Red and other short stories
- Authors: Harrison, Francis J
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/141583 , vital:37987
- Description: Part A: Thesis (Creative Work);Part B: Portfolio. Final submission for the degree of Master of Arts in Creative Writing (MACW).
- Full Text:
- Date Issued: 2020
Reef fish associations with benthic habitats at a remote protected coral reef ecosystem in the Western Indian Ocean-Aldabra Atoll, Seychelles
- Authors: Haupt, Philip
- Date: 2020
- Subjects: Coral reef ecology -- Aldabra Islands (Seychelles) , Reef fishes -- Aldabra Islands (Seychelles) , Benthic animals -- Aldabra Islands (Seychelles)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/141629 , vital:37991
- Description: The aim of the thesis is to develop an understanding of the associations between reef fish and benthic habitats and assess the modifying effects of environmental processes on these relationships at Aldabra, a pristine atoll in the Western Indian Ocean (WIO). Conducting research in pristine, or reference coral reef ecosystem, removes the impact of direct anthropogenic disturbances and provides essential information on natural ecosystem structure and functioning. Three primary hypotheses were tested: 1) Environmental drivers such as depth and exposure to wave energy determine the spatial distribution of benthic habitats; 2) The reef fish assemblage structure is explained by habitat at multiple scales and modified by the effects of environmental drivers such as depth, wave energy and cyclical temporal drivers such as time and tides; 3) The reef fish assemblage at Aldabra represents a pristine reef fish assemblage, comprising high levels of herbivores and predators. The research focussed on the benthic habitat on the seaward reefs between the shoreline and 50 m depth. The first objective was to characterise the benthic habitats on Aldabra Atoll’s seaward reefs and map their spatial distributions using remotely sensed imagery and ground truthing data. The second was to assess the influence of depth and exposure to wave energy on the distribution of benthic habitats. The third was to identify the most suitable standardised method to survey the reef fish assemblage structure on Aldabra’s, and fourth to determine the effect of tide and time of day on the reef fish assemblage. The fifth objective was to establish the association between reef fish assemblage structure and benthic habitats and to test how species-size influenced the scale of habitat at which the associations were most apparent. Four categories of geomorphic reef zones (reef flats (19.2 km2), top of the forereef slope (7.8 km2), deep forereef slope (11.6 km2), and reef platform (14.3 km2)) were manually delineated following the visual outlines of reef features from satellite imagery. The six broad-scale and twelve fine-scale benthic habitats were mapped using a supervised maximum likelihood classification and the spatial coverage of each determined. The broad-scale habitats were 1) Epilithic algal matrix, 2) Hard and soft (coral, 3) Rubble, 4) Macroalgae, 5) Seagrass and 6) Sand. Similarly, twelve fine-scale benthic habitats were characterised and mapped, for example, Hard coral (19 %) including massive and submassive forms with Millepora and Rhytisma. The broad-scale benthic habitat map had an overall producer accuracy of 54 % and fine-scale habitat map 29 %, which was consistent with studies using similar habitat classification methods. The prevailing wave energy, depth and the directional orientation of coral reefs (aspect) significantly influenced the probability of occurrence of each of the broad-scale benthic habitats, and there was a shift in peak probability of occurrence of all habitat categories to a greater depth with an increase in wave energy. The strong relationship of benthic habitats with depth and wave energy suggests that the distributions of benthic habitats are likely to change with sea-level rise and increased intensity and frequency of storms in future. Overall, 338 fish species from 51 families, including 14 species of elasmobranch were recorded using Baited Remote Underwater Video systems (BRUVs) and unbaited Remote Underwater Video systems (RUVS) from 231 samples. Fish were significantly more abundant when observed using BRUVs (119 ± 7) relative to RUVs (92 ± 7), and the assemblage structures were significantly different between the two sampling methods. Abundance and species richness of generalist carnivores and piscivores were significantly greater in BRUVs, while RUVs recorded significantly greater numbers of herbivores and more species of herbivore and corallivore. The results suggest that BRUVs are better suited when studying predatory fish which may not be detected without bait. However, when surveying a taxonomically and functionally diverse assemblage of fishes at a pristine reef, RUVs may provide a more accurate estimate of natural reef fish assemblage structure. Reef fish assemblages observed using RUVs were significantly different between morning-high-tide, midday-low-tide and evening-high-tide for all trophic groups. However, the reef fish assemblage structure observed using BRUVs was insensitive to change in tide and time of day, which may be explained by the attraction effect of bait dampening the effect of tide and time of day. While RUVs appear better to detect more subtle variations in fish assemblage structure, care needs to be taken when designing research programmes that use RUVs, as the sampling design should account for tide and time of day to avoid misinterpreting the cyclical variation, which may confound results. Reef fish assemblages were significantly different among habitats within geomorphic reef zones, broad-scale and fine-scale habitats. Species turnover rates were significantly different for all Actinopterygii size-class categories between the three scales of habitat. No marked differences in species turnover rates among habitats were detected for the majority of Elasmobranch size-class categories. The strong habitat dependency over various spatial scales indicates that effective conservation of Actinopterygii fish at Aldabra, and elsewhere in similar ecosystems requires protection of representative sets of benthic habitats. However, Elasmobranch conservation requires sufficiently large areas as these species utilise multiple habitats, over multiple scales, which are likely to exceed the confines of Aldabra’s reef.
