B. longulus is promising for use in new association biological control through augmentative releases but is not suitable for management of hybrids. In addition to the potential use of the South African B. longulus, it is necessary to conduct host specificity trials for natural enemies from the native range of N. mexicana that were prioritised in previous studies. Megamelus toddi Beamer (Hemiptera: Delphacidae) is one such species that was imported into quarantined laboratory conditions from Florida, USA. Host specificity trials were conducted using the same test plants as described for the studies on B. longulus, in addition to multigeneration trials to determine how long M. toddi could survive on non-target host plants. As with the B. longulus studies, no statistically significant differences in preference were observed between N. mexicana and N. nouchali, but M. toddi could not complete development on the test hybrid, indicating that this species is also unsuitable for the management of Nymphaea hybrids. Despite suboptimal plant health, M. toddi completed development for three generations on the native N. nouchali. This lack of host specificity deems M. toddi unsafe for release in South Africa but highlights the importance of following predefined steps to develop a biological control programme. The concluding chapter of this thesis discusses the aforementioned findings in a broader context by considering the driving forces of plant invasions in general and specifically for N. mexicana in South Africa. Case studies are also consulted to provide insight into how to proceed with managing Nymphaea hybrids in South Africa, while the factors governing host specificity and host range expansion are also discussed and considered in the context of B. longulus and M. toddi. Finally, after a consideration of the limitations of these studies, recommendations are made to continue the development of biological control for N. mexicana in South Africa. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-03-31
Innovation in ecological restoration techniques: Enhancing Portulacaria afra survivorship in degraded arid thicket
- Authors: Norman, Yondela Masande
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419276 , vital:71630
- Description: The Albany Thicket Biome has undergone extensive degradation over the past century, particularly from overstocking of livestock in the arid types of thicket. The degradation of the biome, coupled with little to no natural recovery, prompted the South African Government to implement the Subtropical Thicket Restoration Programme (STRP) in the early 2000s to rehabilitate degraded thicket using unrooted Portulacaria afra truncheons. The STRP also sought to create job opportunities, bring about social upliftment, promote biodiversity conservation and incentivise farmers and landowners in the region to promote carbon trading and farming of P. afra using carbon credits. However, the survivorship of P. afra planted using the STRP planting protocol has been less than ⁓30% because they are planted in degraded areas, where the truncheons are subjected to harsh biophysical conditions such as hard, capped soil, high soil temperatures, drought and herbivory. The aim of this study, therefore, was to improve the survivorship of P. afra planted in degraded thicket to at least 30%, using modified planting methods. In this study, four treatments were applied in 210 pondings (or micro-dams), each with P. afra planted in them (the first three treatments used rooted cuttings). The first treatment involved watering regimes where pondings were watered at varying frequencies. The second treatment involved planting companion species alongside P. afra while the third treatment involved planting P. afra underneath a nurse canopy. In the fourth treatment, unrooted P. afra truncheons were planted inside pondings. The mean survivorship of the P. afra cuttings was assessed 18 months after planting. The watering regime treatments, including the control, all yielded a survivorship of over 75%, with the significantly highest levels of survivorship being displayed in the weekly watering treatment (90.9 ± 6.8%) (p < 0.01). The companion plant treatment also produced a high mean survivorship of P. afra (94.9 ± 3.6%), significantly higher than that of the nurse plants (87.5 ± 6.3%) (p < 0.01). Among the unrooted truncheons it was found that untreated truncheons had the highest survivorship (76.2 ± 17.6%), with the lowest mean being found in truncheons that were both pruned and scarified (70.8 ± 20.8%), suggesting that this treatment, out of all of them, is the least successful under the prevailing environmental conditions in the study area. However, there was no significant differences among the unrooted truncheon treatments and their respective survivorship values to further substantiate this assertion (p = 0.26). Findings in this study also suggest that planting P. afra cuttings under a nurse plant was ideal for P. afra survivorship due to the nurse plant’s ability to ameliorate the microclimate under which the cuttings can establish and grow. Despite the soil under the nurse canopy having a significantly lower mean soil water potential (-160.9 ± 200.5 kPa), compared to the open areas (-73.4 ± 55.7 kPa) (p = 0.04), the pondings under the nurse canopy still had a lower mean soil temperature (31.4 ± 5.25°C) than the treatments in the open areas (38.5 ± 2.7°C), during the harsh midday sun. These favourable characteristics are reflected in the P. afra cuttings under a nurse canopy having a higher chlorophyll fluorescence (0.76 ± 0.06). compared to those planted in open areas (0.73 ± 0.13), suggesting that the P. afra cuttings in the former treatment had a higher photosynthetic efficiency compared to those in the latter, despite there being no statistically significant difference in chlorophyll fluorescence between the treatments (p = 0.14). Although these findings suggest that applying these modifications to planting P. afra, having achieved its objective of increasing survivorship to well over 50%, is likely to produce favourable results not only in overall survivorship, but also in fast-tracking arid thicket rehabilitation and restoration, further research on these rehabilitation techniques and their effectiveness is required. Furthermore, the downside to these treatments is that they are costly and time consuming, which puts the feasibility of large-scale programmes using these applications into question. Further investigation is required to determine ways in which the cost-effectiveness of these applications can be enhanced. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-03-31
Archontic Aporias: the mediums of memory
- Authors: Arbuckle, Julia Ruth
- Date: 2023-03-30
- Subjects: Practice research , Eastern Cape (South Africa) History , Autoethnography , Information storage and retrieval systems Memory , Archives South Africa Eastern Cape , Aporia , Memory in art , Archives in art
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408727 , vital:70520
