Structure and interaction studies of beta-amyloid in the search for new lead compounds for the treatment of Alzheimer’s disease
- Authors: Mtini, Onke
- Date: 2020
- Subjects: Alzheimer's disease -- Chemotherapy , Alzheimer's disease -- Treatment , Amyloid beta-protein , Oxidative stress , Protein binding , South African Natural Compounds Database
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167574 , vital:41493
- Description: Alzheimer’s disease (AD) is the most devastating neurodegenerative disorder that effects the aging population worldwide. In this study three hypotheses of AD are explored, the β-amyloid cascade hypothesis, the β-amyloid metal binding hypothesis and the oxidative stress hypothesis are explored. In the first case compounds from the South African Natural Compounds Database (SANCDB) are docked to models of β-amyloid fibrils and the properties of these fibrils under pulling simulations are compared to a known small molecule disruptor of β-amyloid, wgx-50. In these simulations SANCDB compounds are identified that disrupt β-amyloid in a similar manner to wgx-50. In these simulations the disruption to the free energy of binding of chains to the fibrils is quantified. For metal binding and oxidative stress hypotheses, problems in simulation arise due to only fragments of β-amyloid being present in the Research Collaboratory for Structural Bioinformatics protein data bank (RCSB PDB), as determined from NMR experiments. In this work, β-amyloid is set up under periodic boundary conditions to simulate a fibril under reasonable computational time. Within these periodic boundary conditions, β-amyloid has been solvated in copper and zinc rich environments and diffusion of these metals around the fibrils has been explored. The localization of these metals (in simulation only using van der Waal’s and electrostatic terms) around the fibril has led us to explore other possible metal binding sites. Metal bound to the infinite fibril has been optimized at the QM/MM level and some of the reactive oxygen species in the presence of the fibril are quantified.
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Symmetry and asymmetry in electrocatalysis: enhancing the electrocatalytic activity of phthalocyanines through synergy with doped graphene quantum dots
- Authors: Nkhahle, Reitumetse Precious
- Date: 2020
- Subjects: Phthalocyanines , Quantum dots , Graphene
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/117585 , vital:34529
- Description: An exploration on the enhancement of the electrocatalytic activity of phthalocyanines (Pcs) through coupling with a series of graphene quantum dots (GQDs) is undertaken. The preliminary studies using symmetrical Pcs, a cobalt and an iron chloride tetra substituted diethylaminophenoxy Pc (complexes 1 and 2), for the electro-oxidation of nitrite revealed through the various sequential modifications that doped GQDs fare better than their pristine counterparts with respect to improving the electrocatalytic behaviour of Pcs, in particular, the nitrogen-doped GQDs (NGQDs). Following up on this, a series of asymmetric Pc complexes; 2,9,16-tris-(4-tert-butylphenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (3), 2,9,16-tris-(4-tert-butylphenoxy) mono aminophenoxy phthalocyanato cobalt (II) (4), 2,9,16-tris-(3-diethylamino)phenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (5) and 2,9,16-tris-(3-diethylamino)phenoxy) mono aminophenoxy phthalocyanato cobalt (II) (6) was prepared in which push-pull systems were compared to other asymmetric complexes that lack this effect towards the electrocatalytic sensing of hydrazine. All asymmetric complexes (3-6) were π-stacked to the NGQDs while those with an NH2 group (4 and 6), were also covalently linked to the NGQDs. These complexes and their corresponding conjugates were characterized accordingly and applied as electrocatalysts in the oxidation of hydrazine. The electrochemical studies revealed that π π stacking yields better responses (higher sensitivities and lower limits of detection) than covalent linking because there are less forces acting on the graphene network. Covalent linking introduces both tensile and compressive forces which in turn results in an increase in the ID/IG ratio and that is unfavourable for electrocatalysis. In comparing the electrodes composed of the π-stacked conjugates to those altered through sequential modifications, despite the conditions not being the same, it can be inferred that the magnitude of the electrostatic forces between the Pcs and the GQDs also plays a significant role in electrocatalysis. The π-stacked conjugates, owing to the manner in which they were prepared, have stronger electrostatic forces acting between the Pc and GQDs hence they were able to elicit a better electrochemical response than the sequentially modified electrodes. In addition to that, it appears that asymmetric Pcs are better electrocatalysts in comparison to the symmetric Pcs.
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Synthesis, photophysicochemical properties and photodynamic therapy activities of indium and zinc phthalocyanines when incorporated into Pluronic polymer micelles
- Authors: Motloung, Banele Mike
- Date: 2020
- Subjects: Indium , Zinc , Phthalocyanines , Polymers , Photochemotherapy , Micelles
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167529 , vital:41489
- Description: This thesis reports on the syntheses, photophysicochemical properties and photodynamic therapy activities of symmetrical metallophthalocyanines (MPcs) when alone or when incorporated into Pluronic polymer micelles. The Pcs contain either zinc or indium as central metals and have phenyldiazenylphenoxy, pyridine-2-yloxy and benzo[d]thiazol-2-ylthio as ring substituents. Spectroscopic and microscopic techniques were used to confirm the formation MPcs with micelles. The photophysics and photochemistry of the Pcs were assessed when alone and with micelles. All the studied Pcs showed good photophysicochemical behavior with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yields. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy atom effect obtained from the former. The in vitro dark cytotoxicity and photodynamic therapy of the Pc complexes and conjugates against MCF7 cells was tested. All studied Pc complexes alone and with micelles showed minimum dark toxicity making them applicable for PDT. All complexes displayed good phototoxicity < 50% cell viability (except for complex 2 > 50% cell viability) at concentrations ≤100 μg/mL, however the conjugates showed < 45% cell viability at concentrations ≤ 100 μg/mL, probably due to the small micellar size and EPR effect. The findings from this work show the importance of incorporating photosensitizers such as phthalocyanines into Pluronic polymers micelles and making them water soluble and ultimately improving their photodynamic effect.