- Full Text:
- Date Issued: 2020
Registered nurses’ experiences of trust in the workplace in Eastern Cape public hospitals
- Authors: Holland, Ashleigh Simone
- Date: 2020
- Subjects: Teams in the workplace -- South Africa -- Eastern Cape , Communication in organizations Trust
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/50579 , vital:42255
- Description: Trust is fundamental to building and maintaining positive relationships and leads to favourable outcomes for teams and organisations. Research focusing on trust has gained popularity in recent years as researchers seek to gain an understanding and insight into this concept. The importance of examining trust from both perspectives of the organisational dyad (employer-employee) is emphasised, yet much of the research focuses on the employer’s perspective. The researcher identified a gap in trust literature pertaining to the nursing work environment and sought to examine this phenomenon from the employees’ perspective, with an emphasis on both horizontal and vertical trust relationships. Therefore, the aim of the study was to explore and describe trust experiences of registered nurses working in general wards in public hospitals of the Nelson Mandela Bay Health District (NMBHD). The study employed a qualitative, phenomenological design and was exploratory and descriptive in nature to gain insight into and depict the lived experiences of trust between participants and their peers and between participants and their superiors and subordinates. Sampling was purposive, and 14 individual, semi-structured, face-to-face interviews were conducted so that participants could describe their experiences of the phenomenon under investigation in their own words. The data was analysed using Renata Tesch’s data coding and analysis technique. Three themes emanated from the data, namely: (1) Influence of connected and caring relationships on trust among registered nurses; (2) Influence of professional competence on trust among registered nurses; and (3) Influence of values on trust among registered nurses. The findings revealed that trust or the lack of trust is a critical component underpinning the variety of relationships that exist in the general ward hospital environment. Furthermore, for registered nurses, the competence or lack of competence of colleagues serves to instil or undermine trust among one another. In addition, owing to the nature of the profession, registered nurses place a great emphasis on values, especially as these relate to patient care, and the presence or absence of these values serve to build or undermine trust among registered nurses. It is evident that trust needs to be present in order to enhance interpersonal relationships among registered nurses (and other colleagues) and thereby maintain or enhance quality patient care. Hence, the study revealed that trust is a complex phenomenon, particularly in the hospital setting, and experiences and perceptions of trust differ among registered nurses. The findings highlighted the need for management to find ways of nurturing and building trust among registered nurses themselves and between registered nurses and their health worker colleagues.