- Description: Contextualising my research within the Eastern Cape as a descendant of 1820 settlers, I question the modalities of historical recollection by introducing memory as a viable mode of archival production alongside that of the archive. Through interrogating Eastern Cape archival institutes and employing an autoethnographic approach to my familial archives, I show that archival curation affects the gaps, schisms, and interpretations of archives as much as the ‘unreliability’ of memory. I rely on definitions from Jacques Derrida and literature from Achille Mbembe and Verne Harris, as well as reflexive methodologies, to engage the ways of remembering the past and methods of storytelling. With this undertaking, I expose the aporias within archival processes. This written component is part of broader research that encompasses theoretical study and a practice-based Fine Arts research project culminating in an exhibition that shares themes of memory, archive, trauma, and curatorial and personal heritage management. This research engages in case studies of artworks by Angela Deane and Maureen de Jager to contextualise and position the creative process. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-03-30
Enforced sojourn: Zimbabwean dispensation, special and exemption permits
- Authors: Maziyanhanga, Zvikomborero
- Date: 2023-03-30
- Subjects: Citizenship , Immigrants South Africa , Residence permit , Foreign workers, Zimbabwean South Africa , Discrimination , Emigration and immigration law South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408913 , vital:70537
- Description: This thesis investigates Zimbabwean’s immigration to South Africa. Zimbabwean’s immigration to South Africa dates back to the early 2000s. This thesis uses a combination of theories to interrogate and discuss the Zimbabwe special permits and some of the post-apartheid government’s amendments to the South African Citizenship Act and other immigration policies. Some of the theories that theoretically underpin this research project’s methodology include Marxism, Pan-Africanism, Liberalism and culture-based theories. This thesis interrogates the discursive strategies these permits draw on to frame and understand Zimbabwean immigrants in South Africa. This study has found that these permits use similar operating logic as the White South African governments used the migrant labour system to exploit Blacks from all of Southern Africa in the 20th century. For instance, the migrant labour system used during apartheid made all Blacks in South Africa “guest workers” who could be deported at the government’s whim. The apartheid government used racist pass laws to regulate the movement of Black people in South Africa, whereas the post-apartheid government uses Zimbabwean special permits to regulate the movement of Zimbabweans in South Africa. The pass laws were fundamentally racist, and their ultimate objective was to reinforce the idea of White citizenship, whereas the Zimbabwe special permits are not racist. Their colonial similarity, however, lies in how they make Zimbabwean migrants perpetual migrants in South Africa and the various ways in which they cast Zimbabweans as not deserving of South African citizenship. These special permits force Zimbabwe migrants to become “guest workers” who build the post-apartheid economy and then return home when they are no longer “useful” to the economy. This thesis concludes that the post-apartheid Zimbabwe special permits achieve analogous objectives. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2023
- Full Text:
- Date Issued: 2023-03-30
Experiences of men vlogging about substance use disorder recovery on YouTube
- Authors: Chele, Palesa Shené
- Date: 2023-03-30
- Subjects: Substance abuse Treatment , Sobriety , Alcoholics Anonymous , Narcotics Anonymous , Recovery , Remission , Video blogs
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408829 , vital:70529
- Description: The journey of substance use recovery is an inherently dynamic and on-going process. It is advanced through secure social support systems. Furthermore, requiring the explicit practice of self-advancement and self-efficacy. However, in South Africa, despite the continued upsurge of substance abuse, there remains a substantial gap between the high demand for treatment and the limited capacity to provide state-funded treatment. In addition, various psychosocial and socio-economic factors further impede access to treatment or recovery support. Thus, within communities facing SUD treatment barriers the exploration of individual lived experiences may deepen understandings of how men experience the journey of substance use recovery. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-30
Pathi’s sister is still troubling
- Authors: Naidoo, Savani
- Date: 2023-03-30
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century , Short stories, South African (English) 21st century , Diaries -- Authorship , Books Reviews
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408942 , vital:70539
- Description: My thesis is a collection of micro fiction, flash fiction, fairy tales, vignettes and short stories which explore the tension of being both an insider and an outsider. I have access to different cultures without belonging to any of them: as a child, my family moved from a South African Indian community to a formerly whites-only suburb; as an adult I have lived in South Korea, the United Arab Emirates and Sudan. My prose draws on my life experiences, family legends, neighbourhood gossip, news reports and historical events to question norms and ideas that I may have taken for granted had I been fully inside a single culture. In my thesis I frequently spell words phonetically to mimic how I hear or remember them. I also borrow words from languages I don’t speak. I want the languages I use and mix to corrupt each other, as Raymond Federman put it, in order to better express the voices and contexts of the communities I draw inspiration from. Kuzhali Manickavel’s Things We Found During the Autopsy showed me that culturally rich imagery can be used without interrupting narrative flow with explanations. I am also influenced by the poetic sense of rhythm and melody of Lydia Davis’s minimalist prose, and by Sandra Cisneros’s The House on Mango Street, where each concise short story stands alone but together creates a broad understanding of people and place. Anthologies such as PP/FF, edited by Peter Conners, and My Mother She Killed Me, My Father He Ate Me, edited by Kate Bernheimer, have inspired me to be bold in finding the form that best allows each narrative to be told. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
- Full Text:
- Date Issued: 2023-03-30
Saul Msane: friend or foe of the people? The life of the late nineteenth to early twentieth centuries South African politician and journalist
- Authors: Mokoatsi, Thapelo
- Date: 2023-03-30
- Subjects: Saul Msane , Elite (Social sciences) , African National Congress , Politicians South Africa Biography , Political dispute , Abantu-Batho , Enemy of the people
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/409799 , vital:70631 , DOI 10.21504/10962/409802