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System analysis of fatigue in pilots and co-pilots executing short-hall flight operations
- Authors: Bennett, Cleo Taylor
- Date: 2020
- Subjects: Air pilots -- Health and hygiene , Fatigue , Work environment -- Psychological aspects , Work environment -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146622 , vital:38543
- Description: Background: This study was conducted as part of Denel’s South African Regional Aircraft (SARA) development project. Regional aircraft have a maximum flight time of 60 minutes. Hence, the study focuses on matters pertaining to the short-haul flight context. Pilot fatigue has been recognised as a safety concern in the aviation industry. It impacts on pilot performance across the board, not least in the short-haul context. However, the specific factors that lead to pilot fatigue in short-haul operations have not been well researched. Research Aim: To identify and examine the factors which influence pilot/co-pilot fatigue in short-haul aviation contexts. Method: Fatigue is multifaceted, and has multiple definitions and descriptions. It is acknowledged as a complex phenomenon, the development of which is dynamically influenced by various factors. Thus, a systems approach based on the work system model by Smith and Carayon-Sainfort (1989) was adopted for this study. A systems analysis was conducted in two parts: 1) a literature analysis, and 2) expert interviews. Results: Both the literature analysis and the interviews indicated that pilot fatigue in short-haul flight operations represent composite system outcomes influenced by various factors. The factors identified were structured (systematised) into categories, namely organizational factors, task-related factors, environmental factors, factors linked to technology and tools, and non-work-related factors specific to the individual pilot. An example of a task-related factor would be the performance by pilots of multiple take-offs and landings; organizational factors include work time arrangements and duty scheduling (e.g. unpredictable schedule, early starts/late finishes, number of flight sectors in a shift, extended working hours, numerous consecutive work days, standby duties, flight, duty and rest limitations (regulations and guidelines); and short turnaround periods); environmental factors might include the small pressurised cockpit environment, movement restriction, very low humidity, low air pressure, vibrations, high noise levels, low light intensity light, and inclement weather); there are many examples of how tools and technology utilized by pilots might affect their fatigue levels; and finally, pilot-specific non-work-related factors would include things like the pilot’s age, health (lifestyle), family stress, work experience and sleep environment. All of these factors were identified during the literature analysis and have a significant bearing on how fatigue could present in short-haul pilots/co-pilots. Other important fatigue-related factors revealed during the expert interviews included, organizational culture, time management, health implications of fatigue, and management of fatigue. Conclusions: Pilot fatigue is a complex and multi-factorial physiological condition. There are many interacting components which contribute to pilot fatigue in short-haul operations. These should be viewed from an integrated perspective and holistic, systems-based approaches should be taken to manage these issues, particularly in the context of short-haul operations. This would optimize pilot performance and well-being and, most importantly, improve the safety of the work environment to enhance overall operation safety. Limitations: The study does not quantify the contributions made to pilot fatigue by the various factors explored. Therefore, care needs to be taken when designing and implementing interventions based on this research.
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Tax revolts: an international perspective
- Authors: Tinotenda, Tariro Chizanga
- Date: 2020
- Subjects: Taxation -- Public opinion , Taxation -- Law and legislation -- South Africa , Income tax -- South Africa , South Africa -- Economic conditions , Fiscal policy -- South Africa
- Language: English
- Type: text , Thesis , Masters , MComm
- Identifier: http://hdl.handle.net/10962/166116 , vital:41330
- Description: The main goal of this study is to investigate whether tax revolts currently taking place and apparently threatening to take place in South Africa follow patterns shown in past international tax revolts or follow a unique pattern of their own. Tax revolts or tax rebellions are not a new phenomenon; they can be traced back to the beginning of time. Renowned tax revolts of the past include the Magna Carta and the Peasants’ Revolt in England, the Boston Tea Party, the Whiskey Rebellion, the Zimbabwean poll tax revolt, the Bambatha rebellion, the Tigre Rebellion, Proposition 13 and Margaret Thatcher’s poll tax revolt. These tax revolts were usually caused by the high burden of taxation, excessive government expenditure, corruption of government officials, declining tax morale of taxpayers and taxpayers’ perceptions of unfairness. In South Africa, elements of tax revolts have been on the rise. There has been a tax revolt against the e-tolling system in Gauteng since 2013. Non-payment of municipal rates is another form of tax revolt that has been and is happening in South Africa. Trade unions have also threatened strikes and mass action against various tax changes, including the value-added tax increase. Taxpayers, through media reporting, have been witnessing an increase in the use of taxpayers’ money for non-governmental agendas or overstated budgets. An increasing number of South Africans have been emigrating financially from South Africa to avoid a high taxation burden. The study falls within a post-positivist paradigm and an interpretive methodology is applied in the present research. The methodology is based on the fact that the social reality of tax revolts is not singular or objective, instead it is influenced by human experiences and social contexts. The study finds that tax revolts are currently occurring and threatening to occur in South Africa. The patterns of South African tax revolts are to a great extent similar to the patterns of international tax revolts, indicating the universalism of tax revolts. The study also confirms that South African tax revolts are, to a certain extent, unique.