- Full Text:
- Date Issued: 2020
Registered Nurse’s experiences of trust in the workplace in Eastern Cape public hospitals
- Authors: Holland, Ashley Simone Anderson
- Date: 2020
- Subjects: Public health nurses -- South Africa -- Eastern Cape , Trust -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/49854 , vital:41809
- Description: Trust is fundamental to building and maintaining positive relationships and leads to favourable outcomes for teams and organisations. Research focusing on trust has gained popularity in recent years as researchers seek to gain an understanding and insight into this concept. The importance of examining trust from both perspectives of the organisational dyad (employer-employee) is emphasised, yet much of the research focuses on the employer’s perspective. The researcher identified a gap in trust literature pertaining to the nursing work environment and sought to examine this phenomenon from the employees’ perspective, with an emphasis on both horizontal and vertical trust relationships. Therefore, the aim of the study was to explore and describe trust experiences of registered nurses working in general wards in public hospitals of the Nelson Mandela Bay Health District (NMBHD). The study employed a qualitative, phenomenological design and was exploratory and descriptive in nature to gain insight into and depict the lived experiences of trust between participants and their peers and between participants and their superiors and subordinates. Sampling was purposive, and 14 individual, semi-structured, face-to-face interviews were conducted so that participants could describe their experiences of the phenomenon under investigation in their own words. The data was analysed using Renata Tesch’s data coding and analysis technique.
- Full Text:
- Date Issued: 2020
Regularly drinking desert birds have greater evaporative cooling capacity and higher heat tolerance limits than non‐drinking species
- Authors: Czenze, Zenon J , Kemp, Ryno , van Jaarsveld, Barry , Freeman, Marc T , Smit, Ben , Wolf, Blair O , McKechnie, Andrew
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441585 , vital:73900 , https://doi.org/10.1111/1365-2435.13573
- Description: Surface water is a critical resource for many birds inhabiting arid re-gions, but the implications of regular drinking and dependence on sur-face water for the evolution of thermal physiology remain largely unex-plored. We hypothesized that avian thermoregulation in the heat has evolved in tandem with the use of surface water and predicted that (a) regularly drinking species have a greater capacity to elevate rates of evaporative water loss (EWL) compared to non‐drinking species, and (b) heat tolerance limits (HTLs) are higher among drinking species. To test these predictions, we quantified thermoregulatory responses to high air temperature (Ta) in 12 species of passerines from the South African arid zone and combined these with values for an additional five species. We categorized each species as either: (a) water‐dependent, regularly drinking, or (b) water‐independent, occasional‐/non‐drinking.
- Full Text:
- Date Issued: 2020
Regulation of Kaposi’s Sarcoma-Associated Herpesvirus Biology by Host Molecular Chaperones:
- Authors: Kirigin, Elisa , Ruck, Duncan Kyle , Jackson, Zoe , Murphy, James , McDonnell, Euan , Okpara, Michael O , Whitehouse, Adrian , Edkins, Adrienne L
- Date: 2020
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/165385 , vital:41239 , ISBN , https://0-doi.org.wam.seals.ac.za/10.1007/7515_2020_18
- Description: Kaposi’s sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus associated with development of the human diseases Kaposi’s sarcoma, Primary Effusion Lymphoma and Multicentric Castleman’s Disease. KSHV establishes a chronic latent infection in hosts, with periods of viral lytic replication, where both latent and lytic virus cycles contribute to malignancy, most often in the immunodeficient host.
- Full Text:
- Date Issued: 2020
Reimagining academic identities in response to research demands at Universities of Technology
- Authors: Gumbi, Thobani , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185897 , vital:44446 , xlink:href="https://doi.org/10.14426/cristal.v8i1.234"
- Description: In the last volume of this journal, Garraway and Winberg called for a reimagination of Universities of Technology (UoT) within the South African higher education system. This article continues that conversation by looking at the implications that the formation of the UoT had for academics’ identities. Technikon lecturers’ identities were closely tied to workplace expertise, but demands for research in UoTs have changed this. A social realist analysis of interviews with fifteen academics at three UoTs finds that research remains a contested issue. Interviewees understood research to take the form of acquiring postgraduate qualifications, rather than as an ongoing activity tied to their identities. Echoing Garraway and Winberg’s study, the bureaucratic nature of the institutional culture was referred to as a constraint. There was also a view that for this programme, Dental Technology, a demand for research was needed from industry if this was to be a valued aspect of academics’ identities.