- Description: Saul Msane was a prominent founding member of the ANC and an active journalist and editor of the ANC newspaper Abantu-Batho. His career generated controversy. Towards the end of his life, he had a feud with his colleagues in the African National Congress (henceforth Congress) that led to him being labelled isitha sabantu, “the enemy of the people” for his refusal to support the Shilling strike of 1918, an accusation which was retracted a year after his death in 1919. The label of isitha sabantu levelled against Msane, had the effect of ending his political prominence in the Transvaal, forcing him to relocate to kwaNongoma where he died shortly thereafter. Msane’s years in the Congress amounted to about seven years, between 1912, the founding of the Congress, and the demise of his career in 1919. Msane’s seven years in Congress were characterised by controversies, clashes, and conflicts owing to his perceived elitism. In Congress historiography Msane is an obscure and elusive figure, he lives here and there in a footnote, as a supporting statement or a mentioned in mere passing. His marginalisation reveals some of the gaps within the history of Congress and invites us to write about those who did not emerge from the history of Congress necessarily as heroes. This thesis sets out to write a biography of Msane and document his political career beyond that one moment in which he came to be “isitha sabantu”. While Msane’s Congress career was comparably short and filled with tensions, an archive of his life exists. This study is an exploration of that archive to reconstruct the biography of a once prominent leader who dies in political exile from the Congress movement. This thesis sets out to do two key things in relation to reconstructing Msane’s life: Firstly, it reconstructs the longer biography of Msane’s political life by drawing on the existing archives, and thus filling in the South African historical record in that regard. Secondly, at the broader conceptual and historiographical level, it argues that the controversies surrounding Msane’s persona and character illustrate that conceptions of elitism and the nature of being ‘elite’ were key to the politics of Congress at the time. , U-Saul Msane wayengomunye wabasunguli beqembu lika-African National Congress (uKhongolose) futhi eyIntatheli nomhleli wephephandaba i-Abantu-Batho. Umsebenzi ayewenza waba nezingqinamba eziningi ngokwezepolitiki. Ngasekugcineni kwempilo yakhe waba nokungazwani nabaholi ayesebenza nabo kuKhongolose okwadala ukuba abizwe ngesitha sabantu ngenxa yokuba engavumelananga nesiteleka sango-1918 lapho abasebenzi babelwela ukukhushulelwa amaholo. Leligama lokubizwa ngesitha sabantu lahoxiswa ngo 1919 sekudlule unyaka engasekho emhlabeni. Lokubizwa ngesitha sabantu kwalilimaza igama lakhe kwezepolitiki e-Transvaal waze wathutha wayohlala kwaNongoma nokuyilapho ashonela khona. Iminyaka uMsane ayisebenzele uKhongolose yaba isikhombisa, kusukela ekusungulweni kwayo ngo 1912 kuze kufike ekulimaleni komsebenzi wakhe wezepolitiki ngo 1919. Kuleminyaka eyisikhombisa umsebenzi wakhe kuKhongolose wawubhekene nokugxekwa okukhulu nokubukeka njengomuntu onokuzenza ngcono kunabanye abantu. Emlandweni kaKhongolose uMsane akavezwa ngendlela emfanele, kukhulunywa ngaye kudlulwa nje. Lokunganakwa kukaMsane emlandweni kaKhongolose kusiphoqa ukuba sibhale ngabaholi abangaqakanjiswa. Lolucwaningo luveza umlando kaMsane ngokujulile ngaphezu kwangalesikhathi abizwa khona ngesitha sabantu. Noma umsebenzi kaMsane kuKhongolose wabamfushane kunabanye futhi ugcwele izinto kodwa noko ingobo yawo ikhona. Lolucwaningo lucubungula lengobo ukuhlaziya nokubhala kabusha umlando wengqalabutho eyagcina ishonela ngaphandle kombutho kaKhongolose. Loluphando lifisa ukwenza izinto ezimbili: Okokuqala, ibhala kabusha umlando omude wezepolitiki kaMsane kusetshenziswa ulwazi olukhona. Loku kuzosiza ukunothisa umlando wezepolitiki wezwe laseNingizimu Afrika. Okwesibili, ezingeni lobunzululwazi, lolucwaningo luveza ukuthi izinkinga uMsane ahlangabezana nazo zazisukele endleleni okwakubukwa ngayo indaba yokucwasana ngazinga empilo abantu, kwakuyinto ejulile kuKhongolose ukubukeka kwabanye sengathi bazenza ngcono. , Thesis (PhD) -- Faculty of Humanities, History, 2023
- Full Text:
- Date Issued: 2023-03-30
A Pedagogy of Love: reflections on 25 years of informal vocational education and training practices in the commercial fishing industry in South Africa
- Authors: Ferguson, Robin Anne
- Date: 2023-03-29
- Subjects: Vocational education South Africa , Fisheries Vocational guidance South Africa , Practice theory , Transformative learning , Technical and Vocational Education and Training
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366189 , vital:65841 , DOI https://doi.org/10.21504/10962/366189
- Description: This thesis is a reflection of informal vocational education and training (IVET) practices conducted by the Researcher in the commercial fishing industry between 1995-2021. Fourteen interventions took place during this time which involved several hundred sea-going employees who are disadvantaged by low levels of literacies and low/no Internet Computer Technology connectivity. The Production Programme was chosen as the focus of study and draws upon the influence of the other thirteen programmes. The purpose of the Production Programme was to teach technical fish processing skills to the production management teams and factory hands who work in the factories on board the vessels. The programme ran for five years and evolved through three distinct generations. At the heart of this work lies the question: ‘What made these programmes successful?’ This is an intra-programmatic study and seeks to identify the pedagogical practices which promoted or confounded the efficacy of the Production Programme; and based upon this understanding how such programmes could be improved, transferred, and taken to scale. These questions are both descriptive and explorative in nature. IVET is regarded as training which takes place outside of the formal South African National Qualifications Framework. This work is relevant because approximately 80% of sea-going staff neither finish school, nor get the opportunity of Post School Education and Training by going to a university, a technical institution, or a community college. This statistic is reflected in the general population (Department of Higher Education and Training [DHET], 2022). There is a fine line between being employed and unemployed for people working at this level in the formal economy which makes this project relevant to youth or persons who are ‘not in employment, education or training’ too. This means that for most South African adults IVET presents a significant opportunity for post-school education. Therefore, it is important to answer the questions raised above to rapidly improve inclusion of the majority of South Africans into meaningful education which improves livelihoods. The Theory of Practice Architectures (TPA), from the collection of social-material practice theories, is the conceptual framework for this thesis. The smallest unit of analysis of TPA are practices which may be ‘sayings/thinkings’, ‘doings’, or ‘relatings’. These practices bundle together into practice arrangements and form practice architectures. The reason that TPA was chosen was that practices were the only data available as we (learners, managers, facilitators, and me) knew what we had said/thought or done, and we were aware of the relationships between us over the years as the fourteen interventions played out. Under conventional research circumstances data would be collected in real time, however in this project, most of the data is historical. In addition to the fundamental building blocks of TPA, the theory is embedded in a Theory of Education. There have also been contemporary enhancements to the TPA which were significant to this study, for example, the Ecologies of Practices, a Trellis of Practices which Support Professional Learning, Middle Leadership, Travelling Practices, and moves towards transformative or transgressive education using the TPA in IVET. This is empirical, qualitative research and an ethnographic case study was chosen as the research design which is a methodology particularly suited to answering both descriptive and explorative questions. Nine methods for data collection were used, namely an historical reflective narrative; two