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Technology in conservation: towards a system for in-field drone detection of invasive vegetation
- Authors: James, Katherine Margaret Frances
- Date: 2020
- Subjects: Drone aircraft in remote sensing , Neural networks (Computer science) , Drone aircraft in remote sensing -- Case studies , Machine learning , Computer vision , Environmental monitoring -- Remote sensing , Invasive plants -- Monitoring
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/143408 , vital:38244
- Description: Remote sensing can assist in monitoring the spread of invasive vegetation. The adoption of camera-carrying unmanned aerial vehicles, commonly referred to as drones, as remote sensing tools has yielded images of higher spatial resolution than traditional techniques. Drones also have the potential to interact with the environment through the delivery of bio-control or herbicide, as seen with their adoption in precision agriculture. Unlike in agricultural applications, however, invasive plants do not have a predictable position relative to each other within the environment. To facilitate the adoption of drones as an environmental monitoring and management tool, drones need to be able to intelligently distinguish between invasive and non-invasive vegetation on the fly. In this thesis, we present the augmentation of a commercially available drone with a deep machine learning model to investigate the viability of differentiating between an invasive shrub and other vegetation. As a case study, this was applied to the shrub genus Hakea, originating in Australia and invasive in several countries including South Africa. However, for this research, the methodology is important, rather than the chosen target plant. A dataset was collected using the available drone and manually annotated to facilitate the supervised training of the model. Two approaches were explored, namely, classification and semantic segmentation. For each of these, several models were trained and evaluated to find the optimal one. The chosen model was then interfaced with the drone via an Android application on a mobile device and its performance was preliminarily evaluated in the field. Based on these findings, refinements were made and thereafter a thorough field evaluation was performed to determine the best conditions for model operation. Results from the classification task show that deep learning models are capable of distinguishing between target and other shrubs in ideal candidate windows. However, classification in this manner is restricted by the proposal of such candidate windows. End-to-end image segmentation using deep learning overcomes this problem, classifying the image in a pixel-wise manner. Furthermore, the use of appropriate loss functions was found to improve model performance. Field tests show that illumination and shadow pose challenges to the model, but that good recall can be achieved when the conditions are ideal. False positive detection remains an issue that could be improved. This approach shows the potential for drones as an environmental monitoring and management tool when coupled with deep machine learning techniques and outlines potential problems that may be encountered.
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The benefits and challenges of implementing the Equator Principles: the case of four large banks in South Africa, through the eyes of project finance teams
- Authors: Baloyi, Glenda
- Date: 2020
- Subjects: Financial institutions -- South Africa -- Moral and ethical aspects , Sustainable development -- South Africa , Project management -- South Africa -- Finance
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/126165 , vital:35855
- Description: The purpose of this research was to investigate the benefits and challenges of implementing the Equator Principles (EPs) by the four large banks in South Africa who are signatories to the framework. This was investigated through the eyes of the project finance teams. The research focused on the perceptions of the project finance team. The EPs are voluntary standards, to date they have been adopted by 94 financial institutions. Financial institutions that have adopted the EPs, benefit by having a competitive advantage of getting involved with high risk projects / developments. The Equator Principles resulted in having environmental and social risk policies and structures to manage these risks. This research was conducted using mixed methods and followed the post-positivist paradigm. The research found that the project finance teams were aware of the environmental, social and governance risks associated with project finance transactions. Furthermore, they understood the need to have the Environmental, Social and Governance (ESG) risk assessment during the credit process. This research found out that the benefits of the EPs outweigh the challenges, as they promote responsible investment, thus promoting the reputation of the investor. The EPs requires the client / borrower to conduct an environmental and social impact assessment and commit to covenants that are binding in the financial legal agreements. By having processes and strategies that promote responsible investment in the financed projects / development, this gives the Equator Principles Financial Institution (EPFI) the advantage of competing in the international market. EPs may indirectly influence the financial institutions that have not adopted the EPs, to promote responsible investment by applying ESG risk assessment processes as required by the banks that have adopted the EPs. EPs lack of capacity such as human resources, policies, funds and structures is the reason why companies do not adopt responsible investment is their operation and not incorporating them in the decision-making process. Some EPFI are not committed the EPs and become free riders. Other EPFI are not complying with the EPs and this causes uncertainties with regards to the legitimacy of the ES standards. EPs are ambiguous, subjective and voluntarism can make it difficult to be achieved by the EPFI. EPs increases the approval process for the financial institution to conclude the transaction, thus delaying the start of a needed project / development. And that EPFI may be forced to have fewer clients as a result of the funding requirements required by EPs.
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The catchup games: a novella
- Authors: Nstumpa, Siya
- Date: 2020
- Subjects: South African fiction (English)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/167222 , vital:41448
- Description: Creative work portfolio.
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The current nature of intra-regional trade in the proposed tripartite free trade area
- Authors: Chibuta, Chisengele
- Date: 2020
- Subjects: Customs unions -- Africa, Southern -- Economic integration , Africa, Southern -- Economic policy , Africa, Southern -- Economic integration , Africa, Southern -- Economic conditions , Tripartite Free Trade Area , Free trade -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/146744 , vital:38553
- Description: This thesis examines and analyses the current nature of intra-regional trade between member states of the proposed Tripartite Free Trade Area in order to contribute to an understanding of the potential for intra-regional trade within the region to increase. Trade Complementarity Indexes were used to determine how well the structures of the three founding blocs’ major imports and exports match. The results show that there is a high degree of trade complementarity in the trade of the top 5 major products traded between the regional groups. With the proposed TFTA in place, high trade complementarity could lead to increased trade between the regional groups. Trade Intensity Indexes were used to determine how intensively the three founding blocs trade with one another. Results from the indexes help determine the extent to which the blocs currently view each other as important trading partners and the implications of this for the proposed TFTA. Results show that EAC and SADC as well as EAC and COMESA viewed each other as significant trading partners while SADC and COMESA did not for the majority of the years from 2001 to 2018. With the TFTA in place, intra-regional trade could be strengthened among the members who currently trade intensively because tariffs between them would be progressively eliminated as required by the TFTA Agreement. Revealed Comparative Advantage Indexes were used to gain insights on whether member states have any comparative advantage in their top 5 exports. Results from the indexes were used to determine whether member states have comparative advantage in similar or dissimilar major exports and the implications of this for the proposed TFTA. Results show that member states have revealed comparative advantage in similar products and these products present opportunities for joint-production among member states as well as sectors for product development once the proposed TFTA is in place. Revealed Trade Barrier Indexes were used to gain insights into the extent of ease of market access into each regional bloc’s market. Results from the indexes indicate whether major products imported from each other receive possibly discriminatory or preferential treatment. The results indicate that the majority of the top 5 imports sourced from each region receive preferential treatment. This indicates that there is ease of market access for the top 5 imports sourced from each other and this could promote increased intra-regional trade among member states in these product categories because tariff and non-tariff barriers to trade will be progressively eliminated once the TFTA is in place.