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- Date Issued: 2020
Rejection of the genetic implications of the “Abundant Centre Hypothesis” in marine mussels
- Authors: Ntuli, Noxolo N , Nicastro, Katy R , Zardi, Gerardo I , Assis, Jorge , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444839 , vital:74302 , https://www.nature.com/articles/s41598-020-57474-0
- Description: The ‘Abundant-Centre Hypothesis’ is a well-established but controversial hypothesis stating that the abundance of a species is highest at the centre of its range and decreases towards the edges, where conditions are unfavourable. As genetic diversity depends on population size, edge populations are expected to show lower intra-population genetic diversity than core populations, while showing high inter-population genetic divergence. Here, the genetic implications of the Abundant-Centre Hypothesis were tested on two coastal mussels from South Africa that disperse by means of planktonic larvae, the native Perna perna and the invasive Mytilus galloprovincialis. Genetic structure was found within P. perna, which, together with evidence from Lagrangian particle simulations, points to significant reductions in gene flow between sites. Despite this, the expected diversity pattern between centre and edge populations was not found for either species. We conclude that the genetic predictions of the Abundant-Centre Hypothesis are unlikely to be met by high-dispersal species with large population sizes, and may only become evident in species with much lower levels of connectivity.
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- Date Issued: 2020
Relational hubs for collaborative landscape stewardship
- Authors: Cockburn, Jessica J , Cundill, Georgina , Shackleton, Sheona E , Cele, Ayanda , Cornelius, Susanna F , Koopman, Vaughan , Le Roux, Jean-Pierre , McLeod, Nicky , Rouget, Mathieu , Schroder, Samantha , Van den Broek, Dieter , Wright, Dale R , Zwinkelse, Marijn
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392748 , vital:68789 , xlink:href="https://doi.org/10.1080/08941920.2019.1658141"
- Description: Landscape stewardship is considered an important place-based approach to addressing sustainability challenges. Working at landscape-level requires collaboration between diverse landscape stakeholders. In this study, we partnered with local stewardship practitioners across six cases in South Africa to investigate how they facilitate collaboration towards social-ecological sustainability outcomes. We found that practitioners facilitate collaboration among stakeholders by operating as relational hubs in the landscape. Through these hubs, they build new inter-personal relationships among stakeholders, creating social networks which enable stewardship practice. The hubs deepen human-nature relationships by creating enabling conditions for stewards to put stewardship ethics into action. Drawing on insights from these cases, we call for a relational approach to landscape stewardship which focuses on human-to-human and human-to-nature relationships. Moreover, we argue that landscape stewardship initiatives need to re-focus stewardship on stewards, recognizing them as key agents of change in addressing the conflict between agriculture and conservation inherent in many landscapes.
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- Date Issued: 2020
Relevant knowledge: content analysis of research conducted by South African psychology masters students (2008-2012
- Authors: Whitehead, Tracey
- Date: 2020
- Subjects: Psychology -- Research -- South Africa , Psychology -- Study and teaching (Higher) -- South Africa , Psychology students -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/167683 , vital:41503
- Description: In South Africa, Psychology has had a chequered past mainly due to its role in the justification of apartheid policies. Due to apartheid's socio-economic injustices, confidence in the applicability of psychological knowledge to South Africa's social problems was insufficient. Psychologists attempted to raise consciousness of the social relevance of psychology by contributing relevant knowledge and being reactive to social inequalities and related psychosocial issues affecting South Africa. This study aimed to conduct a content analysis of trends in research produced by Psychology Masters' students in the fields of Clinical, Counselling and Research psychology over a period of 5 years (2008-2012). The corpus of data was then compared with the key issues raised in the United Nations Development Programme's South Africa human development report (2003), along with a focus on articles published by Macleod (2004) and Macleod and Howell (2013). It emerged that Empirical Qualitative studies, based on post-modern frameworks, as well as HIV/AIDS, Knowledge Production, Assessment and Measurement and Programme development and evaluation, dominated psychological research. Participants were mainly urban, middle class adults living in the 3 wealthiest provinces. University students were the most popular participant group. While it is encouraging that students were attempting to engage with psychosocial issues, the limited number of key social issues addressed, the under-representation of certain sectors of the South African population, as well as the impact of socioeconomic status on well-being requires greater attention at Masters' level to ensure Psychology's psychosocial relevance.