focused-group interviews; three individual interviews; four Whatsapp videos; one WhatsApp voice note; two mobisodes; ten questionnaires; 29 documents; and 16 photographs. Because this data was collected under Covid-19 pandemic conditions, two conceptions were employed to guide the generation of data under these uncertain and constrained conditions. These were firstly, the ‘methodology of chance’ which allowed for a ‘methodological agility’; and secondly, the idea of ‘information power’ which is helpful in deciding on how much data is enough. In order to be explicit concerning a key research activity, the approach and method used to review the literature is explicated. Key practices were identified in the data set and described; and then the data was analysed using heuristics provided by TPA theorists. Seven Tables of Invention were used to synthesise the data arising from these practices. An eighth Table of Invention was used to synthesise all the practices and practice arrangements characterised; and to indicate how these evolved over time and space. The data description and analysis is supported by eight Analytic Memos, a comprehensive Data Code Table and a hyperlink to a data repository which provides access to oral and video material. The findings distinguished five key practices and practice arrangements which were: Practices of the Creation of Courseware; Practices of Teaching and Learning; Practices of Assessment; Practices of Love; Practices of Management. The thesis title is reflective of the impact which love has upon the pedagogical process of IVET. Based upon the analysis and synthesis of the corpus of data, practices which either promoted or confounded the Production Programme became visible; it is these insights which inform future improvements to similar programmes. Emanating from these findings, two overarching practice architectures (PA) were identified which restrained the Production Programme in the same manner that the banks of a river restrain a river, and yet simultaneously, are changed by the river over time. These are the PA of Methodology and Methods and the PA of Maturing Ecologies of Practices. The inferences drawn from the data were achieved through the use of deductive, inductive, and abductive reasoning. My claim to new knowledge is a lamination of a practical contribution on one side of the coin, and a theoretical contribution on the other side of the coin. The PA of Methodology and Methods provides a practical mechanism to create, deliver and assess IVET. This is done by explicating the three practice architectures which constitute the overarching PA of Methodology and Methods which are, the PA of Informality; the PA of Range, and the PA of Relationality. An IVET programme constitutes Ecologies of Practices. The theoretical conception of the overarching PA of Maturing Ecologies of Practices provides a conceptual tool which enables the transferring and scaling of IVET programmes. It does this by providing theoretical indicators to establish the ‘state’ of an IVET programme as it matures over time from a pioneer state to a settler state. An IVET educator can then work towards creating a PA which is conducive for a mature ecologies of practices to form; and the programme can then be transferred and/or taken to scale, if this is desirable in the particular context. The power of my claim to new knowledge does not lie on one side or the other of the coin, but in the lamination of the practical and theoretical contributions put to use in the service of IVET. This thesis concludes with a number of theoretical and practical recommendations which are loosely grouped according to ‘sayings/thinkings’, ‘doings’ and ‘relatings’ in deference to the value of TPA to this thesis. An urgency is conveyed in these recommendations as there is an immediate need to improve the livelihoods of ordinary South Africans. One of the ways of doing this is through informal ‘education for living well’ which contributes to a ‘world worth living in’. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
Coastal movements and estuarine use of sub-adult and adult leervis, lichia amia: results from long-term acoustic tracking
- Authors: Mxo, Rebecca Vuyolwethu
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422314 , vital:71930
- Description: Information on fish movement is important not only for understanding a species’ ecological importance, but also for developing appropriate conservation and management policies that are critical for food security and biodiversity preservation. This information is particularly important for species that occupy different habitats at different life history stages, and display predictable movement patterns, such as an annual spawning migration. Leervis Lichia amia is an estuary-dependent fishery species of high ecological and recreational importance in South Africa. There has been a steady decline in catch-per-unit-effort in the marine recreational fishery for this species over the past 20 years, and the most recent stock assessment classified the adult stock as collapsed. This study investigates L. amia multi-year coastal migrations and estuarine habitat use of sub-adult and adult fish tagged with long-life acoustic transmitters Seventy-eight L. amia (two juveniles, fifty-four subadults, and twenty-one adults) were tagged throughout their South African distribution and monitored between 2011 and 2020 producing a decade long dataset. Results show that regardless of the tagging region, clear migration patterns were observed, demonstrating that both sub-adult and adult L. amia migrate annually to KZN in the austral winter and predictably return to the WC and EC waters in the summer. The likelihood of partial migration was also identified, with the coexistence of migratory and resident behaviors within a single L. amia population. In addition, Overwintering behaviour was also observed with L. amia adults that remained resident throughout the year, foregoing the annual migration, phenomenon known as skipped spawning, and homing behaviour, where L. amia, particularly those tagged in the EC and WC, were recorded returning to previously occupied tagging locations and surrounding areas. The importance of estuaries to sub-adult and adult fish was also assessed and identified the importance of estuaries not only to subadults but also to adults. Estuary visits were strongly influenced by the environment which the fish was tagged in, temporal and seasonal changes, and life-history stages. The predictability of their migrations (almost to the day), the varied migratory behaviour (overwintering), returning to sites of familiarity post-migration, and long-term dependency on estuaries even as sub-adults and adults, provide motivation for increased protection of this species, including extending the network of estuarine protected areas in the country, and a closed fishing season, particularly during the annual winter migration. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-03-29
Expression, partial characterisation and utilization of a GH11 xylanase (Xyn2A) from Trichoderma viride as an additive in monogastric animal feeds
- Authors: Mzimkulu-Ncoyi, Nosabatha Happyness
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422409 , vital:71940