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The development of teacher leadership: a formative interventionist study in a semi-urban secondary school of Khomas region in Namibia
- Authors: Shilongo, Justina
- Date: 2020
- Subjects: Educational leadership -- Namibia , Educational leadership -- Namibia -- Case studies , Education -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/144923 , vital:38392
- Description: Historically the education system in Namibia was shaped by the policies of the apartheid ideology (Amukugo, 1993). During that time, authority and responsibility were centralised and teachers were not part of the decision making process. By then, most people expected to be told what to do and would not initiate something on their own, a culture inherited that even exists today. In addition, opportunities were not given to teachers to develop as leaders. While Namibians have this history on record, the fact remains that the way in which apartheid laws were put in place, the ideological basis of the policy of apartheid and its impact, was not supportive of the ideas of democracy that Namibia is advocating for today. Despite a number of series of policy guidelines and directives issued to guide the development of a democratic culture in the education sector, less is happening about the leadership of teachers in schools. This stimulated me to conduct an activity theoretical interventionist research, aimed at exploring what opportunities there are for teachers to develop as leaders. This study is a case study, operating from a generative standpoint. The study was conducted in a semi-urban secondary school in Windhoek, Khomas Region, Namibia. The study took a formative intervention approach as it sought to bring about change to practice in the case study school and also to contribute to a body of knowledge in the field of study. This qualitative study employed interviews, observations, document analysis and WhatsApp messaging as data generation tools. Crystallised data revealed multiple realities that demonstrated meaningful and trustworthy data. To analyse data the study employed inductive and abductive analysis to make data meaningful to the reader. Thus, to explore teacher leadership development in a semi-urban secondary school, Change Laboratories Workshops was used as a method to gather and analyse data, as underpinned by 2nd generation CHAT. Grant’s (2017) model of teacher leadership was also used to analyse the data and indicate where teacher leadership roles were mostly visible from all four zones. The findings revealed that there were different understandings of the notion of teacher leadership. It was understood as the possession of certain qualities, a managerial role, an involvement in the decision-making process and a form of social responsibility. It was also revealed that teachers led in all four zones (Grant, 2017b), however participants were not active in all the roles. High participation was noticed in zone one, within the classroom; zone two, leading in curricular and extra-curricular activities and zone four, leading beyond the school into the community. This study explored teacher leadership development and at length identified the conditions that constrained and enabled teachers to develop as leaders in a secondary school. The factors that constrained teacher leadership in the case study school were: lack of time, demanding workloads and other commitments, lack of interest in extramural activities and SMT support for initiatives. Fear and unwillingness to take on leadership roles, narrow views on leadership and ingrained traditional leadership structures, limited leadership capacity building initiatives and the absence of clear educational policies on teacher leadership were also identified. The high involvement in zone one, two and four were attributed to some mechanisms the school put in place to promote teacher leadership, such as through various committees set-up, as well as a culture of mutual care and love. During the change laboratory workshops, teachers opted to be trained in leadership-related matters and to revive the CPD committee.
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The digital and the hyperreal, with reference to artwork by Signe Pierce and Lauren King
- Authors: King, Lauren Pascal
- Date: 2020
- Subjects: Women in art , Femininity in art , Figurative art , Cyberspace -- Social aspects , Feminine beauty (Aesthetics) , Online identities , Photo-realism , Computer art , Virtual reality in art , Reality in art , Art, Modern -- 21st century , Feminist art criticism , Pierce, Signe
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/147939 , vital:38688
- Description: This MFA is a visual art critical investigation of digital representations, manipulations, and exploitations of feminine figures in cyberspace. The particular focus of this study is centred on the work of self-titled reality artist Signe Pierce, as well as my own practical body of work: The Digital Feminine. Case studies of Pierce’s practice include Big Sister (2016), Halo (2018), American Reflexxx (2013) and Reality Hack (2016). Through these case studies I examine the nature of identity formation online as underscored by notions of performativity as well as arguments for the use of feminine aesthetics as feminist critique, specifically through the use of the ‘Venus Flytrapping’ method. Jean Baudrillard famously theorised the hyperreal and the simulacra, claiming that human experience is a simulation of reality1. My MFA thesis addresses contemporary concerns relating to issues of reality, perception, the gaze, and identity in an increasingly virtual world. The 20th century witnessed massive changes in technology, and its subsequent commercialisation marked new territories for mass media, politics, entertainment, social life, and the art world. Avant-garde modern art movements shattered previously held standards of traditional artistic production, thus ideas surrounding the ‘art object’ and the role of artists themselves were fundamentally changed. In a postmodern world where nothing is sacred and life is experienced through the simulacra of the screen, the hyperreal takes over. I investigate how real-world socio-political issues, particularly those related to gender, transcend into the digital realm of cyberspace through discussions of Donna Harraway’s ‘cyborg feminism’ and Judith Butler’s ideas of gender performativity, as well as Erving Goffman’s ideas of everyday performativity. My final body of work for the professional art practice component of this MFA is realised in the form of an immersive installation that straddles the virtual and the real. Influenced by digital and hyperreal aesthetics (such as VapourWave), this installation also explores various expressions of femininity that an individual can express both online and in real life.