- Full Text: false
- Date Issued: 2020
Reliving it through pen
- Authors: Chidi, Tsosheletso
- Date: 2020
- Subjects: South African fiction (English) , Northern Sotho poetry
- Language: English , Northern Sotho
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/163566 , vital:41049
- Description: This document consists of two parts: PART A: English Half Thesis (Creative Work) PART B: Dual Language Portfolio (Sepedi and English). This thesis focuses on witnessing the trauma of rape, inability to move on, denial and attempt to forget, it draws attention also to emotional abuse in a place called home, death and place. My work is influenced by Carolyn Fourche’s anthology, Against Forgetting: Poetry of Witness, Adam Bradley and Andrew Dubois’s The Anthology of the Rap, as well as Lesego Rampolokeng poem “Welcome to New Consciousness”.
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- Date Issued: 2020
Remedial program on learners’ proficiency in english second language: a case of two township schools in king William’s town education district.
- Authors: Moyo, Thembekile
- Date: 2020
- Subjects: Reading -- Remedial teaching Reading (Elementary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/17910 , vital:41977
- Description: Literature indicates that there is a national crisis about learners who cannot read for comprehension at the primary level. However, there is limited literature that talks about effective remediation programmes in developing countries. This had a negative impact on the Matric results in the past years. Statistics have always shown the rural provinces such as Eastern Cape to be the most affected province with these poor results, due to the low levels of learners’ reading skills. This study focused on the remedial programme on learners’ proficiency in English second language, which was conducted in two township schools in King William’s Town District. This explored the remedial programme that could be used to help learners become proficient readers who could be able to read for meaning and comprehension. A case study research design was used where two township schools were sampled. A qualitative approach located in the interpretive paradigm was used to carry out the study. The purposive and the sampling procedure were used to solicit information from principals, educators, and learners. The data was collected through interviews, observations and focus groups. Its focus was to establish a remedial programme to improve learners’ proficiency in English second language. The findings revealed that a lack of English proficiency has a negative effect on the learners’ performance. The findings also revealed that the repetition of concepts helps the learners to master and increase their vocabulary and comprehension. A need for learner teacher support materials (LTSM) was revealed to equip the educators with knowledge and skills for teaching diversity in the classroom. The study recommends provision for trained remedial educators in all schools to attend to the individual needs of learners appropriately. Universities should include a component of remedial education in the training of educators, as they are the ones expected to remediate the struggling learners. Parents should encourage their children to be actively involved in learning the language of teaching and learning.
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- Date Issued: 2020
Reporting drought: framing an anthropogenic natural disaster in the South African mainstream publication, City Press, over three years (2015-2018)
- Authors: Matyobeni, Thandiwe
- Date: 2020
- Subjects: City Press , City Press -- Criticism, Textual , Droughts -- South Africa , Mass media and the environment -- South Africa , Climatic changes in mass media -- South Africa , Press -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/143179 , vital:38208
- Description: This study interrogates how the ongoing anthropogenic drought, declared a disaster in five South African provinces in 2015, has been represented by mainstream news media. The news media enables public participation which is vital to climate action and the regulation of harmful neoliberal practices that fuel climate change and are thus necessary to provide information about climate change and to support political interventions. Despite the gravity of the drought crisis, there is a severe lack of public opinion about it and the complex weather patterns to which it is attributed. This study thus investigates how the drought has been framed by mainstream news media in South Africa, confining itself to a single title, the City Press. To analyse representations of drought in the City Press, this study adopts a Foucauldian approach to discourse which considers representations as meaning constructed through language. The knowledge perpetuated in news texts is thus frequently perceived as the ‘truth’ about the drought. This knowledge is imbued with power as those in positions of authority determine what is articulated as truth. Through various institutional practices, journalists limit what is said about the drought, framing it in particular ways and privileging particular voices. What the public learns about the drought (and in turn, climate change) is thus limited by the norms and routines of the journalistic regime and the corporate nature of ownership. Notably, the City Press operates within the neoliberal economic order to which climate change is attributed. This study is located within the Cultural Studies and Journalism Studies paradigms and is further informed by a qualitative methodology and two methods of textual analysis, that is, thematic analysis and Critical Discourse Analysis. The sampling process produced a database of 26 news texts published by the City Press between the years 2015 to 2018. Five texts were purposively selected for an in-depth analysis based on a broad thematic analysis as reasonably representative of the discourses that recur. Although the City Press positions itself as a critical purveyor of political information, only three themes recur in the texts. These themes position drought in relation to the agricultural economy and urban infrastructure; foreground the voices of corporate entities; while the climate science behind weather patterns is inadequately interpreted. Any discussion of climate change and alternatives to mainstream economic practices is almost entirely omitted.