- Description: Endo-xylanases (shortly called xylanases) are a group of glycoside hydrolase enzymes that target β-D-1,4-linkages in the xylan backbone, leading to the production of xylooligosaccharides (XOS) of varying degree of polymerization (DP). Xylan is an indigestible non-starch polysaccharide present in monogastric animal feeds which in high amounts leads to increased digesta viscosity, slow movement of digesta in the intestines, malabsorption of nutrients among other challenges. The aim of this study was to investigate the effect of xylanase 2A (Xyn2A) from Trichoderma viride on broiler chicken feeds, particularly the hydrolysis of the xylan content, reduction of feed viscosity and the effect of produced XOS on eliciting the growth of gut associated probiotic bacteria. Xyn2AE was successfully induced with 0.8 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) and produced in Escherichia coli BL21 (DE3) and Xyn2AC was expressed in tobacco mosaic plants. For the purification of Xyn2AE, an immobilized metal affinity chromatography (IMAC) column and diafiltration using a 3kDa cut-off Amicon filter membranes were used. Xyn2AE and Xyn2AC showed a xylanase active band at a relative weight of 21 kDa. Both enzymes showed high specificity towards soluble wheat arabinoxylan (WAX), with specific activities of 7.61 U/mg for Xyn2AE and 536.5 U/mg for Xyn2AC. Xyn2A kinetic parameters (Vmax and Km) were determined by Michaelis-Menten plots on soluble and insoluble WAX. The Vmax and Km values of Xyn2AC were 1003.01 U/mg and 9.25 mg/mL, 302.89 U/mg and 13.54 mg/mL, respectively. The Vmax and Km values of Xyn2AE for soluble and insoluble WAX were 20.45 U/mg and 12.95 mg/mL, and 8.31 U/mg and 13.15 mg/mL. Xyn2A enzymes displayed optimum activity at pH and temperature parameters of 5.0 and 50°C, respectively, and stability in temperatures ranging between 50 and 80°C and pH 4.0-9.0. Broiler chicken feeds were hydrolysed using Xyn2AE over a 24 h period and analysed using the dinitrosalicylic (DNS) assay, thin layer chromatography (TLC), viscometry and visualized using scanning electron microscope (SEM). The results showed a release of release of XOS xylotriose, xylopentose and xylohexose; enzyme’s ability to decrease the viscosity of the feeds and punched holes of feed surface, which was indicative of xylanase action. XOS produced during hydrolysis was used to study prebiotic effect on selected few bacteria and released short chain fatty acids (SCFAs) were measured. Additionally, SCFAs formation was detected in the presence of XOS as a carbon source for S. thermophilus and L. bulgaricus, whereas B. subtilis formed fewer organic acids in the presence of XOS. The results obtained from this study demonstrated that the supplementation of Xyn2A on broiler feeds has ii a positive effect in decreasing feed viscosity. Furthermore, the results of this investigation will assist the South African poultry farming sector to increase profitability in poultry farming and gain stability in the global trade as far as poultry feed is concerned. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-03-29
Factors influencing the number of non-timber forest product species used at the individual, household and village levels in Vhembe, Limpopo Province, South Africa
- Authors: Mulaudzi, Takalani Rachel
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422481 , vital:71946
- Description: Non-Timber Forest Products (NTFPs) are wild biological resources obtained from natural landscapes, agricultural systems, and rural and urban regions for a variety of uses. NTFPs contribute significantly to livelihoods and living standards by offering a variety of socioeconomic benefits such as food, health, income generation, and safety nets. These multiple benefits are provided by a wide diversity of plant, animal and fungal species in different settings. However, the precise number of NTFP species used depends on the scale of assessment, namely use by individuals, by households and by villages. Consequently, it is difficult to compare numbers of species used between studies because of the differing scales. As a result, the objective of this study was to determine the number of NTFP species used at three different scales and how each is correlated with appropriate scale-dependent contextual variables. This objective was met by sampling individuals and whole households in five villages in the Vhembe District in Limpopo Province, South Africa. Twenty households were randomly selected in each village, providing a total sample of 100 households and 179 individuals in those households. In each household, every adult member was interviewed individually about the NTFPs that they used or knew. The major questions covered the NTFP species used, the respondents' socioeconomic level, the NTFP species used previously, and if the number of NTFP species are changing in the landscape. Data were reported per individual as well as per household and per village. The household level was derived by adding the responses of all the adults in each household but excluding duplicates. The same approach was used at the village scale, namely, the data across the 20 households were pooled, and duplicates were omitted. Patterns of NTFP use were examined by type of NTFP, and analysis using standard statistical tests, along with a Principal Components Analysis and a multivariate Detrended Correspondence Analysis of the NTFP species composition across villages. A total of 275 species of NTFPs were mentioned across the entire sample, including 81 species of firewood, 48 species of edible insects, 43 species of wild vegetables, 40 species of edible fruits, 38 species of wood utensils, 28 species of medicinal plants, 23 species of thatch grass, 19 species of poles, 19 species of wood for carvings, nine species of reeds, eight species of mushroom, and eight species of fodder. Of these species, some species had more than one use. Approximately 90% of the species used by the respondents were native species. Wild vegetables (e.g., Corchorus olitorius, Amaranthus capensis, Bidens pilosa), firewood (e.g., Colophospermum mopane, Parinari curatellifolia, Combretum hereroense), wild fruit (e.g., Landolphia kirkii, Vangueria infausta), and edible insects (e.g., Imbrasia belina, Macrotermes michaelseni, Encosternum delegorguei) were the most often used NTFPs by communities in the Vhembe area. Most of the households relied on NTFPs for subsistence. At the scale of an individual, the mean number of NTFP species used was 26.8±12.6 across the five villages. When considering a household, the mean number was 36.1±10.7 species. When aggregated across the 20 households per village, the mean number per village was 105.2±34.1 species. The species accumulation curve showed that 20 households per village were reasonably representative for four of the five villages. The results from the principal component analysis (PCA) and correlation analysis revealed that age, education, and employment status were significantly associated with the number of species used by individuals, whereas gender showed no clear correlation. At the household scale, household size was positively related with the number of species used, but income level and income source were not. At the village scale, attributes such as proximity to a town, settlement type, vegetation type, and distance to a nearby savanna all had some influence on the number of NTFP species listed. Most of the respondents felt that the number of species used had increased over the last 10–15 years, although some stated the opposite. Increases were attributed by traditional councils bans, the establishment of protected areas, and restoration. Activities eroding the number of NTFP species were identified as clear felling for farming, climate change, and over-harvesting. This study suggests that communities must be made more aware of the overharvesting of NTFP species in the savanna to avoid biodiversity loss. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-03-29