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The digital rhetoric of addressing rape culture: “official” and “unofficial” arguments at Rhodes University
- Authors: Jones, Megaera
- Date: 2020
- Subjects: Rape in universities and colleges -- South Africa -- Makhanda , Universities and colleges -- Administration -- South Africa -- Makhanda , Communication in higher education - South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/142621 , vital:38096
- Description: South Africa is overwhelmed with high levels of sexual violence and institutions of higher education in South Africa are not exempt from this. How higher education stakeholders have responded to the call to address rape culture on campuses has been at the centre of much attention, especially publicly on online communicative spaces. Drawing on contemporary rhetorical theories, informed by a feminist poststructuralist perspective, this study sought to explore how constituents at Rhodes University were discussing how rape culture should (and should not be) addressed on campus. Using a rhetorical analysis, this study collected and analysed online public data from ‘official’ (institutionally sanctioned) and ‘unofficial’ (institutionally independent) communication platforms, following the 2016 rape culture student-led protest at Rhodes University. In analysing and interpreting the data from the ‘official’ sites, four major themes of discussion were evident. These rhetors argued that rape culture is a societal issue, requiring collective responsibility and effort in countering it, and that any approach to do so must abide by the bounds of the law. The University’s commitment, and continued investment to address rape culture on campus were repeatedly stated; as well as, the use of external ‘supportive’ messages that bolstered the reputation, efforts, and actions of the institution. On the ‘unofficial’ sites six broad patterns of discussion were evident. These ‘unofficial’ rhetors embodied the rape culture on campus, perceiving its effects as threatening to the physical body, which led to the adoption of the argument that rape culture needs to be ‘fought’ through physical action and support. Narrow law and order approaches were contested, and the need for a victim-centred approaches were prioritised. Additionally, doubt and suspicion were cast onto the institutional management/leadership, and the University (management/leadership body) were perceived as having ‘failed’ to address rape culture adequality. Considering this ‘failure’, a divisive rhetoric argued that the ‘fight’ against rape culture should continue, despite, and separate from, the institutional body. These findings revealed how the divisive positions these various stakeholders took created a volatile climate between University management/leadership, staff, and student. I argue that such division will continue to undermine any meaningful efforts to counter rape culture on the University campus; underscoring the difficulty, and ambiguity, that comes with attempting to address rape culture on higher education campuses. This necessitates how important it will be for scholars to research, and continue researching, the ways in which a rape culture, and the various approaches which attempt to counter it, are understood.
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The effect of age and maturation on anthropometric characteristics and physical abilities of youth South African footballers
- Authors: De Beer, Ashley
- Date: 2020
- Subjects: Soccer -- Physiologial aspects , Soccer players -- South Africa -- Makhanda -- Physiology , Soccer players -- South Africa -- Makhanda -- Psychophysiology , Makana Local Football Association (South Africa)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/141222 , vital:37954
- Description: Currently there is limited research investigating the football related abilities of youth South African individuals. Populations from North and South America, Europe and Asia have been extensively covered in terms of their anthropometric characteristics, physical abilities, technical competency, tactical understanding as well as various personality traits. In describing these details, and especially how each is affected during the ageing and pubertal process, a more informed understanding of the talent development systems is created. A holistic approach to talent development is required to effectively and efficiently produce elite level footballers. An important consideration is the unique socio-economic environment many youth footballers experience which may impact on the talent development process. The present study therefore sought to quantify the anthropometric characteristics and the physical ability level of youth South African footballers from Local Football Association in Makhanda in the Sarah Baartman Region of the Eastern Cape province. In order to achieve this a two-factorial design was used with age and maturity status as independent variables. Anthropometric characteristics were tested by finding the height, weight, body mass index and total fat percentage of participants. Physical ability was determined by results for aerobic capacity, power, acceleration, speed and agility. All tests were football specific and had been widely used in a variety of footballing studies. Additional demographic and socio-economic information was also recorded. A total of 136 participants were placed in their respective Under 11, 13, 15 or Under 19 age groups, while the maturity status of 96 participants were stratified into five distinct categories. Statistical analyses was conducted using p-value significance, with appropriate Tukey post-hoc tests administered when necessary, while effect sizes were calculated using Cohen’s d. Significant changes and practical effect sizes were present for nearly all dependent variables when either stratified by age or by maturity. Total fat percentage was the only dependent variable which was not influenced by either age or maturity. Age and maturity effect sizes for total body fat percentage indicated practical changes present which did not occur during statistical analysis. The present results indicate poor values when compared to normative data or that of other football playing study populations. Further longitudinal research is required to better understand individual growth rates for youth South African footballers, particularly from the Makana region. Implications of the thesis may determine long term development pathways, while the delayed maturity rate is a critical finding which needs to be further researched.