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- Date Issued: 2020
Reporting on home: how journalists from rural Botswana experience covering rural development while working at the Botswana Daily News
- Authors: Lekoma, Bame Dirakano
- Date: 2020
- Subjects: Botswana -- In mass media , Journalists -- Botswana , Rural development -- Botswana
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/146566 , vital:38537
- Description: The study investigates how journalists working for state media in Botswana experience reporting on development in rural communities. It is observed that many of these journalists are members of the rural communities they report on and therefore have personal knowledge of them. Furthermore, it describes how even though Botswana is often praised for its developmental achievements, the country continues to be characterized by social inequality. The study then articulates a theoretical framework designed to engage with the normative guidelines that inform journalistic practice within the Botswana media landscape. It draws, for this purpose, on normative theories of the press. It is concluded that the Botswana media landscape is representative of an authoritarian, polarised pluralised media system in which journalists work under strict control of the state. The empirical component of the study draws on this framework by conducting life history interviews of journalists working at the Botswana Daily News. It examines what such journalists know from personal experience about development from rural Botswana and how such knowledge impacts on their engagement with the processes of reporting for the paper. It is concluded that journalists working for this paper have a deep commitment to representing the interests of rural communities. However, they remain constrained in their ability to act on this commitment, in context of the guidelines for reporting that frame their institutional context.
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- Date Issued: 2020
Repurposing a polymer precursor scaffold for medicinal application: Synthesis, characterization and biological evaluation of ferrocenyl 1,3-benzoxazine derivatives as potential antiprotozoal and anticancer agents
- Authors: Mbaba, Mziyanda
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164502 , vital:41124 , DOI 10.21504/10962/164502
- Description: The benzoxazines are a prominent class of heterocyclic compounds that possess a multitude of properties. To this end, benzoxazine derivatives have been used as versatile compounds for various utilities ranging from biological applications to the fabrication of polymers. Particularly, the 1,3-benzoxazine scaffold has featured in several bioactive compounds showing antimalarial, anticancer and antibacterial activities. Traditionally, it has been employed as a substrate in the synthesis of polymers with appealing physical and chemical properties. Due to the increasing interest in the polymer application of 1,3-benzoxazines, research of the 1,3-benzoxazine motif for polymer synthesis has been prioritized over other applications including its medicinal potential. The continuous development of resistance to clinical anticancer and antimalarial drugs has necessitated the need for the search of innovative bioactive compounds as potential alternative medicinal agents. To address this, the field of medicinal chemistry is adapting new approaches to counter resistance by incorporating nonconventional chemical moieties such as organometallic complexes, like ferrocene, into bioactive chemical motifs to serve as novel compounds with medicinal benefits. Incorporation of ferrocene into known bioactive chemical moieties has been shown to impart beneficial biological effects into the resultant compounds, which include the introduction of novel, and sometimes varied, mechanistic modalities and enhanced potency. Presented with the benefits of this strategy, the current work aims to design and evaluate the pharmaceutical capacity of novel derivatives containing 1,3-benzoxazine scaffold (traditionally applied in polymer synthesis) hybridized with the organometallic ferrocene unit as bioactive agents. Using a combination of expedient synthetic procedures such as the Burke three-component Mannich-type condensation, Vilsmeier-Haack formylation and reductive amination, four series of ferrocenyl 1,3-benzoxazine derivatives were synthesized and their structures confirmed by common spectroscopic techniques: nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The target compounds were evaluated in vitro for potential antimalarial and anticancer activities against strains of the malaria parasite (Plasmodium falciparum 3D7 and Dd2) and the triple-negative breast cancer cell line HCC70. Compounds exhibited higher potency towards the Plasmodium falciparum strains with IC50 values in the low and sub-micromolar range in comparison to the breast cancer cell line against for which mid-molar activities were