Making the personal political: understanding the impacts of participation in an anti-rape protest for women who have experienced sexual violence
- Authors: Barker, Kim Elise
- Date: 2023-03-29
- Subjects: Sexual assault South Africa , Silent protest , Under-reporting , Sexual abuse victims Attiudes , Narrative inquiry (Research method) , Rape Psychological aspects
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422590 , vital:71960 , DOI 10.21504/10962/422590
- Description: South Africa is recognised as a country with unusually high levels of rape and sexual violence. The majority of those who experience sexual violence do not acknowledge, disclose or report it, and do not access support. Many factors have been identified which can inhibit acknowledgement and disclosure. While silence is to be honoured as a chosen response, unwanted silencing is of concern. The annual Silent Protest at Rhodes University is a day-long anti-rape protest which draws attention to the attitudes and practices which silence victim-survivors, and enacts solidarity with victim-survivors of sexual violence. I conducted a three year “critically engaged, activist ethnography” with the community of Silent Protestors and organisers. My focus was on the stories that victim-survivors told about the impacts of participating in the protest. Changes in the research context allowed for a participatory action research cycle to be incorporated into the methodology. This offered an opportunity to implement and evaluate some changes suggested by my research contributors. My contributor’s narratives highlighted the ways in which as a society we position those who have been subjected to sexual violence in ways that are limited and limiting and which diminish victim-survivors’ sense of agency and value. This malignant positioning restricts the choices available to victim-survivors. The anticipation of being positioned in negative ways can inhibit victim-survivors from disclosing a violation and accessing care and justice. Participation in the Silent Protest seems to stand against some of the factors which inhibit acknowledgement and disclosure. Through their participation many women took up opportunities to share their story with at least one other person and to receive and offer care. Most described participation as having been beneficial and having helped them move towards living well again. The ways in which the Silent Protest positioned victim-survivors and the choices they were offered in relation to that positioning seemed to open up opportunities for thinking, feeling and acting in ways that they preferred. This suggests that interventions which mobilise both political resistance and mutual care hold promise for developing more accessible and effective services to those affected by sexual violence. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-29
Microbial and extracellular polymeric substance dynamics in arid–zone temporary pan ecosystems
- Authors: Bute, Tafara Frank
- Date: 2023-03-29
- Subjects: Extracellular polymeric substances , Biofilms , Vernal pools , Microbiomes , Sediment–water interface
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422258 , vital:71925
- Description: Microbial communities of bacteria, viruses, algae, protozoans and fungi participate profoundly in aquatic systems, particularly in mediating processes such as primary production, decomposition, and biogeochemical cycles. In addition, microbiomes produce extracellular polymeric substances (EPS) which encompass a hydrated exopolymer mainly constituted of carbohydrates and proteins. The exopolymer aid proliferation and persistence of biofilms on their resident surfaces. There is however paucity of data on functional diversity of microbiomes in arid zone temporary wetlands with previous research having mainly focused on permanent systems in the northern hemisphere. In the face of ongoing climatic changes and anthropogenic threats to wetlands, it is imperative to assess the health status of aquatic systems in relation to microbial productivity dynamics. In this thesis, colorimetric methods and sequence–based metagenomics were conducted to quantify microbial EPS production and bacterial metagenome functions, respectively. This study was conducted in Khakhea–Bray region (North–West, South Africa) in June 2021 and January 2022 with a focus on evaluating microbial patterns of distribution between seasons (i.e., Dry and Wet) and varying depth i.e., deepest zones (Deep), intermediate depth (Mid) and shallowest regions (Edge). Additionally, potential relationships between EPS and either water content or organic matter content (OM content) were evaluated. In this study it was hypothesized that wet phases and deeper zones will have high EPS production and support more functions in comparison to shallowest regions and dry phases. Carbohydrates and proteins were quantified using the Dubois method and modified Lowry procedure, respectively. Carbohydrates generally occurred in higher proportions than proteins, suggesting that EPS found in these systems was largely diatom produced. The wet phases (wet season and inundation periods) supported more EPS production compared to the dry phases. The results of principal components analysis (PCA) and Spearman’s correlations suggested that EPS was highly correlated with sediment water content among other assessed variables. No significant associations were established between EPS and organic matter content. Spatial distribution of EPS demonstrated similar patterns between the deepest (Deep) and the intermediate depth zones (Mid) however the shallow regions (Edge) had significantly lower concentrations. Bacterial characterization was established by amplification of the 16S rRNA gene using illumina–sequencing protocol. Enzyme functions associated with biogeochemical pathways were predicted in PICRUSt2 bioinformatics pipeline. A total of 15 042 Unique Amplicon Sequence Variants (ASVs) were observed to be affiliated to 51 bacterial phyla and 1 127 genera. All top genera had commonality in heat tolerance. Firmicutes, dominated at phyla level with 59 % (mean ± sd, 19 ± 13 %) relative abundance followed by Actinobacteria and Proteobacteria both at 34 % (18 ± 7 %) and (18 ± 6 %), respectively. Microbial diversity matrices highlighted significant differences in beta diversity more than alpha diversity. Bacterial microbiomes were more distinct between seasons compared to within season, suggesting that functions were seasonally driven. These findings were supported by highest rates of denitrification, carbohydrate degradation and EPS production by core microbiomes in the wet season as compared to low rates of nitrogen mineralisation, carbon fixation and nitrification in the dry season. The present findings represent a first attempt in evaluating sequence–based metagenomics in semi–arid southern African temporary pan ecosystem. Both microbial EPS and bacterial functional potential were highly driven by water availability, with highest rates mainly associated with maximum inundation compared to dry states of pans. It can therefore be suggested that extended dry periods are threatening to microbially mediated processes in temporary wetlands, with implications to loss of biodiversity due to desiccation resulting in poor nutrient cycling. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-03-29