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The effect of alginate supplementation on the growth, feed utilization, digestive enzyme activity levels, and intestinal morphology of juvenile South African abalone (Haliotis midae) fed formulated feeds
- Authors: Tlakedi, Thato
- Date: 2020
- Subjects: Abalones -- Feeding and feeds -- South Africa , Haliotis midae , Abalones -- Digestive organs , Abalones -- Morphology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145279 , vital:38424
- Description: Alginate occurs abundantly in kelp and while a few studies have quantified the effect of kelp inclusion in formulated Haliotis midae feeds, none have researched the effect of alginate inclusion on the growth of abalone fed this feed. Feeding kelp to cultured abalone affects gut structure and modulates gut bacteria, aiding digestion by upregulating enzyme activity. This farm-based experiment compared the growth, feed utilization, digestive enzyme activity levels and intestinal villi structure between abalone (1-year-old, 10 - 20 mm shell length) fed kelp-supplemented (BK) or alginate-supplemented (BA) diets and abalone fed basal (B) and fresh kelp (K) diets for a period of eight months from June 2017 to February 2018. Growth and enzyme activities were also compared between abalone that experienced dietary changes and abalone that remained on their initial diets. The tested diets were: base diet (B, 34% protein), the same base diet supplemented with fresh minced kelp (0.90% kelp [dry mass, equivalent to 0.20% alginate]; BK), base diet supplemented with sodium alginate (0.20% alginate; BA) and a fresh kelp diet (K). Alginate or kelp inclusion in a formulated feed had no significant effect on the specific growth rates (SGR), linear shell growth rates (LGR), daily percentage feeding rates (PFR), feed conversion ratio (FCR), percentage mass gain (MG) and condition factor (CF) over the eight month trial period, compared to abalone fed the base diet. In October 2017, four months since the start of the trial in June, all the groups fed formulated feeds showed significantly higher average weight gain (8.42 ± 0.72 g to 8.86 ± 0.63 g) compared to the kelp-fed group (6.68 ± 0.43 g). However, no significant differences in the average weight gain were observed between abalone fed kelp and formulated feeds at the end of this study. Furthermore, there were no significant differences in the FCR and PFR between abalone fed the base or alginate diets and abalone fed the fresh kelp diet. However, the SW diet produced significantly lower FCR (1.00 ± 0.13) and PFR (0.78 ± 0.10%) compared to the kelp diet (10.6 ± 1.40% and 8.12 ± 1.01%, respectively). All formulated diets produced non-significant LGR, MG and CF compared to the kelp diet at the end of this study. Enzyme activity levels were compared between abalone fed the test diets in July and August 2017 and February 2018. There were no significant differences in the average alginate lyase specific activity levels between abalone fed formulated diets in July and August 2017. At the end of the trial, however, the alginate diet induced significantly higher alginate lyase specific activity levels (4.89 ± 1.64 mg.mg-1 protein) compared to the base diet (1.57 ± 0.98 mg.mg-1 protein), but showed no significant differences compared to the SW (3.78 ± 0.41 mg.mg-1 protein) and fresh kelp-only diets (4.00 ± 0.62 mg.mg-1 protein). The SW diet showed no significant differences in the alginate lyase specific activity levels compared to the base diet. There were no significant differences in the chymotrypsin activity levels between the test diets throughout this study. Alginate or kelp inclusion also had no significant effect on the intestinal structure compared to the base or fresh kelp diets. This was despite a higher degree of variability in microvilli height and width being observed in abalone fed the kelp-only diet, with microvilli visibly wider and longer than in abalone fed formulated feeds. Switching abalone between some diets significantly affected the average weight gain, MG, FCR and PFR, alginate lyase, chymotrypsin and cellulase activity levels compared to abalone kept on their initial diets. The inclusion levels of kelp and alginate used in this study were likely too low to affect abalone growth as higher inclusion levels, particularly of alginate, have been found to improve fish growth. This study concluded that minced kelp and alginate inclusion in a formulated H. midae diet did not affect the SGR, FCR and intestinal morphology, but significantly affected alginate lyase and chymotrypsin activity levels. Furthermore, changes in growth and digestive enzyme activity levels coincided with dietary changes. Consequently, higher inclusion levels, particularly of sodium alginate, and the effect of dietary changes on abalone growth and digestive enzymes must be investigated in future studies.
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The effect of company brand on the investment decisions of individual investors as mediated by behavioural finance biases in Nigeria
- Authors: Okeja, Ogechukwu Donatu
- Date: 2020
- Subjects: Branding (Marketing) -- Nigeria , Business names -- Nigeria , Brand choice -- Nigeria -- Mathematical models , Consumer behavior -- Nigeria -- Mathematical models , Consumers' preferences -- Nigeria , Nigerian Stock Exchange
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/144015 , vital:38303
- Description: Over the years, the financial sphere and its systematic process has transcended from one paradigm to another. Most prominent is the traditional finance paradigm dominating the financial sphere majorly throughout the 1960s and 1970s. The ideology and the foundation of the traditional finance paradigm was centred on the concept of rationality. Within the context of the current research, the traditional finance paradigm postulates that individuals in the process of making investment decisions, acquire and analyse all available information in the stock markets, upon which they make a rational investment decision. In other words, the traditional finance paradigm portrays individuals as perfectly informed, rational decision makers, capable of objectively solving complex problems –Homo economicus. However, research in the field of psychology gave rise to the questions and concerns that started to emerge in the 1980s concerning the realistic nature of the assumptions of the traditional finance paradigm. As opposed to the assumptions of traditional finance, these research show that it is impossible for investors to analyse the shares of all the listed companies in the market in order to make rational investment decisions due to the ambiguous nature of information available. In the behavioural finance paradigm individuals’ decision making are viewed to incorporate factors such as emotions, heuristics, experiences, intuition and perceptions. These factors in turn are seen to induce biases (such as availability bias and overconfidence) which leads to subjective decision making. The concept of behavioural finance is based on realistic outcomes of events in the financial sphere for example, the repeated occurrence of financial crises in an environment where all participants are assumed to be rational. The behavioural finance paradigm challenges the assumption of the traditional finance paradigm which is embedded on the concept of rationality. The purpose of the present research is to investigate whether brands of listed companies on the Nigerian Stock Exchange trigger behavioural finance biases in investment decisions of individual investors in Nigeria. More specifically, the aim of the present research was to establish relationships between the independent sub-variables of brand knowledge (brand awareness and brand image) and brand relationship (brand loyalty and brand attachment), the mediating sub-variables of behavioural finance biases (availability bias and overconfidence) and the dependent variable (investment decisions). To this end, objectives and hypotheses were formulated to guide the research. In order to achieve the stated objectives and test the formulated hypotheses, the present research adopted the positivistic paradigm and the methodological process involved quantitative methods. Data was acquired by means of an online questionnaire from members of the Independent shareholders association of Nigeria and individual investors whose contacts were provided by an independent broker (n= 182). The research instrument showed satisfactory levels of validity on all measures (between 0.40 and 0.89) and a relatively highly internal consistency for reliability with Cronbach’s alpha coefficient scores of between 0.81 and 0.93. Descriptive and inferential statistical analyses were performed. Descriptive statistics involved frequency distribution, mean and standard deviation. Inferential statistics involved Spearman’s rank correlation coefficient, Multiple linear regression analyses, T-test and ANOVA. Using Spearman’s rank correlation coefficient, results show that all variables were positively correlated. Results of the Multiple linear regression analyses performed, indicated that there are positive relationships between brand awareness and investment decisions; brand awareness and availability bias; brand loyalty and investment decisions; brand loyalty and overconfidence; overconfidence and investment decisions. Furthermore, Multiple linear regression analyses also indicated that availability bias mediates the relationship between brand awareness and investment decisions; and overconfidence mediates the relationship between brand loyalty and investment decisions. Results of the T-test indicated that there is no significant mean difference found in the responses of the different sex group (male and female) on independent, mediating and dependent variables. While ANOVA indicated that there is a significant difference found between the age category of respondents and brand loyalty; age category of respondents and investment decisions. Based on the results of the analyses performed, conclusions, contributions and recommendations were enumerated. Practical recommendations were made to the government, individual investors, companies and brand experts, professional brokers, financial analysts and economy developers.