observed. To gain insight into the possible mode of action of ferrocenyl 1,3-benzoxazines, representative compounds showing most efficacy from each series were assessed for DNA binding affinity by employing UV-Vis and fluorescence DNA titration experiments. The selected compounds were found to interact with the DNA by binding to the minor groove, and these findings were confirmed by in silico ligand docking studies using a B-DNA structure as the receptor. Compound 3.16c (IC50: 0.261 μM [3D7], 0.599 μM [Dd2], 11.0 μM [HCC70]), which emerged as the most promising compound, was found to induce DNA damage in HCC70 cancer cells when investigated for effects of DNA interaction. Additionally, compound 3.16c displayed a higher binding constant (Kb) against DNA isolated from 3D7 Plasmodium falciparum trophozoites (Kb = 1.88×106 M-1) than the mammalian DNA (Kb = 6.33×104 M-1) from calf thymus, thus explaining the preferred selectivity of the compounds for the malaria parasite. Moreover, the investigated compounds demonstrated binding affinity for synthetic hemozoin, β-hematin. Collectively, these data suggest that the compounds possess a dual mode of action for antimalarial activity involving DNA interaction and hemozoin inhibition. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
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- Date Issued: 2020
Repurposing a polymer precursor: Synthesis and in vitro medicinal potential of ferrocenyl 1, 3-benzoxazine derivatives
- Authors: Mbaba, Mziyanda , Dingle, Laura M K , Cash, Devon , de la Mare, Jo-Anne , Laming, Dustin , Taylor, Dale , Hoppe, Heinrich C , Edkins, Adrienne L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165395 , vital:41240 , https://doi.org/10.1016/j.ejmech.2019.111924
- Description: Cancer and malaria remain relevant pathologies in modern medicinal chemistry endeavours. This is compounded by the threat of development of resistance to existing clinical drugs in use as first-line option for treatment of these diseases. To counter this threat, strategies such as drug repurposing and hybridization are constantly adapted in contemporary drug discovery for the expansion of the drug arsenal and generation of novel chemotypes with potential to avert or delay resistance. In the present study, a polymer precursor scaffold, 1,3-benzoxazine, has been repurposed by incorporation of an organometallic ferrocene unit to produce a novel class of compounds showing in vitro biological activity against breast cancer, malaria and trypanosomiasis.
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- Date Issued: 2020
Researching mobile phones in the everyday life of the “less connected”: the development of a New Diary Method
- Authors: de Lanerolle, Indra , Schoon, Alette , Walton, Marion
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160413 , vital:40443 , DOI: 10.1080/23743670.2020.1813785
- Description: This article introduces our mobile diary method, a qualitative method for the study of mobile phone practices. Adapted from the diary methods of psychology and media studies audience research, it is designed to foreground tacit and mundane data about everyday mobile phone practices. The diary interview reconstructs details of the social practices of everyday life that make up each participant’s “yesterday” and situates mobile practices within this account. To illustrate the method, we provide examples from our study, Izolo, that spanned three distinct South African neighbourhoods in different parts of the country and focused on less-connected people.
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- Date Issued: 2020
Resisting abortion stigma in situ: South African womxn's and healthcare providers' accounts of the pre-abortion counselling healthcare encounter
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443749 , vital:74149 , xlink:href="https://doi.org/10.1080/13691058.2019.1674922"
- Description: Abortion providers and pregnant people who undergo abortion potentially face significant stigma. Researchers have started to explore how womxn respond to abortion stigma, usually focusing on individual strategies in managing or reducing stigma effects. Drawing on narrative data from research conducted on womxn’s and healthcare providers’ experiences of the pre-abortion healthcare encounter in the South African public health sector, we highlight how stigma may be resisted in social ways within this context. Everyday chatter and informal social support amongst womxn in the waiting room provided a counterpoint for health service providers’ ascription of shame to the womxn, and a sense of solidarity amongst the womxn. Health service providers narrated their decision to do abortion work through the socially affirming hero canonical narrative, and womxn described their counselling as helpful. These social and discursive practices resist the awfulisation of abortion and provide relief for the womxn and the healthcare providers in particular contexts.