The link between behavioural plasticity and aerobic scope phenotypes in predicting the survival of Chrysoblephus laticeps under climate variability
- Authors: Bailey, Lauren Ashleigh
- Date: 2023-03-29
- Subjects: Chrysoblephus laticeps , Phenotypic plasticity , Fishes Climatic factors , Fishes Physiology , Fishes Behavior , Respirometry , Anthropocene , Thermal tolerance (Physiology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422606 , vital:71961 , DOI 10.21504/10962/422606
- Description: Thermal variability in the marine environment is likely to have a considerable effect on fishes as it impacts physiological performance and vital (i.e metabolism, foraging and swimming style) and non-vital (i.e. reproductive fitness) energetic processes. When fish are subjected to thermal stress, they may primarily respond by changing their behaviour. Species that have broad phenotypic behavioural plasticity (i.e. defined as the ability to adjust behavioural activity in presiding environmental conditions in order to remain within their optimal thermal range) may have a competitive advantage. Fish behavioural plasticity may take many forms. Some species may seek out thermal refugia by changing their phenology or distribution, while others alter the timing of their seasonal and spawning migrations in response to a changing environment. Although fishes can use behavioural changes to cope with climate change impacts, there does appear to be variability in the behavioural responses within species. However, if alterations in behaviour are insufficient to ensure that the individual remains within their optimal thermal range, physiological acclimation (i.e. defined as the process in which an organism adjusts to prevailing conditions by broadening their thermal performance curve so that their performance is maximized in the new thermal environment) may be required. Therefore, there is a critical link between the behaviour and thermal physiology of fishes, particularly in a world where they are facing increasing thermal stress. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-03-29
Participation dynamics in the management of protected areas: the case of Dwesa-Cwebe Nature Reserve and its adjacent communities, Eastern Cape Province, South Africa
- Authors: Nyamahono, James Donald https://orcid.org/0000-0002-1391-9126
- Date: 2023-03
- Subjects: Protected areas , Natural resources conservation areas -- South Africa , National protected areas systems
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27358 , vital:66947
- Description: In many parts of the developing world, participation in the management of ‘protected areas’ is among the most tangible indices of how the rural population encounters formal conservation policies, strategies and ideologies. However, some scholars have argued that the sharing of the burdens and benefits of participation is devoid of equity. While some analysts have emphasised the imperative of multi-stakeholder participation in nature conservation, citing this as a crucial socio-ecological investment, others have highlighted the inherent contradictions in the process, describing it as an avenue for manipulation, tokenism and exploitation. This study is located in this debate and focuses on narratives around the participation of different stakeholders in the management of Dwesa-Cwebe Nature Reserve and its adjacent communities in the rural Wild-Coast, Eastern Cape, South Africa. The researcher notes that research on the degrees and participation dynamics among various role players involved in the management of protected areas in South Africa, Dwesa-Cwebe Nature Reserve in particular is limited. Against this background, this study contributes to ongoing discussions on protected area management in South Africa but seeks to expand this discussion by interrogating the nature and degrees of participation within the Dwesa-Cwebe Nature Reserve - to deepen intellectual understanding on the significant role played by protected areas in engendering participatory democracy, equity, justice as well as meeting the needs of marginalised communities. Primary data for the thesis were collected using in-depth and key-informant interviews with officials from government institutions and parastatals, politicians and traditional authority figures. Focus group discussions were held with ‘youth’ participants as well as ‘elders’ in the Reserve’s adjacent communities. An analysis of policy and other government documents sought to outline the institutional attributes of protected areas management in South Africa and the underpinning ideas. A thematic analysis of the corpus of empirical information helped to show how these institutional attributes inhere in Dwesa-Cwebe Nature Reserve as well as the epistemic challenge these attributes pose vis-à-vis indigenous ecological ideas and practices in the adjacent ‘indigenous’ communities. The study revealed that participation is perceived differently by various stakeholders due to multiple, mutually contradictory impulses. While institutional stakeholders attached great importance to the structural role of institutional frameworks, hence the vigorous reliance on formal conservation strategies, narratives from community members drew attention to ‘equity deficits’. The study also found that while the selected Reserve may have fostered cooperation between government and the adjacent communities, conflict and distrust ran deep between these stakeholders. From these and other findings, the study concluded that ecological participation in the study area was characterised by clusters of stakeholders who regard one another as ‘epistemic outsiders’ and related to one another as such, with practical consequences – especially for the long-term sustainability of the Reserve. In the main, the thesis rests on the argument that in the face of epistemic differences, dominance and marginalisation could become a defining feature of protected area management that cannot be readily resolved through the mere process of participation. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2023
- Full Text:
- Date Issued: 2023-03
Evaluating the establishment of a new water hyacinth biological control agent in South Africa
- Authors: Miller, Benjamin E , Coetzee, Julie A , Hill, Martin P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451399 , vital:75046 , http://dx.doi.org/10.17159/2254-8854/2023/a15613
- Description: Megamelus scutellaris Berg (Hemiptera: Delphacidae) is the most recent of nine biological control agents developed to manage invasive water hyacinth, Pontederia (= Eichhornia) crassipes Mart.(Pontederiaceae), in South Africa. More than a million M. scutellaris have been mass-reared and released since the first introduction of the agent into South Africa in 2013, successfully establishing overwintering populations at 32 sites in seven of the nine provinces. Establishment has also been recorded at seven of these sites through natural dispersal from sites where they had established. Inundative releases, where large numbers of M. scutellaris are released regularly, have resulted in excellent establishment, and caused a significant reduction in water hyacinth cover in areas where, historically, biological control seemed unlikely due to excessive eutrophication. Although M. scutellaris has established well throughout South Africa through classical biological control methods, this study also showed that inundative releases of biological control agents over multiple seasons results in the most effective control of the weed, especially at cool temperate and eutrophic sites.