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The effect of technology acceptance model and trust on online banking in Zambia
- Authors: Hamusone, Collins Moonga
- Date: 2020
- Subjects: Internet banking -- Zambia , Banks and banking -- Computer networks -- Zambia , Banks and banking -- Information technology -- Zambia , Banks and banking -- Technological innovations -- Zambia , Consumer behavior -- Zambia
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/163637 , vital:41063
- Description: The banking industry has been influenced by the evolution of technology and in the process , reduced the cost of transacting and increased the speed of service delivery. This global change has been driven by the development of alternative banking channels from the traditional brick and mortar walls to a utomated teller machines , phone - banking, and now the most recent phenomenon, online banking . The current study, conducted in Lusaka, Zambia investigated the adoption of online banking technology using the Technology Acceptance Model (TAM) with perceived ea se of use, perceived usefulness and trust. T he two constructs perceived ea se of use, perceived usefulness are known to be the most accurate subjective measurement scales for predicting user acceptance . T echnology Acceptance Model (TAM) is the most widely used model and theorizes that if a user fi nds the technology useful , it will influence the user’s attitude positively, thereby increasing the intention to use and finally allowing for adoption. In a cross - sectional survey of 478 participants, and using logistic regression, this study found that perceived usefulness , perceived ease of use and trust were positively associated with users’ intentions to adopt online banking , and these relationships were statistically significant. The findings from this study provide support for the theoretical model. The study further found no contradicting results, and this provides banks in Zambia with an opportunity to grow online banking as the consumer behaviour indicates a willingness and int ention to adopt the technology. The current study was limited to the urban areas of Lusaka which had a population of 3.2 million . Future research may also investigate the impact of culture on the adopti on of online banking technology .
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The effects of education on economic growth and global competitiveness: a statistical approach
- Authors: Mbatha, Erica Isabel Tavares Da Silva
- Date: 2020
- Subjects: Economic development -- Effect of education on -- South Africa , Education, Higher -- South Africa , Educational attainment -- South Africa
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/147558 , vital:38649
- Description: This thesis investigates whether there is a relationship between education, economic growth and global competitiveness and whether there is a relationship between South Africa’s current throughput rates in institutions of higher education, and its economic growth and global competitiveness. Economic growth is defined as a country’s ability to improve the life of its average citizen based on the strength of its economy. As such, it is increasingly important for a country to assess the factors that contribute to the improvement of their economy, which will ultimately result in its economic growth. Global competitiveness is an indication of how countries are able to provide for their people internally, as well as participate in the international market. To this end, economic growth and global competitiveness are two proxies that can be used to demonstrate the economic wellbeing of a country. Considering that prosperity under economic growth and global competitiveness of a country are driven by its people, one of the aims of this thesis was to investigate whether there is a relationship between education and economic growth and global competitiveness. Considering the recent demand in free education in South Africa, it is also important to understand whether there is a relationship between South Africa’s current throughput rates at higher education institutions and its economic growth and global competitiveness. Bearing in mind the political past which has led to inequality in the country, it is important to understand which types of education contribute to the economy and which types need to be further supported in order to increase the country’s economic productivity. Therefore, an additional aim of the thesis was to determine the relationship between South Africa’s current throughput rates in institutions of higher education, and its economic growth and global competitiveness. To address the aforementioned aims, data were collected from various open access online repositories. All the data were collated and numerous general linear models were constructed and tested to determine the different relationships as per the two aims. The results reveal that secondary school education had the highest impact on economic growth and global competitiveness on a global scale. This could be attributed to the fact that secondary school graduates tend to make up the largest part of the general workforce and as such, would make up a substantial proportion of the economy. Regarding South Africa, the only significant relationships were between green cluster universities (universities that focus on both research and technical training) and global competitiveness. Overall average throughput rates in all academic institutions were low; this could indicate that perhaps there are issues within the higher education system itself that need to be addressed in order to increase the throughput rate. From a managerial perspective, the results of this research stress the importance for the government to further investigate this area of study, as the call for free education becomes more prominent. The low throughput rates seem to suggest that the government is spending substantial amounts of money on students who do not always complete their studies. More research needs to be done to assess the root of the problem in South Africa’s tertiary education system, in order to ensure that this aspect increases its positive contribution towards the country’s economic growth and global competitiveness.