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- Date Issued: 2020
Resisting the ‘Native Informant’ trope in examples of African Diaspora art and literature
- Authors: Nuen, Tinika
- Date: 2020
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/131657 , vital:36708
- Description: This thesis draws attention to the existence of the ‘native informant’ trope in the African Diaspora. It argues that a strong emphasis towards studying diasporic groups in relation to their African origin revives, consequently, the colonial politics that underpin the continent as an unknown mythical place. In response to this issue, I introduce multidisciplinary case studies that highlight various artists and authors who resist and challenge the diasporic individual as the ‘native informant’. Their works reinterpret and redefine the relationship between African communities, their connection to the continent and their experiences of living abroad. Analysing the exhibitions Looking Both Ways, Africa Remix and Flow, I investigate their visual art discourses that interpret diasporic artists and their works as cultural embodiments of their African background. As a result, the three art shows marginalise other potential readings to view diasporic experiences. This thesis introduces three resistant themes that reconceive the diasporic person’s relationship to the African Diaspora based on language, spatial interaction and self-identification opposed to a geographic tie. The first theme (language) references Victor Ekpuk’s drawings and Isidore Okpewho’s novel Call Me By My Rightful Name to suggest a language based diasporic experience. The second theme (spatial interaction) looks at Emeka Ogboh’s sound installations and Teju Cole’s novel Open City. Both works examine a diasporic individual’s conflicted engagement with her place of origin. The third theme (self-identification) considers the individual-community relationship in Wura-Natasha Ogunji’s performance art and Chika Unigwe’s novel On Black Sisters’ Street. Each of these visual-literary pairs focus on various components that shape the African diasporic lifestyle. My research re-interprets the continent’s significance in the diaspora from a geographic construct to a socio-spiritual connection to a community. Firstly, it outlines the persistent issue of a colonial residue in Africa’s definition as a physical-cultural space, and secondly, it offers three alternative discourses to read diasporic identities outside a geographic framework. I argue that belonging is a social individual-collective effort rather than an anchor to a tangible environment.
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- Date Issued: 2020
Resource Allocation Framework in Fog Computing for the Internet of Things Environments
- Authors: Vambe, William Tichaona
- Date: 2020
- Subjects: Internet of things Cloud computing
- Language: English
- Type: Thesis , Doctoral , PhD (Computer Science)
- Identifier: http://hdl.handle.net/10353/18498 , vital:42575
- Description: Fog computing plays a pivotal role in the Internet of Things (IoT) ecosystem because of its ability to support delay-sensitive tasks, bringing resources from cloud servers closer to the “ground” and support IoT devices that are resource-constrained. Although fog computing offers some benefits such as quick response to requests, geo-distributed data processing and data processing in the proximity of the IoT devices, the exponential increase of IoT devices and large volumes of data being generated has led to a new set of challenges. One such problem is the allocation of resources to IoT tasks to match their computational needs and quality of service (QoS) requirements, whilst meeting both task deadlines and user expectations. Most proposed solutions in existing works suggest task offloading mechanisms where IoT devices would offload their tasks randomly to the fog layer or cloud layer. This helps in minimizing the communication delay; however, most tasks would end up missing their deadlines as many delays are experienced during offloading. This study proposes and introduces a Resource Allocation Scheduler (RAS) at the IoT-Fog gateway, whose goal is to decide where and when a task is to be offloaded, either to the fog layer, or the cloud layer based on their priority needs, computational needs and QoS requirements. The aim directly places work within the communication networks domain, in the transport layer of the Open Systems Interconnection (OSI) model. As such, this study follows the four phases of the top-down approach because of its reusability characteristics. To validate and test the efficiency and effectiveness of the RAS, the fog framework was implemented and evaluated in a simulated smart home setup. The essential metrics that were used to check if round-trip time was minimized are the queuing time, offloading time and throughput for QoS. The results showed that the RAS helps to reduce the round-trip time, increases throughput and leads to improved QoS. Furthermore, the approach addressed the starvation problem, a phenomenon that tends to affect low priority tasks. Most importantly, the results provides evidence that if resource allocation and assignment are appropriately done, round-trip time can be reduced and QoS can be improved in fog computing. The significant contribution of this research is the novel framework which minimizes round-trip time, addresses the starvation problem and improves QoS. Moreover, a literature reviewed paper which was regarded by reviewers as the first, as far as QoS in fog computing is concerned was produced.
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- Date Issued: 2020