- Full Text:
- Date Issued: 2023
Impact of sustainable tax revenue and expenditure on the achievement of sustainable development goals in some selected African countries
- Authors: Kola, Benson Ajeigbe
- Date: 2023
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/9234 , vital:73024
- Description: Abstract The study examined the impact of Sustainable Tax Revenue and Expenditure on the achievement of Sustainable Development Goals in African countries using secondary data. The dataset was extracted from the World Development Indicators database. The large gap between developed and developing countries when comparing the probability of them achieving the SDGs was the main motivation behind this study. Data retrieved from 45 countries comprised of both African and developed countries for the period 2010–2020 was analyzed using the Generalized Method of Moments technique. The results revealed that the coefficients of grants received, various forms of taxes, and other revenue have a positive effect on economic growth but a negative effect on poverty and unemployment for African and developed countries. This finding suggests that improvements in tax revenue generation, grants and other revenue accumulation across different sources boost economic performance and the welfare of individuals in the analyzed countries. The outcome is an indication that accumulating more grants from different sources will help to achieve sustainable development, improve financial stability, contributes to the economic growth and development in these countries. This study can guide policymakers, governments, international institutions, revenue bodies such as SARS and other stakeholders in their various planning and other decision-making endeavors. Governments and other policymakers must ensure the efficient generation and sustainable utilization of revenue generated from taxes and other revenues to spur the growth and development of their countries. They should have Growth-Sustainability-Oriented Fiscal Adjustment Programs and Sustainable Government Expenditure that can help push and redirect governments to achieve the SDGs in Africa.
- Full Text:
- Date Issued: 2023
Mosquito community composition in Central District, Botswana: insights from a malaria endemic to non-endemic gradient
- Authors: Buxton, M , Nyamukondiwa, C , Kesamang, M , Wasserman, Ryan J
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452402 , vital:75126 , http://dx.doi.org/10.17159/2254-8854/2022/a13584
- Description: Spatial distribution of vector mosquitoes plays a critical role in the dynamics of associated diseases' spread across diverse landscapes. In Botswana, six Districts are implicated as malaria endemic zones, one of which is the Central District comprising both malaria endemic and non-endemic sub-districts. Despite being the biggest in the country, mosquito diversity in this District is under-explored, more so in the malaria non-endemic sub-districts. Here, we thus sampled mosquito adults and larvae from the malaria endemic sub-district of Bobirwa and non-endemic sub-districts of Palapye and Serowe, to determine spatial mosquito abundance and diversity in the District.
- Full Text:
- Date Issued: 2023
Oxpecker host-selection in the Salambala conservancy, northeastern Namibia
- Authors: Lukubwe, Michael S , Craig, Adrian J F K , Manyangadze, Tawanda
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449934 , vital:74866 , https://doi.org/10.3957/056.053.0166
- Description: By studying the host-selection patterns of oxpecker species, researchers can gain valuable insights into their ecological roles and interactions with different host species. This information is crucial for developing effective conservation strategies that prioritise the protection of oxpeckers and their host populations. The study conducted field observations and recorded data on the number of oxpeckers and their respective host species. Additionally, this study investigated the relationship between host species and host parameters (body mass and hair length) in the Salambala conservancy in northeastern Namibia. Selection and density indices were used to calculate the number of host animals supporting one oxpecker as well as the oxpecker density on a host's body surface. Pentad-based counts of oxpeckers and ungulates were conducted.
- Full Text:
- Date Issued: 2023
Persistent effects of historical sea levels on the population structure of a temporary wetland copepod
- Authors: Emami-Khoyi, Arsalan , Jooste, Candice M , Wasserman, Ryan J , Dalu, Tatenda , Raath-Krüger, Morgan J , Jansen van Vuuren, Bettine , Teske, Peter R
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445115 , vital:74348 , https://doi.org/10.1111/fwb.14139
- Description: Temporary wetland ecosystems are common in arid and semi‐arid envi-ronments, and are inhabited by diverse invertebrate communities. Little is known about the dynamics of genetic connectivity in the geograph-ically scattered populations of these wetland specialists. The current study investigated the spatial genetic structure and dispersal history of a recently described calanoid copepod, Lovenula raynerae, reported from temporary wetlands in the Eastern Cape province of South Africa. We tested whether the species represents a single, well‐connected population or comprises different regional genetic groups, some of which may be rare or endangered.
- Full Text:
- Date Issued: 2023