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The effects of elevated atmospheric CO2 on the biological control of invasive aquatic weeds in South Africa
- Authors: Baso, Nompumelelo Catherine
- Date: 2020
- Subjects: Aquatic weeds -- Biological control -- South Africa , Plants -- Effect of atmospheric carbon dioxide on , Atmospheric carbon dioxide -- Environmental aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/140772 , vital:37917
- Description: There has been a rapid increase in atmospheric CO2 concentration, from pre-industrial values of 280 ppm to more than 400 ppm currently, and this is expected to more than double by the end of the 21st century. Studies have shown that plants grown above 600 ppm tend to have an increased growth rate and invest more in carbon-based defences. This has important implications for the management of invasive alien plants, especially for the field of biological control which is mostly dependent on herbivorous insects. This is because insects reared on such plants have been shown to have reduced overall fitness. Nevertheless, most of the studies on potential changes in plant-insect interactions under elevated CO2 are based on agricultural systems, with only a limited number of these types of studies conducted on alien invasive weeds. However, climate change and invasive species are two of the most prevalent features of global environmental change. Therefore, this also warrants active research and experimental studies to better understand how these systems will be affected by future climates. Thus, the aim of this study was to investigate the effects of elevated atmospheric CO2 on the biological control of four invasive aquatic weeds (Azolla filiculoides, Salvinia molesta, Pistia stratiotes, and Myriophyllum aquaticum). These species are a threat to natural resources in South Africa but are currently under successful control by their biological control agents (Stenopelmus rufinasus, Cyrtobagous salviniae, Neohydronomus affinis, and Lysathia n. sp.). To achieve this, the selected plant species were grown in a three-factor experimental design in winter (CO2 X nutrients X herbivory), and another two-factorial design in summer (CO2 X herbivory). Atmospheric CO2 concentrations were set at ambient (400 ppm) or elevated (800 ppm), as per the predictions of the IPCC. As per my hypothesis, the results suggest that these species will become more challenging in future due to increased biomass production, asexual reproduction and a higher C: N ratio which is evident under high CO2 concentrations. Although the biological control agents were in some instances able to reduce this CO2 fertilisation effect, their efficacy was significantly reduced compared with the levels of control observed at ambient CO2. These results suggest that additional biological control agents and other management methods may be needed for continued control of these invasive macrophytes, both in South Africa and further afield where they are problematic.
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The exploration of ARF1 screening assays to determine the drug status of ARF1 in cancer and malaria
- Authors: Ntlantsana, Apelele
- Date: 2020
- Subjects: ADP ribosylation , Golgi apparatus , Guanosine triphosphatase , G proteins , Malariotherapy , Malaria -- Research , Cancer -- Chemotherapy , Malaria -- Chemotherpay
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167232 , vital:41458
- Description: ARF GTPases are key regulators of the secretory and endocytic pathways. ARF1 is involved in the secretory pathway. ARF1 has been implicated in the endoplasmic reticulum to Golgi transport, function of the Golgi apparatus and transport from the trans-Golgi network to endosomes. ARFs cycle between active GTP-bound and inactive GDP-bound conformations. GDP/GTP cycling is regulated by large families of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). ARF GEFs facilitate the activation of ARFs by mediating the exchange of GDP for GTP, while ARF GAPs terminate ARF function by stimulating the hydrolysis of the terminal phosphate group of GTP. Based on existing evidence gained from gene manipulation and cell biological investigations, ARF1 has been shown to be fundamentally important for cancer cell proliferation and metastasis and may be a promising target for the development of anti-cancer drugs. Additionally, the conservation of ARFs in eukaryotic organisms leads to an interesting question of whether a single drug target can be used to target multiple diseases. In this case, can a human cancer drug employed for cancer therapy be used in anti-malarial drug therapies? To confirm the drug target status of ARFs using chemical validation experiments, novel inhibitory compounds are needed. This requires the development of complex in vitro protein- protein interaction assays that can be used to screen chemical libraries for ARF GTPase inhibitors. In this study, we developed a fluorescence resonance energy transfer (FRET) assay and a novel in vitro colorimetric plate-based assay to detect the activation status of truncated human and Plasmodium falciparum ARF1. In the case of the FRET assay, active (GTP-bound) and inactive (GDP-bound) ARF1 could be distinguished with Z-factor values >0.5, suggesting that further development of the assay format to identify GEF and GAP inhibitors may be feasible. In the case of the colorimetric assay, robust signals could be detected and the assay was useful for detecting the activation status of ARF1. However, although the activation of ARF1 by the Sec7 domains of the BIG1 and ARNO was detectable, signals were not robust enough to employ in screening campaigns.
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The frightened
- Authors: Msimang, Lethokuhle
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/144004 , vital:38302
- Description: My novella tells the coming of age story of a young woman battling the trauma of objectification. It explores the intimate relationship between a woman and a man, the young and the old, and the camaraderie between women. Having spent the greater part of her youth in various parts of the world, my protagonist faces the stark reality of returning home to her native country. This triggers an angst which causes her to leap between lived experiences and memories. An elegy on how difficult it is to love while dragging the long shadow of shame, it uses short prose and prose poetry to reveal the intimacies and intricacies of self hate and clandestine romances, and to unravel the complexities of memory and forgetting. Built from non linear fragments it seeks to refuse cliches regarding love and to question easy assumptions around gender, family and the innocence of youth. I draw inspiration from Vita Sackville West’s’ All Passion Spent , which eloquently portrays the placid and flickering thoughts of an old woman taking leave from the frivolity of youth. I’m similarly inspired by the sincerity and confessional aspects of Virginia Woolf and French poet and photographer Alix Roubaud ’s journals and Van Gogh’s letters, as well as Lydia Yuknavitch, Max Porter and Elena Ferante’s autobiographical fiction. I also draw from J’Lyn Chapman’s chapbook A Thing of Shreds and Patches and finally Dostoevky’s Notes from Underground , for their blurring of life and writing, and their exploration of grief and death as a lingering thought, together with the oppressive urge to create. In addition I’m inspired by the poetry of a new generation of South African female writers like Vangile Gatsho.
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